CN102218518B

CN102218518B - Method for casting butterfly valve body

Info

Publication number: CN102218518B
Application number: CN201110155828A
Authority: CN
Inventors: 范建超; 辛金福; 仝长河; 杜朝玉; 付银团; 张本政
Original assignee: HENAN YUXING CASTING CO Ltd
Current assignee: HENAN YUXING CASTING CO Ltd
Priority date: 2011-06-10
Filing date: 2011-06-10
Publication date: 2012-10-24
Anticipated expiration: 2031-06-10
Also published as: CN102218518A

Abstract

The invention relates to a method for a casting butterfly valve body, comprising the steps of: 1, manufacturing an inner core: forming an annular inner core structure for later use by utilizing a plurality of fan-shaped inner core boxes; 2, manufacturing an outer core boxes according to the method in the step 1: forming an annular outer core structure for later use by utilizing a plurality of fan-shaped outer core boxes; 3, manufacturing a mould base for later use; 4, concentrically arranging the inner core and the outer core on the mould base; 5, reasonably adjusting the positions of the inner core and the outer core, planishing water-glass sand in the inner core and drying by utilizing carbon dioxide gas for later use; and 6, completing pouring molten steel within 1.5-2.5 minutes through a pouring opening on an sealing cover, holding the temperature for 7 hours and completing the casting. The method has the advantages of simple preparation process, reasonable design and short processing time, the production efficiency increased by more than 50%, guaranteed stability of the molded butterfly valve body, better roundness, no cracks on the surface and greatly enhanced tightness of the valve.

Description

The casting method of butterfly valve body

Technical field

The present invention relates to a kind of casting method, specifically a kind of casting method of butterfly valve body.

Background technology

At present, butterfly valve body is widely used in the closed conduit field of petrochemical industry, along with the caliber increasing of closed conduit; The bore of butterfly valve body also increases to more than 2 meters gradually, and we claim that diameter is the large valve body structure greater than 1.8 meters butterfly valve body, and the macrotype butterfly valve valve body does not have special Casting Equipment; Because theory analysis obtains: butterfly valve body 11 diameters are provided with flange 12 than big and two ends; The difficult control of surface quality and circularity after the moulding, and in the casting process since the molten steel shrinkage ratio be difficult to guarantee, that is to say flange end and can't blue end be to be difficult to control in synthermal shrinkage ratio down; Therefore be easy to occur losing circle and seminess in the casting process; The macrotype butterfly valve valve body of selling all is to adopt steel plate to be welded on the market now, and adopt the butterfly valve body that is welded to have following drawback: durability is lower, corrosion resistance and stable inequality; Seriously reduced the sealing property of valve, therefore caused and use the enterprise of this valve often to want shut-down (breakdown) mainteance.

Summary of the invention

The objective of the invention is deficiency for solving the problems of the technologies described above; A kind of casting method of butterfly valve body is provided; Its preparation technology is simple, and the processing time is short, and production efficiency improves more than 50%; And the circularity and the surface quality of the butterfly valve body of assurance casting are better, improve durability, corrosion resistance and the stability of valve body.

The present invention is the deficiency that solves the problems of the technologies described above, and the technical scheme that is adopted is: the casting method of butterfly valve body is characterized in that: concrete steps are following:

Step 1, make inner core: after the mould that will make the inner core core box is fixed; Chill evenly is set in mold slots, fills mold slots with water-glass sand then, after the water-glass sand surface is tied breather pipe is inserted in the mold slots; Feed carbon dioxide; Stop ventilation after 2-3 minutes, the mould of dismantling, the husky base of processing is subsequent use; Working face at husky base is smeared zircon flour coating, and smearing thickness is 1.5-2.5 ㎜, at room temperature husky base working face is lighted up to extinguishing naturally; The back adopts spray gun that the working face of husky base is toasted, and baking temperature is 800-1200 ℃, stoving time 2-3 minutes; The operation of repeat daub in this step, lighting, toasting 2-3 times, single inner core core box completes, and a plurality of fan-shaped inner core core boxes are formed the core arrangement of an annular, and the inner core of processing is subsequent use;

Step 2, make outer core core box according to the method for step 1; The outer cored structure of a plurality of fan-shaped outer core core boxes being formed an annular; Be provided with the circular die cavity that forms butterfly valve body end face flange at two on the core core box inner peripheral surface outside corresponding, the outer core of processing is subsequent use;

Step 3, employing water-glass sand are made mold base, after water-glass sand is tied, adopt the carbon dioxide oven dry; An annular lug is set on mold base; The annular lug upper surface is uniformly distributed with inlays chill, in the mold base center thick stick is set, and the mold base of processing is subsequent use;

