A mold for brake drum casting

Abstract

The present invention relates to a brake drum casting mold, comprising a first brake drum mold, a first riser mold, a first runner mold, and a pouring cup mold. The first brake drum mold is adapted to the shape of the brake drum to be cast, the first brake drum mold is connected to the first riser mold, and the first riser mold is connected to the pouring cup mold via a first runner mold. A second riser mold is provided above and near the center of the first brake drum mold, and the second riser mold is connected to the first brake drum mold via a first runner mold. The first runner mold is located on a side of the second riser mold away from the inner gate. Using the brake drum casting mold of the present invention can significantly improve the casting quality of the brake drum, reduce the scrap rate of the brake drum casting, improve the safety of the brake drum, increase the service life of the brake drum, and reduce the manufacturing cost of the enterprise.

Description

Technical Field

[0001] The invention relates to a mold for casting a brake drum, belonging to the technical field of casting. Background Art

[0002] The brake drum is the friction element of a drum brake and a crucial component in a vehicle's braking system. Its quality is crucial to driving safety. Brake drums produced using integral casting offer advantages such as simple structure, ease of processing, and high heat capacity, and are primarily used on medium- and heavy-duty vehicles.

[0003] Brake drums cast using conventional casting processes are prone to forming casting defects such as subcutaneous pores and slag holes on their upper surfaces. Subcutaneous pores are common casting defects. These pores are circular or fissure-like (N pores) with a metallic sheen on the inner surface. These pores are precipitation-type pores. As the molten metal solidifies, the solubility of gases (O / N / H, etc.) decreases, creating conditions for bubble nucleation and growth. These pores precipitate as pores. These defects are commonly found on the upper surface of the casting or at the lowest point in the molten iron temperature, where gases are trapped by the rapidly cooling molten metal. Consequently, the scrap rate for brake discs can reach approximately 30%, severely impacting production costs.

[0004] In view of the shortcomings of the existing technology, the present invention provides a brake drum casting mold, which improves the finished product rate of brake drum casting by improving the casting mold. Summary of the Invention

[0005] The purpose of the present invention is to provide a new technical solution to improve or solve the technical problems existing in the prior art as described above.

[0006] The present invention provides a mold for casting a brake drum, comprising a first brake drum mold, a first riser mold, a first cross runner mold and a pouring cup mold. The first brake drum mold is adapted to the shape of the brake drum to be cast, the first brake drum mold and the first riser mold are connected via a fifth runner mold, the first riser mold is connected to the pouring cup mold via a first cross runner mold, a second riser mold is provided above the first brake drum mold near the center, the second riser mold is connected to the first brake drum mold via a first runner mold, and the first runner mold is located on the side of the second riser mold away from the fifth runner mold.

[0007] The beneficial effects of the present invention are:

[0008] 1) When the brake drum is cast using the sand box produced by the brake drum casting mold of the present invention, the first step molten iron can be drained into the first riser cavity. Because the molten iron in the first step is most severely oxidized and passes through all positions of the cavity, it is the dirtiest. Draining the dirtiest molten iron in the first step from the first riser cavity can reduce slag holes on the surface of the brake drum. In addition, after the molten iron is drained into the first riser cavity, the heat node around the first riser cavity can be increased, and the cooling rate of the molten iron around the brake drum cavity can be slowed down, which is conducive to the emergence of bubbles and reduces the generation of subcutaneous pore defects on the upper surface of the brake drum. The use of the brake drum casting mold of the present invention can greatly improve the casting quality of the brake drum, reduce the scrap rate of the brake drum casting, improve the use safety of the brake drum, increase the service life of the brake drum, and reduce the manufacturing cost of the enterprise.

[0009] 2) The first runner mold is located on the side of the second riser mold away from the fifth runner mold. Since the molten iron has the inertia to flow forward, in the sand box, this is the last position where the molten iron flows after rising around the brake drum cavity, so drainage can be achieved in the largest range.

[0010] On the basis of the above technical solution, the present invention can also be improved as follows.

[0011] Furthermore, it also includes a second brake drum mold, which is adapted to the shape of the brake drum to be cast, and the first brake drum mold and the second brake drum mold are respectively arranged on both sides of the first riser mold, and the second brake drum mold is connected to the first riser mold through a sixth runner mold. A third riser mold is provided above the second brake drum mold near the center, and the third riser mold is connected to the second brake drum mold through a second runner mold. The second runner mold is located on the side of the third riser mold away from the sixth runner mold.

[0012] The beneficial effect of adopting the above further solution is that two brake drums can be quickly cast at one time, which greatly improves the production efficiency of the brake drums.

[0013] Furthermore, it also includes a mold base plate, on which the first brake drum mold, the second brake drum mold, the first riser mold, the first runner mold and the pouring cup mold are all embedded, and the first brake drum mold and the second brake drum mold both extend downward to below the mold base plate.

