Blower

Abstract

To provide a technique capable of suppressing generation of noise when air flows through a nozzle tube.SOLUTION: A blower includes a fan, a casing having a discharge port and housing the fan, and a nozzle 80 attachable to the discharge port. The nozzle includes a nozzle tube 82 in the inside of which air flows, and plate members 92, 94 disposed inside the nozzle tube. Rear end surfaces of the plate members are inclined to a flow direction in which air flows inside the nozzle tube.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a blower. [Background technology]

[0002] Patent Document 1 discloses a blower. The blower includes a fan, a casing, and a nozzle. The casing has an outlet and houses the fan. The nozzle can be attached to the outlet. The nozzle includes a nozzle tube through which air flows. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-148951 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above blower, an access prevention member having a plate member may be arranged inside the nozzle tube to prevent an operator from reaching the casing when inserting his / her hand through the tip opening of the nozzle tube. However, when a plate member is arranged inside the nozzle tube, noise may be generated when air flows through the nozzle tube. This specification discloses a technology that can suppress the generation of noise when air flows through the nozzle tube. [Means for solving the problem]

[0005] This specification discloses a blower. The blower includes a fan, a casing having an outlet and accommodating the fan, and a nozzle attachable to the outlet. The nozzle includes a nozzle tube through which air flows, and a plate member disposed inside the nozzle tube. A rear end surface of the plate member is inclined with respect to the flow direction of the air flowing inside the nozzle tube.

[0006] The air that flows into the nozzle pipe flows around the plate member. This generates a turbulent flow. If the rear end face of the plate member is not inclined with respect to a plane perpendicular to the flow direction, the turbulent flow may generate noise in a narrow specific frequency range. In the above configuration, since the rear end face of the plate member is inclined with respect to the flow direction, the position and distribution where the turbulent flow occurs can be changed with respect to the flow direction. This makes it possible to suppress the generation of noise.

[0007] This specification also discloses a blower. The blower includes a fan, a casing having an outlet and accommodating the fan, and a nozzle attachable to the outlet. The nozzle includes a nozzle tube through which air flows, and a plate member disposed inside the nozzle tube. The plate member has a slit penetrating the plate member in the flow direction of air flowing inside the nozzle tube.

[0008] If the plate member does not have a slit, turbulence may occur, causing noise in a narrow, specific frequency range. In the above configuration, since the plate member has a slit, air flows through the slit in addition to flowing around the plate member. Compared to when the plate member does not have a slit, the position and distribution where turbulence occurs can be changed. This makes it possible to suppress the generation of noise. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view of the blower 2 of the first embodiment. [Diagram 2] 2 is a vertical cross-sectional view of the vicinity of a motor 70 of the blower 2 of the first embodiment. FIG. [Diagram 3] FIG. 2 is a cross-sectional view of the blower 2 of the first embodiment. [Figure 4] FIG. 2 is a cross-sectional view of the nozzle 80 of the first embodiment. [Diagram 5] FIG. 2 is a rear view of the nozzle 80 of the first embodiment. [Figure 6]2 is a cross-sectional perspective view of the nozzle 80 of the first embodiment, showing the vicinity of a rear end surface 84a of an access prevention member 84. FIG. [Figure 7] FIG. 11 is a perspective view of a blower 102 according to a second embodiment. [Figure 8] FIG. 11 is a cross-sectional view of a blower 102 according to a second embodiment. [Figure 9] FIG. 11 is a cross-sectional view of a nozzle 80 of a third embodiment. [Figure 10] FIG. 11 is a cross-sectional view of a nozzle 80 of a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Representative, non-limiting embodiments of the present invention are described in detail below with reference to the drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Additionally, the additional features and inventions disclosed may be used separately or in conjunction with other features and inventions to provide further improved blowers.

[0011] In addition, the combinations of features and steps disclosed in the following detailed description are not essential for implementing the present invention in the broadest sense, but are specifically described only to illustrate representative embodiments of the present invention. Furthermore, the various features of the following representative embodiments and the various features described in the claims do not have to be combined in the exact manner of the embodiments described herein or in the order listed in order to provide additional and useful embodiments of the present invention.

[0012] All features described in the specification and / or claims are intended to be disclosed individually and independently of one another as limitations to the specific features described in the original disclosure and claims, apart from the configuration of features described in the examples and / or claims. Furthermore, all numerical ranges and group or aggregate descriptions are intended to disclose intermediate configurations thereof as limitations to the specific features described in the original disclosure and claims.

[0013] In one or more embodiments, the rear end surface of the plate member may be located upstream in the flow direction as it moves radially inward of the nozzle pipe.

[0014] In the above configuration, when the rear end surface of the plate member is located on the upstream side in the flow direction toward the inside in the radial direction of the nozzle pipe, the position and distribution of turbulent flow in the flow direction can be changed in the radial direction of the nozzle pipe, thereby making it possible to further suppress the generation of noise.

