Outer shell core and casting box

Abstract

The utility model belongs to the technical field of hub casting, and particularly relates to an outer wrapping shell core and a casting box, the outer wrapping shell core is used for forming an annular groove structure of a casting part, the casting part comprises a hub, the outer wrapping shell core comprises an axial connecting part, a first outer edge part and a second outer edge part, the axial connecting part is arranged around the casting part, and the first outer edge part is arranged around the hub. The axial connecting part is arranged at the upper end of the annular groove structure and used for forming the bottom face of the annular groove structure, the first outer edge part is arranged at the upper end of the axial connecting part and used for forming the upper side wall of the annular groove structure, and the second outer edge part is arranged at the lower end of the axial connecting part and used for forming the lower side wall of the annular groove structure. And the axial connecting part is recessed relative to the first outer edge part and the second outer edge part to form a weight reduction groove. The weight reducing groove can reduce the wall thickness of the outer wrapping shell core, the total amount of smoke and irritant gas generated by additives such as resin and a curing agent in the precoated sand at the high temperature is reduced, the risk that air holes are generated in the hub is reduced, and the yield of hub castings is increased.

Description

Technical Field

[0001] The present application belongs to the technical field of wheel hub casting, and specifically relates to an outer shell core and a casting box. Background Art

[0002] Ductile iron castings such as wheel hubs are important security parts for automobile chassis. They are usually made by casting blanks and then machining them. Common wheel hubs in the prior art are split from the flange surface and made by upper and lower molds. With the rapid development of the automobile industry, the shapes and structures of wheel hubs have also diversified. The cylinders of some wheel hubs are partially concave, and it is impossible to directly split the molds up and down at the maximum size, that is, the flange. It is necessary to design an outer core to solve the problem of local non-forming.

[0003] The outer surface of the existing outer core is convex outward, and the outer core can be directly split up and down to open the mold. The outer core that can be directly split up and down to open the mold is simple to make, but the wall thickness of the outer core is large and the weight is also large. The material for making the outer core includes coated sand, which is a molding sand with resin, curing agent and other additives coated on the surface. The wall thickness of the outer core is large. When casting the wheel hub, the resin, curing agent and other additives in the coated sand will produce smoke and irritating gases when exposed to high temperature, resulting in a greatly increased risk of pores in the wheel hub, which reduces the yield rate of the wheel hub casting. Utility Model Content

[0004] The purpose of the present application is to provide an outer shell core and a casting box to reduce the risk of air holes in the wheel hub and improve the yield rate of the wheel hub casting.

[0005] In order to achieve the above object, the present application provides an outer shell core for forming an annular groove structure of a casting, wherein the casting includes a wheel hub, and the outer shell core includes:

[0006] An axial connection portion, arranged around the casting, and used to form a bottom surface of the annular groove structure;

[0007] A first outer edge portion, the axial connection portion having an upper end and a lower end opposite to each other, the first outer edge portion being arranged at the upper end of the axial connection portion and used for forming an upper side wall of the annular groove structure;

[0008] a second outer edge portion, the second outer edge portion being disposed at a lower end of the axial connecting portion and being used to form a lower side wall of the annular groove structure;

[0009] Among them, the axial connecting portion is recessed relative to the first outer edge portion and the second outer edge portion to form a weight-reducing groove, the height of the first outer edge portion relative to the axis of the annular groove structure is H1, the height of the second outer edge portion relative to the axis of the annular groove structure is H2, and the height of the bottom surface of the weight-reducing groove relative to the axis of the annular groove structure is H3, H3 is smaller than H1 and H3 is smaller than H2.

[0010] Optionally, the outer shell core further includes first reinforcing ribs, a plurality of the first reinforcing ribs are arranged in the weight-reducing grooves, and the axial connection portion, the first outer edge portion and the second outer edge portion are all connected to the first reinforcing ribs.

