Double-suction pump impeller forming method based on 3D printing

Abstract

The invention relates to a double suction pump impeller forming method based on 3D printing, which comprises the following steps: dividing a sand core of a double suction pump impeller casting into a bottom layer core, a lower impeller core, an upper impeller core and a cover core, respectively carrying out 3D printing, and carrying out mold closing pouring after the 3D printing is completed; wherein an auxiliary core groove is formed in the bottom of the bottom layer core, and a pouring gate auxiliary core is further embedded in the auxiliary core groove; reinforcing core heads are arranged on the two sides of the lower impeller core and the two sides of the upper impeller core respectively. And the bottom layer core, the lower impeller core, the upper impeller core and the cover core are sequentially stacked. The sand core of the double-suction pump impeller casting is divided into multiple parts to be subjected to 3D printing, and the problem that precise forming of a complex runner of a double-suction pump impeller is difficult to achieve through a traditional manufacturing process is solved. In addition, reinforcing core heads are arranged on the two sides of the lower impeller core and the two sides of the upper impeller core, and the stability and strength of the whole structure are enhanced.

Description

Technical Field

[0001] This invention relates to the field of casting technology, and in particular to a method for forming a dual-suction pump impeller based on 3D printing. Background Technology

[0002] The double-suction pump impeller is a core component for efficient and stable fluid transport, widely used in industrial, municipal, agricultural irrigation, and building water supply fields. Its unique bidirectional inlet design allows liquid to be drawn in from both sides of the impeller simultaneously, effectively balancing axial forces and improving operational stability. It is suitable for applications requiring high flow rates and medium to high head. With increasing demands for energy conservation and environmental protection, the application of double-suction pump impellers in high-efficiency energy-saving pumps and intelligent water supply systems will further expand, becoming one of the key technologies in modern fluid transport.

[0003] The double-suction pump impeller differs from the ordinary single-layer impeller. Its double-layer impeller structure poses a huge challenge to the casting process and molding scheme design. Conventional manual molding methods are almost impossible to meet the molding requirements of the two complex flow channels of the double-suction pump impeller. Summary of the Invention

[0004] Therefore, it is necessary to provide a 3D printing-based method for forming the complex structure of a double-suction pump impeller, addressing the challenge of its molding. This method includes:

[0005] The sand core of the double-suction pump impeller casting was divided into a bottom core, a lower impeller core, an upper impeller core, and a cover core, which were 3D printed separately. After 3D printing, the impeller was assembled and cast.

[0006] The bottom of the bottom core is provided with an auxiliary core groove, and the auxiliary core groove is also inlaid with a gating auxiliary core.

[0007] Reinforcing cores are provided on both sides of the lower impeller core and the upper impeller core, respectively;

[0008] The bottom core, the lower impeller core, the upper impeller core, and the cover core are stacked sequentially.

[0009] In this embodiment, by dividing the sand core of the double-suction pump impeller casting into multiple parts and 3D printing them separately, the problem of accurately forming the complex flow channel of the double-suction pump impeller, which is difficult to achieve with traditional manufacturing processes, is solved. Furthermore, by providing reinforcing core heads on both sides of the lower and upper impeller cores, the stability and strength of the overall structure are enhanced.

[0010] In one embodiment, a hanger handle is provided on the outer end face of the reinforcing core of the lower impeller core and the upper impeller core.

[0011] In this embodiment, the use of a frame with a handle facilitates the application of refractory coatings by flipping the frame with a robotic arm, thus solving the problem that surface quality cannot be guaranteed by normal manual brushing or spraying due to the narrow gap between the impeller core blades.

[0012] In one embodiment, an annular open riser is provided on the upper part of the cover core; a heating riser is provided at the intermediate shaft hole of the double suction pump impeller; and multiple concealed inclined risers are provided at the junction of the lower impeller core and the bottom core.

