Forming die and forming process for internal and external elbows of bus duct

Abstract

The invention relates to the technical field of power distribution equipment manufacturing, and discloses a bus duct inner and outer elbow forming mold and a forming technology.The forming mold comprises an upper mold body and a lower mold body, the upper mold body and the lower mold body are closed to form a sealed cavity provided with an inner elbow forming area and an outer elbow forming area, the lower mold body is provided with a feeding flow path composed of a pouring opening, a pouring head and a sprue, and the pouring head is provided with a slope inclining downwards; the sprue is provided with a multi-stage buffer part, the tail end of the cavity is communicated with an overflow groove, and the tail end of the sprue is provided with a shunting structure; the forming process comprises the steps of mold closing and liquid injection, slope guiding of metal liquid layering, multi-stage buffering flow stabilization, flow division and synchronous cavity filling, discharging of gas slag into an overflow groove, cooling, mold opening and part taking. Through collaborative design of the flow path structure and the forming process, steady-flow conveying and pure filling of molten metal are achieved, the defects of casting air holes and slag inclusion are reduced, the forming quality and size consistency of the bus duct elbow are improved, and the production efficiency and product reliability of power distribution equipment connecting pieces are improved.

Description

Technical Field

[0001] This invention relates to the field of power distribution equipment manufacturing technology, and in particular to a forming mold and forming process for inner and outer bends of busbar trunking. Background Technology

[0002] Busbar trunking, as a highly efficient power transmission and distribution device, is widely used in the power supply systems of modern high-rise buildings and industrial facilities. The inner and outer elbows of the busbar trunking, as key conductive and structural components connecting the straight sections of the busbar trunking and realizing the turning of the line, are usually made of aluminum alloy or copper alloy materials and integrally formed by die casting. The die casting process has the characteristics of high production efficiency and good dimensional consistency, and is currently the main processing method for manufacturing irregular metal connectors.

[0003] Existing busbar elbow die-casting molds typically include a moving mold and a fixed mold. During die-casting production, molten metal is injected through the injection system via the mold's inlet, guided by the runner system, and then filled into the cavity. The product is then cooled and solidified under pressure to obtain the finished product. Conventional mold runner designs often focus on shortening the filling time, typically using straight-through runners or simple branching structures to directly connect the gating port and the cavity, ensuring that the molten metal can quickly fill the complex-shaped elbow cavity.

[0004] Because conventional molds lack effective buffering and flow stabilization structures in their flow channels, the high-temperature molten metal impacts the cavity entrance at extremely high speeds under injection pressure, causing severe turbulence and splashing in the molten metal flow. This severe turbulence easily draws air from the flow channel or cavity into the molten metal, forming porosity or pinhole defects after the casting cools. At the same time, because conventional gating systems lack physical isolation designs for cold metal and oxide scale, cold material and impurities at the molten metal flow head enter the busbar elbow forming area directly with the main fluid. The mixing of impurities leads to a decrease in the internal density of the product and the formation of cold shuts or inclusions on the casting surface, seriously affecting the electrical conductivity and mechanical strength of the busbar elbow. Summary of the Invention

[0005] The purpose of this invention is to provide a forming mold and forming process for inner and outer bends of busbar trunking, which solves the problems of conventional molds lacking an effective buffer and flow stabilization structure in the direct flow channel, resulting in turbulent flow and air entrapment of molten metal, and the lack of a design to isolate cold contaminated metal and oxide scale in the gating system, leading to product defects and performance impairment.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A busbar trunking inner and outer bend forming mold includes an upper mold and a lower mold. When the upper mold and the lower mold are closed, they form a sealed cavity. The cavity includes an inner bend forming area and an outer bend forming area. The upper mold and the lower mold cooperate to form a feeding flow path, which includes a pouring gate, a pouring head, and a sprue in sequence. The pouring gate is located on the upper mold and communicates with the outside of the mold. The pouring head and the sprue are located on the top of the lower mold. The end of the pouring gate is connected to the sprue through the pouring head. The sprue extends and communicates with the entrance of the cavity. The bottom surface of the pouring head is provided with a height difference structure, which forms a slope that slopes downward along the direction of the flow of liquid metal. One end of the slope is connected to the pouring port, and the other end of the slope is connected to the starting end of the straight pouring channel. A buffer section is provided on the extension path of the sprue, the buffer section being located on the downstream side of the ramp and on the upstream side of the cavity inlet. Preferably, the buffer section is constructed as a cavity structure recessed into the bottom surface or side wall of the sprue, and the depth of the cavity structure is greater than the depth of the connection between the sprue and the cavity.

