Blade mechanism for garden blower and garden blower

Abstract

The present invention discloses a blade mechanism for a garden blower and a garden blower, which relates to the field of garden tools. The blade mechanism includes: a hub portion that can rotate around a rotation axis; blades that are arranged on the hub portion. The blades have opposite leeward and windward surfaces, opposite front edges in the gas incoming flow direction, and rear edges opposite the front edges in the gas flow direction, and a top edge at one end far from the hub portion. A first transition portion with a curved surface that converges from the top edge towards the hub portion is provided at the junction of the top edge and the front edge. The cross-section of the first transition portion is circular arc-shaped, and the radius length range of the circular arc-shaped first transition portion is between 0.5 mm and 5 mm. This application can effectively reduce the noise when the air flow detaches to form eddies.

Description

Technical Field

[0001] The present invention relates to the field of gardening tools, and particularly to a blade mechanism for a gardening blower and a gardening blower. Background Art

[0002] A blower is a conventional gardening tool, mainly used for blowing away sundries such as fallen leaves, road dust, accumulated water, and snow. The blower includes a blade mechanism and a motor for driving the rotation of the blade mechanism. Since the blower needs to be convenient for the staff to carry and hold, the volume of the blade mechanism is not too large; and it is also required to generate a wind with a relatively high pressure and wind speed to meet the blowing requirements. Therefore, the blade mechanism with a small volume must operate at a very high rotational speed to generate the required wind force. The blade mechanism will generate various noises due to different reasons at high rotational speeds. Although there are various ways in the prior art to reduce the noises generated by different reasons, the decibel level of the reduced noise is still relatively high and needs to be further reduced to better meet the user's needs. Summary of the Invention

[0003] In order to overcome the above-mentioned defects of the prior art, the technical problem to be solved by the embodiments of the present invention is to provide a blade mechanism for a gardening blower and a gardening blower, which can effectively reduce the noise when the air flow separates from the eddy current.

[0004] The specific technical solution of the embodiments of the present invention is as follows:

[0005] A blade mechanism for a gardening blower, the blade mechanism comprising:

[0006] A hub portion that can rotate around a rotation axis;

[0007] Blades, which are arranged on the hub portion. The blades have opposite leeward and windward surfaces, opposite front edges in the gas incoming flow direction, and rear edges opposite the front edges in the gas flow direction, and a top edge at one end far from the hub portion. The intersection of the top edge and the front edge has a first transition portion with a curved surface that converges from the top edge towards the hub portion. The cross-section of the first transition portion is circular arc-shaped, and the radius length range of the first transition portion being circular arc-shaped is between 0.5 mm and 5 mm.

[0008] Preferably, the radius length range of the first transition portion being circular arc-shaped is between 3 mm and 5 mm.

[0009] Preferably, the intersection point of the extension of the rear edge to the plane where the top edge is located is the starting point, and the intersection point of the extension of the front edge to the plane where the top edge is located is the ending point. The length of the straight line connection from the starting point to the ending point is between 10 mm and 20 mm.

[0010] Preferably, the front edge is substantially planar, and a second transition portion with a curved surface is provided at the junction of the top edge with at least one of the front edge and the leeward surface. The second transition portion includes at least one of the following: a first part of the second transition portion formed at the junction of the top edge and the leeward surface, and a second part of the second transition portion formed at the junction of the top edge and the front edge.

[0011] Preferably, the locus of the junction formed by the top edge, the leeward surface, and the front edge is substantially arc-shaped.

[0012] Preferably, the cross-section of the second transition portion is arc-shaped.

[0013] Preferably, the junction of the top edge and the windward surface is an acute angle or a right angle.

[0014] A garden blower, the garden blower including a blower blade mechanism for a garden blower as described in any one of the above.

[0015] Preferably, the blower further includes a housing having a flow channel, the blower blade mechanism is disposed in the flow channel; a guide vane mechanism disposed in the flow channel, the guide vane mechanism having a stationary guide vane located downstream of the blower blade mechanism in the gas flow direction in the flow channel, and at least a part of the side of the stationary guide vane facing the blower blade mechanism is serrated.