[0013] In this embodiment, by setting an annular open riser on the upper part of the cover core, setting a heating riser at the intermediate shaft hole of the double suction pump impeller, and setting multiple hidden inclined risers at the junction of the lower impeller core and the bottom core, the problem of thermal knots caused by inconsistent cooling rates in various key parts of the casting is solved, and the effect of effectively compensating for shrinkage and reducing internal defects in the casting is achieved.

[0014] In one embodiment, each of the aforementioned oblique risers is provided with an inner gate below it, and the pouring is performed using a bisection method.

[0015] In this embodiment, by setting an inner gate below each oblique riser and using a two-part pouring method, the problem of casting defects caused by uneven metal flow is solved, ensuring rapid and stable flow and improving the internal quality of the casting.

[0016] In one embodiment, a first connecting main beam is provided at the bottom of the lower impeller core, and a second connecting main beam is provided at the top of the upper impeller core.

[0017] In this embodiment, by setting a first connecting main beam at the bottom of the lower impeller core and a second connecting main beam at the top of the upper impeller core, the problem of the complex structure and insufficient strength of the middle impeller core is solved, thereby achieving the effect of enhancing the overall stability of the sand core structure and preventing breakage.

[0018] In one embodiment, the cover core is divided into two parts, which are respectively placed on both sides of the second connecting main beam of the upper impeller core.

[0019] In this embodiment, by dividing the cover core into two parts and placing them on both sides of the second connecting main beam of the upper impeller core, the interference problem between the cover core and the upper impeller core is solved, thereby simplifying the assembly process and maintaining structural stability and strength.

[0020] In one embodiment, corresponding positioning holes and positioning posts are respectively provided between the bottom core and the lower impeller core, between the lower impeller core and the upper impeller core, and between the upper impeller core and the cover core.

[0021] In this embodiment, by setting corresponding positioning holes and positioning posts, the problem of precise positioning between components is solved, thereby achieving the effect of preventing misalignment and improving the overall accuracy and stability after assembly. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the impeller of a double-suction pump;

[0023] Figure 2 This is a schematic diagram of the forming of a double-suction pump impeller provided in an embodiment of this application;

[0024] Figure 3A This is a schematic diagram of the underlying core provided in an embodiment of this application;

[0025] Figure 3B A schematic diagram of the core-in-core gating system provided in this application embodiment;

[0026] Figure 4A A front view of the lower impeller core provided in an embodiment of this application;

[0027] Figure 4B This is a schematic diagram of the bottom of the lower impeller core provided in an embodiment of this application;

[0028] Figure 5 A schematic diagram of the upper impeller core provided in an embodiment of this application;

[0029] Figure 6 This is a schematic diagram of the cover core provided in an embodiment of this application;

[0030] Figures 7A-7D This is a schematic diagram of the box closing process provided in an embodiment of this application. Detailed Implementation

[0031] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0032] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," "top," "bottom," "end," "top," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] The following describes the 3D printing-based double-suction pump impeller forming method with reference to specific embodiments. Please refer to [link / reference]. Figures 1-2 , Figure 1 This is a schematic diagram of the impeller of a double-suction pump; Figure 2 This is a schematic diagram of the process design of the double-suction pump impeller provided in an embodiment of this application.

[0035] like Figure 1 The schematic diagram of the double-suction pump impeller shown is shown. The double-suction pump impeller mainly includes an upper cover plate 1, a lower cover plate 2, two layers of blades (upper blade 3 and lower blade 4) and an intermediate shaft hole 5.

[0036] The 3D printing-based method for forming a double-suction pump impeller provided in this application first divides the overall sand core structure of the double-suction pump impeller casting into a bottom core, a lower impeller core, an upper impeller core, and a cover core. This division is based on the structural characteristics of the double-suction pump impeller, including the upper and lower blade structures, the intermediate shaft hole, and the complex flow channel system. Modular design makes each part easier to 3D print. Subsequently, the four parts are 3D printed separately. Using 3D printing technology can achieve complex geometries that are difficult to achieve with traditional casting processes. It is particularly suitable for the precise forming of structures such as interlaced upper and lower blades and narrow flow channels in double-suction pump impellers, improving the dimensional accuracy and surface quality of the casting.

