A casting mold structure for solving the sticking of sand to a casting

Abstract

The utility model discloses a casting mold structure that solves the sand sticking of castings, which comprises a casting mold, a sprue cup arranged on the surface of the casting mold, a castings cavity arranged in the casting mold, the sprue cup and the castings cavity being communicated through a sprue, the sprue comprising a straight sprue, a cross sprue and an inner sprue communicated in sequence, the straight sprue being arranged at the lower end of the sprue cup, a stepped flow resistance structure being arranged between the straight sprue and the cross sprue, the cross sprue having a larger diameter than the minimum diameter of the stepped flow resistance structure, a flow limiting channel being arranged between the cross sprue and the inner sprue, the flow limiting channel having a smaller diameter than the cross sprue, the inner sprue being communicated with the castings cavity, and the inner sprue expanding in diameter from the flow limiting channel to the castings cavity. The utility model optimizes the flow channel design of the pouring system, reduces the flow rate of molten iron before entering the cavity, reduces the mechanical scouring and chemical reaction on the sand, and thus reduces the sand sticking rate of the castings.

Description

Technical Field

[0001] This utility model relates to the field of casting technology, specifically a casting mold structure for solving the problem of sand adhesion in castings. Background Technology

[0002] In casting production, sand adhesion (especially mechanical sand adhesion) is a common problem. Sand adhesion manifests as molding sand particles adhering to the surface of the casting. In severe cases, it can lead to the scrapping of the casting or the need for additional cleaning processes, increasing production costs. The main causes of sand adhesion include: molten iron impacting the surface of the molding sand at high speed, breaking the bonding force between sand particles, causing sand particles to be entrained by the molten iron; and the high-temperature molten iron reacting chemically with components such as SiO2 in the molding sand to generate low-melting-point ferrous silicate (FeO·SiO2), which forms a sand adhesion layer after cooling.

[0003] In the existing technology, the main methods to solve the problem of sand adhesion include: (1) optimizing the properties of molding sand (such as improving refractoriness and reducing permeability); (2) applying anti-adhesion coating; and (3) adjusting the pouring temperature or speed. However, the above methods have limitations: the optimization of molding sand properties is limited by material costs and process stability; coating requires additional steps and is easy to fall off; simply reducing the pouring temperature may lead to insufficient fluidity of molten iron, causing defects such as cold shuts and shrinkage.

[0004] Announcement No. CN203426372U discloses a cam box casting sand mold structure. The cam box includes a base plate, a box wall located at the edge and middle of the base plate, and two pairs of fixing holes on the box wall for fixing a transmission mechanism and an open arm assembly, respectively. The casting sand mold structure includes a lower sand box, an upper sand box that is sealed and engaged with the lower sand box, and a cavity located at the interface between the upper and lower sand boxes corresponding to the cam box structure. The casting sand mold structure also includes multiple ingates located in the upper sand box and connected to the top of the cavity, a sprue located in the upper sand box and connected to the top of the sprue, and a sprue located in the upper sand box and connected to the sprue for pouring molten iron.

[0005] The existing technology reduces the flow rate by changing the direction of molten iron flow by making the sprue not directly opposite the ingate, but the molten iron still flows too fast under this method.

[0006] Therefore, there is an urgent need for a casting mold that can directly control the flow rate of molten iron through structural design, thereby reducing scouring and reaction, in order to efficiently solve the problem of sand adhesion. Utility Model Content

[0007] 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 structure for solving the problem of sand adhesion in castings.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A casting mold structure for solving sand adhesion in castings includes a casting mold, a pouring cup on the surface of the casting mold, and a casting cavity inside the casting mold. The pouring cup and the casting cavity are connected by a gating system, which includes a sprue, a runner, and an ingate connected in sequence. The sprue is located at the lower end of the pouring cup. A stepped flow-blocking structure is provided between the sprue and the runner, and the diameter of the runner is larger than the minimum diameter of the stepped flow-blocking structure. A flow-limiting channel is provided between the runner and the ingate, and the diameter of the flow-limiting channel is smaller than the diameter of the runner. The ingate is connected to the casting cavity and expands in diameter from the flow-limiting channel into the casting cavity.

[0010] Furthermore, the stepped surface of the stepped flow-blocking structure is a conical surface.

[0011] Furthermore, the diameter of the horizontal runner is greater than or equal to that of the vertical runner.

[0012] Furthermore, the flow restrictor has a flat structure, and the bottom surface of the flow restrictor is flush with the bottom surface of the horizontal runner.

[0013] Furthermore, the inner gating system is enlarged in diameter along the direction of the horizontal gating system via a conical surface.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] This invention reduces the flow rate of molten iron before it enters the mold cavity by optimizing the flow channel design of the gating system, thereby reducing the mechanical scouring and chemical reaction of the molding sand and thus reducing the sand adhesion rate of the casting. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a casting mold structure for solving the problem of sand adhesion in castings according to this utility model.

