Experience of Injection Mold Design
First of all, we get a product, the first do not rush to die, the most important thing is to first check the product structure, including draft, thickness and other molding problems. Of course, these are just engaged in a mold structure design of the people, it may be more difficult. Because they may not know how to be more suitable for mold design with the product, which does not matter, but their daily accumulation of a process. When you analyze the product of the draft, wall thickness, and in the direction of the mold out of the place, you basically have to know the direction of the mold parting, and the location of the gate, of course, these eventually still with the customer confirmed.
Some people say, is not my analysis of the product structure, you can start to design the mold, the answer is of course NO. To minimize the detour in the design, some of the items on the impact of the mold structure is sure to confirm the good. The specific content is as follows: 1, the customer used to produce the injection molding machine tonnage and model type, this confirmation is not good, you can not confirm your mold gates of the inlet diameter and positioning circle diameter, Position, as well as injection molding machine into the depth of the mold, or even the size of the mold, closed height and so on. You worked hard to design a set of cylinder with the core of the mold structure, you also quite a sense of accomplishment, mold to the customer where there is no production, because customers only electric injection molding machine, and no additional neutrons, it is estimated that You will have a feeling of tears. 2, the customer injection molding machine mode, commonly used is the pressure plate code, screw mold, hydraulic code, magnetic code, and so on. This confirmation is good, you know you design the mold, in the end need to design a code screw hole or code slot. 3, we have just analyzed the product after the problem, as well as product line, product materials and shrinkage. Do not take it for granted that PP plastic shrinkage must be 1.5%, this must be confirmed with the customer, to know what they are ultimately used for the production of what is the brand, there is no added modified materials and so on.
Conditional, it is best to be familiar with the product assembly relationship and the use of the product, etc., these information for the future design of the mold structure is very helpful. Because to understand these, you know what is the appearance of the surface, which is non-appearance, where the angle of the draft can be arbitrarily increased, which can not be changed. Even including the structure of some products, if you understand the actual assembly of the product and use, you know what inverted structure can be canceled or changed into another simple form. Be sure to remember that the process of making molds is the process of simplifying the problem. Often see some people to do a set of how complex structure and proud, I think it is very ignorant. Because many product engineers may be due to their own experience, the design of some less reasonable structure, if the downstream process, can not help them correct, they may always feel that design is no problem. The progress of our product engineers will be very slow.
Mold waterway external parameters, oil circuit external parameters, circuit external parameters, airway external parameters. Only in the design before understanding the customer requirements, you can have a predictive design of the waterway road, do not work hard to design a good mold, and later found that customers need to die in the mold inside the tank, then you Change, it is estimated that will be tired to die, because you waterway, mandrel, screw what is finally easy to row bit. Like the design of the four-way is generally the first to ensure that the oil, because the oil to the distribution of balance, especially the need for the cylinder out of the mold structure, if the oil is not balanced, the action will be out of the cylinder, Out of balance. Of course, can also use the gear oil separator, but that is more complicated.Second is the waterway, because the water to ensure that the cooling effect, uneven distribution will affect product quality and die life. The last is the gas path with the circuit. The order of placement on the mold is that the line closest to the TOP direction is the circuit, then the waterway, the airway, and the bottom is the oil circuit connector.
Other matters. With this information, we can start designing the mold. The first is the sub-model, this process is estimated that we are more like the process. Because there is a sense of accomplishment. Pull the principle of the surface is simple, that is, can be stretched out of the firm does not scan, or use other high order. Followed by drawing sub-surface when there is a big picture, try to simplify the sub-surface, do not engage in seventy-eight hundred and eighty-eight, if not precision molds, those 0.1 to 0.5 of the insertion of the bit to avoid. Another sub-surface also follow a principle, is to try to do along the product trends. That will be out of the sub-surface will be beautiful. String inserted a digression, in the study of three-dimensional software, we must remember that the principle of each command are clear, then you know when to use that command. It is not important that you will not use software, but you will not learn to use software. The same command, experienced people will have a lot of flexible usage, which is reflected in the UG is the most obvious. In a word, it is important to think, not the tool itself. When you do the sub-surface, only need to know, insert the angle of the face can be large, touch the surface area can be large, pull out the pillow wide and wide. To take full account of your hand now pull the part of the face in the future to do the actual mold, the workshop is responsible for the master of the model will not call you on the line. If you do not feel scolded, then OK, continue, when the future you really scolded, these are your experience.