[0007] Preferably, overflow channels are connected to the inner bend forming area and the outer bend forming area at the ends away from the sprue, respectively; the overflow channels are connected to the cavity through overflow ports, and the ends of the overflow channels are connected to venting channels extending to the outside of the mold.

[0008] Preferably, the number of buffer sections is at least four, and the four buffer sections are arranged at intervals along the length direction of the straight gating channel.

[0009] Preferably, the cavity is provided with rib forming positions; the overflow groove is provided at the intersection of the rib forming positions and at the end of the molten metal filling of the cavity away from the feed flow path, and the volume of the overflow groove is configured to accommodate the molten metal flowing in from the cavity.

[0010] Preferably, the inner bend forming area and the outer bend forming area are symmetrically distributed about the center line of the sprue. The end of the sprue is provided with a flow divider structure, which leads to the ingate of the inner bend forming area and the outer bend forming area respectively.

[0011] Preferably, the surface of the slope is a smooth transition surface, and the slope connects the plane where the pouring head is located with the plane where the straight pouring channel is located to form a stepped structure.

[0012] Preferably, the upper mold has a mating surface corresponding to the position of the pouring head and the sprue. When the upper mold and the lower mold are closed, the mating surface of the upper mold, together with the pouring head, sprue and buffer of the lower mold, form a closed metal liquid flow path.

[0013] Preferably, the cross-sectional area of ​​the buffer section is larger than the cross-sectional area of ​​the non-buffered section region of the sprue.

[0014] A forming process for a busbar trunking inner and outer elbow forming mold includes the following steps: The upper and lower molds are closed to form a sealed cavity, and molten metal is injected into the mold through the pouring gate; The injected molten metal enters the pouring head and flows down the slope into the straight pouring channel. The height difference structure guides the molten metal to flow in layers, so that the heavier cold-stained metal is retained at the bottom of the flow path. The molten metal entering the sprue flows through four buffer sections set in the sprue in sequence. After filling the cavity of the buffer section, the molten metal continues to flow towards the cavity. After passing through the buffer section, the molten metal is simultaneously filled into the inner elbow forming area and the outer elbow forming area via the diversion structure. During the filling process, the air, volatile gases and cold molten metal located at the flow head in the cavity are pushed to the end of the cavity and discharged into the overflow groove through the overflow port; After the molten metal cools and solidifies in the die-casting mold, the upper and lower molds are opened, and the molded product containing the inner and outer bends of the busbar groove is taken out.

[0015] In summary, the present invention has at least one of the following beneficial technical effects: 1. This invention adopts a downward sloping design on the bottom surface of the pouring head, combined with the height difference structure formed between the slope and the straight channel, and uses the principles of gravity and fluid mechanics to guide the molten metal. The height difference structure helps to make the heavy, oxide-staining cold sludge metal adhere to the bottom layer of the flow path or stay there, thereby improving the purity of the molten metal entering the cavity and improving the material quality of the final product.

[0016] 2. This invention provides multiple buffer sections along the extension path of the direct current channel, with the depth of the buffer sections greater than the depth of the channel connection. The cavity structure formed by the buffer sections preferentially receives the high-speed flowing molten metal. The buffer sections help to consume the impact kinetic energy of the fluid, thereby reducing the flow velocity and smoothing turbulence, which improves the filling flow pattern of the molten metal, reduces the occurrence of air entrapment, and lowers the probability of porosity defects inside the product.