[0017] In the diagram: 1-Pour cup; 2-Sprue; 3-Stepped flow barrier; 4-Gateway; 5-Flow restrictor; 6-Ingate. Detailed Implementation

[0018] 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.

[0019] Please see Figure 1This utility model provides a casting mold structure for solving the problem of sand adhesion in castings, including a casting mold, a pouring cup 1 on the surface of the casting mold, a casting cavity inside the casting mold, the pouring cup 1 and the casting cavity being connected by a gating system, the gating system including a sprue 2, a runner 4 and an ingate 6 connected in sequence, the sprue 2 being located at the lower end of the pouring cup 1, a stepped flow-blocking structure 3 being provided between the sprue 2 and the runner 4, the diameter of the runner 4 being larger than the minimum diameter of the stepped flow-blocking structure 3, a flow-limiting channel 5 being provided between the runner 4 and the ingate 6, the diameter of the flow-limiting channel 5 being smaller than the diameter of the runner 4, the ingate 6 being connected to the casting cavity, and the ingate 6 expanding in diameter from the flow-limiting channel 5 into the casting cavity.

[0020] Among them, the stepped flow-blocking structure 3 causes the molten iron to be resisted, reducing the total pressure of the molten iron. After the molten iron passes through the stepped flow-blocking structure 3, the larger diameter of the horizontal gating channel 4 causes the molten iron to slow down and increase in pressure, but the total pressure is lower than before passing through the stepped flow-blocking structure 3. In the flow-limiting channel 5, the flow rate decreases after the diameter is reduced, and after the molten iron passes through the flow-limiting channel 5 at high speed, it slows down in the ingate 6 and enters the casting cavity at the lowest flow rate in the entire casting system.

[0021] Specifically, the stepped surface of the stepped flow-blocking structure 3 is a conical surface to prevent molten iron from accumulating at the steps.

[0022] Specifically, the diameter of the horizontal gating 4 is greater than or equal to that of the vertical gating 2, which helps to ensure that the flow rate of molten iron is reduced after passing through the stepped flow-blocking structure.

[0023] Specifically, the flow restriction channel 5 has a flat structure with a horizontal length greater than its vertical length. It restricts the flow rate of molten iron through the flow restriction hole, thereby reducing the flow velocity of molten iron after passing through the flow restriction channel 5. The bottom surface of the flow restriction channel 5 is flush with the bottom surface of the horizontal pouring channel 4 to prevent molten iron from climbing over the steps and forming an accumulation area when entering the flow restriction channel 5.

[0024] Specifically, the inner gating 6 is enlarged in diameter along the direction of the horizontal gating 4 via a conical surface.

[0025] Specifically, the flow restriction channel is connected to the middle of the horizontal gating 4, and the slag reaches the closed end of the horizontal gating 4 and is deposited under the action of inertia.

[0026] In this embodiment, the stepped flow-blocking structure 3 is a two-stage step, which reduces the total pressure of molten iron by step contraction, so that the flow rate of molten iron decreases after entering the horizontal pouring channel from the straight pouring channel.

[0027] Experiments have verified that casting molds using the structure of this utility model can reduce the sand adhesion rate of castings from 8%~12% in traditional processes to below 2%, and the surface roughness Ra value from 12.5μm to below 3.2μm, significantly improving casting quality and reducing cleaning costs.

[0028] 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, as well as casting cavities, are not drawn in the drawings. The structure and location of these conventional technical solutions are clear to those in the art.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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 structure for solving sand adhesion in castings, comprising a casting mold, wherein a pouring cup is provided on the surface of the casting mold, a casting cavity is provided inside the casting mold, the pouring cup and the casting cavity are connected by a gating system, wherein the gating system includes a sprue, a runner, and an ingate connected in sequence, characterized in that, The sprue is located at the lower end of the pouring cup, and a stepped flow-blocking structure is provided between the sprue and the runner. The diameter of the runner is larger than the minimum diameter of the stepped flow-blocking structure. A flow-limiting channel is provided between the horizontal runner and the ingate, and the diameter of the flow-limiting channel is smaller than that of the horizontal runner. The ingate is connected to the casting cavity, and the ingate expands in diameter from the flow-limiting channel into the casting cavity.

2. The casting mold structure for solving sand adhesion in castings according to claim 1, characterized in that, The stepped surface of the stepped flow-blocking structure is a conical surface.

3. The casting mold structure for solving sand adhesion in castings according to claim 1, characterized in that, The diameter of the horizontal runner is greater than or equal to that of the vertical runner.

4. The casting mold structure for solving sand adhesion in castings according to claim 1, characterized in that, The flow restrictor has a flat structure, and the bottom surface of the flow restrictor is flush with the bottom surface of the horizontal gating.

5. The casting mold structure for solving sand adhesion in castings according to claim 1, characterized in that, The ingate is enlarged along the direction of the runner by a conical surface.

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