Pouring system and pouring method for low-pressure casting

Abstract

The invention discloses a pouring system and a pouring method for low-pressure casting, the pouring system comprises pouring gates, cut-off devices and a control unit, when any horizontal pouring gate above the lowermost horizontal pouring gate is filled with molten metal, the cut-off device corresponding to the adjacent lower horizontal pouring gate is controlled by the control unit to be closed; and when the dead head is filled with molten metal, the control unit controls the last cut-off device to be closed, so that the pouring process is completed. According to the technical scheme, the cut-off devices are controlled by the control unit, so that the cut-off devices are sequentially closed from bottom to top, a casting cavity is regularly filled from bottom to top, the casting cavity is regularly solidified from bottom to top in the solidification process, a local overheated area is prevented from being formed in the casting solidification process, and the casting quality is improved. Therefore, the defects such as looseness, segregation and even hot cracking are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of casting, and in particular to a pouring system and a pouring method for low-pressure casting. Background Art

[0002] Large aluminum alloy castings have the advantages of high overall strength, low manufacturing cost, and low density, and are widely used in aerospace, weapons industry and other fields.

[0003] Due to the particularity of large aluminum alloy castings, low-pressure casting is generally used. Low-pressure casting is a method of filling the mold cavity with liquid metal under pressure to form a casting. However, during the casting process of large aluminum alloy castings, the gate area at the bottom of the casting cavity is subjected to long-term erosion by high-temperature molten metal, and the thermal conductivity of the sand mold is reduced, thereby forming a local overheating area during the solidification process of the casting, which is prone to defects such as looseness, segregation, and even thermal cracking. Summary of the invention

[0004] In view of this, the present invention provides a low-pressure casting pouring system, which realizes sequential pouring and filling of the casting cavity from bottom to top, thereby enabling the casting to solidify sequentially from bottom to top.

[0005] The present invention also provides a casting method comprising the casting system of the low-pressure casting.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A low-pressure casting pouring system, used for pouring aluminum alloy castings, comprising:

[0008] The runner includes a plurality of horizontal runners, a plurality of slit runners and at least one group of liquid inlet runners; the plurality of horizontal runners are evenly spaced from bottom to top, and adjacent horizontal runners are connected by a group of slit runners;

[0009] The first end of the slot runner at the top is connected to the horizontal runner at the top, and the second end is provided with a riser; the number of groups of the slot runners is equal to the number of the horizontal runners, and each slot runner is provided with a pouring part connected to the casting cavity;

[0010] The liquid inlet runner includes a vertical runner and a plurality of connecting runners, the number of the connecting runners corresponds to the number of the horizontal runners; one end of each connecting runner is connected to the liquid outlet end of the vertical runner, and the other end is respectively connected to the corresponding horizontal runner; the liquid inlet end of the vertical runner is used to connect to the pouring port;

[0011] Cut-off devices, the number of which corresponds to the number of the connecting runners, and each connecting runner is provided with a corresponding cut-off device;

[0012] A control unit, the control unit is used to control the closing of each of the shut-off devices;

[0013] Among them, when any of the horizontal runners above the lowest horizontal runner is filled with molten metal, the shut-off device corresponding to the adjacent horizontal runner below it is controlled to close by the control unit; when the riser is filled with molten metal, the control unit controls the last shut-off device to close to complete the pouring process.

[0014] Preferably, each group of the slit runners includes a plurality of sub-slit runners, the plurality of sub-slit runners are arranged around the circumference of the casting cavity, and each of the sub-slit runners is provided with the pouring part.

[0015] Preferably, the sub-slot runners in one group of the slot runners are staggered in vertical direction with respect to the projections of the sub-slot runners in an adjacent group of the slot runners.

[0016] Preferably, the number of the sub-slit runners is four, and the angle between adjacent sub-slit runners is 90 degrees.

[0017] Preferably, the height of the pouring portion is equal to the height of the sub-gap runner.

[0018] Preferably, the horizontal runner is in the shape of a circular ring.

[0019] Preferably, the shutoff device comprises a shutoff valve and a motor;

[0020] The shut-off valve is arranged on the connecting runner, and the rotation switch of the shut-off valve is connected to the motor. The motor receives and executes the instruction of the control unit to control the closing of the shut-off valve.

[0021] Preferably, the shut-off valve comprises: a shut-off valve cover, a hole core, a connecting rod and a driven wheel;

[0022] The shut-off valve cover is provided with a liquid inlet and a liquid outlet;

[0023] The hole core is located on the flow channel formed between the liquid inlet and the liquid outlet, and the hole core is connected to the driven wheel located outside the shut-off valve cover body through the connecting rod. The motor controls the rotation of the hole core through the driven wheel to control the flow channel to be disconnected.

