Brake disc casting mold

Abstract

The utility model provides a brake disc casting mold. The brake disc casting mold comprises a lower sand tire, a lower mold, an inner core and an outer core, a boss, a groove and a positioning protrusion are arranged on the lower mold, and the lower mold can form a containing cavity, a supporting part and a positioning groove in the lower sand tire. The inner core is contained in the containing cavity, and the bottom of the inner core abuts against the top face of the supporting part so as to support the inner core. The outer core is provided with a containing channel, the outer core is arranged in the supporting part in a sleeved mode, meanwhile, the outer core is located on the periphery of the supporting part and the inner core, and the outer core and the inner core are arranged in a spaced mode. And a positioning part is arranged at the bottom of the inner core and can be clamped in the positioning groove, so that the inner core can be positioned in the accommodating cavity, the inner core is kept in a specific posture, and the casting qualification rate is increased. Besides, the through air outlet channel is formed in the inner core and can be communicated with the positioning groove, so that air in the positioning groove is exhausted along the air outlet channel during casting, the problems of sand holes, air holes and the like of the brake disc are avoided, and the appearance of a casting is improved.

Description

Technical Field

[0001] This utility model relates to the field of brake disc manufacturing technology, and in particular to a brake disc casting mold. Background Technology

[0002] Brake discs, also known as brake pads or brake discs, are a critical safety component in automobiles. They brake the wheels through friction with the brake pads. The reliability of the brake discs is crucial to driving safety. Brake failure in an emergency can easily lead to accidents, even fatal ones. Therefore, the manufacturing process for brake discs involves extremely stringent requirements to ensure their quality.

[0003] However, in the existing brake disc casting process, due to the complex structure of the brake disc, the casting is prone to problems such as sand holes and air holes in the outer tube. Furthermore, the cast brake disc is also prone to problems such as large wall thickness deviation, uneven shrinkage, and large burrs, which affect the subsequent processing steps of the brake disc and the production efficiency of the brake disc. Utility Model Content

[0004] The purpose of this invention is to provide a brake disc casting mold that can prevent the brake disc from having sand holes and air holes.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] According to one aspect of this utility model, a brake disc casting mold is provided for casting brake discs. The brake disc casting mold includes: a lower sand mold capable of casting; a lower mold capable of forming a receiving cavity, a support portion, and a positioning groove on the lower sand mold; the lower mold includes a boss with a bottom-opening groove, and a positioning protrusion connected to the boss within the groove, the positioning protrusion being connected to the top wall of the groove; when the lower mold is cast within the lower sand mold, the boss forms the receiving cavity, the groove forms the support portion, and the positioning protrusion forms the positioning groove; and an inner core housed within the receiving cavity, with the bottom of the inner core... The outer core abuts against the top surface of the support portion; the outer core is provided with a vertically penetrating receiving channel; the outer core is sleeved on the support portion and the outer periphery of the inner core located on the support portion, the outer core and the inner core are spaced apart, so that during casting, the cylinder of the brake disc is formed between the inner wall of the receiving channel and the outer wall of the inner core; wherein, the bottom of the inner core is provided with a downwardly protruding positioning portion, the positioning portion is engaged in the positioning groove, so that the inner core is limited in the receiving cavity; the inner core is provided with a vertically penetrating air outlet channel, and the bottom end of the air outlet channel is located at the positioning portion, after the positioning portion is engaged in the positioning groove, the air outlet channel can communicate with the positioning groove for exhaust.

[0007] In one embodiment of this application, the inner wall of the positioning groove includes a connected arc-shaped wall and a straight wall; the outer wall of the positioning part includes a connected arc-shaped surface and a straight surface; the arc-shaped wall is disposed corresponding to the arc-shaped surface, and the straight wall is disposed corresponding to the straight surface. When the positioning part is engaged in the positioning groove, the positioning groove can restrict the inner core from rotating along its vertical axis.

