Axial flow supercharging water pump impeller and machining method thereof

Abstract

The water pump impeller comprises a bottom shell and a top cover which are coaxially arranged, the bottom shell comprises a shell main body and at least three lower blades, the top cover comprises a cover main body and at least three upper blades, the shell main body comprises a center hole and a convex curved surface, and the convex curved surface comprises a convex curved surface and a convex curved surface. The lower blade spirally extends from the edge to the center hole along the convex curved surface, the cover main body comprises an axial flow hole and a concave curved surface, the lower blade and the upper blade are alternately arranged, and a curved flow channel is formed between the lower blade and the upper blade. Concave inserting grooves are formed in the positions, corresponding to the protruding inserting ribs, of the outwards-protruding curved surface and the inwards-concave curved surface, the groove bottoms of the inserting grooves partially protrude to form expansion protruding ribs, and the expansion protruding ribs and the expansion curved surface are complementary; the water pump impeller is welded and connected into a whole through an ultrasonic technology. The convex joint bars and the inserting grooves are matched for positioning, the expansion convex bars and the expansion curved surfaces are complementarily connected during ultrasonic welding, the combination area is enlarged, curved surface connection textures are formed, and the tensile strength is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water pump impellers, in particular to an axial-flow pressurized water pump impeller and a processing method thereof. BACKGROUND

[0002] A water pump impeller outputs liquid according to a preset pressure under the driving of a power and keeps the liquid flow rate stable. The water pump impeller can be made of plastic material and is welded by an ultrasonic welding process. For example, a document with publication number CN218542693U provides a water pump and a cleaning machine with a water pump impeller structure. A document with publication number CN114033743A provides an automotive electronic water pump impeller rotor.

[0003] The existing production process is as follows: an injection mold is used for processing, and the impeller is divided into a main body part with blades and a cover part. The cover part can be provided with a groove, and the blade end part is provided with a flat protruding rib. After the protruding rib is inserted into the groove and matched, it is formed by ultrasonic welding.

[0004] The existing structure is only suitable for welding of flat impellers. When facing impellers with large blade bending and distributed on curved surfaces, there are several key problems: 1. Difficulty in structure implementation: it is difficult to arrange the blades in the main body part, and it is difficult to match the design requirements of the curved surface. 2. Poor production quality: the cover part is welded by a single welding method. Not only is the deformation of the cover part large, but the connection strength of the welding part is lower than the forming strength of the blade of the main body part, which is prone to produce unqualified products, resulting in an increase in production scrap rate. 3. The combination area of the flat protruding rib and the groove is small, which affects the tensile strength of the blade, and therefore needs to be improved. SUMMARY

[0005] To overcome the problems in the related art, the present application provides an axial-flow pressurized water pump impeller and a processing method thereof to solve the technical problems of impeller production difficulty, large concentrated deformation of the welding part, and small tensile strength of the blade welding part.

[0006] According to a first aspect of the present application, an axial-flow pressurized water pump impeller is provided, which includes a bottom shell and a top cover arranged coaxially. The bottom shell includes a shell main body and at least three lower blades uniformly distributed. The top cover includes a cover main body and at least three upper blades. The shell main body includes a center hole and an outer convex curved surface gradually curved and protruding from the edge to the center hole. The lower blades extend spirally from the edge to the center hole along the outer convex curved surface. The cover main body includes an axial flow hole and an inner concave curved surface matched with the outer convex curved surface. The upper blades extend spirally from the edge to the axial flow hole along the inner concave curved surface. The lower blades and the upper blades are arranged alternately and form a curved flow channel therebetween. The lower blade and the upper blade are both locally protruded at the end to form a protruding plug, the end of at least part of the protruding plug is shaped as a recessed expansion curve, the outer convex curve and the inner concave curve are shaped as a recessed plug slot at the position of the protruding plug, the bottom of the plug slot is locally protruded to form an expansion convex rib, the expansion convex rib and the expansion curve are complementary; The water pump impeller is integrally connected by ultrasonic welding.