[0014] The beneficial effect of adopting the above further solution is that the brake drum casting mold of the present invention is embedded in the mold base plate, and the mold is fixed by the mold base plate, which can maintain the shape of the mold and increase the structural strength of the mold.

[0015] Furthermore, a cutting groove is provided at a position where the first drainage channel mold is connected to the first brake drum mold, and a cutting groove is also provided at a position where the second drainage channel mold is connected to the second brake drum mold.

[0016] The beneficial effect of adopting the above further solution is that the difficulty of separating the brake drum and the riser after casting is reduced.

[0017] Furthermore, a sprue mold is provided below the pouring cup mold, and the sprue mold is connected to the first runner mold.

[0018] Furthermore, the first cross runner mold includes an upper lap block, a lower lap block and a sprue casting nest mold, the upper lap block is arranged on the upper part of the mold base plate, the lower lap block and the sprue casting nest mold are arranged on the lower part of the mold base plate, the lower lap block, the upper lap block and the sprue casting nest mold are staggered above and below the mold base plate, and the sprue casting nest mold is located below the sprue.

[0019] The beneficial effect of adopting the above-mentioned further scheme is that a filter screen can be set between the lower overlap block cavity and the upper overlap block cavity. The molten iron first flows into the sprue pouring nest cavity through the pouring cup cavity, and then flows upward into the upper overlap block cavity. The molten iron in the upper overlap block cavity is filtered through the filter screen and then flows downward into the lower overlap block cavity, and finally flows into the brake drum cavity through the first riser cavity. Therefore, the upper and lower overlap structures of the lower overlap block, upper overlap block and sprue pouring nest mold can form an installation position for the filter screen in the sand box.

[0020] Furthermore, a second runner mold and a third runner mold are respectively connected on both sides of the first riser mold, the second runner mold is connected to the first brake drum mold through a third runner mold, and the third runner mold is connected to the second brake drum mold through a fourth runner mold.

[0021] The beneficial effect of adopting the above further solution is that the second runner mold and the third runner mold can increase the pouring channel in the sand box, which is beneficial to the sequential solidification of the casting and further reduces defects such as shrinkage and air holes in the product pipe fittings.

[0022] Furthermore, a first riser seat mold is provided below the mold base plate. The first riser seat mold is coaxially arranged with the first riser mold, and the first riser seat mold is connected to the lower overlapping block. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A top view of a brake drum casting mold according to the present invention;

[0024] Figure 2 It is a cross-sectional view taken along the line AA of the present invention;

[0025] Figure 3 A top view of the brake drum casting mold of the present invention mounted on a mold base;

[0026] Figure 4 A partial cross-sectional view of a flask produced using the mold of the present invention;

[0027] In the figure, 1, first brake drum mold; 2, first riser mold; 3, first runner mold; 4, gate cup mold; 5, second riser mold; 6, first runner mold; 7, second brake drum mold; 8, third riser mold; 9, second runner mold; 10, mold base; 11, cutting groove; 12, sprue mold; 13, upper lap block; 14, lower lap block; 15, sprue nest mold; 16, first riser seat mold; 17, second runner mold; 18, third runner mold; 1 9. Third runner mold; 20. Fourth runner mold; 21. Upper sand box; 22. Lower sand box; 23. Gate cup cavity; 24. Sprue cavity; 25. Sprue pouring nest cavity; 26. Upper lap block cavity; 27. Filter screen; 28. Lower lap block cavity; 29. ​​First riser seat cavity; 30. First riser cavity; 31. Second brake drum cavity; 32. Third riser cavity; 33. Ingate; 34. Fifth runner mold; 35. Sixth runner mold. DETAILED DESCRIPTION

[0028] The principles and features of the present invention are described below with reference to examples. The examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0029] like Figure 1-Figure 3 As shown, a mold for brake drum casting includes a mold base 10, and also includes a first brake drum mold 1, a first riser mold 2, a first cross runner mold 3 and a pouring cup mold 4 embedded in the mold base 10, the first brake drum mold 1 is adapted to the shape of the brake drum to be cast, the first brake drum mold 1 and the first riser mold 2 are connected through a fifth runner mold 34, the first riser mold 2 is connected to the pouring cup mold 4 through the first cross runner mold 3, a second riser mold 5 is provided above the first brake drum mold 1 near the center, the second riser mold 5 is connected to the first brake drum mold 1 through a first runner mold 6, and the first runner mold 6 is located on the side of the second riser mold 5 away from the fifth runner mold 34. In the sand box, the fifth runner mold 34 forms the inner gate 33 of the first brake drum mold 1. The inner gate 33 is the entrance for molten iron to flow into the first brake drum cavity, that is, during the casting process, the runner from the first brake drum mold 1 to the second riser mold 5 is kept away from the inner gate 33 of the first brake drum mold 1.

