Blower and blower attachment

Abstract

A blower may include: a prime mover; a shaft; a fan; an airflow pipe; an inlet disposed at one end of the airflow pipe; an outlet disposed at another end of the airflow pipe; a shaft housing rotatably supporting the shaft; a connecting plate connecting an outer surface of the shaft housing and an inner surface of the airflow pipe; and an inlet cover attached to the inlet. The inlet cover may include a grille part defining an air hole through which air flows into the inlet. The connecting plate may extend in a front-rear direction. A rear end of the connecting plate may face a front end of the grille part. When the inlet is viewed from the exterior of the airflow pipe in a front-rear direction, the connecting plate may be hidden by the grille part.

Description

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority from Japanese Patent Application No. 2025-010407 filed on January 24, 2025. The entire content of the priority application is incorporated herein by reference.TECHNICAL FIELD

[0002] The art disclosed herein relates to a blower and a blower attachment.BACKGROUND ART

[0003] US Patent Application Publication No. 2008 / 0189904 describes a blower including: a prime mover; a shaft configured to be rotated by the prime mover; a fan coupled to the shaft; an airflow pipe in which the fan is housed; an inlet disposed at one end of the airflow pipe; an outlet disposed at another end of the airflow pipe; a shaft housing located inside the airflow pipe in proximity to the inlet and rotatably supporting the shaft; a connecting plate connecting an outer surface of the shaft housing and an inner surface of the airflow pipe; and an inlet cover attached to the inlet. The inlet cover comprises a grille part defining an air hole through which air flows into the inlet. A direction from an exterior toward an interior of the airflow pipe through the inlet is defined as a front direction, a direction from the interior toward the exterior of the airflow pipe through the inlet is defined as a rear direction, and the connecting plate extends in a front-rear direction.SUMMARY

[0004] When the prime mover is driven such that the blower starts to blow air, air flows through the inlet from the exterior to the interior of the airflow pipe. At this occasion, when the air having flowed into the airflow pipe is blown onto the rear end of the connecting plate, wind noise is generated at the rear end of the connecting plate, by which noise accompanying the airflow from the blower could possibly be loud. The present teachings provide an art configured to allow to decrease noise accompanying airflow from a blower.

[0005] A blower may comprise: a prime mover; a shaft configured to be rotated by the prime mover; a fan coupled to the shaft; an airflow pipe in which the fan is housed; an inlet disposed at one end of the airflow pipe; an outlet disposed at another end of the airflow pipe; a shaft housing located inside the airflow pipe in proximity to the inlet and rotatably supporting the shaft; a connecting plate connecting an outer surface of the shaft housing and an inner surface of the airflow pipe; and an inlet cover attached to the inlet. The inlet cover may comprise a grille part defining an air hole through which air flows into the inlet. A direction from an exterior toward an interior of the airflow pipe through the inlet may be defined as a front direction. A direction from the interior toward the exterior of the airflow pipe through the inlet may be defined as a rear direction. The connecting plate may extend in a front-rear direction. A rear end of the connecting plate may face a front end of the grille part. When the inlet is viewed from the exterior of the airflow pipe in the front-rear direction, the connecting plate may be hidden by the grille part.

[0006] A blower attachment may be connected to a prime mover for use. The blower attachment may comprise: a prime mover; a shaft configured to be rotated by the prime mover; a fan coupled to the shaft; an airflow pipe in which the fan is housed; an inlet disposed at one end of the airflow pipe; an outlet disposed at another end of the airflow pipe; a shaft housing located inside the airflow pipe in proximity to the inlet and rotatably supporting the shaft; a connecting plate connecting an outer surface of the shaft housing and an inner surface of the airflow pipe; and an inlet cover attached to the inlet. The inlet cover may comprise a grille part defining an air hole through which air flows into the inlet. A direction from an exterior toward an interior of the airflow pipe through the inlet may be defined as a front direction. A direction from the interior toward the exterior of the airflow pipe through the inlet may be defined as a rear direction. The connecting plate may extend in a front-rear direction. A rear end of the connecting plate may face a front end of the grille part. When the inlet is viewed from the exterior of the airflow pipe in the front-rear direction, the connecting plate may be hidden by the grille part.BRIEF DESCRIPTION OF DRAWINGS

[0007] FIG. 1 illustrates a blower 2 according to an embodiment from a front upper right side.