[0015] In one or more embodiments, the rear end surface of the plate member may be located downstream in the flow direction as it moves radially inward of the nozzle pipe.

[0016] In the above configuration, when the rear end surface of the plate member is located downstream in the flow direction toward the inside in the radial direction of the nozzle pipe, the position and distribution of turbulent flow in the flow direction can be changed in the radial direction of the nozzle pipe, thereby making it possible to further suppress the generation of noise.

[0017] In one or more embodiments, the rear end surface of the plate member may be inclined at an angle of 30 degrees or more and 85 degrees or less with respect to the flow direction.

[0018] If the rear end surface of the plate member is inclined at an angle of less than 30 degrees with respect to the flow direction, the strength of the plate member is insufficient. Also, if the rear end surface of the plate member is inclined at an angle of more than 85 degrees with respect to the flow direction, the generation of noise cannot be sufficiently suppressed. With the above configuration, the generation of noise can be suppressed while ensuring the strength of the access prevention member.

[0019] In one or more embodiments, the plate member may have a notch.

[0020] In the above-described configuration, the position and distribution of turbulent flow can be changed by the simple configuration of providing notches in the plate member, thereby making it possible to suppress the generation of noise.

[0021] In one or more embodiments, the plate member may have dimples.

[0022] In the above-described configuration, the simple structure of providing dimples on the plate member makes it possible to change the location and distribution of turbulent flow and suppress the generation of noise.

[0023] In one or more embodiments, the plate member may be formed with a portion having a surface roughness of 0.1 or more.

[0024] If the plate member does not have a portion with a surface roughness of 0.1 or more, the generation of noise cannot be sufficiently suppressed. With the above configuration, the position and distribution of turbulent flow changes, thereby making it possible to suppress the generation of noise.

[0025] In one or more embodiments, the width of the plate in the flow direction may be 10% or more of the inner diameter of the nozzle tube.

[0026] If the width of the plate member is smaller than 10% of the inner diameter of the nozzle pipe, the strength of the plate member is insufficient. With the above configuration, the strength of the plate member can be ensured.

[0027] In one or more embodiments, when the nozzle is viewed in the flow direction, the thickness of the plate member may be 1% or more and 8% or less of the inner diameter of the nozzle pipe.

[0028] If the thickness of the plate member is less than 1% of the inner diameter of the nozzle pipe, the strength of the plate member is insufficient. If the thickness of the plate member is more than 8% of the inner diameter of the nozzle pipe, the flow path resistance in the nozzle pipe becomes large. With the above configuration, the strength of the plate member is ensured and the flow path resistance of the nozzle pipe can be prevented from becoming too large.

[0029] (First embodiment) A blower 2 according to a first embodiment will be described with reference to Figs. 1 to 6. The blower 2 is a handheld blower. The blower 2 can blow away fallen leaves and the like on the ground. In the following, the direction in which a shaft 70a of a motor 70 (see Fig. 2) described later extends is referred to as the left-right direction, the direction perpendicular to the left-right direction is referred to as the front-rear direction, and the direction perpendicular to the left-right direction and the front-rear direction is referred to as the up-down direction.

[0030] 1, the blower 2 includes a casing 4, a leg member 16, a plurality of (two in this embodiment) battery packs B, a trigger 24, and a main power switch 26. As shown in FIG 2, the casing 4 includes a left casing 4a that defines the outer shape of the left half of the casing 4, and a right casing 4b that defines the outer shape of the right half of the casing 4.

[0031] 1, the casing 4 includes a main casing 6, a side casing 8, a front connection part 10, a rear connection part 12, and a grip 14. The side casing 8 is fixed to the left side surface of the main casing 6 with screws.

[0032] The front connection part 10 extends upward from the front upper part of the main casing 6. The rear connection part 12 extends upward from the rear upper part of the main casing 6. The grip 14 extends from the rear upper part of the front connection part 10 to the front upper part of the rear connection part 12. The grip 14 is disposed on the upper side of the main casing 6. The grip 14 is held by an operator. The leg member 16 is fixed to the lower part of the main casing 6. When the blower 2 is placed on the ground, only the leg member 16 comes into contact with the ground.

[0033] Two battery packs B are removably attached to the front surface of the main casing 6. The two battery packs B are electrically connected in series. In a modified example, the two battery packs B may be electrically connected in parallel. The battery packs B include, for example, a lithium ion battery.

[0034] A trigger 24 is attached to the grip 14. The trigger 24 is pressed by the fingers of the hand of an operator holding the grip 14.

[0035] The main power switch 26 is disposed on the middle surface 28. The middle surface 28 is disposed near the left side surface of the casing 4 and faces upward. The main power switch 26 is operated by the operator with the hand opposite to the hand holding the grip 14. The main power switch 26 is a switch that switches the blower 2 between an on state and an off state. When the blower 2 is in the off state, rotation of the motor 70, which will be described later, is prohibited. In this case, even if the trigger 24 is pressed, the motor 70 does not rotate. On the other hand, when the blower 2 is in the on state, rotation of the motor 70 is permitted. In this case, when the trigger 24 is pressed, the motor 70 rotates.

