Casting system and mold for concatemer shell

Abstract

The invention relates to the field of metal mold casting, in particular to a multi-conjoined shell pouring system and a mold, the pouring system comprises a horizontal runner, at least one straight runner arranged below the horizontal runner and at least two vertical runners arranged above the horizontal runner, the vertical runners are mutually independent, and the vertical runners are mutually independent. The axis of the vertical cross gate is concentric with the center of a casting bottom flange and leads to a casting inner cavity, the casting bottom flange inner cavity is provided with a bottom flange ingate, the bottom flange ingate is communicated with the vertical cross gate, the end flange cross gate is cylindrical, the axis of the end flange cross gate coincides with the axis of a barrel, one end of the end flange cross gate is communicated with the vertical cross gate, and the other end of the end flange cross gate exceeds the flange end face. A plurality of end flange ingates are arranged in inner cavities of the flanges at the two ends of the casting barrel and communicated with the end flange cross gates. The pouring system ensures that a molten aluminum mold filling temperature field is uniform and solidification feeding is good, and the inherent quality of produced castings is good. The mould is prevented from being scalded; and in the mold closing and pouring processes, the problem that the sand sleeve slides out to cause the casting to be lack of meat is avoided.

Description

Technical Field

[0001] This invention relates to the field of metal mold casting, and more specifically to a multi-shell gating system and mold. Background Technology

[0002] Multi-unit housings, as a common type of complex aluminum alloy casting housing for high-voltage electrical applications, often feature multiple sets of mutually perpendicular flanged support cylinders on the main cylinder, resembling several simple housings combined together. When using any flange face of a mutually perpendicular flanged support cylinder perpendicular to the main cylinder axis as the mold parting surface, the back of the other flange cannot be directly demolded. In low-pressure casting using a metal mold, the non-demolding portion requires a movable block. Due to the large number and weight of these movable blocks during production, and their high temperature, installation is difficult. Therefore, multi-unit housings are typically produced using a horizontally placed sand casting process. However, sand casting suffers from complex mold design, high difficulty, long production time, and difficulty in ensuring the coating quality of flanges that cannot be directly demolded. This results in poor dimensional accuracy and appearance quality of the final product, low production efficiency, and high production costs. Furthermore, sand casting produces castings with inferior mechanical properties compared to metal mold casting.

[0003] Aluminum alloy casting shells are widely produced using low-pressure metal mold casting. In the production of multi-unit shells using metal mold casting, besides the difficulty in demolding the back of the flange on one side of the casting, the design of the gating system is also crucial to ensuring good casting quality. While existing technology includes three-unit metal molds, these molds lack a casting gating system, failing to guarantee uniform temperature distribution during aluminum molten metal filling and proper solidification and feeding. Furthermore, the installation of the flange sand core may result in burns; and during mold closing and pouring, the sand sleeve may slip out, causing incomplete casting. Summary of the Invention

[0004] This invention provides a multi-shell casting system and mold. The casting system ensures a uniform temperature field during aluminum molten metal filling and good solidification and feeding, resulting in high-quality castings. The mold avoids scalding issues; and during mold closing and casting, it prevents sand sleeve slippage that could cause incomplete casting.

[0005] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, a multi-unit shell casting system includes: A horizontal runner, at least one sprue located below the horizontal runner, and at least two vertical runners located above the horizontal runner. The vertical runners are independent of each other, and their axes are concentric with the center of the bottom flange of the casting, leading to the inner cavity of the casting. The inner cavity of the bottom flange of the casting is provided with a bottom flange ingate, which is connected to the vertical runners.

[0006] The end flange has a horizontal runner, which is cylindrical in shape. The axis of the end flange horizontal runner coincides with the axis of the casting cylinder. One end is connected to the vertical horizontal runner, and the other end extends beyond the flange end face. Several end flange inner runners are provided in the inner cavity of the flanges at both ends of the casting cylinder. The end flange inner runners are connected to the end flange horizontal runner.

[0007] This gating system ensures uniform aluminum molten metal filling temperature and good solidification feeding during the casting process of the multi-unit shell, resulting in high-quality castings, improved yield, and easier core making and cleaning. Utilizing metal mold casting technology, the castings exhibit excellent appearance quality, high dimensional accuracy, significantly reduced production costs, and significantly improved production efficiency. The number of riser pipes required is small, and existing equipment can be used directly.

[0008] In some possible embodiments, it also includes: The side flange horizontal runner is cylindrical, with its axis coinciding with the axis of the side flange support cylinder of the casting. One end is connected to the vertical horizontal runner, and the other end extends beyond the flange end face. The inner cavity of the casting side flange is provided with two side flange horizontal inlets, which are connected to the side flange horizontal runner.

[0009] The side flange has a vertical inner runner. One end of the vertical inner runner is connected to the side flange horizontal runner, and the other end is connected to the inner wall of the side flange support sleeve to ensure the support sleeve shrinkage.

[0010] The side flange has an inclined inlet runner, with one end connected to the horizontal runner at the center of the side flange, and the other end inclined to the side flange axis and connected to the inner wall of the side flange support. The runner extends obliquely upwards from the center of the side flange, reducing the scouring of the aluminum melt on the sand sleeve and providing better feeding at the top of the side flange support where it contacts the sand sleeve.

[0011] In some possible embodiments, it also includes: Several rectangular inlet gates are connected to several vertical and horizontal runners, which are responsible for filling the mold during the pouring process above the rectangular blocks on the other side of the side flange, ensuring better forming of the other side of the casting side flange. At the same time, during the solidification process, they also play a role in feeding the rectangular blocks.

[0012] A concealed riser is placed on the end face of the top flange of the casting. While ensuring the quality of the top flange, it also provides feeding through the riser and facilitates cleaning.

[0013] In some possible embodiments, the sprue has a frustum-shaped structure with a draft angle from top to bottom. The sprue is located at 1 / 2 ± 100 mm between two adjacent vertical and horizontal sprues, ensuring uniform aluminum temperature during the filling process of multiple vertical and horizontal sprues into multiple parts of the casting, and uniform feeding effect during solidification. When the number of sprues is greater than or equal to 2, the distance between two adjacent sprues is equal to the distance between adjacent riser pipes in the low-pressure casting holding furnace, which facilitates the filling of aluminum liquid into multiple sprues by multiple riser pipes.

