3D printing sand core for casting double-suction impeller of centrifugal pump

Abstract

The utility model provides a kind of 3D printing sand core for centrifugal pump double-suction impeller casting, the utility model includes 3D printing sand core assembly, the sand core solidity of the sand core of the front cover plate side sand core, front cover plate side blade sand core, shaft hole sand core, rear cover plate side blade sand core and rear cover plate side sand core is high, strength is uniform, sand core quality has been greatly promoted, compared with traditional wood mould, can not be set draft angle, shaft hole sand core exhaust hole is convenient for the discharge of gas produced by resin combustion in pouring process, avoid the gas hole defect of casting, casting tie bar guarantees the accuracy of the outlet size of double-suction impeller body after casting, positioning core head A is connected with front cover plate side blade sand core, rear cover plate side blade sand core is connected with rear cover plate side sand core by positioning core head C, shaft hole sand core is inserted into axial hollow part, is fixed by positioning core head B, three-point cylindrical positioning boss is pressed into three-point cylindrical positioning concave, complete radial locking and guarantee the position degree and the accuracy of size when box is closed, production error is smaller, production quality is improved.

Description

Technical Field

[0001] This utility model relates to the field of 3D printing sand core technology, and in particular to a 3D printing sand core for casting a centrifugal pump double-suction impeller. Background Technology

[0002] The impeller is a key component of a centrifugal pump. It consists of a front cover plate, a rear cover plate, a hub, and several curved blades. The main function of the impeller is to directly transfer the mechanical energy of the prime mover to the liquid to increase the static pressure energy and dynamic pressure energy of the liquid. According to the structure, it can be divided into three types: closed impeller, semi-closed impeller, and open impeller.

[0003] According to the suction method, impellers can be divided into single-suction impellers and double-suction impellers. Single-suction impellers have a simple structure, with liquid being drawn in from only one side. This type of impeller is commonly used in small-flow water pumps. Double-suction impellers have a more complex structure, with liquid being drawn in from both sides. They have a larger suction capacity and are commonly used in large-flow water pumps. The blades of centrifugal water pump impellers are generally backward-curved blades with a spatially twisted shape. This spatial twisting reduces the load on the blades and improves the suction performance of the centrifugal pump, as well as enhancing its cavitation resistance.

[0004] Currently, in traditional sand casting processes, sand cores are made using wooden molds, which are then handcrafted. Due to inherent deviations in the production of wooden molds, coupled with operational errors during manual sand mold making and the draft angles of the molds themselves, the actual produced products often deviate significantly from the design drawings. This results in generally poor production quality and severely impacts the impeller's performance parameters.

[0005] Therefore, it is essential to provide a 3D-printed sand core for casting a double-suction impeller of a centrifugal pump to address the shortcomings of existing technologies. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies by providing a 3D-printed sand core for casting a double-suction impeller for a centrifugal pump. This ensures the accuracy of the dimensions of the hydraulic parts of the double-suction impeller and meets the internal quality requirements during actual production. Moreover, this invention is simple to operate, highly adaptable, cost-effective, improves production efficiency, and shortens the production cycle.

[0007] The above-mentioned objectives of this utility model are achieved through the following technical means.

[0008] A 3D-printed sand core for casting a centrifugal pump double-suction impeller is provided, including a double-suction impeller body, and a 3D-printed sand core assembly is disposed on the outside of the double-suction impeller body. The 3D-printed sand core assembly includes a front cover plate side sand core, a front cover plate side blade sand core, a shaft hole sand core, a rear cover plate side blade sand core, and a rear cover plate side sand core.

[0009] Specifically, the front cover plate side sand core, the front cover plate side blade sand core, the rear cover plate side blade sand core, and the rear cover plate side sand core are sequentially interlocked, and the axially hollowed-out parts are interlocked with the shaft hole sand core. All five sand cores are made by printing with a sand mold 3D printer, and their processing accuracy can be controlled within 0.3mm. The fit gap between the five sand molds is controlled within a very small gap of 0.3mm on each side, ensuring the assembly accuracy of the 3D printed sand core components.

[0010] Preferably, a positioning head A is installed between the front cover plate side sand core and the front cover plate side blade sand core, a positioning head B is installed between the rear cover plate side blade sand core and the shaft hole sand core, a positioning head C is installed between the rear cover plate side sand core and the rear cover plate side blade sand core, and several exhaust channels with a diameter of 5mm are respectively opened on the outer side of the front cover plate side blade sand core and the rear cover plate side blade sand core.

