Impeller rotor injection molding device and method for electronic water pump

Abstract

The invention relates to an injection molding device and method for an impeller rotor of an electronic water pump. The injection molding device comprises an injection molding machine, a mold, an insert, a drying oven and a press tool. The mold is provided with a first mold and a second mold and is used for injection molding of a to-be-injection-molded part; in the injection molding process, the first mold and the second mold are controlled at the first temperature; the insert is detachably arranged on the second mold and is matched with the first mold, the second mold and a part to be subjected to injection molding on the first mold to form a cavity for injection molding after mold closing; in the injection molding process, the molding position of the cavity is controlled at a second temperature; after injection molding and mold opening, the insert is coaxially coated outside the impeller rotor after injection molding and is separated from the contact with the second mold; the drying oven is arranged beside the injection molding machine and is used for heating the insert; the press tool is arranged beside the injection molding machine and is used for separating the insert from the impeller rotor subjected to injection molding; the first temperature is lower than the second temperature.

Description

Technical Field

[0001] The invention relates to the technical field of impeller rotor injection molding, and in particular to an impeller rotor injection molding device and an injection molding method for an electronic water pump. Background Art

[0002] The impeller rotor, a component of the brushless electronic water pump, needs to be injected twice during the production process. The first injection molding needs to embed the aluminum iron boron magnet, and the second injection molding needs to wrap the aluminum iron boron magnet to prevent the magnet from rusting and cracking. At present, due to the technical bottleneck of injection molding production in the industry, most of them use PP (polypropylene) and POM (polyoxymethylene) materials for injection molding. With the rapid development of the dishwasher industry, in order to adapt to the complex working environment, the impeller rotor is required to have the characteristics of high and low temperature impact resistance and long life, while conventional PP and POM materials cannot meet the requirements of stable operation between -40 degrees and 120 degrees. Through testing, polyphenylene sulfide containing 40% glass fiber can meet the requirements of stable operation between -40 degrees and 120 degrees, but the gap between the aluminum iron boron magnet and the stator core is limited (after the impeller rotor is installed, the gap between the stator core is limited), so the thickness of the injection molding material wrapped in the outer layer of the aluminum iron boron magnet can only be 0.5-0.6mm. How to make the polyphenylene sulfide material containing 40% glass fiber maintain good fluidity in such a narrow space, so as to obtain a high degree of crystallization and a smooth product surface, is a major difficulty in the industry. Summary of the invention

[0003] The embodiment of the present invention provides an impeller rotor injection molding device and an injection molding method of an electronic water pump to solve the problems in the prior art.

[0004] The embodiment of the present invention adopts the following technical scheme: an impeller rotor injection molding device for an electronic water pump, comprising an injection molding machine, a mold, an insert, an oven and a press tooling, wherein: the mold is installed on the injection molding machine, and has a first mold and a second mold, which are used for injection molding of the part to be injected; during the injection molding process, the first mold and the second mold are controlled at a first temperature; the insert is detachably arranged on the second mold, and after the mold is closed, it cooperates with the first mold, the second mold, and the part to be injected placed on the first mold to form an injection molding cavity; during the injection molding process, the molding part of the cavity is controlled at a second temperature, so that the injection molding material can flow in the cavity with a gap of 0.5-0.6mm; after injection molding and mold opening, the insert is coaxially coated on the outside of the impeller rotor after injection molding, and is separated from the contact with the second mold; the oven is arranged next to the injection molding machine, and is used to heat the insert; the press tooling is arranged next to the injection molding machine, and is used to separate the insert and the impeller rotor after injection molding; the first temperature is lower than the second temperature.

[0005] Preferably, the first temperature is 120-160 degrees Celsius, and the second temperature is 170-190 degrees Celsius.

[0006] Preferably, there are at least two inserts, at least one of which is located in an oven for heating, and at least one is located in the mold for injection molding.

[0007] Preferably, the injection molding material is polyphenylene sulfide containing 40% glass fiber.

