CN112238214A

CN112238214A - Die casting technology without overflow groove

Info

Publication number: CN112238214A
Application number: CN201811165854.XA
Authority: CN
Inventors: 王帮华
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-09-18
Filing date: 2018-09-18
Publication date: 2021-01-19

Abstract

The invention relates to a process method for realizing the forming process of die-casting parts in pressure casting, which is called 'non-overflow groove die-casting technology', and the invention is very important in considering the flow direction, the filling sequence and the position and the scheme of exhausting gas of controlling liquid metal when designing a die-casting die, and excessive overflow becomes unnecessary, so that no overflow groove is arranged. Thereby reducing the manufacturing cost of the die, saving two tenths of die casting alloy, eliminating the casting defect caused by the error area of the overflow groove, improving the product quality and ensuring that the new die is put into production successfully at one time.

Description

Die casting technology without overflow groove

The scheme is a technological method applied to pressure casting (also called liquid forging and extrusion for short) and flawless molding.

The casting defects of the die-casting part are mainly contained in the casting, but the casting defects also have the defects of exposed surfaces, and more shrinkage cavities and air holes exist. In order to avoid casting defects, the design of the mold is required to design an overflow groove (also called a slag collecting groove, a slag collecting bag, a slag discharging groove and a slag discharging bag) to remove dirt, transfer and supplement the casting defects. And the total volume of the overflow groove is specified to be not less than 20% of the volume of the casting (see pages 83-88 of a design manual for die casting mold published by mechanical industry Press 1981.12). Since the presence of dirt is indicated, there is no description of how to identify, separate, and direct the discharge into the overflow trough; secondly, the design of the injection opening is convenient to select only one side of the casting, and no matter the mold filling sequence, part of gas is contained in the middle of the casting and is scrapped; thirdly, the design of the exhaust gap has no direction or emphasis, and other three sides except the injection opening side can be arranged, which is also one of the reasons for containing gas.

In practice, the mold cavity is carefully purged each time before mold closing. Dirt has never been found to adhere to the castings and the overflow blocks (overflow trough formers). Since there is no dirt, the overflow launder should be eliminated, saving alloy by 20%. The pressure jet and the air discharge gap play an important role, and must be carefully considered!

The filling of the alloy liquid must be carried out after the prior process, the sequential filling is carried out, the exhaust is convenient to consider, the high-pressure alloy liquid injected into the cavity has enough energy to be directly injected to the bottom edge, the high-pressure alloy liquid can not continuously advance, the vortex is formed at the position to fill the cavity, and the full-section filling is further formed. When the casting shrinkage needs to be fed, energy is stored in the casting formed at high pressure and can be fed by itself, and the cast filled in sequence is provided with a terminal to exhaust and does not contain contained gas.

By adopting the scheme, the produced casting has no shrinkage cavity, gas defect and completeness.

Claims

1. A pressure casting technology is a technological method applied to pressure casting to realize the forming process of a die-casting part; the method is characterized in that in the die-casting die used in the design, manufacture and use, the flow direction of liquid metal is mainly considered to be controlled, the filling sequence, the position and the scheme of gas discharge are considered, and no overflow groove is arranged.

2. The die casting technology, the name of liquid forging technology, the name of extrusion technology and the like (only referring to die casting liquid metal) according to the claim 1 have the same process method as the die casting technology, and the name of the technology is still the technical invention.

3. The die casting technology according to claim 1, wherein the overflow groove is named as a slag collecting groove, a slag collecting bag, a slag discharging groove, a slag discharging bag and the like, the operation principle of the overflow groove is the same as that of the overflow groove, and the invention belongs to the invention when the overflow groove is replaced by the slag collecting groove, the slag discharging bag, the slag discharging groove, the slag discharging bag and the like.