A casting mold for a wheel hub with gate pressure and a casting method thereof

Abstract

The present invention belongs to the technical field of casting molds, and specifically is a gate pressurized wheel hub casting mold and a casting method thereof, the casting mold comprising a workbench, a mold and a pressurizing mechanism; a mold is installed at the center position of the workbench, the mold comprises a No. 1 mold, a No. 2 mold, a No. 3 mold and a No. 4 mold, the No. 1 mold is located at the top of the mold, the No. 2 mold and the No. 3 mold are located in the middle of the mold, and the No. 4 mold is located at the bottom of the mold; through the cooperation between the mold and the pressurizing mechanism, the pressurizing mechanism squeezes the molten metal through the runner, so that the flow speed of the molten metal into the cavity through the runner is increased, thereby increasing the shrinkage compensation effect of the molten metal on the wheel hub during cooling, thereby improving the casting quality of the wheel hub, and avoiding the reduction of the shrinkage compensation effect of the molten metal on the wheel hub during the cooling process of the wheel hub, resulting in more shrinkage holes or shrinkage in the wheel hub.

Description

Technical Field

[0001] The invention belongs to the technical field of casting molds, in particular to a gate pressurized hub casting mold and a casting method thereof. Background Art

[0002] A casting mold is a material that is made of other easily moldable materials in advance to obtain the structural shape of a part. The mold is then placed in a sand mold, so that a cavity with the same size as the part is formed in the sand mold. A fluid liquid is poured into the cavity, and after the liquid cools and solidifies, a part with the same shape and structure as the mold can be formed. Casting molds are used to match the casting process, and mainly include gravity casting molds, high-pressure casting molds, low-pressure casting molds, extrusion casting molds, etc. Casting molds are one of the most important process equipment in casting production, and have a great impact on the quality of castings.

[0003] In the prior art, when using a gravity casting mold to cast an aluminum alloy wheel hub, after the molten metal is poured into the mold, during the process of the molten metal changing from liquid to solid, it shrinks in the mold cavity due to the influence of the thermal expansion and contraction of the metal. If the molten metal is not replenished in time and effectively, when the molten metal solidifies in the mold cavity, due to the large offset value of the wheel hub, a wider solidification area is formed, and the molten metal solidifies in the solidification area in a volumetric solidification manner; in the late stage of solidification, the solid phase ratio is large, and the dendrites grow to form a skeleton, dividing the unsolidified molten metal into isolated Or nearly isolated small molten pools, these molten metals are difficult to be fed when solidified, and the cooling speed of various parts of the mold is the same, causing the molten metal in the runner to flow to the outer ring of the hub first, resulting in blockage at the gate position. When the hub center is cooled and needs to be fed, the molten metal is blocked and the feeding effect on the hub is reduced, thus forming many small and scattered holes, which will cause shrinkage cavities or shrinkage inside the hub and make the casting scrapped, thereby affecting the casting quality of the aluminum alloy wheel hub, and then increasing the casting cost of the aluminum alloy wheel hub.

[0004] In view of this, the present invention proposes a gate pressurized hub casting mold and a casting method thereof, which solve the above problems. Summary of the invention

[0005] In order to make up for the shortcomings of the prior art and solve the problem that when using a gravity casting mold to cast an aluminum alloy wheel hub, the metal liquid is blocked, the shrinkage compensation effect of the wheel hub is reduced, and many small and scattered holes are formed, which will cause shrinkage holes or shrinkage inside the wheel hub and make the casting scrapped, the present invention proposes a gate pressurized wheel hub casting mold and a casting method thereof.

[0006] The technical solution adopted by the present invention to solve the technical problem is as follows: a gate pressurized wheel hub casting mold described in the present invention includes a workbench, a mold and a pressurizing mechanism; a mold is installed at the center of the workbench, and the mold includes a No. 1 mold, a No. 2 mold, a No. 3 mold and a No. 4 mold, the No. 1 mold is located at the top of the mold, the No. 2 mold and the No. 3 mold are located in the middle of the mold, and the No. 4 mold is located at the bottom of the mold; the wall thicknesses of the No. 1 mold, the No. 2 mold, the No. 3 mold and the No. 4 mold are all set differently; a group of runners are evenly opened at the top of the No. 1 mold corresponding to the cavity in the No. 1 mold;

[0007] A pressurizing mechanism is installed on the workbench at a position away from the mold, and the pressurizing mechanism squeezes the molten metal through the runner.

[0008] When in use, before casting the aluminum alloy wheel hub, the mold is first heated to the temperature required for casting. The staff sprays a demoulding agent on the inner surfaces of the No. 1 mold, the No. 2 mold, the No. 3 mold and the No. 4 mold to make it easy to take the wheel hub out of the mold after casting. The staff closes the No. 1 mold, the No. 2 mold, the No. 3 mold and the No. 4 mold to form a casting cavity required for wheel hub casting inside the closed mold. The staff seals the mold joints to prevent leakage from the joints between the molds after pouring the molten metal; the staff discharges the molten metal into the mold through one of the runners until the molten metal overflows from the cavity into the runner, so that the molten metal inside each runner is greater than half of the runner; by setting the wall thickness of the No. 1 mold, the No. 2 mold, the No. 3 mold and the No. 4 mold to be different, the cooling speed of each part of the mold is different, which increases the shrinkage of the wheel hub through the runner when the molten metal is cooled. The effect is to reduce the gradual reserve amount of the hub, reduce the casting cost of the hub, and prevent the cooling speed of various parts of the mold from being the same, causing the molten metal in the runner to flow to the outer ring of the hub first, resulting in blockage at the gate position. When the hub center needs to be compensated after cooling, the molten metal is affected by the blockage and the shrinkage compensation effect on the hub center is reduced, resulting in shrinkage or shrinkage holes in the hub, reducing the casting quality of the hub; through the cooperation between the mold and the pressurizing mechanism, the pressurizing mechanism squeezes the molten metal through the runner, so that the flow speed of the molten metal through the runner into the cavity increases, thereby increasing the shrinkage compensation effect of the molten metal on the hub during cooling, thereby improving the casting quality of the hub, and avoiding the reduction of the shrinkage compensation effect of the molten metal on the hub during the cooling process, resulting in more shrinkage holes or shrinkage in the hub; after the mold is cooled, the mold is removed and the staff will carry out subsequent processing on the cast hub.

