Multi-gated aluminum alloy wheel casting mold and casting method

Abstract

The present application provides a kind of multi-gate aluminum alloy wheel casting mould and pouring method, multiple edge gates are arranged on wheel rim, and a center gate is arranged in wheel core simultaneously, so that the filling time of liquid aluminum is shortened by more than half, the feeding distance is greatly reduced, the production efficiency of filling is improved, and the shrinkage porosity is reduced; since the cooling process starts from multiple places in outer rim, inner rim and spoke, and sequentially solidifies towards the rim and wheel core, combined with the opening of multiple groups of annular cooling water channels, the crystallization and solidification time of the wheel is greatly shortened, the internal organization density of the casting is improved, and the elongation and strength of the spoke, wheel core, inner and outer rim are greatly improved.

Description

Technical Field

[0001] This invention relates to aluminum alloy molds and forming processes. Background Technology

[0002] Currently, traditional low-pressure casting of aluminum alloy wheels mostly employs a center-gating process. Molten aluminum enters the mold cavity through a gate located at the center of the wheel, flows through the spokes, and then fills the rim until the mold is complete. During solidification, the center of the spokes must provide feeding to the distal rim and spoke roots, so it cannot cool too quickly. This delays the solidification of the spokes, affecting the mechanical properties of the aluminum alloy wheel material, particularly the generally low elongation of the spokes, directly impacting the overall quality of the wheel. For some special market products, due to their design, only a smaller center gate can be designed, which further limits the gate's feeding capacity for the entire wheel, thus affecting the product's internal quality.

[0003] To improve the current situation, some have proposed setting separate gates at the wheel center and rim, from which molten aluminum is injected into the mold cavity, a method known as the three-gate casting method. However, while the existing three-gate casting process meets the requirements for small-gate products and improved spoke performance to some extent, in actual production, it still suffers from problems such as low die-casting efficiency and localized low mechanical properties. Furthermore, it cannot effectively address the formation of oxide inclusions. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and to propose a low-pressure casting mold and casting process for aluminum alloy wheels.

[0005] To achieve the above objectives, the technical solution of this invention is as follows: a multi-gate aluminum alloy wheel casting mold includes a top mold plate, a top mold, a bottom mold, a bottom mold plate, a runner cone, several side molds, and several sprue plates. The runner cone is disposed on the top mold, which is connected to the top mold plate. The sprue plates and the bottom mold are both disposed on the bottom mold plate, and the side molds are disposed between the top mold plate and the bottom mold plate. A central sprue cup matching the central sprue is disposed at the center of the bottom mold plate, and side sprue cups matching the side sprue plates are disposed on the sprue plates. The upper ends of the sprue cups are connected to the central sprue and the side sprue respectively, and the lower ends of the sprue cups are connected to the riser pipe inserted into the holding furnace. The top mold, runner cone, side mold, sprue plate and bottom mold are combined to form the casting blank cavity of the wheel hub. The blank cavity includes several side runner forming cavities, rim forming cavities, spoke forming cavities and wheel center forming cavities. The top mold is provided with an annular cooling water channel corresponding to the inner rim position, and the bottom mold is provided with annular cooling water channels corresponding to the middle of the spokes, the outer rim and the wheel center.

[0006] The size of the center gate is set as follows: The size of the side gate is set as follows:

[0007] The side gating system is a funnel-shaped gating system that radiates outwards from the gating gate toward the rim. The lower edge of the gating system is located 20-50mm above the outer rim, and the upper edge of the gating system is located approximately 10-40mm below the inner rim. The span is 50-150mm, and the cross-sectional thickness of the gating system is 20mm-40mm.

[0008] The diameter of the annular water channel in the top mold is 8mm-30mm, the distance from the cavity surface is 10mm-40mm, and the water flow rate is 100-600L / hr.

[0009] The diameter of the annular water channel on the outer rim of the bottom mold is 8mm-30mm, the distance from the cavity surface is 10mm-40mm, and the water flow rate is 100-600L / hr.

[0010] The diameter of the annular water channel in the bottom mold wheel center is 8mm-20mm, the distance from the cavity surface is 20mm-40mm, and the water flow rate is 100-400L / hr.

[0011] The casting method is as follows: the molten aluminum in the holding furnace enters the blank cavity from the center gate and the side gate through multiple riser pipes under pressure, and multiple filling pressures are used. After the molten aluminum fills the cavity, pressurization and cooling begin.