[0016] The technical solution of the present invention has the following remarkable beneficial effects:

[0017] The applicant of the present application has found that in the case of high-speed rotation, the airflow formed by the existing fan blade tips will generate a relatively high-decibel noise when separating from the eddy current, and this noise is also one of the components of the overall noise described above. In order to effectively reduce the noise when the airflow separates from the eddy current, the applicant has studied and found that a first transition portion with a curved surface can be formed at the junction of the top edge and the trailing edge, and this first transition portion can reduce the eddy current formed by the fan blade tips during rotation, thereby reducing the decibel of the noise generated when the airflow separates from the eddy current, and further improving the user experience.

[0018] Referring to the following description and the drawings, specific embodiments of the present invention are disclosed in detail, indicating the ways in which the principles of the present invention can be adopted. It should be understood that the embodiments of the present invention are not limited thereby in scope. Within the spirit and terms of the appended claims, the embodiments of the present invention include many changes, modifications, and equivalents. Features described and / or illustrated for one embodiment can be used in the same or similar manner in one or more other embodiments, combined with the features in other embodiments, or replace the features in other embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure of the present invention in any way. Additionally, the shapes, proportional dimensions, etc. of the components in the drawings are only schematic and are used to assist in understanding the present invention, rather than specifically defining the shapes and proportional dimensions of the components of the present invention. Those skilled in the art can, under the teachings of the present invention, select various possible shapes and proportional dimensions according to specific circumstances to implement the present invention.

[0020] Figure 1 It is a three-dimensional schematic view of the impeller mechanism for a garden blower in the first perspective in an embodiment of the present invention;

[0021] Figure 2 It is a three-dimensional schematic view of the impeller mechanism for a garden blower in the second perspective in an embodiment of the present invention;

[0022] Figure 3 It is a front view of the impeller mechanism for a garden blower in an embodiment of the present invention;

[0023] Figure 4 It is a schematic structural view of the impeller mechanism and the guide vane mechanism installed together in an embodiment of the present invention;

[0024] Figure 5 It is a schematic structural view of the guide vane mechanism in an embodiment of the present invention;

[0025] Figure 6 It is a noise comparison diagram of an impeller mechanism with 17 fan blades and an impeller mechanism with 12 fan blades;

[0026] Figure 7 It is a comparison diagram of noise and blowing force when the first transition part of the impeller mechanism is an arc with different radii;

[0027] Figure 8 It is a noise reduction comparison diagram of a static guide vane with serrations and a static guide vane without serrations.

[0028] Reference numerals of the above accompanying drawings:

[0029] 1. Hub part; 2. Fan blade; 21. Windward surface; 22. Leeward surface; 23. Front edge; 24. Rear edge; 25. Top edge; 26. First transition part; 27. Second transition part; 271. First part of the second transition part; 272. Second part of the second transition part; 100. Impeller mechanism; 200. Guide vane mechanism; 201. Static guide vane. Detailed implementation manners

[0030] Combined with the accompanying drawings and the description of the specific embodiments of the present invention, the details of the present invention can be more clearly understood. However, the specific embodiments of the present invention described herein are only for the purpose of explaining the present invention and cannot be construed in any way as a limitation of the present invention. Under the teaching of the present invention, those skilled in the art can conceive any possible variations based on the present invention, and these should all be regarded as belonging to the scope of the present invention. It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "mounted", "connected", and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the communication inside two elements. It can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only embodiments.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0032] In order to effectively reduce the noise when the air flow breaks away from the eddy current, a blade mechanism 100 for a garden blower is proposed in this application. Figure 1 It is a three-dimensional schematic diagram of the blade mechanism for a garden blower in the first perspective in the embodiment of the present invention. Figure 2 It is a three-dimensional schematic diagram of the blade mechanism for a garden blower in the second perspective in the embodiment of the present invention. As Figure 1 and Figure 2 shown, the blade mechanism 100 for a garden blower may include: a hub portion 1 that can rotate around a rotation axis; a blade 2 disposed on the hub portion 1. The blade 2 has an opposite leeward surface 22 and windward surface 21, opposite front edges 23 and rear edges 24, and a top edge 25 located at one end away from the hub portion 1. The rear edge 24 is located at one end in the gas flow direction. At the junction of the top edge 25 and the rear edge 24, there is a first transition portion 26 with a curved surface that converges from the top edge 25 towards the hub portion 1. The cross-section of the first transition portion 26 is in an arc shape, and the radius length range of the first transition portion 26 in the arc shape is between 0.5 mm and 5 mm.