[0009] Preferably, the wall thickness of the No. 1 mold is greater than the wall thickness of the No. 2 mold and the No. 3 mold, and the wall thickness of the No. 4 mold is less than the wall thickness of the No. 2 mold and the No. 3 mold.

[0010] When in use, by setting the wall thickness of the No. 1 mold to be greater than the wall thickness of the No. 2 mold and the No. 3 mold, and the wall thickness of the No. 4 mold to be less than the wall thickness of the No. 2 mold and the No. 3 mold, after the staff discharges the molten metal into the mold through the runner, the flange located at the center of the hub is cooled first, and the molten metal in the runner flows into the cavity to compensate for the flange position at the center of the hub, followed by the spokes being cooled, the molten metal in the runner flows into the cavity to compensate for the spoke position, and then the rim is cooled, the molten metal in the runner passes through the cavity to compensate for the rim position, and finally the residual molten metal after the compensation in the runner is cooled, so that the hub is gradually compensated from long to short according to the flow distance of the molten metal, thereby increasing the compensation effect of the hub during casting, thereby reducing the gradual reserved amount of the hub, and further improving the quality of the hub after casting, avoiding the reduction of the compensation effect of the molten metal on the hub during the cooling process of the hub, resulting in more shrinkage holes or shrinkage in the hub.

[0011] Preferably, the runner cross section is trapezoidal.

[0012] When in use, by setting the runner cross-section to be trapezoidal, and the opening size of the runner toward the inside of the mold is smaller than the opening size of the runner toward the outside of the mold, after the staff discharges the molten metal into the mold through the runner, the pressurizing mechanism moves toward the inside of the runner, and the pressurizing mechanism squeezes the molten metal inside the runner. After being squeezed, the molten metal flows from the end of the runner with a smaller opening to the cavity in the mold. The flow space of the molten metal is squeezed by the runner, so that the flow velocity of the molten metal through the end of the runner with a smaller opening is increased, thereby increasing the movement speed of the molten metal to the cavity, and then increasing the movement speed of the molten metal to the cooling part of the hub for shrinkage compensation, thereby increasing the casting efficiency of the hub.

[0013] Preferably, a group of grooves are evenly formed at the bottom of the first mold near the pouring channel; and sliders are slidably connected in the grooves;

[0014] The top of the slider is located above the half position of the runner.

[0015] During use, the groove and the slider are matched and sealed to prevent the metal liquid from leaking between the groove and the slider; when the staff closes the mold, the slider is squeezed by the No. 3 mold and the No. 4 mold and slides into the groove until the slider seals the groove; after the wheel hub is cooled, the staff first removes the No. 2 mold and the No. 3 mold, and then lifts the No. 1 mold off the workbench. The wheel hub falls due to gravity, and the metal block formed by the cooling of the residual metal liquid in the runner is driven by the wheel hub to move away from the No. 1 mold. The metal block formed by the cooling of the residual metal liquid in the runner drives the slider to move away from the No. 1 mold, and the slider will not slide out of the groove until the metal block formed by the cooling of the residual metal liquid in the runner is separated from the runner, thereby separating the wheel hub from the No. 1 mold, so that the wheel hub is separated from the mold during the removal process. Separation increases the convenience of the wheel hub being separated from the mold after casting, and avoids the metal blocks formed by the cooling of the residual molten metal in the runner when the wheel hub is separated from the mold, which causes the wheel hub to be affected by the metal blocks formed by the cooling of the residual molten metal in the runner. The staff needs to manually separate the wheel hub and the mold, which reduces the convenience of the wheel hub being separated from the mold after casting and increases the labor intensity of the staff; by setting the top of the slider to be located above the half position of the runner, during the removal of the No. 1 mold, the slider is affected by the metal blocks formed by the cooling of the residual molten metal in the runner and slides out of the groove, and the residual molten metal in the runner is used to compensate for the shrinkage of the wheel hub, and the volume of the metal block formed by the cooling of the residual molten metal in the runner is smaller than the slider, so that when the slider slides out of the groove, the metal block formed by the cooling of the residual molten metal in the runner slides out of the runner accordingly, which increases the convenience of the wheel hub being separated from the mold after casting.