[0011] A 20mm diameter vent hole is provided at the center of the shaft hole sand core. A frustum positioning assembly is installed between each pair of the front cover plate side sand core, the front cover plate side blade sand core, the rear cover plate side blade sand core, and the rear cover plate side sand core. Three arc-shaped riser necks are provided at equal angles on the inner side of the front cover plate side sand core. Hidden riser necks are provided symmetrically on both sides of the rear cover plate side sand core. A 10mm×8mm rectangular cross-section casting tie is installed between each pair of blades on the front cover plate side blade sand core and the rear cover plate side blade sand core corresponding to the double suction impeller body.

[0012] Each set of truncated cone positioning components includes a three-point cylindrical positioning boss and a three-point cylindrical positioning recess. The three-point cylindrical positioning boss and the three-point cylindrical positioning recess are connected in a three-point structure.

[0013] Three three-point cylindrical positioning bosses are respectively installed on the lower end faces of the front cover plate side sand core, the front cover plate side blade sand core, and the rear cover plate side blade sand core, and three cylindrical positioning recesses are respectively installed on the upper end faces of the front cover plate side blade sand core, the rear cover plate side blade sand core, and the rear cover plate side sand core.

[0014] Lifting cylinders are symmetrically installed on both sides of the front cover plate side sand core, the front cover plate side blade sand core, the rear cover plate side blade sand core, and the rear cover plate side sand core.

[0015] In this invention, the positioning core A connects to the front cover plate side blade sand core, and the rear cover plate side blade sand core connects to the rear cover plate side sand core via the positioning core C. The shaft hole sand core is inserted into the axial hollowed-out area and fixed by the positioning core B. The three-point cylindrical positioning boss is pressed into the three-point cylindrical positioning recess, completing the radial locking and ensuring the positional and dimensional accuracy when the box is closed. The production error is small, and the production quality is improved. Attached Figure Description

[0016] The present invention will be further described with reference to the accompanying drawings, but the content of the drawings does not constitute any limitation on the present invention.

[0017] Figure 1 This is a disassembled view of the overall structure of a 3D-printed sand core for casting a double-suction impeller of a centrifugal pump, according to this utility model.

[0018] Figure 2 This is a cross-sectional view of the overall structure of a 3D-printed sand core for casting a double-suction impeller of a centrifugal pump according to this utility model.

[0019] Figure 3 This is a schematic diagram of the front cover plate side sand core structure of a 3D printed sand core for casting a centrifugal pump double-suction impeller according to the present invention.

[0020] Figure 4 This is a schematic diagram of the front cover plate side blade sand core structure of a 3D printed sand core for casting a centrifugal pump double-suction impeller according to the present invention.

[0021] Figure 5 This is a schematic diagram of the shaft hole sand core structure of a 3D printed sand core for casting a double-suction impeller of a centrifugal pump according to this utility model.

[0022] Figure 6 This is a schematic diagram of the rear cover plate side blade sand core structure of a 3D printed sand core for casting a centrifugal pump double-suction impeller according to the present invention.

[0023] Figure 7 This is a schematic diagram of the rear cover plate side sand core structure of a 3D printed sand core for casting a centrifugal pump double-suction impeller according to this utility model.

[0024] from Figures 1 to 7 Including:

[0025] 1. Double-suction impeller body;

[0026] 2. 3D printed sand core components;

[0027] 3. Front cover plate side sand core;

[0028] 4. Sand core of the side blades of the front cover plate;

[0029] 5. Shaft hole sand core;

[0030] 6. Sand core of the side blades of the rear cover plate;

[0031] 7. Rear cover plate side sand core;

[0032] 8. Positioning core A;

[0033] 9. Positioning core B;

[0034] 10. Positioning the core tip C;

[0035] 11. Exhaust duct;

[0036] 12. Shaft hole sand core vent hole;

[0037] 13. Frustum positioning component;

[0038] 14. Arched riser neck;

[0039] 15. Hidden mouth and neck;

[0040] 16. Cast tie rods;

[0041] 17. Three-point cylindrical positioning boss;

[0042] 18. Three-point cylindrical positioning recess;

[0043] 19. Lifting of cylindrical columns. Detailed Implementation

[0044] The present invention will be further described in conjunction with the following embodiments.

[0045] Example 1.

