Sand core for hub casting

Abstract

The utility model provides a sand core for hub casting. The sand core comprises an upper core head, a lower core head and an inner core head, the upper core head is provided with a bearing part and a spoke part, and when the upper core head is used for preparing a sand tire, a bearing cavity and a spoke cavity which are communicated can be formed in the sand tire. And a spoke end part is arranged on the upper surface of the lower core head, so that when the hub is cast, the spoke end part can form the end part of the hub. And a positioning groove is formed in the end part of the spoke. The inner core head is placed at the end of the spoke, when the sand tire is assembled to the lower core head, the top of the inner core head can stretch into the bearing cavity and the spoke cavity, and the inner core head forms a center hole of the hub during pouring. A supporting part and a positioning part are arranged at the top and the bottom of the inner core head correspondingly, and the supporting part is supported on the top wall of the bearing cavity so as to support the sand tire. The positioning part is clamped in the positioning groove so as to support the inner core head and limit the inner core head to rotate around the axis of the inner core head, the inner core head is prevented from inclining or rotating in the casting process, and the yield of hub casting is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of wheel hub production, in particular to a sand core used for wheel hub casting. Background Art

[0002] The wheels used in commercial vehicles are generally cast from ductile iron. Due to the complexity of the wheel structure and the particularity of ductile iron, in actual production, most of the wheels are cast as blanks and then processed to obtain qualified wheel components. In the casting process, green sand is often used for core shaping to facilitate subsequent pouring.

[0003] However, wheel hub castings produced with green sand are prone to defects such as pores and sand holes on the end face of the bearing hole. Since the strength of the sand tire is not high and the height of the casting is much larger than the diameter of the inner cavity of the bearing hole, the core head of the wheel hub is prone to tilt or rotate during the casting process, resulting in the scrapping of the casting. Utility Model Content

[0004] The utility model aims to provide a sand core for wheel hub casting, which can limit the position of the sand core to prevent the core head from tilting or rotating during the casting process, thereby improving the casting yield.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] According to one aspect of the utility model, the utility model provides a sand core for wheel hub casting, comprising: an upper core head, the upper surface of which is provided with a connected bearing portion and a spoke portion; the bearing portion and the spoke portion are matched with the outer shape surfaces of the bearing and the spoke of the wheel hub respectively, so that when the upper core head is used to prepare the sand tire, the bearing portion and the spoke portion can form a connected bearing cavity and a spoke cavity in the sand tire; a lower core head, the upper surface of which is provided with a spoke end portion; the spoke end portion is matched with the outer end surface of the wheel hub, so that when casting, the spoke end portion can form the end of the wheel hub; An inner core head is placed on the end of the spoke, and when the sand tire is assembled to the lower core head, the top of the inner core head can extend into the bearing cavity and the spoke cavity, so that after pouring and casting, the center hole of the hub can be formed at the inner core head; wherein a positioning groove is provided in the end of the spoke; a supporting part and a positioning part are respectively provided at the top and bottom of the inner core head; the supporting part can be supported on the top wall of the bearing cavity to support the sand tire; the positioning part can be clamped in the positioning groove to support the inner core head and limit the rotation of the inner core head around its own axis.

[0007] In one embodiment of the present application, a positioning surface and a limiting portion recessed downward from the positioning surface are formed in the positioning groove; a top surface and a limiting protrusion protruding downward from the top surface are formed on the positioning portion; the top surface can abut against the positioning surface so that the positioning surface can support the inner core head; the limiting protrusion can be stuck in the limiting portion to limit the rotation of the inner core head around its own axis.

[0008] In one embodiment of the present application, the limiting protrusion includes a first raised rib and a second raised rib arranged to intersect each other; a first groove and a second groove are arranged in the limiting portion; the first groove and the second groove are arranged corresponding to the first raised rib and the second raised rib respectively, so that when the first raised rib and the second raised rib are respectively stuck in the first groove and the second groove, the side wall of the first groove can be against the side wall of the first raised rib, and the side wall of the second groove can be against the side wall of the second raised rib.

[0009] In one embodiment of the present application, an exhaust groove is further formed at the bottom edge of the positioning groove; the exhaust groove is formed by being recessed downward from the positioning surface to be used for squeezing sand and exhausting gas.

