Dynamic solidification pouring system for investment casting and use method of dynamic solidification pouring system

Abstract

The invention relates to a dynamic solidification pouring system for investment casting, which comprises a die head and a plurality of die shell structures arranged around the die head, and the die head is matched with the die shell structures; the die head comprises a pouring column body, an exhaust structure is arranged on the upper portion of the pouring column body, and a spiral auxiliary pouring gate is arranged on the lower portion of the pouring column body. The mold shell structure comprises a product pouring inner cavity, an upper connecting port is formed in the top of the mold shell structure, and a lower pouring channel is formed in the bottom of the mold shell structure. When the pouring system is used, dynamic solidification pouring of molten metal can be achieved, after the molten metal enters the pouring system, the molten metal enters the product pouring inner cavity along the spiral auxiliary pouring gate under the action of centrifugal force, then solidification is completed layer by layer along the inner wall of the mold shell, metal of each layer is solidified in sequence, mold filling can be completed stably and rapidly, and the production efficiency is improved. And the mold filling speed is increased, the probability of insufficient pouring and cold shut of the thin-wall metal part is reduced, and the product quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of investment casting, in particular to a dynamic solidification pouring system for investment casting and a method of using the same, and more particularly to a pouring system capable of realizing dynamic solidification and a method of using the same. Background Art

[0002] At present, the investment casting process is a near-net-shape casting process with high dimensional accuracy. The products produced by the process require little or no processing and have been widely used in recent years.

[0003] In actual production, the pouring system of investment casting is often more complicated. Especially when it is necessary to produce products with higher quality requirements, there will be problems such as too many product pouring and risers, and the pouring system is too complicated, which can easily lead to disordered flow of molten metal, low yield, low production efficiency and high cost.

[0004] Therefore, the market is in urgent need of a simpler pouring system to reduce production costs while ensuring output rate. Summary of the invention

[0005] The object of the present invention is to provide an improved dynamic solidification pouring system for investment casting and a method of using the same. Through structural improvements and method innovations, rapid filling can be achieved, layered solidification can be achieved in the product pouring cavity, the filling capacity of the molten metal is improved, and product quality and output rate are improved.

[0006] In order to achieve the above-mentioned purpose, the technical solution of the present invention is: a dynamic solidification pouring system for investment casting, characterized in that: the pouring system includes a die head and a plurality of mold shell structures arranged around the die head, and the die head and the mold shell structure cooperate with each other; the die head includes a pouring column, the upper part of the pouring column is provided with an exhaust structure, and the lower part is provided with a spiral auxiliary runner; the mold shell structure includes a product pouring cavity, the top of the mold shell structure is provided with an upper connecting port, and the bottom of the mold shell structure is provided with a lower pouring channel.

[0007] Preferably, the exhaust structure includes a circular exhaust chassis, and the exhaust chassis is connected to the casting column through a plurality of exhaust ribs, and the exhaust ribs are in an arc shape.

[0008] Furthermore, the upper part of the casting column is an inverted cone-shaped pouring cup, one end of the exhaust rib is connected to the outside of the pouring cup, and the other end is connected to the exhaust chassis through a raised guide portion, the guide portion cooperates with the upper connection port of the mold shell structure, and the exhaust rib and the mold shell structure are arranged one by one.

[0009] Furthermore, the spiral auxiliary pouring channel includes a cylindrical outer shell, in which a plurality of rotating blades are evenly distributed, one end of the rotating blades is connected to the casting column, and the other end is connected to the inner wall of the cylindrical outer shell.

[0010] Furthermore, one end of the rotating blade connected to the casting column is the liquid inlet end, and the other end is the liquid outlet end. The ratio of the cross-section of the liquid inlet end to the cross-section of the liquid outlet end is 1.5-3:1. The number of rotating blades corresponds to the number of mold shell structures, and the mold shell structure is connected to the rotating blades through the lower casting channel.