[0007] In an embodiment, the protruding plug includes a lower plug locally protruded from the end of the lower blade, a first plug and a second plug locally and separately protruded from the end of the upper blade, and the plug slot includes a third slot in the cover body, a first slot and a second slot in the shell body. The expansion convex rib includes a first convex rib in the second slot and a second convex rib in the third slot. The expansion curve includes a first curve in the lower plug and a second curve in the second plug, the surface area of the first curve is larger than the cross-sectional area of the lower plug, and the surface area of the second curve is larger than the cross-sectional area of the second plug. The first slot is adapted to the first plug, the second slot is adapted to the second plug, and the lower plug is adapted to the third slot.

[0008] In an embodiment, the rotation area of the first plug and the rotation area of the lower plug partially overlap or intersect, and the rotation area of the second plug and the rotation area of the lower plug partially overlap or intersect.

[0009] In an embodiment, the upper blade and the lower blade have the same curved shape, the upper blade includes a continuous flow guiding section, an extension section and a lifting section, the cross section of the flow guiding section is arc-shaped and protrudes towards one side of the axial hole, the lifting section intersects to the edge and the end is parallel to the center line of the axial hole, and the extension section extends along the inner concave curve.

[0010] In an embodiment, the thickness of the protruding plug is smaller than the thickness of the upper blade.

[0011] In an embodiment, the curved flow channel has a height difference in the axial direction between the inlet at one end of the axial hole and the outlet at the edge of the water pump impeller, and the cross-sectional area gradually increases from the axial hole to the edge.

[0012] In an embodiment, the expansion curve is an arc-shaped groove or a triangular groove or a trapezoidal groove.

[0013] In an embodiment, the protruding direction of the protruding plug is parallel to the center line of the axial hole, and adjacent upper blades and lower blades at least partially overlap on a projection plane, wherein the projection plane is a plane perpendicular to the axis.

[0014] According to a second aspect of the embodiments of the present application, a machining method of a water pump impeller is provided, the machining method of the water pump impeller is as described above, and the machining method comprises: aligning and assembling the bottom shell and the top cover to form an assembly; placing the water pump impeller on an ultrasonic device; controlling the ultrasonic device to press for 1s-2s under a pre-pressing pressure of 0.3 MPa-0.35 MPa, so that the upper blade and the outer convex surface are fitted, and the lower blade and the inner concave surface are fitted; controlling the ultrasonic device to output corresponding welding pressure and welding amplitude, so that the assembly combination part is ultrasonically welded to form the water pump impeller; taking out the water pump impeller.

[0015] In an embodiment, after the controlling the ultrasonic device to output corresponding welding pressure and welding amplitude, the machining method further comprises: reducing the pressure of the ultrasonic device to the pre-pressing pressure of 0.3 MPa-0.35 MPa; delaying the water pump impeller for 0.8s-1.2s under the pre-pressing pressure, so that the welding part is naturally cooled to below the glass transition temperature of the base material.

[0016] The technical scheme provided by the embodiments of the present application can have the following beneficial effects: the bottom shell and the top cover are both provided with blade structures, and the lower blades and the upper blades are alternately distributed, so that the welding parts are dispersed, the overall deformation is reduced, the pressure in each direction is balanced, the combination tightness of the welding parts is improved, and the welding effect is improved. The protruding insertion ribs and the insertion grooves are matched and positioned, and the expansion ribs and the expansion curved surfaces are complementarily connected during ultrasonic welding, not only expanding the combination area, but also forming curved connection textures, greatly improving the tensile strength. In addition, the alternately distributed lower blades and upper blades make the welding parts alternately distributed, and the blades on both sides of each welding part are integrally formed blade roots, so that the overall tensile strength of the impeller is improved. The blades extend in a spiral manner, and the spatial layout adjustment improves the output flow rate and the lift of the water pump impeller. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0018] Figure 1 is a structural schematic diagram of a water pump impeller according to an embodiment.

[0019] Figure 2 is an assembly schematic diagram of a bottom shell and a top cover according to an embodiment.

[0020] Figure 3is an assembly schematic view of the complementary protruding insert and the expanded protruding rib and the expanded curved surface in the insert slot according to an embodiment.

[0021] Figure 4 is a schematic view of an ultrasonic device according to an embodiment.

[0022] Figure 5 is a flow chart of a processing method according to an embodiment.

[0023] Figure 6 is a structural schematic view of a top cover according to an embodiment.