[0008] Preferably, the first mold includes: a first mold frame; a first mold core, which is arranged on the first mold frame; a first slider, which is slidably arranged on the first mold core; a slider core, which is connected to or integrally formed on the first slider; in the mold closing state, the slider core cooperates with the insert, the second mold, and the part to be injected placed on the first mold to form a cavity for injection molding.

[0009] Preferably, in the mold closing state after injection molding, the slider core is embedded in the annular groove of the impeller rotor neck after injection molding.

[0010] Preferably, the press tooling includes: a base; a positioning bracket, arranged on the base, for placing the inserts to be separated and the impeller rotor after injection molding; a guide column, arranged on the base; and a punch, slidably arranged on the guide column and capable of moving relative to the positioning bracket to separate the inserts and the impeller rotor after injection molding.

[0011] Preferably, the positioning bracket includes: a bracket body, which is arranged on the base; a first groove, which is located at the upper part of the bracket body; a second groove, which is located at the lower part of the bracket body; a limiting portion, which is located between the first groove and the second groove, so that a U-shaped narrow neck area is formed at the junction of the first groove and the second groove, and the width of the narrow neck area is larger than the inner diameter of the insert and smaller than the outer diameter of the insert; when the insert to be separated and the impeller rotor after injection molding are placed on the positioning bracket, the insert is coaxial with the punch, the impeller part of the impeller rotor is located in the second groove, the upper end face of the limiting portion is against the lower end face of the insert, and a gap is left between the end of the limiting portion and the bottom wall of the annular groove of the neck of the impeller rotor.

[0012] A method for injection molding an impeller rotor of an electronic water pump, using the injection molding device for injection molding, comprising: Turning on the injection molding machine, controlling the temperature of the first mold and the second mold to be at a first temperature, and placing the part to be injection molded in the first mold of the mold; Turn on the oven, place the insert in the oven for heating, and place the heated insert in the second mold of the mold so that the cavity molding part is controlled at the second temperature; The first mold and the second mold are closed so that the insert cooperates with the first mold, the second mold, and the part to be molded placed on the first mold to form a mold cavity for injection molding; injection molding is performed into the mold cavity so that the injection molding material can flow in the mold cavity with a gap of 0.5-0.6 mm; After the injection molding, the mold is opened so that the insert is coaxially wrapped around the impeller rotor after the injection molding and is out of contact with the second mold; The insert and the injection-molded impeller rotor are removed from the first mold, placed on a press tooling, and the insert and the injection-molded impeller rotor are separated.

[0013] Preferably, there are at least two inserts, at least one of which is placed in an oven for heating, and at least one is used for injection molding.

[0014] At least one of the above technical solutions adopted in the embodiments of the present invention can achieve the following beneficial effects: The insert is heated in an oven and then placed on the second mold. The heated insert is used as one of the components forming the injection molding cavity, so that the temperature of the molding location can be controlled at the second temperature. That is, the insert separable from the mold is used as one of the components forming the injection molding cavity and as a core component for controlling the temperature of the molding location. Even if the gap between the outer surface of the aluminum iron boron magnet and the inner wall of the insert is only 0.5-0.6mm, it can ensure that the injection molding material has a high fluidity, thereby obtaining a high degree of crystallization and a smooth product surface.