[0011] A method for using a dynamic solidification pouring system for investment casting, characterized in that: a. assembling a plurality of mold shell structures around a die head, and the die head is mounted on a centrifuge; b. starting the centrifuge to rotate slowly, accelerating from 5-10 rpm to 10-30 rpm, and introducing molten metal into the pouring system along a pouring cup; c. accelerating the centrifuge to 250-350 rpm, and after entering the pouring system, the molten metal enters the product pouring cavity of the mold shell structure along a spiral auxiliary runner under the action of centrifugal force, and solidifies layer by layer against the mold shell, and each layer of metal solidifies sequentially, completing the filling of the mold quickly and smoothly; d. after the product filling is completed, the molten metal stops pouring, and the centrifuge continues to rotate until the molten metal is completely solidified, and then the centrifuge stops rotating to complete the pouring work.

[0012] Compared with the prior art, the technical solution of the present invention not only improves the overall technical solution, but also includes many improvements in details. Specifically, it has the following beneficial effects: 1. The improved scheme of the present invention is that the pouring system includes a die head and a plurality of mold shell structures arranged around the die head, and the die head and the mold shell structure cooperate with each other; the die head includes a pouring column, and the upper part of the pouring column is provided with an exhaust structure, and the lower part is provided with a spiral auxiliary runner; after entering the pouring system, the molten metal enters the product pouring cavity of the mold shell structure along the spiral auxiliary runner under the action of centrifugal force, and solidifies layer by layer against the mold shell, and each layer of metal solidifies sequentially, which greatly weakens the shrinkage compensation effect of the pouring riser, can reduce the number of gates, simplify the pouring structure, and can quickly, smoothly and accurately complete the filling, thereby improving the product quality; 2. In the technical solution of the present invention, the exhaust structure includes a circular exhaust chassis, and the exhaust chassis is connected to the casting column through a plurality of exhaust ribs, and the exhaust ribs are in an arc shape; when the molten metal is filled from bottom to top under the action of centrifugal force, the original air in the product casting cavity will be squeezed to the uppermost layer of the casting system, and discharged from the casting system through the exhaust structure, thereby reducing air resistance and increasing the filling speed; 3. In the structure of the present invention, the spiral auxiliary runner includes a cylindrical shell, and a plurality of rotating blades are evenly distributed in the cylindrical shell. The spiral auxiliary runner enables the molten metal to fill the mold smoothly and quickly, thereby increasing the filling speed, reducing the probability of defects such as insufficient pouring and cold shut of thin-walled metal parts, and improving product quality; 4. The present invention has a simple structure, reasonable layout, low cost, simple casting process, improved efficiency and finished product quality, reduced metal liquid usage, saved cost, and is easy to promote and utilize. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the present invention.

[0014] Figure 2 It is a schematic diagram of the die structure of the present invention.

[0015] Figure 3 It is a structural schematic diagram of the formwork structure of the present invention.

[0016] Reference numerals: 1 die head, 2 mold shell structure; 11 casting column, 12 exhaust structure, 13 spiral auxiliary pouring channel; 21 product pouring inner cavity, 22 upper connection port, 23 lower pouring channel; 111 pouring cup; 121 exhaust chassis, 122 exhaust ribs, 123 guide portion; 131 is a housing, 132 is a rotating blade. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. 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.

[0018] The present invention provides a dynamic solidification pouring system for investment casting, see Figure 1 The difference between the present invention and the prior art lies in that: the pouring system comprises a die head 1 and a plurality of mold shell structures 2 arranged in sequence around the die head, the die head and the mold shell structure cooperate with each other so that the molten metal entering from the upper part of the die head can enter the mold shell structure along the die head structure; the die head comprises a pouring column 11, the upper part of the pouring column is provided with an exhaust structure 12 for discharging the gas during the pouring process, and the lower part is provided with a spiral auxiliary runner 13 that allows the molten metal to smoothly and quickly enter the mold shell structure; the mold shell structure comprises a product pouring cavity 21, the top of the mold shell structure is provided with an upper connecting port 22, and the bottom of the mold shell structure is provided with a lower pouring channel 23, where the upper connecting port and the lower pouring channel are both connected to the die head.

