Analysis Of Injection Mould For Automobile

- Oct 11, 2017-

Core tip:In the development of automobile industry, the demand for plastic parts grow with each passing day, because the car is built on the application of plastic parts is very high, that is to say there is a huge role in promoting the quality of plastic parts for the automotive industry development, which requires the production of plastic parts in need of quality assurance, the plastic parts quality is decided to die, because the mold that makes plastic parts produced losses to all areas in the application process in a few cases, so the plastic mold production to improve the quality and efficiency of plastic parts for the purpose of study is very helpful for the economic development of China.

In the development of automobile industry, the demand for plastic parts grow with each passing day, because the car is built on the application of plastic parts is very high, that is to say there is a huge role in promoting the quality of plastic parts for the automotive industry development, which requires the plastic parts in the production need to have quality assurance, and decided to plastic parts quality is the mold, because the mold things and makes plastic parts produced losses to all areas in the application process in a few cases, so the plastic mold production to improve the quality and efficiency of plastic parts for the purpose of study is very helpful for the economic development of china.

We all know that the application of the plastic parts of automobile are very dependent, and the automobile product upgrading, only to grasp the key difficulty of plastic mold production, in order to make the mold production to meet the requirements of the development of automobile industry.

The basis of injection mold design

1.1, the design of plastic products is the key point:

Plastic products is a key link of injection mold design, the design of plastic products, it is nothing more than as much as possible so that the plastic model simplification, especially the best design do not appear in the design of the ups and downs of depression in plastic products.

Plastic products in the design of the simple requirement is a general direction, because the fine is very much part of the design of plastic product, simple design is proposed for plastic products every fine link requirements, meet the basic requirements of each link based on the requirements, such as the thickness of the plastic mould design. Must as far as possible in the evolution of the mold wall thickness is uniform, avoiding inappropriate uneven plastic bits. In stiffness and hardness also need to meet the standards, which is to protect the quality of plastic parts of a key link.

1.2 classification of plastic products in structural design:

The inner and outer sides of the plastic product should be provided with the demoulding gradient in conformity with the standard of demoulding, which is more conducive to demoulding. In order to make its appearance smooth and the mold free from friction, the plastic can be streamlined and smooth as much as possible in radians and textures. Plastic products with sharp corners, the corners are rounded, around the corner on both sides in the radian problem of plastic products, the radian of the tension should be larger, this is very necessary.

The basic requirements of a mold for parts

The strength and hardness to reach a certain standard, otherwise unable to withstand friction, will affect the construction quality, hardness is not less than the minimum HRC35, very few special requirements in hardness requirements of 50 to more than 52HRC products to make the surface luster after molding, can be achieved by polishing, also need polishing there are cavities, samples of products can not deviate from the requirements of products, and then through the management and construction technology to improve production efficiency, saving cost.

Clear cavity number

The method of determining the number of cavities can be made by using all the injection machines, and then by the amount of injection and the nominal clamping force of the injection machine, the quantity is confirmed. In the course of the number of cavity, also need to combine other factors to complete, such as: molding process, precision and maintenance and economy.

Distinguish the fractal line and the parting surface of the mold

The method of determining 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, the same as the boundary line. Divided into two parts, one is located in fixed die forming, and the other is moving die forming. In order to obtain the parting surface of the mold, the fractal line can be used, and the parting surface of the die can be determined by using the fractal line scanning around the two modes.

The method of determining 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, the same as the boundary line. Divided into two parts, one is located in fixed die forming, and the other is moving die forming. In order to obtain the parting surface of the mold, the fractal line can be used, and the parting surface of the die can be determined by using the fractal line scanning around the two modes.

Design considerations of 4.1 parting surface:

The stepped parting surface usually needs 3~5 degrees of inclination angle in the face of the parting surface, and the angle can not be less than 1.5 degrees. Sometimes, there are multiple step surfaces in a parting surface. In this case, the angle A is applied at the same angle, which makes the process easier and more convenient.

Mold surface there is a need to pay special attention to, is to protect each surface are sealed with distance, but also need to ensure the effectiveness of the distance, this can make the plastic melt in the injection process is not easy to drain, sealing distance this name is because of this effect and corresponding, can the sealing lock. In the sub surface creation process, if the parting surface or meet slant and step height difference of the surface, whether it is one or more, must be set on the reference plane, which can facilitate the processing and measurement.

Fundamentals of design of 4.2 parting surfaces:

Plastic molding need to be retained in the mold half in the mold, it is of course in the launch mechanism as the premise, generally half pushing mechanism is dynamic mode, the emergence of only a very few special cases only half mold ejecting mechanism on the fixed die.

Some plastic products will be attached to the metal insert, the insert does not have the shrink wrap punch function, shape of cavity design is usually in the moving mold, without it, after opening will make plastic products in the mold region, once this happens, the release will become very difficult. In the coaxial structure in moving die or die, if both sides of the forming of the two models, the coaxiality is difficult to ensure its accuracy, this is due to manufacturing error and assembly error caused by the.

The locking of the mold have certain requirements, the requirements must be satisfied, in order to meet the requirements of plastic products are generally placed in die at earthquake quantitative mode, choose smaller placement direction projection direction, direction projection area of the place for lateral fractal surface. This can greatly reduce the locking force, in addition, the parting surface sometimes, when this phenomenon must be on the positioning mechanism, in the selection of parting surface as far as possible do not choose an impact on the shape of the plastic parts, if plastic products in its appearance has Ling line and tangent the case, is not suitable for the selection of parting surface.

Select the parting surface, you must choose a relatively smooth and no sharp corners, so that the segmentation does not affect the quality and shape, although not absolute, but the probability is still too large. Be sure to arrange the size and quantity of the insert.