Electric fuel pump impeller with self-rotating demoulding structure

Abstract

An electric fuel pump impeller with a self-rotating demoulding structure, by setting the positive blades and negative blades on the impeller body into a symmetrical structure. The symmetrical positive and negative blades can, during the demoulding process of the impeller, enable the impeller body to receive the force of mold opening. The force acts on the positive and negative blades, thereby driving the impeller body to rotate self, thus realizing the function of self-rotating demoulding. No additional demoulding mechanism is required, simplifying the demoulding process, reducing the demoulding difficulty, and improving the production efficiency. At the same time, by setting structures such as a flow guiding surface, a wedge-shaped groove, and an arc-shaped flow guiding surface, the flow path of the oil fluid is optimized, the resistance of the oil fluid in the impeller is reduced, and the oil pumping efficiency and performance of the electric fuel pump are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel pumps, and particularly to an electric fuel pump impeller with a self-rotating demolding structure. Background Art

[0002] In the prior art, a spiral demolding mechanism is usually required for impeller demolding. This demolding method not only has a complex structure but also low demolding efficiency. During the demolding process, the spiral demolding mechanism is likely to scratch the surface of the impeller, affecting the appearance quality and service performance of the impeller. In addition, the spiral demolding mechanism also requires a large amount of space. Moreover, the blade structure of the traditional fuel pump impeller is a curved surface structure. When using the mold spiral demolding mechanism for demolding, the mold can only produce a one-cavity or two-cavity structure. At the same time, the service life of the spiral demolding mechanism is often only 100,000 molds. The reason is that the spiral mechanism of the mold is worn, resulting in a large misalignment between the front and back blades of the impeller and large flash and burrs on the impeller, making it impossible to continue using. Summary of the Invention

[0003] In view of this, the present invention provides an electric fuel pump impeller with a self-rotating demolding structure.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] An electric fuel pump impeller with a self-rotating demolding structure includes an impeller body formed on an impeller mold. A blade ring groove is provided on the impeller body. Impeller blades are arranged in the blade ring groove. The impeller blades have positive blades and negative blades symmetrically arranged based on the center line on the circumferential surface where the blade ring groove is located. The impeller blades are respectively inclined from both side notches of the blade ring groove towards the center line on the circumferential surface where the blade ring groove is located. The impeller mold enters the blade ring groove from the directions of the positive blades and negative blades respectively. During the demolding process of the impeller body, self-rotating demolding is performed on the mold.

[0006] Preferably, the impeller mold includes a moving mold and a stationary mold. Moving mold connection structures and stationary mold connection structures corresponding to the internal shape of the blade ring groove are provided on both the moving mold and the stationary mold. The impeller body is placed between the moving mold and the stationary mold. In the open state of the moving mold, the impeller body rotates towards the moving mold along the axial direction of the stationary mold on the stationary mold.

[0007] Preferably, an included angle α is formed between the positive blade and the negative blade. The positive blade and the negative blade both have corresponding self-locking angles θ. The included angle α between the positive blade and the negative blade is greater than the self-locking angle θ corresponding to the positive blade or the negative blade.

[0008] Preferably, the impeller body has two guiding surfaces, and a plurality of wedge-shaped grooves are formed on each guiding surface and are arranged in an annular array with the axial center line of the impeller body as the reference. Each wedge-shaped groove has two inclined transition groove walls.

[0009] Preferably, the inclination angle of the transition groove wall is 10°-30°.

[0010] Preferably, an interference contact end protrudes from the outer ring of the impeller body, and the outer diameter of the interference contact end exceeds the parts of the outer ring of the impeller body on both sides of the interference contact end by 0.02-0.06 mm.

[0011] Preferably, the two guiding surfaces include a first guiding surface and a second guiding surface. An impeller rubber port is concavely formed on the first guiding surface, and the inner wall of the impeller rubber port is arranged in an inclined structure. The inclination angle of the inner wall of the impeller rubber port is 5°.

[0012] Preferably, arc-shaped guiding surfaces protrude from the opposite groove walls on both sides of the blade ring groove of the impeller body toward the center line on the circumferential surface where the blade ring groove is located.

[0013] Preferably, the impeller blade has an oil inlet surface and an oil outlet surface, and a guiding plane is arranged on the oil outlet surface.