[0024] Figure 7 is a structural schematic view of a bottom shell according to an embodiment.

[0025] Figure 8 is a bottom view of a bottom shell according to an embodiment.

[0026] In the figure, bottom shell 10; cover body 11; upper blade 12; drainage section 121; extension section 122; lift section 123; axial flow hole 13; concave curved surface 14; protruding insert 15; first insert rib 151; second insert rib 152; lower insert rib 153; top cover 20; shell body 21; lower blade 22; center hole 23; outer convex curved surface 24; insert slot 25; first insert slot 251; second insert slot 252; third insert slot 253; expanded protruding rib 26; first protruding rib 261; second protruding rib 262; expanded curved surface 27; first curved surface 271; second curved surface 272; center insert 30; ultrasonic device 40; tooling table 50; arc-shaped positioning slot 51; center convex column 52. DETAILED DESCRIPTION

[0027] In the description of the present application, it needs to be understood that if the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation on the present application, for those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0028] As Figures 1 to 4As shown, the present application provides a kind of axial pressure water pump impeller, water pump impeller includes coaxially arranged bottom shell 10 and top cover 20, bottom shell 10 includes center hole 23, center hole 23 is fixedly installed with center insert 30, center insert 30 is used to connect motor or other power shaft, to realize water pump impeller driving rotation.Top cover 20 is provided with axial through-flow hole 13, axial through-flow hole 13 is used to guide liquid into water pump impeller, and output after accelerating and pressurizing by water pump impeller.The aperture size of axial through-flow hole 13 is greater than the aperture size of center hole 23, for guiding liquid into water pump impeller.

[0029] Bottom shell 10 includes shell body 21 and at least three pieces of evenly distributed lower blades 22, shell body 21 and lower blades 22 are integrally formed, and preferably, the number of lower blades 22 can be three, four or five pieces.Top cover 20 includes cover body 11 and at least three pieces of evenly distributed upper blades 12, upper blades 12 and cover body 11 are integrally formed.Upper blades 12 and lower blades 22 correspond, lower blades 22 and upper blades 12 are alternately arranged and form curved flow channel between them.

[0030] Water pump impeller is welded into an integral whole by ultrasonic process, the end of upper blade 12 and shell body 21 are welded to be an integral whole, the end of lower blade 22 and cover body 11 are welded to be an integral whole.Further preferably, the welding curve of upper blade 12 and the intersection line shape of lower blade 22 and shell body 21 are the same, based on the same principle, the welding curve of lower blade 22 and the intersection line shape of upper blade 12 and cover body 11 are the same.

[0031] Shell body 21 includes center hole 23 and outer convex curved surface 24 gradually curved and protruded from edge to center hole 23 direction, lower blade 22 extends along outer convex curved surface 24 from edge to center hole 23 direction, center hole 23 penetrates shell body 21 centrally, shell body 21 protrudes from edge to center direction, forming a horn-shaped curved surface structure.

[0032] Lower blade 22 is a curved surface thin wall structure, lower blade 22 extends along outer convex curved surface 24, edge of outer convex curved surface 24 extends spirally to center hole 23 direction, for example, lower blade 22 extends along outer convex curved surface 24 from edge to center hole 23 direction, helical pitch is 15 °-30 °, among them, 15 ° can be applicable to low-lift pump, 30 ° can be applicable to high-lift pump, optionally, the cross section of lower blade 22 is streamline, reducing fluid resistance.

[0033] The cover body 11 comprises an inner concave surface 14 matched with the outer convex surface 24, and the upper blades 12 extend spirally along the inner concave surface 14 from the edge to the axial flow hole 13. The upper blades 12 and the lower blades 22 are arranged alternately and separate the annular flow channel to form a plurality of curved flow channels. The upper blades 12 and the lower blades 22 are arranged alternately to achieve a greater bending angle and a pressurized flow channel, thereby improving the lift of the water pump impeller.

[0034] The lower blades 22 and the upper blades 12 are both locally protruded at the end to form a protruding plug 15. The outer convex surface 24 and the inner concave surface 14 are formed with a recessed plug slot 25 corresponding to the position of the protruding plug 15. The protruding plug 15 and the plug slot 25 are connected by plug-in connection, so that the end of the lower blade 22 can be attached to the inner concave surface 14, and the end of the upper blade 12 can be attached to the outer convex surface 24.

