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Injection mold design is good, please remember in the 17th National Congress (2)

Injection mold design is good, please remember in the 17th National Congress (2)

The mold industry is a basic industry in the manufacturing industry and the basis for the transformation of technological achievements. At the same time, it is an important field of high-tech industries. It is called the magnetic industryin the industrialized countries such as Europe and the United States.

The American industry believes that "the mold industry is the cornerstone of American industry"; Germany considers it to be a "key industry" in all industries; the Japan Die Association also believes that "the mold is the driving force for the prosperity and prosperity of society" and "the whole industrial development." The secret of "the driving force behind entering a wealthy society."

X. Logo

The product identification is generally set on the flat surface of the product, and the convex form is adopted. The selection of the normal direction and the surface of the mold opening direction may be set to mark, which can avoid the strain.

XI, precision of injection molded parts

Due to the non-uniformity and uncertainty of shrinkage during injection molding, the precision of injection molded parts is significantly lower than that of metal parts. The dimensional tolerances of mechanical parts cannot be simply applied. The appropriate tolerance requirements should be selected according to the standard. China also released GB/ in 1993. T14486-93 "Dimensional Tolerance of Molded Plastic Parts for Engineering Plastics", the designer can determine the dimensional tolerance of the parts according to the requirements of the standard according to the plastic raw materials used and the requirements for the use of the parts. At the same time, according to the comprehensive strength of the factory, the design accuracy of the products of the peers to determine the appropriate design tolerance accuracy.

Twelve, deformation of injection molded parts

Improve the rigidity of the injection molded product structure and reduce deformation. Try to avoid the flat structure and set the flange and the concave and convex structure reasonably. Set reasonable reinforcement bars.

Thirteen, the buckle

1. The buckle device is designed to be shared by a plurality of buckles at the same time, so that the whole device can not be operated due to the damage of the individual buckles, thereby increasing the service life thereof, and then multi-test filtering and rounding to increase the strength.

2. The tolerance of the relevant dimensions of the buckle is very strict. If the position of the buckle is too much, the buckle will be damaged. On the contrary, if the position of the buckle is too small, the assembly position is difficult to control or the combination part is too loose. The solution is to reserve a way to change the mold and easily add glue.

14. Welding (hot plate welding, ultrasonic welding, vibration welding)

1, using welding, can improve the joint strength.

2, using welding, can simplify product design.

Fifteen, reasonable consideration of the contradiction between process and product performance

1 When designing injection molding products, the contradiction between product appearance, performance and process must be considered. Sometimes some of the craftsmanship is sacrificed to get a good appearance or performance.

2 structural design can not avoid injection defects, as far as possible let the defects occur in the hidden parts of the product.

Sixteen, the relationship between the screw column aperture and the diameter of the self-tapping screw

Self-tapping screw column aperture

M21.7mm

M2.32.0mm

M2.62.2mm

M32.5mm

Seventeen, BOSS design principles:

1. The pillars should not be used alone. They should be connected to the outer wall as much as possible or used together with the ribs. The purpose is to strengthen the strength of the pillars and make the rubber flow more smoothly.

2. The height of the pillars is generally not more than two and a half times the diameter of the pillars. Excessively high pillars can cause plastic parts to become trapped when they are formed (the pores will cause pores, burnt, insufficient filling, etc.).

3. If the height of the pillar exceeds two and a half times the diameter of the pillar, especially the pillar away from the outer wall, the method of strengthening the strength of the pillar is to use the reinforcing rib.

4. The shape of BOSS is mainly circular, while other shapes are difficult to process.

5. The position of the BOSS should not be too close to the corner or the outer side wall, and should be kept at a distance from the outer wall of the product.

6), around the BOSS can be used to remove part of the meat thickness (ie open crater) to prevent shrinkage and subsidence.

7), BOSS dialing angle: usually take 0.5 ° outside, take 0.5 ° or 1 inside.

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