Auto bumper mould
Auto bumper mould
Auto bumper mould is also named automobile bumper mould and car bumper mould. there are also two different kinds – front bumper mould and rear bumper mould.
MINGYU mould has more than 20 years experience on the bumper mould design and bumper mould making.
what’s auto bumper and what’s its feature?
The car bumper is one of the most important appearance parts of the car. It must have sufficient strength and rigidity. It can cushion the car in the event of a collision, protect the car body, and pursue harmony and unity with the car body shape. Light weight itself. In order to achieve this goal, the front bumper body of the car is currently made of plastic, commonly known as plastic bumper molding by injection mold,
The front bumper of the car is shaped like a saddle. Generally,the material was PP+EPDM-T20, and the shrinkage rate was 0.95%. Among them, the PP also named polypropylene is the main material of the auto bumper. The EPDM rubber can improve the elasticity of the bumper cover, while the T20 refers to the addition of 20% talcum powder to the material, which can improve The rigidity of the auto bumper cover.
in summary, we can find that the sturctur of auto bumper mould is complex, mould size will be big, the wall thickness is relatively thin.
2. Mould design and structure
Parting surface
Usually,for the front auto bumper mould, we will design with inner parting surface technology. The advantage is that the parting line is hidden on the non-appearing surface of the bumper, and can not be seen after assembly on the car, and does not affect the appearance.
However, this technology is more complicated and structurally difficult than the external type bumper, and the technical risk is also high. The mold cost and mold price are also higher than the external type bumper, but because of the beautiful appearance, widely used in the middle and high-end cars.
Auto bumper mould steel
Generally, about the front bumper mold making, molding part and the template are integrated, and the template material is pre-hardened mold steel P20 or 718
Feeding system of auto bumper mould
The mold feeding system adopts an integral hot runner system, and its advantages include convenient assembly and disassembly, low processing precision, no risk of leakage, accurate assembly accuracy, and no need for repeated disassembly and assembly and lower maintenance and repair costs.
temperature control system design of bumper mould
The design of the temperature control system of the front bumper body injection mold has a great influence on the molding cycle of the mold and the product quality. The mold temperature control system takes the form of “straight-flow cooling water pipe + inclined cooling water pipe + cooling water well”.
The design points of the cooling water channel of this mold are as follows:
1. The dynamic mold structure is more complicated, and the heat is more concentrated. It is important to cool, but the cooling water channel must be at least 8mm away from the push rod, straight top and inclined top hole.
2. The distance between the waterways is 50~60mm, and the waterway is 20~25mm away from the cavity surface.
3. If the cooling channel can be made into a straight hole, do not make a slant hole. The inclined hole with a slope of less than 3 degrees is directly changed to a straight hole.
4. The length of the cooling water channel can not be too different to ensure that the mold temperature is roughly equal.
Ejecting system
Auto bumpers are large thin-walled parts, and the demoulding must be smooth and safe. The middle position of the mold adopts a straight top and a ejector pin, and the thimble has a diameter of 12 mm. Because the contact area is small and difficult to return, it is easy to cause the thimble to collide with the fixed cavity surface.