[0024] Preferably, the control unit comprises: a controller and a plurality of groups of signal lines;

[0025] The signal line includes a first wire and a second wire, and the first end of the first wire and the first end of the second wire of the signal line are both connected to the controller; the second end of the first wire and the second end of the second wire constitute a liquid contact end, and the second end of the first wire and the second end of the second wire are arranged at a distance;

[0026] Wherein, the liquid receiving ends of each group of the signal wires are respectively preset in each of the horizontal runners located above the lowest horizontal runner; when the horizontal runners with the liquid receiving ends preset are filled with molten metal, a loop is formed between the first wire, the second wire and the controller, and the controller receives the signal that the horizontal runner is filled with molten metal, thereby controlling the shut-off device corresponding to the adjacent lower horizontal runner to be closed;

[0027] The liquid contact ends of the top group of signal wires are preset in the riser. When the riser is filled with molten metal, a loop is formed between the first wire, the second wire and the controller. The controller receives the signal that the riser is full of molten metal, thereby controlling the last shut-off device to close to complete the pouring process.

[0028] A pouring method, applied to the low-pressure casting pouring system, the pouring method comprising:

[0029] After coating a layer of mold release agent on the mold of the low-pressure casting pouring system, a sand mixer is used to mix sand and shape it to form a sand mold;

[0030] The intercepting device is installed at a preset position in the sand mold, and the liquid inlet end of the vertical runner is connected to the pouring port through the pouring channel;

[0031] The molten metal is poured into the pouring port so that the molten metal is poured into the casting cavity in sequence through the pouring port, the pouring channel, the liquid inlet runner, the gap runner, and the pouring part. The pouring process is completed when the last shut-off device is closed, and the casting is formed after the molten metal is cooled and solidified.

[0032] It can be seen from the above technical scheme that the pouring system for low-pressure casting provided by the present invention utilizes the control unit to control each shut-off device, so that each shut-off device is closed in sequence from bottom to top, so that the casting cavity is filled regularly from bottom to top (to avoid the gate area at the bottom of the casting cavity being eroded by the high-temperature molten metal for a long time), and then the solidification process of the casting cavity is solidified regularly from bottom to top, avoiding the formation of local overheating areas during the solidification process of the casting, thereby avoiding the occurrence of defects such as looseness, segregation and even thermal cracking.

[0033] The present invention also provides a pouring method, which has corresponding beneficial effects due to the application of a low-pressure casting pouring system. For details, please refer to the above description, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic diagram of the structure of a casting provided by an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of the structure of a pouring system provided by an embodiment of the present invention;

[0037] Figure 3 A schematic diagram of the structure of a pouring system (hiding the casting cavity) provided in an embodiment of the present invention;

[0038] Figure 4a A schematic diagram of the structure of a flow interception device provided in an embodiment of the present invention;

[0039] Figure 4b A cross-sectional view from a first perspective of a flow intercepting device provided by an embodiment of the present invention;

[0040] Figure 4c A cross-sectional view from a second perspective of the intercepting device provided by an embodiment of the present invention;

[0041] Figure 5 A control schematic diagram of a pouring system provided by an embodiment of the present invention;

[0042] Figure 6 A schematic flow chart of a casting method provided in an embodiment of the present invention.

[0043] The meanings of the reference numerals in the figures are as follows:

[0044] 10 is a runner, 11 is a horizontal runner, 12 is a gap runner, 121 is a sub-gap runner, 13 is a liquid inlet runner, 131 is a vertical runner, 132 is a connecting runner, 14 is a pouring part, and 15 is a riser;

[0045] 20 is a shutoff device, 21 is a shutoff valve, 211 is a shutoff valve cover, 212 is a hole core, 213 is a connecting rod, 214 is a driven wheel, 215 is a positioning rod, and 22 is a motor;

[0046] 30 is a control unit, 31 is a controller, 32 is a signal line; 40 is a casting cavity; 50 is a casting. DETAILED DESCRIPTION

[0047] 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.