[0008] In one embodiment of this application, the gap between the arc-shaped wall and the arc-shaped surface is 0.25mm-0.35mm; the gap between the straight wall and the straight surface is 0.7mm-1.1mm.

[0009] In one embodiment of this application, a step is provided on the outer peripheral side of the boss so that the step can form a stepped portion within the receiving cavity during casting; the outer core includes an outer core and a brake core; the outer core includes a main body and a brake portion protruding outward from the outer peripheral wall of the main body; when the outer core is placed in the receiving cavity, the brake portion extends above the stepped portion; the brake core abuts against the brake portion so that a brake disc of the brake disc is formed between the brake portion and the brake core during casting.

[0010] In one embodiment of this application, a first abutting portion and a second abutting portion are respectively provided on the inner and outer peripheral sides of the brake portion; a first protrusion and a second protrusion are provided on the bottom of the brake core; the first protrusion and the second protrusion are respectively provided corresponding to the first abutting portion and the second abutting portion, so that when the brake core abuts against the brake portion, the first protrusion abuts against the first abutting portion and the second protrusion is located in the second abutting portion.

[0011] In one embodiment of this application, the gap between the bottom surface of the second abutment and the bottom surface of the second protrusion is 0.15mm-0.3mm.

[0012] In one embodiment of this application, the gap between the bottom surface of the brake part and the step surface of the step part is 0.3mm-0.7mm.

[0013] In one embodiment of this application, the brake disc casting mold further includes an upper mold and an upper sand mold capable of casting; the upper mold is provided with a venting column and a pouring column, and when the upper mold is casting in the upper sand mold, the pouring column is used to form a pouring channel, and the venting column is used to form an exhaust channel; the upper sand mold is used to cover the lower sand mold so that the pouring channel and the exhaust channel can both communicate with the space between the inner core and the outer core.

[0014] In one embodiment of this application, the lower sand mold is provided with a first casting channel and a plurality of inner casting channels, and the upper sand mold is provided with a second casting channel; when the upper sand mold is covered on the lower sand mold, one end of the first casting channel is connected to the casting channel, and the other end is connected to the second casting channel, and the second casting channel is connected to the space between the inner core and the outer core through the plurality of inner casting channels.

[0015] In one embodiment of this application, the first gating channel and the second gating channel have the same cross-sectional area; the cross-sectional area of ​​the gating orifice is greater than the cross-sectional area of ​​the first gating channel or the second gating channel; the cross-sectional area of ​​the first gating channel or the second gating channel is greater than the cross-sectional area of ​​the ingate; the ratio between the cross-sectional area of ​​the gating orifice, the cross-sectional area of ​​the first gating channel or the second gating channel, and the cross-sectional area of ​​the ingate is (1.4-2):(1.05-1.3):1.

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

[0017] In this invention, the brake disc casting mold includes a lower sand mold, a lower die, an inner core, and an outer core. The lower die is provided with bosses, grooves, and positioning protrusions, so that during casting, the lower die can form a receiving cavity, a support portion, and a positioning groove within the lower sand mold. The inner core is housed within the receiving cavity, and its bottom abuts against the top surface of the support portion to support it. The outer core is provided with a receiving channel, and while being fitted within the support portion, it is also located on the outer periphery of the support portion and the inner core, spaced apart from the inner core, so that during pouring, the inner core and the outer core can form the cylinder of the brake disc. Simultaneously, the bottom of the inner core is provided with a positioning portion, which can engage with the positioning groove, allowing the inner core to be positioned within the receiving cavity, maintaining a specific posture and improving the casting yield. In addition, the inner core is equipped with a through-hole venting channel that connects to the positioning groove, so that the gas in the positioning groove can be discharged along the venting channel during casting, thereby avoiding problems such as sand holes and air holes in the brake disc and improving the appearance of the casting. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the brake disc according to an embodiment of the present invention.

