Blower and blower attachment
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MAKITA CORP
- Filing Date
- 2025-01-24
- Publication Date
- 2026-08-05
Smart Images
Figure 2026126646000001_ABST
Abstract
Description
Technical Field
[0001] The technology disclosed in this specification relates to blowers and blower attachments.
Background Art
[0002] Patent Document 1 discloses a blower including a prime mover, a shaft rotationally driven by the prime mover, a fan connected to the shaft, a blower duct housing the fan, an intake port provided at one end of the blower duct, an exhaust port provided at the other end of the blower duct, a shaft housing disposed near the intake port inside the blower duct and rotatably supporting the shaft, a connection plate connecting between the outer surface of the shaft housing and the inner surface of the blower duct, and an intake cover attached to the intake port. The intake cover includes a lattice portion defining a vent hole allowing the flow of air through the intake port. When the direction from the outside to the inside of the blower duct through the intake port is defined as the front direction and the direction from the inside to the outside of the blower duct through the intake port is defined as the rear direction, the connection plate extends along the front-rear direction.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] When the prime mover is driven and the blower performs air blowing, air flows into the blower duct from the outside through the intake port. At this time, when the air flowing into the blower duct hits the rear end of the connection plate, a wind noise is generated at the rear end of the connection plate, which may increase the noise associated with the air blowing of the blower. This specification provides a technology capable of reducing the noise associated with the air blowing of the blower.
Means for Solving the Problems
[0005] The blower disclosed herein comprises a prime mover, a shaft rotationally driven by the prime mover, a fan connected to the shaft, a blower pipe housing the fan, an air intake port provided at one end of the blower pipe, an exhaust port provided at the other end of the blower pipe, a shaft housing positioned inside the blower pipe near the air intake port and rotatably supporting the shaft, a connecting plate connecting the outer surface of the shaft housing and the inner surface of the blower pipe, and an intake cover attached to the air intake port. The intake cover includes a grid portion that defines ventilation holes allowing airflow through the air intake port. When the direction from the outside to the inside of the blower pipe through the air intake port is defined as the forward direction, and the direction from the inside to the outside of the blower pipe through the air intake port is defined as the rearward direction, the connecting plate extends along the front-rear direction. The rear end of the connecting plate faces the front end of the grid portion. When the air intake port is viewed from the rear, the connecting plate is hidden by the grid portion.
[0006] With the above configuration, when viewing the air intake from the upstream side (i.e., the rear) in the direction of airflow, the connecting plate is hidden in the grid. Therefore, the air flowing into the duct is prevented from hitting the rear end of the connecting plate. This suppresses the generation of wind noise at the rear end of the connecting plate, thereby reducing the noise associated with blower operation.
[0007] The blower attachment disclosed herein is used in conjunction with a prime mover. The blower attachment comprises a shaft rotated by the prime mover, a fan connected to the shaft, a blower pipe housing the fan, an air intake port provided at one end of the blower pipe, an exhaust port provided at the other end of the blower pipe, a shaft housing positioned inside the blower pipe near the air intake port and rotatably supporting the shaft, a connecting plate connecting the outer surface of the shaft housing to the inner surface of the blower pipe, and an intake cover attached to the air intake port. The intake cover includes a grid portion that defines ventilation holes allowing airflow through the air intake port. When the direction from the outside to the inside of the blower pipe through the air intake port is defined as the forward direction, and the direction from the inside to the outside of the blower pipe through the air intake port is defined as the rearward direction, the connecting plate extends along the front-rear direction. The rear end of the connecting plate faces the front end of the grid portion. When the air intake is viewed from the rear, the connecting plate is hidden in the grid section.
[0008] With the above configuration, when viewing the air intake from the upstream side (i.e., the rear) in the direction of airflow, the connecting plate is hidden in the grid. Therefore, the air flowing into the duct is prevented from hitting the rear end of the connecting plate. This suppresses the generation of wind noise at the rear end of the connecting plate, thereby reducing the noise associated with the blower attachment's airflow. [Brief explanation of the drawing]
[0009] [Figure 1] This is a view of the blower 2 according to the embodiment, seen from the front, upper, and right. [Figure 2] This figure shows the blower 2 according to the embodiment with the attachment part 6 removed from the main body part 4. [Figure 3] This is a view of the main body 4 of the blower 2 according to the embodiment, in a cross-sectional view perpendicular to the left-right direction. [Figure 4] This is a view of the attachment portion 6 of the blower 2 according to the embodiment, in a cross-sectional view perpendicular to the left-right direction. [Figure 5]This is a view of the rear of the rear case 64 of the blower 2 according to the embodiment, seen from the rear upper left. [Figure 6] This is a view of the rear of the attachment section 6 of the blower 2 according to the embodiment, seen from the rear upper left. [Figure 7] This is a view of the intake cover 76 of the blower 2 according to the embodiment, seen from the front, lower left. [Figure 8] This is a view of the structure near the hole boss 132 and the restricting piece 174 of the blower 2 according to the embodiment, as seen from the front, lower left. [Figure 9] This is a rear view of the attachment part 6 of the blower 2 according to the embodiment. [Figure 10] This is a cross-sectional view along line XX in Figure 9. [Modes for carrying out the invention]
[0010] Representative and non-limiting examples of the present invention are described in detail below with reference to the drawings. This detailed description is intended simply to show those skilled in the art details for carrying out preferred examples of the present invention and is not intended to limit the scope of the invention. Furthermore, the disclosed additional features and inventions may be used separately from or in conjunction with other features and inventions to provide further improved blowers and blower attachments.