In the sub-surface at the same time is certainly to consider the arrangement of the slider with the sloping roof, because those who have to involve the sub-surface changes. Typical slider structure is the trigonometric function of the relationship, this is nothing to calculate their own on the line, but to ensure that the angle of the diagonal column should not be too much, try to do 30 degrees below. Diagonal guide column selection principle is rough to coarse, do not be too small gas, because the diagonal column is to force. In addition, the slider is also divided into many variations of the structure, for example, uphill sliders, downhill sliders, inner pumping sliders, cylinder pumping, front mold sliders, slides with sliders, slides with anti- Sloping roof, etc., these special structures are full use of the trigonometric function of the relationship, the purpose is to achieve the product buckle off the mold, and the mold of the normal opening and closing mold action. Slider of the calculation of the major forums have a detailed introduction, I will not go into here.
Followed by the sloping roof, inclined top more flexible, but the typical angle of the top of the ramp should not be too much, try not to more than 15 degrees, of course, you have to do 20 degrees also, but life is difficult to guarantee, and the action will be Not smooth, the specific principle of reference to trigonometric and theoretical mechanics. The shape of the sloping roof has many forms of evolution, for example, uphill sloping roof, downhill sloping roof, crooked neck sloping roof, mosaic pliers of the big slanting, mosaic round bar of the big slanting, Small sloping roof, the top block below the top of the ramp, the slider on the top of the ramp, the top of the sloping roof, the top of the ramp with anti-top, and so on, all of these structures are a purpose, the use of triangular Function to make the product upside down to do. We can see, learn how triangular function is how important ah! So as for a variety of special structure, are people come up with, you can give full play to your imagination, no matter what kind of structure can go casually think Well, go to the bold design, we might have a new invention, but after the design, we must verify the relationship between the lower trigonometric function, is the actual simulation of the mold under the mold opening and closing action, and consider the next injection Will there be a problem and so on.
Having said that, we divided the points. The next is the mold structure of the ranking, these contents are in advance to sort out the clue, according to the actual situation of the product, the choice of different types of mold structure, for example, two mold, three plate mold, hot runner, IMD, Two-color, stacked and so on. All the mold structure type is to be able to achieve a good product quality and service. In the selection of mold, we have to fully consider the four points that have just mentioned the note.
Select the mold we have to consider the mold of the mosaic, the principle of mosaic is to simplify processing, saving materials, conducive to product molding, such as exhaust and so on. You think there is a particularly thin place on the mold, must be a separate mosaic out, easy to replace the future. In the mosaic of the time to fully consider the strength of inserts, processing, and the future design of the water. After the mosaic is finished, it is necessary to add standard parts. Plus the principle of standard parts is the first focus on the local, as far as possible layout balance symmetry. Generally have to first add the mandrel, plus the top pole must consider the arrangement of waterways. Under normal circumstances, give priority to the arrangement of the mandrel, and then generally design the waterway, and then adjust the water stroke according to the actual situation, so that the two balance. Plus the top of the principle is to hold the force of the place, the other to be added to the product of the Leng, Taiwan, edge and other strength structure is better place, so as not to top white or top imbalance. Drainage of the principle is to add the top of the principle, because in general, the product is a strong place where the product is hot, need to strengthen the cooling of the site, the contradiction needs to be adjusted. As for the end is the top of the rod or with the top block or push plate, you need a specific analysis of the specific issues. This is to combine the structural characteristics of the product to analyze, such as the product easy to stick before the mold, we must consider whether or not after the mold plus buckle, or die plus top, these are natural things, but many friends will not want a comprehensive What is the reason, that is because there is no analysis of the product structure is full, there is no practical consideration in the state of the product in the injection process. This is the key to the problem. Pole waterway finished, and the rest is that the mess of the standard parts, and everyone in the time to add as much as possible to consider the symmetry balance it wants.
After the completion of the entire mold design, be sure to do the following checks, the first is the insert of the draft analysis to see if there is no buckle of the place, followed by the mold parts of the interference check, Now the three-dimensional software has this feature, very convenient. And then is the mold open and close the mold of the simulation, and then simply as long as the mold is not too clear, it must be the actual simulation, the other is the mold parts of the machinability and mold assembly process, do not work hard to design a Clever structure, the theoretical calculation is no problem, finished processing, the results do not fit, or bad assembly.
At this point, you can congratulate you, the general process has ended. In fact, the mold design is full of contradictions. Want to design more perfect, the mold cost is high, want to design a little more, the product may be changed or the strength of the mold, the life will have an impact. So the mold design is not absolute. Just looking for that balance, you design the mold is successful. So, someone else's design structure may not be for you. As long as you follow the mold design points above, it is estimated that we can design a more reasonable mold structure.