Die-casting mold runner feeding structure of thin-wall die casting

Abstract

The invention relates to the technical field of die-casting equipment, and discloses a die-casting die runner feeding structure for thin-wall die castings, which comprises a cavity, an overflow cavity, an extension cavity and a die-casting runner system, and the die-casting runner system, the extension cavity, the cavity and the overflow cavity are sequentially arranged along a first preset direction; the extension cavity comprises a first cavity and a second cavity which are communicated with each other, a feed port of the die-casting runner system is connected with the first cavity, the cavity is provided with a main body cavity, and the main body cavity is connected with the second cavity; in a second preset direction perpendicular to the first preset direction, the distance between the two side walls of the feeding opening is larger than that between the two side walls of the main body cavity; the projection, in the first preset direction, of the feeding opening is located in the first cavity; the projection of the second cavity in the first preset direction is located in the main body cavity. According to the flow channel feeding structure of the die-casting die for the thin-wall die-casting piece, erosion of metal liquid to the die can be reduced, the service life of the die is prolonged, and the manufacturing cost of the thin-wall die-casting piece is reduced.

Description

Technical Field

[0001] This invention relates to the field of die casting equipment technology, and in particular to a die casting mold flow channel feeding structure for thin-walled die castings. Background Technology

[0002] The runner design of a die-casting mold is crucial to the quality of the casting. During die-casting, molten metal directly impacts the mold cavity under high speed and pressure. Erosion often occurs at the mold cavity's inlet, leading to defects such as excess material, pitting, cracking, and deformation. Furthermore, severe erosion of the mold cavity is difficult to repair, quickly rendering the entire mold unusable and causing unnecessary losses. This is especially true for thin-walled castings, with wall thicknesses less than 1mm, or even as thin as 0.3-0.5mm at the thinnest points. The molten metal entering the mold cavity is squeezed at even higher speeds, making the product surface more prone to marks and the mold more susceptible to cracking. Current solutions include increasing the draft angle and radius at erosion-prone areas of the mold cavity, or replacing these areas with spare inserts. However, erosion-prone areas are typically internal corners. Increasing the draft angle and radius requires high-precision machining, which is difficult and costly. Replacing the mold with spare inserts increases mold costs and necessitates production stoppages, impacting production schedules.

[0003] Therefore, it is necessary to provide a die casting mold runner feeding structure that can reduce erosion of the mold, extend the mold service life, and reduce the manufacturing cost of thin-walled castings. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a die casting mold flow channel feeding structure for thin-walled die castings, which can reduce the erosion of the mold by molten metal, extend the service life of the mold, and reduce the manufacturing cost of thin-walled castings.

[0005] To solve the above-mentioned technical problems, the present invention provides a die casting mold flow channel feeding structure for thin-walled die casting parts, including a cavity, an overflow cavity, an extension cavity and a die casting flow channel system, wherein the die casting flow channel system, the extension cavity, the cavity and the overflow cavity are arranged sequentially along a first preset direction;

[0006] The extended cavity includes a first chamber and a second chamber that are interconnected. The die-casting flow channel system has multiple branch flow channels arranged side by side. Each branch flow channel has a feed inlet, which is connected to the first chamber. The mold cavity has a main chamber, which is connected to the second chamber.

[0007] In a second preset direction perpendicular to the first preset direction, the distance between the two side walls of the feed inlet is greater than the distance between the two side walls of the main chamber;

[0008] The projection of the feed inlet along the first preset direction is located inside the first cavity;

[0009] The projection of the second chamber along the first preset direction is located within the main body chamber.

[0010] As an improvement to the above solution, the first sidewall of the second chamber is arranged parallel to the first sidewall of the main chamber, and the second sidewall of the second chamber is arranged parallel to the second sidewall of the main chamber. The first sidewall and the second sidewall of the second chamber are arranged sequentially and opposite to each other in the second preset direction, and the first sidewall and the second sidewall of the main chamber are arranged sequentially and opposite to each other in the second preset direction.