[0014] In some possible embodiments, a bottom flange cross runner is provided in the center of the bottom flange inner runner, which is connected to the vertical and horizontal runners to fill the lower part of the casting and to compensate for the shrinkage of multiple bottom flanges; an end flange cross runner is provided in the center of the end flange inner runner, which is connected to the end flange horizontal runner to fill the upper part of the casting and to compensate for the shrinkage of the end flanges.

[0015] Secondly, a multi-unit shell casting mold includes a bottom mold, a left mold, a right mold, at least two sand sleeves, a sand core, and at least two insulating riser sleeves; The left mold and the right mold are located on both sides of the bottom film. At least two sand sleeves are located in at least two sand sleeve positioning grooves of the left mold or the right mold, and at least two heat insulation risers are located in the heat insulation riser sleeve grooves of the left mold or the right mold. The cavity formed by the bottom mold, left mold, right mold, at least two sand sleeves, sand cores and at least two insulating riser sleeves is the cavity of a multi-unit shell casting with the above-mentioned gating system; The cavity of the left or right mold, along with the inner surface and end face of the sand sleeve and half of the inner surface of the insulating riser sleeve, serves as the mold cavity for one side of the casting's side flange. The cavity of the right or left mold and the other half of the inner surface of the insulating riser sleeve serve as the mold cavity for the other side of the casting's side flange. Based on this gating system and mold structure, a uniform temperature field for aluminum liquid filling and good solidification feeding can be ensured, resulting in high-quality castings.

[0016] In some possible embodiments, the bottom mold has a groove at its center that matches the bottom core head of the sand core; the groove has at least one sprue at its center, which has a truncated cone cavity structure with a draft angle from top to bottom to facilitate the removal of the casting sprue; the sprue and the sprue are perfectly matched; a retaining structure is provided around the bottom mold groove, with a draft angle on the outside of the retaining structure in the mold opening direction, which better facilitates mold closing and positioning and further prevents aluminum liquid from overflowing.

[0017] In some possible embodiments, the sand jacket includes a main body component and a positioning component; The main component is a ring, with one end being a ring surface and the outer surface being a cylindrical surface. The inner surface matches the shape of the outer surface of the flange back cylinder that cannot be directly demolded from the casting. The outer surface and the inner surface intersect at the edge. The positioning component is positioned in the same direction as the axial direction of the main component. One end is located on the upper side of the ring, and the other end extends beyond the main component, matching the shape of the upper outer side of the casting cylinder. The positioning components include a vertical positioning component and a horizontal positioning component. One end of the vertical positioning component is located on the upper side of the annular body, and the other end extends beyond the main body component, matching the shape of the upper outer side of the casting cylinder. When the sand sleeve is matched with the casting, the vertical positioning component extends from one end of the annular body to the surface of the casting cylinder and the mold parting surface, which is beneficial for the side flange inclined sprue to compensate for the shrinkage of the cylinder on both sides of the positioning component and for the venting of the top of the casting, resulting in better casting quality. The horizontal positioning component is located on the vertical positioning component and extends to the mold parting surface.

[0018] The sand sleeve structure is easy to install. By setting positioning components, the sand sleeve can be placed into the matching position on the mold parting surface and slid to the corresponding position to achieve installation. There is no need to enter the mold cavity to place the sand sleeve, avoiding high temperature burns.

[0019] In some possible embodiments, at least two positioning components of the sand sleeve are installed in the positioning groove of the sand sleeve in the left or right mold, with a fitting clearance. The outer surface of the main body component of the sand sleeve body matches the cylindrical receiving groove of the side flange of the left or right mold, with a fitting clearance. The left or right mold has a limiting step facing outward at the flange back position corresponding to the casting, for further limiting the main body component as a whole on the flange back. After the mold is closed, the parting surface of the other half of the mold limits the sand sleeve, preventing the sand sleeve from shifting during mold closing or pouring, thus avoiding missing material in the poured blank casting.

[0020] On both sides of the parting surface of the left and right molds, the end face of the top flange cavity has a left mold insulation riser sleeve groove and a right mold insulation riser sleeve groove, respectively. The left mold insulation riser sleeve groove and the right mold insulation riser sleeve groove are mirror images of each other, forming a semi-cylindrical or frustum-conical cavity. One end of the cavity is closed, and the other end is a riser neck cavity with a diameter that first decreases and then remains constant, smaller than the outer diameter of the cavity by one insulation riser sleeve wall thickness. This cavity communicates with the top flange cavity of the left and right molds. The left and right mold insulation riser sleeve grooves work in conjunction with the insulation riser sleeves to provide aluminum molten material feeding during the solidification process of the top flange.

[0021] In some possible embodiments, the sand core has a cavity matching the horizontal runner and the upper runner of the gating system; the bottom of the sand core has a large cuboid core head, the bottom surface of which is on the same plane as the bottom surface of the horizontal runner. The length of the large core head is not less than the farthest distance between the inner diameters of the two farthest bottom flanges, and the width is not less than the inner diameter of the bottom flange. The cuboid core head has a draft angle from top to bottom, and the height of the large core head is greater than or equal to 50mm of the height of the horizontal runner. The closest distance between the top surface of the large core head and the inner runner hole of the bottom flange is not less than 30mm. The bottom mold rapidly cools the bottom surface of the horizontal runner during the filling process, which has no significant impact on filling and shrinkage compensation. At the same time, it facilitates the removal of the horizontal runner model during core making and accelerates the solidification of the runner during the pouring process, thus improving the production pace. The bottom core head adopts a large core head form, wherein the bottom runner of the sand core is an open, straight horizontal runner, which facilitates core making and brushing while ensuring shrinkage compensation. The gating system above the horizontal runner is an independent system, which improves the yield and facilitates core making and cleaning.

[0022] The two ends of the sand core are cylindrical, with a diameter equal to the diameter of the inner flanges at both ends of the casting system. A plug is provided on the outer side of the cavity of the sand core corresponding to the horizontal runner of the end flange. The plug is used at this position to seal the aluminum liquid inside the sand core, prevent the mold from rapidly cooling the horizontal runner of the end flange, reduce the feeding capacity of the horizontal runner of the end flange, and prevent the core head from being covered with aluminum.