[0011] Furthermore, the combinations of features and processes disclosed in the following detailed description are not essential for carrying out the present invention in the broadest sense, and are described solely to illustrate representative examples of the present invention. Moreover, the various features of the following representative examples, as well as the various features described in the claims, do not necessarily have to be combined in the same way as the examples described herein, or in the order listed, to provide additional and useful embodiments of the present invention.
[0012] All features described herein and / or in the claims are intended to be disclosed individually and independently of each other, as limitations to the specific matters described in the original disclosure and in the claims, separate from the features described in the examples and / or in the claims. Furthermore, all descriptions of numerical ranges and groups or clusters are intended to disclose intermediate configurations as limitations to the specific matters described in the original disclosure and in the claims.
[0013] In one or more embodiments, the thickness of the rear end of the connecting plate may be less than or equal to the thickness of the front end of the grid portion.
[0014] If the thickness of the rear end of the connecting plate (i.e., the upstream end of the connecting plate) exceeds the thickness of the front end of the grid (i.e., the downstream end of the grid), air passing near the grid will hit the rear end of the connecting plate. As a result, wind noise will be generated at the rear end of the connecting plate, potentially increasing the noise associated with the blower's airflow. With the above configuration, since the thickness of the rear end of the connecting plate is less than or equal to the thickness of the front end of the grid, air passing near the grid flows without hitting the rear end of the connecting plate. This suppresses the generation of wind noise at the rear end of the connecting plate, thereby reducing the noise associated with the blower's airflow.
[0015] In one or more embodiments, the distance between the rear end of the connecting plate and the front end of the lattice portion in the front-rear direction may be 1.0 mm or less.
[0016] When the distance between the rear end of the connection plate (i.e., the upstream end of the connection plate) and the front end of the grid portion (i.e., the downstream end of the grid portion) exceeds 1.0 mm, the air flowing along the surface of the grid portion peels off from the grid portion at the front end of the grid portion and then hits the rear end of the connection plate. As a result, a turbulent noise is generated at the rear end of the connection plate, and there is a possibility that the noise associated with the blowing of the blower increases. According to the above configuration, since the distance between the front end of the grid portion and the rear end of the connection plate is 1.0 mm or less, it is difficult for the air flowing along the surface of the grid portion to hit the rear end of the connection plate after peeling off from the grid portion at the front end of the grid portion. Thereby, it is possible to suppress the generation of turbulent noise at the rear end of the connection plate, so that the noise associated with the blowing of the blower can be reduced.
[0017] In one or more embodiments, the intake cover may further include a restricting portion that restricts the intake cover from moving in the circumferential direction of the blower pipe by engaging with the shaft housing, and a fastening portion where a fastening member for fastening the intake cover to the shaft housing is disposed. In the radial direction of the blower pipe, each of the restricting portion and the fastening portion may be disposed radially inward of the grid portion.
[0018] According to the above configuration, elements (i.e., the restricting portion and the fastening portion) for fixing the position of the intake cover with respect to the shaft housing are concentrated near the central axis of the blower pipe. Thereby, the size of the shaft housing in the radial direction of the blower pipe can be made compact.
[0019] In one or more embodiments, the intake cover may further include a wall surface that enters the blower pipe and faces the inner surface of the blower pipe, and ribs that project from the wall surface toward the outside in the radial direction of the blower pipe.
[0020] Over time, the material of the intake cover may deteriorate, causing it to deform and warp radially outward relative to the air duct. With the above configuration, when the intake cover deforms and warps radially outward relative to the air duct, the ribs come into contact with the inner surface of the air duct. This prevents the intake cover from deforming further and warping radially outward relative to the air duct.
[0021] In one or more embodiments, the blower may further include an operating rod extending in the front-rear direction, and a rear housing located at the rear of the operating rod and housing the prime mover. The blower pipe may be attached to the front of the operating rod.
[0022] With the above configuration, the user can operate the blower via the control stick. This improves the ease of use of the blower.
[0023] (Examples) As shown in Figures 1 and 2, the blower 2 comprises a main body 4 and an attachment 6. The attachment 6 is detachably attached to the main body 4. The attachment 6 is a blower attachment used in conjunction with a prime mover (in this embodiment, an electric motor 36 shown in Figure 3). The main body 4 can be fitted with attachments other than the attachment 6 (for example, an attachment for a brush cutter). Therefore, the main body 4 can also be used with other implements (for example, a brush cutter) other than the blower 2.
[0024] The main body 4 comprises an operating rod 8, a loop handle 10, a locking unit 12, a grip unit 14, and a rear housing 16. The operating rod 8 has a hollow pipe shape and extends in a straight line. In this embodiment, the direction parallel to the longitudinal direction of the operating rod 8, from the main body 4 toward the attachment unit 6, is defined as the forward direction, and the direction from the attachment unit 6 toward the main body 4 is defined as the rear direction. Furthermore, the direction perpendicular to the front-rear direction, in which the trigger 32 (described later) is pressed, is defined as the upward direction, and the opposite direction is defined as the downward direction. Furthermore, the direction perpendicular to the front-rear and up-down directions, in which the tip of the sub-grip 34 (described later) points, is defined as the left direction, and the opposite direction is defined as the right direction.