[0011] The cavity further includes a first wing cavity that intersects and communicates with the main cavity. The first wing cavity is located at one end of the main cavity near the extension cavity. The first wing cavity extends from the main cavity in a second predetermined direction. The vertical distance between the first side wall of the second cavity and the first side wall of the main cavity is greater than the vertical distance between the second side wall of the second cavity and the second side wall of the main cavity.

[0012] As an improvement to the above solution, the extension cavity is continuously arranged in a third preset direction, which is perpendicular to the first preset direction and the second preset direction.

[0013] As an improvement to the above solution, the first chamber includes an expansion section and a narrowing section. The expansion section is connected to the feed inlet, and the vertical distance between the first sidewall and the second sidewall of the expansion section gradually increases in the direction away from the feed inlet. The narrowing section is connected to the second chamber, and the vertical distance between the first sidewall and the second sidewall of the narrowing section gradually increases in the direction away from the second chamber. The first sidewall and the second sidewall of the expansion section are arranged sequentially and opposite to each other in the second preset direction. The first sidewall and the second sidewall of the narrowing section are arranged sequentially and opposite to each other in the second preset direction.

[0014] The first and second sidewalls of the narrowing section each include an inclined surface, a first curved surface, and a second curved surface arranged sequentially along the first preset direction. The second curved surface is connected to the second chamber. The first curved surface is a convex arc surface, and the second curved surface is a concave arc surface. The projection of the feed port along the first preset direction is located on the first curved surface.

[0015] As an improvement to the above solution, the slope of the inclined plane is no greater than 45°;

[0016] The length ratio of the expansion segment to the narrowing segment along the first preset direction is 1 / 8 to 1 / 4;

[0017] The length ratio of the expansion section to the second chamber along the first preset direction is 1 / 4 to 1 / 2;

[0018] The ratio of the vertical distance between the first and second sidewalls of the feed inlet to the maximum vertical distance between the first and second sidewalls of the expansion section is 1 / 3 to 2 / 3.

[0019] As an improvement to the above scheme, the vertical distance between the second sidewall of the second chamber and the second sidewall of the main chamber does not exceed 1 / 2 of the vertical distance between the first sidewall and the second sidewall of the second chamber.

[0020] As an improvement to the above solution, the feed inlet is mirror-symmetrical about the first plane, and the extension cavity is mirror-symmetrical about the first plane.

[0021] As an improvement to the above solution, the cavity further includes a second side wing cavity that intersects and communicates with the main cavity. The second side wing cavity is located at the end of the main cavity away from the extension cavity. The second side wing cavity extends from the main cavity in a second preset direction. The second cavity communicates with the first side wing cavity, and the overflow cavity communicates with the second side wing cavity.

[0022] As an improvement to the above solution, the die-casting runner system further includes a main runner and a forward runner assembly. The main runner is connected to the main runner. The forward runner assembly is mirror-symmetrical about the axis of the main runner and includes the main runner and the branch runners. The branch runners are located on the side of the main runner away from the main runner. Each branch runner is arranged along the flow direction of the main runner, and each branch runner is intersected and connected to the main runner.

[0023] The cross-sectional area of ​​the main flow channel gradually decreases along its flow direction. The vertical distance between the first and second sidewalls of each branch flow channel, which are arranged sequentially and oppositely in the second preset direction, is equal. On the same cross-section, the farther the branch flow channel is from the main flow channel, the smaller the cross-sectional area of ​​the branch flow channel.

[0024] As an improvement to the above scheme, the first sidewall of each of the branch channels coincides with the first plane.