[0008] FIG. 2 illustrates the blower 2 according to the embodiment with an attachment part 6 detached from a body part 4.

[0009] FIG. 3 illustrates the body part 4 of the blower 2 according to the embodiment in a cross section perpendicular to a left-right direction.

[0010] FIG. 4 illustrates the attachment part 6 in the blower 2 according to the embodiment in the cross section perpendicular to the left-right direction.

[0011] FIG. 5 illustrates a rear portion of a rear case 64 in the blower 2 according to the embodiment from a rear upper left side.

[0012] FIG. 6 illustrates a rear portion of the attachment part 6 in the blower 2 according to the embodiment from the rear upper left side.

[0013] FIG. 7 illustrates an inlet cover 76 of the blower 2 according to the embodiment from a front lower left side.

[0014] FIG. 8 illustrates a hole boss 132 and a stopper piece 174 and their surroundings in the blower 2 according to the embodiment from the front lower left side.

[0015] FIG. 9 illustrates the attachment part 6 in the blower 2 according to the embodiment from the rear side.

[0016] FIG. 10 illustrates a cross-sectional view along a line X-X in FIG. 9DETAILED DESCRIPTION

[0017] In one aspect of the present teachings, a blower may comprise: a prime mover; a shaft configured to be rotated by the prime mover; a fan coupled to the shaft; an airflow pipe in which the fan is housed; an inlet disposed at one end of the airflow pipe; an outlet disposed at another end of the airflow pipe; a shaft housing located inside the airflow pipe in proximity to the inlet and rotatably supporting the shaft; a connecting plate connecting an outer surface of the shaft housing and an inner surface of the airflow pipe; and an inlet cover attached to the inlet. The inlet cover may comprise a grille part defining an air hole through which air flows into the inlet. A direction from an exterior toward an interior of the airflow pipe through the inlet may be defined as a front direction. A direction from the interior toward the exterior of the airflow pipe through the inlet may be defined as a rear direction. The connecting plate may extend in a front-rear direction. A rear end of the connecting plate may face a front end of the grille part. When the inlet is viewed from the exterior of the airflow pipe in the front-rear direction, the connecting plate may be hidden by the grille part.

[0018] According to the above configuration, when the inlet is viewed from the upstream side in an airflow direction (i.e., from the rear side), the connecting plate is hidden by the grille part. Due to this, the air having flowed into the airflow pipe can be suppressed from being blown onto the rear end of the connecting plate. As a result of this, wind noise can be suppressed from being generated at the rear end of the connecting plate, by which noise accompanying with the wind of the blower can be mitigated.

[0019] In one aspect of the present teachings, a thickness of the rear end of the connecting plate may be less than or equal to a thickness of the front end of the grille part.

[0020] When the thickness of the rear end of the connecting plate (i.e., upstream end of the connecting plate) is greater than the thickness of the front end of the grille part (i.e., downstream end of the grille part), the air having passed near the grille part would be blown onto the rear end of the connecting plate. As a result of this, wind noise could be generated at the rear end of the connecting plate, and noise accompanying the airflow from the blower could be louder. According to the above configuration, because the thickness of the rear end of the connecting plate is equal to or less than the thickness of the front end of the grille part, the air having passed near the grille part flows without being blowing onto the rear end of the connecting plate. Due to this, wind noise can be suppressed from being generated at the rear end of the connecting plate, as a result of which noise accompanying the airflow from the blower can be mitigated.

[0021] In one aspect of the present teachings, in the front-rear direction, a distance between the rear end of the connecting plate and the front end of the grille part may be less than or equal to 1.0 mm.

