TW200539968A - Vacuum lost form casting method - Google Patents

Abstract

This invention provides a vacuum lost form casting method, including the steps of: placing a foaming plastic material into a metal die; foaming the material into the desired model and then dipping the same into a coating that is curing to form a thin film over the surface of the model after drying; placing the model having a curing thin film over its surface into a sand box; burying the model into the sand box by impelling and vibrating modeling sand; covering the top opening of the sand box with a plastic film layer; connecting a vacuum pump to the sand box and injecting a molten metal to burn or directly oxidize the model via the molten metal; removing air and water vapor from the sand box due the suction of the vacuum pup; maintaining the molten meal at an optimum fluidity; and pouring out the modeling sand in the sand box after the molten metal is solidified after cooling so as to obtain the metal casting.

Description

200539968 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention is to provide a method for μ 、, which refers to a method for casting scales that does not require a drafting process and scale washing process, especially =: saving by f Casting man-hours to improve the quality of castings [Previous technology] ^ According to the general tradition of prayer, wood ^ molding sand is properly lowered in the sand box, and the sand 1; two mold: put in the already filled in, and The model is placed in the second sand box; ::! :: The above are used in combination with m ^ ah ^ ^ ^ ^ m ^ I. After the fork type is placed, the constructor will fill it in a wonderful way. The face of Shangsha Ming ^, ^, Tango / phase will completely bury the chess pattern in the molding sand. In the course of the disaster, the constructor needs to make the molding sand tightly. G 士士 4 uIί Fill in the second sand box and need to dig the runner. Second, the ventilation hole. After the filling of the molding sand is completed, the constructor needs to take the second sand box 2: take out the model (draft). At this time, the edge of the mold cavity will collapse during the process of removing the model (draft). Even if it is repaired, it may still leave defects and cause inaccuracy in accuracy. After removing the model (draft), Return the cut-away model in place and wash and cast. During washing and casting, it is to pour the metal in a high temperature molten state into the cavity made of molding sand in the sand box, so that the metal is cooled and solidified after the washing and casting is completed. The scales buried in the mold can be taken out. However, during the above-mentioned casting process, the high-temperature molten metal may cause the edge of the cavity to collapse when flowing, or the water vapor in the molding sand may be evaporated to form water vapor due to high temperature. Has a bad effect on the casting, which in turn leads to defective products. [Summary of the Invention] You Jian 1 is cumbersome in the traditional town manufacturing method in manufacturing, and its casting precision and quality are difficult to control. It is not enough for modern industry to pursue precision, quality and reduction.

200539968

The need for the method, the need for the cost of the package, there is actually a research and development of a more practical casting method. The present invention is to provide a vacuum lost foam casting method including: (a) first put the foamed plastic material into a metal mold, and Use steam heating to foam the foamed plastic material into the required model. (B) Then completely immerse the newly foamed model in the coating agent, so that the coating agent is evenly coated on the surface of the model. A hardened thin layer is formed on the surface; (C) The model with the hardened thin layer on the surface is placed in a sand box. In addition to the opening at the top, the sand box is provided with a connection port on one side of the sand box. Sand blasting and vibration are used to fill the molding sand, so that the model with a hardened thin layer is buried in the sand box; (d) Cover the top opening of the sand box with a plastic film layer, and only the side of the sand box is left with (E) The vacuum pump is connected to the sand box's interface and filled with molten metal. The model is burned or directly oxidized through the molten metal at a high temperature, and at the same time, the vacuum pump is used. Attract air and water vapor in the sand box And the suction holding preferred flowability (f) After the molten metal to be cooled and solidified into a solid, the flask was decanted molding sand i.e. metal cast molten metal can be removed through the vacuum pump. In this way, the present invention does not need to take out the model in the steps, so there is no collapse of the mold cavity edge during the casting process, and during the casting process, the present invention uses a vacuum pump to access the hole from the sand box. Lieutenant in the sand box

Page 6 200539968 V. Description of the invention (3)