[0036] As shown in FIG. 2, the casing 4 includes a housing 32 and a volute 34. The housing 32 has a fan housing chamber 40 therein. The volute 34 is formed integrally with the housing 32. The volute 34 is disposed radially outward of the housing 32 with respect to the radial direction of the central axis AX extending in the left-right direction. As shown in FIG. 3, the volute 34 has an air passage 42 therein through which air flows. The air passage 42 communicates with the fan housing chamber 40. The air passage 42 extends in a spiral shape around the central axis AX. The air passage 42 communicates with the outside of the blower 2 via a discharge port 64 of the volute 34.

[0037] As shown in FIG. 2, the casing 4 has a motor accommodating chamber 60 and an air intake port 62. The motor accommodating chamber 60 is defined by the main casing 6 and the side casing 8. The motor accommodating chamber 60 is disposed on the left side of the fan accommodating chamber 40. The air intake port 62 is disposed on the right side surface of the housing 32 in the right casing 4b. The air intake port 62 penetrates the right side surface of the housing 32. The air intake port 62 communicates with the fan accommodating chamber 40. The air intake port 62 is covered by a cover 68. A number of small openings are formed in the cover 68.

[0038] The blower 2 further includes a motor 70, a control board 72, a fan 74, and blades 76. The motor 70 and the control board 72 are disposed in the motor housing chamber 60. The motor 70 is a prime mover, for example, a brushless motor. In a modified example, the motor 70 may be an engine or a brushed motor. The motor 70 rotates by power from two battery packs B. The control board 72 controls the rotation of the motor 70 in response to the operation of the trigger 24.

[0039] The fan 74 and the blades 76 are disposed in the fan housing chamber 40. The fan 74 is fitted to the vicinity of the right end of the shaft 70a of the motor 70. The fan 74 is a centrifugal fan. The blades 76 are fitted to the shaft 70a to the right of the fan 74. When the motor 70 rotates, the fan 74 and the blades 76 rotate around the central axis AX. As a result, air passes through the intake port 62 and flows into the fan housing chamber 40. Dust (e.g., fallen leaves and pebbles) that enters the fan housing chamber 40 together with the air is crushed by the blades 76. The air that has flowed into the fan housing chamber 40 is sent out by the fan 74 radially outward from the central axis AX.

[0040] As shown in FIG. 1, a nozzle 80 is removably attached to the discharge port 64 of the volute 34. As shown in FIG. 4, the nozzle 80 includes a nozzle tube 82 and an access prevention member 84. The nozzle tube 82 has a substantially cylindrical shape extending in the longitudinal direction. Air that has passed through the discharge port 64 flows inside the nozzle tube 82. The access prevention member 84 is formed integrally with the nozzle tube 82. The access prevention member 84 is disposed inside the nozzle tube 82. When an operator inserts his / her hand from the tip opening of the nozzle tube 82, the access prevention member 84 prevents the hand from reaching the casing 4 (see FIG. 3). The access prevention member 84 is disposed near the center in the longitudinal direction of the nozzle tube 82. In addition, the length L1 of the access prevention member 84 is the same as the inner diameter D1 of the nozzle tube 82 in a direction perpendicular to the flow direction of air inside the nozzle tube 82 (i.e., the direction from the rear end to the front end of the access prevention member 84). The length L1 of the access prevention member 84 and the inner diameter D1 of the nozzle tube 82 are 82 mm.

[0041] The access prevention member 84 includes four central plate members 92 and four outer plate members 94. The four central plate members 92 and the four outer plate members 94 are integrally formed. The side surfaces of the four central plate members 92 and the side surfaces of the four outer plate members 94 are arranged along the flow direction. The four central plate members 92 are arranged radially inward of the nozzle pipe 82 relative to the four outer plate members 94. As shown in FIG. 5, when the access prevention member 84 is viewed in the flow direction, the four central plate members 92 are connected at an angle of 90 degrees to each other. The shape of the four central plate members 92 connected to each other is substantially rectangular. Each of the four outer plate members 94 extends from a corner of the rectangle formed by connecting the four central plate members 92 to the inner surface of the nozzle pipe 82. The four outer plate members 94 are arranged at intervals of 90 degrees from each other in the circumferential direction of the inner peripheral surface of the nozzle pipe 82. The thickness T1 of each of the central plate member 92 and the outer plate member 94 is the same. The thickness T1 of each of the central plate member 92 and the outer plate member 94 is 1 mm or more and 5 mm or less, and in this embodiment, the thickness T1 of each of the central plate member 92 and the outer plate member 94 is 2 mm. Furthermore, the thickness T1 of each of the central plate member 92 and the outer plate member 94 is 1% or more and 8% or less of the inner diameter D1 of the nozzle pipe 82, and in this embodiment, the thickness T1 of each of the central plate member 92 and the outer plate member 94 is 2.5% of the inner diameter D1 of the nozzle pipe 82.