[0022] When the distance between the rear end of the connecting plate (i.e., the upstream end of the connecting plate) and the front end of the grille part (i.e., the downstream end of the grille part) exceeds 1.0 mm, the air flowing along the surface of the grille part would be blown onto the rear end of the connecting plate after leaving the grille part from the front end of the grille part. As a result, wind noise could be generated at the rear end of the connecting plate, as a result of which noise accompanying the airflow from the blower could be louder. According to the above configuration, because the distance between the front end of the grille part and the rear end of the connecting plate is less than or equal to 1.0 mm, it is unlikely that the air flowing along the surface of the grille part is blown onto the rear end of the connecting plate after leaving the grille part from the front end of the grille part. Due to this, wind noise can be suppressed from being generated at the rear end of the connecting plate, by which noise accompanying the airflow from the blower can be mitigated.

[0023] In one aspect of the present teachings, the inlet cover may further comprise: a stopper part configured to engage with the shaft housing to stop the inlet cover from moving relative to the shaft housing in a circumferential direction of the airflow pipe; and a fastening part in which a fastener configured to fasten the inlet cover to the shaft housing is disposed. In a radial direction of the airflow pipe, each of the stopper part and the fastening part may be located inward in the radial direction of the grille part.

[0024] According to the above configuration, elements for fixing the position of the inlet cover relative to the shaft housing (i.e., the stopper part and the fastening part) are concentrated in proximity to the central axis of the airflow pipe. Due to this, the size of the shaft housing in the radial direction of the airflow pipe can be minimized.

[0025] In one aspect of the present teachings, the inlet cover may further comprise: a wall surface entered inside the airflow pipe to face the inner surface of the airflow pipe; and a rib protruding from the wall surface outward in a radial direction of the airflow pipe.

[0026] Because the material of the inlet cover may degrade due to aging, the inlet cover may be warped outward in the radial direction of the airflow pipe. According to the above configuration, if the inlet cover is deformed and warped outward in the radial direction of the airflow pipe, the rib would abut the inner surface of the airflow pipe. Due to this, the inlet cover can be suppressed from being deformed to be warped outward in the radial direction of the airflow pipe any further.

[0027] In one aspect of the present teachings, the blower may further comprise: a manipulation rod extending in the front-rear direction; and a rear housing disposed at a rear portion of the manipulation rod and in which the prime mover is housed. The airflow pipe may be attached to a front portion of the manipulation rod.

[0028] According to the above configuration, the user can manipulate the blower via the manipulation rod. Due to this, ease of operation of the blower can be improved.

[0029] In one aspect of the present teachings, a blower attachment may be connected to a prime mover for use. The blower attachment may comprise: a prime mover; a shaft configured to be rotated by the prime mover; a fan coupled to the shaft; an airflow pipe in which the fan is housed; an inlet disposed at one end of the airflow pipe; an outlet disposed at another end of the airflow pipe; a shaft housing located inside the airflow pipe in proximity to the inlet and rotatably supporting the shaft; a connecting plate connecting an outer surface of the shaft housing and an inner surface of the airflow pipe; and an inlet cover attached to the inlet. The inlet cover may comprise a grille part defining an air hole through which air flows into the inlet. A direction from an exterior toward an interior of the airflow pipe through the inlet may be defined as a front direction. A direction from the interior toward the exterior of the airflow pipe through the inlet may be defined as a rear direction. The connecting plate may extend in a front-rear direction. A rear end of the connecting plate may face a front end of the grille part. When the inlet is viewed from the exterior of the airflow pipe in the front-rear direction, the connecting plate may be hidden by the grille part.

[0030] According to the above configuration, when the inlet is seen from the upstream side in the air flow direction (i.e., from the rear side), the connecting plate is hidden by the grille part. Due to this, the air having flowed into the airflow pipe can be suppressed from being blown onto the rear end of the connecting plate. Due to this, wind noise can be suppressed from being generated at the rear end of the connecting plate, by which noise accompanying the airflow from the blower attachment can be mitigated.

[0031] Representative, non-limiting examples of the present disclosure will now be described in further detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the disclosure. Furthermore, each of the additional features and teachings disclosed below may be utilized separately or in conjunction with other features and teachings to provide improved blowers and blower attachments, as well as methods for using and manufacturing the same.