[0025] Implementing this invention has the following beneficial effects:

[0026] This invention discloses a die-casting mold flow channel feeding structure for thin-walled die-casting parts. The structure comprises a die-casting flow channel system, an extension cavity, a mold cavity, and an overflow cavity arranged sequentially along a first preset direction. An extension cavity is positioned between the feed inlet and the mold cavity. The first chamber of the extension cavity is connected to the feed inlet, and the projection of the feed inlet along the first preset direction is located within the first chamber. The projection of the second chamber of the extension cavity along the first preset direction is located within the main body cavity. In a second preset direction perpendicular to the first preset direction, the distance between the two side walls of the feed inlet is greater than the distance between the two side walls of the main body cavity. This allows for flow rate adjustment of the molten metal flowing into the extension cavity and position adjustment upon entering the main body cavity.

[0027] The projection of the feed inlet along the first preset direction is located in the first chamber, and the molten metal entering the first chamber through the feed inlet will be briefly buffered.

[0028] The projection of the second chamber of the extension cavity along the first preset direction is located in the main chamber. When the molten metal enters the second chamber from the first chamber, it will be accelerated, and the molten metal entering the main chamber from the second chamber will not directly impact the cavity wall of the main chamber, thus avoiding erosion of the main chamber and helping to extend the service life of the mold.

[0029] Meanwhile, the overflow cavity and the extension cavity are located at opposite ends of the cavity, allowing the molten metal to flow through the main cavity to the overflow cavity at a high speed, ensuring the filling speed of the main cavity and facilitating product demolding within the cavity. This is suitable for the production of products with thinner main cavities.

[0030] Since the distance between the two side walls of the feed inlet is greater than the distance between the two side walls of the main cavity in the second preset direction perpendicular to the first preset direction, this embodiment does not require special modification of the die casting flow channel system to adapt to the production of thin-walled products, and does not require structural modification of the easily eroded inner corner position in the cavity, thus avoiding the need for high-precision machining and downtime to replace spare inserts.

[0031] Since the die casting runner system, extension cavity, mold cavity, and overflow cavity are arranged sequentially along the first preset direction, and the projection of the second chamber along the first preset direction is located in the main body cavity, the extension cavity avoids the possible inner corner position of the mold cavity, and the corresponding casting structure of the extension cavity can be easily cut off. Compared with the existing technology, which increases the slope and enlarges the rounded corner in the mold cavity where it is easy to be eroded, or makes spare inserts for replacement in the product where it is easy to be eroded, the manufacturing cost is lower. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of an embodiment of the die casting mold flow channel feeding structure for a thin-walled die casting part according to the present invention;

[0033] Figure 2 yes Figure 1 A magnified structural diagram of part A;

[0034] Figure 3 yes Figure 1 A schematic diagram of the structure on the right side;

[0035] Figure 4 yes Figure 3 A magnified structural diagram of part B. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] like Figures 1 to 4 As shown, this invention discloses an embodiment of a die-casting mold runner feeding structure for thin-walled die-casting parts, including a cavity 1, an overflow cavity 2, an extension cavity 3, and a die-casting runner system. The die-casting runner system, the extension cavity 3, the cavity 1, and the overflow cavity 2 are arranged sequentially along a first preset direction. The extension cavity 3 includes a first chamber 31 and a second chamber 32 that are interconnected. The die-casting runner system has multiple branch runners 422 arranged side by side. Each branch runner 422 has a feed inlet 423, which is connected to the first chamber 31. The cavity 1 has a main chamber 11, which is connected to the second chamber 32. In a second preset direction perpendicular to the first preset direction, the distance between the two side walls of the feed inlet 423 is greater than the distance between the two side walls of the main chamber 11. The projection of the feed inlet 423 along the first preset direction is located within the first chamber 31. The projection of the second chamber 32 along the first preset direction is located within the main chamber 11.