[0015] In addition, the heating system of the injection molding machine controls the temperature of the entire mold at the first temperature, and the temperature of the molding location is controlled by the insert at the second temperature, so as to achieve different temperatures in different parts. This can avoid the problem that the entire mold is maintained at a high temperature of the second temperature, resulting in the overall mold frame, guide pins and sleeves, and various transmission components being affected to varying degrees. It can also avoid the problem that the entire mold is maintained at the first temperature (the temperature of the molding location is also at the first temperature), resulting in poor fluidity of the injection molding material and inability to fully fill. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 It is a schematic diagram of the assembly of the first mold and the second mold of the present invention; Figure 2 The three-dimensional structure of the first mold and the second mold of the present invention is cut away Figure 1 ; Figure 3 It is a schematic diagram of the partial structure of the first mold and the second mold of the present invention; Figure 4 It is a schematic diagram of assembling the first mold core, the first slider and the impeller rotor of the present invention; Figure 5 The three-dimensional structure of the first mold and the second mold of the present invention is cut away Figure 2 ; Figure 6It is a schematic diagram of the three-dimensional structure of the first mold and the impeller rotor of the present invention; Figure 7 It is a schematic diagram of the three-dimensional structure of the impeller rotor of the present invention; Figure 8 Schematic diagram of the three-dimensional structure of the press tooling of the present invention Fig. 9 It is a three-dimensional structural cross-sectional view of the press tooling of the present invention; Fig.10 This is a schematic product diagram of the part to be injection molded (the impeller rotor semi-finished product after the first injection molding) of the present invention.

[0017] Reference numerals: 11-first mold; 111-first mold frame; 112-first mold core; 113-first slider; 1131-oblique guide column hole; 114-slider core; 12-second mold; 121-oblique guide column; 2-insert; 4-press tooling; 41-base; 42-positioning bracket; 421-bracket body; 422-first groove; 423-second groove; 424-limiting part; 425-narrow neck area; 43-guide column; 44-punch; 6-impeller rotor; 61-annular groove; 62-thin wall; 63-aluminum iron boron magnet. DETAILED DESCRIPTION

[0018] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0019] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0020] The impeller rotor, a component of the brushless electronic water pump, needs to be injected twice during the production process: the first injection molding requires the aluminum iron boron magnet (ring shape) to be embedded in its outer wall to obtain Fig.10 The second injection molding needs to be performed on the basis of the molded part to be molded, and the aluminum iron boron magnet is wrapped to prevent it from rusting and cracking, so as to obtain the following Figure 3 and Figure 7 The impeller rotor is shown.

[0021] PPS (polyphenylene sulfide) injection molding requires the mold temperature to be controlled between 120 and 160 degrees Celsius. In order to maximize the degree of crystallization of the material, obtain a high degree of crystallization and a smooth product surface, and reduce shrinkage after molding, the mold temperature should not be lower than 120 degrees Celsius; during the secondary injection molding of the impeller rotor, the wall thickness (the gap between the outer surface of the aluminum iron boron magnet and the inner wall of the insert) is only 0.5-0.6mm (i.e., thin wall 62), and the injection molding material needs to maintain a high fluidity, so the temperature at the molding point should reach 170-190 degrees Celsius; however, if the injection molding machine heating system is used to keep the mold at such a high temperature, the overall mold frame, guide pins and guide sleeves, and various transmission components will be affected to varying degrees, and the injection molding machine heating system is also difficult to ensure the required temperature at the molding point (thin wall 62), and normal and stable production cannot be achieved.

[0022] In summary, refer to Figures 1 to 10 As shown, an embodiment of the present invention provides an impeller rotor injection molding device for an electronic water pump, including an injection molding machine, a mold, an insert 2, an oven and a press tooling 4.

[0023] The mold is installed on the injection molding machine, and has a first mold 11 and a second mold 12, which are used for injection molding of the molded part; during the injection molding process, the first mold 11 and the second mold 12 are controlled at a first temperature, and the first temperature here is achieved by the temperature control module (i.e., the injection molding machine heating system) in the existing injection molding machine to ensure the fluidity of the plastic particles in the mold flow channel. In some practical applications, the first mold 11 is a movable mold, and the second mold 12 is a fixed mold.