[0042] As shown in Fig. 4, the widths W1 of the central plate member 92 and the outer plate member 94 in the flow direction are the same. The widths W1 of the central plate member 92 and the outer plate member 94 are 10 mm or more, and in this embodiment, the widths W1 of the central plate member 92 and the outer plate member 94 are 15 mm. The widths W1 of the central plate member 92 and the outer plate member 94 are 10% or more of the inner diameter D1 of the nozzle pipe 82, and in this embodiment, the widths W1 of the central plate member 92 and the outer plate member 94 are 18% of the inner diameter D1 of the nozzle pipe 82. In a modified example, the widths W1 of the central plate member 92 and the outer plate member 94 may be 20% or more of the inner diameter D1 of the nozzle pipe 82.

[0043] The rear end surface 84a of the access prevention member 84 is composed of a rear end surface 92a of the central plate member 92 and a rear end surface 94a of the outer plate member 94. The rear end surface 92a of the central plate member 92 and the rear end surface 94a of the outer plate member 94 are inclined with respect to the flow direction. Inclined means that they form an angle greater than 0 degrees with the flow direction and also form an angle greater than 0 degrees with respect to a plane perpendicular to the flow direction. The rear end surface 92a of the central plate member 92 and the rear end surface 94a of the outer plate member 94 are not parallel to the plane perpendicular to the flow direction, and are also inclined with respect to the plane perpendicular to the flow direction.

[0044] As shown in FIG. 6, in terms of the flow direction, the central portion 92b of the rear end surface 92a of the central plate member 92 is located on the most upstream side, and both ends 92c of the rear end surface 92a of the central plate member 92 are located on the most downstream side. The central portion 92b represents the center in the longitudinal direction of the rear end surface 92a of the central plate member 92 when the access prevention member 84 is viewed in the flow direction, and both ends 92c represent both ends in the longitudinal direction of the rear end surface 92a of the central plate member 92 when the access prevention member 84 is viewed in the flow direction. The central portion 92b of the rear end surface 92a of the central plate member 92 is located on the innermost radial side of the inner surface of the nozzle pipe 82, and both ends 92c of the rear end surface 92a of the central plate member 92 are located on the outermost radial side of the inner surface of the nozzle pipe 82. The rear end surface 92a of the central plate member 92 is located on the upstream side in the flow direction (i.e., on the discharge port 64 side) as it moves toward the inner side in the radial direction of the nozzle pipe 82. The rear end surface 92a of the central plate member 92 forms the noise suppression mechanism 88. The rear end surface 92a of the central plate member 92 is inclined at an angle of 30 degrees or more and 85 degrees or less with respect to the flow direction (i.e., an angle of 5 degrees or more and 60 degrees or less with respect to a plane perpendicular to the flow direction), and in this embodiment, the rear end surface 92a of the central plate member 92 is inclined at an angle of 60 degrees with respect to the flow direction (i.e., an angle of 30 degrees with respect to a plane perpendicular to the flow direction). It is preferable that the rear end surface 92a of the central plate member 92 is inclined at an angle of 40 degrees or more and 80 degrees or less with respect to the flow direction (i.e., an angle of 10 degrees or more and 50 degrees or less with respect to a plane perpendicular to the flow direction).

[0045] As shown in FIG. 4, the rear end surface 94a of the outer plate member 94 is located on the upstream side in the flow direction as it moves toward the inside in the radial direction of the nozzle pipe 82. The rear end surface 94a of the outer plate member 94 forms a noise suppression mechanism 88. The rear end surface 94a of the outer plate member 94 is inclined at an angle of 30 degrees or more and 85 degrees or less with respect to the flow direction (i.e., an angle of 5 degrees or more and 60 degrees or less with respect to a plane perpendicular to the flow direction), and in this embodiment, the rear end surface 94a of the outer plate member 94 is inclined at an angle of 60 degrees with respect to the flow direction (i.e., an angle of 30 degrees with respect to a plane perpendicular to the flow direction). It is preferable that the rear end surface 94a of the outer plate member 94 is inclined at an angle of 40 degrees or more and 80 degrees or less with respect to the flow direction (i.e., an angle of 10 degrees or more and 50 degrees or less with respect to a plane perpendicular to the flow direction). In this embodiment, the inclination angle of the rear end surface 94a of the outer plate member 94 is the same as the inclination angle of the rear end surface 92a of the central plate member 92. In a modified example, the inclination angle of the rear end surface 94 a of the outer plate member 94 may be different from the inclination angle of the rear end surface 92 a of the central plate member 92 .

[0046] A plurality of notches 98 are formed in the front end portion of the central plate member 92 and the front end portion of the outer plate member 94. The notches 98 are recessed rearward from the front end portion of the central plate member 92 and the front end portion of the outer plate member 94. The notches 98 form the noise suppression mechanism 88.

