BR102016025816A2 - MANUFACTURING MACHINERY PROCESS - Google Patents

Abstract

"Machining core fabrication process". Has treated the present patent application to a machining core fabrication process in which it is applied to the field of fabrication core fabrication core machining processes formed by a thermoplastic polymer core (5) and mixtures thereof, preferably made of eps, polyurethane, fiberglass, resin and other polymers may be used to form a solid and lightweight core (5) already in the desired external shape, to be externally coated by a sand cover layer (7) that occurs internally in the mold (1) during the manufacturing process, which results in a masking core with a thermoplastic polymer core.

Description

(54) Title: MACHINE MAKING PROCESS FOR MACHINERY (51) Int. Cl .: B22C 9/02; B22C 2/15; B29C 41/08; B29C 33/54; B29C 63/22 (52) CPC: B22C 9/02, B22C 15/02, B29C 41/08, B29C 33/54, B29C 63/22 (73) Owner (s): RODRIGO LUIZ DA SILVA, SILVONEI DA SILVA ( 72) Inventor (s): SILVONEI DA SILVA (74) Attorney (s): SANDRO CONRADO DA SILVA (57) Abstract: MACHINE MANUFACTURING PROCESS FOR MACHINERY. This invention patent application was treated for a male manufacturing process for machining in which it is applied to the field of tapping processes for molding with sand molds, formed through a core (5) of thermoplastic polymer and its mixtures, preferably manufactured in EPS, which can be used polyurethane, fiberglass, resin among other polymers, to form a solid and light core (5) already in the desired external shape, to be covered externally by a layer of sand covering (7) that occurs internally in the mold (1) during the manufacturing process, which results in a tapping core with a core formed of thermoplastic polymer.

1/7 “MACHINE MAKING PROCESS FOR MACHINERY”.

FIELD OF APPLICATION [00] The present application for an invention patent will be applied to the field of manufacturing processes for tapping cores for molding with sand molds, composite of refractory materials or similar to create castings.

STATE OF THE TECHNIQUE [002] Milling is the process of obtaining agglomerates of sand and resin that work as internal molds, giving shape to the external recesses and internal cavities of the casting, thus ensuring its geometry and internal tolerances specified by the part.

[003] In the casting processes, the critical operations refer in general, to the molding of the part and the machining of its components, which consists of obtaining cores normally made from refractory materials and adding them in the molds, aiming at the formation of cavities, holes and recesses of parts.

[004] For the optimal functioning of machines and parts in general it is necessary to use an air or liquid circulation system inside. In the case of cast iron parts, the application of casting cores is required to obtain these ducts. The main disadvantages pertaining to machining reside in the variables introduced in the project specification, such as the possibility of blowing and blistering due to inadequate gas removal, or in more extreme situations, the expulsion of liquid metal from inside the molds.

[005] Another relevant factor is the correct positioning of the elements that make up the mold and the core. The absence of adequate control at this stage can result in dimensional deviations to values beyond the tolerance norms.

[006] This problem occurs because the resistance of the males made of sand and its mixture results in fragile males that break

5/21

2/7 easily either during its molding, that is, during its placement in the final mold in the core-to-core function.

[007] Another problem in the current processes is the fact that they use 100% sand to form the males for macaria. This sand turns into contaminated lumps after the process that cannot be reused in another smelting process. Even if the grains are broken down and separated, they are impregnated with resins and, consequently, with their original granulometric distribution, they are altered and inadequate for their reuse. These factors compel companies to discard this sand in industrial landfills, which increases the final cost of production.

[008] These resins are presented in the male manufacturing process, and work to bind sand grains, such as furanic, phenolic, urea-formaldehyde and acrylic resins, in addition to chemical catalysts. These organic constituents are called in the foundries as sand binders. The processes that use these binders were developed to solve problems of hardening speed, resistances and collapsibility of the molding and improvement in the quality of the produced metallic part. (MOREIRA, Maria Teresa Pereira de Oliva Teles. Environmental contamination associated with residual foundry sands. 2004. 218 pages. Thesis (PhD in Chemical Engineering). Faculty of Engineering, University of Porto (FEUP), 2004).

[009] That is to say, the tap cores as well as the molds currently manufactured are basically made up of sand with mixtures of additives such as that disclosed in document US5651815A which describes an additive for foundry sand that comprises a mixture of iron oxide, carbonaceous material highly volatile such as gilsonite, and four pieces of metallurgical coke. The additive is used as a quarter of the foundry sand premix, the other three quarters consisting essentially of clays.

[010] Another process that deals directly with the creation of additives for use in foundry sand for male tappers is disclosed in US4735973A, which describes an additive for base sand, a6 / 21

3/7 molds for casting, sand molding used to produce cores and molds to improve the quality of molded parts.