[0014] The beneficial effects of the present invention are as follows: By setting the positive blades and negative blades on the impeller body into a symmetrical structure, during the demolding process of the impeller, the impeller body is subjected to the demolding force of the mold. The force acts on the positive and negative blades, thereby driving the impeller body to rotate self - rotatably, thus realizing the function of self - rotating demolding. No additional demolding mechanism is required, the demolding process is simplified, the demolding difficulty is reduced, and the production efficiency is improved. At the same time, by setting structures such as guiding surfaces, wedge - shaped grooves, and arc - shaped guiding surfaces, the flow path of the oil fluid is optimized, the resistance of the oil fluid in the impeller is reduced, and the oil pumping efficiency and performance of the electric fuel pump are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Attached Figure 1 is a schematic diagram of the impeller body;

[0017] Attached Figure 2 is a schematic diagram of the impeller body from another angle;

[0018] AttachedFigure 3 is an attached Figure 2 sectional view at A-A in the figure;

[0019] attached Figure 4 is a schematic diagram of the force analysis of the positive and negative blades;

[0020] attached Figure 5 is a sectional view of a single blade groove;

[0021] attached Figure 6 is a sectional view of a single blade groove from another angle;

[0022] attached Figure 7 is a schematic diagram of a wedge-shaped groove;

[0023] attached Figure 8 is a schematic diagram of the impeller rubber joint;

[0024] attached Figure 9 is an attached Figure 3 schematic diagram from another angle;

[0025] attached Figure 10 is an attached Figure 3 schematic diagram from another angle. Specific implementation manners

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] Next, the present invention will be further described in conjunction with the accompanying drawings of the specification.

[0028] The present invention provides the following technical solutions:

[0029] As shown in the attached Figures 1-10As shown in the figure, the present invention discloses an electric fuel pump impeller with a self-rotating demolding structure, which includes an impeller body 1 formed on an impeller mold. A blade ring groove 2 is formed on the impeller body 1, and impeller blades 3 are arranged in the blade ring groove 2. The impeller blades 3 have positive blades 4 and negative blades 5 that are symmetrically arranged based on the center line on the circumferential surface where the blade ring groove 2 is located. The positive blades 4 and negative blades 5 are arranged in a "V" structure. The two side edges of the positive blades 4 and negative blades 5 are respectively in contact with the inner wall of the blade ring groove 2, so that the impeller blades 3 are stably installed in the blade ring groove 2. The impeller blades 3 respectively enter the blade ring groove 2 from the two side notches of the blade ring groove 2 towards the center line on the circumferential surface where the blade ring groove 2 is located, and the impeller mold enters the blade ring groove 2 to be connected with the impeller body 1 from the directions of the positive blades 4 and negative blades 5 respectively. During the demolding process of the impeller body 1, self-rotating demolding is carried out on the mold. Specifically, in this design, the impeller body 1 is arranged on the mold. When the mold is opened, due to the symmetrically arranged positive blades 4 and negative blades 5 on the impeller body 1, and there is an included angle α between the positive blades 4 and negative blades 5; after the impeller is injection-molded, the mold core and the impeller cannot be directly demolded. When the mold core is opened, the mold core generates a force F on the V-shaped teeth of the impeller. F is as shown in Figure 2As shown in the figure, force F can be decomposed into two forces F1 and F2. It can be seen that the directions of F1 and F2 are the same, and these two forces will cause the impeller to rotate; the magnitudes of F2 and F2' are equal and the directions are opposite, and these forces cancel each other out; the material of the impeller body is PPS-GF65 (glass fiber reinforced polyphenylene sulfide material), and the friction coefficient between it and the steel mold is: μ is about 0.9 (the factors of high temperature and high pressure need to be considered); the self-locking angle θ for the impeller and the mold core not to be demolded is θ = tan(μ / 2) = 48.5°; when the V-shaped angle is α = θ°, at the moment of opening the mold, the impeller cannot rotate by itself, the impeller cannot be demolded, and the demolding action is forcibly interrupted; while when the angle is α > θ°, at the moment of opening the mold, the impeller can rotate by itself and the impeller can be screwed out from the mold core; considering factors such as the machining error of the tooth shape position of the mold core impeller and the increased pressure after material injection, α can be set above 90°. In this design, the through-hole core on the impeller is pulled out in advance, and at this time the impeller has the ability to rotate by itself. At this time, the spiral mechanism of the mold can be cancelled, the structure and size of the impeller mold are greatly simplified, and the impeller mold can achieve the ability of more than one out of two. The positive and negative blades 5 in the impeller blade 3 are axially symmetric structures. The existing blades are formed by a spiral scan of a forming line along a spiral line with the center line of the impeller cylinder as the axis into a curved surface. The oil inlet surface 13 and the oil outlet surface 14 of the blade are both formed in this way. The difference is that the spiral angles differ by 1.5° to 3°, and the purpose is to facilitate demolding; thus, it can be seen that the mold needs to process the blade mold core by a rotational pulse processing method, resulting in a relatively high mold cost; the present invention innovatively designs the forming surface of the impeller blade 3, and uses a flat oil inlet surface and an oil outlet surface to replace the curved surface oil inlet surface and oil outlet surface. That is, the forming line is a straight line, and a flat surface is formed by means of linear stretching. Although there is a slight interference between the blade and the mold core when the flat blade is demolded, the interference amount is less than 0.01 mm³, which is within the elastic deformation range of the material and can be ignored; at this time, the blade mold core in the impeller mold no longer needs precision spiral electric pulse processing, and the mold processing cost will be greatly reduced; at the same time, combined with the above analysis, the designed impeller mold can cancel the spiral demolding mechanism, and the processing cost is reduced by 50% compared with the original one.

