The process is generally based on customer (transformer manufacturer) requirements of the detailed structure of the design, the current design for the customer skeleton, by the skeleton manufacturers according to the design of a good skeleton directly open mode. But there are a few cases that customers provide samples or simple design drawings, by the skeleton manufacturers with the completion of the early design work. Skeleton in the design, we should pay attention to the following details of the problem, in order to reduce the production often occur some bad.
① in the skeleton design early, designers need to clearly understand the skeleton in the customer's use. Including the customer's transformer product requirements, such as the size, etc .; transformer production process and the production conditions of the process, such as solder temperature, solder time, baking temperature, winding way; with the skeleton with the core model, size The In short, the skeleton in the use of the client when the precautions, be sure to understand clearly in order to better carry out the next design work.
② in the skeleton structure design, should be based on customer drawings or samples, plus their own design experience, try to 3D model design, to avoid 2D drawings and modify the defects, and then gradually modify, and eventually finalized. If the customer design is unreasonable, should take the initiative to propose with the customer technical staff to re-confirm the skeleton structure. Skeleton in the design, we should pay attention to the following aspects:
1. Raw materials must meet the customer's process and requirements, must be based on the characteristics of the material skeleton design. Generally refer to the yellow card to confirm the skeleton wall thickness; at the same time with the yellow card shows the temperature, and customer process baking and solder temperature for comparison, whether to meet the customer's process conditions. Such as GE N300X raw material RTIElec temperature of 105 degrees, the customer baking temperature of 130 degrees, obviously this material is not in line with customer process conditions.
2. Metal pins, can successfully pass or paste the client side of the PCB board, the general use of iron (steel) quality pin more. For customers have special requirements pins have better conductivity of the situation, the need to consider the use of copper and other conductive materials better.
3. At present, RoHS, halogen-free, SVHC and other environmental requirements more and more urgent, the selection of materials at the same time to meet these requirements.
4. To meet the transformer model requirements, dimensions need to be smaller than the transformer finished product size.
5. Core hole to match the core size of the column, generally larger than the upper limit of the magnetic core; fixed core of the blade is generally lower than the inner diameter of the core tolerance is smaller. The purpose of this design is to facilitate the subsequent wear mold repair. Posts type skeleton in order to meet the customer's automatic winding operation in the elastic requirements (loose with the loose process will make the skeleton off, tightly the operator is difficult to insert or pull out), core and wire fixture With the tolerance should be controlled at 0.05 or so.
6. The cableway is the wire path of the copper wire. At the same time, in order to avoid the occurrence of damage in the production, pin break, sand and other abnormal situation, so the width of the trough to be considered: the diameter of copper wire, pinhole Edge wall thickness, burr processing sand size. Under normal circumstances, over the trough for bigger, so you can avoid sand, but also to facilitate customers over the copper, but after the trunking, the remaining pinhole edge thickness will be too small, easy to produce pin Cracked feet.
7. pinhole should not be too deep, the bottom of the pinhole wall thickness to ensure that more than 0.5mm, to avoid the pin when the insertion or insertion hole defective.
8. Need to do R-angle transition, in addition to increasing the intensity to prevent damage, but also to improve the production of some of the problems. Especially the edge of the trough, to prevent the outer layer of the insulating coating of copper wire scratches; core hole edge can facilitate the insertion of the core; around the tube can increase the strength of the blade.
9. Need to design the anti-reverse structure of the pin to the best effect of the bump, so that the corresponding direction in the runway to increase the groove and the corresponding bump, to avoid the product caused by the wrong feet wrong.
10. High wall or larger blade frame, need to design stripping slope, easy to produce mold release.
11. When the skeleton has a cover, you should pay attention to the size of the mating parts.
12. Posts in the middle of the bobbin tube, should design the corresponding hook to prevent the wire when the wire is not in place; leaves should also design the gap, so that the needle through the smooth.
13. The best design of the mouth of the mouth of the gap, depending on the size of the skeleton, the general depression of the gap 0.5-1.0mm. This avoids the appearance of the product due to the residual material at the time of feeding. If you can not design a gap, increase the grinding of the feed inlet fixture to meet the size requirements.
14. Thick wall thickness of the plastic skeleton, should be designed in the plastic place more than the gap, try to ensure uniform wall thickness, to avoid serious shrinkage phenomenon.
③ mold design and manufacturing. A customer is only the sample and the development of the sample, the mold can generally design a hole or two points to proofing production for the purpose of the customer in particular the requirements of small batch production, the mold can be heat treatment or better steel.
1. Batch production of products, in the design of the product can be arranged in a straight line, so that mold cavity, runner, exhaust groove processing.
2. Before the mold, after the mold and the slider with each other parts, should be designed with the slope, to avoid direct collision and mold damage.
3. The deeper parts of the cavity (such as the bottom of the bump or retaining wall), should be designed to draw off the slope and the exhaust hole, so that when the smooth flow and reduce the occurrence of less material.
4. Mold inserts specifications as general and easy to replace the cleaning, in order to timely replacement and maintenance.
④ sample detection and recognition stage. Engineering or business in the sample, the product must be rigorously tested and checked:
1. Product size, especially in the important parts of customer requirements, wall thickness as the focus of control.
2. Strength test, the general skeleton can reach 3Kgf, for the structure is relatively thin or small products, the intensity is relatively small.
3. Withstanding voltage test, through high pressure test (such as 3.5KV, 2mA, 60S pressure conditions), in the design phase to avoid the selection, the wall thickness is irrational caused by poor pressure.
4. Solder test, test pin on the tin situation, and by the moment (1-3S) after the deformation of the body temperature, blistering. E product flatness, testing and PCB board contact with the bottom of the bump or plane, whether there is warping deformation of the situation, the general industry to 0.1mmmax as the standard control, the larger the skeleton, the degree of smoothness can be relaxed. The current post-type skeleton of the pin-level control of the most stringent control, because the pin is a direct link with the PCB flat posts linked to the control point.
5. CPK confirmation is required when the customer has requested CPK control for important parts.
6. After confirming the product, the customer shall keep the approval document for the sample and the customer. 7. Information documents (product specifications, operating standards, the entire inspection instructions, packaging specifications, etc.) to be issued to the relevant departments, so that the subsequent mass production of product quality control.
8. When the skeleton changes, change the logo on the picture, increase the detailed record of the version change; at the same time to isolate the product before the change, to avoid the mold before and after the mold mix.