CN105689647A

CN105689647A - Casting process for outlet water valve

Info

Publication number: CN105689647A
Application number: CN201610150089.9A
Authority: CN
Inventors: 俞立华; 吴桂林
Original assignee: Fanchang Huacai Casting Co Ltd
Current assignee: Fanchang Huacai Casting Co Ltd
Priority date: 2016-03-16
Filing date: 2016-03-16
Publication date: 2016-06-22

Abstract

The invention relates to a casting process for an outlet water valve. The casting process comprises the steps that 1, a metal mold is put into a high-temperature coal furnace to be preheated for a period; 2, a refractory coating layer is formed on the surface of the metal mold and comprises, by weight, 8% of graphite powder, 20% of talcum powder, 40% of refractory clay powder, 10% of peach gum and 22% of water; 3, cast iron is fused while preheating is conducted, 4.26% of carbon is added during fusion, and after the cast iron is fully fused, the cast iron is taken out for standing for a period; 4, molten metal is poured into the mold from a sprue gate, the sprue gate is closed, and extrusion is conducted; and 5, the mold is taken out to be naturally cooled for 30-60 seconds, the mold is opened, and a casting is taken out. The working procedures of the casting process are few, the casting is good in quality and high in surface precision, and the mold used by the casting process can be used for many times.

Description

A kind of casting technique exporting water valve

Technical field

The present invention relates to water valve casting technology field, be a kind of casting technique exporting water valve in particular。

Technical background

Widely, whose system common-use words living water, fire-fighting system and industry give in, are used for controlling flow, water level etc., so the quality of water valve is most important in the field of applications in water valve。

What water valve in the market was taked is sand casting, sand casting operation is many, complicated, its casting accuracy casting out is low, of poor quality, there is pore on surface, the foundry goods of longer service life can not be produced and each chiltern casting mold can only be poured into a mould once, after the foundry goods obtained, namely casting mold damages, and productivity ratio is low。It is thus desirable to one more reasonably casting technique replaces sand casting water valve。

Summary of the invention

In order to solve the problem that above-mentioned operation is many, of poor quality, there is pore on surface and productivity ratio is low, the invention provides a kind of casting technique exporting water valve, this casting technique operation product quality few, cast is excellent, and surface accuracy is high, and the used mould of this casting technique can repeatedly use。

This invention address that the technical scheme of its technical problem includes: a kind of casting technique exporting water valve, its casting technique comprises the following steps:

Step one: first metal mold is put in high temperature coal stove and carry out the preheated one-section time；

Step 2: simultaneously melted by cast iron in preheating, adds the charcoal of 4.26% when melted, after cast iron melts completely, stands a period of time after taking-up；

Step 3: pour into mould from sprue gate by molten metal, closes cast gate, extrudes。

Step 4: take out mould and place, natural cooling 30～60 seconds, open form, take out foundry goods。

Metal mold surface scribbles flame-retardant coating layer, and the composition of this coating includes: graphite powder: 8%, Pulvis Talci: 20%, fire clay powder: 40%, Resina persicae: 10%, water: 22%；

Scheme is more specifically: metal mold puts into preheating in the coal stove of 250～350 DEG C。

Scheme is more specifically: metal mold preheating time is 40～60 minutes。

Scheme is more specifically: stood 8～10 seconds by molten metal。

The invention have the benefit that the mode that present invention employs permanent mold casting, stand when molten metal is poured into a mould, the gas in the temperature evaporated metal liquid of molten metal self can be utilized, decrease the structure of whole molten metal, when pouring into a mould again, the pore on water valve surface can be reduced, and use gravity die casting process, not only reduce the operation of water valve casting, but also the pore on water valve surface can be reduced further, improve the quality of whole water valve, so that the service life of water valve is improved。

Detailed description of the invention

Embodiments of the present invention are described in further detail:

A kind of casting technique exporting water valve, the concrete operation step of this casting technique is as follows:

(1) it is preheat in 250～350 DEG C of coal stoves that metal mold is first put into temperature, and the time is 20～30 minutes, it is possible to slow down the cooling capacity of casting mold, is conducive to the graphitizing process of cast iron。

(2) metal mold surface flame-retardant coating layer, the composition of this coating includes: graphite powder: 8%, Pulvis Talci: 20%, fire clay powder: 40%, Resina persicae: 10%, water: 22%；

(3) cast iron is melted in preheating simultaneously, when melted, add the charcoal of 4.26%, after cast iron melts completely, stand one 8～10 seconds after taking-up；

(4) molten metal is poured into mould from sprue gate, close cast gate, carry out extruded with four column press of 200 tons。

(5) take out mould natural cooling 30～60 seconds, open form, take out foundry goods, cooling be in order to

Foundry goods is enable to shape before open form without regard to the amount of contraction in metal mold very big,

It is prone to take out foundry goods。

In this description, the present invention is described with reference to its specific embodiment。It is clear, however, that various modifications may be made and conversion is without departing from the spirit and scope of the present invention, description is regarded in an illustrative, rather than a restrictive。

Claims

1. exporting a casting technique for water valve, the concrete operation step of its casting technique is as follows:

Step 2: simultaneously melted by cast iron in preheating, adds the charcoal of 4.26% when melted, after cast iron melts completely, stands after taking-up；

Step 3: pour into mould from sprue gate by molten metal, is then placed in coal stove by mould, maintains the temperature at 1300 DEG C～1370 DEG C a period of times；

Step 4: take out mould and place natural cooling 30～60 seconds, open form, take out foundry goods。

2. casting technique according to claim 1, is characterized in that, the metal mold surface put in described step one scribbles flame-retardant coating layer, the composition of this coating includes: graphite powder: 8%, Pulvis Talci: 20%, fire clay powder: 40%, Resina persicae: 10%, water: 22%。

3. casting technique as claimed in claim 1, is characterized in that, metal mold is put in the coal stove of 250～350 DEG C and preheat in described step one。

4. casting technique as claimed in claim 1 or 2, is characterized in that, is 40～60 minutes by metal mold preheating time in described step one。

5. casting technique as claimed in claim 1, is characterized in that, molten metal is stood 8～10 seconds by described step 3。