A design method for a blade that can reduce operating resistance

Abstract

The application discloses a design method of a blade capable of reducing operation resistance, relates to the technical field of fan blades, and comprises a blade body, wherein a blade working surface and a blade leading edge curve are arranged on the blade body; a sketch distribution curve group and a concave hole array region are arranged on the blade working surface; the concave hole array region is surrounded by the periphery of the sketch distribution curve group; a plurality of concave holes are arranged in the concave hole array region; the sketch distribution curve group comprises a plurality of sketch distribution curves; and the concave holes are arranged on the sketch distribution curves. The application is suitable for all blades capable of adding concave holes, and the concave holes are arranged in an array on the blade to optimize the structure. On the basis of the current blade, the method can be implemented by simply modifying a mold, has low cost, improves the blade efficiency, reduces the pressure difference before and after the blade, further reduces the resistance of the blade itself, improves the performance of the impeller, has wide universality, has simple concave hole structure, simple process, remarkable blade working effect, and wide application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fan blades, in particular to a design method of a blade capable of reducing operating resistance. BACKGROUND

[0002] The fan blade is one of the core components of the fan, and the design of the fan blade will directly affect the performance and benefits of the fan.

[0003] In the current heating and axial flow fan industry, the existing fan blades mostly change the upper and lower heights of the blades, the blade surface, the outer diameter of the blades and other means to optimize the performance of the blades, and the structure of the blades is mostly not universal, only suitable for some cases, and difficult to meet the requirements of performance improvement of all blade types, and the means to reduce air resistance and aerodynamic noise are relatively few, and lack of theoretical basis and actual test data, and are not universal, and the blades have their own resistance, and the efficiency is not high.

[0004] In addition, directly modifying the blade surface can obtain relatively good performance, but the development process is time-consuming and laborious, and a large amount of time, effort and capital investment is required for blade modeling, simulation optimization, hand plate testing and other processes, and it is difficult to meet the requirements of rapid performance improvement, and there are problems of high cost and complex structure. SUMMARY

[0005] In order to solve the problems in the background art, the present application provides a design method of a blade capable of reducing operating resistance. A plurality of concave holes arranged in an array are provided on the blade to optimize the structure, which is suitable for all blades capable of adding concave holes, and can be simply modified based on the current blade to achieve low cost. The present application can improve the efficiency of the blade by arranging the concave holes on the sketch distribution curve, and further improve the efficiency of the blade by 2-3 points based on the original efficiency of the blade. The present application can reduce the resistance of the blade itself, reduce the pressure difference before and after the blade, and further reduce the resistance of the blade itself, and improve the performance of the impeller. The present application is suitable for most blades with a thickness of more than 1.5mm, especially plastic blades, and has wide universality. The concave hole structure is simple, and can be manufactured by mold or other processing methods, and the process is simple, the actual working effect of the blade is remarkable, and the application is wide.

[0006] In order to achieve the above purpose, the present application is realized by the following technical scheme:

[0007] A blade capable of reducing operating resistance, comprising a blade body, wherein a blade working surface and a blade leading edge curve are arranged on the blade body, a grass sketch distribution curve group and a hollow array region are arranged on the blade working surface, the hollow array region is enclosed by the periphery of the grass sketch distribution curve group, a plurality of hollows are arranged in the hollow array region in an array, and the grass sketch distribution curve group comprises a plurality of grass sketch distribution curves, and the hollows are arranged on the grass sketch distribution curves.

[0008] Preferably, the plurality of grass sketch distribution curves comprise an inner peripheral curve, an outer peripheral curve, and a first distribution curve and an nth distribution curve, which are offset from the blade leading edge curve, and the hollow array region is enclosed by the first distribution curve, the inner peripheral curve, the nth distribution curve, and the outer peripheral curve in sequence.

[0009] Preferably, the interval distance between any two adjacent grass sketch distribution curves is the same, and the interval distance between any two adjacent hollows is the same.

[0010] Preferably, the first distribution curve is provided with a first distribution curve starting point.

[0011] Preferably, the radii of the plurality of hollows are the same.

[0012] Preferably, any three adjacent hollows are not on the same rotational circumferential trajectory of the blade.

[0013] Preferably, the depth of the hollows is less than or equal to 1 mm.