[0019] Figure 2 yes Figure 1 A schematic cross-sectional view of the brake disc.

[0020] Figure 3 yes Figure 1 A schematic diagram of the casting of the brake disc.

[0021] Figure 4 This is a schematic diagram of the lower mold of the brake disc casting mold according to an embodiment of this utility model.

[0022] Figure 5 yes Figure 4 A schematic diagram of the lower sand mold of the brake disc casting mold.

[0023] Figure 6 yes Figure 4 A schematic diagram of the inner and outer cores of the brake disc casting mold.

[0024] Figure 7 yes Figure 4 A schematic cross-sectional view of the lower sand mold, inner core, and outer core of the brake disc casting mold.

[0025] Figure 8 yes Figure 4 A schematic diagram of the outer core of the brake disc casting mold.

[0026] Figure 9 yes Figure 4 A schematic diagram of the upper mold of the brake disc casting mold.

[0027] Figure 10 yes Figure 4 A schematic diagram of the upper sand mold of the brake disc casting mold.

[0028] The annotations in the attached figures are explained as follows:

[0029] 10-Lower sand mold; 11-Accommodating cavity; 12-Support part; 13-Positioning groove; 14-First gating runner; 15-Inner gating runner; 20-Lower mold; 21-Boss; 22-Groove; 23-Positioning protrusion; 24-Step; 25-First gating protrusion; 26-Inner gating protrusion; 30-Inner core; 31-Positioning part; 32-Air vent; 40-Outer core; 41-Accommodating channel; 42-Outer core; 43-Brake core; 44-Main body; 45-Brake part; 50-Upper mold; 51-Ventilation column; 52-Gating column; 53-Second gating runner 60 - Upper sand mold; 61 - Casting channel; 62 - Exhaust channel; 63 - Second casting channel; 101 - Upper brake disc; 102 - Lower brake disc; 103 - Heat dissipation fin; 104 - Cylinder; 105 - Flange; 106 - Casting system; 111 - Stepped section; 131 - Arc-shaped wall; 132 - Straight wall; 311 - Arc-shaped surface; 312 - Straight surface; 431 - First protrusion; 432 - Second protrusion; 433 - Core rib; 451 - First abutment; 452 - Second abutment; 1021 - End; 1022 - End. Detailed Implementation

[0030] Typical embodiments embodying the features and advantages of this utility model will be described in detail in the following description. It should be understood that this utility model can have various variations in different embodiments, all of which do not depart from the scope of this utility model, and the descriptions and illustrations therein are for illustrative purposes only and not intended to limit this utility model.

[0031] In the description of this utility model, it should be understood that, in the embodiments shown in the accompanying drawings, the indications of direction or positional relationships (such as up, down, left, right, front, and back, etc.) are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. These descriptions are appropriate when these elements are in the positions shown in the accompanying drawings. If the description of the positions of these elements changes, these directional indications will also change accordingly.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] In existing brake disc casting processes, the complex structure of the brake disc makes it prone to problems such as sand holes and air pores in the outer tube. Furthermore, cast brake discs are also prone to large wall thickness deviations, uneven shrinkage, and excessively large burrs, thus affecting subsequent machining processes and production efficiency. Therefore, a brake disc casting mold is proposed to solve these problems.

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

[0035] Figure 1 This is a schematic diagram of the brake disc according to an embodiment of the present invention. Figure 2 yes Figure 1 A schematic cross-sectional view of the brake disc. Figure 3 yes Figure 1 A schematic diagram of the casting of the brake disc.

[0036] See Figure 1 , Figure 2 and Figure 3 The brake disc of this application includes an upper brake disc 101, a lower brake disc 102, heat dissipation fins 103, a cylinder 104, and a flange 105. The upper brake disc 101 and the lower brake disc 102 are spaced apart and located on opposite sides of the heat dissipation fins 103. Multiple heat dissipation fins 103 are provided and arranged in a circular array, with all fins 103 located between the upper brake disc 101 and the lower brake disc 102. The flange 105 is connected to the lower brake disc 102 via the cylinder 104.

