CN220319900U - A sheet metal centrifugal wind wheel - Google Patents

Abstract

The utility model discloses a sheet metal centrifugal wind wheel, which comprises a wheel disc (200), a wheel cover (300) and a plurality of blades (100), wherein the blades (100) are arranged between the wheel disc (200) and the wheel cover (300), and the blades (100) comprise an inlet edge (1), an outlet edge (2), a blade root (3) and a blade top (4), and are characterized in that: the angle position bending part (101) is formed on the angle position of the top of the outlet edge (2), the angle position bending part (101) bends towards the center of the wind wheel rotating shaft L, the blade structure model is stabilized, the rebound effect is restrained, the deviation between the actual blade molded line and the designed blade molded line is reduced, the air flow angle of the blade after rebound is ensured to conform to the original design, the number of times of correcting the die is reduced, the manufacturing cost and the die cost are saved, uncontrollable factors are reduced, and the final blade performance and the finished product delivery period are ensured.

Description

A sheet metal centrifugal wind wheel

Technical areas:

The utility model relates to a sheet metal centrifugal wind wheel.

Background technique:

As shown in Figure 1, the existing sheet metal backward centrifugal wind wheel consists of a disk 1a, a wheel cover 2a, and a number of blades 3a. The blades are formed by the sheet metal stamping process. After the stamping is completed, there will be rebound due to the elastic properties of the material. This phenomenon will cause the actual blade profile to deviate from the originally designed blade profile. The detailed description is as follows:

The blade of a centrifugal wind rotor is a key component, which directly affects the efficiency of the wind rotor, and the blade profile is an important geometric concept that characterizes the performance of the wind rotor blade. For centrifugal wind rotors, cut the rotor using any plane perpendicular to the rotation axis near the bottom of the rotor, and the blade cross section can be obtained, as shown in Figure 2. Countless blade profiles can be drawn within the blade cross section. The inscribed circle of the line and the line connecting the centers of all inscribed circles is the blade profile line (or blade center line), as shown in Figure 3. The blade profile line is the basic geometric unit of the blade, and the blade can be regarded as countless cross-sections. The different blade lines on the blade are accumulated from the blade root to the blade tip.

As shown in Figure 4, the definition of blade geometric parameters: the end point of the air inflow direction is the starting point of the blade profile line, and the end point of the air leaving direction is the end point of the blade profile line. According to the concepts of absolute speed, relative speed and implicated speed in theoretical physics, it can be seen that the air will make relative motion in the wind wheel along the blade profile. Using the earth as the reference of the absolute coordinate system and decomposing the absolute velocity vector of the air according to the parallelogram theorem, we can easily draw the starting point and end point of the blade profile line and the relationship between each velocity vector in the process. The air velocity vector at the starting point and end point of the blade profile directly determines the blade's performance. For the starting point of the blade profile line: C1 is the absolute speed of the blade inlet airflow, W1 is the relative speed of the blade inlet airflow, and U1 is the implicated speed of the starting point of the blade profile line, that is, the circumferential speed at that point. For the end point of the blade profile line: C2 is the absolute speed of the blade outlet airflow, W2 is the relative speed of the blade outlet airflow, and U2 is the implicated speed at the end point of the blade profile line, that is, the circumferential speed at that point. Then: the reverse angle between W1 and U1 is the blade inlet angle; the reverse angle between W2 and U2 is the blade outlet angle. Blade rebound phenomenon: Blades are made by sheet metal stamping process. Sheet metal stamping is a metal processing method. It is based on the plastic deformation of metal. It uses molds and stamping equipment to exert pressure on the sheet metal to cause the sheet metal to produce Plastic deformation or separation to obtain parts (stamping parts) with certain shapes, sizes and properties. Due to the elastic modulus (inherent physical property) of the sheet material, there is internal stress in the stamped parts after plastic deformation. After the stamped parts have been left standing for a period of time, the internal stress will be released, and where the amount of plastic deformation is small, there will be a tendency to "go back" to the original state of the sheet. This phenomenon is called springback. For blades made by sheet metal stamping process, their plastic deformation is small and the rebound phenomenon is very obvious. The springback phenomenon causes the blade shape to deviate from the designed shape. Essentially, the blade profile deviates from the original design.