[0038] In this embodiment, a die-casting runner system, an extension cavity 3, a mold cavity 1, and an overflow cavity 2 are sequentially arranged along a first preset direction. An extension cavity 3 is provided between the inlet 423 and the mold cavity 1. The first chamber 31 of the extension cavity 3 is connected to the inlet 423, and the projection of the inlet 423 along the first preset direction is located within the first chamber 31. The projection of the second chamber 32 of the extension cavity 3 along the first preset direction is located within the main chamber 11. In a second preset direction perpendicular to the first preset direction, the distance between the two side walls of the inlet 423 of the die-casting runner system is greater than the distance between the two side walls of the main chamber 11 in the mold cavity 1. This design allows for flow rate adjustment of the molten metal entering the extension chamber 3 via the inlet 423, as well as position adjustment upon entering the main chamber 11. The projection of the inlet 423 along a first preset direction is located within the first chamber 31, providing a brief buffer for the molten metal entering the first chamber 31. Conversely, the projection of the second chamber 32 of the extension chamber 3 along the first preset direction is located within the main chamber 11, accelerating the molten metal as it enters from the first chamber 31. This design also prevents the molten metal entering the main chamber 11 from directly impacting the chamber wall, thus avoiding damage to the main chamber 11. This causes erosion, helping to extend the mold's service life; simultaneously, the overflow cavity 2 and the extension cavity 3 are located at opposite ends of the cavity 1, allowing the molten metal to flow through the main cavity 11 at a high speed towards the overflow cavity 2, ensuring the filling speed of the main cavity 11 and facilitating product demolding within the cavity 1, suitable for producing products with thinner sections in the main cavity 11; in a second preset direction perpendicular to the first preset direction, the distance between the two side walls of the inlet is greater than the distance between the two side walls of the main cavity, thus this embodiment does not require special modifications to the die-casting runner system to adapt to the production of thin-walled products, and does not require... The structure of the easily eroded inner corner of cavity 1 needs to be modified to avoid the need for high-precision machining and downtime to replace spare inserts. Since the die casting flow channel system, extension cavity 3, cavity 1 and overflow cavity 2 are arranged in sequence along the first preset direction, and the projection of the second chamber 32 along the first preset direction is located in the main chamber 11, the extension cavity 3 avoids the possible inner corner of cavity 1. It is convenient to cut off the casting structure corresponding to the extension cavity 3. Compared with the existing technology, which increases the slope and enlarges the rounded corner in the easily eroded part of the mold cavity 1, or makes spare inserts for replacement in the easily eroded part of the product, the manufacturing cost is lower.

[0039] In this embodiment, the extension cavity 3 is continuously arranged in a third preset direction, which is perpendicular to the first preset direction and the second preset direction. When the molten metal from each branch channel 422 enters the extension cavity 3 through the inlet, the molten metal is buffered and collected in the first chamber 31. As it flows into the second chamber 32, the pouring angle increases as the chamber thickness decreases, causing the molten metal entering the main chamber 11 to diffuse earlier. The molten metal flows more evenly in the first preset direction within the main chamber 11, reducing the kinetic energy loss caused by collisions of the molten metal within the main chamber 11, thereby accelerating the filling of the molten metal and improving the molding effect.

[0040] It should be noted that the distance between the two side walls of the main cavity 11 in the second preset direction in this embodiment is the wall thickness of the main cavity 11.

[0041] The first preset direction in this embodiment refers specifically to the direction of vertical upward, that is, the molten metal flows from bottom to top as it passes through the die-casting flow channel system, extension cavity 3, mold cavity 1 and overflow cavity 2 arranged sequentially along the first preset direction.

[0042] In this embodiment, the first sidewall of the second chamber 32 is arranged parallel to the first sidewall of the main chamber 11, and the second sidewall of the second chamber 32 is arranged parallel to the second sidewall of the main chamber 11. The first sidewall of the second chamber 32 and the second sidewall of the second chamber 32 are arranged sequentially and opposite to each other in the second preset direction, and the first sidewall of the main chamber 11 and the second sidewall of the main chamber 11 are arranged sequentially and opposite to each other in the second preset direction.

[0043] In addition to the main cavity 11, the cavity 1 also includes a first side wing cavity 12 that intersects and communicates with the main cavity 11. The first side wing cavity 12 is located at one end of the main cavity 11 near the extension cavity 3, and extends from the main cavity 11 in a second predetermined direction. The vertical distance between the first side wall of the second cavity 32 and the first side wall of the main cavity 11 is greater than the vertical distance between the second side wall of the second cavity 32 and the second side wall of the main cavity 11. In this embodiment, the first side wing cavity 12 is located at the bottom of the main cavity 11, and the molten metal entering the main cavity 11 will fill the first side wing cavity 12 under the action of gravity.

