How to highlight the cost advantage of mold manufacturing
with the development of mold manufacturing from skilled to scientific, the traditional method of manufacturing auto panel mold based on main model and drawing graphics is gradually replaced by the method of converting the digitally described auto panel shape into processing trajectory by cad/cam terminal. Using the line remote control processing process will push the scientific level of mold manufacturing to a new height. Looking back on the past, when processing steel molds for punching automobile outer covers, it is necessary to draw a detailed blueprint and have a master model manufactured according to the precise size of the punched parts. It can be said that the model is the master mold designed and made into the mold
first, when manufacturing molds by casting method, it is necessary to prepare wood molds or sample parts of automobile parts. The model made according to a certain proportion is called profiling, which is often used as the master mold in profiling processing, or as an auxiliary model to display the machining path of milling machines. The profiling finger on the profiling milling machine moves along the profile shape of the profiling, and the milling cutter milling the mold material according to the movement of the profiling finger to simulate the required mold cavity. Now the processing method has undergone fundamental changes. The CAD data provided by the customer generates the cutting path of the milling cutter, and automatically processes the stamping die of the automobile panel and the cavity die for plastic sheet molding
although the new process of using and realizing industrial trial production can process the two mating surfaces of the mold more accurately than the previous processing methods, it is also necessary to test the mold and measure the sample for pressing. Usually, the main cavity surface of the die is processed correctly from CAD data, and then the wear prevention pad and other parts are matched with the main cavity surface. Now the characteristics of this new technology can be summarized into the following aspects
second, there is no need for the main model and profiling. Although the main model and profiling are no longer used, the machining accuracy has been improved.
for example, when the machining tolerance is very strict and the mold that needs manual polishing after grinding the main cavity surface, the effect of machining with CAD data is better than that with the main model and profiling. The main difference is that the size control has been fundamentally improved. When the cavity mold of plastic parts is processed by traditional methods, the processing tolerance will change with the temperature every day. Although the processing accuracy of the die used for plastic sheet molding is also very good, the hot pressing of plastic sheet does not rebound like stamping metal sheet, so after the precise control of processing by CAD data, there is generally no need to test the die. For this kind of mold, as long as it passes the routine customer verification, it is generally no longer necessary to submit parts
this is mainly because CAD data processing is used to test the processing results, and mathematical analysis can also be carried out on the mold cavity surface, so as to ensure that the manufacturing process can be implemented in strict accordance with the original design data. It is precisely because the manual operation in the mold manufacturing process is eliminated that the competitiveness in mold accuracy and processing cycle is improved
for this reason, the application of CAD data for mold processing technology has been promoted in most mold manufacturers. Now the experience of many factories can confirm that after the application of this technology, although the tool path time generated by cam has increased by 14%, the time for polishing has been reduced by 33%, the total processing time has been shortened by 16.5%, and the quality of the mold has been improved by 12%. Now, various cad/cam software can help engineers design molds and generate tool paths of CNC milling machines. The system can also display 3D color stop rising model on the screen for mold design and analysis. It can also provide finite element analysis for improving casting quality and thermal performance analysis of molds. In fact, any customer's database can be directly used for input, or input after conversion
III. inspection by CMM
the CMM used to cooperate with cad/cam system for inspection is also different from the movable CMM originally suitable for traditional tooling molds. The CMM used now is equipped with automatic measurement system
how does this CMM do strength tests on ceramics? The positioning accuracy of any point in the 3250x2090x1370mm measurement space is 0.015mm
the part mass of stamping die or plastic die that can be measured is 40 tons. In order to maintain the highest measurement accuracy of the measuring machine, it should be placed in an independent machine room isolated from the external environment, and the room temperature should be maintained at 20 ℃. In order to prevent the vibration from adversely affecting the measurement, the measuring machine should be installed on a 100 ton concrete base supported by an air cushion
in machining, CMM can not only be used as a tool for final inspection of mold quality, but also as a tool for inspection of machining process. That is, in the process of processing, half-way inspection is carried out after each process is processed. For example, inspect the main cavity surface of the processed mold. In particular, before polishing, the machined surface should be comprehensively inspected in order to determine how to achieve the required geometric shape of the machined surface more accurately
when inspecting the mold, it is necessary to pass through all parts with dense streamline. Each mold needs to be inspected twice. One is before stamping and the other is after stamping. Apply the theoretical calculation thickness to measure the alignment of the upper and lower mold cavities, so as to grasp the actual situation of realizing the accuracy of CAD design data
IV. characteristics of plastic sheet molding mold
the mold used for molding plastic sheet is different from the mold for stamping metal sheet. It has no problem of material rebound. Therefore, when processing this kind of mold, it is not necessary to adjust the alignment condition of the mold, but to focus on the surface condition of the plastic parts. That is, focus on the surface accuracy and shape accuracy of the surface
v. management of processing process
the network using the above system is usually composed of a small calculator and a personal calculator terminal. An effective management system. (effectivemanagementsystem - EMS) software can track and manage the processing process. For example, master the processing progress, parts circulation, purchasing status of purchased parts, receiving status and processing quality. This management system also includes bill of materials, planning and control, inventory management, standard castings, material resume, total production schedule, required material plan, ordering and sales history, arrival quantity, operator resume, control status of the workshop, planned time, quality evaluation, standard processing route, required production capacity plan, labor cost, outsourcing plan and arrival status, purchase requisition, History and deliverable quantity of purchased parts, etc. Using this software, you can choose the right time to purchase goods and save labor
make all processing status information completely into inventory management, so as to generate a perfect bill of materials. Then process in an orderly manner according to the processing route. The system also provides operators' processing hours and machine tools day by day, which mainly depends on the data of the company's overall horizontal operation time and the time of downtime. This can not only reduce the time of machine tool vacancy, but also calculate the actual production cost, so as to achieve the purpose of reducing production costs
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