Electric fuel pump impeller with self-rotating demolding structure

Abstract

According to the electric fuel pump impeller with the self-rotating demolding structure, the positive blades and the negative blades on the impeller body are arranged to be of a symmetrical structure, the symmetrical positive and negative blades can bear the acting force of mold opening in the impeller demolding process, and the acting force acts on the positive and negative blades; therefore, the self-rotating demolding function is achieved, an additional demolding mechanism is not needed, the demolding process is simplified, the demolding difficulty is reduced, and the production efficiency is improved. Meanwhile, by arranging the flow guide faces, the wedge-shaped grooves, the arc flow guide faces and other structures, the flowing path of the oil liquid is optimized, the resistance of the oil liquid in the impeller is reduced, and the oil pumping efficiency and performance of the electric fuel pump are improved.

Description

Technical Field

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

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

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

[0004] To achieve the above object, the present invention provides the following technical solutions: An electric fuel pump impeller with a self-rotating demoulding structure comprises 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 with the center line of the circumferential surface where the blade ring groove is located as a reference, the impeller blades are respectively arranged from the notches on both sides of the blade ring groove to the center line of the circumferential surface where the blade ring groove is located, the impeller mold enters the blade ring groove from the direction of the positive blade and the negative blade respectively, and the impeller body is demoulded by self-rotation on the mold during demoulding.

[0005] Preferably, the impeller mold includes a movable mold and a static mold, and the movable mold and the static mold are both provided with a movable mold connecting structure and a static mold connecting structure corresponding to the internal shape of the blade ring groove. The impeller body is placed between the movable mold and the static mold. When the movable mold is in an open state, the impeller body rotates on the static mold along the axial direction of the static mold toward the movable mold.

[0006] Preferably, the positive blade and the negative blade form an included angle α, and the positive blade and the negative blade both have corresponding self-locking angles θ, and the included angle α between the positive blade and the negative blade is greater than the corresponding self-locking angle θ of the positive blade or the negative blade.

[0007] Preferably, the impeller body has two guide surfaces, each of which is provided with a plurality of wedge-shaped grooves arranged in a circular array based on the axial center line of the impeller body, and each of the wedge-shaped grooves has two inclined transition groove walls.

[0008] Preferably, the inclination angle of the transition groove wall is 10° to 30°.

[0009] Preferably, an interference contact end is protruded on the outer ring of the impeller body, and the outer diameter of the interference contact end exceeds the outer ring of the impeller body and is located on both sides of the interference contact end by 0.02 to 0.06 mm.

[0010] Preferably, the two guide surfaces include a first guide surface and a second guide surface, the first guide surface is concave to form an impeller rubber mouth, the inner wall of the impeller rubber mouth is arranged in an inclined structure, and the inclination angle of the inner wall of the impeller rubber mouth is 5°.

[0011] Preferably, the groove walls on opposite sides of the blade ring groove of the impeller body protrude toward the center line of the circumferential surface where the blade ring groove is located to form an arc guide surface.

[0012] Preferably, the impeller blade has an oil inlet surface and an oil outlet surface, and a guide plane is arranged on the oil outlet surface.

[0013] The beneficial effect of the present invention is that by setting the positive blades and the negative blades on the impeller body into a symmetrical structure, the symmetrical positive and negative blades can, during the process of demoulding the impeller, the impeller body is subjected to the force of mold opening, and the force acts on the positive and negative blades, thereby driving the impeller body to rotate, thereby realizing the function of self-rotation demoulding, without the need for an additional demoulding mechanism, simplifying the demoulding process, reducing the demoulding difficulty, and improving production efficiency. At the same time, by setting structures such as guide surfaces, wedge grooves, and arc guide surfaces, the flow path of the oil is optimized, the resistance of the oil in the impeller is reduced, and the pumping efficiency and performance of the electric fuel pump are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Attached Figure 1 is a schematic diagram of the impeller body; Attached Figure 2 It is a schematic diagram of the impeller body from another angle; Attached Figure 3 For attachment Figure 2 Sectional view at AA; Attached Figure 4 It is a schematic diagram of the force analysis of the positive blade and the reverse blade; Attached Figure 5 It is a cross-sectional view of a single blade slot; Attached Figure 6 It is a cross-sectional view of a single blade slot from another angle; Attached Figure 7 is a schematic diagram of a wedge-shaped slot; Attached Figure 8 This is a schematic diagram of the impeller rubber port; Attached Fig. 9 For attachment Figure 3 Schematic diagram from another angle; Attached Fig.10 For attachment Figure 3 Schematic diagram from another angle. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] The present invention will be further described below in conjunction with the accompanying drawings.