[0010] In one embodiment of the present application, in the axial direction of the inner core head, the height from the bottom of the limiting portion to the positioning surface is greater than the height from the bottom of the limiting protrusion to the abutting surface, so that after the limiting protrusion is stuck in the limiting portion, the bottom surface of the limiting protrusion and the bottom surface of the limiting portion are spaced apart.

[0011] In one embodiment of the present application, the diameter of the positioning groove is greater than the diameter of the positioning portion, so that when the positioning portion can be snapped into the positioning groove, the side wall of the positioning portion is spaced apart from the side wall of the positioning groove.

[0012] In one embodiment of the present application, the diameter of the support portion is smaller than the diameter of the spoke cavity, so that when the support portion is supported on the top wall of the bearing cavity, the side wall of the support portion is spaced apart from the side wall of the spoke cavity.

[0013] In one embodiment of the present application, a supporting surface and a boss protruding upward from the supporting surface are formed on the supporting portion; the supporting surface can abut against the top wall of the spoke cavity to support the sand tire; the boss can extend into the bearing cavity, and the side wall of the boss is spaced apart from the side wall of the bearing cavity.

[0014] In one embodiment of the present application, the inner core head includes two half cores that can be spliced ​​together, and the two half cores are symmetrically arranged along a plane passing through the central axis of the inner core head.

[0015] In one embodiment of the present application, the upper core head also includes an exhaust portion; the exhaust portion is connected to the top of the bearing portion, so that when the upper core head is preparing a sand tire, the exhaust portion can form an exhaust hole in the sand tire that is connected to the bearing cavity.

[0016] It can be seen from the above technical solution that the utility model has at least the following advantages and positive effects:

[0017] In the utility model, the sand core used for wheel hub casting includes an upper core head, a lower core head and an inner core head. The upper surface of the upper core head is provided with a connected bearing portion and a spoke portion, so that the upper core head can form a connected bearing cavity and a spoke cavity in the sand tire when preparing the sand tire. The upper surface of the lower core head is provided with a spoke end, so that when the wheel hub is cast, the spoke end can form the end of the hub. And a positioning groove is provided in the spoke end. The inner core head is placed on the spoke end, and when the sand tire is assembled on the lower core head, the top of the inner core head can extend into the bearing cavity and the spoke cavity, so that after casting, the center hole of the hub is formed at the inner core head. The top and bottom of the inner core head are respectively provided with a supporting portion and a positioning portion, and the supporting portion can be supported on the top wall of the bearing cavity to support the sand tire. The positioning portion can be snapped into the positioning groove to support the inner core head and limit the inner core head from rotating around its own axis, thereby preventing the inner core head from tilting or rotating during the casting process and improving the yield rate of wheel hub casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of a sand core for wheel hub casting according to an embodiment of the utility model.

[0019] Figure 2 yes Figure 1 Schematic diagram of the casting cavity formed by the upper core head of the sand core when preparing the sand tire.

[0020] Figure 3 yes Figure 1 Top view of the lower core head of the sand core.

[0021] Figure 4 yes Figure 1 Schematic diagram of half the lower core head of the sand core.

[0022] Figure 5 yes Figure 1 Front view of the inner core head of the sand core.

[0023] Figure 6 yes Figure 1 Schematic diagram of the inner core head of the sand core cooperating with the sand tire.

[0024] Figure 7 yes Figure 1 Schematic diagram of the inner core head and the lower core head of the sand core cooperating with each other.

[0025] Figure 8 yes Figure 7 A magnified view of point A.

[0026] Fig. 9 yes Figure 1 The intention of the half core of the inner core head of the sand core.

[0027] Fig.10 yes Figure 1 Bottom view of the inner core head of the sand core.

[0028] The following are the descriptions of the reference numerals:

[0029] 10-upper core head; 11-bearing part; 12-spoke part; 13-exhaust part; 20-lower core head; 21-spoke end; 22-positioning groove; 30-inner core head; 31-support part; 32-positioning part; 101-sand tire; 111-bearing cavity; 121-spoke cavity; 131-exhaust hole; 221-positioning surface; 222-limiting part; 223-first groove; 224-second groove; 225-exhaust groove; 301-half core; 311-support surface; 312-boss; 321-top surface; 322-limiting protrusion; 323-first protruding rib; 324-second protruding rib. DETAILED DESCRIPTION

[0030] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially for illustrative purposes rather than for limiting the present invention.