[0019] When in use, the pouring system of the present invention can realize dynamic solidification pouring of molten metal. After the molten metal enters the pouring system, it enters the product pouring cavity along the spiral auxiliary runner under the action of centrifugal force, and then solidifies layer by layer along the inner wall of the mold shell, so that each layer of metal is solidified sequentially, and filling can be completed smoothly and quickly, thereby improving the filling speed, reducing the probability of insufficient pouring and cold shut of thin-walled metal parts, and improving product quality.

[0020] Example 1

[0021] The present invention discloses a dynamic solidification pouring system for investment casting, comprising a die head 1 and a mold shell structure 2 arranged around the die head. The number of the mold shell structures is generally 3-7. In this embodiment, 5 mold shell structures are evenly distributed around the die head. The die head and the mold shell structure cooperate with each other so that the molten metal entering the pouring system can flow smoothly and quickly into the mold shell structure along the die head. The die head here comprises a pouring column 11, the upper part of the pouring column is provided with an exhaust structure 12, the lower part is provided with a spiral auxiliary pouring channel 13, and the top of the pouring column is provided with a pouring port; the mold shell structure comprises a product pouring inner cavity, the product pouring inner cavity is a smooth arc-shaped inner wall, the top of the mold shell structure is provided with an upper connection port, and the bottom of the mold shell structure is provided with a lower pouring channel.

[0022] Specifically, the exhaust structure includes a circular exhaust chassis 121, which is sleeved on the outside of the casting column. The exhaust chassis and the casting column are connected by five exhaust ribs 122, and the exhaust ribs are in the shape of an arc protruding outward. The exhaust ribs can exhaust air during the filling process of the molten metal, reduce air resistance, and increase the filling speed, thereby achieving smooth filling and increasing the strength of the casting system, ensuring that the module is not damaged during the shell making process.

[0023] Further, the upper part of the pouring column is a pouring cup 111 in the shape of an inverted cone, the top of the pouring cup is a pouring channel, the upper end of the exhaust rib is connected to the outside of the pouring cup, the upper end is connected to the pouring cup at 2 / 3 of the height, and the lower end is connected to the exhaust chassis through a raised guide portion 123, the guide portion is matched with the upper connection port of the mold shell structure, and the upper connection port is provided with a slot matched with the guide portion, so that the mold shell structure and the exhaust rib are arranged one by one. The upper port of the exhaust rib here is smaller than the lower port, and the ratio of the diameter of the upper port to the lower port is 1:1.05--1.085, preferably 1:1.068, and further squeezing the space is conducive to smooth and efficient exhaust. Further, after entering the pouring system, the molten metal enters the product pouring cavity of the mold shell structure along the spiral auxiliary runner under the action of centrifugal force, and solidifies layer by layer against the mold shell, so an angle is also set between the exhaust rib and the bottom exhaust chassis, and the angle is 65-70 degrees, further utilizing the effect of centrifugal force to facilitate exhaust. Furthermore, after the mold shell structure is installed, the height of the guide portion is higher than the height of the upper connection port 22 by 1.2-2 mm.

[0024] The spiral auxiliary runner includes a cylindrical outer shell 131, and a plurality of rotating blades 132 are evenly distributed in the cylindrical outer shell. One end of the rotating blade is connected to the casting column, and the other end is connected to the inner wall of the cylindrical outer shell. One end of the rotating blade connected to the casting column is the liquid inlet end, and the other end is the liquid outlet end. The cross section of the liquid inlet end is larger than the cross section of the liquid outlet end. Further, the ratio of the cross section of the liquid inlet end to the cross section of the liquid outlet end is 1.5-3:1, preferably 2.5:1. The number of rotating blades corresponds to the number of mold shell structures, and the mold shell structure is connected to the rotating blades through the lower casting channel. After the molten metal enters the casting system, it enters the inner cavity of the product along the spiral auxiliary runner under the action of centrifugal force. In this way, the molten metal can complete the filling smoothly and quickly, which improves the filling speed, reduces the probability of insufficient pouring and cold shut of thin-walled metal parts, and improves product quality.

