Analysis of Automobile Injection Moulds

In the development of the automobile industry, the demand for plastic parts is increasing day by day, because the application of plastic parts in the construction of automobiles is very high, that is to say, the quality of plastic parts has a huge role in promoting the development and construction of the automobile field, which requires plastic parts. Parts need quality assurance in production, and it is the mold that determines the quality of plastic parts. There are not a few cases where the plastic parts produced cause losses to various fields during the application process due to the mold. It is very helpful for my country's economic development to carry out research on molds for the purpose of improving the quality and efficiency of plastic parts.

We all know that automobiles are very dependent on the application of plastic parts. At the same time, automobile products are constantly updated. Only by mastering the key and difficult points of Plastic Automotive Dashboard Injection Molding can mold production meet the development needs of the automotive industry.

The basics of injection mold design

1 Plastic product design is the focus

Plastic products are definitely a key link in the design of Custom Injection Mold. The design of plastic products requires nothing more than to simplify the model of plastic products as much as possible, especially the design of concave and undulating products. It is best not to appear in the design of plastic products.

The requirement for simplicity in the design of plastic products is a general direction, because there are many small links in the design of plastic products. Simplified design is a requirement for each refinement link of plastic products. The basic requirements of the link, such as the design of the thickness of the injection mold, should make the wall thickness of the mold as uniform as possible while evolving, and avoid inappropriate glue positions with uneven thickness. The stiffness and hardness also need to meet the standards, which is a key link to ensure the quality of plastic parts.

2 Classification of plastic products in structural design

The inner and outer sides of the plastic product must have a demoulding slope that meets the demoulding standard, which is more conducive to demoulding. In order to make the appearance smooth and the demoulding is not hindered by friction, the plastic products should be as streamlined and smooth as possible in terms of radian and texture. Plastic products have sharp corners, and these corners are rounded. For the radian problem, in the peripheral corners of the inner and outer sides of the plastic product, the radian tension should be larger, which is very necessary.

The basic requirements of a forming mold for parts

The strength and hardness must reach a certain standard, otherwise it will not be able to withstand friction, which will affect the construction quality. The minimum hardness requirement should not be lower than HRC35, and the hardness of very few special requirements should be above 50~52HRC. The surface is shiny and can be achieved by polishing. In addition, the cavity part needs to be polished. The sample of the product cannot deviate from the product requirements. Then, the management and construction technology can improve the production efficiency and save the cost.

1. Clear cavity number

The method of determining the number of cavities can use all the injection machines, and then confirm the number of them by the amount of injection and the rated clamping force of the injection machine. In the process of the number of cavities, other factors need to be combined, such as: molding process, precision and maintenance, and economy.

2. Identify the fractal line and the mold parting surface

The determination method of the fractal line can be determined according to the shape of the part. The function of the fractal line is to divide the product into two parts, and the dividing line exists the same. The two parts divided into one part are formed in the fixed mold, and the other part is formed by the movable mold. To obtain the parting surface of the mold, the fractal line can be used, and the parting surface of the mold can be determined by scanning the fractal line around the two molds.

3. Precautions for parting surface design

The step parting surface generally needs to have an insertion inclination angle of 3 to 5 degrees when facing the step parting surface, and the angle cannot be lower than 1.5 degrees. Sometimes multiple step surfaces appear in a parting surface at the same time. In this case, the same angle is used to act on the angle A, which makes the processing easier and more convenient.

There is one part of the parting surface of the mold that needs special attention, that is, to ensure that each same surface has a sealing distance, and at the same time to ensure the effectiveness of this distance, so that the plastic melt does not easily flow out during the injection process, and the sealing distance This name corresponds to this effect, which can block the material. In the process of creating the parting surface, if there is a parting surface with a large difference in height such as a curved surface, an inclined surface, and a step, whether it is one or more, a reference plane must be set for it, which can facilitate processing and measurement.

4. Basic principles of parting surface design

The molding plastic needs to be retained on the half mold after the mold is opened. Of course, this is under the premise of the ejection mechanism. Generally, the ejection mechanism half mold is a moving mold, and only the ejection mechanism half mold that appears in a few special cases is on the die.

Some plastic products will come with metal inserts. Since the inserts do not have the function of shrink wrapping the punch, the shape cavity is usually designed on the side of the movable mold. Once this happens, demolding becomes very difficult. If the coaxiality structure is inside the movable mold or the fixed mold, if it is formed on both sides of the two molds, it is difficult to ensure the accuracy of the coaxiality. This situation is mostly due to manufacturing errors and assembly errors. caused.

There are certain requirements for the locking of the mold, which must be satisfied. In order to meet this requirement, plastic products are generally placed at the clamping part of the ground motion quantitative mold. For lateral fractal surfaces. This can greatly reduce the locking force. In addition, the parting surface sometimes has a curved surface. When this phenomenon occurs, a positioning mechanism must be added, and the selection of the parting surface should not affect the shape of the Multi-Cavity Mold plastic product as much as possible. If the plastic product has diamond lines and tangents in its shape, it is not suitable for the selection of parting surfaces.

The parting surface must be selected to be relatively smooth and without obvious sharp corners, so that the segmentation will not affect the quality and shape. Although it is not absolute, the probability of occurrence is still high. Be sure to arrange the size and quantity of the inner mold inserts reasonably.