CN104646635A

CN104646635A - Casting method for valve body of expansion valve

Info

Publication number: CN104646635A
Application number: CN201510045782.5A
Authority: CN
Inventors: 夏平桂
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-01-29
Filing date: 2015-01-29
Publication date: 2015-05-27

Abstract

The invention provides a casting method for a valve body of an expansion valve. An insulating riser is installed at the part of a central flange of a sand core, blind risers are installed at the tail of the valve body of the sand core and the part of a drain hole of the valve body, the insulating riser is used for feeding on the central flange, the insulating riser of the central flange is used for feeding at the part of a valve belly by adopting the form of a feeding rib, and the blind risers are used for feeding at the tail of the valve body and the part of the drain hole of the valve body; the lower parts of a lower molding pit external mold real sample and an inner cavity sand core assembly are scraped to be planes by using a shaft rod scraper, and an upper molding cover core and a riser are calculated based on rod-shaped parts and divided into an upper layer and a lower layer. The casting technology for the main valve body of the expansion valve, provided by the invention, adopts a combination of the inner layer and the outer layer of open and blind risers with an external chill quenching process, so that the problems of shrinkage cavity and shrinkage porosity of a thin-walled steel casting in a production process are effectively eliminated, namely a complete set of inner quality control system is formed by the process.

Description

A kind of valve body casting method of expansion valve

Technical field

The present invention relates to a kind of valve body casting method of expansion valve, belong to field of mechanical technique.

Background technology

Due in hydroelectric facility for the needs of the key and particularity of ZG20Mn carbon steel expansion valve in environment for use closing key control, also relatively high to the requirement of its main valve body inherent quality, but, by the limitation of existing Casting Technology, current China is domestic does not also have a set of unified casting technique in casting field, namely current casting technique produce casting expansion valve main valve body effectively cannot ensure the requirement that its inherent quality can reach reliable and stable, this just brings hidden danger to the safe and stable operation of the relevant hydroelectric facility installing and using this expansion valve virtually.

Summary of the invention

The invention provides a kind of valve body casting method of expansion valve, described technique defines the Control of Internal Quality system of the unified standard of complete set, thus reaches and effectively control the reliable and stable object of expansion valve main valve body inherent quality according to described technological requirement.

For realizing above object, the technical scheme that the present invention will provide is: a kind of valve body casting method of expansion valve, it is characterized in that: in core, insulated feeder is installed at flange position, at valve body afterbody and the valve body mudhole position installation blind riser of core, middle flange uses insulated feeder feeding, valve tripe position adopts feeding muscle form to carry out feeding by the insulated feeder of middle flange, and valve body afterbody and valve body mudhole position use blind riser feeding; Mo(u)ld bottom half melt pit external mold full pattern, inner chamber core core assembly, out-of-plane scraped by bottom axle thick stick scraper plate, mo(u)ld top half cover core, rising head calculates by rod-like element, is divided into two-layer up and down, be positioned at 1.3 times of the upper strata open riser modulus heat-obtaining joint in outside, be positioned at 1.1 times of lower floor's blind riser modulus heat-obtaining joint of inner side, wherein, two place's open risers of corresponding axis hole all require to calculate modulus by the thermal center placed after subsidy; Two place's open risers of corresponding axis hole all divide into subsidy, and the thickness of its subsidy must meet the molten steel feeding demand of axle bottom thermal center; All place every sand external chill between the bottom surface of every adjacent two blind risers, for blocking the MOLTEN STEEL FLOW between axis hole and blind riser, require to place 100mm respectively at the thermal center inner face of axis hole bottom and corresponding axis hole bottom thick in sand external chill, simultaneously, for sintering appears in the molding sand preventing correspondence to be positioned at bull nose, require all to place 30mm hard chromium iron ore at each bull nose place; In addition, require to place the thick external chill of 60mm at corresponding valve body lateral wall, and require the external chill placed be placed on axis hole bottom formed around the valve body lateral wall loop configuration of a week after seamless splicing every sand external chill; For effectively preventing foundry goods from occurring centre porosity phenomenon, requiring to manufacture feeding a casting end between two-layer rising head, requiring it to meet to be not less than the pressure testing requirement of 40Kgf/cm2.