[0025] The molten metal in the pouring system is filled from bottom to top under the action of centrifugal force, and the original air in the mold cavity is squeezed to the top layer of the pouring system, and discharged from the pouring system through the exhaust ribs, thereby reducing the filling resistance, increasing the filling speed, and reducing the probability of cold shut and insufficient pouring. In addition, the exhaust structure and product play a role in reinforcing the pouring system, solving the problem of broken shells during the shell making process when the investment casting is used to make "heavy weight modules". The heavy weight modules here refer to thin-walled workpieces with a large price ratio. The conventional tree assembly method can only assemble 2-3 workpieces in one module, and the investment casting centrifugal tree assembly scheme of the present invention can reach 5-7 workpieces in one module, which improves the material yield of the workpiece and improves production efficiency.

[0026] Example 2

[0027] In this embodiment, a method for using a dynamic solidification pouring system for investment casting is provided, and the steps of the method are as follows: a. assemble several mold shell structures around the die head, and the die head is installed on a centrifuge; b. start the centrifuge to rotate slowly, 5-30 rpm, and introduce the molten metal into the pouring system along the pouring cup; c. accelerate the centrifuge to 250-350 rpm, and after entering the pouring system, the molten metal enters the product pouring cavity of the mold shell structure along the spiral auxiliary pouring channel under the action of centrifugal force, and solidifies layer by layer against the mold shell, and each layer of metal solidifies sequentially, and the filling is completed quickly and smoothly; d. After the product filling is completed, the molten metal stops pouring, and the centrifuge continues to rotate until the molten metal is completely solidified, and then the centrifuge stops rotating to complete the pouring work. After the molten metal enters the pouring system, it enters the product cavity along the spiral auxiliary pouring channel under the action of centrifugal force. In this way, the molten metal can complete the filling smoothly and quickly, improve the filling speed, reduce the probability of insufficient pouring and cold shut of thin-walled metal parts, and improve product quality.

[0028] Specifically, in step c, an exhaust structure is provided on the upper part of the casting column, and the exhaust structure includes a circular exhaust chassis, which is connected to the casting column through a number of exhaust ribs, and the exhaust ribs are in the shape of an arc; when the molten metal is filled from bottom to top under the action of centrifugal force, the original air in the product casting cavity will be squeezed to the top layer of the casting system and discharged from the casting system through the exhaust structure. At the same time, the air resistance is reduced, the filling speed is increased, so that smooth filling can be achieved and the strength of the casting system can be increased, ensuring that the module is not damaged during the shell making process.

[0029] In step c, during pouring, the molten metal enters the product pouring cavity under the action of centrifugal force and solidifies in layers along the outer wall, solidifying from the outer layer to the inner layer. This weakens the shrinkage compensation effect of the pouring and riser in the conventional investment casting process, reduces the placement of the pouring gate, improves the yield, improves production efficiency, and reduces costs.

[0030] In step c, the spiral auxiliary runner includes a cylindrical outer shell, and a plurality of rotating blades are evenly distributed inside the cylindrical outer shell, one end of the rotating blade is connected to the casting column, and the other end is connected to the inner wall of the cylindrical outer shell; one end of the rotating blade connected to the casting column is the liquid inlet end, and the other end is the liquid outlet end, and the cross-section of the liquid inlet end is larger than that of the liquid outlet end. Firstly, it is to avoid that the centrifugal force in the center is small, the molten metal does not enter the product in time but solidifies in a narrow space, blocking the channel; secondly, a closed casting system is formed to reduce the secondary oxidation of the molten metal in the casting system and ensure product quality.

[0031] In step d, after the product is filled, the molten metal stops pouring, allowing the die cavity to remain hollow or with a small amount of metal remaining, thereby reducing the amount of metal used, increasing the product yield and saving costs.

[0032] The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to the above descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A dynamic solidification pouring system for investment casting, characterized in that: The pouring system includes a die head and several mold shell structures arranged around the die head, and the die head and the mold shell structures cooperate with each other; the die head includes a pouring column, the upper part of the pouring column is provided with an exhaust structure, and the lower part is provided with a spiral auxiliary runner; the mold shell structure includes a product pouring cavity, the top of the mold shell structure is provided with an upper connection port, and the bottom of the mold shell structure is provided with a lower pouring channel.