[0011] Optionally, multiple first reinforcing ribs are respectively arranged on two opposite sides of the axial connection part, and any adjacent two first reinforcing ribs on the same side of the axial connection part are arranged in parallel. Multiple first reinforcing ribs divide the weight reduction groove into a first groove area and a second groove area. The first groove area is the area between adjacent first reinforcing ribs, and the second groove area is the side of the first reinforcing rib located on the outside away from the first groove area.

[0012] Optionally, the outer shell core further includes a second reinforcing rib, wherein the second reinforcing rib is arranged in the second groove area, and the second reinforcing rib is perpendicular to the first reinforcing rib.

[0013] Optionally, an outer surface of the first outer edge portion located in the first groove area protrudes outward to form a third reinforcing rib, and a protruding direction of the third reinforcing rib is perpendicular to the second reinforcing rib.

[0014] Optionally, part of the third reinforcing ribs connects the first outer edge portion and the second outer edge portion, and part of the third reinforcing ribs connects adjacent first reinforcing ribs.

[0015] The present application also provides a casting box, comprising:

[0016] A first structure, wherein the upper surface of the first structure is provided with at least one first cavity;

[0017] A second structure is arranged on the first structure, and the lower surface of the second structure is provided with at least one second cavity;

[0018] The outer shell core is arranged in the second mold cavity, and the inner wall of the outer shell core, the inner wall of the first mold cavity and the second mold cavity form a casting cavity for making a casting.

[0019] Optionally, a first step surface is formed on the inner wall of the second cavity, an end of a first outer edge portion of the outer shell core away from the axial connection portion is arranged on the first step surface, and an end of the first outer edge portion contacts the first structure.

[0020] Optionally, a second step surface is formed on the inner wall of the second cavity, the second step surface is located on the side of the first step surface away from the second structure, and the end of the second outer edge of the outer shell core away from the axial connection portion is arranged on the second step surface.

[0021] Optionally, a first sand collecting trough is provided on a side of the first step surface away from the pouring cavity; and / or

[0022] A second sand collecting trough is arranged on a side of the second step surface away from the pouring cavity.

[0023] The outer shell core and casting box disclosed in the present application have the following beneficial effects:

[0024] In the present application, an outer shell core is used to make a wheel hub. The outer shell core includes an axial connecting portion, a first outer edge portion and a second outer edge portion. The axial connecting portion is arranged around the wheel hub to form the bottom surface of the annular groove structure. The axial connecting portion has a relative upper end and a lower end. The first outer edge portion is arranged at the upper end of the axial connecting portion to form an upper side wall of the annular groove structure. The second outer edge portion is arranged at the lower end of the axial connecting portion to form a lower side wall of the annular groove structure. The axial connecting portion is recessed relative to the first outer edge portion and the second outer edge portion to form a weight-reducing groove. The weight-reducing groove can reduce the wall thickness of the outer shell core, reduce the total amount of smoke and irritating gases generated by additives such as resin and curing agent in the coated sand at high temperature, reduce the risk of air holes in the wheel hub, and improve the yield of the wheel hub casting.

[0025] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0026] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is a schematic diagram of the structure of the wheel hub in the embodiment of the present application.

[0029] Figure 2 It is a schematic diagram of the cooperation between the outer shell core and the wheel hub in the embodiment of the present application.

[0030] Figure 3 It is a three-dimensional schematic diagram of the outer shell core in the embodiment of the present application.

[0031] Figure 4 It is a schematic diagram of the existing outer core and wheel hub cooperation.

[0032] Figure 5 It is a schematic diagram of the outer shell core molding in the embodiment of the present application.

[0033] Figure 6 It is a cross-sectional schematic diagram of the casting box in the embodiment of the present application.

[0034] Figure 7 It is a three-dimensional schematic diagram of the casting box in the embodiment of the present application.

[0035] Figure 8 yes Figure 6 Enlarged schematic diagram of position A in the middle.