[0033] When the number of fan blades 2 is relatively large and the rotational speed of the wind blade mechanism is higher, the air volume output by the fan mechanism can be effectively increased. However, this will cause a significant increase in the decibels of the noise generated by the rotation of the tips of the fan blades 2. Especially when the rotational speed of the fan mechanism reaches between 18,000 RPM and 80,000 RPM, the increase in the decibels of the noise generated by the tips of the fan blades 2 is particularly obvious. This noise level is relatively high and most users cannot tolerate it. The applicant of this application found that in the case of high-speed rotation, the airflow formed by the tips of the existing fan blades 2 will generate a relatively high-decibel noise when separating from the eddy current. This noise is also one of the components of the above-mentioned overall noise. In order to effectively reduce the noise when the airflow separates from the eddy current, the applicant's research found that a first transition portion 26 with a curved surface that slopes from the top edge 25 towards the hub portion 1 can be formed at the junction of the top edge 25 and the trailing edge 24. The cross-section of the first transition portion 26 is arc-shaped. When the radius length range of the arc-shaped first transition portion 26 is between 0.5 mm and 5 mm, the first transition portion 26 can reduce the eddy current formed by the tips of the fan blades 2 during rotation, thereby reducing the decibels of the noise generated when the airflow separates from the eddy current, and further improving the user experience.

[0034] As Figure 1 and Figure 2 shown, the hub portion 1 of the wind blade mechanism 100 for a garden blower has a rotating shaft, and the entire wind blade mechanism 100 rotates around this rotating shaft. The outer sidewall of the hub portion 1 is used for arranging the fan blades 2 in the circumferential direction. The inside of the hub portion 1 can be used for driving connection with a motor so that the motor drives the entire wind blade mechanism 100 to rotate. The end of the hub portion 1 in the direction of the gas inflow when the wind blade mechanism 100 rotates has a guiding surface for guiding the airflow towards the direction of the fan blades 2. This guiding surface can be a partial or complete elliptic paraboloid, elliptic cone, cone, etc., and no specific limitation is made here.

[0035] As Figure 1 and Figure 2As shown, the blades 2 of the fan blade mechanism 100 are arranged on the hub portion 1, and the two can be integrally formed. The blades 2 are distributed in a circle around the rotation axis of the hub portion 1. The blades 2 can be divergent, and the connection between the blades 2 and the hub portion 1 generally forms a straight line with an angle with the rotation axis of the hub portion 1, and the angle is less than or equal to 45 degrees. Generally speaking, the angle is small, so that a larger number of blades 2 can be arranged on the hub portion 1. In order to make the airflow formed when the blades 2 rotate more efficient, the connection between the blades 2 and the hub portion 1 generally forms a straight line with a certain angle with the rotation axis of the hub portion 1, and the angle cannot be as small as possible. Therefore, in order to be able to further arrange more blades 2 on the hub portion 1, the length of the blade 2 in the extension direction close to the hub portion 1 is smaller than the length of the blade 2 in the extension direction away from the hub portion 1, that is, the length of the connection between the blade 2 and the hub portion 1 is smaller than the length of the blade 2 in the extension direction away from the hub portion 1. Since the diameter of the connection between the hub portion 1 and the blade 2 is small, the circumference is also small. When the length of the blade 2 in the extension direction close to the hub portion 1 is smaller than the length of the blade 2 in the extension direction away from the hub portion 1, more blades 2 can be arranged in the circumference of the hub portion 1. Moreover, Figure 3 FIG. 2 is a front view of a blade mechanism for a garden hair dryer according to an embodiment of the present invention. Figure 3 As shown, the above method can make the projections of the fan blades 2 on the plane perpendicular to the rotation axis not overlap. Compared with the overlapping design, the design in which the projections of the fan blades 2 on the plane perpendicular to the rotation axis do not overlap can make the wind force generated by the fan blades 2 during the rotation process stronger. In summary, by combining the above two methods, the fan blade mechanism 100 in the present application can greatly enhance the wind force and efficiency of the wind formed during rotation. When the number of fan blades 2 increases, the frequency formed by the fan blades 2 when the fan blade mechanism rotates is also higher. After reaching 12700Hz, the human ear basically will not perceive the sound above this frequency. Therefore, this also reduces the harmonic sharp sound of the fan blade mechanism in disguise.