[0018] The present invention provides the following technical solutions: As attached Figure 1-10 As shown, the present invention discloses an electric fuel pump impeller with a self-rotating demoulding structure, comprising an impeller body 1 formed on an impeller mold, a blade ring groove 2 is provided on the impeller body 1, an impeller blade 3 is arranged in the blade ring groove 2, the impeller blade 3 has a positive blade 4 and a negative blade 5 symmetrically arranged with the center line on the circumferential surface where the blade ring groove 2 is located as a reference, and the positive blade 4 and the negative blade 5 are arranged in a "human" structure, and the two side edges of the positive blade 4 and the negative blade 5 are respectively fitted with the inner wall of the blade ring groove 2, so that the impeller blade 3 is stably installed in the blade ring groove 2. The impeller blade 3 is respectively directed from the notches on both sides of the blade ring groove 2 to 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 from the direction of the positive blade 4 and the negative blade 5 to connect with the impeller body 1, and the impeller body 1 is demoulded by self-rotation on the mold during the demoulding process. Specifically, in this design, the impeller body 1 is arranged on the mold. When the mold is opened, due to the symmetrical arrangement of the positive blades 4 and the reverse blades 5 on the impeller body 1, and the angle α between the positive blades 4 and the reverse 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 exerts a force F on the V-shaped teeth of the impeller. F is as follows: Figure 2As shown, F can be decomposed into two forces F1 and F2. It can be seen that the directions of the two forces F1 and F2 are the same. These two forces will cause the impeller to rotate; the two forces F2 and F2' are equal in magnitude and opposite in direction, and the 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 (high temperature and high pressure factors need to be considered); the self-locking angle θ=tan(μ / 2)=48.5° at which the impeller and the mold core cannot be demolded; when the V-shaped angle is α=θ°, the impeller cannot spin at the moment of opening the mold, the impeller will not be able to demold, and the demolding action is forcibly interrupted; and when the angle is α>θ°, the impeller can spin at the moment of opening the mold, and the impeller can be rotated out of the mold core; the processing error of the impeller tooth position in the mold core, the increased pressure after the material is injected, and other factors need to be considered, and α can be set to above 90°. This design pulls out the through-hole core on the impeller in advance, and the impeller has the ability to self-rotate. At this time, the mold can cancel the spiral mechanism, the structure and size of the impeller mold are greatly simplified, and the impeller mold can achieve the ability of one out of two or more. The positive and negative blades 5 in the impeller blade 3 are axially symmetrical structures. The existing blades are formed into a curved surface by spiral scanning of the molding line through a spiral line with the center line of the impeller cylinder as the axis. The blade oil inlet surface 13 and the oil outlet surface 14 are both formed in this way. The difference is that the spiral angle differs by 1.5° to 3°, the purpose is to facilitate demolding; it can be seen that the mold needs to be processed by a rotating pulse for the blade core, resulting in a high mold cost; the present invention has an innovative design for the impeller blade 3 molding surface, using a flat oil inlet surface and an oil outlet surface instead of the oil inlet surface and the oil outlet surface of the curved surface structure. That is, the molding line is a straight line, and the plane is formed by linear stretching. Although there is a slight interference between the blade and the mold core when the flat blade is demoulded, the interference is less than 0.01mm³, which is negligible within the elastic deformation range of the material; at this time, the blade mold core in the impeller mold no longer requires precise 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 demoulding mechanism, reducing the original processing cost by 50%.

[0019] Furthermore, the impeller mold includes a movable mold (not shown) and a static mold (not shown), and the movable mold and the static mold are both provided with a movable mold connection structure and a static mold connection structure corresponding to the internal shape of the blade ring groove 2, and the impeller body 1 is placed between the movable mold and the static mold. When the movable mold is in an open mold state, the impeller body 1 rotates on the static mold along the axial direction of the static mold toward the movable mold. Specifically, in this embodiment, the movable mold connection structure and the static mold connection structure are respectively designed as concave-convex structures matching the internal shape of the blade ring groove, so as to ensure that in the closed mold state, the movable mold and the static mold can tightly clamp the impeller body to avoid resin leakage during the injection molding process. At the same time, this design also enables the movable mold and the static mold to be separated smoothly during the demolding process without causing damage to the impeller body 1. In the mold opening state, the impeller body 1 can rotate on the static mold along the axial direction of the static mold toward the dynamic mold. During the mold opening process, the dynamic mold moves toward the side away from the static mold. At the same time, the static mold remains relatively fixed, so that the impeller body between the dynamic mold and the static mold can gradually break away from the restraint of the static mold as the dynamic mold moves, thereby realizing the automatic rotation demolding of the impeller. This design is the key to achieving self-rotation demolding. By rotating the impeller body, the impeller blades that were originally tightly combined with the mold can be gradually separated from the mold, thereby realizing demolding. In this process, since the impeller body rotates on the static mold, no additional demolding mechanism is required, which simplifies the mold structure and reduces processing costs.