As shown in Figure 5, the dotted blade profile line is the designed shape, and the solid blade profile line represents the shape after rebound. Combined with the above definition of blade geometric parameters, it can be seen that the absolute positions of the starting point and end point of the blade profile change after rebound. The macroscopic manifestation is that the blade inlet angle becomes smaller and the blade outlet angle becomes larger.

A larger blade exit angle will increase the power of the wind rotor beyond the original design range. Although the increase in working capacity is a positive change for the properties of the wind wheel, it also means that the input and output power of the motor equipped with the wind wheel will also increase. For the established design goals, the additional input and output power may exceed the allowable limit range of the motor, causing a series of deteriorating problems such as excessive temperature rise of the motor, reduction of motor output efficiency, accelerated failure of motor parts, etc., which will ultimately manifest as the failure of the entire machine. The efficiency and overall machine operation reliability deteriorate, and the overall machine life decreases.

In order to make the actual blade profile of the produced product consistent with the original design as much as possible, it is necessary to combine the elastic properties of the material and the amount of stamping deformation to modify the stamping die multiple times. The entire correction process relies heavily on corresponding process experience, and there will still be certain deviations in the correction results. Because the relationship between the material's elastic properties, stamping deformation amount, and springback amount is complex, it cannot be predicted through calculations, simulations, etc. Therefore, in the actual production process, it is difficult to ensure that the blade performance is completely consistent with the design performance by existing technical means. In addition, the correction process is time-consuming and not completely controllable, making it difficult to guarantee the delivery of finished products.

Contents of the invention:

One purpose of this utility model is to provide a sheet metal centrifugal wind wheel that solves the problem in the prior art that after the blade is stamped, there will be a rebound phenomenon due to the elastic properties of the material, causing the actual blade profile to deviate from the original design. The blade profile causes the blade exit angle to become larger, affecting the efficiency and operational reliability of the entire fan. Therefore, the stamping mold needs to be corrected multiple times. The mold correction process is time-consuming and not completely controllable. It also makes it difficult to guarantee the delivery date of the finished product.

The purpose of the present utility model is achieved through the following technical solutions.

A sheet metal centrifugal wind wheel consists of a wheel disc, a wheel cover, and several blades. The several blades are installed between the wheel disc and the wheel cover. The blades include an inlet side, an outlet side, a blade root, and a blade top. It is characterized by: A corner bending portion is formed on the top corner of the outlet side, and the corner bending portion is bent toward the center of the rotor rotation axis L.

The above-mentioned angular bending part is surrounded by a curve AG, a curve AH and a crease line GH. The above-mentioned curve AG is a section on the exit side, and the length of the curve AG is less than or equal to 1/2 of the length of the exit side.

The above-mentioned method uses several planes perpendicular to the rotor rotation axis L and intersecting the curve AG to intercept the wind rotor to obtain several blade profile lines. The crease line GH and the exit edge intersect with several blade profile lines. Each blade profile line and crease The intersection of the line GH and the exit edge forms a curve VO, and the length of the curve VO gradually increases from point G to vertex A.

A sheet metal centrifugal wind wheel consists of a wheel disc, a wheel cover, and several blades. The several blades are installed between the wheel disc and the wheel cover. The blades include an inlet side, an outlet side, a blade root, and a blade top. It is characterized by: The outlet edge is equidistantly offset to form a crease line NR. The crease line NR and the outlet edge form an equidistant bending part, and the equidistant bending part is bent toward the center of the rotor rotation axis L.