[0037] Figure 4 This is a schematic diagram of the lower mold of the brake disc casting mold according to an embodiment of this utility model. Figure 5 yes Figure 4 A schematic diagram of the lower sand mold of the brake disc casting mold. Figure 6 yes Figure 4 A schematic diagram of the inner and outer cores of the brake disc casting mold. Figure 7 yes Figure 4 A schematic cross-sectional view of the lower sand mold, inner core, and outer core of the brake disc casting mold. Among them, [the following is a partial translation of the original text, which is incomplete and requires further context]. Figure 7 The vertical direction in the text refers to the vertical direction of the brake disc casting mold.

[0038] Please see Figure 4 , Figure 5 , Figure 6 and Figure 7 The brake disc casting mold of this embodiment can be used to cast brake discs.

[0039] Specifically, the brake disc casting mold includes a lower sand mold 10, a lower mold 20, an inner core 30, and an outer core 40.

[0040] The lower sand mold 10 is capable of casting, meaning that the lower sand mold 10 contains molding sand for casting, which, when combined with the lower mold 20, can produce the desired shape.

[0041] The lower mold 20 may include a boss 21, the bottom of which has an upwardly recessed groove 22, and the bottom of the groove 22 is open. Simultaneously, the groove 22 has a positioning protrusion 23 connected to the boss 21, and the positioning protrusion 23 is connected to the top wall of the groove 22. When the lower mold 20 is cast in the lower sand mold 10, the boss 21 can be used to form a receiving cavity 11, the groove 22 can be used to form an upwardly protruding support portion 12 at the bottom of the receiving cavity 11, and the positioning protrusion 23 can be used to form a downwardly recessed positioning groove 13 at the top of the support portion 12. That is, the lower mold 20 can form and obtain the receiving cavity 11, the support portion 12, and the positioning groove 13 on the lower sand mold 10.

[0042] The inner core 30 can be accommodated in the receiving cavity 11, and the bottom of the inner core 30 abuts against the top surface of the support part 12 to support the inner core 30. The bottom of the inner core 30 may have a downwardly protruding positioning part 31, the shape of which is adapted to the shape of the positioning groove 13, so that the positioning part 31 can engage in the positioning groove 13, thereby positioning the inner core 30 within the receiving cavity 11 and limiting the inner core 30 within the receiving cavity 11. This ensures that the posture of the inner core 30 relative to the lower sand mold 10 remains stable, thereby improving the casting yield.

[0043] It should be noted that when the positioning part 31 is engaged in the positioning groove 13, there can be a certain gap between the bottom of the positioning part 31 and the bottom surface of the positioning groove 13 to facilitate the expulsion of air. That is, the positioning part 31 does not serve to support the inner core 30; the inner core 30 is only supported by the top surface of the support part 12.

[0044] In this embodiment, the inner wall of the positioning groove 13 may include a connected arc-shaped wall 131 and a straight wall 132, and the outer wall of the positioning part 31 may include a connected arc-shaped surface 311 and a straight surface 312. Specifically, the arc-shaped wall 131 is provided corresponding to the arc-shaped surface 311, and the straight wall 132 is provided corresponding to the straight surface 312. When the positioning part 31 is engaged in the positioning groove 13, the positioning groove 13 can restrict the inner core 30 from rotating along its vertical axis, thus preventing the posture of the inner core 30 from changing during the casting process.

[0045] Meanwhile, the gap between the arc-shaped wall 131 and the arc-shaped surface 311 is 0.25mm-0.35mm, and the gap between the straight wall 132 and the straight surface 312 is 0.7mm-1.1mm, in order to facilitate venting and avoid problems such as air holes in the flange 105 and sand holes on the lower surface of the lower brake disc 102.