[0035] Further, at least part of the end of the protruding plug 15 is formed with a recessed expansion curved surface 27, and the bottom of the plug slot 25 is locally protruded to form an expansion convex rib 26, which is complementary to the expansion curved surface 27. When the protruding plug 15 and the plug slot 25 are plugged in place, the expansion curved surface 27 and the expansion convex rib 26 are in abutting cooperation. Preferably, the expansion curved surface 27 can be provided as an arc-shaped groove, a triangular groove or a trapezoidal groove to expand the bonding area of the protruding plug 15 and the plug slot 25, greatly improving the connection strength. For example, the expansion curved surface 27 is provided as an arc surface or a parabolic curved surface, and the radius of the arc surface is 1 mm-2 mm; or the expansion curved surface 27 is provided as a triangular groove, and the top angle can be 60°-90°; or the expansion curved surface 27 is provided as a trapezoidal groove, and the upper base width is 1 mm-1.5 mm, and the lower base width is 2-2.5 mm.

[0036] The surface area of the expansion curved surface 27 is greater than the cross-sectional area of the corresponding protruding plug 15, thereby expanding the bonding area, especially when the plug slot 25 is a groove structure. Preferably, the ratio of the surface area of the expansion curved surface 27 to the cross-sectional area of the protruding plug 15 is 1.3-1.5, thereby further improving the bonding strength.

[0037] Further, the surface of the protruding plug 15 or the plug slot 25 is provided with a welding line, which can improve the ultrasonic welding melting effect of the plug-in part to enhance the intermolecular bonding force. For example, the surface of the protruding plug 15 or the plug slot 25 is provided with a rough layer to enhance the intermolecular bonding force.

[0038] As shown in Figures 2 to 5 After the water pump impeller is produced by a mold, an ultrasonic device 40 is used to process the water pump impeller. The processing method comprises the following steps: Step S101, the bottom shell 10 and the top cover 20 are assembled to form an assembly; the bottom shell 10 and the top cover 20 are molded by injection molding, the bottom shell 10 and the top cover 20 are matched, and the protruding rib 15 of the lower blade 22 is inserted into the insertion slot 25 on the inner concave surface 14, while the protruding rib 15 on the upper blade 12 is inserted into the insertion slot 25 of the outer convex surface 24, and the lower blade 22 and the upper blade 12 are alternately arranged. Preferably, the assembly process can be aligned by a positioning auxiliary tool.

[0039] Step S102, the water pump impeller is placed in the ultrasonic device 40. The tooling table 50 is provided with an arc-shaped positioning groove 51 matched with the outer curved surface of the bottom shell 10, wherein the bottom shell 10 is a thin-walled structure, and correspondingly, the outer peripheral wall of the bottom shell 10 is provided with a recessed curved surface, the arc-shaped positioning groove 51 and the recessed curved surface are automatically centered and supported to improve the positioning accuracy of the recessed curved surface.

[0040] Further, the arc-shaped positioning groove 51 of the tooling table 50 is provided with an elastic buffer pad, which avoids scratching caused by hard contact between the assembly and the tooling table 50. Preferably, the arc-shaped positioning groove 51 is embedded with a thick fluororubber buffer layer, and the thickness of the thick fluororubber buffer layer can be set to 0.3mm-0.5mm. Wherein, the radius of the arc-shaped positioning groove 51 and the size of the outer peripheral wall and part of the bottom wall of the bottom shell 10 are basically the same, in order to accommodate and support the water pump impeller. Further preferably, the center of the arc-shaped positioning groove 51 is provided with a center protruding column 52, which is aligned and inserted into the center insert 30 and supports the center hole 23 to provide coaxial center positioning support.