[011] We can also mention the document BRPI9710401-9B1 which discloses a composition for the manufacture of cores and casting molds and a process for the manufacture of core or casting die using suitable molding sand to manufacture cores and casting molds. The molding sand consists of hollow aluminum silicate microspheres, preferably with an aluminum content between 15 and 45% by weight, a wall thickness between 3 and 10% particle diameter and a particle size between 10 and 350 pm, useful for making low density taps for tapping tapes useful in making cast iron.

[012] In this way, according to the documents above, the demand for solutions that reduce the use of sand for the manufacture of taps for males, currently manufactured entirely in sand and its mixtures, is perceived, which gives the males excessive weight and low mechanical resistance, mainly on parts with many curves and ribs or small parts.

[013] The process developed here by the author differs from the current ones known in the current technique that use raw material based on 100% sand with the addition of additives.

[014] The process claimed here is designed to obtain a core for machining in which it is formed by a light and resistant core made of thermoplastic polymer, preferably in EPS (Expanded Polystyrene) popularly known as Styrofoam, among other polymers and their mixtures.

[015] This EPS core is externally covered with a layer of sand. Thus obtaining, after the manufacturing process, a tapping tap, light in its weight and mechanically resistant, and of excellent quality for its purpose, overcoming the inconveniences of taps currently manufactured entirely in sand and its mixtures.

OBJECTIVES OF THE INVENTION

7/21

4/7 [016] The present request consists of obtaining a core tap made with an inner core made of thermoplastic polymer, such as EPS, polyurethane among other mixtures, resins or fiberglass, intended to form a solid core and lightweight, already in the desired shape to be covered externally by a layer of sand and its mixtures, which allows to completely cover the entire external surface of the referred core.

[017] After the thermoplastic polymer core is removed from the mold, it is already covered with a layer of sand and ready to be used as a core for machining, presenting excellent mechanical resistance, dimension and shape already defined to be used as a core for machining in metal parts casting processes.

BRIEF DESCRIPTION OF THE INVENTION [018] The invention consists of a process developed to manufacture a core for machining in which its core is made of thermoplastic polymer and mixtures such as EPS, polyurethane (PU), among other mixtures. To form a solid and light core in plastic material in which it will be covered by a layer of sand and its mixtures made to not melt at melting temperatures. Forming a solid body, mechanically resistant and light, to be used as a tap for machining in the manufacturing processes of castings.

[019] The manufacturing process begins with the opening of a mold for placing a wedge at the base of the inner part of the mold that will serve as a support for the plastic core.

[020] This wedge can be a base of sand and its mixtures or be of another material and shape, placed or deposited automatically or manually that has the purpose of supporting the solid core and already in the desired external shape.

[021] The inner surface of the mold wall is identical to the outer surface of the core, but the dimension is different. That is, the dimension of the core is smaller than the inner part of the mold.

[022] This difference in dimension creates a space for the passage of sand in which it is applied by external equipment.

8/21

5/7 [023] This void created that formed a gap between the inner surface of the mold in relation to the outer surface (9) of the core (5) is filled with sand and its mixtures under pressure, to create a layer of covering compact sand that covers the entire outside of the core (5).

[024] The width of this gap spacing is what defines the thickness of the sand cover layer in the core.

[025] The solid core, covered with the sand covering layer, forms an effective solid coating to prevent the melted metal from adhering and to allow the release of the core after molding the product.

[026] The process in this way allows to create a layer of sand cover and its mixtures that covers the entire outer part of the core maintaining the outer contours of the core, allowing to create tap cores with various shapes and sizes that were not previously possible.

[027] It was also possible to reduce the volume of sand used in the process of making cores for macaria, consequently reducing production costs and reducing the tons of sand that are sent to industrial landfills.

[028] With the process it was possible to obtain a tap light in its weight and covered with a solid layer of pure mineral sands cover or with mixtures, effective to prevent the adherence of the molten metal and allow the release of the tap after molding the product.

DESCRIPTION OF THE FIGURES [029] The attached drawings briefly expose the process of making tapping taps, which together with the numerical references detailed below, is more easily understood, although this invention is capable of being realized in many different constructive forms , always customized for each application, not shown in the drawings that will be described here in detail and ways for carrying out said invention.

9/21

6/7 [030] Figure 1 shows an example view of an open mold showing the mounting point of the core support block.

[031] Figure 2 shows an example view of a core positioned inside the closed mold, showing the free gaps to be filled with sand.

[032] Figure 3 shows an example view of a core positioned inside the closed mold, showing the free gaps being filled with sand.

[033] Figure 4 shows an example view of a core already covered with a layer of sand.