The above-mentioned equidistant offset means that each point on the outlet edge is offset by a considerable distance E along the corresponding blade profile line.

Compared with the existing technology, this utility model has the following effects:

1. Through the sheet metal centrifugal wind wheel of this utility model, the blade structural shape can be stabilized, the rebound effect caused by the release of material stress can be suppressed, and the actual blade profile in the produced product can deviate from the designed blade profile. decrease.

2. Through the sheet metal centrifugal wind wheel of this utility model, the starting point parameters of the blade profile are changed, and the blade outlet angle is reduced. This ensures that the blade outlet airflow angle after rebound conforms to the original design, and reduces the amplitude of the wind wheel beyond the original design range. value to prevent the input and output power of the motor equipped with the wind wheel from increasing beyond the allowable limit range of the motor. This will avoid a series of deteriorating problems such as excessive motor temperature rise, reduced motor output efficiency, and accelerated failure of motor parts.

3. Through the sheet metal centrifugal wind wheel of this utility model, the number of mold modifications is reduced, manufacturing costs and mold costs are saved, mold opening efficiency is greatly increased, uncontrollable factors are reduced, and final blade performance and finished product delivery time are guaranteed.

4. Other advantages of the present utility model are described in detail in the embodiment section.

Picture description:

Figure 1 is a schematic structural diagram of a wind wheel in the prior art;

Figure 2 is a cross-sectional view of the wind wheel taken on a plane perpendicular to the axis of rotation in the prior art;

Figure 3 is a partial enlarged view of part A of Figure 2;

Figure 4 is a schematic diagram of the geometric parameter definition of blade profile in the prior art;

Figure 5 is a comparison diagram of the blade profile in the prior art after rebound and the original design;

Figure 6 is a perspective view of the sheet metal centrifugal wind wheel according to Embodiment 1 of the present invention;

Figure 7 is a perspective view of the sheet metal centrifugal wind wheel from another angle according to Embodiment 1 of the present utility model;

Figure 8 is an exploded view of the sheet metal centrifugal wind wheel according to Embodiment 1 of the present utility model;

Figure 9 is a perspective view of the blades of the sheet metal centrifugal wind wheel according to Embodiment 1 of the present utility model;

Figure 10 is a schematic diagram of the blades divided into four equal parts according to Embodiment 1 of the present invention;

Figure 11 is a schematic diagram of Figure 10 marked on the exit side;

Figure 12 is a schematic diagram of an M-curved surface drawn on the blade of Embodiment 1 of the present utility model;

Figure 13 is a schematic diagram of the blade scanning at point G and intersecting the normal plane according to Embodiment 1 of the present invention;

Figure 14 is a schematic diagram of a line intersection between the M curved surface and the normal plane obtained by scanning the blade at G point according to Embodiment 1 of the present invention;

Figure 15 is a schematic diagram of the M-curved surface rotated around the axis in Embodiment 1 of the present utility model;

Figure 16 is a schematic diagram of the intersection of the blade and the extended M-curved surface in Embodiment 1 of the present invention;

Figure 17 is a schematic diagram of the intersection of the blade profile line and the angular bending portion in Embodiment 1 of the present invention.

Figure 18 is a perspective view of a sheet metal centrifugal wind wheel according to the second embodiment of the present utility model;

Figure 19 is a schematic diagram of the blades of the sheet metal centrifugal wind wheel in Embodiment 2 of the present utility model.

Detailed ways:

The utility model will be described in further detail below through specific embodiments and in conjunction with the accompanying drawings.

Example one:

As shown in Figures 6, 7, 8, and 9, this embodiment provides a sheet metal centrifugal wind wheel, which includes a wheel disk 200, a wheel cover 300, and a plurality of blades 100. The plurality of blades 100 are installed on the wheel disk. 200 and the wheel cover 300, the blade 100 includes an inlet edge 1, an outlet edge 2, a blade root 3 and a blade tip 4. It is characterized in that: a curve AG is formed on the outlet edge 2 from the vertex A to the point G. There is a curve AH from vertex A to point H on the top 4. The line connecting point H and point G on the blade 100 forms a crease line 102. The curve AG, the curve AH and the crease line GH form an angular bend on the blade 100. The bending portion 101 and the angular bending portion 101 are bent toward the center of the rotor rotation axis L.

