RU2021876C1 - Mould for casting by submerging - Google Patents

Abstract

FIELD: metallurgy. SUBSTANCE: mould has outer case, shape generating shell with bottom feeders and a suspension. Outer case is reused. Lower bead of the case forms bottom hole with reversed cone. Shape generating shell has a flange located inside bottom hole in case metal receiver. Hole is of the same shape as the flange. The mould has a weight to hold down shape generating shell. The suspension has a lever connected to the weight, and handle of the lever is used for mould transfer. EFFECT: increased productivity. 2 cl, 1 dwg

Description

 The invention relates to foundry, mainly to molds made by various forming methods and intended for casting by immersion.

 Known mold for immersion by auth. N 595068, investment casting and containing a support layer forming the working cavity of the mold, side and bottom feeders. This form is considered as an analogue.

 In this form, the support filler is made of a monolithic ethyl silicate mixture according to the Shaw method and after heat treatment has a surface network of cracks. When the mold is immersed in the melt, its outer surface comes into contact with the melt, clogging it.

 The closest in technical essence and the achieved effect to the invention is the mold [1], made by investment casting and containing the outer shell in the form of a glass, rigidly connected to the facing layer forming the working cavity of the mold by bottom and side feeders, and molded from the inside.

 The use of forms of this design somewhat reduces the consumption of an expensive binder - ethyl silicate, but the consumption of refractory materials remains high. In addition, the manufacture of a single heat-resistant shell requires the use of scarce electrocorundum, which limits the scope of use of these forms.

 For the manufacture of molds, high laboriousness is required, especially when assembling the model block, because it is necessary to make a glass from the model mass and solder the investment models to the inner surface of the glass. Hence, the application of refractory coating layers and their drying are difficult due to the presence of deaf pockets, and therefore requires the use of sophisticated vacuum equipment. The use of such forms does not exclude clogging of the ceramic melt as a result of cracking of the shell during calcination or immersion of the form in the melt.

 The use of a separate metal skeleton-skeleton for each form, its molding with a self-hardening filler and subsequent calcination of the entire form assembly lead to an increase in labor input, high consumption of self-hardening molding composition and energy resources.

 The aim of the invention is to reduce the manufacturing cycle of castings by eliminating the support layer, reducing the complexity of manufacturing molds, the consumption of molding materials and energy.

 This is achieved by the fact that in the mold for immersion casting, having a forming shell with bottom feeders, the outer casing is made in the form of a cylindrical or box-shaped, reusable form, in the lower part of which is made an inner flange forming a bottom hole with a reverse cone, and the forming shell is made with a flanging flange located in the bottom hole of the casing, repeating its configuration, and drawn up from above by a load.

 In addition, in addition, the suspension form is made with a rod connected to the load.

 In order to expand the technological capabilities of manufacturing casting molds, prefabricated molds of various materials made by various forming methods can be used as the forming shell, and the outer casing can be made of metal.

 And in order to ensure transportation and fastening of the mold to the manipulator (robot), the handle of the mold suspension serves as a gripper.

 Elimination of fixation of the forming shell and the bracket of the frame due to molding by a self-hardening supporting filler, achieved in the claimed form due to the design of the docking assembly of the casing and the forming shell, equipped with a load to compress it to the casing, completely eliminates the supporting self-hardening filler. The mold-forming shell is backfilled into the casing to a certain height only to create directional solidification along the casting height and additionally to seal the docking unit.

 This shortens the cycle of manufacturing molds and reduces the complexity by eliminating the operation of forming the shell together with the frame bracket self-hardening composition, its hardening and calcination. This reduces the consumption of binders and refractory filler, and energy for the joint calcination of the casing, the working form and refractory filler.

 Important from the point of view of reducing the complexity and consumption of scarce materials in the manufacture of outer casings and in the manufacture of removable devices from heat-resistant stainless steel is that this mold design allows you to reduce the total number of reusable parts of the mold (casing and suspension load) several times, t .to. Due to the quick assembly of the mold, they can be used several times during one melting-pouring.