[0024] The insert 2 is detachably arranged on the second mold 12, and after the molds are closed, it cooperates with the first mold 11, the second mold 12, and the part to be injected placed on the first mold 11 to form an injection molding cavity; during the injection molding process, the molding part of the cavity is controlled at a second temperature, so that the injection material (for example, polyphenylene sulfide containing 40% glass fiber) can flow in the cavity with a gap of 0.5-0.6mm (the gap between the outer surface of the aluminum iron boron magnet and the inner wall of the insert), wherein the first temperature is lower than the second temperature (in some practical applications, the first temperature is 120-160 degrees Celsius, and the second temperature is 170-190 degrees Celsius); after injection molding and mold opening, the insert 2 is coaxially coated on the outside of the injection molded impeller rotor 6 and is out of contact with the second mold 12; an oven is arranged next to the injection molding machine for heating the insert 2; a press tooling 4 is arranged next to the injection molding machine for separating the insert 2 from the injection molded impeller rotor 6.

[0025] In actual use, the insert 2 is first placed in an oven for heating, so that the insert 2 reaches the temperature set in the oven (in some practical applications, the set temperature is 190 degrees Celsius) to ensure the temperature of the molding during the injection molding process. At the same time, it is ensured that the first mold 11 and the second mold 12 of the mold are in normal state, and the temperature control module controls the first mold 11 and the second mold 12 to be at the first temperature.

[0026] Then, the heated insert 2 is installed on the second mold 12. The part to be injected is placed on the first mold 11, and is ready for mold closing and injection molding. The first mold 11 and the second mold 12 are closed, and the insert 2 cooperates with the first mold 11, the second mold 12 and the part to be injected placed on the first mold 11 to form a cavity for injection molding. Since the insert 2 has been heated to 190 degrees Celsius in the oven, after the mold closing is completed, the temperature at the molding site can basically reach 180 degrees Celsius (considering the temperature drop caused by heat transfer during the process of taking the insert out of the oven and closing the mold), ensuring that the polyphenylene sulfide containing 40% glass fiber can have good fluidity in the cavity with a gap of 0.5-0.6mm, and the injection molding is completed, so that the impeller rotor has a thin wall 62 of 0.5-0.6mm, which not only meets the assembly requirements of the impeller rotor and the stator core, but also meets the requirements of the impeller rotor to operate stably between minus 40 degrees and 120 degrees.

[0027] After the injection molding is completed, the first mold 11 and the second mold 12 are opened, and the insert 2 is coaxially wrapped around the impeller rotor 6 after injection molding, and is separated from the second mold 12. The insert 2 and the impeller rotor 6 after injection molding are separated by using the press tooling 4 arranged next to the injection molding machine to obtain the final impeller rotor 6 product.

[0028] The insert 2 is heated in an oven and then placed on the second mold 12. The heated insert 2 is used as one of the components forming the injection molding cavity, so that the temperature of the molding location can be controlled at the second temperature. That is, the insert 2, which is separable from the mold, is used as one of the components forming the injection molding cavity and as a core component for controlling the temperature of the molding location. Even if the gap between the outer surface of the aluminum iron boron magnet and the inner wall of the insert 2 is only 0.5-0.6mm, it can ensure that the injection molding material has high fluidity, thereby obtaining a high degree of crystallization and a smooth product surface.

[0029] In addition, the heating system of the injection molding machine controls the overall temperature of the mold at the first temperature, and the temperature of the molding location is controlled by the insert 2 at the second temperature, so as to achieve different temperatures in different parts. This can avoid the problem that the mold as a whole is kept at a high temperature at the second temperature, resulting in the overall mold frame, guide pillars and guide sleeves, and various transmission components being affected to varying degrees. It can also avoid the problem that the mold as a whole is kept at the first temperature (the temperature at the molding location is also at the first temperature), resulting in poor fluidity of the injection molding material and inability to fully fill.

[0030] In some practical applications, there are at least two inserts 2, at least one of which is located in the oven for heating, and at least one is located in the mold for injection molding. After the insert 2 involved in molding is separated from the impeller rotor 6 after injection molding, the insert 2 originally in the oven is taken out and placed on the second mold 12 for the next molding operation. At the same time, the previous insert 2 that participated in molding and was separated from the impeller rotor 6 after injection molding is placed in the oven for heating. Such alternating operations greatly improve production efficiency. In the actual production process, most molds can complete the processing of two products in one injection molding process, so at least four inserts 2 need to be prepared; while two of the inserts 2 are located in the oven for heating, the other two inserts 2 participate in the molding operation.