[0047] The surface roughness Ra of each of the rear end surface 92a of the central plate member 92 and the rear end surface 94a of the outer plate member 94 is 0.1 or more, and in this embodiment, the surface roughness Ra of each of the rear end surface 92a of the central plate member 92 and the rear end surface 94a of the outer plate member 94 is 0.1. The surface roughness Ra represents the arithmetic mean roughness. In a modified example, the surface roughness Ra of each of the rear end surface 92a of the central plate member 92 and the rear end surface 94a of the outer plate member 94 may be 0.2 or more and 8 or less. In this embodiment, the access prevention member 84 including the central plate member 92 and the outer plate member 94 is manufactured by mold molding, and the surface roughness Ra of each of the rear end surface 92a of the central plate member 92 and the rear end surface 94a of the outer plate member 94 is adjusted by forming a grain on the inner surface of the molding die. In a modified example, the surface roughness Ra of each of the rear end surfaces 92a of the central plate member 92 and the rear end surfaces 94a of the outer plate members 94 may be adjusted by, for example, sandblasting each of the rear end surfaces 92a of the central plate member 92 and the rear end surfaces 94a of the outer plate members 94, or by filing each of the rear end surfaces 92a of the central plate member 92 and the rear end surfaces 94a of the outer plate members 94. In this embodiment, the portions of the central plate member 92 and the outer plate members 94 having a surface roughness Ra of 0.1 form the noise reduction mechanism 88. In a modified example, the noise reduction mechanism 88 may include portions of the central plate member 92 and the outer plate members 94 having a surface roughness Ra of 0.1 or more, or may include portions of the central plate member 92 and the outer plate members 94 having a surface roughness Ra of 0.2 or more and 8 or less.

[0048] Next, the blowing operation of the blower 2 will be described. As shown in FIG. 2, when the grip 14 is held by an operator and the operator presses the trigger 24 to rotate the motor 70, the fan 74 rotates around the shaft 70a. This causes air to flow into the fan housing chamber 40 from the intake port 62. The air that has flowed into the fan housing chamber 40 is sent outward in the radial direction of the central axis AX by the fan 74 and passes through the air flow path 42. As shown in FIG. 3, the air flowing through the air flow path 42 flows toward the discharge port 64 and then flows into the nozzle pipe 82. As shown in FIG. 4, the air that has flowed into the nozzle pipe 82 flows around the access prevention member 84. The rear end surface 92a of the central plate member 92 and the rear end surface 94a of the outer plate member 94 are located upstream in the flow direction as they move toward the inside in the radial direction of the nozzle pipe 82, so that the position and distribution of turbulence in the flow direction change in the radial direction of the nozzle pipe 82. Furthermore, turbulence is generated as the air flows along the notches 98 formed in the front end of the central plate member 92 and the front end of the outer plate member 94. This suppresses the generation of noise even when the air flows through the nozzle pipe 82 within the set flow rate of the blower 2. The air that flows around the access prevention member 84 blows out from the tip opening of the nozzle pipe 82.

[0049] (effect) In this embodiment, the blower 2 has a fan 74 and an outlet 64, and includes a casing 4 that houses the fan 74, and a nozzle 80 that can be attached to the outlet 64. As shown in Fig. 4, the nozzle 80 includes a nozzle tube 82 through which air flows, and plate members 92, 94 that are arranged inside the nozzle tube 82. Rear end faces 92a, 94a of the plate members 92, 94 are inclined with respect to the flow direction of air flowing inside the nozzle tube 82.

[0050] The air that flows into the nozzle pipe 82 flows around the plate members 92, 94. This generates a turbulent flow. If the rear end faces of the plate members are not inclined with respect to a plane perpendicular to the flow direction, the turbulent flow may generate noise in a narrow specific frequency range. In the above configuration, the rear end faces 92a, 94a of the plate members 92, 94 are inclined with respect to the flow direction, so that the position and distribution where the turbulent flow occurs can be changed with respect to the flow direction. This makes it possible to suppress the generation of noise.

[0051] Furthermore, rear end faces 92a, 94a of the plate members 92, 94 are positioned more upstream in the flow direction as they move radially inward of the nozzle pipe 82.

[0052] In the above configuration, the rear end faces 92a, 94a of the plate members 92, 94 are positioned more upstream in the flow direction as they move radially inward of the nozzle pipe 82, so that the position and distribution of turbulent flow in the flow direction can be changed in the radial direction of the nozzle pipe 82. This can further suppress the generation of noise.

[0053] Further, rear end faces 92a, 94a of the plate members 92, 94 are inclined at an angle of 30 degrees or more and 85 degrees or less with respect to the flow direction.