[0017] 3. This invention utilizes a flow-splitting structure at the end of a single direct current channel, combined with a symmetrical layout of the inner and outer elbow forming areas, to simultaneously complete the injection molding of two elbows of different specifications in one mold. The flow-splitting structure and symmetrical layout not only improve production efficiency but also help ensure a relative balance of pressure and speed in the two cavities during the filling process, thereby improving the consistency of product dimensional accuracy in mass production.

[0018] 4. The present invention collects residual gas and cold metal contamination pushed to the front of the fluid during the final stage of filling by setting an overflow groove and an exhaust groove at the end of the cavity away from the direct flow channel; the overflow groove and exhaust groove help to remove impurities and air bubbles that are prone to defects from the product forming area, thereby ensuring the compactness of the busbar elbow body structure and helping to improve the surface finish of the product. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the busbar groove inner and outer elbow forming mold in an embodiment of the present invention; Figure 2 This is a schematic diagram of the cavity structure in an embodiment of the present invention; Figure 3 This is a schematic diagram of the upper mold in an embodiment of the present invention; Figure 4 for Figure 3 Enlarged diagram of A in the middle; Figure 5 This is a schematic diagram of the lower mold structure in an embodiment of the present invention; Figure 6 for Figure 5 Enlarged diagram of B in the diagram.

[0020] The components are: 1. Upper mold; 2. Lower mold; 3. Cavity; 31. Inner bend forming area; 32. Outer bend forming area; 4. Pour gate; 5. Pour head; 51. Slope; 6. Sprue; 61. Buffer section; 7. Overflow groove. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see the appendix Figure 1 -Appendix Figure 6 The present invention provides a busbar trunking inner and outer bend forming mold, including an upper mold 1 and a lower mold 2. After the upper mold 1 and the lower mold 2 are closed, a sealed cavity 3 is formed. The cavity 3 includes an inner bend forming area 31 and an outer bend forming area 32. The upper mold 1 and the lower mold 2 cooperate to form a feeding flow path, which includes a pouring port 4, a pouring head 5 and a sprue 6 in sequence. The pouring port 4 is located on the upper mold 1 and communicates with the outside of the mold. The pouring head 5 and the sprue 6 are located on the top of the lower mold 2. The end of the pouring port 4 is connected to the sprue 6 through the pouring head 5. The sprue 6 extends and communicates with the entrance of the cavity 3. The bottom surface of the pouring head 5 is provided with a height difference structure, which forms a slope 51 that slopes downward along the direction of the flow of liquid metal. One end of the slope 51 is connected to the pouring port 4, and the other end of the slope 51 is connected to the starting end of the straight pouring channel 6. A buffer section 61 is provided on the extension path of the sprue 6. The buffer section 61 is located on the downstream side of the ramp 51 and on the upstream side of the cavity 3 entrance. The surface of the ramp 51 is a smooth transition surface. The ramp 51 connects the plane where the pouring head 5 is located with the plane where the sprue 6 is located to form a stepped structure. When the upper mold 1 and the lower mold 2 are closed, the mating surface of the upper mold 1, the pouring head 5 of the lower mold 2, the sprue 6 and the buffer section 61 together form a closed metal liquid flow path.