[0012] During cooling, first activate the annular water cooler for the top mold, the annular water cooler for the outer rim of the bottom mold, and the annular water cooler for the center of the spokes, and then activate the annular water cooler for the center of the bottom mold.

[0013] In the multi-gate aluminum alloy wheel casting process, the liquid rising stage lasts 6-8 seconds, during which the pressure increases from 0 to 180-200 mbar. Under this pressure, the molten aluminum rises through multiple riser pipes to the top of the riser pipes.

[0014] During the first stage of filling (8-10 seconds), the pressure increases from 180-200 mbar to 220-250 mbar. During this stage, the molten aluminum is continuously filled into the bottom of the spokes 3 through multiple side gates 10 and the center gate 8 under the pressure.

[0015] During the second stage of filling (8-10 seconds), the pressure increases from 220-250 mbar to 280-340 mbar. During this stage, the molten aluminum slowly fills the spokes 3 and rim 2 under the continuous pressure.

[0016] During the pressurization phase (8-12 seconds), the pressure rapidly increases from 280-340 mbar to 700-950 mbar. This phase is after the molten aluminum fills the cavity, during which the pressure continues to increase.

[0017] The pressure holding phase lasts 30-150 seconds, with the pressure maintained at 700-950 mbar. This phase involves dimensional compensation and cooling of the cavity.

[0018] Depressurization phase: 30-60s, during which the wheel hub solidifies and depressurization occurs.

[0019] After the mold cavity is filled, immediately open the inner rim annular cooling water channel 14, the outer rim annular water cooler 16, and the spoke center annular cooling water channel 15 for 50-200 seconds at a water flow rate of 100-600 L / hr. In the latter half of the pressure holding stage, open the wheel center annular cooling water channel 17 for 20-100 seconds.

[0020] By controlling the cooling time and flow rate, the molten aluminum in the cavity crystallizes according to the cooling sequence of the mold. The crystallization starts from the outer rim, inner rim, and the middle of the spokes and proceeds outwards to the other directions until the center of the rim and the center of the wheel finally crystallize.

[0021] This invention features multiple side gating channels on the wheel rim and a central gating gate at the wheel center, thus reducing the aluminum molten filling time by more than half, significantly decreasing the feeding distance, improving filling efficiency, and reducing shrinkage. Because the cooling process starts from multiple points—the outer rim, inner rim, and the center of the spokes—and solidifies sequentially towards the rim and wheel center, coupled with the opening of multiple sets of annular cooling channels, the solidification time of the wheel is greatly shortened, improving the internal density of the casting. The elongation and strength of the spokes, wheel center, and inner and outer rims are all improved. The invention significantly improves efficiency. The use of a gating plate weakens the impact of the annular cooling of the outer rim of the bottom mold on the side gating, further enhancing the feeding capacity of the side gating and ensuring improved die-casting efficiency. During the filling process, the molten aluminum flowing from the side gating and the center gating converge at the spokes. When the convergence speed is too fast, oxide slag is easily formed. This invention, by controlling the molten aluminum filling stage in segments, ensures filling efficiency while slowing down the flow rate during the convergence, thereby reducing the risk of oxide inclusions. Simultaneously, the entire mold structure is simple, requiring only the addition of a side gating and a gating plate to a conventional low-pressure center casting process. Because multi-gating systems have strong feeding capacity, and the enhancement capacity is positively correlated with the number of gatings, the entire casting process is simple and easy to operate.

[0022] This invention enables an increase in the elongation of all parts of aluminum alloy wheels to 7%-10%, and increases die-casting efficiency to 20 pieces / hour. The casting process involved in this invention is highly efficient and easy to operate, produces castings with high material properties and uniform internal quality across all parts, while the casting equipment has low equipment costs. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the low-pressure multi-gate casting process of the present invention.

[0024] Figure 2 This is a schematic diagram of the low-pressure multi-gate blank of the present invention.

[0025] Figure 3This is a simplified top view of the low-pressure three-gate mold of the present invention.

[0026] Figure 4 This is a simplified top view of the low-pressure four-gate mold of the present invention.

[0027] Figure 5 This is a simplified top view of the low-pressure five-gate mold of the present invention.

[0028] Figure 6 This is a simplified top view of the low-pressure six-gate mold of the present invention.

[0029] Figure 7 This is a simplified top view of the low-pressure seven-gate mold of the present invention. Attached image description:

[0031] Figure 1 In the middle: 1-Top mold plate, 2-Top mold, 3-Diffusion cone, 4-Side mold, 5-Gating plate, 6-Bottom mold, 7-Bottom mold plate, 8-Center gate, 9-Center gate cup, 10-Side gate, 11-Side gate cup, 12-Lift pipe, 13-Heating furnace, 14-Inner rim annular cooling water channel, 15-Spoke annular cooling water channel, 16-Outer rim annular cooling water channel, 17-Wheel center annular cooling water channel.