[0054] If the rear end faces 92a, 94a of the plate members 92, 94 are inclined at an angle of less than 30 degrees with respect to the flow direction, the strength of the plate members 92, 94 is insufficient. Also, if the rear end faces 92a, 94a of the plate members 92, 94 are inclined at an angle of more than 85 degrees, the generation of noise cannot be sufficiently suppressed. With the above configuration, the generation of noise can be suppressed while ensuring the strength of the access prevention member 84.

[0055] Additionally, the plate members 92 , 94 have a notch 98 .

[0056] In the above-described configuration, the simple configuration of providing notches 98 in plate members 92, 94 can change the location and distribution of turbulent flow, thereby making it possible to suppress the generation of noise.

[0057] Furthermore, the plate members 92 and 94 have portions formed thereon whose surface roughness is 0.1 or more.

[0058] If the plate members 92, 94 do not have a portion with a surface roughness Ra of 0.1 or more, the generation of noise cannot be sufficiently suppressed. With the above configuration, the position and distribution of turbulent flow changes, thereby making it possible to suppress the generation of noise.

[0059] Moreover, the width W1 of the plate members 92, 94 in the flow direction is 10% or more of the inner diameter D1 of the nozzle pipe .

[0060] If the width W1 of the plate members 92, 94 is smaller than 10% of the inner diameter D1 of the nozzle pipe 82, the strength of the plate members 92, 94 is insufficient.

[0061] When the nozzle 80 is viewed in the flow direction, the thickness T1 of the plate members 92, 94 is not less than 1% and not more than 8% of the inner diameter D1 of the nozzle pipe .

[0062] If the thickness T1 of the plate members 92, 94 is smaller than 1% of the inner diameter D1 of the nozzle pipe 82, the strength of the plate members 92, 94 is insufficient. Also, if the thickness T1 of the plate members 92, 94 is larger than 8% of the inner diameter D1 of the nozzle pipe 82, the flow path resistance within the nozzle pipe 82 increases. With the above configuration, the strength of the plate members 92, 94 is ensured, and the flow path resistance of the nozzle pipe 82 can be prevented from becoming too large.

[0063] (Correspondence) The central plate member 92 and the outer plate members 94 are examples of "plate members."

[0064] (Second Example) A second embodiment will be described with reference to FIG. 7 and FIG. 8. In the second embodiment, differences from the first embodiment will be described, and the same reference numerals will be used for the same parts as in the first embodiment, and the description will be omitted. The nozzle 80 described in the first embodiment can be applied to the blower 102 of this embodiment. The configuration of the blower 102 excluding the nozzle 80 will be described below. As shown in FIG. 7, the blower 102 includes a casing 104 and a trigger 124. The casing 104 includes a main casing 106, a front connecting portion 110, a rear connecting portion 112, and a grip 114. The rear end opening of the main casing 106 is covered by a cover member 128. The cover member 128 has a plurality of intake ports 128a. The plurality of intake ports 128a penetrate the cover member 128 in the thickness direction. An outlet port 164 is formed at the front end of the main casing 106. The nozzle 80 is attached to the outlet port 164. The front connection part 110 extends upward from the front upper part of the main casing 106. The rear connection part 112 extends upward from the rear upper part of the main casing 106. A battery pack B is removably attached to the rear connection part 112. The grip 114 extends from the rear upper part of the front connection part 110 to the front upper part of the rear connection part 112. A trigger 124 is attached to the grip 114.

[0065] As shown in FIG. 8, the blower 102 includes a motor housing 168, a motor 170, a fan 174, and a stator vane 176. The motor housing 168, the motor 170, the fan 174, and the stator vane 176 are disposed inside the main casing 106. The motor housing 168 is fixed to the main casing 106. The motor 170 is disposed inside the motor housing 168. The motor 170 has a configuration similar to that of the motor 70 of the first embodiment. The rear end of the shaft 170a of the motor 170 protrudes rearward from the rear end of the motor housing 168. The fan 174 is fitted to the rear end of the shaft 170a. The fan 174 is an axial flow fan. When the shaft 170a rotates, the fan 174 rotates. The fan 174 pressurizes and sends air from the rear side to the front side, so that the air flows through the air flow passage 142 formed inside the main casing 106 from the rear end opening toward the outlet 164 .

[0066] The stator vanes 176 are disposed downstream of the fan 174 in the air flow direction and upstream of the access prevention member 84 in the air flow direction. The stator vanes 176 are formed as a separate body from the access prevention member 84. The stator vanes 176 are disposed closer to the fan 174 side than the access prevention member 84 in the air flow direction. Although not shown, the stator vanes 176 have a plurality of fins, which are disposed at equal intervals along the circumferential direction of the outer circumferential surface of the motor housing 168. The stator vanes 176 smooth out the flow of air compressed by the fan 174. As a result, air whose flow has been smoothed by the stator vanes 176 flows inside the nozzle pipe 82 of the nozzle 80.