[0031] In the description of the present invention, it should be understood that in the embodiments shown in the drawings, the indications of directions or positional relationships (such as up, down, left, right, front and back, etc.) are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the descriptions of the positions of these elements change, the indications of these directions also change accordingly.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0033] Wheel hub castings produced by green sand are prone to defects such as pores and sand holes on the end face of the bearing hole. Since the strength of the sand mold is not high and the height of the casting is much larger than the diameter of the inner cavity of the bearing hole, the core head of the wheel hub is prone to tilt or rotate during the casting process, resulting in the scrapping of the casting. Therefore, a sand core for wheel hub casting is proposed to solve the above problems.

[0034] The scheme is further illustrated by the following examples:

[0035] Figure 1 It is a schematic diagram of a sand core for wheel hub casting according to an embodiment of the utility model. Figure 2 yes Figure 1 Schematic diagram of the casting cavity formed by the upper core head of the sand core when preparing the sand tire.

[0036] See also Figure 1 , the sand core of this embodiment can be used for casting of the wheel hub. That is, the sand core used for wheel hub casting can be used for shaping during the casting process of the wheel hub to obtain a casting mold that meets the requirements of wheel hub production. Specifically, the sand core used for wheel hub casting may include an upper core head 10, a lower core head 20, and an inner core head 30, and the upper core head 10 may form a casting cavity in the sand tire when preparing the sand tire. The lower core head 20 is connected to the sand tire, and the inner core head 30 is accommodated in the casting cavity to form the wheel hub after casting.

[0037] See also Figure 1 and Figure 2 The upper surface of the upper core head 10 can be provided with a connected bearing portion 11 and a spoke portion 12, and the bearing portion 11 and the spoke portion 12 are matched with the bearing mounting portion and the outer shape surface of the spoke of the wheel hub respectively, so that when the upper core head 10 is preparing the sand tire 101, the bearing portion 11 and the spoke portion 12 can form a connected bearing cavity 111 and a spoke cavity 121 in the sand tire 101, and then when the wheel hub is cast, the bearing cavity 111 and the spoke cavity 121 can form the bearing and spoke of the wheel hub.

[0038] In this embodiment, the upper core head 10 may further include an exhaust portion 13 .

[0039] Among them, the exhaust part 13 is connected to the top of the bearing part 11, so that when the upper core head 10 is preparing the sand tire 101, the exhaust part 13 can form an exhaust hole 131 connected to the bearing cavity 111 in the sand tire 101, and when casting, the air in the bearing cavity 111 and the spoke cavity 121 is discharged to avoid the formation of air holes on the hub casting, so as to improve the quality of the casting.

[0040] Figure 3 yes Figure 1 Top view of the lower core head of the sand core. Figure 4 yes Figure 1 Schematic diagram of half the lower core head of the sand core.

[0041] participate Figure 3 and Figure 4 The upper surface of the lower core head 20 may be provided with a spoke end 21 .

[0042] The spoke end 21 matches with the outer end surface of the hub, so that during casting, the spoke end 21 can form the end of the hub.

[0043] In this embodiment, a positioning groove 22 may be provided in the spoke end portion 21 , and the positioning groove 22 is used to clamp the inner core head 30 so as to position and support the inner core head 30 .

[0044] It should be noted that the lower core head 20 can be formed in one piece, or can be formed by splicing two symmetrical half lower core heads.

[0045] Figure 5 yes Figure 1 Front view of the inner core head of the sand core. Figure 6 yes Figure 1 Schematic diagram of the inner core head of the sand core cooperating with the sand tire. Figure 7 yes Figure 1 Schematic diagram of the inner core head and the lower core head of the sand core cooperating with each other. Figure 8 yes Figure 7 A magnified view of point A.

[0046] See also Figure 5 The inner core head 30 may include two half cores 301, and the two half cores 301 can be spliced ​​together to form the inner core head 30. Specifically, the two half cores 301 are symmetrically arranged along a plane passing through the central axis of the inner core head 30.

[0047] It should be noted that the inner core head 30 is configured as two half cores 301, which can facilitate the installation of the inner core head 30 on the lower core head 20, or facilitate the removal of the inner core head 30 after the pouring is completed. Specifically, when the two half cores 301 are actually used, glue is first applied on the splicing surface of the two half cores 301, so that the two half cores 301 can be spliced ​​together by glue.