Step 4, inner core is arranged on the inboard of annular lug on the mold base, the center of circle of inner core overlaps with an axle thick stick, in the gap between inner core and the thick stick, fills water-glass sand, and outer core is arranged on the outside of annular lug, and the center of circle of outer core overlaps with a thick stick;

Step 5, the center line that forms the circular die cavity of butterfly valve body end face flange on the core in addition are datum line; To distinguish mobile laterally 1.5-6 ㎜ perpendicular to inner core core box on the diameter of the inner core of this datum line and outer core and outer core core box; The inner core core box that is positioned at the datum line place keeps motionless with outer core core box; Adjust the position of all the other inner core core boxes and outer core core box; Make the inner peripheral surface of inner core outer circumference surface and outer core form slick and sly surface, then the water-glass sand in the inner core is tied, subsequent use with carbon dioxide oven dry back;

Step 6, on the outer circumference surface of core lagging casing is set outside, capping is set,, in 1.5-2.5 minutes, accomplish pouring molten steel, be incubated after 7 hours, cast completion through the sprue gate in the capping in the upper surface of inner core and outer core.

The invention has the beneficial effects as follows:

This preparation technology is simple, and is reasonable in design, and the processing time is short, enhances productivity more than 50%; Guarantee the stability of butterfly valve body after the moulding, circularity is better, and surperficial flawless improves the sealing of valve greatly; In technological process, rationally confirm the technological process of core box, guarantee the circularity and the positioning requirements of the outer core of inner core, secondly; It has been generally acknowledged that mould is round more, the product of casting is also just round more, yet in the actual casting moulding, adjusts the circularity of inner core and outer core in any case; The butterfly valve body circularity that casts out is all relatively poor, has caused the sealing property of valve to reduce greatly, learns through test of many times: because the butterfly valve body two ends are provided with flange; Have flange end with can't blue end under the situation of equal temperature, shrinkage ratio is inconsistent, so the circularity butterfly valve body that also can't cast out at high mould; Therefore, this process is adjusted the position of inner core and outer core in advance behind have good positioning inner core and outer core; The flange that prevents butterfly valve body causes valve body to lose circle taking place with cracks with can't blue end shrinkage ratio inconsistent, can't a revisal amount be provided blue end, this method process test of many times for butterfly valve body; The optimum value of adjusting to the revisal amount is 3-12 ㎜, is moulding can't be adjusted 3-12 ㎜ with outer core aperture by the blue inner core of holding laterally, and that side of formed strip flange end keeps motionless; Guaranteed that the product circularity after the casting is good, surface quality is good, improves the sealing property of valve greatly.

Description of drawings

Fig. 1 is a structure cutaway view of the present invention.

Fig. 2 is the structural representation of mold base.

Fig. 3 is the structural representation of inner core.

Fig. 4 is the front view of inner core core box.

Fig. 5 is the rearview of inner core core box.

Fig. 6 is the structural representation of outer core.

Fig. 7 is the front view of outer core core box.

Fig. 8 is the rearview of outer core core box.

Fig. 9 is the structural representation of butterfly valve body.

Mark among the figure: 1, mold base, 2, inner core, 3, outer core, 4, the axle thick stick, 5, lagging casing, 6, capping, 7, the inner core core box, 8, outer core core box, 9, annular lug, 10, chill, 11, butterfly valve body, 12, flange.

The specific embodiment

As shown in the figure, the Casting Equipment structure that butterfly valve body adopts is following:

Mainly constitute by mold base 1, inner core 2, outer core 3, lagging casing 5 and capping 6; Mold base 1 upper surface is provided with an annular lug 9, and inner core 2 and outer core 3 are provided with the both sides of annular lug 9, and the height of inner core 2 and outer core 3 equates; Be provided with a thick stick 4 at the center of mold base 1; Greater than inner core 2 and outer core 3 height, the purpose that a thick stick 4 is set mainly is: with outer core a positioning reference is provided for inner core is set, the outer circumference surface of core 3 is provided with lagging casing 5 to the height of axle thick stick 4 outside respectively; Inner core 2 with outside the upper end of core 3 be provided with capping 6, capping 6 is provided with sprue gate and rising head.

The central axes of described annular lug 9, inner core 2, outer core 3 and axle thick stick 4 guarantees the circularity of whole cast article.

The upper surface of described annular lug 9 evenly is inlaid with a plurality of chills 10, simultaneously is inlaid with chill 10 at the outer circumference surface of inner core 2 and the inner peripheral surface of outer core 3, adjusts molten steel and cools off contraction synchronously, product flawless and pore after the moulding.

Described mold base 1, inner core 2 and outer core 3 are made by water-glass sand, with water-glass sand according to the rules after the shape moulding, adopt carbon dioxide to dry up to make the model hardening, and be very easy to use.