[0030] Furthermore, the impeller mold includes a movable mold (not shown in the figure) and a stationary mold (not shown in the figure). Both the movable mold and the stationary mold are provided with a movable mold connection structure and a stationary mold connection structure corresponding to the internal shape of the blade ring groove 2. The impeller body 1 is placed between the movable mold and the stationary mold. In the open state of the movable mold, the impeller body 1 rotates along the axial direction of the stationary mold towards the movable mold. Specifically, in this embodiment, the movable mold connection structure and the stationary mold connection structure are respectively designed as concave-convex structures matching the internal shape of the blade ring groove to ensure that the movable mold and the stationary mold can tightly clamp the impeller body in the closed state, avoiding resin leakage during the injection molding process. At the same time, this design also enables the movable mold and the stationary mold to be smoothly separated during the demolding process without damaging the impeller body 1. In the open state, the impeller body 1 can rotate along the axial direction of the stationary mold towards the movable mold. During the mold opening process, the movable mold moves away from the stationary mold. At the same time, the stationary mold remains relatively fixed, so that the impeller body between the movable mold and the stationary mold can gradually break free from the restraint of the stationary mold as the movable mold moves, thereby realizing the automatic rotary demolding of the impeller. This design is the key to realizing self-rotary demolding. By rotating the impeller body, the impeller blades that were originally tightly combined with the mold can be gradually separated from the mold, thus realizing demolding. During this process, since the impeller body rotates on the stationary mold, no additional demolding mechanism is required, which simplifies the mold structure and reduces the processing cost.

[0031] Furthermore, an included angle α is formed between the positive blades 4 and the negative blades 5. Both the positive blades 4 and the negative blades 5 have corresponding self-locking angles θ, and the included angle α between the positive blades 4 and the negative blades 5 is greater than the self-locking angle θ corresponding to the positive blades 4 or the negative blades 5. Specifically, in this embodiment, since the included angle α between the positive blades 4 and the negative blades 5 is greater than the self-locking angle θ corresponding to the positive blades 4 or the negative blades 5, the positive blades and the negative blades can better maintain their shapes and positions during the injection molding process and are not easily deformed or displaced. At the same time, since the included angle α is greater than the self-locking angle θ, the positive blades and the negative blades can be more smoothly separated from the mold during the demolding process, avoiding problems such as blade damage or mold damage caused by mold clamping. This design not only improves the production efficiency of the impeller but also reduces the production cost, providing strong support for the performance improvement of the electric fuel pump.