[0046] It should be noted that the curved wall 131 and the straight wall 132, as well as the curved surface 311 and the straight surface 312, all have a certain inclination in the vertical direction to facilitate demolding.

[0047] In some other embodiments, the horizontal cross section of the positioning groove 13 can be set as a rectangle or a triangle, etc. The positioning part 31 can be matched with the shape of the positioning groove 13, so that after the positioning part 31 is engaged in the positioning groove 13, the positioning part 31 and the positioning groove 13 can cooperate to achieve the positioning of the inner core 30 and restrict the rotation of the inner core 30 relative to the lower sand mold 10.

[0048] See Figure 6 and Figure 7 The inner core 30 can be provided with a vertically penetrating air outlet channel 32, and the bottom end of the air outlet channel 32 is located at the positioning part 31, so that after the positioning part 31 is engaged with the positioning groove 13, the air outlet channel 32 can connect with the positioning groove 13, so that the air in the positioning groove 13 can be discharged along the air outlet channel 32, thereby avoiding problems such as porosity and sand holes caused by poor gas discharge in the positioning groove 13 during casting, and thus improving the casting yield.

[0049] See Figure 6 and Figure 7 The outer core 40 may be provided with a receiving channel 41, and the receiving channel 41 extends vertically through the outer core 40. The outer core 40 is sleeved on the support portion 12 and the outer periphery of the inner core 30 located on the support portion 12, that is, the outer wall of the outer core 40 can fit against the inner wall of the receiving cavity 11, while the inner wall of the outer core 40 is spaced apart from the support portion 12 and the inner core 30. The inner core 30 is located in the receiving channel 41 so that during casting, the cylinder 104 of the brake disc is formed between the inner wall of the receiving channel 41 and the outer wall of the inner core 30.

[0050] It should be noted that the bottom shape of the receiving channel 41 matches the flange 105 so that the flange 105 of the brake disc can be formed at the bottom of the receiving channel 41 after casting.

[0051] See Figure 4 , Figure 5 and Figure 7 A step 24 is provided on the outer periphery of the boss 21 so that the step 24 can form a step portion 111 in the receiving cavity 11 during casting.

[0052] In this embodiment, the outer core 40 may include an outer core 42 and a brake core 43. The outer core 42 includes a main body 44 and a brake portion 45, which protrudes outward from the outer peripheral wall of the main body 44. When the outer core 42 is placed in the receiving cavity 11, the brake portion 45 extends above the stepped portion 111, and the brake core 43 abuts against the brake portion 45. During casting, a brake disc is formed between the brake portion 45 and the brake core 43, forming an upper brake disc 101, a lower brake disc 102, and multiple heat dissipation fins 103.

[0053] Specifically, the brake core 43 is provided with multiple core ribs 433, and the multiple core ribs 433 are arranged in a ring array. During casting, the multiple core ribs 433 can be used to form heat dissipation ribs 103.

[0054] Therefore, during casting, the upper brake disc 101, the lower brake disc 102, and the heat dissipation fins 103 of the brake disc can be formed at the brake part 45 and the brake core 43.

[0055] It should be noted that when the outer core 42 is placed inside the receiving cavity 11, the bottom of the outer core 42 abuts against the bottom surface of the receiving cavity 11, so that the bottom surface of the receiving cavity 11 can support the outer core 42 and prevent the outer core 42 from tilting when placed inside the receiving cavity 11. Simultaneously, a gap is formed between the bottom surface of the brake part 45 and the stepped surface of the stepped part 111 for venting, thereby preventing the cast brake disc from exhibiting uneven circumferential thickness or large circumferential thickness deviation. Specifically, in this embodiment, the gap between the bottom surface of the brake part 45 and the stepped surface of the stepped part 111 is 0.3mm-0.7mm.

[0056] Figure 8 yes Figure 4 A schematic diagram of the outer core of the brake disc casting mold.