[0023] The side flange core head of the sand core has a frustum structure. The diameter of the large circle end face of the frustum is the inner diameter of the side flange of the casting system. It has a draft angle. A plug is provided on the outside of the cavity of the sand core corresponding to the side flange sprue. The plug seals the molten aluminum inside the sand core. The plug is used at this position to seal the molten aluminum inside the sand core, prevent the mold from rapidly cooling the side flange sprue, reduce the feeding capacity of the side flange sprue, and prevent the core head from being covered with aluminum.

[0024] From the top surface of the top flange sand core head to the flange face of the top flange, remove a portion of the outer diameter of the top sand core head from both sides inward along the length of the sand core to leave sufficient thickness for the left and right molds. For the two planes perpendicular to the top surface of the core head, start demolding from the parting surface to facilitate the sand core top core head to be molded with the left and right molds.

[0025] The side flange has an upward-sloping runner from the center, reducing the scouring of the molten aluminum on the sand sleeve and better compensating for the top of the side flange support cylinder in contact with the sand sleeve. Simultaneously, in conjunction with the sand sleeve positioning components, it enhances the compensating effect of the molten aluminum on the top of the metal mold cavity. The downward-sloping ingate is a vertical ingate located at a certain distance from the flange cavity, facilitating core making, removal of the sprue bar, and compensating for the shrinkage between the two support cylinders in contact with the sand sleeve. Attached Figure Description

[0026] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of a triplet shell blank according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a three-piece shell metal mold low-pressure casting process gating system according to an embodiment of the present invention; Figure 3 This is a cross-sectional schematic diagram of a three-part metal mold low-pressure casting process gating system according to an embodiment of the present invention, which is divided by the vertical parting surface of the middle flange of the three flanges. Figure 4 This is a cross-sectional schematic diagram of a three-part metal mold low-pressure casting process gating system according to an embodiment of the present invention, which is divided by the vertical parting surface of the right flange of the three flanges. Figure 5 This is a schematic diagram of the bottom mold of a three-piece shell metal mold for low-pressure casting process according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the left mold before installing the sand sleeve in a three-piece metal mold low-pressure casting process mold according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the left mold after installing the sand sleeve in a three-piece metal mold low-pressure casting process mold according to an embodiment of the present invention; Figure 8 This is a cross-sectional view of a three-piece shell metal mold low-pressure casting process mold according to an embodiment of the present invention, which is divided by the parting surface; Figure 9 This is a cross-sectional view of a three-piece metal mold low-pressure casting process mold according to an embodiment of the present invention, which is divided by the vertical parting surface of the middle flange of the three flanges. Figure 10 This is a cross-sectional view of a three-part metal mold low-pressure casting process mold according to an embodiment of the present invention, which is divided by the vertical parting surface of the right flange of the three flanges; Figure 11 This is a first-angle schematic diagram of the sand sleeve structure in a low-pressure casting process for a three-piece metal mold according to an embodiment of the present invention. Figure 12 This is a second-angle schematic diagram of the sand sleeve structure in a low-pressure casting process for a three-piece metal mold according to an embodiment of the present invention; Figure 13 This is a schematic diagram of the main core structure of a three-piece shell metal mold low-pressure casting process according to an embodiment of the present invention; Figure 14 This is a schematic diagram illustrating the matching of a three-piece metal mold low-pressure casting casting with a sand core and sand sleeve according to an embodiment of the present invention. Wherein: A - Tri-shell blank; 1 - Tri-shell gating system; 101 - Straight runner; 102 - Horizontal runner; 103 - Vertical runner; 104 - Bottom flange ingate; 105 - End flange runner; 106 - End flange ingate; 107 - Side flange runner; 108 - Side flange horizontal ingate; 109 - Side flange vertical ingate; 110 - Side flange oblique ingate; 111 - Rectangular ingate. 112-Hidden riser, 2-Bottom mold, 21-Straight gate, 22-Groove, 23-Blocking structure, 3-Left mold, 301-Sand sleeve positioning groove, 302-Side flange cylindrical receiving groove, 303-Left mold insulation riser sleeve groove, 304-Limiting step, 4-Right mold, 401-Right mold insulation riser sleeve groove, 5-Sand sleeve, 501-Main component, 502-Positioning component, 6-Sand core, 61-First plug, 62-Second plug, 7-Insulation riser sleeve. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0028] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this invention is for describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0029] This embodiment uses a triplet shell as an example, such as Figure 1 The schematic diagram of the triple-shell blank A shows a cylindrical body with inner flanges at both ends. The cylindrical body has three pairs of mutually perpendicular flanged support structures. A sheet-like auxiliary structure connects two pairs of mutually perpendicular support structures. The three side flanges face upwards at approximately 45° and each has a cuboid structure. At the top of the cylindrical body between the two left-side flanges, there is a support structure with a top flange. When the top flange is removed, the surface perpendicular to the center of the middle flange of the triple-shell blank is used as a mirror image; the triple-shell blank is mirror-symmetrical. It is evident that this structure is complex. When any flange surface perpendicular to the mutually perpendicular flanged support structure of the cylindrical body and passing through the axis of the main casting is used as the mold parting surface, the back part of the other flange cannot be directly demolded.

[0030] In sand casting, for flange locations where direct demolding is not possible, flange movable blocks are added to the basic mold, or parting lines are created and sand cores are fabricated. This results in a large number of movable blocks, multiple parting surfaces, and complex mold design. Sand mold shaping is complex, difficult, and time-consuming. The painting quality of flanges that cannot be directly demolded is difficult to guarantee, leading to poor dimensional accuracy and appearance quality in the final product, and low production efficiency. Furthermore, each cast blank uses one sand mold and one sand core, resulting in high production costs. Compared to metal mold casting, sand casting also produces castings with inferior mechanical properties.

