CN101323015B - The Metal Mold Rotary Casting Technology Using Composite Punch Type Pressurized Heat-preservation Casting Riser - Google Patents

Abstract

A metal mold rotating casting technique which adopts a compound punch pressurizing heat-preservation casting cap is characterized in that a casting method includes: (1) the metal mold is pre-heated in a box-shaped electric furnace and is arranged on a rotating casting machine after being sprayed with dye; (2) molten metal is slowly poured into a mold cavity during the turning process of the metal mold; (3) the compound punch pressurizes the molten metal in the opening of the casting cap to lead the molten metal in the opening of the casting cap to generate extrusion and filtration effect under the action of pressure so as to feed a casting. Compared with the traditional metal mold casting technique, the metal mold rotating casting technique has the advantages of: high exhaust function of a compound punch pressurizing heat-preservation casting cap system, good feeding effect, greatly reducing the defects of the casting, greatly improving the quality of the casting and simultaneously achieving the goals of solving the problem of exhaust and feeding.

Description

The Metal Mold Rotary Casting Technology Using Composite Punch Type Pressurized Heat-preservation Casting Riser

technical field

The invention relates to a metal mold casting process, in particular to a metal mold rotary casting process using a composite punch type pressurized and heat-preserving pouring riser.

Background technique

In the traditional metal mold casting process, venting and feeding have always been the focus and difficulty of casting process design; the reasons are: (1) The metal mold wall itself cannot vent, and its venting problem is much more complicated than that of sand casting ;During the casting process, the setting position of the riser and the exhaust groove, especially the choice of the filling method, may cause poor exhaust of the cavity, making it easy to form pores in the casting; this is especially true for complex castings; (2 ) feeder to the casting basically depends on gravity, and it is easy to cause shrinkage cavity and shrinkage porosity due to insufficient feeding, especially the probability of casting defects in thick and large castings is greater; or the pouring riser should be designed to have a large volume (3) Exhaust and feeding are still a pair of opposite contradictions; for example: the bottom injection type exhausts well, but the feeding function is poor; the top injection type has good shrinkage function, but the exhaust function is poor Poor, resulting in poor casting quality.

Contents of the invention

The object of the present invention is to provide a metal mold rotary casting process using a compound punch type pressurized heat preservation pouring riser. The metal mold rotary casting process has good bottom injection exhaust and feeding function.

The present invention is achieved in this way, its composite punch type pressurized heat preservation pouring device is mainly composed of a pouring riser and a composite punch, the pouring riser is similar to a honeycomb, and is divided into an insulation layer and an inner chamber, and the composite punch is mainly composed of a sealing punch It is composed of head, extrusion punch and spring, and its feature is that the pouring method is as follows: (1) The small and medium-sized metal molds are preheated in a box-shaped electric furnace, the preheating temperature is 200-300°C, and then installed on the rotary casting machine after spraying paint. When the composite punch is installed, the gap between the punch and the sealing flange of the pouring riser should not exceed 0.05mm, and the gap between the parting surface should be within 0.05mm; after the large metal mold is installed on the rotary casting machine, it is directly heated and sprayed with paint; (2) Before pouring, according to the characteristics of different castings, the metal mold is pre-tilted at a certain angle after closing the mold. The alloy liquid is slowly poured into the cavity during the rotation of the metal mold. It should be poured quantitatively. The alloy liquid should not cross the bottom line of the sealing flange, so as to be lower than the sealing method. The blue bottom line is preferably 3-5mm; in order to avoid the alloy liquid from dripping on the edge of the sealing flange during the casting process, a sprue cup is used during pouring and removed after pouring; in order to ensure a stable filling process and facilitate gas discharge, the metal mold The speed of rotation should not be too fast; (3) When the metal mold stops rotating, the pouring and riser are aligned with the composite punch, and the periphery of the pouring riser begins to solidify and crust, and the center is still in a liquid state, the composite punch immediately presses against the molten metal in the pouring riser. Pressurize, so that the molten metal in the riser will squeeze and filter under the action of pressure to feed the casting; the specific pressure range: 2-30Mpa, after holding the pressure for 1-3 minutes, open the mold and take out the casting.

The invention has the advantages that: compared with the traditional metal mold casting process, the composite punch type pressurized heat preservation pouring system has strong exhaust function, good shrinkage effect, greatly reduced casting defects and greatly improved quality. The purpose of simultaneously solving exhaust and feeding is achieved.

Description of drawings

Fig. 1 is a structural schematic diagram of the composite punch type pressurized heat preservation pouring device of the present invention.