[0031] In some practical applications, refer to Figures 2 to 7 ,and Fig.10 As shown, since the impeller rotor 6 is a rotating circular part, the neck of the impeller rotor 6 has an annular groove 61, so the first mold 11 is optimized and designed, specifically as follows: the first mold 11 includes a first mold frame 111, a first mold core 112, a first slider 113 and a slider core 114. The first mold core 112 is arranged on the first mold frame 111; the first slider 113 is slidably arranged on the first mold core 112; the slider core 114 is connected or integrally formed on the first slider 113; in the mold closing state, the slider core 114 cooperates with the insert 2, the second mold 12, and the part to be injected placed on the first mold 11 to form an injection molding cavity. In the mold closing state after injection molding, the slider core 114 is embedded in the annular groove 61 of the neck of the impeller rotor 6 after injection molding. Generally speaking, there are two sliders arranged relatively, so there are also two slider cores 114. The two slider cores 114 are stuck in the annular groove 61 in the mold closing state to prevent the injection material from flowing into the annular groove 61.

[0032] Specifically, the design of the first slider 113 and the slider core 114 can refer to the prior art (in many mold designs, the product often has lateral holes, grooves or protrusions and other structures, and lateral parting or core pulling operations need to be performed when the mold is opened in order to smoothly remove the product. The inclined guide rod pushes the slider to open, which enables the slider to move along a specific path, thereby realizing lateral parting or core pulling, separating the product from the lateral part of the mold, and avoiding damage to the product during demolding). Generally speaking, a mold will be provided with at least two sliders; as shown in the figure, the first mold 11 has at least two first sliders 113 arranged opposite to each other, and the first slider 113 is provided with an inclined guide column hole 1131 extending obliquely, and the second mold 12 has a corresponding inclined guide column 121. Through the sliding cooperation between the inclined guide column and the inclined guide column hole, the two first sliders 113 can be driven away from each other when the first mold 11 and the second mold 12 are opened, so as to facilitate the removal of the insert 2 and the impeller rotor 6 after injection molding.

[0033] In some practical applications, because the impeller rotor 6 is a rotating circular part, on the one hand, the length of the thin wall 62 is relatively long (generally up to about 40 mm) and the thickness is relatively thin (about 0.5-0.6 mm), and on the other hand, the slider core 114 is embedded in the annular groove 61 of the neck of the injection-molded impeller rotor 6. After the injection molding is completed, if the mold of the injection-molded impeller rotor 6 is directly separated by the opening action of the first mold 11 and the second mold 12, the molded impeller rotor 6 is easily Therefore, the detachable design of the insert 2 and the second mold 12 (a transition fit is adopted between the insert and the second mold, so that the insert 2 is easy to be placed on the second mold and also easy to be removed from the second mold) can avoid this problem. That is, after the mold is demolded, the insert 2 is still sleeved on the outside of the thin wall 62 of the impeller rotor 6. At this time, the staff can remove the insert 2 and the impeller rotor 6 together, and then use the above-mentioned press tooling 4 to separate the two.

[0034] According to the above problems, the structure of the press tooling 4 is designed: Figures 8 to 9 As shown, the press tooling 4 includes a base 41 , a positioning bracket 42 , a guide column 43 and a punch 44 .

[0035] The positioning bracket 42 is arranged on the base 41, and is used to place the insert 2 to be separated and the impeller rotor 6 after injection molding; the guide column 43 is arranged on the base 41; the punch 44 is slidably arranged on the guide column 43, and can move relative to the positioning bracket 42 so as to separate the insert 2 and the impeller rotor 6 after injection molding.