[0023] Specifically, through the coordinated action of the upper mold 1, lower mold 2, pouring head 5, ramp 51, sprue 6, buffer section 61, and the mating surface of the upper mold 1, the sealing construction and initial flow regulation before the molten metal is transported are completed. The working process is as follows: Before the die casting operation, the upper mold 1 and lower mold 2 are precisely closed. After the two are fitted together, a sealed cavity 3 is formed. The inner bend forming area 31 and the outer bend forming area 32 in the cavity 3 are simultaneously in a state of waiting to be filled. At the same time, the mating surface of the upper mold 1 corresponding to the pouring head 5 and sprue 6 is tightly fitted with the pouring head 5, sprue 6, and buffer section 61 of the lower mold 2, together forming a gapless closed molten metal flow path, which structurally blocks the molten metal leakage channel and prevents external air from seeping into the flow path. During die casting, high-temperature molten metal is injected through the pouring port 4 under the pressure of the injection and then enters the pouring head 5 area. Because the bottom surface of the pouring head 5 has a height difference structure, it forms a slope 51 that slopes downward along the direction of molten metal flow. The surface of the slope 51 is a smooth transition surface, and the molten metal will flow naturally downward along the slope 51. Furthermore, because the slope 51 connects the plane where the pouring head 5 is located with the plane where the sprue 6 is located to form a stepped structure, the molten metal can achieve a smooth transition from the pouring head 5 to the sprue 6 without impact splashing or local turbulence caused by abrupt changes in the plane. The molten metal flowing through the slope 51 continues to flow into the sprue 6, passing through the buffer section 61 located downstream of the slope 51 and upstream of the cavity 3 entrance, which prepares for further flow regulation before entering the cavity 3. After the molten metal arrives at the buffer section 61, its key layout along the extension path of the sprue 6 further optimizes the flow pattern following the smooth guidance described earlier. The specific process is as follows: The buffer section 61 is precisely positioned at the transition point between the downstream of the ramp 51 and the upstream of the cavity 3 entrance, enabling targeted flow pattern control of the molten metal after being guided by the ramp 51. At this time, the molten metal continues to flow along the sprue 6 and enters the buffer section 61 area. Relying on the closed flow path enclosed by the mating surface of the upper mold 1 and the structure of the lower mold 2, the molten metal will not leak or overflow. It can flow completely through the buffer section 61 within the preset flow path, laying the flow pattern foundation for the subsequent filling operation into the cavity 3, and ensuring that the molten metal arrives at the cavity 3 entrance in a stable state.

[0024] Please see the appendix Figure 5 - Appendix Figure 6 The buffer section 61 is constructed as a cavity structure recessed in the bottom surface or side wall of the sprue 6, and the depth of the cavity structure is greater than the depth at the connection between the sprue 6 and the cavity 3.

[0025] Specifically, the flow of molten metal is controlled through the cavity structure and depth design of the buffer section 61. When the molten metal flows along the sprue 6 towards the inlet of the cavity 3, it will naturally flow into the buffer section 61 area. Because the buffer section 61 is a cavity structure recessed into the bottom or side wall of the sprue 6, the molten metal cannot directly and quickly flow through the sprue 6 and must first gradually fill the internal space of the cavity. Relying on the closed molten metal flow path enclosed by the mating surface of the upper mold 1 and the lower mold 2, the molten metal filling the cavity will not overflow, leak, or divert, and the flow transition can be completely completed within the limited space of the cavity. The depth of the cavity structure is greater than the depth at the connection between the sprue 6 and the cavity 3, creating a deeper internal space. The filled molten metal must overcome this depth difference to continue flowing towards the cavity 3, further slowing the flow rate. The volume effect of the cavity simultaneously absorbs the residual impact energy of the molten metal, forcing a steady decrease in its flow velocity. This also prolongs the residence time of the molten metal in the buffer section 61, effectively suppressing localized turbulence that can easily occur during the flow process, ensuring that the molten metal reaches the connection between the sprue 6 and the cavity 3 in a stable flow state.

[0026] Please see the appendix Figure 6 Overflow grooves 7 are connected to the ends of the inner bend forming area 31 and the outer bend forming area 32, which are far from the straight sprue 6. The overflow groove 7 is connected to the cavity 3 through the overflow port, and the end of the overflow groove 7 is connected to an exhaust groove extending to the outside of the mold.

[0027] Specifically, the molten metal flows along the sprue 6 into the cavity 3, gradually filling the inner bend forming zone 31 and the outer bend forming zone 32. As the molten metal continues to advance within the forming zones, the air originally retained in the cavity 3, the volatile gases generated by the release agent, and the cold sludge from the runner flowing with the molten metal are gradually pushed to the end of the forming zones away from the sprue 6 by the continuously advancing molten metal. The overflow trough 7 corresponds to this end position of the two forming zones and is connected to the cavity 3 through the overflow port. The gas-slag mixture pushed here will naturally flow into the overflow trough 7 through the overflow port, separating from the pure molten metal being filled in the forming zones.