[0020] Furthermore, the positive blade 4 and the reverse blade 5 form an angle α, and the positive blade 4 and the reverse blade 5 both have a corresponding self-locking angle θ, and the angle α between the positive blade 4 and the reverse blade 5 is greater than the self-locking angle θ corresponding to the positive blade 4 or the reverse blade 5. Specifically, in this embodiment, since the angle α between the positive blade 4 and the reverse blade 5 is greater than the self-locking angle θ corresponding to the positive blade 4 or the reverse blade 5, the positive blade and the reverse blade can better maintain their shape and position during the injection molding process, and are not prone to deformation or displacement. At the same time, since the angle α is greater than the self-locking angle θ, the positive blade and the reverse blade can be separated from the mold more smoothly during the demolding process, avoiding the problem of 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.

[0021] Furthermore, the impeller body 1 has two guide surfaces, each of which is provided with a plurality of wedge-shaped grooves 6 arranged in a circular array based on the axial center line of the impeller body 1, and each of the wedge-shaped grooves 6 has two inclined transition groove walls 7. Specifically, in the present embodiment, the setting of the wedge-shaped grooves 6 can realize that when the impeller is working, the wedge-shaped grooves 6 form an oil film on the upper and lower surfaces of the impeller during the rotation process by utilizing the principle of liquid dynamic pressure thrust bearing, thereby reducing the wear of the impeller and the pump cover of the pump body, improving the life of the electric fuel pump, and also reducing the noise problem caused by the direct friction between the impeller and the pump cover of the pump body; in order to realize the self-rotation demoulding of the impeller, the wedge-shaped grooves 6 need to add a spiral transition structure in the direction of rotation of the impeller demoulding to avoid interference between the impeller and the mold; and the setting of the wedge-shaped grooves 6 can optimize the flow path of the fluid, reduce the resistance and vortex 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 wall 7 allows the fluid to flow more smoothly through the wedge-shaped groove 6, avoiding the retention and scouring of the fluid at the groove wall, thereby extending the service life of the impeller body 1. In addition, the wedge-shaped grooves 6 and the transition groove wall 7 on the two guide surfaces cooperate with each other to form a more complex fluid channel, enhance the fluid dynamics characteristics of the impeller body 1, and enable the fuel pump to better adapt to different working conditions.

[0022] Furthermore, the inclination angle of the transition groove wall 7 is 10° to 30°. Specifically, by setting the transition groove wall 7, the fluid can flow more smoothly along the transition groove wall 7 during the self-rotation demolding of the impeller body 1, reducing the resistance of the fluid during the demolding process, and further improving the demolding efficiency. In addition, the inclination angle of the transition groove wall 7 is within the range of 10° to 30°, which can ensure that the fluid forms a stable oil film when flowing through the wedge groove 6 and the transition groove wall 7, reducing the scouring of the impeller body 1 and the mold by the fluid, thereby extending the overall service life. Moreover, it can make the fluid flow more smoothly when passing through the wedge groove 6, further reducing the retention and scouring of the fluid at the groove wall. The selection of the inclination angle is carefully calculated, and the range of 10° to 30° can not only ensure the smooth flow of the fluid, but also avoid the fluid pressure loss caused by excessive inclination.

[0023] Furthermore, the outer ring of the impeller body 1 protrudes to form an interference contact end 8, and the outer diameter of the interference contact end 8 exceeds the outer ring of the impeller body 1 by 0.02 to 0.06 mm on both sides of the interference contact end 8. Specifically, in this embodiment, the interference contact end 8 protrudes on the outer ring of the impeller body 1 can avoid the risk of the impeller hanging on the static mold during the self-rotation demoulding process, thereby realizing the fully automatic production of the impeller.

[0024] Furthermore, the two guide surfaces include a first guide surface 9 and a second guide surface 10, which are respectively formed on two opposite end surfaces of the impeller body 1, and the first guide surface 9 is concave to form an impeller glue opening 11, and the inner wall of the impeller glue opening 11 is arranged in an inclined structure, and the inner wall inclination angle of the impeller glue opening 11 is 5°. Specifically, in this embodiment, the depth of the impeller glue opening 11 needs to be controlled, and the inner wall inclination angle of the impeller glue opening 11 has a draft angle of 5° to reduce the interference with the mold core when the impeller is self-spinning and demolding.

[0025] Furthermore, the groove walls on both sides of the blade ring groove 2 of the impeller body 1 are opposite to each other and protrude toward the center line of the circumferential surface where the blade ring groove 2 is located to form an arc guide surface 12. Specifically, in this embodiment, by providing the arc guide surface 12 on the groove walls on both sides of the blade ring groove 2, the flow path of the fluid can be further optimized, and the vortex and resistance of the fluid in the blade ring groove 2 can be reduced, 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 provision of the arc guide surface 12 also enhances the durability of the impeller, reduces the wear caused by fluid scouring, and extends the service life of the impeller.