[0044] Furthermore, the cavity 1 in this embodiment also includes a second side wing cavity 13 that intersects and communicates with the main cavity 11. The second side wing cavity 13 communicates with the first side wing cavity 12. The second side wing cavity 13 is located at the end of the main cavity 11 away from the extension cavity 3. The second side wing cavity 13 extends from the main cavity 11 in a second predetermined direction, and the overflow cavity 2 communicates with the second side wing cavity 13. On the one hand, the overflow cavity 2 can discharge air bubbles and other debris from the molten metal in the cavity 1, especially in the main cavity 11. On the other hand, it can provide insulation for the upper part of the main cavity 11 and the vicinity of the second side wing cavity 13, avoiding large temperature differences in different areas of the cavity 1 and helping to improve the die-casting quality. In addition, after the molten metal in the overflow cavity 2 and the extension cavity 3 solidifies, it can help demold thin-walled products in the cavity 1, avoiding defects such as deformation caused by demolding under ejector pin pressure.

[0045] In this embodiment, the vertical distance between the first sidewall of the second chamber 32 and the first sidewall of the main chamber 11 is set to be greater than the vertical distance between the second sidewall of the second chamber 32 and the second sidewall of the main chamber 11, and the vertical distance between the second sidewall of the second chamber 32 and the second sidewall of the main chamber 11 does not exceed 1 / 2 of the vertical distance between the first and second sidewalls of the second chamber 32. This allows the end fillets of the second chamber 32 and the main chamber 11 to be staggered in the third preset direction, making it easier to cut the product and the corresponding structure of the extension cavity 3 after molding.

[0046] The die-casting runner system of this embodiment further includes a main runner 41 and a forward runner assembly 42. The main runner 421 connects to the main runner 41, and the forward runner assembly 42 is mirror-symmetrical about the axis of the main runner 41. The forward runner assembly 42 includes the main runner 421 and the branch runners 422. The branch runners 422 are located on the side of the main runner 421 away from the main runner 41. Each branch runner 422 is arranged along the flow direction of the main runner 421, and each branch runner 422 intersects and communicates with the main runner 421. The cross-sectional area of ​​the main flow channel 421 gradually decreases along its flow direction. The vertical distance between the first and second sidewalls of each branch flow channel 422 arranged sequentially and oppositely in the second preset direction is equal. On the same cross-section, the farther the branch flow channel 422 is from the main flow channel 41, the smaller the cross-sectional area of ​​the branch flow channel 422, so that the flow velocity of the liquid metal in the branch flow channel 422 that is farther from the main flow channel 41 is greater, thereby balancing the filling time difference caused by different paths. In the third preset direction, the filling progress of each part of the main chamber 11 is closer.

[0047] In this embodiment, the inlet 423 is floated upwards towards the branch channel 422, and the inlet 423 is mirror-symmetrical about the first plane a. The extension cavity 3 is also mirror-symmetrical about the first plane a. Furthermore, the bottom surfaces of the main channel 421 and each of the branch channels 422 coincide with the first plane a, allowing the molten metal near the second sidewall in the inlet 423 to maintain a higher flow rate and smoothly enter the upper part of the extension cavity 3. After being accelerated by the extension cavity 3, it enters the main chamber 11 at a higher flow rate. At the same time, the vertical distance between the second sidewall of the second chamber 32 and the second sidewall of the main chamber 11 does not exceed the distance between the first sidewall and the second sidewall of the second chamber 32. The vertical distance of the wall is half that of the main body chamber 11, which makes the distance between this part of the molten metal and the second side wall of the main body chamber 11 smaller. The second side wall of the main body chamber 11 can guide this part of the liquid to climb upward, further helping this part of the molten metal to reach the top of the main body chamber 11 faster, and thus fill the second side wing chamber 13 faster. The molten metal near the first side wall of the inlet 423 has a lower flow rate and will further converge at the bottom of the extension chamber 3, and then accelerate to flow towards the main body chamber 11. This mainly realizes the filling of the main body chamber 11 and the first side wing chamber 12. The molten metal with different flow rates achieves partitioned filling, which further accelerates the overall filling progress of the molten metal.