[0014] A design method of a blade capable of reducing operating resistance, comprising the following steps:

[0015] Step S1, establishing a hollow grass sketch distribution curve C1: offsetting the blade leading edge curve by d unit distances to obtain a first distribution curve, offsetting the blade leading edge curve by 2d unit distances to obtain a second distribution curve, and then offsetting in sequence to obtain an nth distribution curve; sketching an inner peripheral curve and an outer peripheral curve, deleting the redundant distribution curves inside the inner peripheral curve, and deleting the redundant distribution curves outside the outer peripheral curve to form distribution curves with uniform length changes;

[0016] Step S2, copying and offsetting the blade working surface curve: copying the blade working surface curve as F0, and offsetting F0 by y surface distances to obtain an offset surface F1;

[0017] Step S3, creating a projection curve C2: using a projection function to project the grass sketch distribution curve to F1 to obtain a projection curve C2;

[0018] Step S4, creating a reference surface F: creating a reference surface using the first distribution curve after projection and the starting point close to the blade handle side as a reference;

[0019] Step S5, create the first hollow feature: create a rotational subtraction feature on the reference surface F, complete the rotational subtraction feature by rotating a semicircular section 360 degrees, and generate a hollow left after being cut on the blade;

[0020] Step S6, array the first hollow in step S5: select a curve distribution array type, select a sketch distribution curve C1, set the interval d, select the follow-up surface shape F0, array the direction along the surface direction, follow the curve direction, and remove the hollow features distributed on the outside, and complete the array of the hollow features after determination.

[0021] Preferably, in step S5, the first hollow feature is created: a rotational subtraction feature is created on the reference surface F, the starting point of the first distribution curve after projection is taken as a reference and as a center of a circle, a closed semicircle is drawn with a radius R, and the rotational subtraction feature is completed by rotating a semicircular section 360 degrees, and the first hollow left after being cut on the blade is generated.

[0022] Preferably, in step S6, the hollow depth is x, the offset surface F1 offset distance is y, the cutting radius R, the hollow radius r, and the approximate relationship of the four is: R=x+y, R 2 =y 2 +r 2 ; the hollow depth x is less than or equal to 1 mm.

[0023] Compared with the prior art, the present application has the following advantages:

[0024] The present application optimizes the structure by providing a plurality of hollows arranged in an array on the blade, is suitable for all blades that can add hollows, and can be realized by simply modifying the mold on the basis of the current blade, and has low cost.

[0025] The present application can improve the efficiency of the blade by arranging the hollows on the sketch distribution curve, and can further improve the efficiency of the blade by 2-3 points on the basis of the original efficiency of the blade.

[0026] The present application can reduce the resistance of the blade itself, reduce the pressure difference before and after the blade, and thus reduce the resistance of the blade itself, and improve the performance of the impeller.

[0027] The present application can be applied to most blades with a thickness of more than 1.5 mm, especially plastic blades, and has wide applicability.

[0028] The present application can be applied to most blades with a thickness of more than 1.5 mm, especially plastic blades, and has wide applicability. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in these drawings without creative labor.

[0030] Figure 1 is the overall structure diagram of the blade which can reduce the running resistance of an embodiment of the present application;

[0031] Figure 2 is the structure diagram of the sketch distribution curve group of an embodiment of the present application;

[0032] Figure 3 is the structure diagram of the concave hole of an embodiment of the present application;

[0033] Figure 4 is the structure diagram of the concave hole distribution relationship of an embodiment of the present application.

[0034] In the figure: 1, concave hole, 2, blade working surface, 3, first distribution curve, 31, starting point of the first distribution curve, 4, nth distribution curve, 5, inner peripheral curve, 6, outer peripheral curve, 7, blade leading edge curve. DETAILED DESCRIPTION

[0035] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0036] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0037] In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0038] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or communicated with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] Reference Figures 1-4 , for the embodiment of the blade of the present application which can reduce the operating resistance, in the embodiment, a blade body is included, the blade body is provided with a blade working surface 2, a blade leading edge curve 7, the blade working surface 2 is provided with a sketch distribution curve group, a hollow array area, the hollow array area is surrounded by the periphery of the sketch distribution curve group, a plurality of hollows 1 are arranged in the hollow array area, the sketch distribution curve group includes at least two sketch distribution curves, and the hollow 1 is arranged on the sketch distribution curve. In this embodiment, by providing a plurality of hollows 1 arranged in an array on the blade, the structure is optimized, which is suitable for all blades that can add hollows 1, and can be realized by simply modifying the mold on the basis of the current blade, which can reduce the resistance of the blade itself, reduce the pressure difference before and after the blade, thereby reducing the resistance of the blade itself, improving the performance of the impeller, and being suitable for most blades with a thickness of more than 1.5 mm, especially plastic blades, which has wide universality, simple hollow 1 structure, and can be manufactured by mold or other processing methods, and the process is simple; by arranging the hollow 1 on the sketch distribution curve, the efficiency of the blade can be improved, and the efficiency of the blade can be further improved by 2-3 points on the basis of the original efficiency of the blade.