 The drawing shows a cross section of the form.

 The dipping mold contains an outer reusable ceramic casing 1 having a lower flange 2 with a reverse cone. Inside the casing, in the docking unit, limited by the inner shoulder, a working form 3 with bottom feeders 4 is installed, having a corresponding flange flange 5, which tightly enters the assembly without a gap and does not reach 2-3 mm to the lower edge of the outer casing.

 In the upper part of the mold for immersion casting, a suspension rod 6 of the mold is made, connected to the load and serving to tighten the working mold to the docking unit. The mold suspension contains a screw or other action rod, which rests with the heel against the upper edge of the working form, and the suspension rod handle serves to transport the entire assembled form.

 In addition, the attachment of removable suspensions, for example, an external grip with independent movement of the paws, can also be carried out for the upper, inner or outer flange of the casing, for the half-openings of the casing, etc.

 The working form with a cavity for casting can be ceramic - made by investment casting with the application of several layers of refractory coatings; prefabricated rod - made according to constant models using rod mixtures on various fasteners, mixtures on thermosetting resins, liquid bulk mixtures and others used in foundry.

 Molds or elements for prefabricated molds undergo appropriate heat treatment (drying or calcining) according to the technological process.

 Hot or chilled molds 3 are installed inside the outer casing 1, as shown in the drawing. Next, a removable suspension device 6 of the form is installed, for example, it is turned clockwise. In this case, metal leads with heads are included in the slots of the support strips of the form suspension device.

 After installing the removable suspension, the working form 3 is slightly tightened, for example, by weight or by turning the rod handle to the stop of the special heel in the upper edge of the form 3.

 To control the crystallization rate and seal the mold docking unit, a dry filler, for example quartz sand, electrocorundum, zircon, metal sand or shot, etc., is poured to a certain height inside the outer casing. depending on the technological instructions for each specific part. This allows you to improve the heat sink by radiation from the upper part of the casting, heat transfer from the middle and lower parts of the shell and provide additional directionality of solidification along the height of the casting.

Form thus prepared is placed in the heating furnace for heating the assembled mold to a certain temperature, but not less than ^about 100-200 C. It is allowed filling particulate filler carried out after preheating the assembled form.

 Next, the mold is poured in the hot state by immersion, for which the mold is suspended by the handle of the rod to the gripper of the manipulator and immersed in the melt at a certain speed. Several cooled cast molds are disassembled, first pouring a dry backfill, and then loosening the fixation of the working form 3 using the suspension rod 6 of the mold, remove the suspension device 6 and remove the filled mold 3 from the outer casing through the upper hole.

 Next, the reusable casing is cleaned and used for subsequent assembly of molds and pouring during the current melting - pouring together with a removable suspension or cargo.

 A positive effect from the implementation of the present invention is achieved through the use of the outer casing design and the working form with a special docking unit, a removable device for fixing the shape and at the same time using the suspension rod handle as a mount for attachment to the manipulator grip. All this makes it possible to exclude a self-hardening support filler for assembling the mold, and therefore the mold manufacturing cycle is reduced due to a reduction in the calcination time of the mold by 3-4 times and mold assembly. The complexity of manufacturing the mold is also reduced by eliminating the molding operation; molding compound consumption.

 In addition, the debt of outer shells and removable reusable suspensions is reduced, i.e. their required quantity is reduced due to their repeated use during one heat - pouring.

Claims (2)

 1. FORM FOR IMMERSION INJECTION, containing a forming shell with bottom feeders, a casing and a suspension, characterized in that, in order to reduce the consumption of materials and reduce the complexity of manufacturing the mold by eliminating the self-hardening layer, it is equipped with a load to preload the forming casing, while the casing made reusable, with a lower flange forming a bottom hole with a reverse cone, and the forming shell is made with a flange located in the bottom hole of the casing and repeating its conf uracil.  2. The mold according to claim 1, characterized in that the suspension is made with a rod connected to the load.

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