[0046] like Figure 1-7 As shown, a 3D-printed sand core for casting a centrifugal pump double-suction impeller includes a double-suction impeller body 1, and a 3D-printed sand core assembly 2 is disposed on the outside of the double-suction impeller body 1. The 3D-printed sand core assembly 2 includes a front cover plate side sand core 3, a front cover plate side blade sand core 4, a shaft hole sand core 5, a rear cover plate side blade sand core 6, and a rear cover plate side sand core 7.

[0047] like Figure 1-7 As shown, the front cover plate side sand core 3, the front cover plate side blade sand core 4, the rear cover plate side blade sand core 6, and the rear cover plate side sand core 7 are sequentially interlocked, and the shaft hole sand core 5 is interlocked at the axially hollowed-out part. All five sand cores are made by printing with a sand mold 3D printer. At the same time, the molding sand is composed of sand particles with a diameter of 0.3mm that have been carefully screened. Compared with the 0.4-0.7mm molding sand used in traditional processes, the surface finish of the sand mold is higher, which in turn results in a higher finish of the hydraulic parts of the casting, greatly reducing the workload of grinding and polishing the hydraulic parts.

[0048] like Figure 1-7 As shown, the processing accuracy of the sand mold 3D printer can be controlled within 0.3mm. The mating gap between the five sand cores is controlled within a very small gap of 0.3mm on one side, ensuring the assembly accuracy of the 3D printed sand core component 2. In small-batch production, there is no need to make molds, saving mold costs and shortening the production cycle. In large-batch production, the consistency of sand mold size can be guaranteed, resulting in high production efficiency and less impact from human factors.

[0049] like Figure 1-7As shown, the sand core is printed by a sand mold 3D printer. Compared with the traditional wooden mold sand casting process, it completely solves the problems of wooden mold deviation and sand core size deviation caused by workers' casting. At the same time, the five sand cores have high compactness and uniform strength. The amount of resin curing agent added is reduced compared with the traditional sand mixing process, and the quality of the sand core is greatly improved. Compared with the traditional wooden mold, there is no need to set the draft angle, which reduces the weight of the product blank and the amount of machining work, saving costs.

[0050] like Figure 1-7 As shown, a positioning core A8 is installed between the front cover plate side sand core 3 and the front cover plate side blade sand core 4; a positioning core B9 is installed between the rear cover plate side blade sand core 6 and the shaft hole sand core 5; and a positioning core C10 is installed between the rear cover plate side sand core 7 and the rear cover plate side blade sand core 6. Several venting channels 11 with a diameter of 5mm are respectively opened on the outer side of the front cover plate side blade sand core 4 and the rear cover plate side blade sand core 6, which is conducive to the discharge of gases generated by resin combustion during the casting process and avoids porosity defects in the casting.

[0051] like Figure 1-7 As shown, a 20mm diameter shaft hole sand core vent 12 is provided at the center of the internal axis of the shaft hole sand core 5 to facilitate the discharge of gas generated by resin combustion during the pouring process and avoid porosity defects in the casting. A frustum positioning assembly 13 is installed between each pair of the front cover plate side sand core 3, the front cover plate side blade sand core 4, the rear cover plate side blade sand core 6, and the rear cover plate side sand core 7.

[0052] Three arc-shaped riser necks 14 are opened at equal angles on the inner side of the front cover plate side sand core 3, and hidden riser necks 15 are symmetrically opened on both sides of the rear cover plate side sand core 7. A 10mm×8mm rectangular cross-section casting tie rod 16 is installed between each two blades of the double suction impeller body 1 on the front cover plate side blade sand core 4 and the rear cover plate side blade sand core 6, ensuring the accuracy of the outlet size of the double suction impeller body 1 after casting.

[0053] like Figure 1-7 As shown, each set of frustum positioning components 13 includes a three-point cylindrical positioning boss 17 and a three-point cylindrical positioning recess 18. The three-point cylindrical positioning boss 17 and the three-point cylindrical positioning recess 18 are engaged by three frustums of different sizes and asymmetrically distributed inside the circular slot. The three-point cylindrical positioning boss 17 and the three-point cylindrical positioning recess 18 are engaged in a three-point structure, which ensures the accuracy of position and size when the box is closed.

[0054] like Figure 1-7As shown, three three-point cylindrical positioning bosses 17 are respectively installed on the lower end surfaces of the front cover plate side sand core 3, the front cover plate side blade sand core 4, and the rear cover plate side blade sand core 6, and three cylindrical positioning recesses are respectively installed on the upper end surfaces of the front cover plate side blade sand core 4, the rear cover plate side blade sand core 6, and the rear cover plate side sand core 7.

