Front mold core and end cover impeller mold of cross-flow fan blade

Abstract

The utility model relates to the field of cross-flow fan blade manufacturing, in particular to a front mold core and an end cover impeller mold of a cross-flow fan blade, the front mold core comprises an upper end face serving as the inner wall of an injection molding cavity, and an injection molding opening penetrating through the upper end face and the lower end face of the front mold core and used for being communicated with the injection molding cavity is formed in the front mold core; the injection molding opening is formed in the center area of the front mold core, a groove communicated with the injection molding opening is formed in the lower end face of the front mold core, and the injection molding opening is located at the bottom of the groove; a hot nozzle for injecting an injection molding material is embedded in the groove, and a discharge hole of the hot nozzle is communicated with the injection molding hole; a cooling channel surrounding the groove is further formed in the lower end face of the front mold core. The scheme has the advantages of improving the position design of the hot nozzle, reducing the phenomena of shrinkage and tension crack, and improving the product quality and the structural strength.

Description

Technical Field

[0001] This utility model relates to the field of cross-flow fan blade manufacturing, and in particular to a front mold core and an end cap impeller mold for cross-flow fan blades. Background Technology

[0002] In the manufacturing process of cross-flow fan rotors, the end cap impeller is a key component. End cap impellers are typically produced using a hot runner injection molding process, with the injection mold consisting of a front mold assembly and a rear mold assembly. During injection molding, the bushing assembly is first placed in the injection cavity between the front and rear mold assemblies, and then the end cap impeller is formed between the front and rear mold assemblies.

[0003] The overall structure of a cross-flow wind turbine includes end cap impellers, a steel shaft impeller, and several intermediate impellers. During production, the steel shaft impellers, intermediate impellers, and end cap impellers are sequentially welded using an ultrasonic welding machine to ultimately form a long, cylindrical cross-flow wind turbine. This structural design and manufacturing process ensures the overall performance and stability of the cross-flow wind turbine.

[0004] However, existing hot runner mold cores have some technical problems. The main issue lies in the unreasonable design of the hot nozzle's position, which is too close to the blade. This design causes shrinkage at the rubber impeller inlet during the injection process due to excessively high temperatures. More seriously, the blades may crack. These problems not only affect the product's appearance quality but may also reduce the structural strength and service life of the end cap impeller.

[0005] Furthermore, existing front mold core designs may not adequately consider heat distribution and heat dissipation. Uneven temperature distribution can lead to increased internal stress in injection molded products, thereby affecting dimensional accuracy and performance. Ineffective cooling can also prolong production cycles and reduce production efficiency.

[0006] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0007] To address the aforementioned problems, the primary objective of this invention is to provide a front mold core that offers advantages such as improved hot runner positioning, reduced shrinkage and tearing, and enhanced product quality and structural strength.

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

[0009] A front mold core, the technical solution of which is as follows: The front mold core includes an upper end face that serves as the inner wall of an injection cavity; an injection port is constructed on the front mold core, penetrating its upper and lower end faces for communication with the injection cavity; the injection port is constructed in the central region of the front mold core; a groove communicating with the injection port is constructed on the lower end face of the front mold core, and the injection port is located at the bottom of the groove; a hot nozzle for injecting injection material is embedded in the groove, and the outlet of the hot nozzle communicates with the injection port; a cooling channel is also constructed on the lower end face of the front mold core surrounding the groove.

[0010] Furthermore, this application also proposes that the inlet and outlet of the cooling channel are located on the side wall of the front mold core.

[0011] Furthermore, this application also proposes that a positioning groove for inserting a bushing assembly is constructed at the center of the upper end face of the front mold core, and a retaining ring surrounds the edge of the positioning groove; the injection port and its connected groove are provided in two sets, and the two sets of grooves are radially symmetrically arranged on the front mold core outside the retaining ring.

[0012] Furthermore, this application also proposes that an "8"-shaped annular area is constructed on the lower end surface of the front mold core, and two sets of grooves are disposed at both ends of the "8"-shaped annular area; the cooling channel is disposed around the "8"-shaped annular area.

[0013] Furthermore, this application also proposes that the figure-eight annular area is located within a circle of R43cm centered on the previous mold core, the distance between the injection ports corresponding to the two sets of grooves is 49cm, and the diameter of the hot nozzle is 20cm.