[0031] The existing three-piece metal mold includes a bottom template, a left template, a right template, a main sand core, and a flange sand core. The main sand core is assembled on the upper surface of the bottom template, and the left and right templates are assembled on the left and right sides of the upper surface of the bottom template. The structure of the bottom template, left template, and right template is designed to facilitate mold closing and opening. The flange sand core is designed and installed in the left template, allowing the flange to be formed directly by casting. Compared with sand molds, this reduces the number of parting surfaces and mold plates, as well as the number of movable parts, thereby improving production efficiency, appearance quality, and dimensional accuracy, while reducing production costs.

[0032] However, this mold lacks a gating system, failing to guarantee uniform temperature distribution during aluminum molten metal filling and proper solidification and feeding. The sand sleeve, aside from its outer circumference, lacks additional positioning structures, potentially causing burns when manually inserted into the cavity. Furthermore, the absence of an anti-slip structure means the sand sleeve may slip out during mold closing and pouring, resulting in incomplete casting. Its three cores are individual cores, and the three bottom flanges are located in the bottom mold, with a movable block structure between each pair of flanges. With this structure, if a vertical and horizontal sprue cavity is placed between the three sand cores, and the three sprues in the bottom mold are connected to this cavity, and the riser pipes are connected to the sprues, then pre-production preparation requires the preparation and installation of three riser pipes. The low-pressure casting furnace must have a furnace cover capable of housing three riser pipes, with the distance between each pair approximately equal to the distance between the centers of the two vertical and horizontal sprues. Double riser pipe furnace covers are commonly used in low-pressure casting. Depending on the requirements, single and double riser pipes may be used. For low-pressure casting furnaces with three riser pipes and a fixed distance between the two pipes, a dedicated furnace cover is needed, and the furnace body also requires a larger size.

[0033] The bottom flange uses a movable block structure between each pair of flanges to facilitate the removal of the casting from the bottom mold. However, the movable block is heavy and at high temperature, making on-site operation difficult.

[0034] Based on this, such as Figure 2As shown, this embodiment of the invention provides a three-piece shell gating system 1 using a metal mold low-pressure casting process, including a horizontal runner 102, two sprues 101 located below the horizontal runner 102, and three vertical runners 103 located above the horizontal runner 102. The three vertical runners 103 are independent of each other, and the axis of the vertical runners 103 is concentric with the center of the bottom flange of the casting and leads to the inner cavity of the casting. The inner cavity of the bottom flange of the casting is provided with a bottom flange ingate 104, which is connected to the vertical runners 103. The triple shell gating system 1 also includes an end flange horizontal runner 105, which is cylindrical. The axis of the end flange horizontal runner 105 coincides with the axis of the casting cylinder. One end is connected to the vertical horizontal runner 103, and the other end extends beyond the flange end face. Several end flange inner runners 106 are provided in the inner cavity of the flanges at both ends of the casting cylinder. The end flange inner runners 106 are connected to the end flange horizontal runner 105.

[0035] A horizontal runner 102 is connected above the sprue 101. The horizontal runner 102 has a cuboid structure and a draft angle from top to bottom of no more than -1°. This runner is fabricated on the bottom surface of the large core head of the sand core 6, facilitating the demolding of the runner pattern. In this embodiment, the bottom core head adopts a large core head form, which facilitates the implementation of the gating system. The horizontal runner 102 at the bottom of the sand core is an open, straight horizontal runner, which facilitates core making and brushing while ensuring shrinkage compensation. The triple-unit housing of this embodiment can be applied to high-voltage electrical housings as well as other fields.

[0036] Above the horizontal runner 102, three cylindrical vertical runners 103 are evenly distributed. The axes of the three vertical runners 103 are concentric with the centers of the three bottom flanges of the casting and lead to the inner cavity of the casting. The three-piece casting has inner flanges at both ends of the cylinder. One end of the end flange runner 105 is connected to the vertical runners 103, and the other end extends beyond the flange end face by not less than 20mm.

[0037] A double-sprue horizontal runner 102 is used, which in turn connects to three vertical runners 103. These runners are then connected to the three cylinders of the triplet casting via a bottom flange inner sprue 104, or further connected to the casting via a branch inner sprue from the vertical runners 103. This gating system ensures a uniform temperature field for the molten aluminum filling and good solidification and feeding, resulting in high-quality castings. The gating system above the horizontal runner 102 is an independent system, improving yield and facilitating core making and cleaning.

[0038] Compared to the existing triplet castings which are generally produced using sand casting and low-pressure casting, the metal mold casting process produces triplet castings with better appearance quality, higher dimensional accuracy, significantly reduced production costs, and significantly improved production efficiency.

[0039] In some embodiments, such as Figure 3 , 4As shown, the triple shell gating system 1 also includes: The side flange horizontal runner 107 is cylindrical, with its axis coinciding with the axis of the casting side flange support cylinder. One end is connected to the vertical horizontal runner 103, and the other end extends beyond the flange end face. The inner cavity of the casting side flange is provided with two side flange horizontal inlets 108, which are connected to the side flange horizontal runner 107.

[0040] The vertical inner runner 109 of the side flange is connected at one end to the horizontal runner 107 of the side flange, and at the other end to the inner wall of the side flange support sleeve.

[0041] The side flange has an inclined inlet 110, one end of which is connected to the side flange horizontal runner 107 at the center of the side flange, and the other end is inclined at a certain angle to the side flange axis, which can be 45°, and is connected to the inner wall of the side flange support cylinder for filling and feeding the top surface of the support cylinder. The three side flanges have inclined inlet runners from the center of the flange upwards, which reduces the scouring of the aluminum liquid on the sand sleeve 5 and better feeds the top position of the side flange support cylinder in contact with the sand sleeve.

[0042] The triplet casting has three side flanges on its cylindrical body, and a cylindrical horizontal runner 107 is provided for each side flange. The axis of the horizontal runner 107 coincides with the axis of the side flange support cylinder. One end of the horizontal runner 103 is connected to the vertical horizontal runner 103, and the other end extends beyond the flange end face by no less than 20mm. The inner cavities of the three casting side flanges each have two horizontal ingates 108 connected to the horizontal runners 107 for filling and ensuring the side flanges compensate for shrinkage. The vertical ingate 109 is connected at one end to the horizontal runners 107 and at the other end to the inner wall of the side flange support cylinder to ensure the support cylinder compensates for shrinkage. The support cylinder is provided here to increase strength.