[0041] Step S103, control the ultrasonic device 40 to press for 1s-2s under a pre-pressing pressure of 0.3MPa-0.35Mpa, so that the upper blade 12 and the outer convex surface 24 are fitted, and the lower blade 22 and the inner concave surface 14 are fitted. The center of the welding head is coaxial with the center hole 23 of the water pump impeller, and the welding head is controlled to press for 1s-2s under a pre-pressing pressure of 0.3MPa-0.35Mpa, so that the upper blade 12 and the outer convex surface 24 of the bottom shell 10, the lower blade 22 and the concave surface of the top cover 20 are tightly fitted, and at the same time, the expansion curved surface 27 and the corresponding expansion convex rib 26 are in contact with each other, avoiding the occurrence of fitting gap and the adverse effects of assembly out of position on the welding quality. The setting of the pre-pressing step can make the alternately distributed upper blade 12 and lower blade 22 be inserted in place, providing a high-precision basis for subsequent welding.

[0042] Step S104, control the ultrasonic device 40 to output corresponding welding pressure and welding amplitude, so that the assembly bonding site ultrasonic welding is formed into a water pump impeller. Adjust the parameters of the ultrasonic device 40, so as to carry out ultrasonic welding according to the characteristics and size of the product. Alternatively, the ultrasonic device 40 is started, the output welding pressure of the welding head is 0.35 MPa-0.4 MPa, the ultrasonic energy control is 110 J-120 J, the welding time is 0.8 s-1.2 s, and the welding head amplitude of the ultrasonic device 40 is 90%.

[0043] Alternatively, the welding head adopts an arc-shaped structure matched with the inner concave curved surface 14 of the top cover 20, and welding energy is uniformly transmitted to each welding site, so that synchronous welding of the contact sites such as the rib-in-slot and the blade-curved surface in the water pump impeller is realized.

[0044] Further preferably, during the welding process, the ultrasonic device 40 monitors the welding area temperature in real time through an infrared temperature sensor, which can detect the temperature of the welding site, so that the welding temperature of the welding site is maintained at 180℃-220℃, and the fluctuation range of the welding temperature is ≤±5℃.

[0045] In an optional embodiment, the welding head has a cooling channel inside, and cooling water is circulated in the cooling channel to avoid parameter drift caused by the temperature rise of the welding head. The cooling channel and the cooling water can be used to accurately control the temperature change of the welding head.

[0046] In another optional embodiment, the ultrasonic device 40 is provided with an air cooling assembly, which sends cold air towards the welding head to avoid parameter drift caused by the temperature rise of the welding head. The air cooling assembly can be provided with a temperature sensor to detect the temperature of the output cold air, so as to flexibly adjust the air speed and the temperature of the air according to the welding area temperature of the welding head, thereby accurately controlling the temperature change of the welding head.

[0047] Step S105, take out the water pump impeller. Lift the welding head, take out the curved impeller, complete the processing, and the next water pump impeller can be processed.

[0048] After the ultrasonic device 40 completes the welding of the water pump impeller in step S104, the water pump impeller after welding needs to be pressure maintained to stabilize the shape of the water pump impeller. The pressure maintaining pressure of the ultrasonic device 40 is less than the welding pressure, and preferably, the pressure maintaining pressure is between 0.3 MPa-0.35 MPa, and the time length of the delay pressure maintaining is 0.8 s-1.2 s, so that the welding of the water pump impeller is naturally cooled to below the glass transition temperature of the base material, so as to avoid internal stress caused by rapid cooling.

[0049] The bottom shell 10 and the top cover 20 are inserted and fitted with each other, and the protruding insert 15 and the insert slot 25 are correspondingly inserted. In an embodiment, the protruding insert 15 includes a lower insert 153 formed by partially protruding from the end of the lower blade 22, and the lower insert 153 is formed as a long protruding structure by protruding from the middle of the lower blade 22, so as to expand the welding length and the welding area. Correspondingly, the insert slot 25 includes a third insert slot 253 located at the cover body 11, and the third insert slot 253 is adapted to the shape of the lower insert 153.

[0050] Preferably, the third insert slot 253 is a groove structure, wherein the bottom of the third insert slot 253 forms a second protruding rib 262, and the end surface of the lower insert 153 is formed with a first curved surface 271, and the surface area of the first curved surface 271 is greater than the cross-sectional area of the lower insert 153.