[0048] In addition, a support portion 31 and a positioning portion 32 may be provided at the top and bottom of the inner core head 30 , respectively.

[0049] Specifically, Figure 6 and Figure 7 As shown, the inner core head 30 can be placed on the spoke end 21, and when the sand tire 101 is assembled to the lower core head 20, the top of the inner core head 30 can extend into the bearing cavity 111 and the spoke cavity 121, so that after pouring and casting, the center hole of the hub can be formed at the inner core head 30.

[0050] Specifically, the support portion 31 can be supported on the top wall of the bearing cavity 111 to support the sand tire 101. The positioning portion 32 can be snapped into the positioning groove 22 to support the inner core head 30 and limit the inner core head 30 from rotating around its own axis, so that after the inner core head 30 is placed on the sand tire 101 and the lower core head 20, the inner core head 30 can be prevented from rotating or tipping relative to the lower core head 20, so that the shape of the center hole formed at the inner core head 30 after casting remains accurate, thereby ensuring the yield of wheel hub casting.

[0051] See also Figure 3 , Figure 4 and Figure 5 A positioning surface 221 and a limiting portion 222 may be formed in the positioning groove 22, and the limiting portion 222 is formed to be recessed downward from the positioning surface 221. At the same time, a top surface 321 and a limiting protrusion 322 are formed on the positioning portion 32, and the limiting protrusion 322 is formed to be protruded downward from the top surface 321.

[0052] In this embodiment, the abutting surface 321 can abut against the positioning surface 221, so that the positioning surface 221 can support the inner core head 30. At the same time, the limiting protrusion 322 can be locked in the limiting portion 222, so that the limiting portion 222 and the side wall of the limiting protrusion 322 can abut against each other, and limit the rotation of the inner core head 30 around its own axis, thereby ensuring that the posture of the inner core head 30 relative to the lower core head 20 remains stable.

[0053] Fig. 9 yes Figure 1 Schematic diagram of the half core of the inner core head of the sand core. Fig.10 yes Figure 1 Bottom view of the inner core head of the sand core.

[0054] See also Figure 3 , Fig. 9 and Fig.10 The limiting protrusion 322 may include a first protrusion rib 323 and a second protrusion rib 324 that are intersectingly arranged, and a first groove 223 and a second groove 224 may be arranged in the limiting portion 222 .

[0055] Among them, the first groove 223 and the second groove 224 are respectively arranged corresponding to the first raised rib 323 and the second raised rib 324. When the first raised rib 323 and the second raised rib 324 are respectively stuck in the first groove 223 and the second groove 224, the side wall of the first groove 223 can be pressed against the side wall of the first raised rib 323, and the side wall of the second groove 224 can be pressed against the side wall of the second raised rib 324, so that a limit can be formed between the limiting protrusion 322 and the limiting part 222, and the inner core head 30 is limited from rotating relative to the lower core head 20.

[0056] It should be noted that the first raised rib 323 and the second raised rib 324 can be arranged perpendicular to each other, or they can form an angle, so that a limit is formed between the first raised rib 323 and the second raised rib 324 and the limiting portion 222 to prevent the inner core head 30 from rotating relative to the positioning groove 22.

[0057] In some other embodiments, the limiting protrusion 322 can be set as a rectangular column or a triangular column, and the limiting portion 222 can be correspondingly set as a rectangular groove or a triangular column groove, so that a limit can be formed between the limiting protrusion 322 and the limiting portion 222, and the inner core head 30 is limited from rotating relative to the lower core head 20.

[0058] participate Figure 4 and Figure 8 The bottom edge of the positioning groove 22 may also be formed with an exhaust groove 225. The exhaust groove 225 is formed by being recessed downward from the positioning surface 221 to be used for squeezing sand and exhausting air. That is, the exhaust groove 225 can accommodate sand particles that fall during the closing process to prevent the sand particles from affecting the casting.