[0032] Figure 2 In the middle: 18-side gating, 19-rim, 20-spoke, 21-center, 22-inner rim, 23-outer rim;

[0033] Figure 3 In the middle: 4-side mold, 5-sprue tray, 10-side sprue, 6-bottom mold;

[0034] Figure 4 In the middle: 4-side mold, 5-sprue tray, 10-side sprue, 6-bottom mold;

[0035] Figure 5 In the middle: 4-side mold, 5-sprue tray, 10-side sprue, 6-bottom mold;

[0036] Figure 6 In the middle: 4-side mold, 5-sprue tray, 10-side sprue, 6-bottom mold;

[0037] Figure 7 In the middle: 4-side mold, 5-sprue tray, 10-side sprue, 6-bottom mold; Detailed Implementation

[0038] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments.

[0039] like Figure 1As shown, a multi-gate aluminum alloy wheel casting mold includes a top mold plate 1, a top mold 2, a runner cone 3, several side molds 4, several sprue plates 5, a bottom mold 6, and a bottom mold plate 7. The runner cone 3 is disposed on the top mold 2, which is connected to the top mold plate 1. The sprue plates 5 and the bottom mold 6 are both disposed on the bottom mold plate 7, and the side molds 4 are disposed between the top mold plate 1 and the bottom mold plate 7. The bottom mold plate 7 is provided with a central sprue cup 9 that matches the central sprue 8, and the sprue plates 5 are provided with side sprue cups 11 that match the side sprues 10. The upper ends of the central sprue cup 9 and the side sprue cup 11 are respectively connected to the central sprue 8 and the side sprue 9, and the lower ends are connected to the riser pipe 12 inserted into the holding furnace 13. The top mold 2, the runner cone 3, the side molds 4, the sprue plates 5, and the bottom mold 6 are combined to form the casting blank cavity of the wheel hub.

[0040] like Figure 2 As shown, the blank cavity includes several side sprue 18 forming cavities, rim 19 forming cavities, spoke 20 forming cavities, and wheel center 21 forming cavities; the top mold 2 is provided with an inner rim annular cooling water channel 14 corresponding to the inner rim 22 position, the bottom mold is provided with a spoke annular cooling water channel 15 corresponding to the middle of the spoke 20, the outer rim 23 is provided with an outer rim annular cooling water channel 16, and the wheel center 21 is provided with a wheel center annular cooling water channel 17.

[0041] In some embodiments, combined with Figure 1 , Figure 2 , Figure 3 It is equipped with two sets of side molds 4, sprue plate 5, side sprue 10, side runner 1, and riser pipe 12, and is symmetrical from left to right.

[0042] In some embodiments, combined with Figure 1 , Figure 2 , Figure 4 It is equipped with 3 sets of side molds 4, sprue plate 5, side sprue 10, side runner 1, and riser pipe 12, which are evenly distributed in a circle.

[0043] In some embodiments, combined with Figure 1 , Figure 2 , Figure 5 It is equipped with 4 sets of side molds 4, sprue plate 5, side sprue 10, side runner 1, and riser pipe 12, which are evenly distributed in a circle.

[0044] In some embodiments, combined with Figure 1 , Figure 2 , Figure 6 Five sets of side molds 4, sprue trays 5, side sprues 10, side runners 1, and riser pipes 12 are set up and are evenly distributed in a circle.

[0045] In some embodiments, combined with Figure 1 , Figure 2 , Figure 7The system is equipped with 6 sets of side molds 4, sprue trays 5, side gates 10, side runners 1, and riser pipes 12, which are evenly distributed in a circle.

[0046] In the multi-gate aluminum alloy wheel casting process, the liquid rising stage lasts 6-8 seconds, during which the pressure increases from 0 to 180-200 mbar. Under this pressure, the molten aluminum rises through multiple riser pipes to the top of the riser pipes.

[0047] During the first stage of filling (8-10 seconds), the pressure increases from 180-200 mbar to 220-250 mbar. During this stage, the molten aluminum is continuously filled into the bottom of the spokes 3 through multiple side gates 10 and the center gate 8 under the pressure.

[0048] During the second stage of filling (8-10 seconds), the pressure increases from 220-250 mbar to 280-340 mbar. During this stage, the molten aluminum slowly fills the spokes 3 and rim 2 under the continuous pressure.