[0057] See Figure 6 , Figure 7 and Figure 8 The brake part 45 has a first abutment part 451 and a second abutment part 452 respectively provided on its inner and outer peripheral sides, and the first abutment part 451 and the second abutment part 452 are located on the side of the brake part 45 away from the main body part 44. The brake core 43 has a first protrusion 431 and a second protrusion 432 at its bottom.

[0058] Specifically, the first protrusion 431 and the second protrusion 432 are respectively provided corresponding to the first abutment portion 451 and the second abutment portion 452. When the brake core 43 abuts against the brake portion 45, the first protrusion 431 abuts inside the first abutment portion 451, and the second protrusion 432 is located inside the second abutment portion 452. That is, the mating gap between the bottom surface of the first protrusion 431 and the bottom surface of the first abutment portion 451 is 0mm, so as to reduce burrs on the cylinder 104 of the brake disc blank. The second protrusion 432 is located inside the second abutment portion 452, but the bottom surface of the second protrusion 432 is spaced apart from the bottom surface of the second abutment portion 452.

[0059] In this embodiment, the gap between the bottom surface of the second abutment 452 and the bottom surface of the second protrusion 432 is 0.15mm-0.3mm, for venting.

[0060] Furthermore, it should be noted that during the cooling process of the casting, the shrinkage rate of the lower brake disc 102 varies at different positions in the radial direction. This causes the lower brake disc 102 to deform after cooling and shrinkage, resulting in the thickness of the lower brake disc 102 decreasing sequentially from the outer circumference to the inner circumference, thus causing the casting to be dimensionally unqualified. Simultaneously, the top surface of the brake part 45 located between the first abutment part 451 and the second abutment part 452 is an inclined surface. This inclined surface gradually slopes downward from the outer circumference of the brake part 45 towards the inner circumference, with the end of the inclined surface near the inner circumference of the brake part 45 being 0.8mm-1.3mm lower than the end near the outer circumference. Therefore, during the casting process, it is necessary to slightly increase the thickness of the lower brake disc 102 near the inner circumference so that the thickness of the lower brake disc 102 after cooling remains uniform, or to make the thickness of the lower brake disc 102 near the inner ring slightly greater than the thickness of the disc near the outer ring after cooling, so as to facilitate subsequent processing and prevent casting defects such as black skin and sand holes caused by insufficient machining allowance.

[0061] Figure 9 yes Figure 4 A schematic diagram of the upper mold of the brake disc casting mold. Figure 10 yes Figure 4 A schematic diagram of the upper sand mold of the brake disc casting mold.

[0062] See Figure 9 and Figure 10 The brake disc casting mold may also include an upper mold 50 and an upper sand mold 60 capable of casting.

[0063] The upper mold 50 is equipped with a venting column 51 and a pouring column 52. When the upper mold 50 is cast within the upper sand mold 60, the pouring column 52 forms the pouring channel 61, and the venting column 51 forms the venting channel 62. The upper sand mold 60 covers the lower sand mold 10, so that both the pouring channel 61 and the venting channel 62 can connect to the space between the inner core 30 and the outer core 40. During casting, the upper sand mold 60 and the brake core 43 together form the upper brake disc 101 of the brake disc.

[0064] It should be noted that when the upper sand mold 60 is placed on the lower sand mold 10, a relatively closed pouring space can be formed in the accommodating cavity 11, thereby avoiding defects such as sand holes and air holes in the cast brake disc.

[0065] See Figure 5 and Figure 10 The lower sand mold 10 is provided with a first gating channel 14 and multiple inner gating channels 15, and the upper sand mold 60 is provided with a second gating channel 63. When the upper sand mold 60 covers the lower sand mold 10, one end of the first gating channel 14 is connected to the gating hole 61, and the other end is connected to the second gating channel 63. The second gating channel 63 is connected to the space between the inner core 30 and the outer core 40 through multiple inner gating channels 15, so that the liquid material being poured can flow along the gating hole 61, the first gating channel 14, the second gating channel 63, and the inner gating channels 15 to the space between the inner core 30 and the outer core 40, and ultimately form a brake disc. Figure 3 As shown, after the pouring is completed, the pouring channel 61, the first pouring channel 14, the second pouring channel 63 and the ingate 15 together form the pouring system 106.