[0016] Preferably, the pressurizing mechanism comprises a hydraulic press and a controller, wherein the controller is used to control the hydraulic press; the workbench is fixedly connected with a fixed rod at a position away from the mold, the fixed rod is fixedly connected with a hydraulic press corresponding to the mold position, the output end of the hydraulic press is fixedly connected with a support rod, a group of extrusion rods are evenly installed on the outer surface of the support rod near the bottom position, and the extrusion rods are fixedly connected with a No. 1 rod at the position corresponding to the runner;

[0017] The pressurizing mechanism also includes a slide groove, and the position of the support rod corresponding to the extrusion rod is provided with the slide groove, one end of the extrusion rod close to the support rod is sleeved in the slide groove, the extrusion rod is slidably connected to the slide groove, and the extrusion rod and the slide groove are connected by a reset spring.

[0018] During use, when the pressure mechanism squeezes the molten metal through the runner, the staff controls the torque output by the hydraulic press through the controller, and by setting the No. 1 rod, when the pressure mechanism squeezes the molten metal through the runner, the hydraulic press drives the support rod to move, the support rod drives the extrusion rod to move, and the extrusion rod drives the No. 1 rod to move toward the inside of the runner until one end of the No. 1 rod extends into the runner and contacts the molten metal. The No. 1 rod squeezes the molten metal, increasing the flow rate of the molten metal through the runner into the cavity, thereby increasing the shrinkage compensation effect of the molten metal on the wheel hub during cooling, thereby improving the casting quality of the wheel hub, and avoiding the reduction of the shrinkage compensation effect of the molten metal on the wheel hub during the cooling process, resulting in more shrinkage holes or Shrinkage and loosening; by setting the slide groove, the hydraulic press drives the support rod to move, the support rod drives the extrusion rod to move, and the extrusion rod drives the No. 1 rod to move until it contacts the molten metal in the runner. When the shrinkage compensation amount of the hub part in the cavity is sufficient, the flow speed of the molten metal in the runner with sufficient shrinkage compensation amount of the corresponding hub slows down or even stops, and the No. 1 rod is affected by the slow-flowing or stopped molten metal, so that the No. 1 rod moves along the slide groove toward the hydraulic press, and the return spring is squeezed by the No. 1 rod to shrink, thereby increasing the protection of the pressurizing mechanism to the mold, thereby increasing the casting efficiency of the wheel hub and preventing the pressurizing mechanism from squeezing the molten metal too much, resulting in gaps at the joints between the molds, causing molten metal to leak and affecting the normal operation of the mold.

[0019] Preferably, a group of sealing rings are fixedly connected to the outer surface of the No. 1 rod, and the sealing rings are made of ceramic fiber packing.

[0020] When in use, a sealing ring is provided, and the sealing ring is made of ceramic fiber packing material. The ceramic fiber packing sealing ring in the present invention is woven from high-quality ceramic fibers. The maximum use temperature is 1260°C, while the casting temperature of the aluminum alloy wheel hub is 600°C-710°C. It has the advantages of resistance to corrosion by non-ferrous molten metals such as aluminum and zinc, light weight, high temperature resistance, small heat capacity, good thermal insulation performance, and good high-temperature insulation performance. The hydraulic press drives the support rod to move, the support rod drives the extrusion rod to move, the extrusion rod drives the No. 1 rod to move, and the No. 1 rod drives the sealing ring to move until one end of the No. 1 rod extends into the runner, and the part of the No. 1 rod away from the sealing ring is close to the inner wall of the runner, and the No. 1 rod drives the sealing ring to enter the runner and contact the inner wall of the runner. The cooperation between the sealing ring and the No. 1 rod seals the runner, increases the speed of the No. 1 rod extruding and pushing the molten metal to flow into the cavity, thereby increasing the casting efficiency of the wheel hub, and preventing the molten metal from seeping out of the runner to the outside of the mold after being squeezed, resulting in a decrease in the flow speed of the molten metal into the cavity, thereby affecting the casting efficiency of the wheel hub.

[0021] Preferably, the sealing ring is made of graphite packing.

[0022] When in use, the sealing sleeve is set to be made of graphite packing material. The graphite packing sealing ring in the present invention is mainly made of reinforced graphite wire as raw material and is carefully woven; the maximum working temperature of the graphite packing sealing ring is 1650°C, and its characteristic is that it is more suitable for dynamic sealing under high temperature and high pressure conditions; the sealing ring increases the sealing of the pouring channel during the process of extruding the molten metal through the pouring channel, thereby increasing the flow speed of the molten metal into the mold cavity driven by the No. 1 rod, thereby increasing the casting efficiency of the wheel hub, preventing the molten metal from seeping out of the mold from the pouring channel after being squeezed, resulting in a decrease in the flow speed of the molten metal into the mold cavity, thereby affecting the casting efficiency of the wheel hub.

[0023] A method for casting a gate pressurized wheel hub, which is applicable to the gate pressurized wheel hub described above, and comprises the following steps:

[0024] S1: Before casting the aluminum alloy wheel hub, the mold is first heated to the required casting temperature. The staff sprays a demoulding agent on the inner surface of the No. 1 mold, the No. 2 mold, the No. 3 mold and the No. 4 mold to facilitate the removal of the wheel hub from the mold after casting. The staff then closes the No. 1 mold, the No. 2 mold, the No. 3 mold and the No. 4 mold;

[0025] S2: After the mold is closed, a casting cavity required for wheel hub casting is formed inside the mold, and the staff seals the mold joints; the staff discharges the molten metal into the mold through one of the runners until the molten metal overflows from the cavity into the runner, so that the molten metal inside each runner is larger than half of the runner;

[0026] S3: The controller controls the pressurizing mechanism to extrude the molten metal. First, the flange at the center of the hub is cooled, followed by the spokes, then the rim, and finally the residual molten metal in the runner after shrinkage compensation. After the mold is cooled, the mold is removed and the staff will perform subsequent processing on the cast hub.

