Pouring system for controlling loose defect of stainless steel precision casting of impeller shaft

Abstract

The utility model relates to the field of impeller shaft pouring, in particular to a pouring system for controlling the loose defect of stainless steel precision casting of an impeller shaft, which comprises an impeller shaft mold, a pouring cup, a cross gate and two straight gates, a cavity is arranged in the impeller shaft mold, the pouring cup is communicated with the upper surface of the cross gate, and the two straight gates are communicated with the cavity. The lower surface of the transverse pouring gate is communicated with the straight pouring gate, the straight pouring gate is further provided with a stepped inner pouring gate, the stepped inner pouring gate is communicated with the mold cavity, the transverse pouring gate is provided with a vertical inner pouring gate, and the vertical inner pouring gate is communicated with the mold cavity. According to the utility model, the stepped ingate, the second connecting channel and the bottom pouring ingate are arranged, so that the mold filling of the impeller shaft mold can be carried out in stages, the generation of cavities and isolated liquid phase regions is avoided, the defects of casting finished products are reduced, and the product percent of pass is improved.

Description

Technical Field

[0001] This utility model relates to the field of impeller shaft casting, and in particular to a casting system for controlling porosity defects in stainless steel precision casting of impeller shafts. Background Technology

[0002] The impeller shaft is a key power component used to connect the impeller to the transmission system, and is widely used in rotating machinery such as centrifugal pumps and water turbines. The main body of this part has a stepped shaft structure, and the shaft end needs to form an interference fit with the impeller hub. Its interior contains cavities such as cooling channels and weight-reducing holes. These thin-walled areas and thick-walled transition zones are prone to stress concentration and defects such as shrinkage cavities and cracks during the casting process. Because the impeller shaft needs to withstand alternating torque and centrifugal loads, the casting must possess excellent fatigue resistance and dynamic balance characteristics, while ensuring the tightness of the inner wall of the channels to prevent media leakage.

[0003] Currently, traditional open-type casting systems struggle to achieve simultaneous filling of multiple cavities, easily leading to cold shuts and oxide inclusions. Therefore, it is necessary to improve this structure to overcome these shortcomings. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a casting system for controlling porosity defects in the precision casting of stainless steel impeller shafts. This invention is achieved through the following technical solution:

[0005] A gating system for controlling porosity defects in the precision casting of stainless steel impeller shafts includes an impeller shaft mold with a cavity inside. The mold also includes a pouring cup, a horizontal sprue, and two vertical sprues. The pouring cup is connected to the upper surface of the horizontal sprue, and the lower surface of the horizontal sprue is connected to the vertical sprues. A stepped ingate is provided on the vertical sprues and is connected to the cavity. A vertical ingate is provided on the horizontal sprue and is connected to the cavity.

[0006] In the above technical solution: the impeller shaft mold and cavity are used to ensure the accurate shape of the product obtained by casting; the sprue cup is used to receive the molten metal; the horizontal runner is used to transport the molten metal to the sprue and the vertical ingate; the vertical ingate is used to transport the molten metal to the upper part of the cavity; the sprue is used to transport the molten metal to the stepped ingate; the stepped ingate is used to transport the molten metal to the cavity at the flange position of the impeller shaft mold, which facilitates the forming of the flange structure.

[0007] A further feature of this invention is that the bottom surface of the stepped inlet is provided with an arc-shaped connection port, and the connection port is connected to the cavity through the flange portion of the impeller shaft mold.

[0008] In the above technical solution: the arc-shaped connection port makes the connection position between the stepped inlet and the impeller shaft mold larger, which facilitates the flow of molten metal into the cavity and also facilitates the escape of air bubbles in the mold.

[0009] A further feature of this invention is that it includes an auxiliary gating system, one end of which is connected to the pouring cup and the other end of which is connected to the horizontal gating system.

[0010] In the above technical solution: the auxiliary gating system is used to increase the flow rate of molten metal between the pouring cup and the runner.

[0011] A further feature of this invention is that the two sprues are spaced apart, and the impeller shaft mold is located between the two sprues.

[0012] In the above technical solution: the impeller shaft mold is located between two sprues, which facilitates the molten metal to enter the cavity from both sides of the impeller shaft mold, making the filling more uniform.