[0036] Description of reference numerals:

[0037] 100, wheel hub; 110, barrel; 111, ring groove structure; 120, flange; 200a, outer core;

[0038] 200, outer shell core; 210, axial connection portion; 220, first outer edge portion; 230, second outer edge portion; 240, first reinforcing rib; 250, second reinforcing rib; 260, third reinforcing rib; 201, weight reduction groove; 2011, first groove area; 2012, second groove area;

[0039] 300, first structure; 400, second structure; 401, first step surface; 402, second step surface; 403, first sand collecting trough; 404, second sand collecting trough;

[0040] 500, inner core; 610, pouring cavity; 620, pouring channel;

[0041] 710, upper core box; 720, lower core box; 730, core box movable block; 740, fixed plate; 750, cylinder. DETAILED DESCRIPTION

[0042] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0043] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the present application.

[0044] The present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be understood as limiting the present application.

[0045] See also Figure 1 and Figure 2 As shown, the wheel hub 100 includes a barrel portion 110 and a flange 120, and the flange 120 is arranged on the barrel portion 110, and the flange 120 is the largest outer circle of the wheel hub 100. When casting the wheel hub 100, the upper and lower molds are opened from the flange 120 of the wheel hub 100. In some technical solutions, an annular groove structure 111 is provided on the barrel portion 110 on one side of the flange 120, and the upper and lower molds cannot be opened directly at the maximum size, that is, the flange 120, and an outer shell core 200 needs to be designed to solve the problem of local non-molding.

[0046] See also Figure 2 and Figure 3 As shown, in this embodiment, the outer shell core 200 is used to form the annular groove structure 111 of the casting, and the casting includes the hub 100. The outer shell core 200 includes an axial connection portion 210, a first outer edge portion 220 and a second outer edge portion 230. The axial connection portion 210 is arranged around the casting, and the casting includes the hub 100. The axial connection portion 210 is used to form the bottom surface of the annular groove structure 111; the axial connection portion 210 has an upper end and a lower end opposite to each other, and the first outer edge portion 220 is arranged at the upper end of the axial connection portion 210 to form the upper side wall of the annular groove structure 111; the second outer edge portion 230 is arranged at the lower end of the axial connection portion 210 to form the lower side wall of the annular groove structure 111. In other words, the axial connection portion 210, the first outer edge portion 220 and the second outer edge portion 230 are integrally connected to form the hollow outer shell core 200, and part of the upper surface, part of the lower surface and the inner surface of the outer shell core 200 form the annular groove structure 111.

[0047] The axial connection portion 210 is recessed relative to the first outer edge portion 220 and the second outer edge portion 230 to form a weight-reducing groove 201. In other words, a weight-reducing groove 201 is formed on the outer surface of the outer shell core 200. The height of the first outer edge portion 220 relative to the axis of the annular groove structure 111 is H1, the height of the second outer edge portion 230 relative to the axis of the annular groove structure 111 is H2, and the height of the bottom surface of the weight-reducing groove 201 relative to the axis of the annular groove structure 111 is H3, and H3 is less than H1 and H3 is less than H2.

[0048] See also Figure 4As shown, the outer surface of the existing outer core 200a is convex outward. Although it can be directly produced by splitting the mold up and down, the outer core 200a has a large wall thickness and a large weight. The outer core 200a is made of coated sand, which is a molding sand with resin, curing agent and other additives wrapped on the surface. The outer core 200a has a large wall thickness. When casting the wheel hub 100, the resin, curing agent and other additives in the coated sand will produce smoke and irritating gases when exposed to high temperature, resulting in a greatly increased risk of pores in the wheel hub 100, which reduces the yield rate of the wheel hub 100 casting.

