The key points of die casting die design

R-C (1)

1.The die set

a. The outer surface shall be bright and smooth. Add 2 holes to the front and rear die frames, and pay attention to the position without inserts to prevent the parts from falling out.

b.A.B plate die frame with 0.1-0.15, and add a flying water baffle to prevent aluminum slag flying out of harm.

c. In order to prevent deformation of the template, at least two support columns should be made, one on the shunting cone and the other on the shunting cone. Be careful not to interfere with other parts.

d. Add 2-4 roots of middle brackets and middle brackets to the mold. The middle brackets should be made with a limit.

e. Mold bottom plate should be open to facilitate heat dissipation.

f. The four corners of the mold should be cut to prevent the Green column from hitting during installation.

g. The surface of the inner hole of the positioning ring shall be nitrified after inner round grinding, and polished along the direction of the die.

h. The length from the bottom of the cooling ring on the surface of the positioning ring to the surface of the shunting cone is generally equal to the thickness of the cake. There are two ways to fix the cooling ring: welding and heating.

i. The shunting cone must be cooled by carrying water 25-30mm away from the surface of the shunting cone.

j. The four guide post holes of the mold frame shall be made into skid groove, with a depth of 8-10mm.

k. Die frame must be tempered and conditioned, it is best to forge the die frame.

l. In order to easily take the insert needle of the inner die, you can add a hole in the surface of the die, and then close a few headless screws, so that it is convenient to disassemble and replace the insert needle.

m. Hoisting holes at least M30 deep 45, at least 2 at the top.

n. External slingshot must be added to do spring protective sleeve, prevent spring deformation.

o. Support columns shall be added to the surface above the formwork and in contact with the ground.

2.Inner mold and insert

a. Stress removal should be done after processing and before heat treatment. General aluminum alloy quenching HRC45+/-1°C, zinc alloy quenching HRC46+/-1-1°C

b. The fitting tolerance of the inner mold: generally, it is about 0.05-0.08mm less than the mold frame, which can be easily removed and put into the mold frame with the hanging ring. Thimble fit tolerance: 0.05mm for thimble clearance greater than or equal to 8mm, 0.025mm for thimble clearance less than or equal to 6mm.

c. All the inner mold above the right Angle and acute Angle must be R0.5mm above the package. d. The excess holes on the surface of the inner mold should be closed with a one-line screw.

3.Design of runner and slag discharge system

a. The main channel of the fabric cake on the shunting cone should be within 1/3 of the circular surface area. This prevents the cold material from entering the cavity quickly before sealing the parting surface.

b. The main channel above the shunt cone should be made into a “W” shape, and the thickness of the cake should be 15-20mm.

c. Generally, the length of the main channel should be 30-35mm, and the single side should be 5-10°.

d. Generally, the cross passage is best to turn, and make more than 2 steps, to prevent cold material through the cross passage into the cavity, resulting in cold lines on the surface of the product.

e. Generally, it is best to add 2 buffers at the gate position where the cross runner enters the product outlet, so that the cold material is completely blocked out of the cavity.

f. The thimble level below the general standard mainstream should be made into a mold, and the package should be above R2.

g. The convex core on the opposite side of the main road must be avoided, and the slag bag on the opposite side of the main road is best to make garbage bag first, and then open again depending on the situation.

h. Slag bag is best to open the plane of the court, semicircle section shape, and the water inlet and exhaust groove should be separated by 1/3. Slag bag into the water should also skip.

i. Exhaust slots should be reduced and smoothly transitioned, following the rules of “3.2.1”.

j. For the convenience of processing, the gate at the junction of the DC channel and the product should step by step, so that it is not easy to drop meat during post-processing.

4.Cooling system

a. The shunting cone must be cooled and transported to prevent premature cracking of the shunting cone.

b. The gate sleeve is used as a cooling ring for cooling. There are two ways to fix the cooling ring: welding and hot pressing.

c. The cooling of the inner mold shall ensure the following data. The diameter of the water pipe is generally 8-10mm. Water from the lowest surface of the product height: aluminum alloy: 25-30mm. Zinc alloy: 15-20mm.

d. If the inner mold must be carried out of the mold frame, the waterproof ring with high temperature and high pressure resistance must be used.

5.Core-pulling mechanism

a. The slider must be made at least one hanging hole on the upper and lower sides for easy disassembly and assembly.

b. The bottom of the slider should be cut into the trough, and the wear-resistant strip should be made into 2 pieces 8-12mm higher than the bottom die surface to facilitate the cleaning of aluminum slag during production.

c. The strip of the slider should be made into a wear-resistant groove, and the core pulling direction is 45°

d. Sliding mechanism should be flexible, smooth movement, matching clearance 0.08-0.12mm.

e. The sliding block and the locking block should be compressed after the die closing, and the contact area should not be less than two-thirds, and there should be certain prestress.

In the design of the pressing die, the following methods and design procedures should be generally followed:

(1) Study and analyze product drawings, understand the use, use status and appearance requirements of plastic parts, especially the dimensional accuracy requirements of key parts, as well as the plastic varieties used and the performance of forming process.

(2) According to the production batch of plastic parts, determine the type of pressing die. Such as large plastic parts, the selection of fixed pressing structure; Plastic parts small batch, the use of mobile pressing mold structure.

(3) Conceive several mold structure scheme for comparison, the use of easy to manufacture, easy to operate, can ensure the quality of molding parts of the mold structure. According to the size, shape and the number of embedded parts and precision requirements, determine the use of pressing die or transfer die, the use of closed pressing die or semi-closed pressing die structure.

(4) Select the parting surface. In the selection of the parting surface, the surface roughness requirements of the finer surface, must not be used as the parting surface.

(5) The design of convex and concave die, to carry out the necessary size calculation, marking tolerance should be reasonable.

(6) determine the mold sleeve size. According to the design of punch and die to determine the mold cover and fixed plate size, strength should be appropriate.

(7) determine the guide form, design its size and installation method.

(8) determine the upper and lower mold positioning mode and structure form and size.

(9) Calculate the electric power required by the pressing mold, and design the heating element.

(10) The design of die unloading and parts unloading device should strive to balance the force.