[0049] During the pressurization phase (8-12 seconds), the pressure rapidly increases from 280-340 mbar to 700-950 mbar. This phase is after the molten aluminum fills the cavity, during which the pressure continues to increase.

[0050] The pressure holding phase lasts 30-150 seconds, with the pressure maintained at 700-950 mbar. This phase involves dimensional compensation and cooling of the cavity.

[0051] Depressurization phase: 30-60s, during which the wheel hub solidifies and depressurization occurs.

[0052] After the mold cavity is filled, immediately open the inner rim annular cooling water channel 14, the outer rim annular water cooler 16, and the spoke center annular cooling water channel 15 for 50-200 seconds at a water flow rate of 100-600 L / hr. In the latter half of the pressure holding stage, open the wheel center annular cooling water channel 17 for 20-100 seconds.

[0053] By controlling the cooling time and flow rate, the molten aluminum in the cavity crystallizes according to the cooling sequence of the mold. The crystallization starts from the middle of the outer rim 23, inner rim 22, and spokes 20 and proceeds in other directions until the center of the rim 19 and the center 21 finally crystallize.

Claims

1. Multi-gate aluminum alloy wheel casting mold, comprising a top die plate, a top die, a flow divider, a plurality of side dies, a plurality of gate discs, a bottom die and a bottom die plate, the flow divider is arranged on the top die, the top die is connected with the top die plate, the gate disc and the bottom die are arranged on the bottom die plate, and the side die is arranged between the top die plate and the bottom die plate; the center gate cup matched with the center gate is arranged at the center of the bottom die plate, the side gate cup matched with the side gate is arranged on the gate disc, the upper end of the gate cup is respectively communicated with the center gate and the side gate, and the lower end of the gate cup is communicated with the riser pipe inserted into the holding furnace; the top die, the flow divider, the side die, the gate disc and the bottom die are combined to form a casting blank cavity of the hub, and the blank cavity comprises a plurality of side gate forming cavities, a rim forming cavity, a spoke forming cavity and a hub forming cavity; the top die is provided with an annular cooling water channel corresponding to the inner rim position, and the bottom die is provided with annular cooling water channels corresponding to the middle of the spoke, the outer rim and the hub, characterized in that: The center gate size is set to ψ 50-65 mm, and the edge gate is ψ 50-70 mm; The edge gate is a horn-shaped gate that diverges from the rim, with the lower edge of the gate located 20-50 mm above the upper end of the outer rim and the upper edge located near the lower end of the inner rim, with a span of 50-150 mm and a cross-sectional thickness of 20-40 mm; The top die annular water channel has a diameter of 8-30 mm and is 10-40 mm away from the surface of the cavity, with a water flow of 100-600 L / hr; The bottom die outer rim annular water channel has a diameter of 8-30 mm and is 10-40 mm away from the surface of the cavity, with a water flow of 100-600 L / hr; The bottom die hub annular water channel has a diameter of 8-20 mm and is 20-40 mm away from the surface of the cavity, with a water flow of 100-400 L / hr.

2. A multi-gate aluminum alloy wheel casting method using the multi-gate aluminum alloy wheel casting mold of claim 1, characterized in that: The liquid lifting stage is 6-8 s, with the pressure rising from 0 to 180-200 mbar, and the aluminum liquid is lifted to the upper end of the liquid lifting pipe through multiple liquid lifting pipes; The first filling stage is 8-10 s, with the pressure rising from 180-200 mbar to 220-250 mbar, and the aluminum liquid fills the bottom of the spoke through multiple edge gates and a center gate; The second filling stage is 8-10 s, with the pressure rising from 220-250 mbar to 280-340 mbar, and the aluminum liquid slowly fills the spoke and the rim; The pressure increasing stage is 8-12 s, with the pressure rising from 280-340 mbar to 700-950 mbar, and this stage is the pressure increasing stage after the aluminum liquid fills the cavity; The pressure maintaining stage is 30-150 s, with the pressure maintained at 700-950 mbar, and this stage is the size shrinkage and cooling stage of the cavity; The pressure relief stage is 30-60 s, during which the hub solidifies and the pressure is released; After the cavity is filled, the inner rim annular cooling water channel, the outer rim annular water cooling, and the spoke middle annular cooling water channel are immediately opened, with a duration of 50-200 s and a water flow of 100-600 L / hr, and the hub annular cooling water channel is opened in the second half of the pressure maintaining stage, with a duration of 20-100 s.

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