[0032] Moreover, combinations of features and steps disclosed in the following detailed description may not be necessary to practice the disclosure in the broadest sense, and are instead taught merely to particularly describe representative examples of the disclosure. Furthermore, various features of the above-described and below-described representative examples, as well as the various independent and dependent claims, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

[0033] All features disclosed in the description and / or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and / or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.EMBODIMENT

[0034] As illustrated in FIGS. 1, 2, a blower 2 comprises a body part 4 and an attachment part 6. The attachment part 6 is detachably attached to the body part 4. The attachment part 6 is a blower attachment configured to be used by being coupled to a prime mover (in the present embodiment, electric motor 36 illustrated in FIG. 3). The body part 4 is configured capable of receiving an attachment part that is different from the attachment part 6 (e.g., grass cutter attachment part). Accordingly, the body part 4 can be implemented for a working machine of a different type from the blower 2 (e.g., for grass cutter).

[0035] The body part 4 comprises a manipulation rod 8, a loop handle 10, a lock unit 12, a grip unit 14, and a rear housing 16. The manipulation rod 8 has a hollow pipe shape and extends linearly. In the present embodiment, a direction which is parallel to the longitudinal direction of the manipulation rod 8 and is oriented from the body part 4 toward the attachment part 6 will be defined as a front direction while a direction which is parallel to the longitudinal direction of the manipulation rod 8 and is oriented from the attachment part 6 toward the body part 4 will be defined as a rear direction. Likewise, a direction perpendicular to the front-rear directions and along which a trigger 32 to be described later is pushed in will be defined as an upward direction while a direction opposite therefrom will be defined as a downward direction. Likewise, a direction perpendicular to the front and rear directions and the upward and downward directions and to which the tip of an auxiliary grip 34 to be described later points will be defined as a left direction while an opposite direction therefrom will be defined as a right direction.

[0036] The lock unit 12 is disposed at a front portion of the manipulation rod 8. The lock unit 12 comprises a coupling tube 18, a lock lever 20, and an unlock button 22. The coupling tube 18 is fixed to the front portion of the manipulation rod 8. The coupling tube 18 has a tube shape having an opening frontward. The coupling tube 18 is configured to have a rear portion of a coupling rod 66 of the attachment part 6 inserted therethrough. The lock lever 20 is pivotably attached to the coupling tube 18. The unlock button 22 is disposed on the upper surface of the coupling tube 18. As illustrated in FIG. 1, the lock lever 20 is laid over the manipulation rod 8 substantially parallel thereto, and in a state where the unlock button 22 is not pushed in, the coupling rod 66 is fixed to the coupling tube 18. That is, the coupling rod 66 is prohibited from being removed from the coupling tube 18. When from this state the lock lever 20 is lifted substantially perpendicular to the manipulation rod 8 and the unlock button 22 is pushed in, the coupling rod 66 is allowed to be removed from the coupling tube 18. As illustrated in FIG. 2, by removing the coupling rod 66 from the coupling tube 18, the attachment part 6 can be detached from the manipulation rod 8. Also, by inserting the coupling rod 66 into the coupling tube 18 with the lock lever 20 lifted substantially perpendicular to the manipulation rod 8 and then laying down the lock lever 20 to be substantially parallel to the manipulation rod 8, the attachment part 6 can be attached to the manipulation rod 8 (see FIG. 1). As such, the attachment part 6 is detached from / attached to the manipulation rod 8 via the lock unit 12.

[0037] The grip unit 14 is disposed at the rear portion of the manipulation rod 8. The grip unit 14 comprises a grip housing 24. The grip housing 24 is constituted of a resin material shaped in a shape covering an outer peripheral surface of the manipulation rod 8. The manipulation rod 8 extends through the grip housing 24. A lever 26 is disposed on the upper surface of the grip housing 24. On the upper surface of the grip housing 24, an operation part 28 and an indicator 30 are disposed frontward of the lever 26. The indicator 30 is configured to indicate, for example, the operation state of the blower 2. In the operation part 28, a power switch for switching ON / OFF of the main power of the blower 2 for example is arranged. The trigger 32 is disposed below the grip housing 24. The trigger 32 is a member configured to switch operation / stop of the electric motor 36 (see FIG. 3). In a state where the lever 26 is not pushed in by a user, a user’s operation of pushing in the trigger 32 is prohibited. Contrary to this, when the lever 26 is pushed in by the user, the user’s operation of pushing in the trigger 32 is enabled. The user can activate the electric motor 36 (see FIG. 3) by pushing the lever 26 in with his / her palm grasping the grip housing 24, and pushing the trigger 32 in with the finger(s) of the same hand.