[0048] The pouring system for low pressure casting provided by the embodiment of the present invention is applied to the pouring of aluminum alloy castings, such as Figure 1-Figure 6 As shown,

[0049] The runner 10 includes a plurality of horizontal runners 11, a plurality of slit runners 12 and at least one group of liquid inlet runners 13; the plurality of horizontal runners 11 are evenly spaced from bottom to top, and adjacent horizontal runners 11 are connected by a group of slit runners 12;

[0050] The first end of the slot runner 12 at the top is connected to the horizontal runner 11 at the top, and the second end is provided with a riser 15; the number of groups of slot runners 12 is equal to the number of horizontal runners 11, and each slot runner 12 is provided with a pouring part 14 connected to the casting cavity 40;

[0051] The liquid inlet runner 13 includes a vertical runner 131 and a plurality of connecting runners 132, the number of connecting runners 132 corresponds to the number of horizontal runners 11; one end of each connecting runner 132 is connected to the liquid outlet end of the vertical runner 131, and the other end is connected to the corresponding horizontal runner 11; the liquid inlet end of the vertical runner 131 is used to connect to the pouring port;

[0052] The intercepting device 20 has a number corresponding to the number of the connecting runners 132, and each connecting runner 132 is provided with a corresponding intercepting device 20;

[0053] A control unit 30, the control unit 30 is used to control the closing of each intercepting device 20, so that each intercepting device 20 is closed from bottom to bottom during the pouring process, so that after each horizontal runner 11 is filled with molten metal, no more molten metal flows in from bottom to top;

[0054] Among them, when any horizontal runner 11 located above the lowest horizontal runner 11 is filled with molten metal, the shut-off device 20 corresponding to the adjacent horizontal runner 11 below is controlled to close by the control unit 30; when the riser 15 is filled with molten metal, the control unit 30 controls the last shut-off device 20 to close to complete the pouring process.

[0055] In the above scheme, the basic principle of the pouring process is that when pouring starts, all the shut-off devices 20 are opened, and when the molten metal flows from the pouring port through the vertical runner 131, the connecting runner 132, the horizontal runner 11 and the gap runner 12 in sequence, and finally fills the casting cavity 40 from the pouring part 14, the flow direction of the molten metal is as follows: Figure 2 As shown by the arrow; during the above-mentioned pouring process, the control unit 30 controls the shut-off device 20 arranged on the connecting runner 132 (to close it), so that the shut-off device 20 is closed from bottom to top in sequence, so that the casting cavity 40 is regularly filled from bottom to top (to prevent the gate area at the bottom of the casting cavity from being flushed by the high-temperature molten metal for a long time), and then the solidification process of the casting cavity 40 is regularly solidified from bottom to top, avoiding the formation of local overheating areas during the solidification process of the casting, thereby avoiding the occurrence of defects such as looseness, segregation and even thermal cracking.

[0056] In an optional embodiment, if Figure 2 and Figure 3 As shown, each group of slit runners 12 includes a plurality of sub-slit runners 121, and the plurality of sub-slit runners 121 are arranged circumferentially around the casting cavity 40, and each sub-slit runner 121 is provided with a pouring portion 14. In the present technical solution, by providing a plurality of sub-slit runners 121, the casting cavity 40 can be filled at multiple angles, so that it is heated and solidified uniformly, and further porosity, segregation and even thermal cracking defects after solidification can be avoided.

[0057] Optimize the above technical solutions, such as Figure 2 and Figure 3 As shown, the sub-slit runner 121 in one group of slot runners 12 is staggered with the projection of the sub-slit runner 121 in the adjacent group of slot runners 12 in the vertical direction. This arrangement avoids the sub-slit runners 121 in each group from being connected in a straight line in the vertical direction, which causes the metal liquid to flow faster and thus destroy the sand mold. It also allows the liquid to flow evenly into each part of the casting cavity 40, and can also compensate for the shrinkage of the casting solidification process below, so as to obtain better metallurgical quality.

[0058] The above technical solution is optimized, the number of sub-slit runners 121 is four, and the angle between adjacent sub-slit runners 121 is 90 degrees, so that the casting cavity 40 is evenly filled with liquid from four directions, which is beneficial to the filling of the casting cavity 40 and the solidification of the casting 50.

[0059] Optimize the above technical solutions, such as Figure 2 As shown, the height of the pouring portion 14 is equal to the height of the sub-gap runner 121, which can allow the casting cavity 40 to be quickly filled and avoid excessive flow of molten metal, which would damage the sand mold.

[0060] In an optional embodiment, the horizontal runner 11 is in the shape of a circular ring, which is conducive to the filling of the casting cavity 40. However, in actual industrial applications, the specific shape of the horizontal runner 11 can be adjusted according to the shape of the casting cavity 40, and there is no limitation on this.