[0036] In a specific embodiment, when the diameter of the hub portion 1 is 27 mm or 29 mm, or less than or equal to 29 mm, the more blades 2 there are, the more powerful the airflow is when the blade mechanism rotates. However, when processing the blade mechanism, in order to ensure the overall strength and connection strength of the blade mechanism, the entire blade mechanism is integrally formed. Therefore, there is a minimum gap between the blades 2 that can be achieved by the mold. At present, the minimum gap between the blades 2 allowed by the mold is 2 mm. Therefore, on this basis, after optimization by this application, the number of blades 2 can reach 17. Figure 6 This is a noise comparison diagram of a fan blade mechanism with 17 fan blades and a fan blade mechanism with 12 fan blades.Figure 6 As shown, the X-axis in the figure represents the rotational speed of the blade mechanism, and the Y-axis represents the decibels of noise. It can be seen from the figure that at different rotational speeds, the decibels of noise generated by the blade mechanism with 17 blades 2 are basically less than those generated by the blade mechanism with 12 blades 2. For the weighted composite sound pressure levels obtained in the above two cases, the overall noise reduction of the blade mechanism with 17 blades 2 is about 1.5 decibels compared to the blade mechanism with 12 blades 2. For the tip sound octave, the blade mechanism with 17 blades 2 reduces the noise by about 5 decibels compared to the blade mechanism with 12 blades 2.

[0037] In a feasible implementation, as Figure 3 shown, the blades 2 can be arranged at non-uniform intervals, and the angle between adjacent blades 2 can be between 19 degrees and 23 degrees. By arranging the blades 2 in a non-uniform interval distribution, both the fundamental frequency and the high-order harmonics of the noise generated by the rotation of the blades 2 can be reduced compared to the blades 2 with equal intervals. In particular, most of the high-order harmonics disappear. In this way, the sharp sound decibels at the tips of the blades 2 can be reduced to a certain extent at high rotational speeds, thereby improving the user experience.

[0038] As Figure 1 and Figure 2 shown, the contour of the blade 2 is generally rectangular, and of course, it has a certain curved surface. The blade 2 has a leeward surface 22 and a windward surface 21 that are opposite to each other, a front edge 23 and a rear edge 24 that are opposite to each other, and a top edge 25 located at one end away from the hub portion 1. Most of the top edge 25 is generally planar. Among them, the front edge 23 and the rear edge 24 are on both sides between the leeward surface 22 and the windward surface 21. The rear edge 24 can be a line formed by the intersection of the edges of the leeward surface 22 and the windward surface 21, or can be a surface formed between the leeward surface 22 and the windward surface 21. The front edge 23 is generally located at one end in the gas inflow direction, and the rear edge 24 is generally located at one end in the gas flow direction. At the junction of the top edge 25 and the second side 24, there is a first transition portion 26 with a curved surface that converges from the top edge 25 towards the hub portion 1. The cross-section of the first transition portion 26 is circular arc-shaped, and the radius length range of the first transition portion 26 being circular arc-shaped is between 0.5 mm and 5 mm. This curved first transition portion 26 can reduce the eddy current formed at the tip of the blade 2 during rotation, thereby reducing the decibels of the noise generated when the airflow breaks away from the eddy current.