[0032] Furthermore, the impeller body 1 has two guiding surfaces, and a number of wedge-shaped grooves 6 arranged in an annular array with the axial center line of the impeller body 1 as the reference are provided on each of the guiding surfaces. Each of the wedge-shaped grooves 6 has two inclined transition groove walls 7. Specifically, in this embodiment, the arrangement of the wedge-shaped grooves 6 can utilize the principle of hydrodynamic thrust bearings during the operation of the impeller. When the impeller rotates, an oil film is formed on the upper and lower surfaces of the impeller by the wedge-shaped grooves 6, reducing the wear between the impeller and the pump body and pump cover, improving the service life of the electric fuel pump, and also reducing the problem of high noise caused by direct friction between the impeller and the pump body and pump cover. In order to achieve self-rotating demolding of the impeller, a spiral transition structure needs to be added to the wedge-shaped grooves 6 in the impeller demolding rotation direction to avoid interference between the impeller and the mold. Moreover, the arrangement of the wedge-shaped grooves 6 can optimize the fluid flow path, reduce the resistance and eddy current of the fluid on the impeller body 1, and improve the efficiency and performance of the fuel pump. The inclined design of the transition groove walls 7 enables the fluid to flow more smoothly when passing through the wedge-shaped grooves 6, avoiding the retention and scouring of the fluid at the groove walls, thereby extending the service life of the impeller body 1. In addition, the wedge-shaped grooves 6 and the transition groove walls 7 on the two guiding surfaces cooperate with each other to form a more complex fluid channel, enhancing the hydrodynamic characteristics of the impeller body 1 and enabling the fuel pump to better adapt to different working conditions.

[0033] Furthermore, the inclination angle of the transition groove wall 7 is 10° - 30°. Specifically, by providing the transition groove wall 7, the fluid can flow more smoothly along the transition groove wall 7 during the self-rotating demolding process of the impeller body 1, reducing the resistance of the fluid during the demolding process and further improving the demolding efficiency. In addition, when the inclination angle of the transition groove wall 7 is within the range of 10° - 30°, a stable oil film can be ensured when the fluid flows through the wedge-shaped grooves 6 and the transition groove walls 7, reducing the scouring of the fluid on the impeller body 1 and the mold, thereby extending the overall service life. Moreover, the fluid can flow more smoothly when passing through the wedge-shaped grooves 6, further reducing the retention and scouring of the fluid at the groove walls. The selection of the inclination angle is carefully calculated. The range of 10° - 30° can not only ensure the smooth flow of the fluid but also avoid the fluid pressure loss caused by excessive inclination.

[0034] Furthermore, an interference contact end 8 protrudes from the outer ring of the impeller body 1, and the outer diameter of the interference contact end 8 exceeds the parts of the outer ring of the impeller body 1 on both sides of the interference contact end 8 by 0.02 - 0.06 mm. Specifically, in this embodiment, the protrusion of the interference contact end 8 on the outer ring of the impeller body 1 can avoid the risk of the impeller hanging on the stationary mold during self-rotating demolding, realizing the full-automatic production of the impeller.

[0035] Furthermore, the two guiding surfaces include a first guiding surface 9 and a second guiding surface 10, the first guiding surface 9 and the second guiding surface 10 are respectively formed on two opposite end faces of the impeller body 1, an impeller rubber port 11 is concavely formed on the first guiding surface 9, the inner wall of the impeller rubber port 11 is arranged in an inclined structure, and the inclination angle of the inner wall of the impeller rubber port 11 is 5°. Specifically, in this embodiment, the depth of the impeller rubber port 11 needs to be controlled, and the inner wall of the impeller rubber port 11 has a draft angle of 5°, reducing the interference amount with the mold core when the impeller spins out of the mold.

[0036] Furthermore, on the opposite groove walls on both sides of the blade ring groove 2 of the impeller body 1, arc-shaped guiding surfaces 12 protrude towards the center line on the circumferential surface where the blade ring groove 2 is located. Specifically, in this embodiment, by arranging the arc-shaped guiding surfaces 12 on the opposite groove walls on both sides of the blade ring groove 2, the flow path of the fluid can be further optimized, reducing the eddy current and resistance of the fluid in the blade ring groove 2, thereby improving the working efficiency of the impeller. This design can not only improve the fluidity of the fluid but also effectively reduce the energy loss of the fluid, making the entire impeller more efficient and stable during operation. In addition, the setting of the arc-shaped guiding surfaces 12 also enhances the durability of the impeller, reduces the wear caused by fluid erosion, and extends the service life of the impeller.

[0037] Furthermore, the impeller blade 3 has an oil inlet surface 13 and an oil outlet surface 14, and a guiding plane 15 is arranged on the oil outlet surface 14. Specifically, in this embodiment, both the positive blade 4 and the negative blade 5 have corresponding oil inlet surfaces 13 and oil outlet surfaces 14, and the oil inlet surface 13 and the oil outlet surface 14 are respectively formed on two opposite end faces of the positive blade 4 and the negative blade 5. The design of the guiding plane 15 on the oil outlet surface 14 aims to guide the flow direction of the fluid when it leaves the blade, ensuring that the fluid can flow out smoothly from the oil outlet surface 14, further reducing the eddy current and resistance.