[0059] In this embodiment, the diameter of the positioning groove 22 is larger than the diameter of the positioning portion 32, so that when the positioning portion 32 can be snapped into the positioning groove 22, the side wall of the positioning portion 32 is spaced apart from the side wall of the positioning groove 22, thereby allowing an exhaust passage to be formed between the side wall of the positioning portion 32 and the side wall of the positioning groove 22, thereby preventing the residual gas in the positioning groove 22 from affecting the casting during pouring.

[0060] It should be noted that a side wall of the exhaust groove 225 is connected to the side wall of the positioning groove 22 , so that the exhaust groove 225 can be connected to the exhaust channel formed between the side wall of the positioning portion 32 and the side wall of the positioning groove 22 for exhaust.

[0061] See also Figure 8 In the axial direction of the inner core head 30, the height from the bottom of the limiting portion 222 to the positioning surface 221 is greater than the height from the bottom of the limiting protrusion 322 to the abutting surface 321, so that after the limiting protrusion 322 is stuck in the limiting portion 222, the bottom surface of the limiting protrusion 322 and the bottom surface of the limiting portion 222 are spaced apart. That is, a cavity is formed between the bottom surface of the limiting protrusion 322 and the bottom surface of the limiting portion 222 to accommodate the fallen sand particles.

[0062] It should be noted that the side wall of the limiting protrusion 322 and the side wall of the limiting portion 222 may also be spaced apart to discharge the residual gas in the cavity formed between the bottom surface of the limiting protrusion 322 and the bottom surface of the limiting portion 222 .

[0063] In this embodiment, since the positioning surface 221 abuts against the abutting surface 321, the inner core head 30 is supported. At the same time, the limiting protrusion 322 is inserted into the limiting portion 222 to limit the rotation of the inner core head 30, so that the support and limiting of the inner core head 30 are set separately. In addition, the side wall of the positioning groove 22 and the side wall of the positioning portion 32 are spaced apart, and the side wall of the limiting portion 222 and the side wall of the limiting protrusion 322 are spaced apart, so that the positioning groove 22 and the positioning portion 32 can be vented. Therefore, through the above-mentioned setting, the inner core head 30 can be limited to ensure the accuracy of the inner core head 30, and the venting between the positioning groove 22 and the positioning portion 32 can be ensured, so as to avoid the formation of pores and sand holes in the casting, thereby improving the yield of the casting.

[0064] See also Figure 5 and Figure 6 A supporting surface 311 and a boss 312 are formed on the supporting portion 31 , and the boss 312 is formed to protrude upward from the supporting surface 311 .

[0065] The support surface 311 can abut against the top wall of the spoke cavity 121 to support the sand tire 101. At the same time, the support surface 311 abuts against the top wall of the spoke cavity 121 to prevent sand particles from falling into the spoke cavity 121 and prevent sand holes from forming in the casting.

[0066] In addition, the boss 312 can extend into the bearing cavity 111, so that the bearing cavity 111 can form a limit between the boss 312, and the bearing cavity 111 can limit the inner core head 30 to prevent the inner core head 30 from falling. At the same time, the side wall of the boss 312 and the side wall of the bearing cavity 111 can be spaced apart for exhaust.

[0067] In this embodiment, the diameter of the support portion 31 may be smaller than the diameter of the spoke cavity 121 , so that when the support portion 31 is supported on the top wall of the bearing cavity 111 , the side wall of the support portion 31 is spaced apart from the side wall of the spoke cavity 121 for exhaust.

[0068] In summary, the top and bottom of the inner core head 30 are respectively provided with a support portion 31 and a positioning portion 32, so that the support portion 31 and the positioning portion 32 can respectively cooperate with the bearing cavity 111 and the positioning groove 22 to limit the inner core head 30 and prevent the inner core head 30 from tipping over. At the same time, the positioning portion 32 is provided with a limiting protrusion 322, and the positioning groove 22 is provided with a limiting portion 222, so that the limiting portion 222 can limit the limiting protrusion 322 to prevent the inner core head 30 from rotating around its own axis, so that the inner core head 30 can be connected between the sand tire 101 and the lower core head 20 in a specific posture, thereby improving the yield of the casting.

[0069] In addition, the side walls of the support portion 31 and the positioning portion 32 are spaced from the side walls of the bearing cavity 111 and the positioning groove 22 for exhaust, thereby avoiding the formation of pores in the casting and improving the yield of the casting.