[0043] In some embodiments, such as Figure 3 , 4 As shown, the triple shell gating system 1 also includes: Three rectangular ingates 111 are connected to three vertical and horizontal runners 103, respectively, for filling the casting mold and feeding the three cuboid positions. Since the three vertical and horizontal runners 103 are independent of each other, the yield is improved, and sand core molding and casting cleaning are facilitated.

[0044] A concealed riser 112 is located on the end face of the top flange of the casting. The top flange uses two concealed risers 112 for feeding, which ensures the quality of the top flange while facilitating cleaning.

[0045] In some embodiments, the sprue 101 has a frustum-shaped structure with a draft angle of not less than 2° from top to bottom, facilitating removal from the bottom mold. The two sprues 101 are approximately located at the halfway point between each pair of the three vertical and horizontal sprues, specifically within a range of 1 / 2 ± 100 mm, ensuring uniform aluminum temperature during the filling process of the three parts of the casting by the three vertical and horizontal sprues 103, and consistent feeding effect during solidification. For the two sprues 101, the distance between two adjacent sprues 101 is equal to the distance between adjacent riser pipes in the low-pressure casting holding furnace, facilitating the filling of aluminum liquid into the two sprues 101 by the double riser pipes.

[0046] In some embodiments, a bottom flange ingate 104 has a central cross runner that communicates with the vertical and horizontal runners 103; an end flange ingate 106 has a central cross runner that communicates with the end flange horizontal runner 105. The cross runner can be a cross-shaped bar, and each of the three bottom flange cavities has a cross-shaped bar-shaped bottom flange ingate 104 that communicates with the vertical and horizontal runners 103, for filling the lower part of the casting and feeding the multiple bottom flanges. The flange cavities at both ends of the casting cylinder each have a cross-shaped bar-shaped end flange ingate 106 that communicates with the end flange horizontal runner 105, for filling the upper part of the casting and feeding the end flanges.

[0047] like Figure 5 , 6 As shown in 7, 8, 9, and 10, this embodiment also provides a multi-unit shell casting mold, including a bottom mold 2, a left mold 3, a right mold 4, a sand sleeve 5, a sand core 6, and an insulating riser sleeve 7.

[0048] Left mold 3 and right mold 4 are located on both sides of bottom mold 2. Sand sleeve 5 is located in sand sleeve positioning groove 301 of left mold 3. Two heat insulation riser sleeves 7 are respectively located in left mold heat insulation riser sleeve groove 303 and right mold heat insulation riser sleeve groove 401 of left mold 3 or right mold 4. The cavity formed by the bottom mold 2, left mold 3, right mold 4, three sand sleeves 5, sand core 6, and two insulating riser sleeves 7 constitutes the casting cavity of the above-mentioned gating system. Furthermore, based on this gating system and mold structure, it is possible to ensure a uniform temperature field for aluminum liquid filling and good solidification and feeding, resulting in high-quality castings.

[0049] The cavity of the left mold 3, the inner surface and end face of the sand sleeve 5, and half of the inner surface of the insulating riser sleeve 7 serve as the mold cavity on one side of the casting side flange. The cavity of the right mold 4 and the other half of the inner surface of the insulating riser sleeve 7 serve as the mold cavity on the other side of the casting side flange.

[0050] In some embodiments, such as Figure 5As shown, the bottom mold has a groove 22 at its center, which can be a rectangular groove. The groove 22 matches the bottom core head of the sand core 6, with a clearance of no more than 0.5mm around the perimeter. Two sprues 21 are located at the center of the groove 22. The sprues 21 have a truncated cone cavity structure with a draft angle of no less than 2° from top to bottom, facilitating the removal of the sprue 101 from the casting. The sprues 21 and sprue 101 are perfectly matched. A retaining structure 23 is provided around the bottom mold groove 22, with a width of no less than 20mm and a height of no more than or equal to 20mm. The draft angle of the retaining structure 23 on the outside in the mold opening direction is no less than 3°. This structure improves mold closing positioning and further prevents molten aluminum from overflowing.

[0051] like Figure 11 , 12 As shown, the sand sleeve 5 includes a main body component 501 and a positioning component 502.

[0052] The main component 501 is a ring, with one end being a ring surface and the outer surface being a cylindrical surface. The inner surface matches the shape of the outer surface of the flange back cylinder that cannot be directly demolded from the casting. The outer surface and the inner surface intersect at the edge. The positioning component 502 is positioned in the same direction as the axial direction of the main component 501. One end is located on the upper side of the ring, and the other end extends beyond the main component 501, matching the shape of the upper outer side of the casting cylinder. The positioning component 502 includes a vertical positioning component and a horizontal positioning component. One end of the vertical positioning component is located on the upper side of the annular body, and the other end extends beyond the main component 501, matching the shape of the upper outer side of the casting cylinder. When the sand sleeve 5 is matched with the casting, the vertical positioning component extends from one end of the annular body to the surface of the casting cylinder and the mold parting surface, which is beneficial for the side flange inclined sprue to compensate for the shrinkage of the cylinder on both sides of the positioning component and for the venting of the top of the casting, resulting in better casting quality. The horizontal positioning component is located on the vertical positioning component and extends to the mold parting surface.

[0053] The sand sleeve 5 can be an integral structure. The end face of the main component 501 is a circular plane, which is used to form the back of the side flange during casting. The outer diameter is greater than or equal to the outer diameter of the side flange of the casting by 2mm, and the inner diameter is the same as the inner diameter of the back of the flange of the casting. The outer diameter of the main component 501 is greater than or equal to the outer diameter of the flange of the casting at that position by 2 mm, and the inner diameter is the same as the inner diameter of the flange back of the casting. The draft angle of the outer surface of the main component 501 is not greater than -1°, and terminates at the outer surface of the casting, forming an outer circumference portion, which facilitates the installation of the sand sleeve 5 at the side flange position. The outer surface is a conical structure, and the outer surface of the main component 501 intersects with the casting cylinder at the edge. The inner surface of the main component 501 is the outer surface of the casting cylinder surrounded by the conical structure surface.