[0061] In an optional embodiment, if Figure 4a-4b As shown, the shutoff device 20 includes a shutoff valve 21 and a motor 22;

[0062] The shut-off valve 21 is arranged on the connecting runner 132, and the rotary switch of the shut-off valve 21 is connected to the motor 22. The motor 22 receives and executes the instructions of the control unit 30 to control the closing of the shut-off valve 21. In the present technical solution, the shut-off device 20 is closed in sequence by controlling the shut-off valve 21; in addition, the control unit 30 can also issue instructions to control the opening of the shut-off valve 21 as needed.

[0063] Optimize the above technical solutions, such as Figure 4a As shown, the shut-off valve 21 includes: a shut-off valve cover 211, a hole core 212, a connecting rod 213 and a driven wheel 214:

[0064] The shut-off valve cover 211 has a liquid inlet and a liquid outlet;

[0065] The hole core 212 is located on the flow channel formed between the liquid inlet and the liquid outlet.

[0066] The hole core 212 is located on the flow channel formed between the liquid inlet and the liquid outlet, and the hole core 212 is connected to the driven wheel 214 located outside the shut-off valve cover 211 through the connecting rod 213. The motor 22 controls the rotation of the hole core 212 through the driven wheel 214 to control the flow and disconnection of the flow channel. In this technical solution, when the motor 22 receives and executes the instructions of the control unit 30, the motor 22 controls the disconnection of the flow channel through the driven wheel 214 to achieve the closure of the shut-off valve 21.

[0067] Optimize the above technical solutions, such as Figure 4a-4c As shown, the hole core 212 is composed of a round iron ball or steel ball with a central through hole, and a positioning rod 215 is installed below the hole core 212 for positioning in the sand mold; the shut-off valve cover 211 is composed of a left cover and a right cover, and the left cover and the right cover are respectively installed on the semicircular structure on both sides of the hole core 212, with a through hole reserved on the top for the connecting rod 213 to pass through, and a through hole reserved on the bottom for the positioning rod 215 to insert; the left cover and the right cover are respectively reserved with a cover through hole with the same inner diameter as the central through hole of the hole core 212 (that is, the liquid inlet and the liquid outlet are the cover through holes) to facilitate the passage of molten metal.

[0068] In an optional embodiment, the control unit 30 includes: a controller 31 and a plurality of groups of signal lines 32;

[0069] The signal line 32 includes a first wire and a second wire, and the first end of the first wire and the first end of the second wire of the signal line 32 are both connected to the controller 31; the second end of the first wire and the second end of the second wire constitute a liquid contact end, and the second end of the first wire and the second end of the second wire are arranged at a distance, so that when the horizontal runner 11 or the riser 15 is preset and the horizontal runner 11 or the riser 15 is not filled with molten metal, the second end of the first wire and the second end of the second wire are disconnected and not connected;

[0070] The liquid receiving ends of each group of signal lines 32 are respectively preset in each horizontal runner 11 located above the lowest horizontal runner 11; when the horizontal runner 11 with the liquid receiving end preset is filled with molten metal, a loop is formed between the first wire, the second wire and the controller 31, and the controller 31 receives the signal that the horizontal runner 11 is full of molten metal, thereby controlling the shutoff device 20 corresponding to the adjacent lower horizontal runner 11 to be closed;

[0071] The liquid contact ends of the top group of signal wires 32 are preset in the riser 15. When the riser 15 is filled with molten metal, a loop is formed between the first wire, the second wire and the controller 31. The controller receives the signal that the riser 15 is full of molten metal, thereby controlling the last shut-off device 20 to close to complete the pouring process.

[0072] In the above technical solution, the second end of the first wire and the second end of the second wire cooperate with the molten metal, so that the controller 31 can receive the information that the corresponding horizontal runner 11 is filled with molten metal, and then use the interception device 20 to complete the filling of the casting cavity 40 from bottom to top, so as to avoid the gate area at the bottom of the casting cavity 40 being subjected to a long flushing time of the high-temperature alloy liquid (i.e., molten metal) from the beginning to the end of pouring; it should be noted that the gate area can be understood as the area connected between the pouring part 14 and the casting cavity 40.

[0073] In the optimization of the above technical solution, the control unit 30 also includes an execution module, which is used to control the pouring of molten metal. When the controller receives a signal that the riser 15 is full of molten metal, in addition to controlling the last shut-off device 20 to close, it also controls the execution module to stop the pouring of molten metal.