[0038] In the manipulation rod 8, the loop handle 10 for the user to grasp is disposed between the lock unit 12 and the grip unit 14. The loop handle 10 has a hollow pipe shape, and is shaped in a loop that is upwardly convex and also extending to lateral sides of the manipulation rod 8. Further, the auxiliary grip 34 which extends to a front left side is fixed to the left lower portion of the loop handle 10 . The user can carry the blower 2 around by grasping the grip housing 24 with one hand (e.g., right hand) and grasping the loop handle 10 or the auxiliary grip 34 with the other hand (e.g., left hand).

[0039] As illustrated in FIG. 3, a control board 38 configured to control operation of the electric motor 36 and the electric motor 36 is accommodated in the rear housing 16. A battery pack B is detachably attached to the rear portion of the rear housing 16. The control board 38 controls operation of the electric motor 36 by controlling electric power supplied from the battery pack B to the electric motor 36. The electric motor 36 is a brushless motor of inner rotor type comprising a motor shaft 40, a rotor 42 fixed to the motor shaft 40, and a stator 44 disposed outward of the rotor 42 in the radial direction. The motor shaft 40 is coupled to the rear portion of a first transmission shaft 48 extending inside the manipulation rod 8 via a reduction drive 46 accommodated in the rear housing16. The manipulation rod 8 rotatably supports the first transmission shaft 48.

[0040] As illustrated in FIG. 4, the attachment part 6 comprises a front case 62, the rear case 64, the coupling rod 66, a second transmission shaft 68, a third transmission shaft 70, a fan 72, a flow-straightening member 74, and the inlet cover 76. As illustrated in FIG. 1, the front case 62 and the rear case 64 are fixed to each other by first screws 78. As illustrated in FIG. 4, an airflow pipe 80 configured to have air flow therethrough is defined by the front case 62 and the rear case 64. The rear end of the rear case 64 comprises an inlet 82 into which air flows from the exterior to the interior of the airflow pipe 80. The front end of the front case 62 comprises an outlet 84 out of which air flows from the interior to the exterior of the airflow pipe 80. A central axis CX of the airflow pipe 80 extends along the front-rear direction.

[0041] The front case 62 comprises a case body 92 and an end pipe 94 configured to move relative to the case body 92 in the front-rear direction. The end pipe 94 is disposed at the front end of the front case 62 and comprises the outlet 84. The length of the airflow pipe 80 can be adjusted by moving the end pipe 94 relative to the case body 92.

[0042] The rear case 64 comprises a pipe body 102, a shaft housing 104, and eight connecting plates 106 (some of them are not illustrated). The pipe body 102, the shaft housing 104, and the eight connecting plates 106 are seamlessly integrated with each other. The pipe body 102 defines the airflow pipe 80 together with the front case 62. The shaft housing 104 rotatably supports the third transmission shaft 70. The eight connecting plates 106 connect the inner surface of the pipe body 102 and the outer surface of the shaft housing 104. The shaft housing 104 comprises an outer shell part 108 connected to the eight connecting plates 106, a shaft support part 110 supporting the third transmission shaft 70, a clamp pipe 112 through which the coupling rod 66 is inserted, and three screw bosses 114 (some of them are not illustrated) to which the inlet cover 76 is fastened . The shaft support part 110 rotatably supports the third transmission shaft 70 via bearings 111a, 111b.

[0043] As illustrated in FIG. 5, the outer surface of the outer shell part 108 is shaped in a dome extending outward in the radial direction of the central axis CX from rear to front. The eight connecting plates 106 extend so as to be perpendicular to each of the inner surface of the pipe body 102 and the outer surface of the outer shell part 108. The eight connecting plates 106 are disposed at equal intervals along the circumferential direction of the central axis CX. A 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 part 108, then bends frontward, and extends to the inner surface of the pipe body 102.