[0028] In the gas-slag mixture flowing into the overflow tank 7, the liquid cold slag metal will remain in the overflow tank 7, while the gas will be discharged out of the mold through the venting channel connected to the end of the overflow tank 7. This process can effectively prevent gas from stagnating in the cavity 3 and forming pores, while preventing cold slag metal from mixing into the casting body, ensuring the filling quality of the molten metal in the two forming zones.

[0029] Please see the appendix Figure 6 The number of buffer sections 61 is at least 4, and the 4 buffer sections 61 are arranged at intervals along the length of the straight runner 6.

[0030] Specifically, after the molten metal flows into the sprue 6, it will flow sequentially through four buffer sections 61 arranged at intervals along the length of the sprue 6. The molten metal cannot directly and quickly flow through the sprue 6, but needs to fill the cavity structure of each buffer section 61 one by one. Each time it flows through a buffer section 61, its impact kinetic energy will be partially absorbed by the cavity structure, and the flow rate will slow down accordingly. Through the sequential action of the four buffer sections 61, the impact kinetic energy of the molten metal is continuously consumed, the flow rate is gradually and steadily reduced, and the local turbulence generated during the flow process is also suppressed layer by layer. The spaced arrangement of the four buffer sections 61 creates a hierarchical buffering effect for the flow regulation of the molten metal in the sprue 6, avoiding the flow turbulence caused by a sudden drop in flow rate that is common with a single buffer section. This ensures that the molten metal remains stable throughout the entire sprue 6 process, and flows steadily towards the inlet of the cavity 3.

[0031] Please see the appendix Figure 5 -Appendix Figure 6 The cavity 3 is provided with rib forming positions; the overflow groove 7 is provided at the intersection of the rib forming positions and at the end of the molten metal filling of the cavity 3 away from the feed flow path, and the volume of the overflow groove 7 is configured to accommodate the molten metal flowing from the cavity 3.

[0032] Specifically, during the process of filling the cavity 3 with molten metal, the continuously pushed air, volatile gases and cold sludge molten metal from the flow head tend to accumulate in relatively enclosed spaces such as the intersection of the ribs of the cavity 3 and the depth of the cavity. The overflow trough 7 is precisely located in such areas where gas and slag tend to accumulate, and can accurately and comprehensively receive the gas and slag mixture that has accumulated there. The gas and slag mixture can flow smoothly into the overflow trough 7 through the overflow port, and complete the separation from the pure molten metal in the forming area of ​​the cavity 3. The overflow trough 7 is specially configured to fully accommodate the liquid metal flowing from the cavity 3. All the cold sludge metal flowing in can be retained inside the overflow trough 7, preventing the cold sludge metal from overflowing back into the molding area of ​​the cavity 3 due to insufficient volume. At the same time, it also provides sufficient space for the gas to flow upward in the overflow trough 7 and be discharged through the exhaust trough, ensuring the orderly and smooth process of gas and slag collection and discharge, and avoiding gas and slag residue in the molding area of ​​the cavity 3.

[0033] Please see the appendix Figure 6 The inner bend forming area 31 and the outer bend forming area 32 are symmetrically distributed with the center line of the straight sprue 6 as the axis of symmetry. The end of the sprue 6 is provided with a flow branching structure, which leads to the ingate of the inner bend forming area 31 and the outer bend forming area 32 respectively.