[0025] The locking unit 12 is located at the front of the operating rod 8. The locking unit 12 comprises a connecting cylinder 18, a locking lever 20, and a lock release button 22. The connecting cylinder 18 is fixed to the front of the operating rod 8. The connecting cylinder 18 has a cylindrical shape that opens forward. The rear part of the connecting rod 66 of the attachment part 6 is inserted into the connecting cylinder 18. The locking lever 20 is rotatably attached to the connecting cylinder 18. The lock release button 22 is located on the upper surface of the connecting cylinder 18. As shown in Figure 1, when the locking lever 20 is laid approximately parallel to the operating rod 8 and the lock release button 22 is not pressed, the connecting rod 66 is fixed to the connecting cylinder 18. That is, it is not possible to remove the connecting rod 66 from the connecting cylinder 18. From this state, by raising the lock lever 20 approximately perpendicular to the operating rod 8 and pressing the release button 22, the connecting rod 66 can be removed from the connecting cylinder 18. As shown in Figure 2, by removing the connecting rod 66 from the connecting cylinder 18, the attachment part 6 can be removed from the operating rod 8. Alternatively, with the lock lever 20 raised approximately perpendicular to the operating rod 8, the connecting rod 66 can be inserted into the connecting cylinder 18, and then the lock lever 20 can be pushed down approximately parallel to the operating rod 8 to attach the attachment part 6 to the operating rod 8 (see Figure 1). In this way, the attachment part 6 is attached to and detached from the operating rod 8 via the lock unit 12.
[0026] The grip unit 14 is located at the rear of the operating rod 8. The grip unit 14 includes a grip housing 24. The grip housing 24 is made of a resin material formed to cover the outer circumferential surface of the operating rod 8. The operating rod 8 passes through the grip housing 24. A lever 26 is provided on the upper surface of the grip housing 24. On the upper surface of the grip housing 24, in front of the lever 26, there is an operating section 28 and a display section 30. The display section 30 displays the operating status of the blower 2, etc. The operating section 28 is equipped with a power switch for switching the main power of the blower 2 on / off. A trigger 32 is provided at the bottom of the grip housing 24. The trigger 32 is a component for the user to switch the drive / stop of the electric motor 36 (see Figure 3). When the lever 26 is not pressed down by the user, the user is prohibited from pressing down the trigger 32. On the other hand, when the lever 26 is pressed down by the user, the user is permitted to press down the trigger 32. The user can drive the electric motor 36 (see Figure 3) by pressing the lever 26 with the palm of the hand gripping the grip housing 24, and simultaneously pressing the trigger 32 with the fingers of the same hand.
[0027] In the operating rod 8, a loop handle 10 for the user to grip is provided between the lock unit 12 and the grip unit 14. The loop handle 10 is a hollow pipe shape and is formed in a loop shape that bulges upward and to the side of the operating rod 8. A sub-grip 34 extending forward and to the left is fixed to the lower left of the loop handle 10. The user can carry the blower 2 by gripping the grip housing 24 with one hand (for example, the right hand) and gripping the loop handle 10 or the sub-grip 34 with the other hand (for example, the left hand).
[0028] As shown in Figure 3, the rear housing 16 houses an electric motor 36 and a control board 38 that controls the operation of the electric motor 36. A battery pack B is detachably mounted on the rear of the rear housing 16. The control board 38 controls the operation of the electric motor 36 by controlling the power supplied to the electric motor 36 from the battery pack B. The electric motor 36 is an inner-rotor type brushless motor comprising a motor shaft 40, a rotor 42 fixed to the motor shaft 40, and a stator 44 positioned radially outward from the rotor 42. The motor shaft 40 is connected to the rear of a first transmission shaft 48 that extends into the interior of the operating rod 8 via a reduction gear 46 housed in the rear housing 16. The operating rod 8 rotatably supports the first transmission shaft 48.
[0029] As shown in Figure 4, the attachment section 6 comprises a front case 62, a rear case 64, a connecting rod 66, a second transmission shaft 68, a third transmission shaft 70, a fan 72, a rectifier member 74, and an intake cover 76. As shown in Figure 1, the front case 62 and the rear case 64 are fixed to each other by a first screw 78. As shown in Figure 4, the front case 62 and the rear case 64 define a blower pipe 80 through which air flows. An intake port 82 is formed at the rear end of the rear case 64, through which air flows from the outside to the inside of the blower pipe 80. An exhaust port 84 is formed at the front end of the front case 62, through which air flows from the inside to the outside of the blower pipe 80. The central axis CX of the blower pipe 80 extends along the front-rear direction.
[0030] The front case 62 comprises a case body 92 and an end pipe 94 that is movable in the front-rear direction relative to the case body 92. The end pipe 94 is located at the front end of the front case 62 and is equipped with an exhaust port 84. The length of the air blower pipe 80 can be adjusted by moving the end pipe 94 relative to the case body 92.
[0031] The rear case 64 comprises a tubular body 102, a shaft housing 104, and eight connecting plates 106 (partially not shown). The tubular body 102, the shaft housing 104, and the eight connecting plates 106 are formed integrally without seams. The tubular body 102, together with the front case 62, defines the air supply pipe 80. The shaft housing 104 rotatably supports the third transmission shaft 70. The eight connecting plates 106 connect the inner surface of the tubular body 102 to the outer surface of the shaft housing 104. The shaft housing 104 comprises an outer shell portion 108 connected to the eight connecting plates 106, a shaft support portion 110 supporting the third transmission shaft 70, a clamp cylinder 112 into which the connecting rod 66 is inserted, and three screw bosses 114 (partially not shown) to which the intake cover 76 is fastened. The shaft support portion 110 rotatably supports the third transmission shaft 70 via bearings 111a and 111b.
[0032] As shown in Figure 5, the outer surface of the outer shell 108 has a dome shape that widens radially outward from the central axis CX as it moves from the rear to the front. The eight connecting plates 106 extend perpendicularly to the inner surface of the tube 102 and the outer surface of the outer shell 108, respectively. The eight connecting plates 106 are arranged at equal intervals in the circumferential direction of the central axis CX. The rear end surface 106a of each of the eight connecting plates 106 extends parallel to the radial direction of the central axis CX from the outer surface of the rear end of the outer shell 108, then bends forward and extends to the inner surface of the tube 102.