[0066] It should be noted that the lower mold 20 is provided with a first pouring protrusion 25 and an inner pouring protrusion 26, so that during casting, the first pouring protrusion 25 and the inner pouring protrusion 26 can respectively form a first gating channel 14 and an inner gating channel 15 on the lower sand mold 10. At the same time, the upper mold 50 is provided with a second pouring protrusion 53, so that during casting, the second pouring protrusion 53 can form a second gating channel 63 on the upper sand mold 60.

[0067] In this embodiment, the first gating channel 14 and the second gating channel 63 have the same cross-sectional area, the cross-sectional area of ​​the pouring channel 61 is larger than the cross-sectional area of ​​the first gating channel 14 or the second gating channel 63, and the cross-sectional area of ​​the first gating channel 14 or the second gating channel 63 is larger than the cross-sectional area of ​​the ingate 15, so that the liquid metal can flow uniformly from the ingate 15 to the space between the inner core 30 and the outer core 40, in order to prevent problems such as sand holes and air holes from appearing in the casting.

[0068] Specifically, the ratio between the cross-sectional area of ​​the pouring channel 61, the cross-sectional area of ​​the first pouring channel 14 or the second pouring channel 63, and the cross-sectional area of ​​the ingate 15 is (1.4-2):(1.05-1.3):1, to avoid defects such as sand holes and air holes in the cast brake disc, thereby improving the pass rate of the cast brake disc.

[0069] In summary, the brake disc casting mold includes a lower sand mold 10, a lower mold 20, an inner core 30, and an outer core 40. The lower mold 20 is provided with a boss 21, a groove 22, and a positioning protrusion 23, so that during casting, the lower mold 20 can form a receiving cavity 11, a support portion 12, and a positioning groove 13 within the lower sand mold 10. The inner core 30 is housed within the receiving cavity 11, and its bottom abuts against the top surface of the support portion 12 to support it. The outer core 40 is provided with a receiving channel 41. While the outer core 40 is fitted within the support portion 12, it is also located on the outer periphery of the inner core 30 within the support portion 12, and is spaced apart from the inner core 30, so that during pouring, the inner core 30 and the outer core 40 can form the cylinder 104 of the brake disc. Meanwhile, a positioning part 31 is provided at the bottom of the inner core 30. The positioning part 31 can be engaged in the positioning groove 13 so that the inner core 30 can be positioned in the receiving cavity 11, maintaining a specific posture to improve the casting yield. In addition, a through-hole venting channel 32 is provided inside the inner core 30, which can connect to the positioning groove 13. This allows the gas in the positioning groove 13 to be discharged along the venting channel 32 during casting, thereby avoiding problems such as sand holes and air holes in the brake disc, and thus improving the appearance of the casting.

[0070] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terminology used is descriptive and exemplary, and not restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A brake disc casting mold for casting brake discs, characterized in that the brake disc casting mold comprises: The lower sand mold is used for casting. The lower mold is capable of forming a receiving cavity, a support portion, and a positioning groove on the lower sand mold; the lower mold includes a boss, the boss has a groove with a bottom opening, and the groove also has a positioning protrusion connected to the boss, the positioning protrusion is connected to the top wall of the groove; when the lower mold is cast in the lower sand mold, the boss is used to form the receiving cavity, the groove is used to form the support portion, and the positioning protrusion is used to form the positioning groove; The inner core is housed within the receiving cavity, and the bottom of the inner core abuts against the top surface of the support portion; The outer core has a vertically penetrating receiving channel; The outer core is sleeved on the support portion and the outer periphery of the inner core located on the support portion. The outer core and the inner core are spaced apart so that, during casting, the cylinder of the brake disc is formed between the inner wall of the accommodating channel and the outer wall of the inner core. The inner core has a downwardly protruding positioning part at its bottom, which engages with the positioning groove to limit the inner core within the accommodating cavity. The inner core has a vertically penetrating air outlet channel, with the bottom end of the air outlet channel located at the positioning part. After the positioning part engages with the positioning groove, the air outlet channel can connect to the positioning groove for exhaust.