[0049] In this embodiment, the outer shell core 200 is used to manufacture the wheel hub 100. The outer shell core 200 includes an axial connection portion 210, a first outer edge portion 220, and a second outer edge portion 230. The axial connection portion 210 is arranged around the wheel hub 100 to form the bottom surface of the annular groove structure 111. The axial connection portion 210 has an upper end and a lower end opposite to each other. The first outer edge portion 220 is arranged at the upper end of the axial connection portion 210 to form the upper side wall of the annular groove structure 111. The second outer edge portion 230 is arranged at the upper end of the axial connection portion 210 to form the upper side wall of the annular groove structure 111. 0 is arranged at the lower end of the axial connection part 210, and is used to form the lower side wall of the annular groove structure 111. The axial connection part 210 is recessed relative to the first outer edge part 220 and the second outer edge part 230 to form a weight-reducing groove 201. The weight-reducing groove 201 can reduce the wall thickness of the outer shell core 200, reduce the total amount of smoke and irritating gas generated by additives such as resin and curing agent in the coated sand at high temperature, reduce the risk of pores in the wheel hub 100, and improve the yield rate of the wheel hub 100 casting.

[0050] In addition, the weight-reducing grooves 201 reduce the wall thickness and weight of the outer shell core 200 , reduce the consumption of coated sand, and reduce the material cost of manufacturing the outer shell core 200 .

[0051] See also Figure 2 and Figure 3 As shown, the outer shell core 200 further includes a first reinforcing rib 240, and a plurality of first reinforcing ribs 240 are disposed in the weight-reducing groove 201. The axial connection portion 210, the first outer edge portion 220 and the second outer edge portion 230 are all connected to the first reinforcing rib 240.

[0052] The outer shell core 200 is provided with a weight-reducing groove 201, and the wall thickness uniformity of the outer shell core 200 is better, which can reduce the curing deformation. A first reinforcing rib 240 is provided in the weight-reducing groove 201, and the first reinforcing rib 240 is supported between the first outer edge portion 220 and the second outer edge portion 230, and is connected to the axial connection portion 210, which can further enhance the structural strength of the outer shell core 200 and reduce the deformation of the outer shell core 200.

[0053] See also Figure 2 and Figure 3As shown, a plurality of first reinforcing ribs 240 are respectively arranged on opposite sides of the axial connection portion 210, and any two adjacent first reinforcing ribs 240 on the same side of the axial connection portion 210 are arranged in parallel. For example, three parallel first reinforcing ribs 240 are respectively arranged on both sides of the axial connection portion 210. The first reinforcing ribs 240 respectively located on both sides of the axial connection portion 210 can be symmetrically arranged relative to the axial connection portion 210, but are not limited thereto. The first reinforcing ribs 240 respectively located on both sides of the axial connection portion 210 can also be staggered, depending on the specific situation. The plurality of first reinforcing ribs 240 separate the weight reduction groove 201 into a first groove area 2011 and a second groove area 2012. The first groove area 2011 is the area between adjacent first reinforcing ribs 240, and the second groove area 2012 is the side of the first reinforcing ribs 240 located on the outside away from the first groove area 2011.

[0054] See also Figure 5 As shown, the forming mold of the outer shell core 200 includes an upper core box 710 and a lower core box 720, and a cavity for forming the outer shell core 200 is formed between the upper core box 710 and the lower core box 720, and the upper core box 710 and the lower core box 720 are used to form the upper end surface, the lower end surface and the inner cavity structure of the outer shell core 200. The forming mold of the outer shell core 200 also includes a core box movable block 730, a fixing plate 740 and a cylinder 750, and the two core box movable blocks 730 are arranged oppositely and located between the upper core box 710 and the lower core box 720, and are used to form the weight reduction groove 201 and its internal structure, that is, to form the first groove area 2011 and the second groove area 2012. The fixed plate 740 is arranged on two opposite sides of the lower core box 720, and the cylinder 750 is arranged on the fixed plate 740. The push rod of the cylinder 750 is connected to the core box movable block 730, and the cylinders 750 on both sides drive the relatively arranged core box movable blocks 730 to move closer to each other or move away from each other. When the core box movable blocks 730 move closer to each other and the upper core box 710 and the lower core box 720 are molded, the outer shell core 200 is molded in the mold cavity of the molding mold of the outer shell core 200, and when the core box movable blocks 730 move away from each other, the upper core box 710 and the lower core box 720 can move away from each other to take out the molded outer shell core 200.