Detailed ways

As shown in Fig. 1, the composite punch type pressurized and heat-preserved pouring device of the present invention is mainly composed of a pouring riser and a composite punch. The pouring riser is similar to a honeycomb, and is divided into an insulation layer and an inner chamber 2. It is formed by filling the round hole of the metal skeleton 4, the thickness of the insulation layer is not less than 30mm, and the gap after the parting surface is closed is not more than 0.05mm; the roughness of the inner chamber is 1.6--3.2, and it is equipped with a composite punch The metal frame 4 is made of hot work die steel. In order to enable the inner chamber 2 to withstand a larger specific pressure, the minimum thickness of the metal frame should not be less than 3mm; the metal frame and the circle filled with thermal insulation material The pore volume ratio is 30-40%, and the insulation material can be aluminum silicate fiber cotton or calcareous insulation material; in this way, the entire riser is both pressure-resistant and heat-resistant; for general castings, the riser can also be larger than the traditional design volume 15% smaller. According to the different characteristics of the casting, the pouring riser can also be designed as one, and some parts can also be provided with risers in multiple positions; the composite punch is mainly composed of a sealing punch 5, an extrusion punch 7 and a spring 6. The sealing punch and extrusion punch are made of hot work die steel; when the composite punch starts to apply pressure, the sealing punch first presses the sealing flange of the pouring riser, and the composite punch continues to go down, under the action of the spring force , the sealing punch presses the sealing flange of the riser tighter and tighter, which can ensure that the molten metal 1 in the riser does not spray out; under the continuous action of external force, the extrusion punch 7 is pressed against the molten metal in the center of the riser 1 Extrusion (specific pressure is 5-30Mpa). After holding the pressure for several minutes, the extrusion punch is pulled out from the casting and goes up to a certain height. The fixed bracket 9 drives the guide rod 8, and the guide rod drives the sealing punch to go up together. Spray the paint on the punch.

The pouring process steps are:

1. Small and medium-sized metal molds can be preheated in a box-shaped electric furnace (the preheating temperature is generally 200-300°C), and installed on the rotary casting machine after spraying paint. Make sure that the composite punch is installed on the punch and the riser to seal the flange The fit gap is not greater than 0.05mm, and the parting surface gap should be within 0.05mm; large metal molds can be installed on the rotary casting machine and then directly heated and sprayed with paint.

2. Before pouring, according to the characteristics of different castings, the metal mold is pre-tilted at a certain angle after closing the mold. The alloy liquid is slowly poured into the cavity during the rotation of the metal mold. It should be poured quantitatively. The alloy liquid should not cross the bottom line of the sealing flange, so as to be lower than The bottom line of the sealing flange is preferably 3-5mm; in order to avoid the alloy liquid from dripping on the edge of the sealing flange during casting, it is best to use a sprue cup during pouring and remove it after pouring; in order to ensure a stable filling process and facilitate gas Discharge, the rotation speed of the metal type should not be too fast (generally complete the rotation within 1-3 minutes).

3. When the metal mold stops rotating, the pouring and riser are aligned with the compound punch, and the periphery of the pouring riser begins to solidify and crust, and the center is still liquid, the compound punch immediately pressurizes the metal liquid in the pouring riser to make the pouring riser The molten metal in the casting is squeezed and filtered under the action of pressure to feed the casting; the specific pressure range: 2-30Mpa, after holding the pressure for 1-3 minutes, open the mold and take out the casting.

Claims (1)

1. metal mold rotary casting technology that adopts compound punch type pressure heat-preserving to water to emit, its compound punch type pressure heat-preserving waters and emits device mainly to be made up of dead head and compound punch, the similar honeycomb of dead head, divide heat-insulation layer and inner room, compound punch is mainly by sealing punch, extruding drift and spring are formed, and it is characterized in that the pouring technology step is:

(1) middle-size and small-size metal mold preheating in the box-shaped electric furnace, preheat temperature is 200-300 ℃, be installed to behind the spray paint on the rotated mold filing machine, when compound punch is installed, drift and dead head sealing flange fit clearance are not more than 0.05mm, the die joint gap should be in 0.05mm, and large-scale metal mold is installed to the direct hot spraying material in back on the rotary casting machine;

(2) before the cast, make behind the metal mold matched moulds to tilt in advance, alloy liquid slowly pours into die cavity in the metal mold turning course, answer quantitative casting, and alloy liquid is not crossed the sealing flange bottom line, is advisable to be lower than sealing flange bottom line 3-5mm; Alloy liquid droplet drops on the sealing flange limit in the casting cycle in order to avoid, and adopts cup during cast, removes after having watered;

(3) stop the rotation when metal mold, dead head aligns with compound punch, the dead head periphery begins to solidify crust, when the center is still liquid, compound punch makes the molten metal in the dead head produce crowded filter effect under pressure and the feeding foundry goods, specific pressure scope: 2-30MPa immediately to molten metal pressurization in the dead head, after dwell time 1-3 minute, foundry goods is taken out in die sinking.

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