2. The brake disc casting mold according to claim 1, characterized in that, The inner wall of the positioning groove includes a connected arc-shaped wall and a straight wall; the outer wall of the positioning part includes a connected arc-shaped surface and a straight surface; the arc-shaped wall is provided corresponding to the arc-shaped surface, and the straight wall is provided corresponding to the straight surface. When the positioning part is engaged in the positioning groove, the positioning groove can restrict the inner core from rotating along its vertical axis.

3. The brake disc casting mold according to claim 2, characterized in that, The gap between the arc-shaped wall and the arc-shaped surface is 0.25mm-0.35mm; the gap between the straight wall and the straight surface is 0.7mm-1.1mm.

4. The brake disc casting mold according to claim 1, characterized in that, A step is provided on the outer peripheral side of the boss so that the step can form a stepped portion in the receiving cavity during casting. The outer core includes an outer core and a brake core; the outer core includes a main body and a brake portion protruding outward from the outer peripheral wall of the main body; when the outer core is placed in the receiving cavity, the brake portion extends above the stepped portion; the brake core abuts against the brake portion so that, during casting, a brake disc of the brake disc is formed between the brake portion and the brake core.

5. The brake disc casting mold according to claim 4, characterized in that, The brake part has a first abutting part and a second abutting part on its inner and outer peripheral sides, respectively; the brake core has a first protrusion and a second protrusion at its bottom; the first protrusion and the second protrusion are respectively provided corresponding to the first abutting part and the second abutting part, so that when the brake core abuts against the brake part, the first protrusion abuts against the first abutting part, and the second protrusion is located in the second abutting part.

6. The brake disc casting mold according to claim 5, characterized in that, The gap between the bottom surface of the second abutment and the bottom surface of the second protrusion is 0.15mm-0.3mm.

7. The brake disc casting mold according to claim 4, characterized in that, The gap between the bottom surface of the brake part and the step surface of the step part is 0.3mm-0.7mm.

8. The brake disc casting mold according to claim 4, characterized in that, It also includes an upper mold and an upper sand mold capable of casting; the upper mold is provided with a venting column and a pouring column, and when the upper mold is cast in the upper sand mold, the pouring column is used to form a pouring channel and the venting column is used to form an exhaust channel; the upper sand mold is used to cover the lower sand mold so that the pouring channel and the exhaust channel can both be connected to the space between the inner core and the outer core.

9. The brake disc casting mold according to claim 8, characterized in that, The lower sand mold is provided with a first pouring channel and a plurality of inner pouring channels, and the upper sand mold is provided with a second pouring channel; when the upper sand mold is covered on the lower sand mold, one end of the first pouring channel is connected to the pouring channel, and the other end is connected to the second pouring channel, and the second pouring channel is connected to the space between the inner core and the outer core through the plurality of inner pouring channels.

10. The brake disc casting mold according to claim 9, characterized in that, The first gating runner and the second gating runner have the same cross-sectional area; the cross-sectional area of ​​the gating channel is larger than the cross-sectional area of ​​the first gating runner or the second gating runner; the cross-sectional area of ​​the first gating runner or the second gating runner is larger than the cross-sectional area of ​​the ingate. The ratio between the cross-sectional area of ​​the pouring channel, the cross-sectional area of ​​the first pouring channel or the second pouring channel, and the cross-sectional area of ​​the ingate is (1.4-2):(1.05-1.3):1.

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