[0055] Since the plurality of first reinforcing ribs 240 are respectively arranged on opposite sides of the axial connection portion 210, any two adjacent first reinforcing ribs 240 on the same side of the axial connection portion 210 are arranged in parallel, when manufacturing the outer shell core 200, the core box movable blocks 730 can be moved away from each other to take out the formed outer shell core 200, thereby solving the problem of the outer shell core 200 not being able to be shaped.

[0056] In addition, the wall thickness of the existing outer shell core 200a is large, and the curing time is long and the energy consumption is high when the outer shell core 200 is formed. The present application reduces the wall thickness and weight of the outer shell core 200 through the weight reduction groove 201, which can reduce the curing time of the outer shell core 200 and reduce the energy consumption of manufacturing the outer shell core 200.

[0057] See also Figure 2 and Figure 3 As shown, the outer shell core 200 further includes a second reinforcing rib 250, which is disposed in the second groove area 2012, and the second reinforcing rib 250 is perpendicular to the first reinforcing rib 240. The first reinforcing ribs 240 disposed on opposite sides of the outer shell core 200 can be symmetrically disposed relative to the second reinforcing rib 250. The second reinforcing rib 250 is supported between the first outer edge portion 220 and the second outer edge portion 230, and is connected to the axial connection portion 210 or the first reinforcing rib 240.

[0058] The second reinforcing rib 250 can enhance the structural strength of the outer shell core 200 and reduce the deformation of the outer shell core 200. At the same time, since the second reinforcing rib 250 is perpendicular to the first reinforcing rib 240, the second reinforcing rib 250 does not affect the formation of the weight-reducing groove 201 and the internal structure of the core box loose block 730.

[0059] See also Figure 2 and Figure 3 As shown, the outer surface of the first outer edge portion 220 located in the first groove area 2011 protrudes outward to form a third reinforcing rib 260, and the protruding direction of the third reinforcing rib 260 is perpendicular to the second reinforcing rib 250. In other words, the third reinforcing rib 260 protrudes in the moving direction of the core box movable block 730, so as to avoid the third reinforcing rib 260 affecting the formation of the weight-reducing groove 201 and the internal structure of the core box movable block 730.

[0060] The third reinforcing ribs 260 can enhance the structural strength of the outer shell core 200 and reduce the deformation of the outer shell core 200 .

[0061] In some embodiments, part of the third reinforcing ribs 260 connects the first outer edge portion 220 and the second outer edge portion 230, and part of the third reinforcing ribs 260 connects adjacent first reinforcing ribs 240. For example, the first outer edge portion 220 is located on the outer surface of each first groove area 2011 to form two third reinforcing ribs 260, and the two third reinforcing ribs 260 are vertically crossed to form a cross-shaped reinforcing rib structure.

[0062] Some third reinforcing ribs 260 connect the first outer edge portion 220 and the second outer edge portion 230 , and some third reinforcing ribs 260 connect adjacent first reinforcing ribs 240 . Multiple third reinforcing ribs 260 cross each other, which can further enhance the structural strength of the outer shell core 200 and reduce the deformation of the outer shell core 200 .

[0063] The present application also provides a casting box, which is used to make castings such as a wheel hub 100. Figure 6As shown, in this embodiment, the casting box includes an outer shell core 200, a first structure 300 and a second structure 400. The upper surface of the first structure 300 is provided with at least one first cavity, the second structure 400 is arranged on the first structure 300, and the lower surface of the second structure 400 is provided with at least one second cavity. The first structure 300 and the second structure 400 both include a box body and molding sand arranged in the box body, the first cavity is formed on the upper surface of the molding sand of the first structure 300, and the second cavity is formed on the lower surface of the molding sand of the second structure 400.

[0064] The casting box also includes an inner core 500, which is disposed in the first cavity and the second cavity. The outer shell core 200 is disposed in the second cavity and is sleeved on the inner core 500. The inner wall of the outer shell core 200, the inner wall of the first cavity and the second cavity form a pouring cavity 610 for making a casting, and the inner core 500 forms an inner cavity structure of the casting, and the casting includes a hub 100. The casting box may also include a runner 620, which is opened on the second structure 400 and can extend to the first structure 300. The casting box may include a plurality of pouring cavities 610, and the plurality of pouring cavities 610 are arranged around the runner 620. For example, four pouring cavities 610 are provided in each casting box.