[0055] like Figure 1-7 As shown, hoisting columns 19 are symmetrically installed on both sides of the front cover plate side sand core 3, the front cover plate side blade sand core 4, the rear cover plate side blade sand core 6, and the rear cover plate side sand core 7.

[0056] This utility model includes a 3D printed sand core assembly 2. The 3D printed sand core assembly 2 comprises five sand cores: a front cover plate side sand core 3, a front cover plate side blade sand core 4, a shaft hole sand core 5, a rear cover plate side blade sand core 6, and a rear cover plate side sand core 7. These five sand cores have high compactness and uniform strength, significantly improving the quality of the sand cores. Compared to traditional wooden molds, draft angles are not required. The shaft hole sand core's vent hole 12 facilitates the discharge of gases generated during resin combustion during the casting process, preventing porosity defects in the casting. The casting tie rod 16 ensures the accuracy of the outlet size of the double-suction impeller body 1 after casting. The positioning core head A 8 connects to the front cover plate side blade sand core 4, and the rear cover plate side blade sand core 6 connects to the rear cover plate side sand core 7 via the positioning core head C 10. The shaft hole sand core 5 is inserted into the axially hollowed-out portion, and the positioning core head B connects to it. 9. The three-point cylindrical positioning boss 17 is pressed into the three-point cylindrical positioning recess 18 to complete the radial locking and ensure the positional and dimensional accuracy when closing the box. The production error is small and the production quality is improved.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit the scope of protection of this utility model. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the essence and scope of the technical solutions of this utility model.

Claims

1. A 3D-printed sand core for casting a double-suction impeller of a centrifugal pump, comprising a double-suction impeller body, characterized in that: The exterior of the dual-suction impeller body is provided with a 3D-printed sand core assembly. The 3D-printed sand core assembly includes a front cover plate side sand core, a front cover plate side blade sand core, a shaft hole sand core, a rear cover plate side blade sand core, and a rear cover plate side sand core. The front cover plate side sand core, the front cover plate side blade sand core, the rear cover plate side blade sand core, and the rear cover plate side sand core are sequentially snapped together, and the shaft hole sand core is snapped together at the axially hollowed-out part. A positioning core A is fitted between the front cover plate side sand core and the front cover plate side blade sand core. A positioning core B is fitted between the rear cover plate side blade sand core and the shaft hole sand core. A positioning core C is fitted between the rear cover plate side sand core and the rear cover plate side blade sand core. Several exhaust channels are opened on the front cover plate side blade sand core and the rear cover plate side blade sand core respectively. A shaft hole sand core exhaust hole is opened at the center of the internal axis of the shaft hole sand core. A frustum positioning assembly is installed between each pair of the front cover plate side sand core, the front cover plate side blade sand core, the rear cover plate side blade sand core, and the rear cover plate side sand core. Three arc-shaped riser necks are opened at equal angles on the inner side of the front cover plate side sand core. Hidden riser necks are symmetrically opened on both sides of the rear cover plate side sand core. Casting tie rods are installed between every two blades of the front cover plate side blade sand core and the rear cover plate side blade sand core corresponding to the double suction impeller body.

2. The 3D-printed sand core for casting a double-suction impeller of a centrifugal pump according to claim 1, characterized in that: Each set of the frustum positioning components includes a three-point cylindrical positioning boss and a three-point cylindrical positioning recess, wherein the three-point cylindrical positioning boss and the three-point cylindrical positioning recess are correspondingly engaged in a three-point structure.

3. The 3D-printed sand core for casting a double-suction impeller of a centrifugal pump according to claim 2, characterized in that: The three three-point cylindrical positioning bosses are respectively installed on the lower end surfaces of the front cover plate side sand core, the front cover plate side blade sand core, and the rear cover plate side blade sand core, and the three cylindrical positioning recesses are respectively installed on the upper end surfaces of the front cover plate side blade sand core, the rear cover plate side blade sand core, and the rear cover plate side sand core.

4. The 3D-printed sand core for casting a double-suction impeller of a centrifugal pump according to claim 3, characterized in that: Lifting cylinders are symmetrically installed on both sides of the front cover plate side sand core, the front cover plate side blade sand core, the rear cover plate side blade sand core, and the rear cover plate side sand core.

Images