[0034] Specifically, after the molten metal is buffered and stabilized by the sprue 6, it flows to the end of the sprue 6 and contacts the flow divider structure. The flow divider structure evenly splits the single stream of molten metal into two streams with consistent flow patterns, which flow to the ingates corresponding to the inner bend forming area 31 and the outer bend forming area 32, respectively. Since the inner bend forming area 31 and the outer bend forming area 32 are symmetrically distributed about the centerline of the sprue 6, the flow path length and flow resistance of the two streams of molten metal are consistent, allowing them to enter the two forming areas simultaneously and begin the filling operation. This symmetrical distribution and diversion structure ensures that the filling pressure and speed of the two molten metal streams remain balanced, preventing one side from filling too quickly and the other too slowly. This effectively prevents defects such as casting deformation and wall thickness deviation caused by uneven filling. Furthermore, by using a single mold to simultaneously form two elbow products, overall production efficiency is improved while ensuring consistent product dimensional accuracy.

[0035] Please see the appendix Figure 6 The cross-sectional area of ​​the buffer section 61 is larger than the cross-sectional area of ​​the non-buffered section area of ​​the straight runner 6.

[0036] Specifically, when the molten metal flows from the non-buffered area of ​​the sprue 6 to the buffered area 61, the cross-sectional area of ​​the buffered area 61 is larger than that of the non-buffered area of ​​the sprue 6. As the cross-sectional area increases, the flow space in the flow channel widens, the flow cross-section of the molten metal expands synchronously, and the flow velocity naturally slows down as the flow space widens. The local eddies that are easy to generate when flowing in a narrow channel will also be effectively dissipated in the widened space. The wider cross-sectional area further enhances the cavity capacity of the buffer section 61, enabling it to absorb the impact energy of the molten metal more fully. The flow of the molten metal within the buffer section 61 is smoother, preventing flow obstruction due to the narrow flow channel. When the molten metal flows through the buffer section 61 and then towards the non-buffered area of ​​the sprue 6 and the cavity 3, the flow pattern remains stable, preventing turbulence caused by abrupt changes in the flow channel cross-section and ensuring a stable flow of the molten metal.

[0037] Please see the appendix Figure 1 -Appendix Figure 6 A forming process for a busbar trunking inner and outer elbow forming mold, comprising the following steps: The upper mold 1 and the lower mold 2 are closed to form a sealed cavity 3, and the molten metal is injected into the mold through the pouring port 4; The injected molten metal enters the pouring head 5 and flows down the slope 51 into the straight pouring channel 6. The height difference structure guides the molten metal to flow in layers, so that the heavier cold sludge metal is retained at the bottom of the flow path. The molten metal entering the sprue 6 flows through the four buffer sections 61 set in the sprue in sequence. After the molten metal fills the cavity of the buffer section 61, it continues to flow towards the cavity. After passing through the buffer section 61, the molten metal is simultaneously filled in the inner elbow forming area 31 and the outer elbow forming area 32 via the diversion structure. During the filling process, the air, volatile gases and cold molten metal in the cavity 3 are pushed to the end of the cavity 3 and discharged into the overflow groove 7 through the overflow port. After the molten metal cools and solidifies in the die-casting mold, open the upper mold 1 and the lower mold 2, and take out the molded product containing the inner and outer bends of the busbar groove.

[0038] Specifically, the upper mold 1 and lower mold 2 are first closed, forming a sealed cavity 3 to prevent subsequent leakage of molten metal and infiltration of external air, providing a sealed foundation for die casting. Then, the high-temperature molten metal is injected into the mold through the gating port 4 under injection pressure, and directly enters the casting head 5 area. Under the combined action of gravity and injection pressure, the molten metal flows downwards along the slope 51 at the bottom of the casting head 5. The slope 51 creates a natural stratified flow, with heavier, oxide-laden molten metal remaining or adhering to the bottom layer due to gravity, while the upper layer is relatively pure molten metal, thus initially separating impurities from pure molten metal. The molten metal continues to flow into the sprue 6, passing sequentially through four spaced buffer sections 61. Each buffer section 61 needs to be filled, gradually consuming impact energy during the filling process, slowing the flow rate layer by layer, and continuously smoothing the flow pattern to ensure stability when flowing towards the cavity 3.