[0065] When manufacturing a casting such as the wheel hub 100, the inner core 500 and the outer shell core 200 can be installed on the first structure 300, and then the second structure 400 and the first structure 300 are combined to form a casting cavity 610, and then the material for casting the wheel hub 100 is poured into the casting cavity 610 from the runner 620. After the material for casting the wheel hub 100 is solidified, the wheel hub 100 is formed.

[0066] In this embodiment, the casting box includes an outer shell core 200, which includes an axial connection portion 210, a first outer edge portion 220 and a second outer edge portion 230. The axial connection portion 210 is arranged around the hub 100 to form the bottom surface of the annular groove structure 111. The axial connection portion 210 has an upper end and a lower end opposite to each other. The first outer edge portion 220 is arranged at the upper end of the axial connection portion 210 to form the upper side wall of the annular groove structure 111. The second outer edge portion 230 is arranged at the lower end of the axial connection portion 210 to form the annular groove structure 111. The lower side wall of the groove structure 111 and the axial connecting portion 210 are recessed relative to the first outer edge portion 220 and the second outer edge portion 230 to form a weight-reducing groove 201. On the one hand, the weight-reducing groove 201 forms a cavity, which is beneficial to the extraction and discharge of pores during the pouring process. On the other hand, the weight-reducing groove 201 can reduce the wall thickness of the outer shell core 200, reduce the total amount of smoke and irritating gases generated by additives such as resin and curing agent in the coated sand at high temperature, reduce the risk of pores in the wheel hub 100, and improve the yield rate of the wheel hub 100 casting.

[0067] In addition, the existing outer core 200a is heavy, and the labor intensity of installing the outer shell core 200 is high. The present application reduces the weight of the outer shell core 200 through the weight-reducing groove 201, and can also reduce the labor intensity of installing the outer shell core 200.

[0068] See also Figure 8 As shown, the inner wall of the second cavity is formed with a first step surface 401, and the end of the first outer edge portion 220 of the outer shell core 200 away from the axial connection portion 210 is arranged on the first step surface 401, and the end of the first outer edge portion 220 contacts the first structure 300. In other words, the maximum outer circle size of the outer shell core 200 is greater than the maximum outer circle size of the hub 100, and the outer shell core 200 is pressed into the second cavity by the second structure 400.

[0069] The outer shell core 200 is made of coated sand, the density of which is about 1.6 grams per cubic millimeter, and the density of the molten iron used to make the hub 100 is about 6.9 grams per cubic millimeter, that is, the density of the material used to make the outer shell core 200 is much smaller than the density of the material used to make the hub 100. The outer shell core 200 is pressed into the second cavity by the second structure 400, which can prevent the outer shell core 200 from floating and affecting the manufacturing accuracy of the hub 100.

[0070] See also Figure 8 As shown, the inner wall of the second cavity is formed with a second step surface 402, which is located on the side of the first step surface 401 away from the second structure 400. The end of the second outer edge portion 230 of the outer shell core 200 away from the axial connection portion 210 is arranged on the second step surface 402.

[0071] The outer shell core 200 is arranged on two step surfaces, and the step surfaces and the second structure 400 are used together to limit the outer shell core 200, so as to prevent the movement of the outer shell core 200 from affecting the manufacturing accuracy of the hub 100.

[0072] See also Figure 8 As shown, a first sand collecting groove 403 is provided on the side of the first step surface 401 away from the pouring cavity 610 ; and / or a second sand collecting groove 404 is provided on the side of the second step surface 402 away from the pouring cavity 610 .

[0073] A first sand collecting trough 403 is provided on the side of the first step surface 401 away from the pouring cavity 610, and a second sand collecting trough 404 is provided on the side of the second step surface 402 away from the pouring cavity 610. The sand collecting trough can collect fine sand scraped off when installing the outer shell core 200, so as to prevent the fine sand from falling into the pouring cavity 610 and causing sand hole defects.