[0044] The clamp pipe 112 comprises a pipe body 120 having a slit 118 and stopper pieces 122 below the pipe body 120 on opposing sides of the slit 118. The pipe body 120 has an opening on the rear side. The pipe body 120 has the front portion of the coupling rod 66 (see FIG. 4) inserted therethrough. The pipe body 120 comprises a screw hole 124. The coupling rod 66 has a through hole (not illustrated) at a position corresponding to the screw hole 124. A second screw 126 (see FIG. 6) is screwed into the screw hole 124. With the second screw 126 screwed into the screw hole 124, the tip of the second screw 126 having passed the screw hole 124 is inserted into the through hole of the coupling rod 66. Due to this, it can be suppressed that the position of the coupling rod 66 relative to the clamp pipe 112 is displaced in the front-rear direction and that the coupling rod 66 rotates relative to the clamp pipe 112. Further, the stopper piece 122 on the left has a through hole 128. The stopper piece 122 on the right comprises a screw hole 129 (see FIG. 4) at a position opposed to the through hole 128 of the left stopper piece 122. A third screw 130 (see FIG. 6) having passed the through hole 128 is screwed into the screw hole 129. With the third screw 130 passed through the through hole 128 and screwed into the screw hole 129, the stopper pieces 122 approach each other, by which the width of the slit 118 shrinks, and the inner diameter of the pipe body 120 shrinks. Due to this, the coupling rod 66 is clamped against the inner surface of the clamp pipe 112.

[0045] The three screw bosses 114 are disposed outward of the pipe body 120 of the clamp pipe 112 in the radial direction and disposed inward of the rear end of the outer shell part 108 in the radial direction. The three screw bosses 114 are disposed such that the first one is above the clamp pipe 112, the second one is to the left of the left stopper piece 122, and the third one is to the right of the right stopper piece 122. The three screw bosses 114 are arranged at equal intervals along the circumferential direction of the central axis CX.

[0046] As illustrated in FIG. 4, the coupling rod 66 has a hollow pipe shape and extends linearly. The coupling rod 66 rotatably supports the second transmission shaft 68. The second transmission shaft 68 extends in the front-rear direction so that it extends inside the coupling rod 66 . The rear portion of the second transmission shaft 68 is coupled to the front portion of the first transmission shaft 48 (see FIG. 3) extending inside the manipulation rod 8 (see FIG. 3). The front portion of the second transmission shaft 68 extends into an internal space of the shaft support part 110 to be coupled to the rear portion of the third transmission shaft 70. The front portion of the third transmission shaft 70 protrudes frontward from the shaft housing 104.

[0047] The fan 72 is disposed frontward of the shaft housing 104. The fan 72 comprises a hub 142 coupled to the front portion of the third transmission shaft 70 and a plurality of movable vanes 144 protruding from the outer surface of the hub 142. The hub 142 and the plurality of movable vanes 144 are seamlessly integrated with each other. The outer surface of the hub 142 has a circular cylinder shape. The outer surface of the hub 142 is flush with the outer surface in proximity to the front end of the outer shell part 108 of the shaft housing 104. When the electric motor 36 (see FIG. 3) is driven, the motor shaft 40 (see FIG. 3) rotates. The rotation of the motor shaft 40 is transmitted to the fan 72 via the reduction drive 46 (see FIG. 3), the first transmission shaft 48 (see FIG. 3), the second transmission shaft 68, and the third transmission shaft 70. Due to this, the fan 72 rotates. When the fan 72 rotates, airflow traveling from the inlet 82 to the outlet 84 (i.e., airflow from rear to front) is generated inside the airflow pipe 80. Due to this, air outside the airflow pipe 80 is suctioned through the inlet 82 into the airflow pipe 80 and air inside the airflow pipe 80 is discharged through the outlet 84 to the exterior of the airflow pipe 80.