[0027] The beneficial effects of the present invention are as follows:

[0028] 1. The present invention discloses a gate pressurized wheel hub casting mold and a casting method thereof. By setting the wall thicknesses of the first mold, the second mold, the third mold and the fourth mold to be different, the cooling speeds of various parts of the mold are different, thereby increasing the effect of the molten metal on the shrinkage of the wheel hub through the runner during cooling, reducing the gradual reserve amount of the wheel hub, reducing the casting cost of the wheel hub, and preventing the cooling speeds of various parts of the mold from being the same, causing the molten metal in the runner to flow to the outer ring of the wheel hub first, resulting in blockage after the shrinkage compensation at the gate position is completed.

[0029] 2. The present invention describes a gate pressurized wheel hub casting mold and a casting method thereof. Through the cooperation between the mold and the pressurizing mechanism, the pressurizing mechanism squeezes the molten metal through the runner, so that the flow speed of the molten metal into the mold cavity through the runner is increased, thereby increasing the shrinkage compensation effect of the molten metal on the wheel hub during cooling, thereby improving the casting quality of the wheel hub and avoiding the reduction of the shrinkage compensation effect of the molten metal on the wheel hub during the cooling process, resulting in more shrinkage holes or shrinkage in the wheel hub. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the accompanying drawings.

[0031] Figure 1 is a flow chart of the casting method of the present invention;

[0032] Figure 2 is a three-dimensional diagram of a casting mold in the present invention;

[0033] Figure 3 It is a structural schematic diagram of a casting mold in the present invention;

[0034] Figure 4 It is another structural schematic diagram of the casting mold in the present invention;

[0035] Figure 5 yes Figure 3 A partial enlarged view of the middle A;

[0036] In the figure: workbench 1, mold 2, mold No. 1 21, mold No. 2 22, mold No. 3 23, mold No. 4 24, runner 25, groove 26, slider 27, pressurizing mechanism 3, hydraulic press 31, fixing rod 32, supporting rod 33, extrusion rod 34, rod No. 1 35, slide groove 36, sealing ring 37. DETAILED DESCRIPTION

[0037] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0038] like Figures 1 to 5 As shown;

[0039] Embodiment 1;

[0040] A gate pressurized wheel hub casting mold, comprising a workbench 1, a mold 2 and a pressurizing mechanism 3; a mold 2 is installed at the center of the workbench 1, and the mold 2 comprises a first mold 21, a second mold 22, a third mold 23 and a fourth mold 24, wherein the first mold 21 is located at the top of the mold 2, the second mold 22 and the third mold 23 are located in the middle of the mold 2, and the fourth mold 24 is located at the bottom of the mold 2; the wall thicknesses of the first mold 21, the second mold 22, the third mold 23 and the fourth mold 24 are all set differently; a group of runners 25 are evenly opened at the top of the first mold 21 corresponding to the cavity in the first mold 21;

[0041] A pressurizing mechanism 3 is installed on the workbench 1 at a position away from the mold 2 , and the pressurizing mechanism 3 extrude the molten metal through the runner 25 .

[0042] When in use, before casting the aluminum alloy wheel hub, the mold 2 is first heated to the temperature required for casting, and the staff sprays a demoulding agent on the inner surfaces of the No. 1 mold 21, the No. 2 mold 22, the No. 3 mold 23 and the No. 4 mold 24, so that the wheel hub can be easily taken out of the mold 2 after casting. The staff molds the No. 1 mold 21, the No. 2 mold 22, the No. 3 mold 23 and the No. 4 mold 24 together, and the casting cavity required for wheel hub casting is formed inside the mold 2 after the mold is molded together. The staff seals the connection of the mold 2 to prevent leakage from the connection between the molds 2 after pouring the molten metal; the staff discharges the molten metal into the mold 2 through one of the runners 25 until the molten metal overflows from the cavity into the runner 25, so that the molten metal inside each runner 25 is greater than half of the runner 25; by setting the wall thicknesses of the No. 1 mold 21, the No. 2 mold 22, the No. 3 mold 23 and the No. 4 mold 24 to be different, the cooling speed of each part of the mold 2 is different, and the metal molten metal is increased during cooling. The effect of the liquid on the shrinkage of the hub through the runner 25 is reduced, the gradual reserve amount of the hub is reduced, the casting cost of the hub is reduced, and the cooling speed of each part of the mold 2 is prevented from being the same, resulting in the metal liquid in the runner 25 flowing to the outer ring of the hub first, causing the shrinkage compensation at the gate position to be blocked. When the center of the hub needs to be compensated after cooling, the metal liquid is affected by the blockage and the shrinkage compensation effect on the center of the hub is reduced, thereby causing shrinkage or shrinkage holes in the hub, reducing the casting quality of the hub; through the cooperation between the mold 2 and the pressurizing mechanism 3, the pressurizing mechanism 3 squeezes the metal liquid through the runner 25, so that the flow speed of the metal liquid into the cavity through the runner 25 is increased, thereby increasing the shrinkage compensation effect of the metal liquid on the hub when cooling, thereby improving the casting quality of the hub, and avoiding the reduction of the shrinkage compensation effect of the metal liquid on the hub during the cooling process, resulting in more shrinkage holes or shrinkage in the hub; after the mold 2 is cooled, the mold 2 is removed, and the staff performs subsequent processing on the cast hub.