The length of the above-mentioned curve AG is less than or equal to 1/2 of the length of the exit side 2 .

The process of bending the angular bending portion 101 toward the center of the rotor rotation axis L is described in detail below: 1: As shown in Figure 10, the blade 100 is surrounded by four sides: the inlet side, the outlet side, the blade root and the blade top. From the blade tip to the blade root, 5 blade profile lines can be defined that divide the blade into four equal parts , namely: a blade profile line (located at the blade tip), b blade profile line (located at 1/4 of the blade), c blade profile line (located at 2/4 of the blade), d blade profile line (located at 3/4 of the blade), e blade profile line (located at the blade root). See Figure 11, defined below:

aThe end point of the blade profile is point A on the exit edge;

b The end point of the blade profile is point B on the exit edge;

c The end point of the blade profile is point C on the exit edge.

2: Taking a certain point G on the curve BC as the starting point and vertex A as the end point, draw a scanning path GA and draw a surface M (see point 3 below), as shown in Figure 12. The so-called scanning path starts with G. As the starting point, with the vertex A as the end point, use several planes perpendicular to the rotor rotation axis L to continuously intercept the wind rotor, and the corresponding different blade sections and blade profiles can be obtained;

3: On the normal plane of the scanning path GA (the normal plane is perpendicular to the rotor rotation axis L), the end point of the blade profile line is the coordinate origin, and the tangent direction of the end point of the blade profile line is the positive direction of the X-axis, as shown in Figure 13. Figure 13 is on the normal plane of the starting point G of the scanning path. In Figure 13, point G is the coordinate origin. The characteristics of the above-mentioned curved surface M are: its cross-sectional figure on the normal plane of the scanning path GA is a line segment with any length. ; One endpoint of the line segment is at the origin of the coordinates, and the angle between the line segment and the positive direction of the , in actual implementation, the value of f changes according to the change of the size of the wind wheel, and usually ranges from 3 to 10 degrees.

4: Taking the starting edge of point G of the curved surface M as the axis (that is, taking the line segment GY as the axis of rotation), rotate an angle i degrees toward the center direction of the rotor axis L, as shown in Figure 15, then extend the curved surface M to be in contact with the blade 100 By intersecting, the crease line GH can be obtained, and the point H is on the blade profile line a, as shown in Figure 16. In actual implementation, the value of i changes according to the change of the size of the wind wheel, and usually ranges from 3 to 6 degrees.

5: As shown in Figure 16, fold the AGH area (i.e. the angular bending part 101) of the blade outlet edge close to the blade top to the curved surface M, and completely coincide with the curved surface M, then the blade shape obtained at this time is the original Patented solution.

The essence of this utility model is that the blade exit angle in the bending area is reduced by f degrees; and on the curve GA, the bending lengths of the blade profiles corresponding to different points are different. The reason for this is that the deformation of the blade at the curve GA is large, and the effect of "increasing the working capacity of the blade" is also large. In practice, it is found that the closer to point A, the greater the deformation, so the closer to point A, the longer the bending length of the blade profile. Specifically, as shown in Figure 17, several planes perpendicular to the rotor rotation axis L and intersecting the curve AG are used to intercept the wind rotor to obtain several blade profile lines. The crease line GH and the exit edge 2 intersect with several blade profile lines. , each blade profile line intersects with the crease line GH and the exit edge 2 to form a curve VO. The length of the curve VO gradually increases from point G to vertex A.