[0051] As shown in Figure 2 , Figures 6 to 8 , the insert slot 25 includes a first insert slot 251 and a second insert slot 252 located at the shell body 21, and correspondingly, the protruding insert 15 includes a first insert 151 and a second insert 152 formed by partially and separately protruding from the ends of the upper blade 12, and the first insert 151 and the second insert 152 are arranged in a two-point welding structure and are respectively located at the top ends of the upper blade 12, so as to improve the positioning accuracy of the end of the upper blade 12, and to enable the end surface of the upper blade 12 to accurately fit the outer convex curved surface 24.

[0052] The first insert slot 251 and the second insert slot 252 are distributed on the outer convex curved surface 24, and optionally, the first insert slot 251 and the second insert slot 252 are both groove structures, the first insert slot 251 is adapted to the first insert 151, and the second insert slot 252 is adapted to the second insert 152, so as to improve the welding bonding area. Alternatively, the first insert slot 251 is a through hole structure, and the second insert slot 252 is a groove structure, so that the first insert 151 can be completely inserted into the first insert slot 251, and the upper blade 12 and the outer convex curved surface 24 are tightly fitted.

[0053] Further, the expansion protruding rib 26 includes a first protruding rib 261 located at the second insert slot 252, and the expansion curved surface 27 includes a second curved surface 272 located at the second insert 152, and the surface area of the second curved surface 272 is greater than the cross-sectional area of the second insert 152, the bonding area is large, and multi-point positioning can be achieved.

[0054] In the embodiment, the projections of the first insert 151, the second insert 152 and the lower insert 153 on the plane perpendicular to the axis are distributed in a staggered manner, which further improves the range of welding stagger on the basis of maintaining the insert positioning connection, thereby forming a multi-stage staggered welding fixing structure, improving the bonding strength and keeping the deformation balanced in all directions.

[0055] The end of the lower insert 153, the first insert 151 and the second insert 152 are shaped with a recessed expansion surface 27, the surface area of the welding joint is larger than the cross-sectional area of the insert, which greatly improves the joint strength. Optionally, the expansion surface 27 increases the joint area by 30-50% compared to the original insert.

[0056] In a preferred embodiment, the thickness of the raised insert 15 is less than the thickness of the upper blade 12, forming a stepped structure between the raised insert 15 and the upper blade 12. Therefore, the stepped surface between the raised insert 15 and the upper blade 12, the end surface of the upper blade 12, the side surface and end surface of the raised insert 15 are integrated with the outer convex surface 24 under the action of ultrasonic waves.

[0057] Based on the same principle, the thickness of the raised insert 15 is less than the thickness of the lower blade 22, and the lower blade 22 is integrated with the inner concave surface 14.

[0058] The raised direction of the raised insert 15 is parallel to the center line of the axial flow hole 13, and the top cover 20 and the bottom shell 10 are assembled by inserting the raised insert 15 into the insertion slot 25 to improve the assembly precision. The upper blade 12 is a curved surface structure, the raised insert 15 is arranged at the top end of the upper blade 12, and is parallel to the center line of the axial flow hole 13. An angle is formed between the raised insert 15 and the curved surface of the upper blade 12, so that the curved surface of the upper blade 12 can provide multi-directional support components, further improving the joint strength of the upper blade 12 and the bottom shell 10.

[0059] Further, adjacent upper blades and lower blades at least partially overlap in the projection plane, wherein the projection plane is a plane perpendicular to the axis. The upper blade and the lower blade partially overlap in the projection plane, and the existing injection mold is difficult to process and form at one time, and the upper blade and the lower blade partially overlap in the projection plane close to the axial flow hole, thereby improving the peripheral structural strength of the axial flow hole, so that the water pump impeller can withstand greater liquid impact force, further improving the lift.