[0043] The wall thickness of the No. 1 mold 21 is greater than that of the No. 2 mold 22 and the No. 3 mold 23 , and the wall thickness of the No. 4 mold 24 is less than that of the No. 2 mold 22 and the No. 3 mold 23 .

[0044] When in use, by setting the wall thickness of the No. 1 mold 21 to be greater than the wall thickness of the No. 2 mold 22 and the No. 3 mold 23, and the wall thickness of the No. 4 mold 24 to be less than the wall thickness of the No. 2 mold 22 and the No. 3 mold 23, after the staff discharges the molten metal into the mold 2 through the runner 25, the flange at the center of the hub is cooled first, and the molten metal in the runner 25 flows into the cavity to compensate for the flange position at the center of the hub, followed by the spoke cooling, the molten metal in the runner 25 flows into the cavity to compensate for the spoke position, and then the rim is cooled, the molten metal in the runner 25 passes through the cavity to compensate for the rim position, and finally the residual molten metal after compensation in the runner 25 is cooled, so that the hub is gradually compensated from long to short according to the flow distance of the molten metal, thereby increasing the compensation effect of the hub during casting, thereby reducing the gradual reserve amount of the hub, and then improving the quality of the hub after casting, avoiding the reduction of the compensation effect of the molten metal on the hub during the cooling process, resulting in more shrinkage holes or shrinkage in the hub.

[0045] The cross section of the runner 25 is trapezoidal.

[0046] When in use, by setting the cross-section of the runner 25 to be trapezoidal, and the opening size of the runner 25 toward the inside of the mold 2 is smaller than the opening size of the runner 25 toward the outside of the mold 2, after the staff discharges the molten metal into the mold 2 through the runner 25, the pressurizing mechanism 3 moves toward the inside of the runner 25, and the pressurizing mechanism 3 squeezes the molten metal inside the runner 25. After being squeezed, the molten metal flows from the end of the runner 25 with a smaller opening to the cavity in the mold 2. The flow space of the molten metal is squeezed by the runner 25, so that the flow velocity of the molten metal through the end of the runner 25 with a smaller opening increases, thereby increasing the movement speed of the molten metal to the cavity, and then increasing the movement speed of the molten metal to the cooling part of the hub for shrinkage compensation, thereby increasing the casting efficiency of the hub.

[0047] A group of grooves 26 are evenly formed at the bottom of the first mold 21 near the pouring channel 25; sliders 27 are slidably connected in the grooves 26;

[0048] The top of the slider 27 is located above the half position of the runner 25 .

[0049] When in use, the groove 26 and the slider 27 are matched, and the groove 26 and the slider 27 are sealed to prevent the metal liquid from leaking from the groove 26 and the slider 27; when the staff closes the mold 2, the slider 27 is squeezed by the No. 3 mold 23 and the No. 4 mold 24 and slides into the groove 26 until the slider 27 seals the groove 26; after the wheel hub is cooled, the staff first removes the No. 2 mold 22 and the No. 3 mold 23, and then lifts the No. 1 mold 21 off the workbench 1, and the wheel hub falls due to the influence of gravity. The metal block formed by the cooling of the residual metal liquid in the runner 25 is driven by the wheel hub to move away from the No. 1 mold 21, and the metal block formed by the cooling of the residual metal liquid in the runner 25 drives the slider 27 to move away from the No. 1 mold 21, and the slider 27 will not slide out of the groove 26 until the metal block formed by the cooling of the residual metal liquid in the runner 25 is separated from the runner 25, thereby separating the wheel hub from the No. 1 mold 21, so that the mold 2 is removed during the removal process. The wheel hub is separated from the mold 2, which increases the convenience of the wheel hub being separated from the mold 2 after casting, and avoids the metal blocks formed by the cooling of the residual molten metal in the runner 25 when the wheel hub is separated from the mold 2. The metal blocks formed by the cooling of the residual molten metal in the runner 25 cause the wheel hub to be affected by the metal blocks formed by the cooling of the residual molten metal in the runner 25 when the wheel hub is separated from the mold 2, which requires the staff to manually separate the wheel hub and the mold 2, thereby reducing the convenience of the wheel hub being separated from the mold 2 after casting and increasing the labor intensity of the staff; by setting the top of the slider 27 to be located above the half position of the runner 25, during the removal of the No. 1 mold 21, the slider 27 is affected by the metal blocks formed by the cooling of the residual molten metal in the runner 25 and slides out of the groove 26, and the residual molten metal in the runner 25 is used to compensate for the shrinkage of the wheel hub, and the volume of the metal block formed by the cooling of the residual molten metal in the runner 25 is smaller than the slider 27, so that when the slider 27 slides out of the groove 26, the metal block formed by the cooling of the residual molten metal in the runner 25 slides out of the runner 25 accordingly, which increases the convenience of the wheel hub being separated from the mold 2 after casting.

[0050] The pressurizing mechanism 3 includes a hydraulic press 31 and a controller, and the controller is used to control the hydraulic press 31; the workbench 1 is fixedly connected to a fixed rod 32 at a position away from the mold 2, and the fixed rod 32 is fixedly connected to the hydraulic press 31 at a position corresponding to the mold 2, and the output end of the hydraulic press 31 is fixedly connected to a support rod 33, and a group of extrusion rods 34 are evenly installed on the outer surface of the support rod 33 near the bottom, and the extrusion rods 34 are fixedly connected to a No. 1 rod 35 at a position corresponding to the runner 25;

[0051] The pressurizing mechanism 3 also includes a slide groove 36, and the position of the support rod 33 corresponding to the extrusion rod 34 is provided with the slide groove 36, and one end of the extrusion rod 34 close to the support rod 33 is sleeved in the slide groove 36, and the extrusion rod 34 is slidably connected to the slide groove 36, and the extrusion rod 34 is connected to the slide groove 36 through a return spring.

