A casting mold for casting a casting with uniform hardness based on a non-contact chill

Abstract

The utility model discloses a kind of casting uniform hardness foundry mould based on non-contact cold iron, including foundry mould, the sprue cup is arranged on the surface of foundry mould, casting cavity is arranged in the inside of foundry mould, the casting cavity is communicated with sprue cup by pouring gate, cold iron setting cavity is arranged in the casting cavity periphery of foundry mould, the cold iron setting cavity is used to set cold iron, form non-contact cold iron.The utility model accurately controls casting local cooling speed by indirect cooling mode, avoids the defect caused by direct contact, solves the problem of casting hardness uneven.

Description

Technical Field

[0001] This utility model relates to the field of casting technology, specifically a casting mold for uniform hardness of castings based on non-contact chills. Background Technology

[0002] Uneven hardness is a common problem in casting production, especially in castings with large thickness variations and complex structures (such as engine blocks and gearbox housings). Uneven hardness can lead to difficulties in subsequent machining, inconsistent surface quality, and even affect the service life of parts.

[0003] In the prior art, the main methods to solve uneven hardness include: (1) adjusting the chemical composition (such as controlling the carbon and silicon content); (2) optimizing the casting process (such as controlling the casting temperature and speed); and (3) using contact chills to accelerate local cooling.

[0004] However, the above methods have limitations: chemical composition adjustment is limited by material performance requirements and it is difficult to accurately match local hardness requirements; casting process optimization is highly dependent on equipment precision and lacks stability; contact chills are in direct contact with castings, which can easily lead to indentations and deformation on the surface of castings; the interface between chills and castings is prone to porosity and sand inclusion defects due to gas or slag intrusion; and the cooling rate is affected by the contact area, which can easily form a hardness gradient.

[0005] As disclosed in announcement number CN106862494B, a method for manufacturing a 3D-printed sand core with a direct-cooling chill is described. The method involves designing a recess in the sand core area where the chill is to be installed. The recess has a sealing cap, integrally formed with the sand core, protruding from the casting outline and corresponding to the opening of the casting. During the 3D printing process, the sand core with the sealing cap is printed using a 3D printing device. Then, a flow coating is applied to the sand core. After the flow coating on the sand core surface dries, the chill is installed. During installation, the protruding sealing cap is ground off to expose the opening on the casting side of the recess. Loose sand is removed from the recess, and then the chill is fitted and fixed inside the recess. Finally, a refractory coating is applied to the exposed end face of the chill, completing the manufacturing of the 3D-printed sand core with the chill.

[0006] In this prior art, the chills are all in contact with the casting, which can easily lead to indentations and deformation on the surface of the casting.

[0007] Therefore, there is an urgent need for a non-contact local cooling technology that can achieve uniform hardness distribution by precisely controlling the cooling rate of key areas of the casting. Utility Model Content

[0008] In order to overcome the shortcomings of the prior art and solve at least one of the technical problems mentioned in the background art, this utility model provides a casting mold for uniform hardness of castings based on non-contact chills.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A casting mold for uniform hardness of castings based on non-contact chills includes a casting mold, a pouring cup on the surface of the casting mold, a casting cavity inside the casting mold, the casting cavity and the pouring cup being connected through a gating system, and a chill placement cavity on the outer periphery of the casting cavity of the casting mold for placing chills to form non-contact chills.

[0011] Furthermore, the casting mold is provided with a parting surface to form an upper mold and a lower mold, and the lower mold is provided with an isolation protrusion between the casting cavity and the chill placement cavity for isolation.

[0012] Furthermore, the casting mold has at least one set of symmetrical casting cavities inside, and a chill placement cavity is provided between each set of symmetrical casting cavities.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] This invention precisely controls the local cooling rate of castings through indirect cooling, avoiding defects caused by direct contact and solving the problem of uneven hardness in castings. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a casting mold for uniform hardness of castings based on a non-contact chill.

[0016] Figure 2 This is a structural schematic diagram of Embodiment 1 of the present invention.

[0017] Figure 3 This is a structural schematic diagram of Embodiment 2 of this utility model.