[0014] Furthermore, this application also proposes that two first extension arms are constructed at both ends of the figure-eight annular region, and the two first extension arms on the same side are symmetrically arranged on both sides of the central axis of the figure-eight annular region; two second extension arms are also constructed on the inner wall of the front mold core, facing the center of the figure-eight annular region, and the two second extension arms are symmetrically arranged on both sides of the central axis of the figure-eight annular region; the cooling channel is arranged in a circuitous manner around the first extension arms and the second extension arms from the liquid inlet to the liquid outlet.

[0015] Furthermore, this application also proposes that the discharge end of the hot nozzle is conical.

[0016] The second objective of this utility model is to provide an end cap impeller mold for a cross-flow fan blade, including a front mold assembly and a rear mold assembly; when the mold is closed, the front mold core of the front mold assembly and the rear mold core of the rear mold assembly are combined to form an injection cavity for injection molding the fan blade; the front mold core is the aforementioned front mold core.

[0017] Furthermore, this application also proposes that a piston is movably disposed in the runner plate of the front mold assembly, and a piston rod is connected to the piston; the injection port is located in the axial direction of the piston rod, and the movement of the piston along the piston chamber can drive the end of the piston rod to open or close the injection port.

[0018] Furthermore, this application also proposes that the rear mold core of the rear mold assembly is provided with an inner cooling channel and an outer cooling channel.

[0019] As described above, this application provides a front mold core and an end cap impeller mold for a cross-flow fan. The front mold core includes an upper end face that serves as the inner wall of an injection cavity. An injection port, penetrating both the upper and lower end faces of the front mold core and communicating with the injection cavity, is constructed on the front mold core. The injection port is located in the central region of the front mold core. A groove communicating with the injection port is constructed on the lower end face of the front mold core, with the injection port located at the bottom of the groove. A hot nozzle for injecting injection material is embedded in the groove, and the outlet of the hot nozzle communicates with the injection port. A cooling channel is also constructed on the lower end face of the front mold core, surrounding the groove. By optimizing the hot nozzle position design and increasing the cooling channel, heat distribution is effectively improved, shrinkage and cracking are reduced, thereby improving product quality and structural strength. Attached Figure Description

[0020] Figure 1 A schematic diagram of the upper end face of the front mold core provided in this application.

[0021] Figure 2 A schematic diagram of the lower end face of the front mold core provided in this application.

[0022] Figure 3 A schematic diagram of the hot nozzle structure provided in this application.

[0023] Figure 4 This is a schematic diagram of the end cap impeller mold for a cross-flow fan blade.

[0024] Figure 5 A schematic diagram of the lower end face of the rear mold core provided in this application. Detailed Implementation

[0025] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0026] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", 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 element 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.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0028] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. Example

[0030] like Figures 1-3As shown in Figure 4, this application proposes a front mold core 1, which includes an upper end face 11 serving as the inner wall of an injection cavity. An injection port 12, penetrating the upper and lower end faces of the front mold core 1 and communicating with the injection cavity, is constructed on the front mold core 1. The injection port 12 is located in the central region of the front mold core 1. A groove 14 communicating with the injection port 12 is constructed on the lower end face 13 of the front mold core 1, with the injection port 12 located at the bottom of the groove 14. A hot nozzle 3 for injecting injection material is embedded within the groove 14, and the outlet of the hot nozzle 3 communicates with the injection port 12. A cooling channel 10 is also constructed on the lower end face 13 of the front mold core 1, surrounding the groove 14. In this design, the injection port 12 is located in the central region of the front mold core 1, ensuring that the injection material can be evenly distributed within the central region of the injection cavity. Specifically, by placing the injection port 12 in the central area and cooperating with the groove 14 and the hot nozzle 3, which is located away from the blades of the end cap impeller (the blades of the end cap impeller are at the edge), the water-cooling area of ​​the front mold core 1 is increased, the mold temperature at the connection between the shaft cover impeller and the blades is reduced, production efficiency is improved, and product tearing is reduced. Furthermore, the cooling channel 10 surrounding the groove 14 effectively improves cooling efficiency, preventing material shrinkage or tearing caused by excessive temperature during injection molding. This design not only optimizes the distribution of injection material but also improves the cooling effect of the mold, thus solving the problems of uneven material distribution and poor cooling effect during injection molding. Therefore, the technical solution of this application effectively solves the technical problem of uneven material distribution and poor cooling effect caused by the unreasonable position of the injection port 12 during injection molding of the front mold core 1 by optimizing the position of the injection port 12 and the design of the cooling channel 10. Compared with the prior art, the technical solution of this application has higher production efficiency and better product quality.