[0013] A further feature of this invention is that a second connecting channel is provided on the stepped inlet runner, the second connecting channel being connected to the cavity through the side of the impeller shaft mold, and the second connecting channel being connected to the cavity.

[0014] In the above technical solution: the second connecting channel is used to increase the flow of molten metal between the stepped ingate and the cavity, and to realize stepped pouring. Initially, the molten metal mainly flows through the lower connecting port. After the volume of molten metal in the cavity reaches a certain amount, the molten metal mainly flows through the second connecting channel.

[0015] A further feature of this invention is that a bottom-injection ingate is also connected to the bottom surface of the sprue, and the bottom-injection ingate is connected to the cavity through the side of the impeller shaft mold.

[0016] In the above technical solution, the bottom gating system is used to further improve the effect of stepped gating.

[0017] This utility model discloses a casting system for controlling porosity defects in the precision casting of stainless steel impeller shafts, which, compared with the prior art:

[0018] 1. This utility model, by setting a stepped ingate, a second connecting channel and a bottom-fill ingate, enables the filling of the impeller shaft mold to be carried out in stages, avoiding the generation of cavities and isolated liquid phase areas, reducing defects in the finished castings, and improving the product qualification rate.

[0019] 2. This utility model also provides an arc-shaped connection port, which makes the connection between the stepped inlet and the flange of the impeller shaft mold larger, facilitating the escape of air bubbles and reducing the possibility of air bubbles remaining in the flange position of the impeller shaft mold. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the present invention;

[0021] Figure 2 This is a schematic diagram of each gating channel of this utility model;

[0022] Figure 3 A schematic diagram of an embodiment of the present invention with a second connection channel;

[0023] Figure 4 This is a schematic diagram of an embodiment of the present invention with a bottom-injection gating system.

[0024] The numbers and letters in the diagram represent the following component names: 10-Impeller shaft mold; 20-Sprue cup; 30-Horizontal runner; 40-Vertical runner; 50-Stepped ingate; 501-Connecting port; 502-Second connecting channel; 60-Vertical ingate; 70-Auxiliary runner; 80-Bottom ingate. Detailed Implementation

[0025] The embodiments of this utility model are described in detail below. These embodiments are implemented based on the technical solution of this utility model and provide detailed implementation methods and specific operation processes. However, the protection scope of this utility model is not limited to the following embodiments.

[0026] like Figure 1-4 As shown, this utility model proposes a casting system for controlling porosity defects in the precision casting of stainless steel impeller shafts. The system includes an impeller shaft mold 10, which has a cavity. The system further includes a pouring cup 20, a horizontal runner 30, and two sprues 40. The pouring cup 20 is connected to the upper surface of the horizontal runner 30, and the lower surface of the horizontal runner 30 is connected to the sprues 40. A stepped ingate 50 is also provided on the sprues 40, and the stepped ingate 50 is connected to the cavity. A vertical ingate 60 is provided on the horizontal runner 30, and the vertical ingate 60 is connected to the cavity. The impeller shaft mold 10 includes a main body and flange portions disposed on both sides of the main body; the sprue cup 20 is disposed in the middle portion of the upper surface of the horizontal runner 30; the width of the stepped ingate 50 is smaller than that of the sprue 40, and the length of the stepped ingate 50 is not greater than that of the sprue 40; the number of vertical ingates 60 is two, and preferably, the two vertical ingates are symmetrically arranged about the sprue cup 20.

[0027] like Figure 1-4As shown, this utility model proposes a casting system for controlling porosity defects in the precision casting of stainless steel impeller shafts. The bottom surface of the stepped inlet sprue 50 is provided with an arc-shaped connection port 501, which communicates with the cavity through the flange portion of the impeller shaft mold 10. The dimensions of the connection port 501 correspond to the dimensions of the flange portion of the impeller shaft mold 10.