[0067] (Third Example) The third embodiment will be described with reference to FIG. 9. In the third embodiment, differences from the first embodiment will be described, and the same reference numerals will be used to denote the same parts as in the first embodiment, and the description thereof will be omitted. In the third embodiment, the direction of inclination of the rear end surface 92a of the central plate member 92 is different from the direction of inclination of the rear end surface 92a of the central plate member 92 in the first embodiment, and the direction of inclination of the rear end surface 94a of the outer plate member 94 is different from the direction of inclination of the rear end surface 94a of the outer plate member 94 in the first embodiment. The center of the rear end surface 92a of the central plate member 92 is located on the most downstream side, and both ends of the rear end surface 92a of the central plate member 92 are located on the most upstream side. The rear end surface 92a of the central plate member 92 is located downstream in the flow direction as it moves toward the inside of the radial direction of the nozzle pipe 82. The rear end surface 92a of the central plate member 92 is inclined at an angle of 30 degrees or more and 85 degrees or less with respect to the flow direction (i.e., an angle of 5 degrees or more and 60 degrees or less with respect to a plane perpendicular to the flow direction), and in this embodiment, the rear end surface 92a of the central plate member 92 is inclined at an angle of 60 degrees with respect to the flow direction (i.e., an angle of 30 degrees with respect to a plane perpendicular to the flow direction). Note that it is desirable for the rear end surface 92a of the central plate member 92 to be inclined at an angle of 40 degrees or more and 80 degrees or less with respect to the flow direction (i.e., an angle of 10 degrees or more and 50 degrees or less with respect to a plane perpendicular to the flow direction).

[0068] The rear end surface 94a of the outer plate member 94 is located downstream in the flow direction as it moves toward the inside in the radial direction of the nozzle pipe 82. The rear end surface 94a of the outer plate member 94 is inclined at an angle of 30 degrees or more and 85 degrees or less with respect to the flow direction (i.e., an angle of 5 degrees or more and 60 degrees or less with respect to a plane perpendicular to the flow direction), and in this embodiment, the rear end surface 94a of the outer plate member 94 is inclined at an angle of 60 degrees with respect to the flow direction (i.e., an angle of 30 degrees with respect to a plane perpendicular to the flow direction). It is preferable that the rear end surface 94a of the outer plate member 94 is inclined at an angle of 40 degrees or more and 80 degrees or less with respect to the flow direction (i.e., an angle of 10 degrees or more and 50 degrees or less with respect to a plane perpendicular to the flow direction). The notch 98 is formed in the rear end surface 92a of the central plate member 92 and the rear end surface 94a of the outer plate member 94.

[0069] In this embodiment, rear end faces 92a, 94a of the plate members 92, 94 are positioned downstream in the flow direction as they move radially inward of the nozzle pipe 82.

[0070] In the above configuration, when the rear end faces 92a, 94a of the plate members 92, 94 are located downstream in the flow direction toward the radially inner side of the nozzle pipe 82, the position and distribution of turbulent flow in the flow direction can be changed in the radial direction of the nozzle pipe 82. This can further suppress the generation of noise.

[0071] (Fourth Example) The fourth embodiment will be described with reference to FIG. 10. In the fourth embodiment, differences from the first embodiment will be described, and the same reference numerals will be used to denote the same parts as in the first embodiment, and the description thereof will be omitted. In the fourth embodiment, the access prevention member 84 further has a plurality of slits 286. The slits 286 are formed in both the central plate member 92 and the outer plate member 94. The slits 286 penetrate the central plate member 92 from the rear end surface 92a of the central plate member 92 toward the front end (i.e., in the flow direction). The slits 286 also penetrate the outer plate member 94 from the rear end surface 94a of the outer plate member 94 toward the front end (i.e., in the flow direction). The slits 286 extend parallel to the flow direction. In a modified example, the slits 286 may extend at an angle to the flow direction. When air flows inside the nozzle pipe 82, the air can flow through the slits 286.

[0072] In this embodiment, the blower 2 has a fan 74 and an outlet 64, and includes a casing 4 that houses the fan 74, and a nozzle 80 that can be attached to the outlet 64. The nozzle 80 includes a nozzle tube 82 through which air flows, and plate members 92, 94 that are disposed inside the nozzle tube 82. The plate members 92, 94 have slits 286 that penetrate the plate members 92, 94 in the flow direction of air flow inside the nozzle tube 82.

[0073] If the plate members 92, 94 do not have the slits 286, turbulence may occur, causing noise in a narrow specific frequency range. In the above configuration, since the plate members 92, 94 have the slits 286, air flows through the slits 286 in addition to flowing around the plate members 92, 94. Compared to a case in which the plate members 92, 94 do not have the slits 286, the position and distribution in which turbulence occurs can be changed. This makes it possible to suppress the generation of noise.

[0074] (Modification of the fourth embodiment) In the modified example of the fourth embodiment, the rear end surface 92a of the central plate member 92 and the rear end surface 94a of the outer plate member 94 are not inclined. That is, the rear end surface 92a of the central plate member 92 and the rear end surface 94a of the outer plate member 94 are arranged parallel to a plane perpendicular to the flow direction.

