In injection mold, structure that ensures that movable parts move according to established trajectory is called guiding system; structure that ensures relative position accuracy between front and rear molds and between moving parts is called positioning system. See Fig.

1. Front and rear molds should be opened and closed repeatedly;
2. High mold precision requirements;
3. Bear high pressure in production process;
4. Bear high temperature during production process;
5. Mold life requirements are high.

1. Guide post guide bush
2. Cone surface positioning mechanism
3. Guiding and positioning mechanism of lateral core-pulling mechanism.

1. To guide;
2. Positioning;
3. Bear lateral pressure;
4. Support weight of mold.

 

1) Shape.
2) Materials and heat treatment:
3) Tolerance and fit:
Guide post fixing H7/k6,
Match between guide post and guide sleeve is H7/f7.

(1) There is a barrel;
(2) Mouth is eccentric;
(3) There are many thimbles less than 2mm;
(4) There are more thimbles on one side and less on the other.

(1) For mold base below 4040, use 2 middle brackets, diameter is equal to diameter of back needle or 5mm larger than diameter of back needle;
(2) For mold base above 4040, 4 middle brackets are used, and diameter is equal to diameter of back needle.
(3) Location: see picture below

 

 

1. Side locking position is an auxiliary positioning mechanism for guide post and guide sleeve, which is mostly used for large-scale (over 400MM wide), deep cavity and plastic parts with high precision requirements. Installed on four sides of mold.
2. Pipe position is divided into cone surface positioning between A and B plates and inner mold pipe position. Function and use of cone positioning between A and B plates is same as side lock, but it is installed between A and B plates. Inner mold tube is located on four corners of mold core and is integrated with mold core, as shown in figure.

(1) Guide positioning of lateral core-pulling mechanism itself;
(2) Positioning between lateral core pulling mechanism and core.
Note: Precautions for designing and manufacturing precision molds:
1. Advanced processing equipment and processing technology;
2. High-level mold design engineers and mold masters;
3. Mold must have a good guiding and positioning mechanism;
4. Good cooling system;
5. Reasonable gating system;
6. Correctly coordinated mold action;
7. High-quality mold steel;
8. Good exhaust system.