[0036] Specifically, the positioning bracket 42 includes a bracket body 421 and two slots (respectively a first slot 422 and a second slot 423 ). The bracket body 421 is arranged on the base 41; the first groove 422 is located at the upper part of the bracket body 421; the second groove 423 is located at the lower part of the bracket body 421; the limiting portion 424 is located between the first groove 422 and the second groove 423, so that a U-shaped narrow neck area 425 is formed at the junction of the first groove 422 and the second groove 423, and the width of the narrow neck area 425 is greater than the inner diameter of the insert 2 and smaller than the outer diameter of the insert 2; when the insert 2 to be separated and the impeller rotor 6 after injection molding are placed on the positioning bracket 42, the insert 2 is coaxial with the punch 44, the impeller part of the impeller rotor 6 is located in the second groove 423, the upper end surface of the limiting portion 424 is against the lower end surface of the insert 2, and a gap is left between the end of the limiting portion 424 and the bottom wall of the annular groove 61 of the neck of the impeller rotor 6 (the setting of the gap facilitates the impeller rotor 6 to be inserted or slide into the limiting portion 424).

[0037] The size of the punch 44 is generally slightly smaller than the inner diameter of the insert 2, and is adapted to the size of the end of the impeller rotor 6. By controlling the downward movement of the punch 44, the end of the impeller rotor can be acted on. Since the insert 2 is limited on the limit portion 424, the impeller rotor will fall off from the insert 2 under the action of the punch 44, thereby achieving separation of the two. In this process, since the impeller rotor is not constrained or limited by the first die 11 and the second die 12, it will not be pulled apart.

[0038] A method for injection molding an impeller rotor of an electronic water pump, using the above-mentioned injection molding device for injection molding, comprises the following steps: S1: Start the injection molding machine, control the temperature of the first mold 11 and the second mold 12 to a first temperature, and place the molded part in the first mold 11 of the mold; S2: Turn on the oven, place the insert 2 in the oven for heating, and place the heated insert 2 in the second mold 12 of the mold, so that the cavity molding part is controlled at the second temperature; S3: Clamp the first mold 11 and the second mold 12 so that the insert 2 cooperates with the first mold 11, the second mold 12, and the part to be injected placed on the first mold 11 to form an injection molding cavity; inject into the cavity so that the injection molding material can flow in the cavity with a gap of 0.5-0.6 mm; S4: opening the mold after injection molding, so that the insert 2 is coaxially wrapped around the impeller rotor 6 after injection molding and is out of contact with the second mold 12; S6: Remove the insert 2 and the injection-molded impeller rotor 6 from the first mold 11, place them on the press tooling 4, separate the insert 2 and the injection-molded impeller rotor 6, and the obtained impeller rotor 6 has a thin wall 62 of 0.5-0.6 mm.

[0039] In addition, it should be noted that there are at least two inserts 2, at least one of which is located in an oven for heating, and at least one is used for injection molding.

[0040] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An impeller rotor injection molding device for an electronic water pump, characterized in that: It comprises an injection molding machine, a mold, an insert (2), an oven and a press tooling (4), wherein: A mold, mounted on an injection molding machine, comprising a first mold (11) and a second mold (12), for injection molding a part to be molded; during the injection molding process, the first mold (11) and the second mold (12) are controlled at a first temperature; The insert (2) is detachably arranged on the second mold (12), and cooperates with the first mold (11), the second mold (12), and the part to be injected placed on the first mold (11) to form an injection molding cavity after the molds are closed; during the injection molding process, the molding part of the cavity is controlled at a second temperature so that the injection molding material can flow in the cavity with a gap of 0.5-0.6 mm; after the injection molding and the mold opening, the insert (2) coaxially covers the outside of the injection molded impeller rotor (6) and is separated from the contact with the second mold (12); An oven, arranged beside the injection molding machine, for heating the insert (2); A press tool (4) is arranged beside the injection molding machine and is used to separate the insert (2) from the impeller rotor (6) after injection molding; The first temperature is lower than the second temperature.

2. The impeller rotor injection molding device of the electronic water pump according to claim 1, characterized in that: The first temperature is 120-160 degrees Celsius, and the second temperature is 170-190 degrees Celsius.