[0048] The flow-straightening member 74 is disposed frontward of the fan 72. The flow-straightening member 74 comprises an outer frame 146, a cone 148, and a plurality of guide (stationary) vanes 150. The outer frame 146, the cone 148, and the plurality of guide vanes 150 are seamlessly integrated with each other. The outer frame 146 is fixed to each of the front case 62 and the rear case 64 under a state of being in contact with a step part 64a defined 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 body 102. The central axis of the cone 148 coincides with the central axis CX of the airflow pipe 80. The cone 148 comprises a circular pipe part 152 at which the plurality of guide vanes 150 is arranged and a diameter-decreasing part 154 extending frontward from the front end of the circular pipe part 152. The outer surface of the circular pipe part 152 is flush with the outer surface of the hub 142. The diameter-decreasing part 154 has its diameter decreasing as it extends frontward. The plurality of guide vanes 150 connects the inner surface of the outer frame 146 and the outer surface of the cone 148.

[0049] As illustrated in FIG. 7, the inlet cover 76 comprises a cup part 162, a flange part 164, a first circumferential wall part 165, a grille part 166, a second circumferential wall part 168, an outer peripheral part 170, and leg parts 172. The cup part 162, the flange part 164, the first circumferential wall part 165, the grille part 166, the second circumferential wall part 168, the outer peripheral part 170, and the leg parts 172 are seamlessly integrated with each other . The cup part 162 has a shape conforming to the rear end and the outer circumference of the clamp pipe 112 (see FIG. 5). The cup part 162 covers the rear end and the outer circumference of the clamp pipe 112. The flange part 164 is connected to the front end of the cup part 162, and spans in the radial direction of the central axis CX. The flange part 164 covers the rear sides of the three screw bosses 114 (see FIG. 5). The front surface of the flange part 164 comprises three hole bosses 132 and three stopper pieces 174. The three hole bosses 132 and the three stopper pieces 174 are arranged at positions corresponding to the three screw bosses 114 (see FIG. 5) of the shaft housing 104. The three hole bosses 132 are adjacent to the first circumferential wall part 165. The first circumferential wall part 165 extends frontward from the outer peripheral rim of the flange part 164.

[0050] As illustrated in FIG. 6, a fourth screw 134 is disposed in each of the three hole bosses 132. Each fourth screw 134 is screwed into the screw hole 114a (see FIG. 5) of the corresponding screw boss 114 while passing through a through hole 132a of the corresponding hole boss 132 (see FIG. 7). Due to this, the inlet cover 76 is fastened to the shaft housing 104.

[0051] As illustrated in FIG. 8, each of the stopper pieces 174 has a semicylindrical shape as if a half of the cylinder is removed. Each stopper piece 174 extends to a spot frontward of the front surface of the hole boss 132. Each stopper piece 174 is disposed so as to intervene between the central axis CX (see FIG. 7) and the central axis of the corresponding through hole 132a. The outer peripheral surface of each stopper piece 174 is directed inward in the radial direction of the central axis CX. The inner peripheral surface of each stopper piece 174 is directed outward in the radial direction of the central axis CX. The inner peripheral surface of each stopper piece 174 has a shape conforming to the outer peripheral surface of the corresponding screw boss 114 (see FIG. 5) of the shaft housing 104. By the inner peripheral surface of each stopper piece 174 fitting into the outer peripheral surface of the corresponding screw boss 114 (i.e., by each stopper piece 174 being engaged with the corresponding screw boss 114), the inlet cover 76 is restricted from moving relative to the shaft housing 104 in the circumferential direction of the central axis CX. The inner peripheral surface of the stopper piece 174 further comprises crushable ribs 176 extending in the front-rear direction. The crush ribs 176 contact the outer peripheral surface of each screw boss 114 to suppress play between each pair of the stopper piece 174 and the screw boss 114.

[0052] As illustrated in FIG. 9, the grille part 166 is disposed outward of the first circumferential wall part 165 in the radial direction of the central axis CX. The grille part 166 comprises eight radial grilles 178 extending in the radial direction of the central axis CX and three circumferential grilles 180 extending in the circumferential direction of the central axis CX . The eight radial grilles 178 connect the outer peripheral surface of the first circumferential wall part 165 and the inner peripheral surface of the second circumferential wall part 168. The three circumferential grilles 180 intersect each of the eight radial grilles 178. The grille part 166 prevents user’s hand(s) from entering the interior of the airflow pipe 80. An air hole 182 extending through the inlet cover 76 in the front-rear direction is defined among the grille part 166.