[0060] The water pump impeller rotates around the axis of the central hole 23, and the first insert 151, the second insert 152 and the lower insert 153 correspond to the rotation track formed by rotation. Among them, the rotation area of the first insert 151 and the rotation area of the lower insert 153 partially overlap or intersect, and the rotation area of the second insert 152 and the rotation area of the lower insert 153 partially overlap or intersect. The rotation area of the first insert 151 near the center of the blade and the rotation area of the lower insert 153 partially overlap or intersect, and the rotation area of the second insert 152 near the center of the blade and the rotation area of the lower insert 153 partially overlap or intersect, so that the protruding insert 15 forms a cross support structure when the impeller rotates, and the connection stability of the bottom shell 10 and the top cover 20 is enhanced. As a preferred, the overlap degree of the rotation area of the first insert 151 and the rotation area of the lower insert 153 is 0-50%, and the overlap degree of the rotation area of the second insert 152 and the rotation area of the lower insert 153 is 0-50%. Among them, the length of the lower insert 153 is greater than the length of the first insert 151, wherein the overlap degree of the rotation area of the first insert 151 and the rotation area of the lower insert 153 is 0, then the edges of the rotation areas of the two intersect. When the overlap degree of the rotation area of the first insert 151 and the rotation area of the lower insert 153 is 50%, then half of the rotation area of the first insert 151 and the rotation area of the lower insert 153 intersect. The second insert 152 can also be understood by reference.

[0061] The overlap degree of the rotation area can change the welding and inserting range of the water pump impeller, and also can realize internal stress adjustment and improve rotation stability.

[0062] As shown in Figures 6 to 8 The upper blade 12 and the lower blade 22 have the same curved shape, and only the structure of the inserted part is different. Among them, the upper blade 12 includes a continuous flow guiding section 121, an extension section 122 and a lifting section 123, the cross section of the flow guiding section 121 is arc-shaped and protrudes towards the side of the axial hole 13, which can guide the fluid to enter the flow passage smoothly and avoid the loss caused by the impact of the fluid on the blade. Optionally, the inlet of the flow guiding section 121 is within the flow guiding range of the axial hole 13, and the flow guiding section 121 is arranged in an arc-shaped structure, which can not only enhance the structural strength of the flow guiding section 121 and have appropriate elastic internal stress, but also reduce the noise caused by the impact of the straight wall on the liquid, and has good noise reduction effect. The arc-shaped protruding part of the flow guiding section 121 is directed to the inlet direction of the axial hole 13, and the curved channel conforms to the rotation direction of the water pump impeller, so as to cut into the liquid flow.

[0063] The lifting section 123 intersects at the edge and its end is parallel to the centerline of the axial flow hole 13, which can efficiently push the fluid to the edge of the impeller and increase the pump head. The lifting section 123 has a straight wall structure, and its end intersects with the edge of the pump impeller, forming a tangential liquid outlet structure, which can stabilize the liquid outlet direction and increase the liquid outlet velocity. Preferably, the shell body 21 and the cover body 11 form two relatively parallel planes at the output position of the curved flow channel.

[0064] The extension section 122 connects the lifting section 123 and the drainage section 121. The extension section 122 extends obliquely along the concave curved surface 14, and the angle of inclination matches the curvature of the concave curved surface 14 to ensure a smooth transition of the flow channel. The curved surface of the extension section 122 gradually straightens and smoothly intersects with the arc surface of the drainage section 121 to the lifting section 123, which can both guide the smooth flow of liquid and maintain structural stability.

[0065] Furthermore, the upper blade 12 intersects with the concave curved surface 14. The upper blade 12 gradually bends from the edge of the pump impeller toward the axial flow hole 13. The upper blade 12 is straight at the edge of the pump impeller. The bending angle of the upper blade 12 gradually bends into an arc-shaped surface from the straight edge toward the axial flow hole 13, thereby gradually forming a liquid acceleration and guiding structure and directional output.

[0066] In one embodiment, the curved flow channel has an axial height difference between its inlet at one end of the axial flow hole 13 and its outlet at the edge of the pump impeller, and its cross-sectional area gradually increases from the axial flow hole 13 towards the edge. The shape of the curved flow channel is adjusted according to the shapes of the concave curved surface 14, the convex curved surface 24, the upper blade 12, and the lower blade 22. The curved flow channel has an axial height difference, and the liquid enters from the axial flow hole 13 and exits in a spiral direction, achieving acceleration in both the axial and radial directions, greatly increasing the liquid's outlet velocity and outlet pressure, and thus increasing the head.

[0067] It should be understood that this application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of this application and include common knowledge or customary techniques in the art that are not disclosed in this invention.