[0052] During use, when the pressurizing mechanism 3 extrude the molten metal through the runner 25, the staff controls the torque output by the hydraulic press 31 through the controller, and by setting the No. 1 rod 35, when the pressurizing mechanism 3 extrude the molten metal through the runner 25, the hydraulic press 31 drives the support rod 33 to move, the support rod 33 drives the extrusion rod 34 to move, and the extrusion rod 34 drives the No. 1 rod 35 to move toward the inside of the runner 25 until one end of the No. 1 rod 35 extends into the runner 25 and contacts the molten metal. The No. 1 rod 35 extrude the molten metal, so that the flow speed of the molten metal through the runner 25 into the cavity is increased, thereby increasing the shrinkage compensation effect of the molten metal on the wheel hub during cooling, thereby improving the casting quality of the wheel hub, and avoiding the reduction of the shrinkage compensation effect of the molten metal on the wheel hub during the cooling process, resulting in more shrinkage holes or The shrinkage is loosened; by setting the slide groove 36, the hydraulic press 31 drives the support rod 33 to move, the support rod 33 drives the extrusion rod 34 to move, and the extrusion rod 34 drives the No. 1 rod 35 to move until it contacts the molten metal in the runner 25. When the shrinkage compensation amount of the hub part in the cavity is sufficient, the flow speed of the molten metal in the runner 25 with sufficient shrinkage compensation amount of the corresponding hub slows down or even stops, and the No. 1 rod 35 is affected by the slow-flowing or stopped molten metal, so that the No. 1 rod 35 moves along the slide groove 36 toward the hydraulic press 31, and the return spring is squeezed by the No. 1 rod 35 to shrink, thereby increasing the protection of the pressurizing mechanism 3 to the mold 2, thereby increasing the casting efficiency of the wheel hub, and preventing the pressurizing mechanism 3 from squeezing the molten metal too much, resulting in gaps at the connection between the molds 2, causing the molten metal to leak and affecting the normal operation of the mold 2.

[0053] A set of sealing rings 37 are fixedly connected to the outer surface of the No. 1 rod 35, and the sealing rings 37 are made of ceramic fiber packing.

[0054] When in use, by setting the sealing ring 37, and the sealing ring 37 is made of ceramic fiber packing, the ceramic fiber packing sealing ring 37 of the present invention is woven from high-quality ceramic fibers; the maximum use temperature is 1260°C, while the casting temperature of the aluminum alloy wheel hub is 600°C-710°C, and it has the advantages of resistance to corrosion by non-ferrous molten metals such as aluminum and zinc, light weight, high temperature resistance, small heat capacity, good thermal insulation performance, and good high-temperature insulation performance; the hydraulic press 31 drives the support rod 33 to move, the support rod 33 drives the extrusion rod 34 to move, the extrusion rod 34 drives the No. 1 rod 35 to move, and the No. The rod 35 drives the sealing ring 37 to move until one end of the No. 1 rod 35 extends into the runner 25, and the part of the No. 1 rod 35 away from the sealing ring 37 is close to the inner wall of the runner 25. The No. 1 rod 35 drives the sealing ring 37 to enter the runner 25 and contact the inner wall of the runner 25. The cooperation between the sealing ring 37 and the No. 1 rod 35 seals the runner 25, increases the speed of the No. 1 rod 35 squeezing and pushing the molten metal to flow into the cavity, thereby increasing the casting efficiency of the wheel hub, and preventing the molten metal from seeping out of the runner 25 to the outside of the mold 2 after being squeezed, resulting in a decrease in the flow speed of the molten metal into the cavity, thereby affecting the casting efficiency of the wheel hub.

[0055] A method for casting a gate pressurized wheel hub, which is applicable to the gate pressurized wheel hub described above, and comprises the following steps:

[0056] S1: Before casting the aluminum alloy wheel hub, the mold 2 is first heated to the required casting temperature, and the staff sprays a demoulding agent on the inner surfaces of the first mold 21, the second mold 22, the third mold 23 and the fourth mold 24, so that the wheel hub can be easily removed from the mold 2 after casting, and the staff closes the first mold 21, the second mold 22, the third mold 23 and the fourth mold 24;

[0057] S2: After the mold is closed, a casting cavity required for wheel hub casting is formed inside the mold 2, and the staff seals the joint of the mold 2; the staff discharges the molten metal into the mold 2 through one of the runners 25 until the molten metal overflows from the cavity into the runner 25, so that the molten metal inside each runner 25 is larger than half of the runner 25;

[0058] S3: The controller controls the pressurizing mechanism 3 to extrude the molten metal. First, the flange at the center of the hub is cooled, followed by the spokes, then the rim, and finally the residual molten metal in the runner 25 after shrinkage compensation is cooled. After the mold 2 is cooled, the mold 2 is removed, and the staff performs subsequent processing on the cast hub.