[0039] When the cross-section of the first transition portion 26 on the plane roughly extending along the fan blade is in the shape of an arc, it can be more conducive to directing the airflow at the tip of the fan blade 2 to the duct area between the fan blade 2 and the fan blade 2 when the fan blade mechanism rotates, thereby better reducing the vortex formed at the tip of the fan blade 2 when rotating, and then reducing the pressure of the wall layer airflow at the tip of the fan blade 2 impacting the fan blade 2, and finally achieving the purpose of further reducing the aerodynamic noise, that is, reducing the blade frequency sharp sound. Preferably, the rear edge 24 extends to the intersection of the plane where the top edge 25 is located as the starting point, and the front edge 23 extends to the intersection of the plane where the top edge 25 is located as the end point, and the length of the straight line A from the starting point to the end point is between 10mm and 20mm. When the fan blade is within the above-mentioned size range, the effect of the fan blade mechanism on reducing aerodynamic noise is more obvious. Figure 7 The noise and blowing force comparison diagram when the first transition part of the fan blade mechanism is an arc with different radii is shown in FIG. Figure 7 As shown, it is found through experiments that the larger the radius of the first transition portion in the shape of an arc, the greater the reduction in the decibel of the noise generated when the fan mechanism rotates, and at the same time, the loss of blowing force is also weakened to a certain extent, but the weakening is not large. Therefore, the appropriate size selection of the radius of the first transition portion 26 in the shape of an arc can help reduce noise while maintaining the blowing force to meet the requirements. It can be seen from the above experimental data that the radius length range of the first transition portion 26 in the shape of an arc can be preferably selected between 3mm and 5mm, so that it can not only maintain the blowing force to meet the requirements, but also help reduce noise.

[0040] like Figure 1 and Figure 2 As shown, the intersection of the top edge 25 and the windward surface 21 is an acute angle or a right angle. The intersection of the top edge 25 and the windward surface 21 is still a ridged edge formed by the intersection of the surfaces. The purpose of this structure is that when the fan mechanism rotates, the windward surface 21 can drive the gas to the maximum extent to generate an airflow with high blowing force. Although the intersection of the top edge 25 and the windward surface 21 can also reduce noise to a certain extent if it is a curved surface, the applicant has found that this will weaken the blowing force too much. Therefore, in a preferred embodiment, the intersection of the top edge 25 and the windward surface 21 in this application is an acute angle or a right angle.

[0041] like Figure 1 and Figure 2As shown, the front edge 23 can be generally planar, and a second transition portion 27 with a curved surface is provided at the junction of the top edge 25 and at least one of the front edge 23 and the leeward surface 22. The second transition portion 27 can at least include one of the following: a first part 271 of the second transition portion formed at the junction of the top edge 25 and the leeward surface 22, and a second part 272 of the second transition portion formed at the junction of the top edge 25 and the front edge 23. The second transition portion 27 is arc-shaped in a cross-section along a plane substantially perpendicular to the top edge 25 and the windward surface 21.

[0042] In a feasible implementation manner, when the second transition portion 27 includes the first part 271 of the second transition portion formed at the junction of the top edge 25 and the leeward surface 22 and the second part 272 of the second transition portion formed at the junction of the top edge 25 and the front edge 23, the locus of the junction jointly formed by the top edge 25, the leeward surface 22, and the front edge 23 can be generally arc-shaped. This design can also reduce the noise generated at the junction of the first part 271 and the second part 272 of the second transition portion at the tip of the fan blade 2 during rotation to a certain extent, thereby achieving the purpose of reducing the noise decibel.

[0043] In the present application, a garden blower is further proposed, and the blower includes the wind blade mechanism for the garden blower as described in any one of the above. Figure 4 It is a schematic structural diagram of the wind blade mechanism and the guide blade mechanism installed together in the embodiment of the present invention. Figure 5 It is a schematic structural diagram of the guide blade mechanism in the embodiment of the present invention, as Figure 4 and Figure 5 As shown, the blower can include: a housing having a flow channel, and the wind blade mechanism 100 is provided in the flow channel; a guide blade mechanism 200 provided in the flow channel. The guide blade mechanism 200 has stationary guide vanes 201 located downstream of the wind blade mechanism 100 in the gas flow direction in the flow channel. The stationary guide vanes 201 can be multiple pieces, and they are also circumferentially distributed around the rotation axis of the wind blade mechanism 100. The stationary guide vanes 201 are used to guide the airflow generated by the rotation of the wind blade mechanism 100 and make the airflow more uniform everywhere.