[0033] The clamp cylinder 112 comprises a cylindrical body 120 having a slit 118, and fastening pieces 122 positioned on both sides of the slit 118 at the lower part of the cylindrical body 120. The cylindrical body 120 is open to the rear. The front part of the connecting rod 66 (see Figure 4) is inserted into the cylindrical body 120. The cylindrical body 120 has a screw hole 124. The connecting rod 66 has a through hole (not shown) at a position corresponding to the screw hole 124. A second screw 126 (see Figure 6) is screwed into the screw hole 124. When the second screw 126 is screwed into the screw hole 124, the tip of the second screw 126 that has passed through the screw hole 124 is inserted into the through hole of the connecting rod 66. This prevents the position of the connecting rod 66 relative to the clamp cylinder 112 from shifting in the front-rear direction, and prevents the connecting rod 66 from rotating relative to the clamp cylinder 112. Furthermore, the left fastening piece 122 has a through hole 128. The right fastening piece 122 has a screw hole 129 (see Figure 4) at a position opposite to the through hole 128 of the left fastening piece 122. A third screw 130 (see Figure 6), which has passed through the through hole 128, is screwed into the screw hole 129. When the third screw 130 is screwed into the screw hole 129 with the through hole 128 still in place, the fastening pieces 122 move closer together, reducing the width of the slit 118 and the inner diameter of the cylinder body 120. As a result, the connecting rod 66 is clamped to the inner surface of the clamp cylinder 112.
[0034] The three screw bosses 114 are positioned radially outward from the cylindrical body 120 of the clamp cylinder 112 and radially inward from the rear end of the outer shell portion 108. One screw boss 114 is positioned above the clamp cylinder 112, one to the left of the left fastening piece 122, and one to the right of the right fastening piece 122. The three screw bosses 114 are positioned at equal intervals in the circumferential direction of the central axis CX.
[0035] As shown in Figure 4, the connecting rod 66 has a hollow pipe shape and extends in a straight line. The connecting rod 66 rotatably supports the second transmission shaft 68. The second transmission shaft 68 extends in the front-rear direction so as to pass inside the connecting rod 66. The rear end of the second transmission shaft 68 is connected to the front end of the first transmission shaft 48 (see Figure 3), which passes inside the operating rod 8 (see Figure 3). The front end of the second transmission shaft 68 extends into the internal space of the shaft support 110 and is connected to the rear end of the third transmission shaft 70. The front end of the third transmission shaft 70 protrudes forward of the shaft housing 104.
[0036] The fan 72 is positioned in front of the shaft housing 104. The fan 72 comprises a hub 142 connected to the front of the third transmission shaft 70, and a plurality of rotor blades 144 protruding from the outer surface of the hub 142. The hub 142 and the plurality of rotor blades 144 are formed integrally without seams. The outer surface of the hub 142 has a cylindrical shape. The outer surface of the hub 142 is flush with the outer surface near the front end of the outer shell portion 108 of the shaft housing 104. When the electric motor 36 (see Figure 3) is driven, the motor shaft 40 (see Figure 3) rotates. The rotation of the motor shaft 40 is transmitted to the fan 72 via the reduction gear 46 (see Figure 3), the first transmission shaft 48 (see Figure 3), the second transmission shaft 68, and the third transmission shaft 70. This causes the fan 72 to rotate. When the fan 72 rotates, an airflow is generated inside the air duct 80 from the intake port 82 to the exhaust port 84 (i.e., an airflow from rear to front). As a result, air from outside the air duct 80 is drawn into the air duct 80 through the intake port 82, and air from inside the air duct 80 is discharged to the outside of the air duct 80 through the exhaust port 84.
[0037] The rectifier member 74 is positioned in front of the fan 72. The rectifier member 74 comprises an outer frame 146, a cone 148, and a plurality of stator vanes 150. The outer frame 146, the cone 148, and the plurality of stator vanes 150 are formed integrally without seams. The outer frame 146 is fixed to the front case 62 and the rear case 64, respectively, in contact with a stepped portion 64a formed on the inner surface of the rear case 64. The inner surface of the outer frame 146 is flush with the inner surface of the pipe 102. The central axis of the cone 148 is coaxial with the central axis CX of the air supply pipe 80. The cone 148 comprises a cylindrical portion 152 on which a plurality of stator vanes 150 are provided, and a reduced diameter portion 154 extending forward from the front end of the cylindrical portion 152. The outer surface of the cylindrical portion 152 is flush with the outer surface of the hub 142. The reduced diameter section 154 decreases in diameter as it extends forward. Multiple stationary vanes 150 connect the inner surface of the outer frame 146 to the outer surface of the cone 148.
[0038] As shown in Figure 7, the intake cover 76 comprises a cup portion 162, a flange portion 164, a first circumferential wall portion 165, a grid portion 166, a second circumferential wall portion 168, an outer peripheral portion 170, and leg portions 172. The cup portion 162, flange portion 164, first circumferential wall portion 165, grid portion 166, second circumferential wall portion 168, outer peripheral portion 170, and leg portions 172 are formed integrally without seams. The cup portion 162 has a shape that follows the rear end and outer circumference of the clamp cylinder 112 (see Figure 5). The cup portion 162 covers the rear end and outer circumference of the clamp cylinder 112. The flange portion 164 is connected to the front end of the cup portion 162 and extends radially along the central axis CX. The flange portion 164 covers the rear of the three screw bosses 114 (see Figure 5). Three hole bosses 132 and three restricting pieces 174 are formed on the front surface of the flange portion 164. The three hole bosses 132 and the three restricting pieces 174 are formed in positions corresponding to the three screw bosses 114 (see Figure 5) of the shaft housing 104. The three hole bosses 132 are adjacent to the first circumferential wall portion 165. The first circumferential wall portion 165 extends forward from the outer peripheral edge of the flange portion 164.