[0039] After being buffered and stabilized, the molten metal flows to the end of the sprue 6, where it is evenly split into two streams with consistent flow patterns by a flow divider. These streams flow to the ingates of the inner bend forming area 31 and the outer bend forming area 32, respectively. Because the two forming areas are symmetrically distributed with the center line of the sprue 6 as the axis of symmetry, the two streams fill synchronously, maintaining a balance in pressure and velocity. During the filling process, the air, mold release agent volatiles, and cold metal contamination from the runner that remain in the cavity 3 are pushed to the end of the cavity 3 by the continuously advancing molten metal and discharged into the overflow groove 7 through the overflow port. The cold metal contamination remains in the groove, while the gas is discharged from the mold through the venting groove. After the molten metal has been held under pressure, cooled, and solidified in the mold to form complete inner and outer bends of the busbar groove, the upper mold 1 and lower mold 2 are opened, and the molded product is removed. The entire process ensures both product molding quality and efficient synchronous production.

[0040] Working principle: When the mold is working, the upper mold 1 and the lower mold 2 are closed first, and the mating surfaces of the two are tightly fitted to form a sealed cavity 3, in which the inner bend forming area 31 and the outer bend forming area 32 are in a state of waiting to be filled. High-temperature molten metal is injected through the pouring port 4 and then enters the pouring head 5. Under the action of gravity and injection pressure, the molten metal flows down the slope 51 at the bottom and enters the straight pouring channel 6. During this process, the height difference structure formed by the slope 51 is used to physically guide the fluid, so that the heavy, cold-stained metal mixed with oxide scale and impurities tends to stay or adhere to the bottom of the flow path, while the purer molten metal is located in the upper layer, thus achieving preliminary fluid stratification and impurity isolation. After the molten metal has been initially layered, it enters the sprue 6 and flows sequentially through the four buffer sections 61 set in the flow channel along the extended path. Since the buffer section 61 is constructed as a cavity structure with a large depth, the front end of the high-speed flowing molten metal will preferentially fall and fill these cavities. Through the volume effect of the cavity, the impact kinetic energy of the fluid is absorbed by the water hammer effect, which effectively reduces the flow rate of the molten metal and smooths the turbulence, thereby creating conditions for subsequent smooth filling and reducing the generation of air entrapment and porosity defects. After being buffered and stabilized, the molten metal flows to the end of the sprue 6 and is evenly distributed through the flow distribution structure. It is then simultaneously filled into the inner bend forming area 31 and the outer bend forming area 32 through the ingate, ensuring that the filling pressure and speed of the two cavities 3 are balanced and avoiding casting deformation caused by uneven filling. As the molten metal continues to advance in the cavity 3, the residual air, volatile gases from the release agent, and cold sludge metal at the front of the fluid are pushed to the end position away from the feed end and discharged into the overflow trough 7 through the overflow port. The overflow trough 7 is used to accommodate the above-mentioned gas and slag inclusions, thereby ensuring the compactness and surface smoothness of the busbar elbow body structure. After filling is complete, the molten metal is cooled and solidified under pressure. Then, the upper mold 1 and the lower mold 2 are separated, and the molded product containing the inner and outer bends of the busbar groove is taken out, thus completing the entire die casting process.

Claims

1. A forming mold for inner and outer bends of busbar trunking, characterized in that, It includes an upper mold (1) and a lower mold (2). When the upper mold (1) and the lower mold (2) are closed, a sealed cavity (3) is formed. The cavity (3) includes an inner bend forming area (31) and an outer bend forming area (32). The upper mold (1) and the lower mold (2) cooperate to form a feeding flow path, which includes a pouring port (4), a pouring head (5) and a sprue (6) in sequence. The pouring port (4) is located on the upper mold (1) and communicates with the outside of the mold. The pouring head (5) and the sprue (6) are located on the top of the lower mold (2). The end of the pouring port (4) is connected to the sprue (6) through the pouring head (5). The sprue (6) extends and communicates with the entrance of the cavity (3). The bottom surface of the pouring head (5) is provided with a height difference structure, which forms a slope (51) that slopes downward along the direction of the flow of liquid metal. One end of the slope (51) is connected to the pouring port (4), and the other end of the slope (51) is connected to the starting end of the straight pouring channel (6). A buffer section (61) is provided on the extension path of the sprue (6), the buffer section (61) being located on the downstream side of the ramp (51) and on the upstream side of the cavity (3) entrance.

