Design of gating system and inner runner in casting process

Gating system design:

1.Design of sprue cup

(1) Sprue cup shape

The shape of sprue cup can be divided into two types: funnel and pool. The funnel shape is simple and the slag retaining effect is small. It is mainly used for small iron castings and steel castings. The pool gate cup has a good slag retaining effect and is mainly used for medium and large iron castings.

(2) Sprue cup function

A it is convenient to bear the liquid metal flow from the ladle and lead it into the sprue to prevent overflow due to over pouring.

B. avoid the direct flow of strand to the sprue and reduce the impact of liquid flow on the mold.

C has a certain slag retaining effect.

D when the height of the low pressure head of the sand box is not enough, the static pressure head of the metal liquid can be increased.

2.Design of sprue

(1) Sprue shape

In general, the sprue is a conical shape with large upper and small lower or large upper and small lower. The sprue nest is designed at the bottom to buffer the impact of liquid flow. It is connected with sprue cup, cross sprue and sprue socket with fillet.

(2) Sprue action

A guide the metal down from the sprue cup into other components of the gating system or directly into the cavity.

B provide enough pressure head.

3.Runner design

(1) Runner shape

There are three kinds of runner: trapezoid, dome trapezoid and circle. The first two kinds of iron castings are used.

(2) Runner action

A distribution flow.

B slag stopping. It is necessary to make full use of the slag blocking function of the cross sprue, design the flow blocking sections of various structures and meet the structural requirements of different castings.

Design of internal sprue

(1) Sprue shape

For sand cast iron castings, flat trapezoid is often used. For the sand coated ductile iron parts of the iron mold, the round shape is often used.

(2) Function of internal sprue

The function of the sprue is to guide the metal into the cavity at night.