[0037] Please refer to Figure 3A and Figure 3B , Figure 3A This is a schematic diagram of the underlying core provided in an embodiment of this application; Figure 3B This is a schematic diagram of the gating auxiliary core provided in an embodiment of this application. An auxiliary core groove 10 is provided at the bottom of the bottom core, and the gating auxiliary core 11 is embedded in the groove 10. This design allows for the integrated arrangement of the gating system, facilitating the guidance and filling of molten metal during subsequent box assembly. During installation, the bottom core is placed on its side, and the gating auxiliary core 11 is inserted into the auxiliary core groove 10 from the side. Alternatively, the gating auxiliary core 11 can be fixed using long nails or similar means. It should be noted that the gating auxiliary core 11 needs to be designed in several pieces.

[0038] In some implementations, it is necessary to control the length of the gating core to be no more than 400 mm and the weight to be no more than 20 kg in order to facilitate the installation operation.

[0039] Please refer to Figure 4A , Figure 4B and Figure 5 , Figure 4A This is a front view of the lower impeller core provided in an embodiment of this application; Figure 4B This is a schematic diagram of the bottom of the lower impeller core provided in the embodiments of this application; Figure 5 This is a schematic diagram of the upper impeller core provided in an embodiment of this application. To improve the structural strength of the lower and upper impeller cores during printing, handling, flow coating, and assembly, reinforcing core heads 12 are respectively provided on both sides of the lower and upper impeller cores. These reinforcing core heads 12 not only enhance the mechanical strength of the sand core but also provide structural support for subsequent operations.

[0040] Furthermore, a lifting handle 13 is provided on the outer end face of the reinforced core head of both the lower and upper impeller cores for gripping, flipping, and flow coating operations by a robotic arm. This design solves the problem that manual brushing or spraying cannot guarantee the quality of the surface coating due to the narrow gap between the impeller core blades, ensuring the uniformity and integrity of the flow coating operation. Simultaneously, the lifting handle also solves the problem of low strength and difficulty in lifting the intermediate impeller core, enhancing the overall strength of the sand core.

[0041] Furthermore, an annular open riser 6 is provided on the upper part of the cover core; a heating riser 7 is provided at the intermediate shaft hole of the double-suction pump impeller; and multiple concealed oblique risers 8 are provided at the junction of the lower impeller core and the bottom core. In this embodiment, by using a special riser method, an annular open riser is used to supplement the thermal knots formed by the upper cover plate and upper blades, and a circular oblique riser is used to supplement the thermal knots formed by the lower cover plate and lower blades. This solves the problem of thermal knots caused by inconsistent cooling rates in various key parts of the casting, achieving effective feeding and reducing internal defects in the casting.

[0042] Furthermore, in one embodiment, an inner gate is provided below each of the aforementioned oblique risers 8, and the casting is performed using a two-part method. In this embodiment, by providing an inner gate below each oblique riser and using a two-part method for casting, the problem of casting defects caused by uneven metal flow is solved, ensuring rapid and stable flow and improving the internal quality of the casting.

[0043] In one embodiment, a first connecting main beam 14 is provided at the bottom of the lower impeller core, and a second connecting main beam 17 is provided at the top of the upper impeller core. In this embodiment, by providing a first connecting main beam at the bottom of the lower impeller core and a second connecting main beam at the top of the upper impeller core, the problem of the complex structure and insufficient strength of the intermediate impeller core is solved, achieving the effect of enhancing the overall stability of the sand core structure and preventing breakage.

[0044] like Figure 6 As shown, Figure 6 This is a schematic diagram of the cover core provided in an embodiment of this application. In one embodiment, the cover core 16 is divided into two parts, which are respectively placed on both sides of the second connecting main beam of the upper impeller core. In this embodiment, by dividing the cover core into two parts and placing them on both sides of the second connecting main beam of the upper impeller core, the interference problem between the cover core and the upper impeller core is solved, thereby simplifying the assembly process and maintaining structural stability and strength.