[0018] In the diagram: 1-Pour cup; 2-Sprue; 3-Glide runner; 4-Ingate; 5-Casting cavity; 6-Chiller placement cavity; 7-Upper mold; 8-Lower mold; 9-Parting surface; 10-Isolation protrusion. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Example 1:

[0021] Please see Figure 1 This utility model provides a casting mold for uniform hardness of castings based on non-contact chills, including a casting mold, a pouring cup 1 on the surface of the casting mold, a casting cavity 5 inside the casting mold, the casting cavity 5 and the pouring cup 1 being connected through a gating system, a chill placement cavity 6 on the outer periphery of the casting cavity 5 of the casting mold, and a chill placed in the chill placement cavity 6 to form a non-contact chill.

[0022] The gating system includes a sprue 2, a gating system 3, and an ingate 4, which are used to guide molten iron into the casting cavity 5.

[0023] In this embodiment, the casting mold is provided with a parting surface 9 to form an upper mold 7 and a lower mold 8. The lower mold 8 is provided with an isolation protrusion 10 between the casting cavity 5 and the chill placement cavity 6 to ensure uniform heat transfer and ensure the quality of the casting.

[0024] It should be noted that conventional technical solutions such as vents, risers, and overflow ports used to improve the quality of castings in casting molds are not shown in the drawings, but the structure and location of these conventional technical solutions are clear to those in the art.

[0025] The following steps are included when using it:

[0026] 1. Placement of chills during molding: During the molding process, the chills are placed in the chill placement cavity 6 next to the casting cavity 5 to ensure that the chills do not contact the casting. Then, sand is added to cover the chills and the mold 7 is installed.

[0027] 2. Melting and casting: Melt the molten metal to the target temperature (e.g., 1350~1450℃ for cast iron) and pour it into the casting cavity 5 along the gating system;

[0028] 3. Sequential cooling: After the molten metal fills the casting cavity 5, the chills indirectly cool the area to be strengthened in the casting cavity 5 (cooling rate 1~5℃ / s); the non-strengthened areas rely on natural cooling (cooling rate ≤0.5℃ / s).

[0029] 4. Mold opening and cleaning: After the casting has solidified, the mold is opened to remove paint residue and complete the casting process.

[0030] Example 2:

[0031] Please see Figure 1 This utility model provides a casting mold for uniform hardness of castings based on non-contact chills, including a casting mold, a pouring cup 1 on the surface of the casting mold, at least one set of symmetrical casting cavities 5 inside the casting mold, the casting cavities 5 and the pouring cup 1 are connected through a gating system, a chill placement cavity is provided between each set of symmetrical casting cavities 5, and a chill is placed in the chill placement cavity 6 to form a non-contact chill.

[0032] In this embodiment, the casting mold is provided with a parting surface 9 to form an upper mold 7 and a lower mold 8. The lower mold 8 is provided with an isolation protrusion 10 between the casting cavity 5 and the chill placement cavity 6 to ensure uniform heat transfer and ensure the quality of the casting.

[0033] The following steps are included when using it:

[0034] 1. Placement of chills during molding: During the molding process, the chills are placed in the chill placement cavity 6 between the two casting cavities 5 to ensure that the chills do not contact the castings. Then, sand is added to cover the chills and the mold 7 is installed.

[0035] 2. Melting and casting: Melt the molten metal to the target temperature (e.g., 1350~1450℃ for cast iron) and pour it into the casting cavity 5 along the gating system;

[0036] 3. Sequential cooling: After the molten metal fills the casting cavity 5, the chills indirectly cool the area to be strengthened in the casting cavity 5 (cooling rate 1~5℃ / s); the non-strengthened areas rely on natural cooling (cooling rate ≤0.5℃ / s).

[0037] 4. Mold opening and cleaning: After the casting has solidified, the mold is opened to remove paint residue and complete the casting process.

[0038] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0039] In this utility model, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0040] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0041] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0042] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A casting mold for uniform hardness of castings based on a non-contact chill, comprising a casting mold, a pouring cup disposed on the surface of the casting mold, a casting cavity disposed inside the casting mold, the casting cavity being connected to the pouring cup via a gating system, characterized in that, The casting mold has a chill placement cavity on the outer periphery of the casting cavity, which is used to place chills to form a non-contact chill.

2. The casting mold for uniform hardness of castings based on non-contact chills according to claim 1, characterized in that, The casting mold is provided with a parting surface to form an upper mold and a lower mold. The lower mold has an isolation protrusion between the casting cavity and the chill placement cavity for isolation.

3. The casting mold for uniform hardness of castings based on non-contact chills according to claim 1, characterized in that, The casting mold has at least one set of symmetrical casting cavities inside, and a chill placement cavity is provided between each set of symmetrical casting cavities.

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