[0048] The first chamber 31 in this embodiment specifically includes an expansion section 311 and a narrowing section 312. The expansion section 311 is connected to the feed inlet 423, and the vertical distance between the first and second sidewalls of the expansion section 311 gradually increases in the direction away from the feed inlet 423. The narrowing section 312 is connected to the second chamber 32, and the vertical distance between the first and second sidewalls of the narrowing section 312 gradually increases in the direction away from the second chamber 32. The first and second sidewalls of the expansion section 311 are arranged sequentially and opposite to each other in the second preset direction, and the first and second sidewalls of the narrowing section 312 are arranged sequentially and opposite to each other in the second preset direction. The ratio of the vertical distance between the first and second sidewalls of the feed inlet 423 to the maximum vertical distance between the first and second sidewalls of the expansion section 311 is 1 / 3 to 2 / 3, so that the metal fluid flowing through the first chamber 31 is buffered. The first and second sidewalls of the narrowing section 312 each include an inclined surface b, a first curved surface c, and a second curved surface d arranged sequentially along the first preset direction. The second curved surface d is connected to the second chamber 32. The first curved surface c is a convex arc surface, and the second curved surface d is a concave arc surface. The projection of the feed inlet 423 along the first preset direction is located on the first curved surface c. Part of the metal fluid flowing through the first curved surface c is accelerated under the guidance of the first curved surface c and the second curved surface d, and enters the cavity 1 through the second chamber 32. Part of the fluid will converge in the first chamber 31 and then accelerate to flow into the second chamber 32. In this embodiment, the slope of the inclined surface b of the narrowing section 312 is not greater than 45°, and the length ratio of the expansion section 311 to the narrowing section 312 along the first preset direction is 1 / 8 to 1 / 4. The length ratio of the expansion section 311 to the second chamber 32 along the first preset direction is 1 / 4 to 1 / 2, so that the metal fluid continuously fills the second chamber 32 and maintains a high flow rate towards the main chamber 11.

[0049] The die-casting mold flow channel feeding structure of this embodiment can prevent molten metal from eroding the mold, protect the mold from cracking, extend the mold's service life, and reduce the manufacturing cost of thin-walled castings.

[0050] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A die casting mold flow channel feeding structure for thin-walled die castings, characterized in that, It includes a mold cavity, an overflow cavity, an extension cavity, and a die-casting runner system, wherein the die-casting runner system, the extension cavity, the mold cavity, and the overflow cavity are arranged sequentially along a first preset direction; The extended cavity includes a first chamber and a second chamber that are interconnected. The die-casting flow channel system has multiple branch flow channels arranged side by side. Each branch flow channel has a feed inlet, which is connected to the first chamber. The mold cavity has a main chamber that is connected to the second chamber. In a second preset direction perpendicular to the first preset direction, the distance between the two side walls of the feed inlet is greater than the distance between the two side walls of the main chamber; The projection of the feed inlet along the first preset direction is located inside the first cavity; The projection of the second chamber along the first preset direction is located within the main body chamber.

2. The die casting mold flow channel feeding structure for thin-walled die castings as described in claim 1, characterized in that, The first sidewall of the second chamber is arranged parallel to the first sidewall of the main chamber, and the second sidewall of the second chamber is arranged parallel to the second sidewall of the main chamber. The first sidewall and the second sidewall of the second chamber are arranged sequentially and opposite to each other in the second preset direction. The first sidewall and the second sidewall of the main chamber are arranged sequentially and opposite to each other in the second preset direction. The cavity further includes a first wing cavity that intersects and communicates with the main cavity. The first wing cavity is located at one end of the main cavity near the extension cavity. The first wing cavity extends from the main cavity in a second predetermined direction. The vertical distance between the first side wall of the second cavity and the first side wall of the main cavity is greater than the vertical distance between the second side wall of the second cavity and the second side wall of the main cavity.