[0059] Embodiment 2:

[0060] The difference between the second embodiment and the first embodiment is that;

[0061] The sealing ring is made of graphite packing;

[0062] By setting the sealing sleeve to be made of graphite packing material, the graphite packing sealing ring 37 in the present invention is mainly made of reinforced graphite wire as raw material and is finely woven; the maximum working temperature of the graphite packing sealing ring 37 is 1650°C, and its characteristic is that it is more suitable for dynamic sealing under high temperature and high pressure conditions; the sealing ring 37 increases the sealing performance of the runner 25 during the process of extruding the molten metal through the runner 25, thereby increasing the flow speed of the molten metal into the mold cavity pushed by the No. 1 rod 35, thereby increasing the casting efficiency of the wheel hub, and preventing the molten metal from leaking from the runner 25 to the outside of the mold 2 after being squeezed, resulting in a decrease in the flow speed of the molten metal into the mold cavity, thereby affecting the casting efficiency of the wheel hub.

[0063] The specific workflow is as follows:

[0064] Before casting the aluminum alloy wheel hub, the mold 2 is first heated to the temperature required for casting, and the staff sprays a demoulding agent on the inner surfaces of the No. 1 mold 21, the No. 2 mold 22, the No. 3 mold 23 and the No. 4 mold 24. The staff closes the molds 21, the No. 2 mold 22, the No. 3 mold 23 and the No. 4 mold 24, and the casting cavity required for wheel hub casting is formed inside the mold 2 after closing. The staff seals the connection of the mold 2; the staff discharges the molten metal into the mold 2 through one of the runners 25 until the molten metal overflows from the cavity into the runner 25, so that the molten metal inside each runner 25 is larger than half of the runner 25; the pressurizing mechanism 3 The molten metal is squeezed through the runner 25; first, the flange at the center of the hub is cooled, and the molten metal in the runner 25 flows into the cavity to feed the flange at the center of the hub, and then the spoke is cooled, and the molten metal in the runner 25 flows into the cavity to feed the spoke, and then the rim is cooled, and the molten metal in the runner 25 passes through the cavity to feed the rim, and finally the residual molten metal in the runner 25 after feeding is cooled, so that the hub is gradually fed from long to short according to the flow distance of the molten metal; after the mold 2 is cooled, the mold 2 is removed, and the staff performs subsequent processing on the cast hub.

[0065] In order to verify the practical application effect of the present invention, the following experiments were conducted:

[0066] 1. Experimental Design

[0067] A group of aluminum alloy wheels cast by a gravity casting mold of the prior art was taken as a control group, and a group of aluminum alloy wheels cast by a gate pressure casting mold of the present application was taken as an experimental group;

[0068] X-ray flaw detection technology was used to detect the control group and the experimental group, and the severity of the discontinuity detected by X-ray was graded according to the Chinese national standard GB / T11346;

[0069] 2. Sample Preparation

[0070] A group of aluminum alloy wheels cast by different gravity casting molds in the prior art was taken as a control group, and a group of aluminum alloy wheels cast by the gate pressure casting mold of the present application was taken as an experimental group;

[0071] The experimental group and the control group were sent to the aluminum alloy casting testing center and tested using the UNT series X-ray real-time imaging testing equipment produced by Unilink Technology;

[0072] 3. Test results

[0073] Experimental Group:

[0074] Table 1

[0075]

[0076] Table 1 shows the detection levels obtained by sending the experimental group to the aluminum alloy casting inspection center and using the UNT series X-ray real-time imaging inspection equipment produced by Rilian Technology. When the penetration thickness is 1 / 4 inch, the detection severity levels of pores, shrinkage cavities and shrinkage porosity of the aluminum alloy wheel hub cast by the gate pressure casting mold of this application are all level 2, while the detection severity levels of round pinholes and long pinholes are all level 3; when the penetration thickness is 3 / 4 inch, the detection severity levels of pores, shrinkage cavities and shrinkage porosity of the aluminum alloy wheel hub cast by the gate pressure casting mold of this application are all level 2, the long pinholes are level 4, and the round pinholes are level 3.

[0077] Control group:

[0078] Table 2

[0079]

[0080] Table 2 shows the detection levels obtained by sending the control group to the aluminum alloy casting inspection center and using the UNT series X-ray real-time imaging detection equipment produced by Rilian Technology. When the penetration thickness is 1 / 4 inch, the air holes and long pinholes of the aluminum alloy wheel hub cast by the gravity casting mold of the prior art are both level 5, the shrinkage holes are level 3, the shrinkage is level 4, and the circular pinholes are level 7; when the penetration thickness is 3 / 4 inch, the air holes and long pinholes of the aluminum alloy wheel hub cast by the gravity casting mold of the prior art are both level 5, the shrinkage holes and shrinkage are both level 4, and the circular pinholes are level 7.

[0081] Combined with the above experimental data, the summary is as follows:

[0082] By comparing Table 1 and Table 2 above, by making the cooling speeds of various parts of the mold different and cooperating with the pressure mechanism, the pressure mechanism squeezes the molten metal through the runner, so that the flow speed of the molten metal into the cavity through the runner is increased, thereby significantly improving the shrinkage compensation effect of the molten metal on the wheel hub during cooling; when the transillumination thickness is 1 / 4 inch, the detection severity levels of the pores, shrinkage cavities and shrinkage porosity of the aluminum alloy wheel hub cast by the gate pressure casting mold of the present application are all level 2, and the detection severity levels of the circular pinholes and the elongated pinholes are all level 3, while the pores and elongated pinholes of the aluminum alloy wheel hub cast by the gravity casting mold of the prior art are all level 5, the shrinkage cavities are level 3, the shrinkage porosity is level 4, and the circular pinholes are level 7; When the thickness of the transillumination is 3 / 4 inch, the severity levels of the air holes, shrinkage holes and shrinkage porosity of the aluminum alloy wheel hub cast by the gate pressure casting mold of the present application are all level 2, the elongated pinholes are level 4, and the circular pinholes are level 3. The air holes and elongated pinholes of the aluminum alloy wheel hub cast by the gravity casting mold of the prior art are both level 5, the shrinkage holes and shrinkage porosity are both level 4, and the circular pinholes are level 7. The lower the severity level in the Chinese national standard GB / T11346, the fewer defects and the higher the quality of the workpiece detected. It can be seen that the aluminum alloy wheel hub cast by the gate pressure casting mold of the present application is better than the aluminum alloy wheel hub cast by the gravity casting mold of the prior art. Therefore, the present invention has a broader market prospect in the field of automotive aluminum alloy wheels.

[0083] The above-mentioned front, back, left, right, top and bottom are all based on the figures in the specification. Figure 2 As a benchmark, according to the person's observation perspective, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0084] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0085] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A gate pressurized wheel hub casting mold, comprising a workbench (1), a mold (2) and a pressurizing mechanism (3); characterized in that: A mold (2) is installed at the center of the workbench (1), and the mold (2) includes a first mold (21), a second mold (22), a third mold (23) and a fourth mold (24), wherein the first mold (21) is located at the top of the mold (2), the second mold (22) and the third mold (23) are located in the middle of the mold (2), and the fourth mold (24) is located at the bottom of the mold (2); the wall thicknesses of the first mold (21), the second mold (22), the third mold (23) and the fourth mold (24) are all set differently; a group of runners (25) are evenly opened at the top of the first mold (21) corresponding to the mold cavity in the first mold (21); a pressurizing mechanism (3) is installed at a position on the workbench (1) away from the mold (2), and the pressurizing mechanism (3) extrude the molten metal through the runner (25); The wall thickness of the first mold (21) is greater than that of the second mold (22) and the third mold (23), and the wall thickness of the fourth mold (24) is less than that of the second mold (22) and the third mold (23); by setting the wall thicknesses of the first mold (21), the second mold (22), the third mold (23) and the fourth mold (24) to be different, the cooling speeds of various parts of the mold (2) are different, thereby increasing the effect of the molten metal on the hub through the runner (25) during cooling; first, the flange at the center of the hub is cooled, and the molten metal in the runner (25) flows into the cavity to the flange position at the center of the hub for shrinkage compensation, then the spokes are cooled, and the molten metal in the runner (25) flows into the cavity to the spoke position for shrinkage compensation, then the rim is cooled, and the molten metal in the runner (25) passes through the cavity to the rim position for shrinkage compensation, and finally, the residual molten metal in the runner (25) after shrinkage compensation is cooled; The cross section of the pouring channel (25) is trapezoidal; A group of grooves (26) are evenly formed at the bottom of the first mold (21) near the pouring channel (25); and sliders (27) are slidably connected in the grooves (26); The top of the slider (27) is located above the half position of the pouring channel (25); The pressurizing mechanism (3) comprises a hydraulic press (31) and a controller, wherein the controller is used to control the hydraulic press (31); a fixing rod (32) is fixedly connected to a position of the workbench (1) away from the mold (2); the fixing rod (32) is fixedly connected to the hydraulic press (31) at a position corresponding to the mold (2); a support rod (33) is fixedly connected to the output end of the hydraulic press (31); a group of extrusion rods (34) are evenly installed on the outer surface of the support rod (33) near the bottom; and the extrusion rods (34) are fixedly connected to a No. 1 rod (35) at a position corresponding to the pouring channel (25); The pressurizing mechanism (3) further comprises a slide groove (36), the slide groove (36) is provided at a position of the support rod (33) corresponding to the extrusion rod (34), one end of the extrusion rod (34) close to the support rod (33) is sleeved in the slide groove (36), the extrusion rod (34) is slidably connected to the slide groove (36), and the extrusion rod (34) and the slide groove (36) are connected via a return spring; A group of sealing rings (37) are fixedly connected to the outer surface of the No. 1 rod (35), and the sealing rings (37) are made of ceramic fiber packing.

2. A gate pressurized wheel hub casting method, characterized in that: The method is applicable to the gate pressurized hub casting mold according to claim 1, and the method comprises the following steps: S1: Before casting the aluminum alloy wheel hub, the mold (2) is first heated to a temperature required for casting, and a worker sprays a demoulding agent on the inner surfaces of the first mold (21), the second mold (22), the third mold (23) and the fourth mold (24) so ​​that the wheel hub can be easily removed from the mold (2) after casting, and the worker closes the first mold (21), the second mold (22), the third mold (23) and the fourth mold (24); S2: After the mold is closed, a casting cavity required for wheel hub casting is formed inside the mold (2), and the staff seals the joint of the mold (2); the staff discharges the molten metal into the mold (2) through one of the runners (25) until the molten metal overflows from the cavity into the runner (25), so that the molten metal inside each runner (25) is larger than half of the runner (25); S3: The controller controls the pressurizing mechanism (3) to extrude the molten metal. First, the flange at the center of the hub is cooled, then the spokes are cooled, then the rim is cooled, and finally the residual molten metal in the runner (25) after shrinkage compensation is cooled. After the mold (2) is cooled, the mold (2) is removed, and the staff performs subsequent processing on the cast hub.

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