[0039] As shown in Figure 6, a fourth screw 134 is positioned in each of the three hole bosses 132. The fourth screw 134 passes through the through hole 132a of the hole boss 132 (see Figure 7) and is then screwed into the screw hole 114a of the screw boss 114 (see Figure 5). This fastens the intake cover 76 to the shaft housing 104.
[0040] As shown in Figure 8, the restricting piece 174 has a shape like a split cylinder. The restricting piece 174 extends forward beyond the front surface of the hole boss 132. The restricting piece 174 is positioned to obstruct the space between the central axis CX (see Figure 7) and the central axis of the through hole 132a. The outer circumferential surface of the restricting piece 174 is oriented radially inward of the central axis CX. The inner circumferential surface of the restricting piece 174 is oriented radially outward of the central axis CX. The inner circumferential surface of the restricting piece 174 has a shape that conforms to the outer circumferential surface of the screw boss 114 (see Figure 5) of the shaft housing 104. The inner circumferential surface of the restricting piece 174 fits onto the outer circumferential surface of the screw boss 114 (i.e., the restricting piece 174 engages with the screw boss 114), thereby restricting the intake cover 76 from moving in the circumferential direction of the central axis CX relative to the shaft housing 104. Furthermore, a crushing rib 176 extending in the front-to-back direction is formed on the inner circumferential surface of the regulating piece 174. The crushing rib 176 abuts against the outer circumferential surface of the screw boss 114, thereby suppressing looseness between the regulating piece 174 and the screw boss 114.
[0041] As shown in Figure 9, the grid section 166 is positioned radially outward from the first circumferential wall section 165 along the central axis CX. The grid section 166 comprises eight radial grids 178 extending radially along the central axis CX and three circumferential grids 180 extending circumferentially along the central axis CX. The eight radial grids 178 connect the outer circumferential surface of the first circumferential wall section 165 to the inner circumferential surface of the second circumferential wall section 168. The three circumferential grids 180 intersect with each of the eight radial grids 178. The grid section 166 prevents the user's hand from entering the inside of the air duct 80. Ventilation holes 182 are defined between the grid sections 166, penetrating the intake cover 76 in the front-rear direction.
[0042] As shown in Figure 6, the eight radial grids 178 are arranged so as to be aligned front to back with the eight connecting plates 106. Therefore, the eight radial grids 178 are arranged at equal intervals in the circumferential direction of the central axis CX. The front end surface 178a of the radial grid 178 has a shape that follows the rear end surface 106a of the connecting plate 106. Specifically, the front end surface 178a of the radial grid 178 extends parallel to the radial direction of the central axis CX from the outer circumferential surface of the first circumferential wall portion 165, then bends forward and extends to the inner circumferential surface of the second circumferential wall portion 168.
[0043] As shown in Figure 10, the front end surface 178a of the radial grid 178 faces the rear end surface 106a of the connecting plate 106. The distance in the front-rear direction between the front end surface 178a of the radial grid 178 and the rear end surface 106a of the connecting plate 106 is in the range of 0.0 mm to 1.0 mm, and in this embodiment it is 0.6 mm. This value is based on the results of measuring the noise generated near the intake cover 76 when the blower 2 is driven. As a result of performing the measurement while changing the distance between the front end surface 178a and the rear end surface 106a, it was found that the noise was significantly reduced when the distance between the front end surface 178a and the rear end surface 106a was 1.0 mm or less, and was reduced even more significantly when it was 0.6 mm or less. The radial grid 178 also includes a thickened section 184 whose thickness increases from rear to front, and a first constant-thickness section 186 which has a substantially constant thickness. The front end of the thickened portion 184 is connected to the rear end of the first constant-thickness portion 186. The front end surface 178a of the radial grid 178 is located at the front end of the first constant-thickness portion 186. The thickness of the first constant-thickness portion 186 (i.e., the thickness of the front end surface 178a) is in the range of 2.0 mm to 2.4 mm, and in this embodiment it is 2.2 mm. The connecting plate 106 also includes a second constant-thickness portion 188 having a substantially constant thickness, and a reduced-thickness portion 190 whose thickness decreases from rear to front. The front end of the second constant-thickness portion 188 is connected to the rear end of the reduced-thickness portion 190. The rear end surface 106a of the connecting plate 106 is located at the rear end of the second constant-thickness portion 188. The thickness of the second constant-thickness portion 188 (i.e., the thickness of the rear end surface 106a) is in the range of 1.4 mm to 2.0 mm, and in this embodiment it is 1.7 mm. The thickness of the second constant thickness section 188 (i.e., the thickness of the rear end surface 106a) is less than or equal to the thickness of the first constant thickness section 186 (i.e., the thickness of the front end surface 178a).
[0044] As shown in Figure 9, when the air intake 82 is viewed from the rear, the eight connecting plates 106 are each hidden by the eight radial grids 178. Therefore, the air flowing into the air supply pipe 80 from the outside through the air intake 82 (i.e., air flowing from rear to front) does not come into contact with the rear end surface 106a (see Figure 5) of the connecting plate 106. This suppresses the generation of wind noise at the rear end surface 106a of the connecting plate 106, and also prevents the airflow from being obstructed by the rear end surface 106a of the connecting plate 106.