[0040] In this embodiment, the plurality of sketch distribution curves include an inner peripheral curve 5, an outer peripheral curve 6, and a first distribution curve 3 and an n-th distribution curve 4 which are offset from the blade leading edge curve 7, and the hollow array area is surrounded by the first distribution curve 3, the inner peripheral curve 5, the n-th distribution curve 4, and the outer peripheral curve 6 in sequence.

[0041] In this embodiment, the interval distance between any two adjacent sketch distribution curves is the same, and the interval distance between any two adjacent hollows 1 is the same.

[0042] In this embodiment, the first distribution curve 3 is provided with a first distribution curve starting point 31.

[0043] In this embodiment, the radii of the at least two hollows 1 are the same.

[0044] In the embodiment, any three adjacent said hollows 1 are not on the same rotating circumferential trajectory of the blade.

[0045] In the embodiment, the depth of the hollow 1 is less than or equal to 1 mm.

[0046] In the embodiment, as shown in Figure 4 The distance between the two adjacent hollows 1 is d, that is, the distance between the hollow 1 and the nearby hollow 1 is d;

[0047] The distribution position of the hollow 1: the hollow 1 is distributed on the projected sketch distribution curve, and after the blade starts to rotate, the hollow 1 and the hollow 1 on the nearest two sketch distribution curves are not on the same rotating path, as shown in Figure 4 Most of the hollows 1 are not distributed on the same circle; the hollow 1 needs to be away from the position of the bottom of the sawtooth groove to avoid stress concentration and fracture.

[0048] The application also provides a design method of a blade capable of reducing operating resistance, comprising the following steps:

[0049] Step S1, establishing a hollow sketch distribution curve C1: offsetting the blade leading edge curve by d unit distances to obtain the first distribution curve, offsetting the blade leading edge curve by 2d unit distances to obtain the second distribution curve, and then sequentially offsetting to obtain the nth distribution curve; deleting the redundant distribution curves inside the inner periphery curve and outside the outer periphery curve to form the distribution curves with uniform length changes;

[0050] Step S2, copying and offsetting the blade working surface curve: copying the blade working surface curve as F0, and offsetting F0 by y surface distances to obtain the offset surface F1;

[0051] Step S3, creating a projection curve C2: using the projection function to project the sketch distribution curve to F1 to obtain the projection curve C2;

[0052] Step S4, creating a reference surface F: creating a reference surface based on the first distribution curve after projection and the starting point close to the handle side as the reference;

[0053] Step S5, creating the first hollow feature: creating a rotating cutting feature on the reference surface F, rotating the semicircular section by 360 degrees to complete the rotating cutting feature, and generating the hollow left after cutting on the blade;

[0054] Step S6, arraying the first hollow in step S5: selecting the curve distribution array type, selecting the sketch distribution curve C1, setting the interval d, selecting the following surface shape F0, arraying in the direction of the surface and the curve, and selecting the hollow features on the outer side to be removed, and determining the array of the hollow features.

[0055] In the embodiment, the step S5, the first recess feature is created: a rotating cutting feature is created on the reference surface F, taking the starting point of the projected first distribution curve as the reference and as the center of the circle, a closed semicircle with radius R is drawn, and the rotating cutting feature is completed by rotating the semicircle section by 360 degrees, so that the first recess is left on the blade after being cut.

[0056] In the embodiment, in the S6, the recess depth is x, the offset distance of the offset surface F1 is y, the cutting radius is R, the recess radius is r, and the approximate relationship of the four is: R=x+y, R2=y2+r2; the recess depth x≤1mm.