The air between the steam and the molding sand is sucked out, so that it can avoid the high temperature melting into the casting properties of the flowing properties of the high temperature molten metal, and also save man-hours f, so that the inside of the sand box becomes a vacuum-like molten metal to produce oxidation, At the same time, it can be increased to obtain a practical benefit with high accuracy, high quality, and reduced manufacturing costs. [Embodiment] The right-checking committee member can further understand the features, functions, and functions of the present invention. Ιν π 4 / V Α 月 b 朽 明】 Details are as follows: Please refer to the following [Schematic Brief First, please refer to the vacuum lost foam casting method shown in Figure 1, which includes:

The present invention is to provide (a) the foamed plastic material (70) is first placed in a metal mold (10) and heated on the basis to heat the foamed plastic material (70) into a desired model. (20) After (), the model (20) that has just been foamed is completely immersed in the smearing agent, so that the smearing agent is evenly coated on the surface of the model (20). After the model (20) is dried, it will form on the surface. Hardened thin layer (21); (0) The model (20) with the hardened thin layer (21) on the surface is placed in a sand box (3). The sand box (3 0) is There is another connection port (31) on one side of the sand box, and the sand is filled by sand blasting and vibration.

(40) 'so that the model (20) with a hardened thin layer (21) is buried in the sand box (30); (d) and covered with a plastic film layer (41) in the sand box (30) The top of the sand box is open, and only the side of the sand box (30) is provided with a connection port (31) for a sand blocking ventilation net (32).

Page 7 200539968 V. Description of the invention (4) (e) The vacuum pump (50) is connected to the opening (31) of the sand box (30) and molten metal is poured. The molten metal is passed through the high temperature to make the model (20) Combustion or direct oxidation, at the same time, the air and water vapor in the flask (30) are sucked out by the suction of the vacuum pump (50), and the molten metal is maintained by the suction of the vacuum pump (50) Better fluidity; (0) After the molten metal has cooled and solidified into a solid, the molding sand (40) in the sand box (30) is poured out to take out the metal casting (60). By doing this, when the present invention is put into practical use Since the model (20) does not need to be taken out in the step, there will be no collapse of the mold cavity edge during the casting process

In the casting process, the present invention uses a vacuum pump (50) to remove the water vapor in the sand box (30) and the molding sand (40) from the connection hole (31) of the sand box (30). The air is sucked out, and then the inside of the sand box (30) is brought into a vacuum state. Ί = The: Warm molten metal is oxidized, and at the same time, the fluidity can be improved to obtain-with high precision and high quality. ^ ^ Practical benefits to reduce manufacturing costs. '' J 文 系 for the age of this creation yf 去 杳 "#. ^ ^ ^ ^ ^ ^ ^ Bg. The preferred embodiment is based on the technical characteristics of this creation. Those who are skilled in this technology should not depart from this work. Under the spirit and principles of this article, make changes to this creation, while changes and modifications should be covered by & τ ± 仃 wenwen changes and modifications, and these changes% 3 are covered in the following

Page 8 200539968 Brief Description of Drawings [Simple Description of Drawings] Figure 1 is a manufacturing flow chart of the present invention.

[Description of component symbols] (10) Metal mold (20) Model (21) Hardened thin layer (30) Sand box (31) Interface (32) Sand blocking and ventilating net (40) Molding sand (41) Plastic film layer (50 ) Vacuum pump (60) Metal casting (70) Foamed plastic material

Claims (1)

200539968 A vacuum lost foam casting method includes: (a) first placing a foamed plastic material into a metal mold, and heating the foamed plastic material to a desired model by steam heating; (b) then setting the hair The finished model is completely immersed in the coating agent, so that the coating agent is evenly coated on the surface of the model, and a hardened thin layer is formed on the surface after the model is dried; (c) the model with the hardened layer on the surface is placed in the sand box In addition to the opening at the top, the flask is provided with a connection port on one side of the flask. 'Fill the sand with sand blasting and vibration, so that the model with the hardened layer is buried in the sand box; (d) Cover the top opening of the sand box with a plastic film layer, leaving only the sand box The side is equipped with a connection port for sand-blocking and ventilating mesh; (e) The vacuum pump connection group is then placed at the connection port of the sand box and molten metal is poured, and the model is burned or directly oxidized through the high-temperature molten metal, and at the same time, by The suction of the vacuum pump sucks out the air and water vapor in the sand box, and the molten metal maintains a better fluidity through the suction of the vacuum pump (f) After the molten metal cools and solidifies into a solid, it is poured out of the sand box. Sand casting can remove the metal casting. Page 10