[0026] Furthermore, the impeller blade 3 has an oil inlet surface 13 and an oil outlet surface 14, and a guide plane 15 is provided on the oil outlet surface 14. Specifically, in the present embodiment, the positive blade 4 and the reverse blade 5 both have corresponding oil inlet surfaces 13 and oil outlet surfaces 14, and the oil inlet surfaces 13 and the oil outlet surfaces 14 are respectively formed on two opposite end surfaces of the positive blade 4 and the reverse blade 5. The guide plane 15 on the oil outlet surface 14 is designed to guide the flow direction of the fluid when it leaves the blade, to ensure that the fluid can flow out of the oil outlet surface 14 smoothly, and to further reduce vortex and resistance.

[0027] A guide plane 15 is provided on the oil outlet surface 14, and the guide plane 15 can effectively guide the flow of oil on the impeller blades 3, thereby improving the smoothness and efficiency of the oil flow. At the same time, the setting of the guide plane 15 can also reduce the retention time of the oil on the blade oil outlet surface 14, reduce the heat and wear generated by the long-term retention of the oil, and thus extend the service life of the impeller.

[0028] The oil outlet surface 14 of the positive blade 4 and the reverse blade 5 is composed of a straight surface (i.e., the guide plane 15) and a curved surface 16, wherein the length of the straight surface is greater than the length of the curved surface 16. This design is intended to optimize the flow characteristics of the oil. The length of the straight surface is greater than the curved surface, and this feature 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 eddies, making the oil flow smoother and reducing energy loss. At the same time, the existence of the curved surface 16 guides the oil to a smooth transition to a certain extent, further enhancing the stability of the circulation. In summary, the design of the oil outlet surface 14 of the positive blade 4 and the reverse blade 5 effectively improves the stability of the oil circulation through a reasonable combination of the straight surface and the curved surface.

[0029] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may 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 rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electric fuel pump impeller with a self-rotating demoulding structure, comprising an impeller body formed on an impeller mold, a blade ring groove is provided on the impeller body, and impeller blades are arranged in the blade ring groove, characterized in that: The impeller blades have positive blades and negative blades symmetrically arranged with the center line of the circumferential surface where the blade ring groove is located as a reference. The impeller blades are respectively inclined toward the center line of the circumferential surface where the blade ring groove is located from the notches on both sides of the blade ring groove. The impeller mold enters the blade ring groove from the direction of the positive blades and the negative blades respectively. The impeller body is demoulded by self-rotation on the mold during the demoulding process.

2. The electric fuel pump impeller with a self-rotating demoulding structure according to claim 1, characterized in that: The impeller mold includes a movable mold and a static mold, and the movable mold and the static mold are both provided with a movable mold connecting structure and a static mold connecting structure corresponding to the internal shape of the blade ring groove. The impeller body is placed between the movable mold and the static mold. When the movable mold is in an open state, the impeller body rotates on the static mold along the axial direction of the static mold toward the movable mold.

3. The electric fuel pump impeller with a self-rotating demoulding structure according to claim 1, characterized in that: The positive blade and the negative blade form an included angle α, and both the positive blade and the negative blade have a corresponding self-locking angle θ. The included angle α between the positive blade and the negative blade is greater than the corresponding self-locking angle θ of the positive blade or the negative blade.

4. The electric fuel pump impeller with a self-rotating demoulding structure according to claim 1, characterized in that: The impeller body has two guide surfaces, each of which is provided with a plurality of wedge-shaped grooves arranged in a circular array based on the axial center line of the impeller body, and each of the wedge-shaped grooves has two inclined transition groove walls.

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

6. The electric fuel pump impeller with a self-rotating demoulding structure according to claim 1, characterized in that: The outer ring of the impeller body is protruded to form an interference contact end, and the outer diameter of the interference contact end exceeds the outer ring of the impeller body and is located on both sides of the interference contact end by 0.02 to 0.06 mm.

7. The electric fuel pump impeller with a self-rotating demoulding structure according to claim 4, characterized in that: The two guide surfaces include a first guide surface and a second guide surface. The first guide surface is concave to form an impeller rubber opening. The inner wall of the impeller rubber opening is arranged in an inclined structure. The inclination angle of the inner wall of the impeller rubber opening is 5°.

8. The electric fuel pump impeller with a self-rotating demoulding structure according to claim 1, characterized in that: The groove walls on both sides of the blade ring groove of the impeller body are opposite to each other and protrude toward the center line of the circumferential surface where the blade ring groove is located to form an arc guide surface.

9. The electric fuel pump impeller with a self-rotating demoulding structure according to claim 1, characterized in that: The impeller blade has an oil inlet surface and an oil outlet surface, and a flow guide plane is arranged on the oil outlet surface.

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