[0054] The positioning component 502 can be a T-shaped structure, consisting of a vertical positioning component and a horizontal positioning component. One end of the T-shaped structure is on the same plane as the annular body. Alternatively, it may not be on the same plane as the end face of the annular body. The vertical positioning component is located at the position of maximum height on the outer wall of the annular body, with a width of not less than 40mm to ensure sufficient strength.

[0055] The vertical positioning component can be plate-shaped, i.e., a vertical plate, with its bottom shape matching the shape of the upper side of the annular body and the outer side of the casting cylinder, and its top shape matching the shape of the horizontal positioning component. The plate-shaped structure facilitates the insertion of the positioning component 502 from the parting surface. A portion of the vertical plate extends to the casting surface, forming the outer surface of the casting, while the remaining portion extends to the mold parting surface. The horizontal positioning component can also be plate-shaped, serving a suspension function; alternatively, it can be other shapes that provide a suspension effect. The end face length of the suspension plate should be no less than 70mm, and the height no less than 40mm to ensure sufficient strength. The minimum distance between the suspension plate and the casting should be no less than 20mm to allow sufficient thickness for the mold and not significantly affect its lifespan.

[0056] The suspension plate extends to the parting surface, facilitating the insertion of the T-shaped positioning component from the mold parting surface and acting as a limiter during the mold closing and pouring process, preventing it from slipping out. The T-shaped positioning component is perpendicular to the parting surface and stretches towards it, with a draft angle of no more than -1°, facilitating the installation of the sand sleeve 5 in the corresponding sand sleeve positioning groove 301 of the left mold 3, and allowing it to slide to the corresponding position on the left mold 3. Part of the vertical plate extends to the extended surface of the cavity of the left mold 3 to form the inner surface of the casting, while the remaining part extends to the parting surface of the left mold 3. The suspension portion extends to the parting surface, facilitating the insertion of the T-shaped positioning component from the parting surface and acting as a limiter during the mold closing and pouring process, preventing it from slipping out. The minimum distance between the sand sleeve 5 and the left mold cavity is no less than 20mm, providing sufficient thickness for the mold and not significantly affecting its lifespan. The sand sleeve 5 is positioned on the mold by the positioning component 502. By setting the positioning component 502, the sand sleeve 5 can be placed into the matching position on the mold parting surface and slid to the corresponding position to achieve installation. There is no need to enter the mold cavity to place the sand sleeve, thus avoiding high temperature burns.

[0057] In some embodiments, the positioning component 502 of the sand sleeve 5 is installed in the sand sleeve positioning groove 301 of the left mold, with a fitting clearance of less than or equal to 1 mm. The outer surface of the main component 501 matches the cylindrical surface of the side flange of the side flange cylindrical receiving groove 302 of the left mold 3, with a fitting clearance of less than or equal to 0.5 mm. The left mold has a limiting step 304 extending outward from the back of the flange corresponding to the casting; the left mold 3 has a limiting step 304 extending outward from the back of the flange, which is greater than or equal to 2 mm of the flange outer diameter. Figure 9 , 10As shown, the main component 501 is further restricted on the back of the flange. The sand sleeve 5 structure is easy to install. After the mold is closed, the other half of the mold parting surface is restricted by the sand sleeve, which will prevent the sand sleeve from shifting during mold closing or pouring, thus preventing the cast blank from having insufficient material.

[0058] On both sides of the parting surface of the left mold 3 and the right mold 4, the end face of the top flange cavity has a left mold insulation riser sleeve groove 303 and a right mold insulation riser sleeve groove 401, respectively. The left mold insulation riser sleeve groove 303 and the right mold insulation riser sleeve groove 401 are mirror images of each other, forming a semi-cylindrical or frustum-conical cavity. One end of the cavity is closed, and the other end is a riser neck cavity with a diameter that first decreases and then remains constant, less than the outer diameter of the cavity by one insulation riser sleeve wall thickness. Its height is no more than 15mm, and it communicates with the top flange cavities of the left mold 3 and the right mold 4. The left and right mold insulation riser sleeve grooves work in conjunction with the insulation riser sleeves to replenish the aluminum liquid during the solidification process of the top flange.

[0059] In some embodiments, such as Figure 13 , 14 As shown, sand core 6 is a monolithic sand core used to form the inner surface of the triple-shell gating system 1. Sand core 6 has a horizontal sprue 102 of the triple-shell gating system 1 and a matching gating system cavity above it. The bottom of sand core 6 has a large cuboid core head, the bottom surface of which is flush with the bottom surface of the horizontal sprue 102 of the casting 1 with the gating system. When sand core 6 is lowered into the mold, only the bottom surface of the horizontal sprue 102 cavity of sand core 6 contacts the mold. The bottom mold 2 rapidly cools the bottom surface of the horizontal sprue 102 during the filling process, having no significant impact on filling and shrinkage compensation. Simultaneously, it facilitates the removal of the horizontal sprue 102 model during core making and accelerates the solidification of the gating system during pouring, thus improving the production pace. The bottom core head adopts a large core head design, and the bottom sprue of the sand core is an open, straight horizontal sprue cavity, facilitating core making and brushing.

[0060] The length of the large core head shall not be less than the furthest distance between the inner diameters of the two farthest bottom flanges, and the width shall not be less than the inner diameter of the bottom flange. The draft angle of the cuboid core head from top to bottom shall not be less than 2°, and the height of the large core head shall not be less than 50mm above the height of the horizontal runner 102 of the triple shell gating system 1, ensuring that the bottom large core head of the sand core 6 has sufficient strength. The closest distance between the top surface of the large core head of the sand core 6 and the inner runner hole of the bottom flange shall not be less than 30mm, ensuring that the end faces of the bottom flanges of the left mold 3 and right mold 4 have sufficient thickness to ensure the cooling effect on the bottom flange. The two ends of the sand core 6 are cylindrical, with a diameter equal to the diameter of the inner flanges at both ends of the casting system, and a length of not less than 50 mm. A first plug 61 is installed on the outer side of the cavity of the sand core 6 corresponding to the horizontal runner 105 of the end flange. The first plug 61 is used at this position to seal the aluminum liquid inside the sand core 6, prevent the mold from rapidly cooling the horizontal runner 105 of the end flange, reduce the feeding capacity of the horizontal runner 105 of the end flange, and prevent the core head from being covered with aluminum. The end face of the cavity corresponding to the horizontal runner 105 of the end flange is sealed with the first plug 61. The length outside the flange end face is not less than 20 mm to ensure the sand mold thickness between the inner runner 105 of the end flange and the first plug 61, and to prevent breakage and sand loss.