Claims

1. An axial flow booster water pump impeller, the water pump impeller comprising a bottom shell and a top cover coaxially arranged, characterized in that: The bottom shell includes a shell body and at least three evenly distributed lower blades, and the top cover includes a cover body and at least three upper blades; The shell body includes a central hole and an outwardly convex surface that gradually curves and protrudes from the edge toward the central hole. The lower blade extends spirally from the edge toward the central hole along the outwardly convex surface. The cover body includes an axial flow hole and an inwardly concave surface that matches the outwardly convex surface. The upper blade extends spirally from the edge toward the axial flow hole along the inwardly concave surface. The lower blade and the upper blade are alternately arranged and a curved flow channel is formed between them. Both the lower blade and the upper blade have raised inserts at their ends. At least a portion of the raised inserts have recessed expansion surfaces at their ends. The outer and inner convex surfaces have recessed insertion grooves at the positions corresponding to the raised inserts. The bottom of the insertion grooves has raised ribs at their ends. The expansion ribs and the expansion surfaces are complementary. The water pump impeller is welded together as a single unit using ultrasonic welding.

2. The water pump impeller according to claim 1, characterized in that, The protruding insert includes a lower insert forming a partial protrusion from the end of the lower blade, and a first insert and a second insert forming a partial, spaced protrusion from the end of the upper blade. The insertion groove includes a third slot located in the cover body, and a first slot and a second slot located in the shell body. The expansion rib includes a first rib located in the second slot and a second rib located in the third slot. The expansion surface includes a first surface located on the lower insert and a second surface located on the second insert, wherein the surface area of ​​the first surface is greater than the cross-sectional area of ​​the lower insert, and the surface area of ​​the second surface is greater than the cross-sectional area of ​​the second insert. The first slot is adapted to the first insert bar, the second slot is adapted to the second insert bar, and the lower insert bar is adapted to the third slot.

3. The water pump impeller according to claim 2, characterized in that, The rotation area of ​​the first insert bar and the rotation area of ​​the lower insert bar partially overlap or intersect, and the rotation area of ​​the second insert bar and the rotation area of ​​the lower insert bar partially overlap or intersect.

4. The water pump impeller according to claim 2, characterized in that, The upper and lower blades have the same curved surface shape. The upper blade includes a continuous flow-guiding section, an extension section, and a lifting section. The cross-section of the flow-guiding section is arc-shaped and protrudes towards the axial flow hole. The lifting section intersects at the edge and its end is parallel to the center line of the axial flow hole. The extension section extends obliquely along the concave curved surface.

5. The water pump impeller according to claim 4, characterized in that, The thickness of the protruding rib is less than the thickness of the upper blade.

6. The water pump impeller according to claim 4, characterized in that, The curved flow channel has an axial height difference between its inlet at one end of the axial flow hole and its outlet at the edge of the pump impeller, and its cross-sectional area gradually increases from the axial flow hole toward the edge.

7. The water pump impeller according to claim 2, characterized in that, The expansion surface is an arc-shaped groove, a triangular groove, or a trapezoidal groove.

8. The water pump impeller according to claim 1, characterized in that, The protruding direction of the protruding rib is parallel to the center line of the axial flow hole, and the adjacent upper and lower blades overlap at least partially on the projection plane, wherein the projection plane is a plane perpendicular to the axis.

9. A method for machining a water pump impeller, characterized in that, The method for machining a water pump impeller as described in any one of claims 1 to 8 includes: Align and assemble the bottom shell and top cover to form an assembly; Place the water pump impeller in the ultrasonic device; The ultrasonic device is controlled to press for 1-2 seconds under a pre-pressure of 0.3MPa-0.35MPa to make the upper blade and the outward convex curved surface fit together, and the lower blade and the inward concave curved surface fit together. The ultrasonic equipment is controlled to output corresponding welding pressure and welding amplitude so that ultrasonic welding is completed at the joint of the assembled parts to form a water pump impeller. Remove the water pump impeller.

10. The processing method according to claim 9, characterized in that, The ultrasonic device is controlled to output corresponding welding pressure and welding amplitude, and then: Reduce the pressure of the ultrasonic device to a holding pressure of 0.3 MPa-0.35 MPa; The water pump impeller is subjected to a pressure delay of 0.8 s - 1.2 s to allow the weld to cool naturally to below the glass transition temperature of the substrate.

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