Metal casting method

Abstract

The invention discloses a metal casting method, comprising the following steps: under the action of a vacuum pump, a casting mechanism absorbs a melt in a furnace, and keeps the melt from spilling under the action of a vacuum; a liquid supply part of the casting mechanism extends into the inlet of a mold, and the lower end of the liquid supply part enters into a mold cavity; the vacuum degree above the melt in the liquid storage part is adjusted so that the melt flows out from the bottom of the liquid supply part at a required speed, and the height of the liquid supply part is simultaneously increased so that the height of the melt in the mold cavity matches the height of the lower end of the liquid supply part. The invention adopts a laminar flow method for mold filling, thereby reducing turbulence.

Description

Technical Field

[0001] The present invention relates to the field of casting technology, and more particularly to a metal casting method. Background Art

[0002] Metal casting is a method of manufacturing component blanks and one of the basic processes of the modern machinery manufacturing industry. In the casting process, the metal is first smelted into a melt that meets certain requirements, and then poured into a pre-made cavity. After cooling, solidification, and cleaning, a casting with a predetermined shape, size, and mechanical properties is obtained. Casting has the advantages of large process flexibility, low production cost, low equipment investment, and almost no restrictions on the size, shape, and complexity of the structure of the parts, so it is widely used in various types of machinery manufacturing. In the prior art, according to the different materials used to manufacture the cavity, the casting process can be divided into sand casting, lost wax precision casting, gypsum casting, metal mold casting, lost foam casting, etc. Regardless of the process, the metal melt is generally introduced into the cavity through an external gate and an internal gate, and then a high-quality casting is formed through shrinkage compensation of the riser. Obviously, although the design of the external gate and the internal gate can reduce the turbulent flow caused by the melt during the filling process, metal oxidation and turbulence are inevitable in the early stage of pouring. Especially when the casting structure is complex, or when the molten metal is easily oxidized, it is difficult to avoid oxidation and slag inclusion of the molten metal during the filling process. Therefore, laminar flow during molten filling is a relatively ideal state. In industrial practice, processes such as low-pressure casting can achieve the maximum laminar flow, but the equipment investment is large and the process control is complex. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and provide a metal casting method.

[0004] In order to achieve the above object, the present invention adopts the following technical solution:

[0005] The present invention discloses a metal casting method, comprising a mold and a casting mechanism, wherein a mold is provided with a mold cavity, an inlet is provided on the mold, one end of the inlet is connected to the mold cavity, and the other end is connected to the outer periphery of the mold, the casting mechanism comprises a liquid storage part and a liquid supply part connected, the lower part of the liquid storage part is provided with an opening, the upper part of the liquid supply part is connected with a vacuum channel, and the vacuum channel is connected to a vacuum pump;

[0006] The specific steps include:

[0007] Under the action of the vacuum pump, the casting mechanism absorbs the melt in the furnace and keeps the melt from spilling under the action of the vacuum;

[0008] The liquid supply part of the casting mechanism extends into the inlet of the mold, and the lower end of the liquid supply part enters into the mold cavity;

[0009] Adjust the vacuum degree above the melt in the liquid storage part so that the melt flows out from the bottom of the liquid supply part at the required speed, and simultaneously increase the height of the liquid supply part so that the height of the melt in the cavity matches the height of the lower end of the liquid supply part, and the melt is filled in a laminar flow manner;

[0010] The cavity is filled with melt, and the lower end of the liquid supply part rises above the inlet;

[0011] After the melt cools, it is taken out from the mold and the taken out casting is cleaned to complete the casting.

[0012] Furthermore, a riser is provided on the mold, and the riser is communicated with the cavity.

[0013] Furthermore, the mold comprises an upper sand mold and a lower sand mold, and the upper sand mold and the lower sand mold are arranged opposite to each other up and down.

[0014] Furthermore, the mold comprises an upper metal mold and a lower sand mold, and the upper metal mold and the lower sand mold are arranged opposite to each other up and down.

[0015] Furthermore, the liquid storage part and the liquid supply part are made of ceramics.

[0016] The beneficial effects of the present invention are as follows: as the melt is released, the position of the casting mechanism is gradually raised to ensure the laminar flow of the melt, thereby greatly reducing defects such as slag inclusion caused by turbulence. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The casting steps in this embodiment are shown in FIG. Figure 1 ;

[0018] Figure 2 The casting steps in this embodiment are shown in FIG. Figure 2 ;

[0019] Figure 3 The casting steps in this embodiment are shown in FIG. Figure 3 ;

[0020] Figure 4 The casting steps in this embodiment are shown in FIG. Figure 4 .

[0021] Figure numerals: 1. sand box; 2. mold; 3. cavity; 4. inlet; 5. sand core; 6. casting mechanism; 7. liquid storage part; 8. liquid supply part; 9. vacuum channel. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] A metal casting method includes a sand box 1, a mold 2 and a casting mechanism 6, wherein the mold 2 is installed in the sand box 1, a cavity 3 is provided in the mold 2, a sand core 5 can be placed in the cavity 3, an inlet 4 is provided on the mold 2, one end of the inlet 4 is connected to the cavity 3, and the other end is connected to the periphery of the mold 2, and the casting mechanism 6 includes a liquid storage part 7 and a liquid supply part 8 that are connected, the lower part of the liquid storage part 7 is opened, and the upper part of the liquid supply part 8 is connected to a vacuum channel 9, and the vacuum channel 9 is connected to a vacuum pump.