[0074] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the feature. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0075] In this application, unless otherwise clearly specified and limited, the terms "assembly", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0076] In the description of this specification, the description with reference to the terms "some embodiments", "exemplarily", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0077] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. Therefore, any changes or modifications made in accordance with the claims and description of the present application should fall within the scope of the patent of this application.

Claims

1. An outer shell core, used to form a ring groove structure of a casting, wherein the casting includes a wheel hub, characterized in that: The outer shell core comprises: An axial connection portion, arranged around the casting, and used to form a bottom surface of the annular groove structure; A first outer edge portion, the axial connection portion having an upper end and a lower end opposite to each other, the first outer edge portion being arranged at the upper end of the axial connection portion and used for forming an upper side wall of the annular groove structure; a second outer edge portion, the second outer edge portion being disposed at a lower end of the axial connecting portion and being used to form a lower side wall of the annular groove structure; Among them, the axial connecting portion is recessed relative to the first outer edge portion and the second outer edge portion to form a weight-reducing groove, the height of the first outer edge portion relative to the axis of the annular groove structure is H1, the height of the second outer edge portion relative to the axis of the annular groove structure is H2, and the height of the bottom surface of the weight-reducing groove relative to the axis of the annular groove structure is H3, H3 is smaller than H1 and H3 is smaller than H2.

2. The outer shell core according to claim 1, characterized in that: The outer shell core further includes first reinforcing ribs, a plurality of the first reinforcing ribs are arranged in the weight-reducing grooves, and the axial connection portion, the first outer edge portion, and the second outer edge portion are all connected to the first reinforcing ribs.

3. The outer shell core according to claim 2, characterized in that: The plurality of first reinforcing ribs are respectively arranged on two opposite sides of the axial connection portion, and any two adjacent first reinforcing ribs on the same side of the axial connection portion are arranged in parallel. The plurality of first reinforcing ribs divide the weight reduction groove into a first groove area and a second groove area. The first groove area is the area between adjacent first reinforcing ribs, and the second groove area is the side of the first reinforcing rib located on the outside away from the first groove area.

4. The outer shell core according to claim 3, characterized in that: The outer shell core further includes a second reinforcing rib, which is disposed in the second groove region and is perpendicular to the first reinforcing rib.

5. The outer shell core according to claim 4, characterized in that: The outer surface of the first outer edge portion located in the first groove area protrudes outward to form a third reinforcing rib, and the protruding direction of the third reinforcing rib is perpendicular to the second reinforcing rib.

6. The outer shell core according to claim 5, characterized in that: Part of the third reinforcing ribs connects the first outer edge portion and the second outer edge portion, and part of the third reinforcing ribs connects adjacent first reinforcing ribs.

7. A casting box, characterized in that: include: A first structure, wherein the upper surface of the first structure is provided with at least one first cavity; A second structure is arranged on the first structure, and the lower surface of the second structure is provided with at least one second cavity; The outer shell core according to any one of claims 1 to 6, wherein the outer shell core is arranged in the second cavity, and the inner wall of the outer shell core, the inner wall of the first cavity and the second cavity form a casting cavity for making a casting.

8. The casting box according to claim 7, characterized in that A first step surface is formed on the inner wall of the second cavity, and an end of a first outer edge portion of the outer shell core away from the axial connection portion is disposed on the first step surface, and an end of the first outer edge portion contacts the first structure.

9. The casting box according to claim 8, characterized in that The inner wall of the second cavity is formed with a second step surface, the second step surface is located on the side of the first step surface away from the second structure, and the end of the second outer edge of the outer shell core away from the axial connection portion is arranged on the second step surface.

10. The casting box according to claim 9, characterized in that A first sand collecting trough is provided on the side of the first step surface away from the pouring cavity; and / or A second sand collecting trough is arranged on a side of the second step surface away from the pouring cavity.

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