[0031] Furthermore, the inlet and outlet of the cooling channel 10 are located on the side wall of the front mold core 1. Specific implementations of this design include, but are not limited to: the inlet and outlet can be located on the left and right sides of the front mold core 1 respectively, ensuring that coolant flows in from one side of the front mold core 1, passes through the mold core, and flows out from the other side, forming an effective cooling cycle. In addition, the positions of the inlet and outlet can be adjusted according to the specific shape and size of the mold core to ensure that the coolant can evenly cover the entire interior of the mold core, thereby improving cooling efficiency. The placement of the inlet and outlet of the cooling channel 10 on the side wall of the front mold core 1 helps the coolant flow more evenly through the mold core, thus improving cooling efficiency. By placing the inlet and outlet on the side wall, mold closing is not affected, and it ensures that the coolant forms an effective circulation within the mold core, avoiding localized overheating and reducing potential defects during injection molding, such as shrinkage and cracking. Compared with existing technologies, this design not only improves cooling performance but also simplifies the mold structure and reduces production costs.

[0032] like Figure 1 and 4 As shown, a positioning groove 15 for mounting the bushing assembly 2 is constructed at the center of the upper end face 11 of the front mold core 1. The bushing assembly 2 can be referenced from the workpiece described in the prior patent with publication number "CN213529700U". A retaining ring 151 surrounds the edge of the positioning groove 15; two sets of grooves 14 are provided for the injection port 12 and its connected grooves 14, which are radially symmetrically arranged on the front mold core 1 outside the retaining ring 151. The positioning groove 15 can be specifically implemented by machining a groove 14 at the center of the upper end face 11 of the front mold core 1 that matches the shape of the bushing assembly 2, ensuring that the bushing assembly 2 can be accurately embedded. The retaining ring 151 can be implemented by setting a raised annular structure around the edge of the positioning groove 15. The height and width of the retaining ring 151 can be adjusted according to the size of the bushing assembly 2 to ensure the stability of the bushing assembly 2 during the injection molding process. The injection port 12 and its connected groove 14 can be achieved by machining two sets of symmetrically distributed channels on the front mold core 1. The shape and size of the channels can be optimized according to the flow characteristics of the injection material to ensure that the injection material can flow evenly into the injection cavity. Furthermore, the depth and diameter of the positioning groove 15 can be precisely designed according to the dimensions of the bushing assembly 2 to ensure that the bushing assembly 2 does not shift or tilt during injection. The height of the retaining ring 151 can be slightly higher than the metal sheet of the bushing assembly 2 to ensure that the metal sheet can be stably mounted on the retaining ring 151, thereby preventing shaking during injection. The symmetrical distribution of the injection port 12 and its connected groove 14 can be achieved by setting two identical sets of channels on the front mold core 1. The inlet and outlet positions of the channels can be optimized according to the structure of the injection cavity to ensure that the injection material can be evenly distributed. Therefore, the technical solution of this application ensures the precise positioning and stability of the bushing assembly 2 during injection by constructing the positioning groove 15 and the retaining ring 151 at the center of the upper end face 11 of the front mold core 1. Meanwhile, by setting two sets of radially symmetrical injection ports 12 and their connected grooves 14, it is ensured that the injection material can flow evenly into the injection cavity, reducing molding defects caused by uneven injection. Compared with the prior art, the technical solution of this application can effectively improve the injection molding quality and reduce the occurrence of injection defects, and has significant practicality and innovation.