[0045] In one embodiment, corresponding positioning holes 18 and positioning posts 15 are respectively provided between the bottom core and the lower impeller core, between the lower impeller core and the upper impeller core, and between the upper impeller core and the cover core. Through the positioning holes and positioning posts, this positioning structure prevents misalignment and displacement, improving the assembly accuracy and stability of the overall mold. Additionally, positioning blocks 19 can be provided on the outer sides of the bottom core and the lower impeller core to prevent displacement during the core lowering process.

[0046] like Figures 7A-7D The diagram shows the mold assembly process. The bottom core, lower impeller core, upper impeller core, and cover core are stacked and assembled in sequence to complete the mold assembly. The pouring operation is then performed, utilizing the aforementioned pouring system to ensure that the molten metal fills the entire mold evenly and smoothly, ultimately obtaining a high-quality double-suction pump impeller casting.

[0047] In this embodiment, by dividing the sand core of the double-suction pump impeller casting into multiple modules and 3D printing them separately, the problem of complex flow channel structures being difficult to achieve in traditional casting processes is solved. By incorporating a reinforced core head, a support frame, a riser system, a connecting main beam, a split-type core cover, and a positioning structure, the strength, assembly accuracy, and casting quality of the sand core structure are effectively improved. This invention is simple to operate, has high forming accuracy, and is suitable for the efficient and high-quality manufacturing of complex structural castings.

[0048] In summary, this application solves the problem of complex flow channel structures that are difficult to achieve in traditional casting processes by dividing the sand core of the double-suction pump impeller casting into multiple modules and 3D printing each module separately. By incorporating a reinforced core head, a support frame, a riser system, a connecting main beam, a split-type core cover, and a positioning structure, the strength, assembly accuracy, and casting quality of the sand core structure are effectively improved. This invention is simple to operate, has high forming accuracy, and is suitable for the efficient and high-quality manufacturing of complex structural castings.

[0049] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for forming a double-suction pump impeller based on 3D printing, characterized in that, The sand core of the double-suction pump impeller casting was divided into a bottom core, a lower impeller core, an upper impeller core, and a cover core, which were 3D printed separately. After 3D printing, the impeller was assembled and cast. The bottom of the bottom core is provided with an auxiliary core groove, and the auxiliary core groove is also inlaid with a gating auxiliary core. Reinforcing cores are provided on both sides of the lower impeller core and the upper impeller core, respectively; The bottom core, the lower impeller core, the upper impeller core, and the cover core are stacked sequentially.

2. The method for forming a dual-suction pump impeller based on 3D printing according to claim 1, characterized in that, A suspension hanger is provided on the outer end face of the reinforcing core head of the lower impeller core and the upper impeller core.

3. The method for forming a dual-suction pump impeller based on 3D printing according to claim 1, characterized in that, include: The upper part of the cover core is provided with an annular open riser; A heating riser is provided at the intermediate shaft hole of the double-suction pump impeller; Multiple concealed inclined risers are provided at the junction of the lower impeller core and the bottom core.

4. The method for forming a dual-suction pump impeller based on 3D printing according to claim 3, characterized in that, include: Each of the aforementioned oblique risers is provided with an inner gate below it, and the pouring is performed using the bisection method.

5. The method for forming a dual-suction pump impeller based on 3D printing according to claim 1, characterized in that, Also includes: A first connecting main beam is provided at the bottom of the lower impeller core, and a second connecting main beam is provided at the top of the upper impeller core.

6. The method for forming a dual-suction pump impeller based on 3D printing according to claim 5, characterized in that, The cover core is divided into two parts, which are respectively placed on both sides of the second connecting main beam of the upper impeller core.

7. The method for forming a dual-suction pump impeller based on 3D printing according to claim 1, characterized in that, include: Corresponding positioning holes and positioning posts are respectively provided between the bottom core and the lower impeller core, between the lower impeller core and the upper impeller core, and between the upper impeller core and the cover core.

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