[0030] When the brake drum is cast using the sand box produced by the brake drum casting mold of the present invention, the first step of molten iron can be drained into the first riser cavity 30, thereby reducing slag holes and the like on the surface of the brake drum. In addition, after the molten iron is drained into the first riser cavity 30, the heat node around the first riser cavity 30 can be increased, and the cooling rate of the molten iron around the brake drum cavity can be slowed down, which is conducive to the emergence of bubbles and reduces the occurrence of subcutaneous pore defects on the upper surface of the brake drum.

[0031] In addition, in a specific embodiment,

[0032] The brake drum casting mold also includes a second brake drum mold 7, which enables rapid casting of two brake drums at once, significantly improving brake drum production efficiency. The second brake drum mold 7 matches the shape of the brake drum to be cast. The first and second brake drum molds 1 and 7 are positioned on either side of the first riser mold 2, respectively. The second brake drum mold 7 and the first riser mold 2 are connected via a sixth runner mold 35. A third riser mold 8 is positioned above and near the center of the second brake drum mold 7. The third riser mold 8 is connected to the second brake drum mold 7 via a second runner mold 9, which is located on the side of the third riser mold 8 away from the sixth runner mold 35. Within the flask, the sixth runner mold 35 forms an ingate 33 for the second brake drum mold 7. The ingate 33 serves as the entrance for molten iron to flow into the second brake drum cavity. This ensures that the runner from the second brake drum mold 7 to the third riser mold 8 is away from the ingate 33 of the second brake drum mold 7 during casting.

[0033] The first runner mold 6 is connected to the first brake drum mold at a location where a cutting groove 11 is provided. The second runner mold 9 is also connected to the second brake drum mold at a location where a cutting groove 11 is provided. The design of the cutting groove 11 can reduce the difficulty of separating the brake drum from the riser after casting.

[0034] The first brake drum mold 1, the second brake drum mold 7, the first riser mold 2, the first runner mold 3 and the pouring cup mold 4 are all embedded in the mold base plate 10, and the first brake drum casting mold is embedded in the mold base plate 10. The mold is fixed by the mold base plate 10, which can maintain the shape of the mold and increase the structural strength of the mold. In addition, the first brake drum mold 1 and the second brake drum mold 7 both extend downward to below the mold base plate 10. The first runner mold 3 includes an upper lap block 13, a lower lap block 14, and a sprue mold 15. The upper lap block 13 is arranged on the upper part of the mold base 10, and the lower lap block 14 and the sprue mold 15 are arranged on the lower part of the mold base 10. The lower lap block 14, the upper lap block 13, and the sprue mold 15 are staggered above and below the mold base 10 to form the installation position of the filter screen 27 in the sand box. A sprue mold 12 is also provided below the pouring cup mold 4, and the sprue mold 15 is located below the sprue mold 12. A first riser base mold 16 is also provided below the mold base 10. The first riser base mold 16 is coaxially arranged with the first riser mold 2 and connected to the lower lap block 14.

[0035] A second runner mold 17 and a third runner mold 18 are connected to both sides of the first riser mold 2. The second runner mold 17 is connected to the first brake drum mold 1 via a third runner mold 19, and the third runner mold 18 is connected to the second brake drum mold 7 via a fourth runner mold 20. The second runner mold 17 and the third runner mold 18 can increase the casting channel within the sand box, which is conducive to the sequential solidification of the casting and further reduces defects such as shrinkage and air holes in the product pipe fittings. A cutting groove 11 can also be provided at the location where the third runner mold 19 connects to the first brake drum mold 1, and a cutting groove 11 can also be provided at the location where the fourth runner mold 20 connects to the second brake drum mold 7.

[0036] The method for casting a brake drum using the brake drum casting mold of the present invention is as follows:

[0037] First, use the brake drum casting mold of the present invention to manufacture a sand box. The size of the selected sand box should be smaller than the size of the mold base 10. The upper sand box 21 and the lower sand box 22 are respectively buckled above and below the mold base 10, and then sand is respectively shot into the upper sand box 21 and the lower sand box 22. After unpacking and taking out the brake drum casting mold, a cavity that is compatible with the brake drum casting mold is formed in the upper and lower sand boxes 22.

[0038] like Figure 4The figure shows a partial cross-sectional view of the sand box. When the upper sand box 21 and the lower sand box 22 are buckled together, the brake drum casting cavity between the upper sand box 21 and the lower sand box 22 includes a first brake drum cavity, a second brake drum cavity 31, a first riser cavity 30, a second riser cavity, a third riser cavity 32, a first riser seat cavity 29, a pouring cup cavity 23, a straight runner cavity 24, an upper lap block cavity 26, a lower lap block cavity 28 and a straight runner pouring nest cavity 25, and a filter screen 27 is arranged between the upper lap block cavity 26 and the lower lap block cavity 28. The fifth runner mold 34 forms the inner gate 33 of the first brake drum mold 1, and the inner gate 33 of the first brake drum mold 1 is the entrance for molten iron to flow into the first brake drum cavity. The sixth runner mold 35 forms the inner gate 33 of the second brake drum mold 7, and the inner gate 33 of the second brake drum mold 7 is the entrance for molten iron to flow into the second brake drum cavity 31.