3. The impeller rotor injection molding device of the electronic water pump according to claim 1, characterized in that: There are at least two inserts (2), at least one of which is located in an oven for heating, and at least one is located in the mold for injection molding.

4. The impeller rotor injection molding device for an electronic water pump according to claim 1, characterized in that: The injection molding material is polyphenylene sulfide containing 40% glass fiber.

5. The impeller rotor injection molding device for an electronic water pump according to claim 1, characterized in that: The first mold (11) comprises: A first mold frame (111); A first mold core (112) is disposed on the first mold frame (111); A first sliding block (113) is slidably disposed on the first mold core (112); The slider core (114) is connected to or integrally formed on the first slider (113); in a mold-closing state, the slider core (114) cooperates with the insert (2), the second mold (12), and the part to be molded placed on the first mold (11) to form a mold cavity for injection molding.

6. The impeller rotor injection molding device for an electronic water pump according to claim 5, characterized in that: In a mold-closing state after injection molding, the slider core (114) is embedded in the annular groove (61) of the neck of the injection-molded impeller rotor (6).

7. The impeller rotor injection molding device for an electronic water pump according to claim 1, characterized in that: The press tooling (4) comprises: Base (41); A positioning bracket (42) is arranged on the base (41) and is used to place the insert (2) to be separated and the impeller rotor (6) after injection molding; A guide column (43) is disposed on the base (41); The punch (44) is slidably disposed on the guide column (43) and is capable of moving relative to the positioning bracket (42) so as to separate the insert (2) and the impeller rotor (6) after injection molding.

8. The impeller rotor injection molding device for an electronic water pump according to claim 7, characterized in that: The positioning bracket (42) comprises: A support body (421) is disposed on the base (41); A first groove (422) is located on the upper portion of the bracket body (421); A second groove (423) is located at the lower part of the bracket body (421); The limiting portion (424) is located between the first groove (422) and the second groove (423), so that a U-shaped narrow neck region (425) is formed at the junction of the first groove (422) and the second groove (423), and the width of the narrow neck region (425) is greater than the inner diameter of the insert (2) and smaller than the outer diameter of the insert (2); When the insert (2) to be separated and the impeller rotor (6) after injection molding are placed on the positioning bracket (42), the insert (2) and the punch (44) are coaxial, the impeller portion of the impeller rotor (6) is located in the second groove (423), the upper end surface of the limiting portion (424) abuts against the lower end surface of the insert (2), and a gap is left between the end of the limiting portion (424) and the bottom wall of the annular groove (61) of the neck of the impeller rotor (6).

9. A method for injection molding an impeller rotor of an electronic water pump, characterized in that: The injection molding device according to any one of claims 1 to 8 is used for injection molding, comprising: Starting the injection molding machine, controlling the temperature of the first mold (11) and the second mold (12) to a first temperature, and placing the part to be injection molded in the first mold (11) of the mold; Turning on the oven, placing the insert (2) in the oven for heating, and placing the heated insert (2) in the second mold (12) of the mold, so that the cavity molding portion is controlled at the second temperature; The first mold (11) and the second mold (12) are combined so that the insert (2) cooperates with the first mold (11), the second mold (12), and the part to be molded placed on the first mold (11) to form a mold cavity for injection molding; and injection molding is performed into the mold cavity so that the injection molding material can flow in the mold cavity with a gap of 0.5-0.6 mm; After the injection molding, the mold is opened so that the insert (2) coaxially covers the outside of the injection molded impeller rotor (6) and is separated from the contact with the second mold (12); The insert (2) and the injection-molded impeller rotor (6) are removed from the first mold (11), placed on a press tooling (4), and the insert (2) and the injection-molded impeller rotor (6) are separated.

10. The method for injection molding an impeller rotor of an electronic water pump according to claim 9, characterized in that: There are at least two inserts (2), at least one of which is located in an oven for heating, and at least one is used for injection molding.

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