automatic cnc machine es36 Slow wire processing can you solve these problems? The slow-moving wire machine is a high-precision machining machine, which can achieve a processing accuracy of several μm, and the surface roughness Ra can reach <0.2μm. However, some mold factories do not pay attention to details when using slow wire machine tools, thinking that a good machine tool can casually achieve efficient high-precision machining. But in the operation will also encounter a variety of problems, what are the best ways to deal with these problems?
1, slow wire processing old broken wire, what to do?
The broken wire is one of the most common problems in slow wire processing. After the broken wire occurs, it is necessary not to modify the parameters arbitrarily. The possible causes of broken wire should be determined according to the processing situation at that time, and then the corresponding measures should be taken.
1) The upper surface of the cut parts has large ups and downs
Countermeasures: The upper surface of the cut parts has large ups and downs, the upper and lower water spouts can not be veneered, and the wires can not be broken due to effective high pressure flushing. This situation occurs in roughing, can be reduced by reducing the discharge energy to avoid breaking the wire, the priority to reduce the discharge power P value, after a substantial reduction will still break the wire value and then consider reducing the discharge current I, reducing P will reduce some processing efficiency, but reducing the discharge current will greatly reduce the processing efficiency.
2) Can not effectively flush high pressure
In 1), the type of effective high-pressure flushing can not be achieved, but that is determined by the workpiece, we can not change the workpiece. In actual processing, there are a lot of ineffective high pressure flushing that can be improved artificially. For example, the distance between the upper nozzle and the upper surface of the workpiece is too large, this situation is not correct, to reduce the distance between the upper nozzle and the upper surface of the workpiece as much as possible, such as the distance should be controlled at about 0.1mm when processing the plate; In addition, check whether the upper and lower spray nozzle is damaged, if damaged, please replace it in time.
3) Improper electrical parameters
Countermeasures: Please carefully check whether the selected discharge parameters are correct, whether the wrong workpiece height is selected, the wrong electrode wire type is selected, and so on; If the discharge parameter itself is not stable enough, it can be improved by reducing the P-value to reduce the pulse discharge energy. If the tension value in the parameter is too large, the electrode wire will be pulled off and the wire tension will be reduced, especially in taper processing; Low wire speed in roughing will lead to broken wire, adjust if necessary.
4) Electrode wire, workpiece material quality problems
Countermeasures: The quality of the electrode wire used is not good, coil stacking, oxidation, etc., should be replaced with high-quality electrode wire; Reduce the P and I values until the thread is broken,
5) The conductive block is seriously worn or too dirty; The guide wire is too dirty, causing scratching
Countermeasures: The wear, surface roughness (oxidation) and connection of the conductive block and brush should be checked; Clean, rotate or replace the conductive block; Clean the wire guide parts
6) The silk is not smooth, and the balance wheel wobbles
Countermeasure: wire fluctuation. Use a tensiometer to check the tension of the electrode wire and adjust it.
7) The waste wire in the waste wire bucket overflows and contacts with the machine tool or the ground, resulting in short circuit.
Countermeasure: Put the spilled waste silk back into the waste silk bucket, and clean up the waste silk bucket in time.
2, slow wire processing efficiency is low, what to do?
1) No veneer processing, reducing P and I values
Countermeasures: Adjust the Z axis, veneer processing as far as possible, in the case of must reduce the P value or I value to be moderate, can not reduce too much.
2) Improper electrical parameters
Countermeasures: According to the processing requirements, select a reasonable process sequence file; Check whether the ACO adaptive function is selected. When the cutting state is stable, the ACO can be canceled; In case of many corners, the machine tool will use the corner strategy, and the corner strategy can be appropriately reduced according to the processing accuracy requirements.
3) Workpiece deformation, repair and repair do not move; Repair mold, the main cut is not limited, repair a slow speed
Countermeasures: reasonable arrangement of technology to reduce material deformation; When repairing the mold, the main cut set a reasonable speed limit value to avoid too fast speed and the margin is not cut in place.
4) The main cutting efficiency is lower than before
Countermeasure: Timely maintenance of machine tools. Need to check whether the conductive block cooling water is normal; Check whether the guide wheel rotation is flexible; Whether the take-up wheel is normal; Check the tension and speed of the wire, and adjust it if necessary; Check and clean the guide nozzle and conductive block.
3, how to prevent the temperature difference to slow wire processing error?
1) High precision slow wire processing to ensure the working accuracy of the temperature range of 20±1o, can not achieve this condition, the most important condition is to control the temperature fluctuation range, preferably not more than ±3o.
2) Before working, the parts are soaked or washed in the working liquid for a period of time, and then rectified and processed, which is conducive to ensuring accuracy.