[0061] The three side flange core heads of sand core 6 are frustum structures. The diameter of the large circle end face of the frustum is the inner diameter of the side flange of the casting system. The draft angle is not less than 5° to facilitate the closing of the left mold 3. The length is not less than 50mm. A second plug 62 is installed on the outer side of the cavity of sand core 6 corresponding to the side flange sprue 107. The second plug 62 is used at this position to seal the aluminum liquid inside sand core 6, prevent the mold from rapidly cooling the side flange sprue 107, reduce the feeding capacity of the side flange sprue 107, and prevent the core head from being covered with aluminum. The length is not less than 20mm outside the flange end face to ensure the sand mold thickness between the side flange sprue 107 and the second plug 62, and to prevent breakage and sand loss. The second plug 62 seals the aluminum liquid inside sand core 6, resulting in a slower temperature drop of the aluminum liquid and better filling and feeding effect. The height of the top core head of sand core 6 is not less than 30mm, and the diameter is the inner diameter of the top flange. From the top surface of the top flange sand core 6 to the flange face, remove 20mm from both sides of the outer diameter of the top core of sand core 6 along the length of the sand core to leave sufficient thickness for the left mold 3 and right mold 4 at this position. For the two planes perpendicular to the top surface of the core, start demolding from the parting surface, with a draft angle of not less than 5°, to facilitate the closing of the top core of sand core 6 with the left mold 3 and right mold 4.

[0062] The three side flanges have sprues that run upwards from the center of the flanges, reducing the scouring of the molten aluminum on the sand sleeve and better compensating for the top of the side flange support cylinders that are in contact with the sand sleeve. At the same time, in conjunction with the sand sleeve 5 positioning, they enhance the compensating effect of the molten aluminum on the top of the metal mold cavity. The downward ingate is a vertical ingate that runs at a certain distance from the flange cavity, which facilitates core making, removal of the sprue bar, and compensating for the two support cylinders that are in contact with the sand sleeve.

[0063] The insulation riser sleeve 7 is an asbestos insulation riser sleeve with a wall thickness of about 10mm and a height of not less than 120mm. It has a closed upper end and an open lower end, with a cylindrical or frustum-shaped cavity structure and an inner diameter of not less than 55mm.

[0064] Some embodiments employ a low-pressure metal mold casting process, and the production operation is as follows: 1. Open the left mold 3 and the right mold 4; 2. Lift the positioning parts 502 of the two sand sleeves 5 and insert the two sand sleeves 5 into the left mold 3; 3. Place the sand core 6 into the bottom mold 2; 4. Insert the two insulating riser sleeves 7 into the left mold 3 left mold insulating riser sleeve groove 303 or insert the insulating riser sleeve 7 into the right mold 4 right mold insulating riser sleeve groove 401; 5. Combine left mold 2 and right mold 3; 6. Pouring. Under pressure, the molten aluminum in the low-pressure casting furnace rises through the riser pipe and simultaneously enters the two sprue openings 21 of the bottom mold 2 (i.e., the cavities of the two sprue runners 101). The molten aluminum further rises into the horizontal runner 102 cavity formed by the groove 22 of the bottom mold 2 and the large core head of the sand core 6. After filling the horizontal runner 102 cavity of the sand core 6, the molten aluminum further rises into the three vertical runner 103 cavities of the sand core 6. When the molten aluminum rises to the height of the bottom flange inlet runner 104 cavity in the vertical runner 103 cavity, it begins to enter the bottom flange cavity and fill the casting cavities below the bottom flange and end flange runner 105. As the molten aluminum further rises in the three vertical runner 103 cavities of the sand core 6, it rises to the end flange runner 105. At height 05, molten aluminum from the vertical runners 103 at both ends enters the horizontal runner 105 of the end flange of the sand core 6, the horizontal runner 107 of the side flange, and the rectangular ingate 111. Molten aluminum from the vertical runner 103 in the middle enters the horizontal runner 107 of the side flange of the sand core 6 and the rectangular ingate 111. Molten aluminum from the horizontal runner 105 of the end flange of the sand core 6 then enters the ingate 106 of the end flange. Molten aluminum from the horizontal runner 107 of the side flange of the sand core 6 then enters the horizontal ingate 108 of the side flange, the vertical ingate 109 of the side flange, and the oblique ingate 110 of the side flange. Molten aluminum begins to fill the casting cavity above the horizontal runners of the end flange. As filling progresses, the molten aluminum rises until it fills the insulation riser sleeve, completing the casting filling process.

[0065] 7. Remove the casting system. Open the left mold 3 and the right mold 4; use slings to lift the two ends of the casting and pull out the casting with the sand core 6 and sand sleeve 5 containing the casting system.

[0066] The above processes can be directly used with existing equipment. Employing metal mold casting results in high-quality castings with excellent dimensional accuracy, significantly reduced production costs, and significantly improved production efficiency. Existing equipment can be used directly with these processes.

[0067] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or equivalent to the scope of this invention are included in this invention.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A multi-shell casting system, characterized in that: include: A horizontal runner, at least one sprue located below the horizontal runner, and at least two vertical runners located above the horizontal runner. The vertical runners are independent of each other, and their axes are concentric with the center of the bottom flange of the casting and lead to the inner cavity of the casting. The inner cavity of the bottom flange of the casting is provided with a bottom flange ingate, which is connected to the vertical runners. The end flange has a horizontal runner, which is cylindrical in shape. The axis of the end flange horizontal runner coincides with the axis of the casting cylinder. One end is connected to the vertical horizontal runner, and the other end extends beyond the flange end face. Several end flange inner runners are provided in the inner cavity of the flanges at both ends of the casting cylinder. The end flange inner runners are connected to the end flange horizontal runner.