[0033] like Figure 2As shown, an "8"-shaped annular region 16 is formed on the lower end face 13 of the front mold core 1, with two sets of grooves 14 located at both ends of the "8"-shaped annular region 16; a cooling channel 10 is arranged around the "8"-shaped annular region 16. The "8"-shaped annular region 16 refers to the area with two annular portions formed on the lower end face 13 of the front mold core 1, resembling the shape of the number "8". The two sets of grooves 14 are located at both ends of the "8"-shaped annular region 16, and are used to accommodate the hot runner 3. The outlet of the hot runner 3 communicates with the injection port 12, thereby realizing the injection of molding material. The cooling channel 10 is arranged around the "8"-shaped annular region 16, with the inlet and outlet of the cooling channel 10 located on the side wall of the front mold core 1. Coolant flows through the cooling channel 10 to achieve uniform cooling of the injection area. Specifically, the shape of the "8"-shaped annular region 16 allows the two sets of grooves 14 to be symmetrically arranged at both ends of the region, which helps to achieve uniform distribution of the injection material within the mold cavity. Meanwhile, the cooling channel 10 is arranged around the figure-eight annular area 16. The shape of the figure-eight annular area 16 is concave in the middle, allowing the cooling channel 10 to flow as far as possible through the center of the front mold core 1. This ensures that the cooling effect can evenly cover the entire injection molding area, thereby effectively controlling the temperature during the injection molding process and preventing defects caused by overheating or uneven cooling of the material. Therefore, the technical solution of this application, by constructing a figure-eight annular area 16 on the lower end face 13 of the front mold core 1 and setting grooves 14 at both ends of this area, and simultaneously arranging the cooling channel 10 around the figure-eight annular area 16, achieves uniform distribution and effective cooling of the injection molding material. Compared with the prior art, the technical solution of this application can effectively avoid shrinkage at the rubber impeller inlet position and blade cracking caused by excessive temperature, improving the quality and production efficiency of injection molded products.

[0034] Furthermore, this application proposes that the figure-eight annular region 16 of the front mold core 1 is located within a radius of R43cm centered on the front mold core 1, the distance between the injection ports 12 corresponding to the two sets of grooves 14 is 49cm, and the diameter of the hot runner 3 is 20cm. This scheme is applicable to impellers with an injection radius ranging from 49cm to 61cm. Precise control of these dimensions helps optimize heat conduction and material flow during the injection molding process, thereby reducing problems of uneven temperature and poor material flow. Specifically, the figure-eight annular region 16 of the front mold core 1 is located in the central area of ​​the front mold core 1, ensuring uniform distribution and flow of the injection material within the mold cavity. By setting the distance between the injection ports 12 of the two sets of grooves 14 to 49cm, and the diameter of the hot runner 3 to 20cm, and controlling the inner edges of the water channel of the front mold core 1 within R43cm, precise control of these dimensions helps optimize heat conduction and material flow during the injection molding process, thereby reducing problems of uneven temperature and poor material flow. This design ensures the stability of the injection molding process and the consistency of product quality by precisely controlling key dimensions. Therefore, the technical solution of this application effectively solves the technical problems of uneven temperature distribution and poor material flow that may occur in the front mold core 1 during injection molding by precisely controlling the size and layout of the figure-eight annular region 16 and its related structures. Compared with the prior art, the technical solution of this application significantly improves the stability of the injection molding process and the consistency of product quality by optimizing heat conduction and material flow paths.

[0035] like Figure 2 As shown, two first extension arms 171 are constructed at both ends of the figure-eight annular region 16, with the two first extension arms 171 on the same side symmetrically arranged on both sides of the central axis of the figure-eight annular region 16; two second extension arms 172 are also constructed on the inner wall of the front mold core 1, facing the center of the figure-eight annular region 16, with the two second extension arms 172 symmetrically arranged on both sides of the central axis of the figure-eight annular region 16; the cooling channel 10 is arranged in a meandering manner around the first extension arms 171 and the second extension arms 172 from the liquid inlet to the liquid outlet, and the cooling channel 10 is specifically arranged along the attached Figure 2The dotted lines in the diagram illustrate this design. The design of the first extension arm 171 and the second extension arm 172 allows the cooling channel 10 to form a complex, meandering path within the front mold core 1. This path not only increases the total length of the cooling channel 10 but also improves the contact area between the coolant and the inner wall of the mold core. For example, the first extension arm 171 can be designed as a straight line or a curve to adapt to different cooling requirements; the second extension arm 172 can be designed as an arc extending towards the center area to enhance the cooling effect. Therefore, the technical solution of this application significantly improves cooling efficiency and ensures uniform distribution of the injection molding material by optimizing the layout of the cooling channel 10. Compared with the prior art, this solution effectively avoids deformation or quality problems of the injection molded parts caused by uneven cooling by increasing the length and coverage area of ​​the cooling channel 10. Specifically, the meandering arrangement of the cooling channel 10 not only extends the flow path of the coolant but also ensures uniform distribution of the coolant within the mold core through the symmetrical arrangement of the first extension arm 171 and the second extension arm 172, thereby achieving uniform cooling and solidification of the injection molding material.