3) The larger parts are best completed in a boot, if there is a long time to stop processing in the middle (such as a night), it is difficult to ensure processing accuracy. If the downtime is more than two hours in a processing, it should also be flushed for more than half an hour before continuing processing to reduce the error caused by the temperature difference.
4, processing punch how to prevent cutting deformation?
In the actual production and processing, due to the residual stress deformation and thermal stress deformation caused by discharge in the workpiece blank, the wire hole should be processed for closed cutting first, and the deformation caused by open cutting should be avoided as far as possible.
If you are limited by the size of the workpiece blank and can not be cut in a closed form, for square blank parts, attention should be paid to choosing a good cutting route (or cutting direction) when programming. The cutting route should be conducive to ensuring that the workpiece is always in the same coordinate system with the fixture (clamping support frame) during the processing to avoid the influence of stress and deformation. The fixture is fixed at the left end, from the left side of the gourd punch, cut in a counterclockwise direction, and the whole blank is divided into left and right parts according to the cutting route. As the material connecting the left and right sides of the blank is cut smaller and smaller, the right side of the blank is gradually separated from the fixture, unable to resist the internal residual stress and deformation, and the workpiece is deformed. If cutting clockwise, the workpiece remains on the left side of the blank, close to the clamping part, most of the cutting process makes the workpiece and the fixture remain in the same coordinate system, rigidity is better, to avoid stress deformation. Under normal circumstances, a reasonable cutting route should arrange the cutting section that separates the workpiece from the clamping part at the end of the total cutting program, and leave the pause point (support part) near the clamping end of the blank.
5. What is the cutting process of high-precision multi-type hole and concave template?
Before slow wire processing, the template has been cold and hot processed, and a large residual stress has been generated inside, and the residual stress is a relatively balanced stress system, and when a large amount of waste is removed by wire cutting, the stress is released as the balance is destroyed. Therefore, when the template is in wire cutting processing, with the effect of the original internal stress and the influence of the processing thermal stress generated by the spark discharge, it will produce non-directional and irregular deformation, so that the thickness of the cutting tool behind is uneven, affecting the processing quality and processing accuracy.
In view of this situation, the template with relatively high precision requirements is usually used for 4 cutting processing. The first cut will cut all the waste of the type hole, remove the waste, and then the automatic shift function of the machine tool to complete the second, third and fourth cuts. a cut the first time, take the waste →b cut the first time, take the waste →c cut the first time, take the waste →... →n cut the first time, take the waste →a cut the second time →b cut the second time →... →n cut 2nd →a cut 3rd →... →n cut the 3rd time →a cut the 4th time →... →n Cut the 4th time, the processing is complete. This cutting method can make each type of hole after processing enough time to release the internal stress, can reduce the mutual influence of each type of hole due to different processing sequence and trace deformation to a minimum degree, and better ensure the machining dimensional accuracy of the template. However, this processing time is too long, the number of threading times, the workload is large, and the manufacturing cost of the template is increased. In addition, the machine itself will creep with the extension of processing time and temperature fluctuations. Therefore, according to the actual measurement and comparison, if the processing accuracy of the template allows, the first unified processing can be used to take the waste unchanged, and the following 2, 3 and 4 times are combined together for cutting (that is, after the second cutting of a, no displacement, no disassembly, and then the third and fourth times →b→c... →n), or eliminate the fourth cut and make three cuts. After the cutting is measured, the shape and size basically meet the requirements. This not only improves the production efficiency, but also reduces the labor, and therefore also reduces the manufacturing cost of the template.
automatic cnc machine es36 Slow wire processing can you solve these problems? figure
6, how to arrange the long-term unmanned operation of multi-cavity parts?
(1) For some multi-cavity parts with large cutting workload, it can be arranged at night and processed by unmanned operation, which can save costs and improve the utilization rate of machine tools. Multiple cavities should be set their own suspension amount, leaving a section of not cut, to ensure that the parts do not fall off, the rest of the outline for multiple cuts to the processing requirements, in the suspension position, the machine automatically cut the wire, move to the next cavity of the wire hole position, the machine automatically through the wire, and then continue processing. The process of cutting, shifting, threading and machining is performed several times until all cavities are finished. This can make the cutting process without core falling, without personnel intervention, to be cut off and pick up materials with personnel intervention, to complete the processing of the suspension section. In order to ensure the smooth progress of automatic threading during the processing process, the diameter of the threading hole should be as large as possible.
(2) For the processing of multiple small cavities, because the core is relatively small, it is not easy to set the suspension amount, and it is easy to short-circuit phenomenon, and the coreless cutting method can achieve the purpose of unattended machines.
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