[0070] Although the utility model has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the utility model can be implemented in a variety of forms without departing from the spirit or essence of the utility model, it should be understood that the above-mentioned embodiments are not limited to any of the aforementioned details, but should be widely interpreted within the spirit and scope defined by the attached claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the attached claims.

Claims

1. A sand core for wheel hub casting, characterized in that: include: An upper core head, the upper surface of which is provided with a connected bearing portion and a spoke portion; the bearing portion and the spoke portion are matched with the outer surface of the bearing and the spoke of the wheel hub respectively, so that when the upper core head is used to prepare a sand tire, the bearing portion and the spoke portion can form a connected bearing cavity and a spoke cavity in the sand tire; A lower core head, the upper surface of which is provided with a spoke end; the spoke end matches the outer end surface of the hub so that the spoke end can form the end of the hub during casting; An inner core head is placed on the end of the spoke, and when the sand tire is assembled on the lower core head, the top of the inner core head can extend into the bearing cavity and the spoke cavity, so that after pouring and casting, the center hole of the hub can be formed at the inner core head; Among them, a positioning groove is arranged in the end of the spoke; a supporting part and a positioning part are respectively arranged on the top and bottom of the inner core head; the supporting part can be supported on the top wall of the bearing cavity to support the sand tire; the positioning part can be clamped in the positioning groove to support the inner core head and limit the rotation of the inner core head around its own axis.

2. The sand core for wheel hub casting according to claim 1, characterized in that: A positioning surface and a limiting portion recessed downward from the positioning surface are formed in the positioning groove; a top-butting surface and a limiting protrusion protruding downward from the top-butting surface are formed on the positioning portion; the top-butting surface can be pressed against the positioning surface so that the positioning surface can support the inner core head; the limiting protrusion can be stuck in the limiting portion to limit the rotation of the inner core head around its own axis.

3. The sand core for wheel hub casting according to claim 2, characterized in that: The limiting protrusion includes a first protruding rib and a second protruding rib arranged to intersect each other; a first groove and a second groove are arranged in the limiting portion; the first groove and the second groove are arranged corresponding to the first protruding rib and the second protruding rib respectively, so that when the first protruding rib and the second protruding rib are respectively stuck in the first groove and the second groove, the side wall of the first groove can be against the side wall of the first protruding rib, and the side wall of the second groove can be against the side wall of the second protruding rib.

4. The sand core for wheel hub casting according to claim 2, characterized in that: The bottom edge of the positioning groove is also formed with an exhaust groove; the exhaust groove is formed by being recessed downward from the positioning surface and is used for squeezing sand and exhausting gas.

5. The sand core for wheel hub casting according to claim 2, characterized in that: In the axial direction of the inner core head, the height from the bottom of the limiting portion to the positioning surface is greater than the height from the bottom of the limiting protrusion to the abutting surface, so that after the limiting protrusion is stuck in the limiting portion, the bottom surface of the limiting protrusion and the bottom surface of the limiting portion are spaced apart.

6. The sand core for wheel hub casting according to claim 1, characterized in that: The diameter of the positioning groove is greater than the diameter of the positioning portion, so that when the positioning portion can be snapped into the positioning groove, the side wall of the positioning portion is spaced apart from the side wall of the positioning groove.

7. The sand core for wheel hub casting according to claim 1, characterized in that: The diameter of the support portion is smaller than the diameter of the spoke cavity, so that when the support portion is supported on the top wall of the bearing cavity, the side wall of the support portion is spaced apart from the side wall of the spoke cavity.

8. The sand core for wheel hub casting according to claim 1, characterized in that: The support portion is formed with a support surface and a boss protruding upward from the support surface; the support surface can abut against the top wall of the spoke cavity to support the sand tire; the boss can extend into the bearing cavity, and the side wall of the boss is spaced apart from the side wall of the bearing cavity.

9. The sand core for wheel hub casting according to claim 1, characterized in that: The inner core head comprises two half cores which can be spliced ​​with each other, and the two half cores are symmetrically arranged along a plane passing through the central axis of the inner core head.

10. The sand core for wheel hub casting according to claim 1, characterized in that: The upper core head also includes an exhaust portion; the exhaust portion is connected to the top of the bearing portion, so that when the upper core head is used to prepare a sand tire, the exhaust portion can form an exhaust hole in the sand tire that is connected to the bearing cavity.

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