Automobile injection molds generally have domestic molds and export molds. Generally, domestic molds have lower requirements and lower prices, export molds have high requirements and high prices. Therefore, requirements for mold design and manufacturing are very high. Compared with domestic molds, export molds are mainly more demanding, more complicated, and detailed design requirements are high. Whether it is appearance and strength of mold, or standard parts, hot runner, steel of mold is much stricter than domestic mold. This article will take some complex typical cases of exported automobile injection molds to discuss key points of European and American automobile injection mold design.

 

In mold structure design, some types are different from conventional mold structures, such as stack molds, twisted tooth molds, arc core pulls, terminal molds, low pressure injection molding, IMD molds, etc.
Among them, twisting mold can be divided into: front mold extraction, rear mold extraction, row extraction, etc.;
According to mold structure, it can be divided into: cylinder gear rack structure, hydraulic motor with sprocket structure, servo motor with sprocket structure, front and rear mold opening rack with slider structure, rifle screw with gear structure, etc.;
According to type of thread withdrawal, it can be divided into: automatic thread withdrawal structure of braces, elastic plate + spring automatic thread withdrawal structure, product fixed automatic thread withdrawal structure (thread inserts rotate, product rises and ejects simultaneously)
Today I will share with you a set of mold structure of a hydraulic motor with sprocket core pulling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Automatic threading mechanism is divided into three types according to power transmission mode:
1) Motor drive. Motors include electric motors and hydraulic motors. Electric motors are rarely used because they rotate too fast and their movements are not stable; hydraulic motors are widely used because of their relatively slow speed, smooth movements, and safety. Almost 95% of molds that use motor drive use hydraulic motors. When using a motor drive, there must be two other accessories combined with each other, namely sprocket and chain. Motor, sprocket, and chain three most important components are indispensable to realize motor transmission. (Hydraulic motor is directly connected with gear to drive teeth)
2) Thread drive (ie, rifle nut). Screw drive uses two important combined components, a multi-head screw rod and a matching spiral sleeve, to drive gear drive. Mold structure of screw drive is the simplest, and screw drive greatly simplifies mold structure. Both screw rod and screw sleeve are imported standard parts manufactured by German HASCO company.
3) Hydraulic cylinder rack drive. It mainly uses hydraulic cylinder to drive rack, and rack drives gear to achieve work. Disadvantage of this mechanism is that hydraulic cylinder and rack will occupy a lot of space on mold, which makes overall shape of mold look a bit large, brings great inconvenience to lifting and transportation of mold. Advantages: good stability and reliability, it is the most used structure.
Summary: Any automatic threading mechanism cannot be separated from one of these three structures. If it is classified from way product is threaded out, each of above types can be divided into two forms: one is that thread core is stationary in vertical direction. When thread core starts to rotate, spring will lift push plate to push out product simultaneously; The other is that thread core always keeps reciprocating motion in vertical direction. When thread core starts to rotate, it exits backward along opposite direction of thread. When thread core completely exits effective thread of product, product is pushed out by push plate. The first type is usually used when thread length is not long, product shape or end surface must have a pattern or pattern that prevents rotation. When thread length is longer, ejection distance required for push plate is larger. The first form sometimes cannot meet requirements. At this time, second form can be considered to achieve a longer thread core pulling.