2. A dynamic solidification pouring system for investment casting according to claim 1, characterized in that: The exhaust structure comprises a circular exhaust chassis, and the exhaust chassis is connected to the casting column through a plurality of exhaust ribs, and the exhaust ribs are in an arc shape.

3. A dynamic solidification pouring system for investment casting according to claim 2, characterized in that: The upper part of the casting column is an inverted cone-shaped pouring cup. One end of the exhaust rib is connected to the outside of the pouring cup, and the other end is connected to the exhaust chassis through a raised guide portion. The guide portion cooperates with the upper connection port of the mold shell structure, and the exhaust rib and the mold shell structure are arranged one by one.

4. A dynamic solidification pouring system for investment casting according to claim 1, characterized in that: The spiral auxiliary pouring channel comprises a cylindrical outer shell, in which a plurality of rotating blades are evenly distributed, one end of the rotating blades is connected to the casting column, and the other end is connected to the inner wall of the cylindrical outer shell.

5. A dynamic solidification pouring system for investment casting according to claim 4, characterized in that: One end of the rotating blade connected to the casting column is the liquid inlet end, and the other end is the liquid outlet end. The ratio of the cross-section of the liquid inlet end to the cross-section of the liquid outlet end is 1.5-3:

1. The number of rotating blades corresponds to the number of mold shell structures. The mold shell structure is connected to the rotating blades through the lower casting channel.

6. A dynamic solidification pouring system for investment casting according to claim 1, characterized in that: The number of formwork structures is 3-7.

7. The method for using a dynamic solidification pouring system for investment casting according to claim 1, characterized in that: The steps of the method of use are as follows: a. assemble a plurality of mold shell structures around the die head, and the die head is installed on a centrifuge; b. start the centrifuge to rotate slowly, accelerate from 5-10 rpm to 10-30 rpm, and introduce the molten metal into the pouring system along the pouring cup; c. accelerate the centrifuge to 250-350 rpm, and after entering the pouring system, the molten metal enters the product pouring cavity of the mold shell structure along the spiral auxiliary pouring channel under the action of centrifugal force, and solidifies layer by layer against the mold shell, and each layer of metal solidifies sequentially, and the filling is completed quickly and smoothly; d. After the product filling is completed, the molten metal stops pouring, and the centrifuge continues to rotate until the molten metal is completely solidified, and then the centrifuge stops rotating to complete the pouring work.

8. The method for using a dynamic solidification pouring system for investment casting according to claim 7, characterized in that: In step c, an exhaust structure is provided on the upper part of the casting column, and the exhaust structure includes a circular exhaust chassis, and the exhaust chassis is connected to the casting column by a plurality of exhaust ribs, and the exhaust ribs are in the shape of an arc; when the molten metal is filled from bottom to top under the action of centrifugal force, the original air in the inner cavity of the product casting will be squeezed to the uppermost layer of the casting system and discharged from the casting system through the exhaust structure.

9. The method for using a dynamic solidification pouring system for investment casting according to claim 7, characterized in that: In step c, during pouring, the molten metal enters the product pouring cavity under the action of centrifugal force and solidifies in layers along the outer wall, solidifying from the outer layer to the inner layer.

10. The method for using a dynamic solidification pouring system for investment casting according to claim 7, characterized in that: In step c, the spiral auxiliary runner includes a cylindrical outer shell, and a plurality of rotating blades are evenly distributed inside the cylindrical outer shell. One end of the rotating blade is connected to the casting column, and the other end is connected to the inner wall of the cylindrical outer shell; the end of the rotating blade connected to the casting column is the liquid inlet end, and the other end is the liquid outlet end. The cross-section of the liquid inlet end is larger than that of the liquid outlet end, so that a closed casting system is formed after the molten metal enters, thereby reducing the secondary oxidation of the metal in the casting system.

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