3. The die casting mold flow channel feeding structure for thin-walled die castings as described in claim 1, characterized in that, The extension cavity is continuously arranged in a third preset direction, which is perpendicular to the first preset direction and the second preset direction.

4. The die casting mold flow channel feeding structure for thin-walled die castings as described in claim 1, characterized in that, The first chamber includes an expansion section and a narrowing section. The expansion section is connected to the feed inlet, and the vertical distance between the first sidewall and the second sidewall of the expansion section gradually increases in the direction away from the feed inlet. The narrowing section is connected to the second chamber, and the vertical distance between the first sidewall and the second sidewall of the narrowing section gradually increases in the direction away from the second chamber. The first sidewall and the second sidewall of the expansion section are arranged sequentially and opposite to each other in the second preset direction. The first sidewall and the second sidewall of the narrowing section are arranged sequentially and opposite to each other in the second preset direction. The first and second sidewalls of the narrowing section each include an inclined surface, a first curved surface, and a second curved surface arranged sequentially along the first preset direction. The second curved surface is connected to the second chamber. The first curved surface is a convex arc surface, and the second curved surface is a concave arc surface. The projection of the feed port along the first preset direction is located on the first curved surface.

5. The die casting mold runner feeding structure for thin-walled die castings as described in claim 4, characterized in that, The slope of the inclined plane shall not exceed 45°; The length ratio of the expansion segment to the narrowing segment along the first preset direction is 1 / 8 to 1 / 4; The length ratio of the expansion section to the second chamber along the first preset direction is 1 / 4 to 1 / 2; The ratio of the vertical distance between the first and second sidewalls of the feed inlet to the maximum vertical distance between the first and second sidewalls of the expansion section is 1 / 3 to 2 / 3.

6. The die casting mold flow channel feeding structure for thin-walled die castings as described in claim 2, characterized in that, The vertical distance between the second sidewall of the second chamber and the second sidewall of the main chamber does not exceed 1 / 2 of the vertical distance between the first and second sidewalls of the second chamber.

7. The die casting mold flow channel feeding structure for thin-walled die castings as described in claim 1, characterized in that, The feed inlet is mirror-symmetrical about the first plane, and the extension cavity is mirror-symmetrical about the first plane.

8. The die casting mold flow channel feeding structure for thin-walled die castings as described in claim 2, characterized in that, The cavity also includes a second wing cavity that intersects and communicates with the main cavity. The second wing cavity is located at the end of the main cavity away from the extension cavity. The second wing cavity extends from the main cavity in a second preset direction. The second cavity communicates with the first wing cavity. The overflow cavity communicates with the second wing cavity.

9. The die casting mold runner feeding structure for thin-walled die castings as described in claim 7, characterized in that, The die-casting runner system further includes a main runner and a forward runner assembly. The main runner is connected to the main runner. The forward runner assembly is mirror-symmetrical about the axis of the main runner and includes the main runner and the branch runners. The branch runners are located on the side of the main runner away from the main runner. Each branch runner is arranged along the flow direction of the main runner, and each branch runner is intersected and connected to the main runner. The cross-sectional area of ​​the main flow channel gradually decreases along its flow direction. The distance between the first and second sidewalls of each branch flow channel, which are arranged sequentially and oppositely in the second preset direction, is equal. On the same cross-section, the farther the branch flow channel is from the main flow channel, the smaller the cross-sectional area of ​​the branch flow channel.

10. The die casting mold flow channel feeding structure for thin-walled die castings as described in claim 9, characterized in that, The first sidewall of the branch channel coincides with the first plane.

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