Described inner core 2 is a loop configuration; Form by being fan-shaped inner core core box 7 more than two; On any inner core core box and end face that another inner core core box is connected, be equipped with groove, be on the connection end face of inner core core box 7 and be provided with groove, this groove the degree of depth generally at 2-3 ㎜.The purpose that groove is set is the shrinkage joint that is provided with in advance for to the mould that is heated.At first pass through the single inner core core box of mould molding, after surface treatment is firm, with the interior core component of an annular of a plurality of inner core core boxes compositions,

Described outer core 3 is a loop configuration, is fan-shaped outer core core box 8 by polylith and forms, and also is provided with groove on the connection end face of core core box 8 equally outside, this groove the degree of depth generally at 2-3 ㎜.At first, after surface treatment is firm, a plurality of outer core core boxes are formed the outer core component of an annular through the single outer core core box of mould molding.

The inner core core box that this place is described is for forming the fanlike die block of annular inner core, and outer core core box is for forming the fanlike die block of the outer core of annular.

Adopt the casting method step of this Casting Equipment making butterfly valve body following:

Embodiment one:

Step 1, making core arrangement: the inner core of annular is made up of a plurality of fan-shaped inner core core boxes,

It is raw material that the inner core core box adopts water-glass sand, after the mould of making the inner core core box is fixed, a plurality of chills is set evenly in mold slots; The quantity of chill is rationally confirmed according to the work area of inner core core box; Water-glass sand is filled mold slots, and the mouth of pipe that will be connected with carbon dioxide after the surface is tied inserts in the mold slots, and carbon dioxide and water-glass sand fully react back water-glass sand hardening after 2 minutes; The mould of dismantling, the husky base back that completes is subsequent use; The working face of husky base after the moulding is smeared zircon flour coating, and smearing thickness is 1.5 ㎜, at room temperature lights up to extinguishing naturally; The back adopts the liquefied gas spray gun that the working face of husky base is toasted, and baking temperature is at 800 ℃, and stoving time was at 2 minutes; Repeat to smear in this step, light, after the baking process flow process 3 times, single inner core core box completes, and a plurality of fan-shaped inner core core boxes are formed the core arrangement of an annular, inner core completes subsequent use;

Step 2, make outer core core box according to the step 1 method; Outer core is based on the size Selection mould of reality; The preparation method is identical with step 1; The outer cored structure of a plurality of fan-shaped outer core core boxes being formed an annular; Be provided with the circular die cavity that forms butterfly valve body end face flange at two on the core core box inner peripheral surface outside corresponding; When flange was excessive, the quantity of the outer core core box that circular die cavity takies also increased thereupon, and outer core completes subsequent use;

Step 3, employing water-glass sand are made mold base, after water-glass sand is tied, adopt the carbon dioxide oven dry; Mold base is the plane of an annular after accomplishing, and on mold base, is provided with an annular lug, the central axis of annular lug and the central axes of mold base; The height of annular lug exceeds mold base 30-50 ㎜, preferred 40 ㎜, and the annular lug upper surface is uniformly distributed with and is inlaid with chill; In the mold base center thick stick is set, mold base is subsequent use after accomplishing;

Step 4, inner core is arranged on the inboard of annular lug; Each inner core core box as positioning reference, after the circularity of adjustment inner core, is filled water-glass sand in the gap between inner core and axle thick stick with the axle thick stick; Outer core is arranged on the outside of annular lug; Outer core core box with the axle thick stick as positioning reference, the adjustment outer core circularity after, subsequent use;

Step 5, outer in-core surface, the common shape that is shaped as the foundry goods butterfly valve body that constitutes of interior core outer surface and annular lug upper surface; With the center line of an end flanges of moulding butterfly valve body is datum line; Intersection point with this datum line and axle thick stick axis is the center of circle; This datum line is to both sides difference half-twist; The inner core core box that will be positioned at this end and outer core core box (for the side away from the axle thick stick) all laterally move 1.5 ㎜, and the inner core core box that is positioned at flange center line place is motionless with outer core core box, and adjust remaining inner core core box and make that with outer core core box position the inner peripheral surface of inner core outer circumference surface and outer core is that a slyness is surperficial; After the water-glass sand in the inner core is tied, adopt carbon dioxide oven dry back subsequent use;

Step 6, the outer circumference surface of core is provided with lagging casing outside, in the upper surface of inner core and outer core capping is set, in the position, sprue gate in the capping with molten steel casting complete in 1.5 minutes, after the back is incubated 7 hours, casting.

Described zircon flour coating main component is made up of zirconium English powder, alcohol, binding agent, and market is on sale.