[0028] like Figure 1-4 As shown, the present invention proposes a gating system for controlling porosity defects in the precision casting of stainless steel impeller shafts, which further includes an auxiliary gating system 70. One end of the auxiliary gating system 70 is connected to the pouring cup 20, and the other end is connected to the horizontal gating system 30. The auxiliary gating system 70 has an inclination angle of 45 degrees. Preferably, the connection position between the auxiliary gating system 70 and the horizontal gating system 30 corresponds to the connection position between the vertical ingate 60 and the horizontal gating system 30, to facilitate the escape of air bubbles.

[0029] like Figure 1-4 As shown, the present invention proposes a casting system for controlling porosity defects in stainless steel precision casting of impeller shafts, wherein two sprues 40 are spaced apart, and the impeller shaft mold 10 is located between the two sprues 40.

[0030] like Figure 1-4 As shown, this utility model proposes a gating system for controlling porosity defects in the precision casting of stainless steel impeller shafts. The stepped ingate 50 is further provided with a second connecting channel 502. The second connecting channel 502 communicates with the cavity through the side of the impeller shaft mold 10. The second connecting channel 502 is horizontally positioned and located at the middle of the stepped ingate 50.

[0031] like Figure 1-4 As shown, this utility model proposes a gating system for controlling porosity defects in the precision casting of stainless steel impeller shafts. A bottom gating system 80 is also connected to the bottom surface of the sprue 40, and the bottom gating system 80 communicates with the cavity through the side of the impeller shaft mold 10. The bottom gating system 80 is horizontally positioned.

[0032] The working principle of this utility model is as follows:

[0033] a) Pour the molten metal from the pouring cup;

[0034] b) The molten metal enters the horizontal runner through the pouring cup, and a portion of the molten metal enters the mold cavity through the vertical ingate for filling;

[0035] c) Another portion of the molten metal enters the sprue and then flows through the sprue into the stepped ingate and the bottom-pour ingate.

[0036] d) The molten metal enters the mold cavity through a stepped ingate to ensure that the flange portion is filled;

[0037] e) The gas in the flange part of the cavity enters the stepped ingate from the connection port and then enters the sprue;

[0038] f) When the liquid level of the molten metal in the cavity exceeds the flange position, the molten metal preferentially enters the cavity from the second connecting channel.

[0039] Continue until the cavity is filled.

[0040] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A gating system for controlling the porosity defects of a stainless steel precision casting of an impeller shaft, comprising an impeller shaft mold (10) in which a mold cavity is provided, characterized in that: It also includes a sprue cup (20), a cross runner (30) and two straight runners (40), the sprue cup (20) communicates with the upper surface of the cross runner (30), the lower surface of the cross runner (30) communicates with the straight runner (40), the straight runner (40) is further provided with a stepped runner (50), the stepped runner (50) communicates with the cavity, the cross runner (30) is provided with a vertical runner (60), the vertical runner (60) communicates with the cavity.

2. The gating system for controlling the loose defect of the stainless steel precision casting of the impeller shaft according to claim 1, characterized in that: The bottom surface of the stepped runner (50) is provided with an arc-shaped connecting port (501), the connecting port (501) communicates with the cavity through the flange part of the impeller shaft mold (10).

3. The gating system for controlling the porosity defects of the stainless steel precision casting of the impeller shaft according to claim 2, characterized in that: It also includes an auxiliary runner (70), one end of the auxiliary runner (70) communicates with the sprue cup (20), the other end of the auxiliary runner (70) communicates with the cross runner (30).

4. The gating system for controlling the loose defect of the stainless steel precision casting of the impeller shaft according to claim 3, characterized in that: The two straight runners (40) are arranged at intervals, and the impeller shaft mold (10) is located between the two straight runners (40).

5. The gating system for controlling the porosity defects in the stainless steel investment casting of impeller shaft according to claim 4, wherein: The stepped runner (50) is further provided with a second connecting channel (502), the second connecting channel (502) communicates with the cavity through the side surface of the impeller shaft mold (10), and the second connecting channel (502) communicates with the cavity.

6. A gating system for controlling the porosity defects of a stainless steel investment casting of a turbine shaft according to claim 4 or 5, characterized in that: The bottom surface of the straight runner (40) is further provided with a bottom injection runner (80), the bottom injection runner (80) communicates with the cavity through the side surface of the impeller shaft mold (10).

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