[0044] One side of the stationary guide vane 201 in the present application facing the wind blade mechanism 100 can be at least partially serrated. When the airflow generated by the rotation of the wind blade mechanism 100 flows towards the stationary guide vane 201, since the serrated side of the stationary guide vane 201 faces the wind blade mechanism 100, this serrated structure can effectively disrupt the locally pressure-concentrated areas in the airflow, so that the overall internal pressure of the airflow is more uniform. At the same time, after the overall internal pressure of the airflow becomes more uniform, compared with before, the noise generated by the airflow is further reduced. Figure 8It is a noise reduction comparison diagram of a serrated stationary guide vane and a non-serrated stationary guide vane. As Figure 8 shown, among them, the curve with a lighter color represents the noise emitted by the non-serrated stationary guide vane, and the curve with a darker color represents the noise emitted by the serrated stationary guide vane in this application. The X-axis represents the hertz of the noise, and the Y-axis represents the decibel of the noise at a certain hertz. In the vane mechanism 100 in the above two cases, the fan blade 2 has the same curved transition part. It can be seen from the figure that compared with the non-serrated stationary guide vane, the sharp noise of the serrated stationary guide vane is reduced by about 8 decibels, and the overall composite sound pressure level is reduced by about 1.5 decibels. Thus, it can be seen that the serrated stationary guide vane plays a good role in noise reduction.

[0045] All articles and references disclosed, including patent applications and publications, are incorporated herein by reference for various purposes. The term "consisting essentially of" describing a combination shall include the identified elements, components, parts or steps and other elements, components, parts or steps that do not substantially affect the basic novel features of the combination. The use of the terms "comprising" or "including" to describe the combinations of elements, components, parts or steps herein also contemplates embodiments consisting essentially of these elements, components, parts or steps. By using the term "may" herein, it is intended to indicate that any attribute described as "may" included is optional. Multiple elements, components, parts or steps can be provided by a single integrated element, component, part or step. Alternatively, a single integrated element, component, part or step can be divided into separate multiple elements, components, parts or steps. The disclosure of "a" or "an" used to describe an element, component, part or step does not mean to exclude other elements, components, parts or steps.

[0046] Each embodiment in this specification is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. The above embodiments are only for explaining the technical concept and characteristics of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A garden hair dryer, characterized in that, The garden blower includes: A housing having a flow channel; A guide vane mechanism disposed in the flow channel of the housing; An impeller mechanism disposed in the flow channel of the housing; The impeller mechanism includes: A hub portion that can rotate about a rotation axis; Blades disposed on the hub portion. The blades have opposite leeward and windward surfaces, opposite leading edges in the gas inflow direction, and opposite trailing edges in the gas flow direction relative to the leading edges, and a top edge at one end away from the hub portion. At the junction of the top edge and the trailing edge, there is a first transition portion with a curved surface that converges from the top edge towards the hub portion. The cross-section of the first transition portion is circular arc-shaped, and the radius length range of the first transition portion in the circular arc shape is between 0.5 mm and 5 mm; the leading edge is generally planar, and at the junction of the top edge and at least one of the leading edge and the leeward surface, there is a second transition portion with a curved surface. The second transition portion includes at least one of the following: a first part of the second transition portion formed at the junction of the top edge and the leeward surface, a second part of the second transition portion formed at the junction of the top edge and the leading edge; the junction of the top edge and the windward surface is an acute angle or a right angle.

2. The garden hair dryer according to claim 1, characterized in that, The radius length range of the first transition portion in the circular arc shape is between 3 mm and 5 mm.

3. The garden blower according to claim 1, characterized in that, Taking the intersection point of the extension of the trailing edge to the plane where the top edge is located as the starting point, and the intersection point of the extension of the leading edge to the plane where the top edge is located as the ending point, the length of the straight line connection from the starting point to the ending point is between 10 mm and 20 mm.

4. The garden blower according to claim 1, characterized in that, The locus of the junction formed by the top edge, the leeward surface, and the leading edge is generally circular arc-shaped.

5. The garden blower according to claim 1, characterized in that, The cross-section of the second transition portion is circular arc-shaped.

6. The garden hair dryer according to claim 1, wherein The guide vane mechanism has a stationary guide vane located downstream of the impeller mechanism in the gas flow direction in the flow channel, and at least a part of the side of the stationary guide vane facing the impeller mechanism is serrated.

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