[0038] And the guiding plane 15 is arranged on all the oil outlet surfaces 14, and this guiding plane 15 can effectively guide the flow of the oil on the impeller blade 3, improving the smoothness and efficiency of the oil flow. At the same time, the setting of this guiding plane 15 can also reduce the residence time of the oil on the oil outlet surface 14 of the blade, reduce the heat and wear generated by the long-term residence of the oil, thereby extending the service life of the impeller.

[0039] The oil outlet surfaces 14 of the positive blade 4 and the negative blade 5 are both composed of a straight surface (i.e., the flow guiding plane 15) and an arc surface 16. The length of the straight surface is greater than that of the arc surface 16. Such a design aims to optimize the flow characteristics of the oil. The fact that the length of the straight surface is greater than that of the arc surface ensures that the oil can maintain a relatively stable flow rate and pressure distribution when flowing through the oil outlet surface. The longer straight surface helps to reduce the formation of turbulence and eddy currents, making the oil flow more smoothly and reducing energy loss. At the same time, the existence of the arc surface 16 guides the oil to make a smooth transition to a certain extent, further enhancing the stability of the flow. In summary, the design of the oil outlet surfaces 14 of the positive blade 4 and the negative blade 5 effectively improves the stability of the oil flow through the reasonable combination of the straight surface and the arc surface.

[0040] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electric fuel pump impeller with a self-rotating demolding structure, comprising an impeller body formed on an impeller mold, a blade ring groove is formed on the impeller body, and impeller blades are arranged in the blade ring groove, and the characteristics are as follows: The impeller blades have positive blades and reverse blades symmetrically arranged with respect to the center line on the circumferential surface where the blade ring groove is located. The impeller blades are respectively inclined from the two side notches of the blade ring groove towards the center line on the circumferential surface where the blade ring groove is located. The impeller mold enters the blade ring groove from the directions of the positive blade and the reverse blade respectively. During the demolding process of the impeller body, it rotates and demolds on the mold. An included angle α is formed between the positive blade and the reverse blade. Both the positive blade and the reverse blade have corresponding self-locking angles θ. The included angle α between the positive blade and the reverse blade is greater than the self-locking angle θ corresponding to the positive blade or the reverse blade.

2. The electric fuel pump impeller with a self-rotating demolding structure according to claim 1, characterized in that: The impeller mold includes a moving mold and a stationary mold. Both the moving mold and the stationary mold are provided with a moving mold connection structure and a stationary mold connection structure corresponding to the internal shape of the blade ring groove. The impeller body is placed between the moving mold and the stationary mold. In the state where the moving mold is opened, the impeller body rotates towards the moving mold along the axial direction of the stationary mold on the stationary mold.

3. The electric fuel pump impeller with a self-rotating demolding structure according to claim 1, wherein: The impeller body has two flow guiding surfaces. A number of wedge-shaped grooves are formed on each of the flow guiding surfaces, which are arranged in an annular array with respect to the axial center line of the impeller body as a reference. Each of the wedge-shaped grooves has two inclined transition groove walls.

4. The electric fuel pump impeller with a self-rotating demoulding structure according to claim 3, characterized in that: The inclination angle of the transition groove wall is 10° - 30°.

5. The electric fuel pump impeller with a self-rotating demolding structure according to claim 1, characterized in that: An interference contact end protrudes from the outer ring of the impeller body. The outer diameter of the interference contact end exceeds the parts of the outer ring of the impeller body on both sides of the interference contact end by 0.02 - 0.06 mm.

6. The electric fuel pump impeller with a self-rotating demolding structure according to claim 3, wherein: The two flow guiding surfaces include a first flow guiding surface and a second flow guiding surface. An impeller rubber port is recessed on the first flow guiding surface. The inner wall of the impeller rubber port is arranged in an inclined structure, and the inclination angle of the inner wall of the impeller rubber port is 5°.

7. The electric fuel pump impeller with a self-rotating demolding structure according to claim 1, characterized in that: Arc-shaped flow guiding surfaces protrude from the opposite groove walls on both sides of the blade ring groove of the impeller body towards the center line on the circumferential surface where the blade ring groove is located.

8. The electric fuel pump impeller with a self-rotating demolding structure according to claim 1, characterized in that: The impeller blades have an oil inlet surface and an oil outlet surface. A flow guiding plane is arranged on the oil outlet surface.

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