[0045] As shown in Figure 5, the rear case 64 is provided with an enlarged diameter section 192 near the rear end of the pipe 102, which widens from front to rear. As shown in Figure 6, the intake cover 76 is attached to the shaft housing 104 with the front surface of the outer circumference 170 in contact with the rear end of the enlarged diameter section 192. The legs 172 protrude downward from the outer surface of the outer circumference 170. The user can place the blower 2 on a mounting surface by bringing the legs 172 of the intake cover 76 and the legs 194 (see Figure 1) formed on the lower surface of the rear housing 16 into contact with the ground or other mounting surface.
[0046] As shown in Figure 7, the second circumferential wall portion 168 is provided with a plurality of anti-warping ribs 196 protruding from the outer circumferential surface of the second circumferential wall portion 168. The plurality of anti-warping ribs 196 extend in the front-rear direction. The outer circumferential surface of the second circumferential wall portion 168 fits inside the enlarged diameter portion 192 (see Figure 5) of the rear case 64 and faces the inner surface of the enlarged diameter portion 192. The plurality of anti-warping ribs 196 are positioned to face the anti-warping pieces 198 (see Figure 5) formed on the inner surface of the enlarged diameter portion 192 of the rear case 64. If the intake cover 76 deforms so as to warp radially outward of the air supply pipe 80, the anti-warping ribs 196 will come into contact with the anti-warping pieces 198. This prevents the intake cover 76 from deforming further so as to warp radially outward of the air supply pipe 80.
[0047] (modified version) (See Figure 1) The blower 2 does not have to have an operating rod 8. That is, the blower 2 may have a main body 4 and an attachment 6 that are inseparably integrated. In this case, the electric motor 36 may be located inside the air duct 80 (for example, inside the shaft housing 104). The attachment 6 does not have to have a connecting rod 66 and a second transmission shaft 68. The intake cover 76 does not have to have a shape that avoids interference with the connecting rod 66. Alternatively, part of the blower 2 may be carried on the user's back.
[0048] (See Figure 1) Blower 2 may be configured to be powered by a power source other than battery pack B. For example, blower 2 may be equipped with a cable and plug for connecting to an external power source, and may be configured to be powered by an external power source.
[0049] (See Figure 3) The blower 2 may be equipped with a prime mover other than the electric motor 36 (for example, an internal combustion engine). Also, the electric motor 36 may be a motor other than an inner rotor type brushless motor (for example, an outer rotor type brushless motor).
[0050] (See Figure 4) The air supply pipe 80 does not have to extend in a straight line; it may be curved. As a result, the direction of airflow at the intake port 82 and the direction of airflow at the exhaust port 84 may be different.
[0051] (See Figures 5 and 7) The connecting plate 106 does not have to extend parallel to the radial direction of the central axis CX. For example, the connecting plate 106 may curve circumferentially as it moves radially outward from the central axis CX. In this case, the radial grid 178 may also curve circumferentially as it moves radially outward from the central axis CX. As a result, when the intake port 82 is viewed from the rear, the connecting plate 106 may be hidden by the radial grid 178.
[0052] (See Figure 10) The distance in the front-rear direction between the front end surface 178a of the radial grid 178 and the rear end surface 106a of the connecting plate 106 may be greater than 1.0 mm.
[0053] (See Figures 5, 7, and 8) The restricting piece 174 and the hole boss 132 may be positioned radially outward of the radial grid 178. For example, the restricting piece 174 and the hole boss 132 may be positioned on the outer circumference 170. In this case, the screw boss 114 may be positioned at the rear end of the pipe body 102 so as to face the hole boss 132. Alternatively, the restricting piece 174 may be positioned radially outward of the central axis CX as viewed from the screw boss 114. Furthermore, the restricting piece 174 may extend around the entire circumference of the hole boss 132.
[0054] (See Figure 7) The second circumferential wall portion 168 of the intake cover 76 does not necessarily have to be equipped with anti-warping ribs 196. That is, the outer circumferential surface of the second circumferential wall portion 168 may be a smooth cylindrical surface.
[0055] (Features of the example) In one or more embodiments, the blower 2 includes an electric motor 36 (example of a prime mover), a third transmission shaft 70 (example of a shaft) rotationally driven by the electric motor 36, a fan 72 connected to the third transmission shaft 70, a blower pipe 80 housing the fan 72, an air intake port 82 provided at one end of the blower pipe 80, an exhaust port 84 provided at the other end of the blower pipe 80, a shaft housing 104 positioned inside the blower pipe 80 near the air intake port 82 and rotatably supporting the third transmission shaft 70, a connecting plate 106 connecting the outer surface of the shaft housing 104 to the inner surface of the blower pipe 80, and an intake cover 76 attached to the air intake port 82. The intake cover 76 includes a radial grid 178 (example of a grid portion) defining vents 182 that allow airflow through the air intake port 82. When the direction from the outside to the inside of the air duct 80 via the air intake port 82 is defined as the forward direction, and the direction from the inside to the outside of the air duct 80 via the air intake port 82 is defined as the rearward direction, the connecting plate 106 extends along the front-rear direction. The rear end surface 106a of the connecting plate 106 faces the front end surface 178a of the radial grid 178. When the air intake port 82 is viewed from the rear, the connecting plate 106 is hidden by the radial grid 178.
[0056] With the above configuration, when the air intake 82 is viewed from the upstream side (i.e., the rear) in the direction of airflow, the connecting plate 106 is hidden by the radial grid 178. As a result, the air flowing into the air supply pipe 80 is prevented from hitting the rear end surface 106a of the connecting plate 106. This suppresses the generation of wind noise at the rear end surface 106a of the connecting plate 106, thereby reducing the noise associated with the blower 2.