[0039] When using the above-mentioned sand box for casting, molten iron is injected from the pouring cup cavity 23. In the first step, the molten iron flows through the sprue cavity 24, the sprue pouring nest cavity 25, the upper lap block cavity 26, the filter screen 27, the lower lap block cavity 28, the first riser seat cavity 29, the first riser cavity 30, the first brake drum cavity and the second brake drum cavity 31 in sequence, and then the dirtiest molten iron in the first step is drawn out from the second riser cavity and the third riser cavity 32 respectively. The drainage port of the second riser cavity is arranged on the side away from the inner gate 33 of the first brake drum cavity. Since the molten iron has the inertia of drainage forward, this is the position where the molten iron last flows after rising around the brake drum cavity, which can realize the maximum drainage of the molten iron in the first brake drum cavity; the drainage port of the third riser cavity 32 is arranged on the side away from the inner gate 33 of the second brake drum cavity 31, which can realize the maximum drainage of the molten iron in the second brake drum cavity 31.

[0040] The use of the brake drum casting mold of the present invention can greatly improve the casting quality of the brake drum, reduce the scrap rate of the brake drum casting, improve the use safety of the brake drum, increase the service life of the brake drum, and reduce the manufacturing cost of the enterprise.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A mold for casting a brake drum, comprising a first brake drum mold (1), a first riser mold (2), a first runner mold (3) and a pouring cup mold (4), wherein the first brake drum mold (1) is adapted to the shape of the brake drum to be cast, the first brake drum mold (1) and the first riser mold (2) are connected via a fifth runner mold (34), and the first riser mold (2) is connected to the pouring cup mold (4) via a first runner mold (3), characterized in that: A second riser die (5) is provided above the first brake drum die (1) near the center, the second riser die (5) being connected to the first brake drum die (1) via a first runner die (6), the first runner die (6) being located on a side of the second riser die (5) away from the fifth runner die (34); The fifth runner mold (34) forms an inner gate (33) of the first brake drum mold (1); It also includes a second brake drum mold (7), the second brake drum mold (7) is adapted to the shape of the brake drum to be cast, the first brake drum mold (1) and the second brake drum mold (7) are respectively arranged on both sides of the first riser mold (2), the second brake drum mold (7) and the first riser mold (2) are connected through a sixth runner mold (35), a third riser mold (8) is provided above the second brake drum mold (7) near the center, the third riser mold (8) is connected to the second brake drum mold (7) through a second runner mold (9), and the second runner mold (9) is located on a side of the third riser mold (8) away from the sixth runner mold (35); A sprue mold (12) is further provided below the pouring cup mold (4), and the sprue mold (12) is connected to the first runner mold (3); The first runner mold (3) comprises an upper lap block (13), a lower lap block (14) and a sprue pouring nest mold (15), wherein the upper lap block (13) is arranged on the upper part of the mold base plate (10), and the lower lap block (14) and the sprue pouring nest mold (15) are arranged on the lower part of the mold base plate (10), and the lower lap block (14), the upper lap block (13) and the sprue pouring nest mold (15) are arranged alternately above and below the mold base plate (10), and the sprue pouring nest mold (15) is located below the sprue mold (12).

2. The brake drum casting mold according to claim 1, wherein: The first brake drum mold (1), the second brake drum mold (7), the first riser mold (2), the first runner mold (3) and the pouring cup mold (4) are all embedded in the mold base (10), and the first brake drum mold (1) and the second brake drum mold (7) both extend downward to below the mold base (10).

3. The brake drum casting mold according to claim 1, wherein: A cutting groove (11) is provided at the position where the first drainage channel mold (6) is connected to the first brake drum mold (1), and a cutting groove (11) is also provided at the position where the second drainage channel mold (9) is connected to the second brake drum mold (7).

4. The brake drum casting mold according to claim 1 or 2, characterized in that: A second runner mold (17) and a third runner mold (18) are respectively connected to both sides of the first riser mold (2); the second runner mold (17) is connected to the first brake drum mold (1) via a third runner mold (19); and the third runner mold (18) is connected to the second brake drum mold (7) via a fourth runner mold (20).

5. The brake drum casting mold according to claim 1, wherein: A first riser seat mold (16) is further provided below the mold base plate (10), the first riser seat mold (16) being coaxially arranged with the first riser mold (2), and the first riser seat mold (16) being connected to the lower lap block (14).

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