[0036] like Figure 3 As shown, the ejector end of the hot runner 3 is tapered. This design helps improve the flow characteristics of the injection molding material during ejection, reduces resistance during material flow, and improves the uniform distribution of the injection molding material, thereby improving the molding quality and surface finish of the injection molded product. The tapered design also reduces the residence time of the material at the ejector, reducing the risk of material degradation due to overheating, further ensuring product quality. The tapered ejector end design can be achieved in several ways. For example, the tapered angle can be adjusted according to the flowability of the injection molding material and the specific requirements of the mold to achieve the best flow effect. In addition, the surface of the tapered ejector end can be specially treated, such as polishing or coating, to reduce frictional resistance during material flow. Example

[0037] like Figure 4 and 5As shown, this application also proposes an end cap impeller mold for a cross-flow fan blade, including a front mold assembly 100 and a rear mold assembly 400. During mold closing, the front mold core 1 of the front mold assembly 100 and the rear mold core 4 of the rear mold assembly 400 combine to form an injection cavity 40 for injection molding the fan blade. The front mold core 1 of the front mold assembly 100 adopts the front mold core 1 described in Example 1. The design of the front mold core 1 includes features such as an injection port 12, a groove 14, a hot nozzle 3, and a cooling channel 10. These features work together to ensure that the injection material can be injected into the injection cavity 40 uniformly and stably. Simultaneously, the cooling channel 10 effectively controls the mold temperature, preventing shrinkage or cracking during the injection process. Therefore, the technical solution of this application, by designing the front mold core 1 with the above-mentioned features, ensures that the structure and function of the front mold core 1 can meet the accuracy and stability requirements of the injection cavity 40. Through this design, the technical solution of this application effectively solves the problems of precision and stability of the injection cavity 40 in the end cap impeller mold of the cross-flow fan. Compared with the prior art, the technical solution of this application optimizes the structure of the front mold core 1, realizes uniform injection of injection material and effective control of mold temperature, thereby avoiding shrinkage or cracking that may occur during injection molding, and improving the quality and production efficiency of injection molded products.

[0038] Furthermore, a piston 181 is movably disposed in the runner plate of the front mold assembly 100, and a piston rod 182 is connected to the piston 181. The injection port 12 is located in the axial direction of the piston rod 182. The movement of the piston 181 along the piston chamber can drive the end of the piston rod 182 to open or close the injection port 12. Specifically, the piston 181 can be driven by hydraulic or pneumatic pressure to reciprocate within the piston chamber. One end of the piston rod 182 is fixedly connected to the piston 181, and the other end extends to the vicinity of the injection port 12. When the piston 181 moves along the piston chamber, the end of the piston rod 182 moves accordingly, thereby opening or closing the injection port 12. As a preferred embodiment, the movement of the piston 181 can be controlled by a solenoid valve to achieve precise opening and closing of the injection port 12. In addition, the end of the piston rod 182 can be designed as conical or spherical to better adapt to the shape of the injection port 12 and ensure a sealing effect. Therefore, the technical solution of this application achieves flexible control of the injection port 12 by setting a piston 181 and a piston rod 182 in the runner plate of the front mold assembly 100. When the piston 181 moves along the piston chamber, it drives the end of the piston rod 182 to open or close the injection port 12, thereby solving the problem of the injection port 12 being unable to be flexibly controlled during the injection process. This design makes the injection process more precise and controllable, preventing injection material from flowing into the injection cavity 40 when not needed, and improving injection quality and production efficiency. Compared with the prior art, the technical solution of this application has higher flexibility and precision, and can effectively avoid injection material waste and product quality problems.

