RU168847U1 - PRESS FORM FOR MAKING CARBON MODELS - Google Patents

Abstract

The present invention relates to the field of foundry, in particular to molds for the manufacture of investment castings. The mold can be grown on a 3D printer and made of polymers and / or copolymers, as well as metal powders. The mold for making a lost wax mold consists of two half-molds: the upper mold and the lower mold. The pressing sleeve is installed in the upper half-mold. The press-in hole of the press-in sleeve is connected by a gate with a forming cavity. Gate runs can be at least as many as forming cavities. A locking latch is installed in the upper half-mold for fixing the press-in sleeve in a strictly installed position and pushers that provide a direct effect on the model from the mold. In the upper half-mold and the lower half-mold, a detachable profile connection is made so that the upper and lower half-molds are reliably mated with each other without displacement, without violating the dimensions and geometry of the part. Also made cooling elements in the form of open cavities, which are designed in such a way that the cooling rate of the model mass is reduced without the risk of destruction of the molds. Thus, as a result of the proposed solution, a technical result is obtained: a mold for the manufacture of investment casting is created, which has a design with reduced metal consumption and, accordingly, mass due to the use of polymers and copolymers, in particular ABS plastic, which allows to obtain a model from model mass, accelerating the process of cooling the model mass due to

Description

The invention relates to the field of foundry, in particular to molds for the manufacture of investment castings.

Various types of molds are known for the production of investment castings described in B.S. Kurchman's “Lost wax casting”, Moscow, ed. OBORONGIZ, 1958, p. 26. The choice of type, design and material of which the mold is made depends on the nature of production and the requirements for castings. In large-scale production, molds are made of metal (aluminum and steel). If it is necessary to obtain accurate and complex castings, single-cavity molds made by machining are selected if a small amount of castings is required. The lack of mechanization in the development of molds limits the application of the lost wax method due to the significant mass of aluminum molds, i.e. a large mass of molds limits the use of castings in products by dimensions. Another disadvantage of metal molds is the poor fillability of extended thin walls, which limits the range of thin-walled castings, which in practice is solved by increasing the thickness of the walls and ribs. To quickly manufacture and facilitate fine-tuning, molds are made with the smallest number of connectors, they must be lightweight and have reliable fast-acting locking devices. The best locking devices are hydraulic and pneumatic clamps. Particular attention is paid to taking into account all shrinkages and extensions of models, molds and metal during the casting process, where the shrinkage is greatly affected by the mold material, the compaction time of the mold, its compliance and the geometry of the part itself. In the molds there should not be any irregularities that make it difficult to remove the model from the molds, it is necessary to carefully maintain the slopes and cones. Mold materials should provide durability. However, molds made of metal are expensive, the duration of machining in the manufacture of parts is high, and the locking and centering mechanisms of the half-molds are relatively complex.

A known mold for the manufacture of investment casting is described in the copyright certificate SU No. 1217557, IPC B22C 7/02, B22D 15/00, publ. 03/15/1986 The mold contains a thin-walled shell, a housing, fastening ties connecting the shell to the housing, a loose filler located in the inner cavity between the housing and the thin-walled shell, and supply pipes to the inner cavity of the shell and the removal of the fluid. However, the mold has a complex structure and manufacturing complexity. The presence of a shell that forms the cavity of the lost wax model in the mold limits the use of the mold for the manufacture of castings.

The closest analogue is the mold for the manufacture of investment casting, described in the application of the Russian Federation No. 95100334, IPC B22C 7/02, publ. 01/27/1997, the application proposed the design of the mold, consisting of two half-molds, with perforated walls, a lid and a bottom for the manufacture of investment casting. The body of the mold is made of foam, preferably made of expanded polystyrene with closed porosity, through which perforated thin-walled tubes pass connecting the opposite walls of the housing and form through holes. The press-in hole is made along the entire length with a metal sleeve, the model mass is pressed into the forming cavity, and metal refrigerators are installed in the places where the investment models are thickened. However, the mold has a complex structure, complex locking and centering mechanisms, which means that the complexity of manufacturing the mold increases. In addition, such molds with metal refrigerators are expensive and have a large mass compared with the invention.

The objective of the invention is the creation of a mold for the manufacture of lost wax models with improved mass and dimensional indicators, with a simpler manufacturing method, with a quick cooling process.

The technical result is the creation of a mold for the manufacture of investment castings, which has a design with reduced metal consumption and, accordingly, mass due to the use of polymers and copolymers, in particular ABS plastic, which allows to obtain a model from model mass, accelerating the cooling process of model mass through the use of open cavities using a variety of cooling media (air, water, and other gases and media) and an effective heat exchange method.