[0074] On the basis of any of the above embodiments, the number of the liquid inlet runners 13 is multiple groups, and preferably the number of the liquid inlet runners 13 is two groups, and the two groups of liquid inlet runners 13 are symmetrically arranged.

[0075] A pouring method is applied to the above-mentioned low-pressure casting pouring system, the low-pressure casting pouring system comprising:

[0076] S1. After coating a layer of release agent on the mold of the low-pressure casting pouring system, a sand mixer is used to mix sand and form a sand mold;

[0077] Among them, after the mold is coated with a layer of release agent, it is dried and then assembled. It should also be noted that the sand mold can be formed in sections using the mold according to actual needs. After the sectioned molding, the sand molds are assembled in sequence from bottom to top on the mobile platform;

[0078] S2, installing the intercepting device 20 at a preset position in the sand mold, and connecting the liquid inlet end of the vertical runner 131 to the pouring port through the pouring channel;

[0079] S3, pouring molten metal into the casting cavity 40 through the pouring gate, the pouring channel, the liquid inlet runner 13, the gap runner 12, and the pouring part 14 in sequence, and the pouring process is completed when the last shut-off device 20 is closed, and the casting 50 is formed after the molten metal is cooled and solidified.

[0080] By using the above-mentioned pouring method, it is possible to achieve stable filling of large aluminum alloy hanging castings from bottom to top and sequential solidification from bottom to top, thus solving the problem of defects such as looseness, segregation and cracks that are prone to occur at the bottom of large castings.

[0081] In a specific embodiment, Figure 1 As shown, the casting 50 cast by the low-pressure casting pouring system or pouring method is placed on the outside of the aircraft. The outline dimensions of the casting 50 are 2500mm in height, 500~1100mm in diameter, and 3~5mm in overall wall thickness; after being cast by the low-pressure casting pouring system or pouring method, the casting 50 is subjected to X-ray inspection, and the metallurgical quality inside the casting 50 meets the requirements of HB963-2005 Class I parts. The cutting performance of the designated area 3 on the casting 50 reaches a tensile strength σb=480MPa and an elongation δ=13%; it should also be noted that the casting 50 has a large diameter and a small diameter.

[0082] In another specific embodiment, Figure 1-Figure 5As shown, the number of horizontal runners 11 is four, which are respectively the first horizontal runner, the second horizontal runner, the third horizontal runner and the fourth horizontal runner from bottom to top; the number of intercepting devices 20 is four, which are respectively the first intercepting device, the second intercepting device, the third intercepting device and the fourth intercepting device from bottom to top; the number of connecting runners 132 is four, which are respectively the first connecting runner, the second connecting runner, the third connecting runner and the fourth connecting runner from bottom to top; when the second horizontal runner is filled with molten metal, the control unit 30 receives the information that the second horizontal runner is filled with molten metal, and then controls the first intercepting device (arranged on the first connecting runner) corresponding to the first horizontal runner Closed; when the third horizontal runner is full of molten metal, the control unit 30 receives the information that the third horizontal runner is full of molten metal, and then controls the second shut-off device (disposed on the second connecting runner) corresponding to the second horizontal runner to close; when the fourth horizontal runner is full of molten metal, the control unit 30 receives the information that the fourth horizontal runner is full of molten metal, and then controls the third shut-off device (disposed on the third connecting runner) corresponding to the third horizontal runner to close; when the riser 15 is full of molten metal, the control unit 30 receives the information that the riser 15 is full of molten metal, and then controls the fourth shut-off device (disposed on the fourth connecting runner) corresponding to the fourth horizontal runner to close.

[0083] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0084] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A low pressure casting pouring system, used for pouring aluminum alloy castings, characterized in that: include: The runner (10) comprises a plurality of horizontal runners (11), a plurality of groups of slit runners (12) and at least one group of liquid inlet runners (13); the plurality of horizontal runners (11) are evenly spaced from bottom to top, and adjacent horizontal runners (11) are connected via a group of slit runners (12); The first end of the slit runner (12) located at the top is connected to the horizontal runner (11) located at the top, and the second end is provided with a riser (15); the number of groups of the slit runners (12) is equal to the number of the horizontal runners (11), and each of the slit runners (12) is provided with a pouring portion (14) connected to the casting cavity (40); The liquid inlet runner (13) comprises a vertical runner (131) and a plurality of connecting runners (132), the number of the connecting runners (132) corresponding to the number of the horizontal runners (11); one end of each connecting runner (132) is connected to the liquid outlet end of the vertical runner (131), and the other end is respectively connected to the corresponding horizontal runner (11); the liquid inlet end of the vertical runner (131) is used to be connected to the pouring port; Cut-off devices (20), the number of the cut-off devices (20) corresponding to the number of the connecting runners (132), and each connecting runner (132) is provided with a corresponding cut-off device (20); A control unit (30), the control unit (30) being used to control the closing of each of the shut-off devices (20); When any of the horizontal runners (11) above the lowest horizontal runner (11) is filled with molten metal, the shut-off device (20) corresponding to the adjacent horizontal runner (11) below it is controlled to close by the control unit (30); when the riser (15) is filled with molten metal, the control unit (30) controls the last shut-off device (20) to close, so as to complete the pouring process.