[0057] In one or more embodiments, the thickness of the rear end face 106a of the connecting plate 106 is less than or equal to the thickness of the front end face 178a of the radial grid 178.
[0058] If the thickness of the rear end surface 106a of the connecting plate 106 (i.e., the upstream end of the connecting plate 106) exceeds the thickness of the front end surface 178a of the radial grid 178 (i.e., the downstream end of the radial grid 178), air passing near the radial grid 178 will hit the rear end surface 106a of the connecting plate 106. As a result, wind noise will be generated at the rear end surface 106a of the connecting plate 106, which may increase the noise associated with the blower 2. With the above configuration, since the thickness of the rear end surface 106a of the connecting plate 106 is less than or equal to the thickness of the front end surface 178a of the radial grid 178, air passing near the radial grid 178 flows without hitting the rear end surface 106a of the connecting plate 106. This suppresses the generation of wind noise at the rear end surface 106a of the connecting plate 106, and thus reduces the noise associated with the blower 2.
[0059] In one or more embodiments, the distance between the rear end surface 106a of the connecting plate 106 and the front end surface 178a of the radial grid 178 in the front-rear direction is 1.0 mm or less.
[0060] If the distance between the rear end surface 106a of the connecting plate 106 (i.e., the upstream end of the connecting plate 106) and the front end surface 178a of the radial grid 178 (i.e., the downstream end of the radial grid 178) exceeds 1.0 mm, the air flowing along the surface of the radial grid 178 will separate from the radial grid 178 at the front end surface 178a of the radial grid 178 and then hit the rear end surface 106a of the connecting plate 106. As a result, wind noise will be generated at the rear end surface 106a of the connecting plate 106, and the noise associated with the blower 2 may increase. With the above configuration, since the distance between the front end surface 178a of the radial grid 178 and the rear end surface 106a of the connecting plate 106 is 1.0 mm or less, the air flowing along the surface of the radial grid 178 will separate from the radial grid 178 at the front end surface 178a of the radial grid 178 and then is less likely to hit the rear end surface 106a of the connecting plate 106. This suppresses the generation of wind noise at the rear end surface 106a of the connecting plate 106, thereby reducing the noise associated with the blowing of air by the blower 2.
[0061] In one or more embodiments, the intake cover 76 further comprises a restricting piece 174 (example of a restricting portion) that engages with the shaft housing 104 to restrict the intake cover 76 from moving circumferentially relative to the shaft housing 104 in the air duct 80, and a hole boss 132 (example of a fastening portion) in which a fourth screw 134 (example of a fastening member) for fastening the intake cover 76 to the shaft housing 104 is positioned. In the radial direction of the air duct 80, the restricting piece 174 and the hole boss 132 are each positioned radially inward from the radial grid 178.
[0062] According to the above configuration, the elements for fixing the position of the intake cover 76 relative to the shaft housing 104 (i.e., the restricting piece 174 and the hole boss 132) are concentrated near the central axis CX of the blower pipe 80. This makes the size of the shaft housing 104 in the radial direction of the blower pipe 80 more compact.
[0063] In one or more embodiments, the intake cover 76 further comprises an outer surface of a second circumferential wall portion 168 that extends into the interior of the blower pipe 80 and faces the inner surface of the blower pipe 80 (example of a wall surface), and an anti-warping rib 196 (example of a rib) that protrudes radially outward from the outer surface of the second circumferential wall portion 168 toward the blower pipe 80.
[0064] Over time, for example, the material of the intake cover 76 may deteriorate, causing the intake cover 76 to deform and warp radially outward relative to the air blower pipe 80. With the above configuration, if the intake cover 76 deforms and warps radially outward relative to the air blower pipe 80, the anti-warping rib 196 will come into contact with the inner surface of the air blower pipe 80. This prevents the intake cover 76 from deforming further and warping radially outward relative to the air blower pipe 80.
[0065] In one or more embodiments, the blower 2 further comprises an operating rod 8 extending in the front-rear direction, and a rear housing 16 located at the rear of the operating rod 8 and housing an electric motor 36. A blower pipe 80 is attached to the front of the operating rod 8.
[0066] With the above configuration, the user can operate the blower 2 via the control pole 8. This improves the usability of the blower 2.
[0067] In one or more embodiments, the attachment unit 6 (an example of a blower attachment) is used in conjunction with an electric motor 36. The attachment unit 6 comprises a third transmission shaft 70 rotationally driven by the electric motor 36, a fan 72 connected to the third transmission shaft 70, a blower pipe 80 housing the fan 72, an air intake port 82 provided at one end of the blower pipe 80, an exhaust port 84 provided at the other end of the blower pipe 80, a shaft housing 104 positioned inside the blower pipe 80 near the air intake port 82 and rotatably supporting the third transmission shaft 70, a connecting plate 106 connecting the outer surface of the shaft housing 104 and the inner surface of the blower pipe 80, and an intake cover 76 attached to the air intake port 82. The intake cover 76 is provided with a radial grid 178 defining vents 182 that allow airflow through the air intake port 82. When the direction from the outside to the inside of the air duct 80 via the air intake port 82 is defined as the forward direction, and the direction from the inside to the outside of the air duct 80 via the air intake port 82 is defined as the rearward direction, the connecting plate 106 extends along the front-rear direction. The rear end surface 106a of the connecting plate 106 faces the front end surface 178a of the radial grid 178. When the air intake port 82 is viewed from the rear, the connecting plate 106 is hidden by the radial grid 178.