2. The multi-shell casting system according to claim 1, characterized in that: Also includes: The side flange horizontal runner is cylindrical, with its axis coinciding with the axis of the side flange support cylinder of the casting. One end is connected to the vertical horizontal runner, and the other end extends beyond the flange end face. The inner cavity of the casting side flange is provided with two side flange horizontal inlets, which are connected to the side flange horizontal runner. The side flange has a vertical inner runner, one end of which is connected to the side flange horizontal runner, and the other end is connected to the inner wall of the side flange support sleeve. The oblique inner runner of the side flange has one end connected to the horizontal runner of the side flange at the center of the side flange, and the other end is at a certain angle to the axis of the side flange and connected to the inner wall of the side flange support cylinder.

3. The multi-shell casting system according to claim 1, characterized in that: Also includes: Several rectangular blocks have internal gating channels, and these internal gating channels are connected to several vertical and horizontal gating channels. A concealed riser is located on the top flange end face of the casting.

4. The multi-shell casting system according to claim 1, characterized in that: The sprue has a truncated cone structure with a draft angle from top to bottom. The sprue is located at 1 / 2 ± 100 mm between two adjacent vertical and horizontal sprues. When the number of sprues is greater than or equal to 2, the distance between two adjacent sprues is equal to the distance between adjacent riser pipes in the low-pressure casting holding furnace.

5. The multi-shell casting system according to claim 1, characterized in that: The bottom flange inner runner has a cross runner in the center, which is connected to the vertical and horizontal runners; the end flange inner runner has a cross runner in the center, which is connected to the horizontal runners.

6. A multi-unit shell casting mold, characterized in that: Includes bottom mold, left mold, right mold, at least two sand sleeves, sand core, and at least two insulating riser sleeves; The left mold and the right mold are located on both sides of the bottom film. At least two sand sleeves are located in at least two sand sleeve positioning grooves of the left mold or the right mold, and at least two heat insulation risers are located in the heat insulation riser sleeve grooves of the left mold or the right mold. The cavity formed by the bottom mold, left mold, right mold, at least two sand sleeves, sand cores and at least two insulating riser sleeves is a multi-unit shell casting cavity with the gating system described in any one of claims 1-5; The cavity of the left or right mold, along with the inner surface, end face, and half of the inner surface of the insulating riser sleeve, serves as the mold cavity on one side of the casting side flange. The cavity of the right or left mold and the other half of the inner surface of the insulating riser sleeve serve as the mold cavity on the other side of the casting side flange.

7. The multi-unit shell casting mold according to claim 6, characterized in that: The bottom mold has a groove in the center, which matches the bottom core head of the sand core; the groove has at least one sprue in the center, which has a truncated cone cavity structure and a draft angle from top to bottom; the sprue matches the sprue perfectly; the bottom mold groove is surrounded by a retaining structure, and the outer side of the retaining structure in the mold opening direction has a draft angle.

8. The multi-unit shell casting mold according to claim 6, characterized in that: The sand jacket includes a main body component and a positioning component; The main component is a ring, with one end being a ring surface and the outer surface being a cylindrical surface. The inner surface matches the shape of the outer surface of the flange back cylinder that cannot be directly demolded from the casting. The outer surface and the inner surface intersect at the edge. The positioning component is positioned in the same direction as the axial direction of the main component. One end is located on the upper side of the ring, and the other end extends beyond the main component, matching the shape of the upper outer side of the casting cylinder. The positioning components include a vertical positioning component and a horizontal positioning component. One end of the vertical positioning component is located on the upper side of the annular body, and the other end extends beyond the main body component, matching the shape of the upper outer side of the casting cylinder. When the sand sleeve is matched with the casting, the vertical positioning component extends from one end of the upper side of the annular body to the surface of the casting cylinder and the mold parting surface. The horizontal positioning component is located on the vertical positioning component and extends to the mold parting surface.

9. The multi-unit shell casting mold according to claim 8, characterized in that: At least two sand sleeve positioning components are installed in the sand sleeve positioning groove of the left mold or the right mold, with a fitting clearance. The outer surface of the main body component of the sand sleeve body matches the cylindrical receiving groove of the side flange of the left mold or the right mold, with a fitting clearance. The left mold or the right mold has a limiting step on the back of the flange corresponding to the casting. On both sides of the parting surface of the left and right molds, the end face of the top flange cavity has the left mold insulation riser sleeve groove and the right mold insulation riser sleeve groove, respectively; among them, the left mold insulation riser sleeve groove and the right mold insulation riser sleeve groove are mirror symmetrical, forming a semi-cylindrical or frustum-cone cavity. One end of the cavity is closed, and the other end is smaller than the outer diameter of the cavity by one insulation riser sleeve wall thickness. The riser neck cavity has a diameter that first decreases and then remains constant, and is connected to the top flange cavity of the left and right molds.

10. The multi-unit shell casting mold according to claim 6, characterized in that: The sand core has a cavity that matches the horizontal runner and the upper runner of the gating system; the bottom of the sand core has a cuboid core head, the bottom surface of the core head is on the same plane as the bottom surface of the horizontal runner, the length of the core head is not less than the farthest distance between the inner diameters of the two farthest bottom flanges, the width is not less than the inner diameter of the bottom flange, the cuboid core head has a draft angle from top to bottom, the height of the core head is greater than or equal to the height of the horizontal runner by 50mm, and the closest distance between the top surface of the sand core core and the inner runner hole of the bottom flange is not less than 30mm; The two ends of the sand core are cylindrical, with a diameter equal to the diameter of the inner flanges at both ends of the casting system. The end flanges have plugs on the outer side of the cavity of the sand core corresponding to the horizontal runner. The side flange core head of the sand core has a frustum structure. The diameter of the large circle end face of the frustum is the inner diameter of the side flange of the casting system. It has a draft angle. The side flange transverse runner is provided with a plug on the outside of the cavity of the sand core. The plug seals the aluminum liquid inside the sand core. From the top surface of the top flange sand core head to the flange face of the top flange, remove a portion of the outer diameter of the top core head from both sides inward along the length of the sand core to leave sufficient thickness for the left and right molds. For the two planes perpendicular to the top surface of the core head, start demolding from the parting surface.

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