[0024] like Figure 1-Figure 4 As shown, a metal casting method comprises the following steps:

[0025] The casting mechanism 6 enters the furnace, and the lower end of the liquid supply part 8 is inserted into the melt in the furnace. Under the action of the vacuum pump, the melt is sucked into the liquid supply part 8 and the liquid storage part 7. After sucking a sufficient amount of melt, the casting mechanism 6 rises and leaves the furnace. Under the action of the vacuum, the melt in the casting mechanism 6 is kept from spilling.

[0026] After the casting mechanism 6 reaches above the mold 2 , the casting mechanism 6 is controlled to descend so that the liquid supply part 8 of the casting mechanism 6 extends into the inlet 4 , and the lower end of the liquid supply part 8 can enter the cavity 3 and approach the bottom of the cavity 3 .

[0027] The vacuum degree above the melt in the liquid storage part 7 is adjusted so that the melt flows out from the bottom of the liquid supply part 8 into the cavity 3 at the required speed. At the same time, the height of the liquid supply part 8 is simultaneously increased so that the height of the melt in the cavity 3 matches the height of the lower end of the liquid supply part 8. Specifically, the height of the lower end of the liquid supply part 8 is 0-2 cm higher than the height of the melt in the cavity 3, so that the melt can be filled in a stable laminar flow manner. In the traditional gate system, the discharge height of the melt is a certain distance from the height of the melt in the cavity, and turbulence is inevitable in the early stage of casting. The laminar flow filling method can reduce the turbulence generated by the traditional gate system, and is particularly suitable for metal melts that are sensitive to turbulence, such as magnesium alloys and aluminum alloys, and can reduce defects such as slag inclusions caused by turbulence.

[0028] When all the melt in the liquid storage part 7 and the liquid supply part 8 enters the cavity 3, the cavity 3 is filled with the melt. At this time, the lower end of the liquid supply part 8 rises above the inlet 4 and can move freely without causing interference.

[0029] Wait for a period of time to allow the melt in the mold 2 to cool completely. Take the casting out of the mold 2, and clean the taken-out casting to complete the casting.

[0030] It requires little change to the traditional casting method and can effectively realize precise control of the filling process, thereby improving the filling capacity of the molten metal. The entire operation is simple and easy, saving production costs, and the quality of the castings has been significantly improved.

[0031] Furthermore, a riser is provided on the mold 2, and the riser is connected with the cavity 3, and the melt can be added to the riser to compensate for shrinkage.

[0032] Furthermore, the casting method can be used for sand casting. When used for sand casting, the mold 2 includes an upper sand mold and a lower sand mold, and the upper sand mold and the lower sand mold are arranged opposite to each other up and down.

[0033] Furthermore, the casting method can also be used for metal mold gravity casting. When used for metal mold gravity casting, the mold 2 includes an upper metal mold and a lower sand mold, and the upper metal mold and the lower sand mold are arranged opposite to each other up and down.

[0034] Furthermore, the liquid storage part 7 and the liquid supply part 8 in the casting mechanism 6 that are in contact with the melt can be made of ceramic or metal. The selection criteria include minimizing reaction with the metal melt and minimizing heat dissipation to ensure that the melt maintains its original temperature as much as possible during the transmission process.

[0035] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A metal casting method, characterized in that: The invention comprises a mold (2) and a casting mechanism (6), wherein a mold cavity (3) is arranged in the mold (2), an inlet (4) is arranged on the mold (2), one end of the inlet (4) is connected to the mold cavity (3), and the other end is connected to the outer periphery of the mold (2), the casting mechanism (6) comprises a liquid storage part (7) and a liquid supply part (8) which are connected, the lower part of the liquid storage part (7) is opened, the upper part of the liquid supply part (8) is connected to a vacuum channel (9), and the vacuum channel (9) is connected to a vacuum pump; The specific steps include: Under the action of the vacuum pump, the casting mechanism (6) absorbs the melt in the furnace and keeps the melt from spilling under the action of the vacuum; The liquid supply part (8) of the casting mechanism (6) extends into the inlet (4) of the mold (2), and the lower end of the liquid supply part (8) enters into the mold cavity (3); The vacuum degree above the melt in the liquid storage part (7) is adjusted so that the melt flows out from the bottom of the liquid supply part (8), and the height of the liquid supply part (8) is simultaneously increased so that the height of the melt in the mold cavity (3) matches the height of the lower end of the liquid supply part (8), and the melt is filled in a laminar flow manner; The cavity (3) is filled with melt, and the lower end of the liquid supply portion (8) rises above the inlet (4); After the melt is cooled, it is taken out from the mold (2), and the taken out casting is cleaned to complete the casting.

2. A metal casting method according to claim 1, characterized in that: The mold (2) is provided with a riser, which is connected to the mold cavity (3).

3. A metal casting method according to claim 2, characterized in that: The mold (2) comprises an upper sand mold and a lower sand mold, and the upper sand mold and the lower sand mold are arranged opposite to each other up and down.

4. A metal casting method according to claim 2, characterized in that: The mold (2) comprises an upper metal mold and a lower sand mold, and the upper metal mold and the lower sand mold are arranged opposite to each other up and down.

5. A metal casting method according to claim 1, characterized in that: The liquid storage part (7) and the liquid supply part (8) are made of ceramics.

Images