[034] Figure 5 shows an exemplary view of a male model already ready and covered with a layer of sand cover.

[035] Figure 6 presents an exemplary view of a male model for machining already ready and covered with a layer of sand cover with detail in section showing the core.

DETAILED DESCRIPTION OF THE INVENTION [036] The manufacturing process is characterized by starting with the opening of the mold (1) in which it is characterized by the base (2) inside (3) receiving the accommodation automatically or manually from the shim (4) supporting the core (5) of thermoplastic polymer and its mixtures, preferably in EPS, which may also be polyurethane, resin among other polymers and their mixtures; the core (5) already solid and in the desired external shape, following the process with the closing of the mold (1) to occur the blowing, injection or other way of making it possible to deposit the sand inside the inner part (3) of the mold (1) , then gassing and purging is carried out following the opening of the mold (1) to remove the core (6) with core (5) already covered by a layer of sand (7) that covers the entire external surface (8 ) of the core (5).

[037] In the process, the internal part (3) of the mold (1) has the same shape as the core (5), but has a smaller dimension with

10/21

7/7 the objective of creating a gap (9) between the inner surface (10) of the mold (1) in relation to the outer surface (8) of the core (5).

[038] This empty space created by the gap (9) formed between the inner surface (10) of the mold (1) in relation to the outer surface (8) the core (5) form a passage to be filled with sand and its mixtures under pressure to create a compact sand cover layer (7) over the entire outer part of the core (5).

[039] The sand covering layer (7) and its mixtures covers the entire outer part of the core (5) maintaining the outer contours of the core (5).

[040] The thickness of the sand cover layer (7) will be defined according to the difference in the spacing distance between the inner surface (10) of the mold (1) in relation to the outer surface (8) of the core (5).

[041] The solid core (5) covered by a layer of sand (7), forms an effective solid coating to prevent the molten metal from adhering and allow the release of the core after molding the product.

[042] The process is used to manufacture tap cores with a core (5) of thermoplastic polymer, preferably in EPS coated with a layer of sand cover (7) and mixtures thereof.

[043] The application of the sand cover layer (7) on the outside of the core (5), occurs inside the mold (2) of the tooling filled by appropriate equipment.

[044] The sand cover layer (7) is made to not melt at melting temperatures.

[045] The sand cover layer (7) consists of pure or mixed mineral sands.

11/21

1/2

Claims (10)

R E I V I N D I C A TION 1) "MACHINE MAKING PROCESS FOR MACHINERY", understood to start with the opening of the mold (1) in which it is characterized by the base (2) on the inside (3) receiving the accommodation automatically or manually from the shim (4) supporting the core (5) of thermoplastic polymer and its mixtures already in the desired external shape, following with the closing of the mold (1) and filling with sand into the internal part (3) for compaction following with the opening and removal of the core (6) with core (5) covered by a layer of sand (7). 2) "MACHINE MAKING PROCESS FOR MACHINERY", according to claim 1, comprising the core (5) of thermoplastic polymer being characterized by being in EPS. 3) "MACHINE MAKING PROCESS FOR MACHINERY", according to claim 1, comprising the core (5) of thermoplastic polymer being characterized by having the variant of being made of polyurethane, resin or fiberglass. 4) "MACHINE MAKING PROCESS FOR MACHINERY", according to claim 1, comprising the inner surface (10) of the inner part (3) of the mold (1) being characterized by having the same shape as the outer surface (9) of the core (5). 5) “MACHINE MAKING PROCESS FOR MACHINERY”, according to claim 1, comprising the difference in dimension between the internal surface (10) of the internal part (3) of the mold (1) in relation to the external surface (8) of the core (5) is characterized by creating a gap (9) for passage, accommodation and compaction of sand. 6) "MACHINE MAKING PROCESS FOR MACHINERY", according to claim 1, comprising the width of the gap (9) being characterized by defining the thickness of the coating of the sand cover layer (7). 7) “MACHINE MANUFACTURING PROCESS FOR MACHINERY”, according to claim 1, understood by the fact of con12 / 21 2/2 around the outer surface (8) of the core (5) is characterized by being completely covered with a layer of sand cover (7) and its mixtures. 8) "MACHINE MAKING PROCESS FOR MACHINERY", according to claim 1, characterized in that the sand covering layer (7) and its mixtures are compact. 9) "MACHINE MAKING PROCESS FOR MACHINERY", according to claim 1, comprising the core (5) being characterized by having its dimension smaller than the internal surface (10) of the mold (1). 10) "MACHINE MAKING PROCESS FOR MACHINERY", according to claim 1, characterized in that the core (5) already covered by a layer of sand cover (7) is a core for machining. 13/21 1/3