THIẾT TRÌNH THIẾT KẾ CHẾ TẠO KHUÔN MẪU ĐỦ 25 BÀI_16_EN

HOW TO GET OUT PRODUCTS MOULD1.Nguoi workers will take the product, check the product and tails cut glue after each injection cycle 3.With push system product-This is most often used...

HCMC UNIVERSITY OF TECHNOLOGY AND

Teacher Instruction: TRẦN MINH THẾ UYÊN Students Perform: NGUYỄN HƯỚNG DƯƠNG

CONTENTS PRESENTATIO

N

CONTENTS PRESENTATIO

1 HOW TO GET OUT PRODUCTS MOULD

1.Nguoi workers will

take the product,

check the product and

tails cut glue after

each injection cycle

3.With push system

product-This is most often used

2 propulsion system

a Mission :

When the mold opens, the remaining adhesive on the cavity due to the suction of a vacuum and the product tends to shrink after the cooling system should be pushed to push the product out

b Technical requirement :

 Simple.

 The hardness of about 40 ÷ 45 Plunger HRC, are processed accurately and mounted under the system axis.

 Impact speed up the rapid, simultaneous multiple effects for products where there is large width (faint company

 There are about push and thrust appropriate to

push the product.

 Can take the product out easily and does not affect the shape of the product, the product's aesthetics.

 Propulsion system must reside on the mobile site (site 2 sheets).

c General principles:

 After finishing the plastic filling cavity and the

cooling process, the presses will open the mold and push the axis of presses (ejector rod) will

push the two plates push (ejector plate) and

push through detailed real push Is out.

 In the process of pushing the push plate made of

molded springs back When the compressor shaft pushed back the original position, the force on the plate is no longer pushed, this time compression spring force will push back plate original position, with the guidance of the recovery key.

d The propulsion system used:

 Systems using Plunger

Materials commonly used are T8A or T10A, than 50HRC hardened and rough surfaces require 0.8 microns; fasten the H8 / f8

System push and push the latch shape

often used

System push and push the latch shape

often used

There are 3 popular feedback system:

- Using closed late :

- Using Plunger is also closing in

- Using springs to recover

 Tongue thrust propulsion systems:

Tongue thrust used to push these details are thin-walled and complex shapes for use as round pegs push for thin-walled details easily make detailed sunk in

Using thruster propulsion system

Pipe push to push the more rounded swing Using thruster propulsion system include key is fixed,

is tasked portable navigation tube slide pushed the plates push translational impact

System uses push-off plate

Used to push the details of the form cylindrical or rectangular thin-wall thickness.

Pneumatic propulsion system

For products with deep cavity such as

buckets, pots, because when the cold, the vacuum in the mold cavity and core are

so large, the product is difficult to escape the mold

f Control propulsion system:

Add a key accelerator for push

- Use a rack gear mechanism to accelerate further push latch

- The system will help speed acceleration for faster bulk products mold

 Acceleration further push plate on

(double speed acceleration)

Similar systems have accelerated push for

a push pin differs only system will control

rack in the upper thrust plate

 Plates can push lever

Push-plate system of this system will be added to increase the height lever to one side to help push products fall out of the mold with ease

 Double Stroller

Applications for complex products, the need to promote the use sequential dual propulsion system

3 CALCULATION EXAMPLE SYSTEM PUSH

 About push to 5 ÷ 10 mm larger than the product

height is taken from the mold after parting direction

 After the product is removed, the propulsion system must return its original position, avoiding damage Plunger cavity

 The size of the push pin depends on the size of the product, diameter greater than 3 mm right

 Designing propulsion system so as not to weaken the mold.

 These products have a long journey or have the key push small push, it should have the navigation key in the propulsion system.

b Plunger :

Products with high walls around, or have deep tendon, then the stick so firmly in the mold (core section), so

must be arranged near the company pushing this

position to be able to push the product out of the mold easy easy

The top of the key to push the theory lies flush with the cavity, but in reality, be it above or below 0.05 ÷ 0.1

mm Ideally located less than approximately 0.02 ÷ 0.04 mm

Rubber grip reduces vibration at latch springs back

when pushed propulsion system can be adjusted to fit the distance of push versus cavity company by turning this screw you up or down to change altitude

 The formula for calculating the thrust:

 The formula for calculating the plastic deformation of the product :

µs = CTE.(Tsolidification – Tejection)

Inside:

•Tsolidification: solidification temperature of the

material (° C)

•Tejection: temperature when taking the product

out of the mold (° C)

•CTE: coefficient of thermal expansion of the

plastic material (cm / ° C)

 After calculation of the company faint

necessary requirements lighten company's layout:

+ Set lower than 0.02 ÷ 0.1 mm cavity.

+ To lighten the best company is in or near the

edge of the product.

+ For flexible clamping plate is mounted after

the screws and washers to reduce vibration when the springs push the latch system

according pushed back.? + Pin diameter

typically 1 ÷ 25mm length should be

between 150 ÷ 500mm

c Calculation of spring :

Sized springs are defined standards available.

The total length of the spring compression

should not exceed 35% of the free length of the

spring.

By calculating the load of the propulsion system,

to be able to choose springs suitable hardness If too hard, it is difficult assembly, if the software is not enough elastic force.

To avoid being caught, the spring is usually

mounted with back plate, wrap around closing time and limiting friction with the latch.

d Calculate tube and eight-core push

The formula for calculating the thrust tube system faint and faint sheet:

Products propelled by thrust plates

e Calculate the recovery of silver and

key:

There are two key types in:

+ In mold automatic: after pushing the

product out of the mold is under elastic force

of the spring, the system will return to its

original state in preparation for the next