To achieve the technical result, a mold design for the production of investment castings is proposed, consisting of two half-molds, comprising: a press-in hole in the press-in sleeve, at least one mold-forming cavity in the upper and / or lower half-mold for pressing the model mass, cooling elements, unlike the known, half-molds are interfaced with a detachable profile connection, the press-in sleeve is made with the possibility of rotation around its axis and its fixation in the upper half-mold, ressovochnoe opening is connected to at least one sprue stroke with at least one molding cavity, cooling elements are arranged in the upper and / or lower mold part and formed as at least one open cavity opening onto an outer surface of the mold. In addition, half-forms and structural elements can be grown on a 3D printer and made from polymers and / or copolymers, as well as metal powders.

In FIG. 1 shows the main view of the mold. In FIG. 2 is a top view. In FIG. 3 shows a section AA. In FIG. 4 shows a section BB.

The mold for making a lost wax mold consists of two half-molds: the upper mold 1 and the lower mold 2 (Fig. 1). A press-in sleeve 3 is installed in the upper half-mold 1. The press-in hole of the press-in sleeve 3 is connected by the gate 4 (Fig. 4) with the forming cavity 5 (Fig. 3). The gate runs 4 can be at least as many as forming cavities 5. For example, in FIG. 4 shows the design of the mold with 4 gateways 4 and 4 of the forming cavities 5. If the forming cavities 5 are complex, then the gateways 4 may be larger. In the upper half-mold 1, a locking latch 6 is installed (Fig. 1) for fixing the press-in sleeve 3 in a strictly installed position and pushers 7 (Fig. 1), which provide a direct effect on the model of its removal from the mold. In the upper half-mold 1 and lower half-mold 2, a detachable profile connection 8 is made (Fig. 3) so that the upper 1 and lower 2 half-molds are reliably mated with each other without displacement, without violating the dimensions and geometry of the part. For reliable bonding, you can use pneumatic and hydraulic clamps or a press, as well as clamps (not shown in FIG.), Which are more suitable because of their accessibility and simplicity. Also made cooling elements 9 in the form of open cavities, which are designed so that the cooling rate of the model mass is reduced without risk of destruction of the half-molds 1 and 2. For example, in Fig. 3 in the upper half-mold 1 there are four cooling elements 9, and one in the lower one.

The work of the mold for the manufacture of investment casting is as follows. Molds and the necessary structural elements are designed in a CAD system and grown on a 3D printer and / or made by any other known method from polymers and / or copolymers, for example, from ABS plastic or metal powders, or other materials that provide long-term operation of the mold . Depending on the required cleanliness of the forming surface, it is cycled manually or mechanically, and structural elements are also adjusted (upper half-mold 1, lower half-mold 2, press-in sleeve 3, pushers 7, retainer 6) using a cycle. Pushers 7 are made by turning. The mold is blown through with compressed air. Check the operation of the pushers 7 and set them to the upper position. The forming surface is lubricated with silicone grease. Connect the upper half-mold 1 with the lower half-mold 2. A press-in sleeve 3 is installed in the upper half-mold 1, and in this half-form 1 it is fixed with a locking latch 6 so that the outputs of the gateways 4 coincide with the inputs of the forming cavities 5. Then, using the press-in sleeve 3 through the gate the passages 4 are pressed with a model mass into the forming cavities 5 in the mold. To accelerate cooling, the mold with the pressed model mass is placed in the cooling medium, thanks to the cooling elements 9, the cooling process is accelerated. The cooling rate will depend on the wall thickness of the mold between the forming cavity and the cooling element, the temperature of the cooling medium and the amount of model mass pressed into the mold. After pressing, the locking latch 6 is removed from the upper half-mold 1 and the excess model mass remaining after pressing is cut off by turning the press-in sleeve 3 to either side. Compress the upper half-mold 1 and the lower half-mold 2 with clamps, remove the press-fit sleeve 3 from the upper half-mold 1 and remove the model mass remaining after pressing from the press-on sleeve 3. After the model mass has hardened, remove the clamps, disassemble the mold and use the pushers 7 to remove the finished model from forming cavities 5.

Thus, as a result of the proposed solution, a technical result is obtained: a mold for the manufacture of investment casting is created, which has a design with reduced metal consumption and, accordingly, mass due to the use of polymers and copolymers, in particular ABS plastic, which allows to obtain a model from model mass, accelerating the process of cooling the model mass through the use of open cavities using a variety of cooling media (air, water, and other gases and media) and an effective method of flat exchange.

Claims (3)

1. A mold for the manufacture of investment castings, containing two half-molds, a pressing sleeve with a pressing hole connected by at least one gateway with at least one forming cavity in the upper and / or lower half-mold for pressing the model mass, while the pressing sleeve made with the possibility of rotation around its axis and fixing it in the upper half-mold, characterized in that in the upper and / or lower half-mold there are open cooling cavities that open onto the outer surface s mold. 2. The mold according to claim 1, characterized in that its elements are grown on a 3D printer. 3. The mold according to claim 1, characterized in that it is made of polymers and copolymers, metal powders.

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