Embodiment two:The casting method of butterfly valve body is characterized in that: concrete steps are following:

Step 1, make inner core: after the mould that will make the inner core core box is fixed; Chill evenly is set in mold slots, fills mold slots with water-glass sand then, after the water-glass sand surface is tied breather pipe is inserted in the mold slots; Feed carbon dioxide; Stop ventilation after 3 minutes, the mould of dismantling, the husky base of processing is subsequent use; Working face at husky base is smeared zircon flour coating, and smearing thickness is 2.5 ㎜, at room temperature husky base is lighted up to extinguishing naturally; The back adopts spray gun that the working face of husky base is toasted, and baking temperature is 1200 ℃, stoving time 3 minutes; The operation of repeat daub in this step, lighting, toasting 2 times, single inner core core box completes, and a plurality of fan-shaped inner core core boxes are formed the core arrangement of an annular, and the inner core of processing is subsequent use;

Step 5, the center line that forms the circular die cavity of butterfly valve body end face flange on the core in addition are datum line; To distinguish mobile laterally 6 ㎜ perpendicular to inner core core box on the diameter of the inner core of this datum line and outer core and outer core core box; The inner core core box that is positioned at the datum line place keeps motionless with outer core core box; Adjust the position of all the other inner core core boxes and outer core core box; Make the inner peripheral surface of inner core outer circumference surface and outer core form slick and sly surface, then the water-glass sand in the inner core is tied, subsequent use with carbon dioxide oven dry back;

Step 6, on the outer circumference surface of core lagging casing is set outside, capping is set,, in 2.5 minutes, accomplish pouring molten steel, be incubated after 7 hours, cast completion through the sprue gate in the capping in the upper surface of inner core and outer core.

Embodiment three:The casting method of butterfly valve body is characterized in that: concrete steps are following:

Step 1, make inner core: after the mould that will make the inner core core box is fixed; Chill evenly is set in mold slots, fills mold slots with water-glass sand then, after the water-glass sand surface is tied breather pipe is inserted in the mold slots; Feed carbon dioxide; 2.5 stop ventilation after minute, the mould of dismantling, the husky base of processing is subsequent use; Working face at husky base is smeared zircon flour coating, and smearing thickness is 2 ㎜, at room temperature husky base is lighted up to extinguishing naturally; The back adopts spray gun that the working face of husky base is toasted, and baking temperature is 1000 ℃, stoving time 3 minutes; The operation of repeat daub in this step, lighting, toasting 3 times, single inner core core box completes, and a plurality of fan-shaped inner core core boxes are formed the core arrangement of an annular, and the inner core of processing is subsequent use;

Step 5, the center line that forms the circular die cavity of butterfly valve body end face flange on the core in addition are datum line; To distinguish mobile laterally 3 ㎜ perpendicular to inner core core box on the diameter of the inner core of this datum line and outer core and outer core core box; The inner core core box that is positioned at the datum line place keeps motionless with outer core core box; Adjust the position of all the other inner core core boxes and outer core core box; Make the inner peripheral surface of inner core outer circumference surface and outer core form slick and sly surface, then the water-glass sand in the inner core is tied, subsequent use with carbon dioxide oven dry back;

Step 6, on the outer circumference surface of core lagging casing is set outside, capping is set,, in 2 minutes, accomplish pouring molten steel, be incubated after 7 hours, cast completion through the sprue gate in the capping in the upper surface of inner core and outer core.

Claims

1. the casting method of butterfly valve body, it is characterized in that: concrete steps are following:

Step 1, make inner core: after the mould that will make the inner core core box is fixed; Chill evenly is set in mold slots, fills mold slots with water-glass sand then, after the water-glass sand surface is tied breather pipe is inserted in the mold slots; Feed carbon dioxide; Stop ventilation after 2-3 minutes, the mould of dismantling, the husky base of processing is subsequent use; Working face at husky base is smeared zircon flour coating, and smearing thickness is 1.5-2.5 ㎜, at room temperature husky base is lighted up to extinguishing naturally; Toast the working face of husky base the back, and baking temperature is 800-1200 ℃, stoving time 2-3 minutes; The operation of repeat daub in this step, lighting, toasting 2-3 times, single inner core core box completes, and a plurality of fan-shaped inner core core boxes are formed the core arrangement of an annular, and the inner core of processing is subsequent use;

Step 6, on the outer circumference surface of core lagging casing is set outside, capping is set,, in 1.5-2.5 minutes, accomplish pouring molten steel, be incubated after 7 hours, cast completion through the sprue gate in the capping in the upper surface of inner core and outer core;

Described zircon flour coating main component is made up of zirconium English powder, alcohol, binding agent.