[0068] With the above configuration, when the air intake 82 is viewed from the upstream side (i.e., the rear) in the direction of airflow, the connecting plate 106 is hidden by the radial grid 178. As a result, the air flowing into the air supply pipe 80 is prevented from hitting the rear end surface 106a of the connecting plate 106. This suppresses the generation of wind noise at the rear end surface 106a of the connecting plate 106, thereby reducing the noise associated with airflow in the attachment section 6. [Explanation of symbols]
[0069] 2: Blower, 4: Main body, 6: Attachment, 8: Operating rod, 10: Loop handle, 12: Locking unit, 14: Grip unit, 16: Rear housing, 18: Connecting cylinder, 20: Locking lever, 22: Unlock button, 24: Grip housing, 26: Lever, 28: Operating section, 30: Display section, 32: Trigger, 34: Sub-grip, 36: Electric motor, 38: Control board, 40: Motor shaft, 42: Rotor, 44: Stator, 46 : Reducer, 48: First transmission shaft, 62: Front case, 64: Rear case, 64a: Stepped section, 66: Connecting rod, 68: Second transmission shaft, 70: Third transmission shaft, 72: Fan, 74: Rectifying member, 76: Intake cover, 78: First screw, 80: Blower pipe, 82: Intake port, 84: Exhaust port, 92: Case body, 94: End pipe, 102: Pipe body, 104: Shaft housing, 106: Connecting plate, 106a: Rear end face, 108: Outer shell section, 110: Shaft support section , 111a: Bearing, 111b: Bearing, 112: Clamp tube, 114: Screw boss, 114a: Screw hole, 118: Slit, 120: Tube body, 122: Fastening piece, 124: Screw hole, 126: Second screw, 128: Through hole, 129: Screw hole, 130: Third screw, 132: Hole boss, 132a: Through hole, 134: Fourth screw, 142: Hub, 144: Movable vane, 146: Outer frame, 148: Cone, 150: Stator vane, 152: Cylindrical section, 154: Reduced diameter section, 162: Cup section, 164: Flange section, 165: First circumferential wall section, 166: Grid section, 168: Second circumferential wall section, 170: Outer perimeter section, 172: Leg section, 174: Regulating piece, 176: Crushing rib, 178: Radial grid, 178a: Front end surface, 180: Circumferential grid, 182: Ventilation hole, 184: Enlarged thickness section, 186: First constant thickness section, 188: Second constant thickness section, 190: Reduced thickness section, 192: Enlarged diameter section, 194: Leg section, 196: Anti-warping rib, 198: Anti-warping piece, B: Battery pack, CX: Central axis
Claims
1. The prime mover and A shaft that is rotationally driven by the aforementioned prime mover, A fan connected to the aforementioned shaft, A vent pipe housing the aforementioned fan, An air intake port is provided at one end of the aforementioned air supply pipe, An exhaust port is provided at the other end of the aforementioned air duct, A shaft housing is positioned inside the air supply pipe near the air intake port and rotatably supports the shaft, A connecting plate that connects the outer surface of the shaft housing and the inner surface of the air vent pipe, It comprises an intake cover attached to the aforementioned intake port, The intake cover is provided with a grid portion that defines ventilation holes that allow air to flow through the intake port, When the direction from the outside to the inside of the air duct through the intake port is defined as the forward direction, and the direction from the inside to the outside of the air duct through the intake port is defined as the rearward direction, The aforementioned connecting plate extends along the front-to-back direction, The rear end of the connecting plate faces the front end of the grid portion. When the aforementioned air intake is viewed from the rear, the connecting plate is hidden in the grid section of the blower.
2. The blower according to claim 1, wherein the thickness of the rear end of the connecting plate is less than or equal to the thickness of the front end of the grid portion.
3. The blower according to claim 1 or 2, wherein the distance between the rear end of the connecting plate and the front end of the grid portion in the front-rear direction is 1.0 mm or less.
4. The aforementioned intake cover is, A restricting portion that engages with the shaft housing to restrict the intake cover from moving in the circumferential direction of the air supply pipe relative to the shaft housing, The shaft housing further comprises a fastening portion on which a fastening member for fastening the intake cover is arranged, The blower according to any one of claims 1 to 3, wherein in the radial direction of the air duct, each of the restricting portion and the fastening portion is arranged radially inward from the grid portion.
5. The aforementioned intake cover is, It enters the interior of the air vent and faces the inner surface of the air vent, The blower according to any one of claims 1 to 4, further comprising: ribs protruding radially outward from the wall surface of the air vent pipe.
6. An operating rod that extends in the front-to-back direction, The system further comprises a rear housing provided at the rear of the operating rod, which houses the prime mover, The blower according to any one of claims 1 to 5, wherein the air duct is attached to the front of the operating rod.
7. A blower attachment used in conjunction with a prime mover, A shaft that is rotationally driven by the aforementioned prime mover, A fan connected to the aforementioned shaft, A vent pipe housing the aforementioned fan, An air intake port is provided at one end of the aforementioned air supply pipe, An exhaust port is provided at the other end of the aforementioned air duct, A shaft housing is positioned inside the air supply pipe near the air intake port and rotatably supports the shaft, A connecting plate that connects the outer surface of the shaft housing and the inner surface of the air vent pipe, It comprises an intake cover attached to the aforementioned intake port, The intake cover is provided with a grid portion that defines ventilation holes that allow air to flow through the intake port, When the direction from the outside to the inside of the air duct through the intake port is defined as the forward direction, and the direction from the inside to the outside of the air duct through the intake port is defined as the rearward direction, The aforementioned connecting plate extends along the front-to-back direction, The rear end of the connecting plate faces the front end of the grid portion. When the aforementioned air intake is viewed from the rear, the connecting plate is hidden in the grid portion; this is a blower attachment.