In design practice, different customers have different requirements for cooling system design. Designer first considers customer's requirements, then combines mold size, structure and actual situation to comprehensively design.
Automotive injection mold cooling systems usually have three types: vertical cooling water channels, inclined cooling water channels and well-spaced cooling water channels. Vertical cooling channel means that cooling channel is perpendicular to one of outer surfaces of mold; inclined cooling channel is not perpendicular to any outer surface of mold; diameter of water well in split cooling channel is significantly larger than diameter of other water pipes, and a diaphragm is added in the middle to divide flow.
In order to improve cooling effect of automobile injection molds, above three cooling methods are often used in combination. In injection molds for medium and large automobiles, there are usually two types of combinations. The first combination is "vertical cooling channel + inclined cooling channel + well partition cooling channel". This combination is often used in injection mold cooling system of automobile front bumper; second combination is "vertical cooling water channel + well partition cooling channel + inclined cooling water channel", this combination is often used in fixed mold cooling system of automobile rear bumper injection molds.
Difference between two combined forms of automobile injection mold cooling system is mainly that focus is different, so cooling effect is also different. The first form "vertical cooling channel + inclined cooling channel + well partitioned cooling channel", vertical cooling channel is preferred, followed by inclined cooling channel, water well partitioned cooling channel is used as a last resort. Advantages of this form are uniform cooling of product, short molding cycle and high product quality. It is suitable for injection molds with high requirements and high appearance performance requirements, such as automobile front and rear bumpers, automobile upper and lower instrument panel bodies, automobile left and right door panels. Disadvantage is that processing cost is high; Second form "vertical cooling water channel + well partition cooling water channel + inclined cooling water channel", vertical cooling water channel is preferred, followed by well partition cooling water channel, inclined cooling water channel is not used as much as possible. Advantage of this form is low processing cost, convenient and quick processing; disadvantage is that too many water wells on mold reduce strength of mold, cooling effect is also worse than that of the first form. Design of distance between cooling water pipe and surface of cavity, distance between cooling water pipes is shown in Figure 1.

 

（A). Arrangement relationship of water transportation 2d≤a≤3d; 3d≤b≤4d

 

(B). Distance of water transport on parting surface 1.5d≤a≤2.5d; b=15~20mm

 

(C) Distance between well on parting surface 10mm≤L≤20mm; Y=15~20mm
Figure 1 Distance between cooling water pipe and cavity surface and distance between cooling water pipes
According to needs of different customers, reasonable design of cooling water channel of automobile injection mold plays a vital role in production efficiency and cooling efficiency of mold.