The valve body casting method of this expansion valve that the present invention relates to, expansion valve main valve body casting technique adopts inside and outside two-layer bright, blind riser and external chill chilling technology combine, the shrinkage cavity in process of production of effective elimination Thin-Section Steel Castings, shrinkage porosite problem, namely described technique defines the Control of Internal Quality system of complete set, thus it is obstructed to efficiently solve the feeding a casting passage that expansion valve main valve body causes because of structure problem, the difficult problem that upper and lower flange position feeding a casting can not take into account, this has not only ensured the reliable and stable of expansion valve main valve body inherent quality, but also significantly reduce when heat treatment link is reprocessed and cleared up to foundry goods and need repeatedly to repair brought cost burden, and then be that the enterprise applying this technique brings good economic well-being of workers and staff.

Detailed description of the invention

A kind of valve body casting method of expansion valve, in core, insulated feeder is installed at flange position, at valve body afterbody and the valve body mudhole position installation blind riser of core, middle flange uses insulated feeder feeding, valve tripe position adopts feeding muscle form to carry out feeding by the insulated feeder of middle flange, and valve body afterbody and valve body mudhole position use blind riser feeding; Mo(u)ld bottom half melt pit external mold full pattern, inner chamber core core assembly, out-of-plane scraped by bottom axle thick stick scraper plate, mo(u)ld top half cover core, rising head calculates by rod-like element, is divided into two-layer up and down, be positioned at 1.3 times of the upper strata open riser modulus heat-obtaining joint in outside, be positioned at 1.1 times of lower floor's blind riser modulus heat-obtaining joint of inner side, wherein, two place's open risers of corresponding axis hole all require to calculate modulus by the thermal center placed after subsidy; Two place's open risers of corresponding axis hole all divide into subsidy, and the thickness of its subsidy must meet the molten steel feeding demand of axle bottom thermal center; All place every sand external chill between the bottom surface of every adjacent two blind risers, thus effectively prevent the molten steel between blind riser from series winding phenomenon occurring; For blocking the MOLTEN STEEL FLOW between axis hole and blind riser, require to place 100mm respectively at the thermal center inner face of axis hole bottom and corresponding axis hole bottom thick in sand external chill, meanwhile, for sintering appears in the molding sand preventing correspondence to be positioned at bull nose, require all to place 30mm hard chromium iron ore at each bull nose place; In addition, require to place the thick external chill of 60mm at corresponding valve body lateral wall, and require the external chill placed be placed on axis hole bottom formed around the valve body lateral wall loop configuration of a week after seamless splicing every sand external chill; For effectively preventing foundry goods from occurring centre porosity phenomenon, requiring to manufacture feeding a casting end between two-layer rising head, requiring it to meet to be not less than the pressure testing requirement of 40Kgf/cm2.

Detailed description of the invention of the present invention does not form the restriction to the application's scope; within every spirit in the present invention's design and principle, any amendment that one of skill in the art can make, equivalent to replace and improvement etc. all should be included within protection scope of the present invention.

Claims

1. the valve body casting method of an expansion valve, it is characterized in that: in core, insulated feeder is installed at flange position, at valve body afterbody and the valve body mudhole position installation blind riser of core, middle flange uses insulated feeder feeding, valve tripe position adopts feeding muscle form to carry out feeding by the insulated feeder of middle flange, and valve body afterbody and valve body mudhole position use blind riser feeding; Mo(u)ld bottom half melt pit external mold full pattern, inner chamber core core assembly, out-of-plane scraped by bottom axle thick stick scraper plate, mo(u)ld top half cover core, rising head calculates by rod-like element, is divided into two-layer up and down, be positioned at 1.3 times of the upper strata open riser modulus heat-obtaining joint in outside, be positioned at 1.1 times of lower floor's blind riser modulus heat-obtaining joint of inner side, wherein, two place's open risers of corresponding axis hole all require to calculate modulus by the thermal center placed after subsidy; Two place's open risers of corresponding axis hole all divide into subsidy, and the thickness of its subsidy must meet the molten steel feeding demand of axle bottom thermal center; All place every sand external chill between the bottom surface of every adjacent two blind risers, for blocking the MOLTEN STEEL FLOW between axis hole and blind riser, require to place 100mm respectively at the thermal center inner face of axis hole bottom and corresponding axis hole bottom thick in sand external chill, simultaneously, for sintering appears in the molding sand preventing correspondence to be positioned at bull nose, require all to place 30mm hard chromium iron ore at each bull nose place; In addition, require to place the thick external chill of 60mm at corresponding valve body lateral wall, and require the external chill placed be placed on axis hole bottom formed around the valve body lateral wall loop configuration of a week after seamless splicing every sand external chill; For effectively preventing foundry goods from occurring centre porosity phenomenon, requiring to manufacture feeding a casting end between two-layer rising head, requiring it to meet to be not less than the pressure testing requirement of 40Kgf/cm2.