1. Through the sheet metal centrifugal wind wheel of this utility model, the blade structural shape can be stabilized, the rebound effect caused by the release of material stress can be suppressed, and the actual blade profile in the produced product can deviate from the designed blade profile. decrease.

2. Through the sheet metal centrifugal wind wheel of this utility model, the starting point parameters of the blade profile are changed, and the blade outlet angle is reduced. This ensures that the blade outlet airflow angle after rebound conforms to the original design, and reduces the amplitude of the wind wheel beyond the original design range. value to prevent the input and output power of the motor equipped with the wind wheel from increasing beyond the allowable limit range of the motor. This will avoid a series of deteriorating problems such as excessive motor temperature rise, reduced motor output efficiency, and accelerated failure of motor parts.

3. Through the sheet metal centrifugal wind wheel of this utility model, the number of mold modifications is reduced, manufacturing costs and mold costs are saved, mold opening efficiency is greatly increased, uncontrollable factors are reduced, and final blade performance and finished product delivery time are guaranteed.

Example 2:

As shown in Figures 18 and 19, a sheet metal centrifugal wind wheel includes a wheel disk 200, a wheel cover 300, and a plurality of blades 100. The plurality of blades 100 are installed between the wheel disk 200 and the wheel cover 300. The blades 100 include an inlet. The edge 1, the exit edge 2, the blade root 3 and the blade top 4 are characterized in that: they are equidistantly offset from the exit edge 2 to form a crease line NR, and the crease line NR and the exit edge 2 form an equidistant bending part 103. The equidistant bending portion 103 is bent toward the center of the rotor rotation axis L.

The above-mentioned equidistant offset means that each point on the outlet edge is offset by a considerable distance along the corresponding blade profile line 5 .

This embodiment can also stabilize the blade structural shape, suppress the rebound effect caused by the release of material stress, and reduce the deviation between the actual blade profile and the designed blade profile in the produced product.

The above embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited thereto. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present utility model shall be considered. Equivalent replacement methods are included in the protection scope of the present utility model.

Claims (5)

1. A sheet metal centrifugal wind wheel, consisting of a wheel disk (200), a wheel cover (300), and several blades (100). The several blades (100) are installed between the wheel disk (200) and the wheel cover (300) , the blade (100) includes an inlet edge (1), an outlet edge (2), a blade root (3) and a blade tip (4), and is characterized in that: an angular bend is formed at the angle of the top of the outlet edge (2). The folding portion (101) and the angular bending portion (101) are bent toward the center of the rotor rotation axis L. 2. A sheet metal centrifugal wind wheel according to claim 1, characterized in that: the angular bending part (101) is surrounded by a curve AG, a curve AH and a crease line GH, and the curve AG is the outlet edge. For a section on (2), the length of the curve AG is less than or equal to 1/2 of the length of the exit side (2). 3. A sheet metal centrifugal wind wheel according to claim 1 or 2, characterized in that: the wind wheel is intercepted by several planes perpendicular to the rotor rotation axis L and intersecting with the curve AG to obtain several blade profile lines. The mark line GH and the outlet edge (2) intersect with several blade profile lines. Each blade profile line intersects the crease line GH and the outlet edge to form a curve VO. The length of the curve VO gradually increases from point G to vertex A. 4. A sheet metal centrifugal wind wheel, including a wheel disk (200), a wheel cover (300), and a number of blades (100). The several blades (100) are installed between the wheel disk (200) and the wheel cover (300) , the blade (100) includes an inlet edge (1), an outlet edge (2), a blade root (3) and a blade tip (4), and is characterized in that: it is equidistant from the outlet edge (2) to form a crease line. NR, the crease line NR and the outlet edge (2) form an equidistant bending part (103), and the equidistant bending part (103) is bent toward the center of the rotor rotation axis L. 5. A sheet metal centrifugal wind wheel according to claim 4, characterized in that: equidistant offset means that each point on the edge of the outlet is offset by a considerable distance E along the corresponding blade profile line.