[0075] (Fifth Example) A fifth embodiment will be described. In the fifth embodiment, differences from the first embodiment will be described, and similar parts to the first embodiment will be denoted by the same reference numerals and will not be described. In the fifth embodiment, the access prevention member 84 has a dimple instead of the notch 98. The dimples are formed on both the central plate member 92 and the outer plate member 94. The dimples are disposed near the front end of the central plate member 92 and near the front end of the outer plate member 94. The dimples are recessed from the side surface of the central plate member 92 and the side surface of the outer plate member 94.

[0076] In this embodiment, the plate members 92, 94 have dimples.

[0077] In the above-described configuration, the simple structure of providing dimples on the plate members 92, 94 changes the location and distribution of turbulent flow, thereby making it possible to suppress the generation of noise.

[0078] In one embodiment, the access prevention member 84 does not have to have a notch 98 formed therein. Additionally, the access prevention member 84 does not have to have a dimple formed therein.

[0079] The access preventing member 84 according to one embodiment may not include a portion having a surface roughness Ra of 0.1 or more. Also, the entire surface roughness Ra of the access preventing member 84 may be 0.1 or more.

[0080] The number of central plate members 92 according to an embodiment is not limited to four, and may be three or less, or five or more. The number of outer plate members 94 according to an embodiment is not limited to four, and may be three or less, or five or more.

[0081] The access prevention member 84 according to one embodiment may include only the outer plate member 94. In this case, when the outer plate member 94 is viewed in the flow direction, the outer plate member 94 may extend from a first position on the inner surface of the nozzle pipe 82 to a second position on the inner surface of the nozzle pipe 82. The first position is spaced 180 degrees from the second position in the circumferential direction of the inner surface of the nozzle pipe 82. The rear end surface 94a of the outer plate member 94 may be inclined at a certain angle with respect to the flow direction. In addition, the rear end surface 94a of the outer plate member 94 may be located on the upstream side in the flow direction as it moves from the first position to the second position. In addition, the rear end surface 94a of the outer plate member 94 may be located on the downstream side in the flow direction as it moves from the first position to the second position. [Explanation of symbols]

[0082] 2, 102: Blower 4, 104: Casing 6, 106: Main casing 14, 114: Grip 24, 124: Trigger 32: Housing 34: Volute 40: Fan Containment Room 42, 142: Air flow path 60: Motor housing room 62: Air intake 64, 164: Discharge port 70, 170: Motor 70a, 170a: shaft 72: Control board 74, 174: Fan 80: Nozzle 82: Nozzle pipe 84: Access prevention components 84a, 92a, 94a: Rear end surface 88: Noise suppression mechanism 92: Center plate member 94:Outer plate member 98: Notch 176: Stator blade 286: Slit B: Battery pack

Claims

1. A blower for blowing away fallen leaves on the ground, With fans, a casing having an outlet and housing the fan; a nozzle attachable to the outlet, The nozzle is A nozzle tube through which air flows; a plate member disposed inside the nozzle pipe, The plate member is Two side surfaces that are integral and arranged along a flow direction of air flowing inside the nozzle pipe; and a rear end surface connecting the rear ends of the two side surfaces, The rear end surface of the plate member is inclined with respect to the flow direction.

2. The blower according to claim 1 , wherein the rear end surface of the plate member is positioned more upstream in the flow direction as it moves radially inward of the nozzle pipe.

3. The blower according to claim 1 , wherein the rear end surface of the plate member is positioned downstream in the flow direction as it moves radially inward of the nozzle pipe.

4. 4. The blower according to claim 1, wherein the rear end surface of the plate member is inclined at an angle of 30 degrees or more and 85 degrees or less with respect to the flow direction.

5. The blower according to claim 1 , wherein the plate member has a slit penetrating the plate member in the flow direction.

6. A blower for blowing away fallen leaves on the ground, With fans, a casing having an outlet and housing the fan; a nozzle attachable to the outlet, The nozzle is A nozzle tube through which air flows; a plate member disposed inside the nozzle pipe, The plate member is Two side surfaces that are integral and arranged along a flow direction of air flowing inside the nozzle pipe; a rear end surface connecting the rear ends of the two side surfaces; a front end portion connecting the front ends of the two sides, the plate member has a slit penetrating the plate member from the rear end surface to the front end surface in the flow direction.

7. 7. The blower of claim 1, wherein the plate member has a notch.

8. The blower of claim 1 , wherein the plate member has dimples.

9. The blower according to claim 1 , wherein the plate member has a portion having a surface roughness of 0.1 or more.

10. 10. The blower according to claim 1, wherein a width of the plate member in the flow direction is equal to or greater than 10% of an inner diameter of the nozzle pipe.

11. 11. The blower according to claim 1, wherein a thickness of the plate member is 1% to 8% of an inner diameter of the nozzle pipe when the nozzle is viewed in the flow direction.

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