2. The pouring system according to claim 1, characterized in that: Each group of the slit runners (12) comprises a plurality of sub-slit runners (121), the plurality of sub-slit runners (121) are arranged around the circumference of the casting cavity (40), and each of the sub-slit runners (121) is provided with the pouring portion (14).

3. The pouring system according to claim 2, characterized in that: The projections of the sub-slit runners (121) in one group of the slot runners (12) and the sub-slit runners (121) in an adjacent group of the slot runners (12) in the vertical direction are staggered.

4. The pouring system according to claim 2, characterized in that: The number of the sub-slit runners (121) is four, and the included angle between adjacent sub-slit runners (121) is 90 degrees.

5. The pouring system according to claim 2, characterized in that: The height of the pouring portion (14) is equal to the height of the sub-gap runner (121).

6. The pouring system according to claim 1, characterized in that: The horizontal runner (11) is in the shape of a circular ring.

7. The pouring system according to claim 1, characterized in that: The shutoff device (20) comprises a shutoff valve (21) and a motor (22); The shut-off valve (21) is arranged on the connecting runner (132), and a rotary switch of the shut-off valve (21) is connected to the motor (22), and the motor (22) receives and executes instructions from the control unit (30) to control the closing of the shut-off valve (21).

8. The pouring system according to claim 7, characterized in that: The shut-off valve (21) comprises: a shut-off valve cover (211), a hole core (212), a connecting rod (213) and a driven wheel (214); The shut-off valve cover (211) has a liquid inlet and a liquid outlet; The hole core (212) is located on the flow channel formed between the liquid inlet and the liquid outlet, and the hole core (212) is connected to the driven wheel (214) located outside the shut-off valve cover (211) via the connecting rod (213), and the motor (22) controls the rotation of the hole core (212) via the driven wheel (214) to control the disconnection of the flow channel.

9. The pouring system according to any one of claims 1 to 8, characterized in that: The control unit (30) comprises: a controller (31) and a plurality of groups of signal lines (32); The signal line (32) comprises a first wire and a second wire, and the first end of the first wire and the first end of the second wire of the signal line (32) are both connected to the controller (31); the second end of the first wire and the second end of the second wire constitute a liquid contact end, and the second end of the first wire and the second end of the second wire are arranged at a distance; Wherein, the liquid receiving ends of each group of the signal wires (32) are respectively preset in each of the horizontal runners (11) located above the lowest horizontal runner (11); when the horizontal runner (11) with the liquid receiving ends preset is filled with molten metal, a loop is formed between the first wire, the second wire and the controller (31), and the controller (31) receives a signal indicating that the horizontal runner (11) is filled with molten metal, thereby controlling the shutoff device (20) corresponding to the adjacent lower horizontal runner (11) to be closed; The liquid contacting end of the uppermost group of signal wires (32) is preset in the riser (15); when the riser (15) is filled with molten metal, a loop is formed between the first wire, the second wire and the controller (31); the controller receives a signal indicating that the riser (15) is filled with molten metal, thereby controlling the last shut-off device (20) to close, thereby completing the pouring process.

10. A casting method, characterized in that: The low pressure casting pouring system applied to any one of claims 1 to 9, wherein the pouring method comprises: After coating a layer of mold release agent on the mold of the low-pressure casting pouring system, a sand mixer is used to mix sand and shape it to form a sand mold; The intercepting device (20) is installed at a preset position in the sand mold, and the liquid inlet end of the vertical runner (131) is connected to the pouring port through a pouring channel; The molten metal is poured into the casting cavity (40) based on the pouring port, so that the molten metal is poured into the casting cavity (40) in sequence through the pouring port, the pouring channel, the liquid inlet runner (13), the slit runner (12), and the pouring portion (14). The pouring process is completed when the last shut-off device (20) is closed, and the casting (50) is formed after the molten metal is cooled and solidified.

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