[0057] In the embodiment, the actual effect generated after the recess 1 is arranged on the blade is shown in the following table:

[0058]

[0059]

[0060]

[0061] The above tests are tests conducted on the same day, and environmental factors are excluded as much as possible to affect the test results.

[0062] In terms of actual test effect, the blade working surface with the recess can improve the efficiency of the fan blade to a certain extent, and the numerical value is 2-3% efficiency improvement, and the noise performance changes little and can be ignored.

[0063] In the embodiment, by arranging a plurality of recesses 1 in an array on the blade, the structure is optimized, which is suitable for all blades that can add the recess 1, and the current blade can be simply modified to realize, and the cost is low;

[0064] By arranging the recess on the sketch distribution curve, the efficiency of the blade can be improved, and the efficiency of the blade can be further improved by 2-3 points on the basis of the original efficiency of the blade;

[0065] By arranging a plurality of recesses 1 in an array on the blade, the resistance of the blade itself can be reduced, the pressure difference before and after the blade can be reduced, and the resistance of the blade itself can be reduced, and the performance of the impeller can be improved;

[0066] By arranging a plurality of recesses 1 in an array on the blade, it can be applied to most blades with a thickness of more than 1.5mm, especially plastic blades, and is widely applicable.

[0067] The present application can be widely applied by arranging a plurality of recesses 1 in an array on the blade, the recess 1 structure is simple, can be manufactured by mold or other processing methods, the process is simple, the actual working effect of the blade is remarkable, and is widely applied.

[0068] Any combination of the technical features in the above-described embodiments can be made. For the sake of brevity, the foregoing description is not intended to be exhaustive or to be limited to the precise embodiments described. Modifications or variations are possible in light of the above teachings. The embodiments were chosen and described in order to best illustrate the principles of the application and its practical application and to thereby enable others skilled in the art to best utilize the application.

[0069] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A design method for a blade with reduced operating resistance, the blade comprising a blade body, the blade body being provided with a blade working surface (2), a blade leading edge curve (7), the blade working surface (2) being provided with a sketch distribution curve group, a cavity array region, the cavity array region being enclosed by the periphery of the sketch distribution curve group, a plurality of cavities (1) being arranged in the cavity array region, the sketch distribution curve group comprising a plurality of sketch distribution curves, the cavities (1) being arranged on the sketch distribution curves, comprising the following steps: characterized in that Step S1, establishing a cavity sketch distribution curve C1: offsetting the blade leading edge curve by d unit distances to obtain a first distribution curve, offsetting the blade leading edge curve by 2d unit distances to obtain a second distribution curve, and then sequentially offsetting to obtain an nth distribution curve; sketching an inner and outer peripheral curve, deleting the excess distribution curves inside the inner peripheral curve, and deleting the excess distribution curves outside the outer peripheral curve to form distribution curves with uniform length changes; Step S2, copying and offsetting the blade working surface curve: copying the blade working surface curve as F0, and offsetting F0 by y curve distances to obtain an offset curve F1; Step S3, creating a projection curve C2: using a projection function, projecting the sketch distribution curve to F1 to obtain a projection curve C2; Step S4, creating a reference surface F: creating a reference surface using the first distribution curve after projection and the starting point close to the handle side as a reference; Step S5, creating a first cavity feature: creating a rotational cutting feature on the reference surface F, rotating a semicircular cross section 360 degrees to complete the rotational cutting feature, and generating a cavity left after cutting on the blade; Step S6, arraying the first cavity in step S5: selecting a curve distribution array type, selecting the sketch distribution curve C1, setting a pitch d, selecting a follow-up surface shape F0, arraying in a follow-up surface direction, following a curve direction, and selecting to remove cavity features that are too far outside, and determining to complete the array of cavity features. In step S5, creating a first cavity feature: creating a rotational cutting feature on the reference surface F, taking the starting point of the first distribution curve after projection as a reference and as a center, drawing a closed semicircle with a radius R, rotating a semicircular cross section 360 degrees to complete the rotational cutting feature, and generating a first cavity left after cutting on the blade.

2. The method of designing a blade with reduced operating drag according to claim 1, wherein ​ 3. The method of designing a blade with reduced operating drag according to claim 1, wherein In the S6, the recess depth is x, the offset distance of the offset surface F1 is y, the cutting radius is R, the recess radius is r, and the approximate relationship of the four is: R = x + y, R 2 = y 2 + r 2 ; the recess depth x ≤ 1 mm.

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