2. The busbar trunking inner and outer bend forming mold according to claim 1, characterized in that: The buffer section (61) is constructed as a cavity structure recessed in the bottom surface or side wall of the sprue (6), and the depth of the cavity structure is greater than the depth of the connection between the sprue (6) and the cavity (3).

3. The busbar trunking inner and outer bend forming mold according to claim 1, characterized in that: Overflow grooves (7) are connected to the ends of the inner bend forming area (31) and the outer bend forming area (32) away from the sprue (6). The overflow groove (7) is connected to the cavity (3) through the overflow port, and the end of the overflow groove (7) is connected to an exhaust groove extending to the outside of the mold.

4. The busbar trunking inner and outer bend forming mold according to claim 2, characterized in that: The number of buffer sections (61) is at least 4, and the 4 buffer sections (61) are arranged at intervals along the length direction of the straight gating channel (6).

5. The busbar trunking inner and outer bend forming mold according to claim 3, characterized in that: The cavity (3) is provided with a rib forming position; the overflow groove (7) is provided at the intersection of the rib forming positions and at the end of the molten metal filling of the cavity (3) away from the feed flow path, and the volume of the overflow groove (7) is configured to accommodate the molten metal flowing in from the cavity (3).

6. The busbar trunking inner and outer bend forming mold according to claim 1, characterized in that: The inner bend forming area (31) and the outer bend forming area (32) are symmetrically distributed with the center line of the straight sprue (6) as the axis of symmetry. The end of the sprue (6) is provided with a flow divider structure, which leads to the inlet gates of the inner bend forming area (31) and the outer bend forming area (32), respectively.

7. The busbar trunking inner and outer bend forming mold according to claim 1, characterized in that: The surface of the ramp (51) is a smooth transition surface, and the ramp (51) connects the plane where the pouring head (5) is located with the plane where the straight pouring channel (6) is located to form a stepped structure.

8. The busbar trunking inner and outer bend forming mold according to claim 1, characterized in that: The upper mold (1) has a mating surface corresponding to the position of the pouring head (5) and the sprue (6). When the upper mold (1) and the lower mold (2) are closed, the mating surface of the upper mold (1) together with the pouring head (5), the sprue (6) and the buffer part (61) of the lower mold (2) form a closed metal liquid flow path.

9. The busbar trunking inner and outer bend forming mold according to claim 2, characterized in that: The cross-sectional area of ​​the buffer section (61) is greater than the cross-sectional area of ​​the non-buffered area of ​​the straight runner (6).

10. A forming process for a busbar trunking inner and outer bend forming mold, characterized in that, The method applied to the busbar trunking inner and outer bend forming mold as described in any one of claims 1-9 includes the following steps: The upper mold (1) and the lower mold (2) are closed to form a sealed cavity (3), and the molten metal is injected into the mold through the pouring port (4); The injected molten metal enters the pouring head (5) and flows down the slope (51) into the straight pouring channel (6). The high and low difference structure guides the molten metal to flow in layers, so that the heavy cold sludge metal is retained at the bottom of the flow path. The molten metal entering the sprue (6) flows through the four buffer sections (61) set in the sprue in sequence. After filling the cavity of the buffer section (61), the molten metal continues to flow towards the cavity (3). After passing through the buffer section (61), the molten metal is simultaneously filled in the inner elbow forming area (31) and the outer elbow forming area (32) through the diversion structure. During the filling process, the air, volatile gases and cold molten metal in the cavity (3) and the flow head are pushed to the end of the cavity (3) and discharged into the overflow groove (7) through the overflow port; After the molten metal cools and solidifies in the die-casting mold, open the upper mold (1) and the lower mold (2) and take out the molded product containing the inner and outer bends of the busbar groove.

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