[0039] like Figure 5 As shown, the rear mold core 4 of the rear mold assembly 400 is provided with an inner cooling channel 41 and an outer cooling channel 42. The inner cooling channel 41 is mainly responsible for cooling the inside of the mold core, while the outer cooling channel 42 is responsible for cooling the outside of the mold core. The two work together to ensure that the entire rear mold core 4 can be cooled evenly during the injection molding process, avoiding deformation or quality degradation of the injection molded part due to uneven cooling. Specifically, the inner cooling channel 41 can be designed as a spiral or serpentine shape to increase the flow path of the coolant inside the mold core, thereby improving cooling efficiency. The outer cooling channel 42 can be arranged around the outer periphery of the mold core to form an annular or multi-segment cooling channel 10 to ensure uniform cooling of the outside of the mold core. In addition, the cross-sectional shape of the cooling channel can be designed as a circle, ellipse, or other suitable shape to adapt to different cooling requirements. Thus, the technical solution of this application, by setting the inner cooling channel 41 and the outer cooling channel 42, achieves uniform cooling of the rear mold core 4, effectively solving the problem of uneven cooling of the rear mold core 4 in the prior art. Compared with the prior art, the technical solution of this application not only improves the quality of injection molded parts, but also reduces the deformation and defects of injection molded parts caused by uneven cooling, and has significant practicality and innovation.

[0040] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example 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.

[0041] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A front mold core, the front mold core (1) comprising an upper end face (11) as an inner wall of an injection molding cavity (40), the front mold core (1) being provided with an injection port (12) penetrating through the upper and lower end faces (13) thereof for communicating with the injection molding cavity (40); characterized in that: The injection port (12) is constructed in the central region of the front mold core (1), a recess (14) communicating with the injection port (12) is constructed on the lower end surface (13) of the front mold core (1), and the injection port (12) is located at the bottom of the recess (14); a hot nozzle (3) for injecting injection material is embedded in the recess (14), and the discharge port of the hot nozzle (3) communicates with the injection port (12); the lower end surface (13) of the front mold core (1) is also constructed with a cooling channel (10) arranged around the recess (14).

2. A front mold core according to claim 1, characterized in that: The inlet and outlet of the cooling channel (10) are arranged on the side wall of the front mold core (1).

3. A front mold core according to claim 1, wherein: A positioning groove (15) for embedding the bushing assembly (2) is constructed at the center of the upper end surface (11) of the front mold core (1), and a retaining ring (151) is enclosed around the edge of the positioning groove (15); the injection port (12) and the recess (14) communicating therewith are provided with two groups, and the two groups of recesses (14) are radially symmetrically arranged on the outside of the front mold core (1) of the retaining ring (151).

4. A front mold core according to claim 3, wherein: An "8" shaped annular region (16) is constructed on the lower end surface (13) of the front mold core (1), and the two groups of recesses (14) are arranged at the two ends of the "8" shaped annular region (16); the cooling channel (10) is arranged around the "8" shaped annular region (16).

5. A front mold core according to claim 4, wherein: The "8" shaped annular region (16) is within the center range of a circle with a radius of 43 cm centered on the front mold core (1), the distance between the injection ports (12) corresponding to the two groups of recesses (14) is 49 cm, and the diameter of the hot nozzle (3) is 20 cm.

6. A front mold core according to claim 4, wherein: Two first extension arms (171) are constructed at the two ends of the "8" shaped annular region (16), and the two first extension arms (171) on the same side are symmetrically arranged on both sides of the central axis of the "8" shaped annular region (16); two second extension arms (172) are also constructed on the inner wall of the front mold core (1) and face the center of the "8" shaped annular region (16), and the two second extension arms (172) are symmetrically arranged on both sides of the central axis of the "8" shaped annular region (16); the cooling channel (10) is arranged around the first extension arm (171) and the second extension arm (172) from the inlet to the outlet.

7. A front mold core according to claim 1, wherein: The discharge end of the hot nozzle (3) is conical.

8. An end cover impeller mold for a cross-flow fan blade, comprising a front mold assembly (100) and a rear mold assembly (400); when the mold is closed, a front mold core (1) of the front mold assembly (100) and a rear mold core (4) of the rear mold assembly (400) combine to form an injection molding cavity (40) for injection molding a fan wheel; characterized in that: The front mold core (1) is the front mold core (1) according to any one of claims 1-7.

9. A tube blade end cover impeller mold according to claim 8, characterized in that: A piston (181) is movably arranged in the flow channel plate of the front mold assembly (100), and a piston rod (182) is connected to the piston (181); the injection port (12) is in the axial direction of the piston rod (182), and the movement of the piston (181) along the piston chamber can drive the end of the piston rod (182) to open or close the injection port (12).

10. A tube blade end cover impeller mold according to claim 8, characterized in that: The rear mold core (4) of the rear mold assembly (400) is provided with an inner cooling channel (41) and an outer cooling channel (42).

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