[0053] As illustrated in FIG. 6, the eight radial grilles 178 are disposed so that each radial grille 178 is aligned with corresponding one of the eight connecting plates 106 along the front-rear direction. Accordingly, the eight radial grilles 178 are disposed at equal intervals in the circumferential direction of the central axis CX. A front end surface 178a of each radial grille 178 has a shape conforming to the rear end surface 106a of the corresponding one of the connecting plates 106. Specifically, the front end surface 178a of each radial grille 178 extends from the outer peripheral surface of the first circumferential wall part 165 parallel to the radial direction of the central axis CX, then bends frontward, and extends to the inner peripheral surface of the second circumferential wall part 168.

[0054] As illustrated in FIG. 10, the front end surface 178a of each radial grilles 178 faces the rear end surface 106a of the corresponding connecting plate 106. The distance in the front-rear direction between the front end surface 178a of each radial grille 178 and the rear end surface 106a of the corresponding connecting plate 106 is within a range from 0.0 mm to 1.0 mm, and in the present embodiment, it is 0.6 mm. This value is based on measurement results of noise generated in proximity to the inlet cover 76 when the blower 2 operates. The measurements were conducted by changing the distance between the front end surfaces 178a and the rear end surfaces 106a, and the results showed that the noise decreased remarkably when the distance between the front end surfaces 178a and the rear end surfaces 106a is less than or equal to 1.0 mm and also that the noise decreased more remarkably when the distance between the front end surfaces 178a and the rear end surfaces 106a is less than or equal to 0.6 mm. Further, each of the radial grilles 178 comprises a thickness increasing portion 184 the thickness of which increases from rear to front, and a first constant thickness portion 186 having a substantially constant thickness. The front end of the thickness increasing portion 184 is connected to the rear end of the first constant thickness portion 186. The front end surface 178a of each radial grille 178 is arranged 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 within a range from 2.0 mm to 2.4 mm, and in the present embodiment it is 2.2 mm. Also, each of the connecting plates 106 comprises a second constant thickness portion 188 having a substantially constant thickness and a thickness decreasing portion 190 the thickness of which decreases from rear to front. The front end of the second constant thickness portion 188 is connected to the rear end of the thickness decreasing portion 190 . The rear end surface 106a of each connecting plate 106 is arranged at the rear end of the second constant thickness portion 188. The thickness of the second constant thickness portion 188 (i.e., thickness of the rear end surface 106a) is within a range from 1.4 mm to 2.0 mm, and in the present embodiment, it is 1.7mm. The thickness of the second constant thickness portion 188 (i.e., thickness of the rear end surface 106a) is less than or equal to the thickness of the first constant thickness portion 186 (i.e., thickness of the front end surface 178a).

[0055] As illustrated in FIG. 9, when the inlet 82 is seen from the rear side, the eight connecting plates 106 are hidden by the eight radial grilles 178, respectively. Due to this, air flowing from the exterior to the interior of the airflow pipe 80 via the inlet 82 (i.e., air flowing from rear toward front) is not blown onto the rear end surfaces 106a (see FIG. 5) of the connecting plates 106. Due to this, wind noise can be suppressed from being generated at the rear end surfaces 106a of the connecting plates 106, and also the flow of air can be suppressed from being inhibited by the rear end surfaces 106a of the connecting plates 106.

[0056] As illustrated in FIG. 5, a diameter expanding portion 192 the diameter of which expands from front to rear is disposed at or in proximity to the rear end of the pipe body 102 of the rear case 64. As illustrated in FIG. 6, the inlet cover 76 is attached to the shaft housing 104 with the front surface of the outer peripheral part 170 abutting the rear end of the diameter expanding portion 192. The leg parts 172 protrude downward from the outer surface of the outer peripheral part 170. The user can place the blower 2 on a resting surface such as a ground, by allowing the leg parts 172 of the inlet cover 76 and a leg part 194 (see FIG. 1) disposed on the lower surface of the rear housing 16 to be in contact with the resting surface.

[0057] As illustrated in FIG. 7, the second circumferential wall part 168 comprises a plurality of anti-warp ribs 196 protruding from the outer peripheral surface of the second circumferential wall part 168. The plurality of anti-warp ribs 196 extends in the front-rear direction. The outer peripheral surface of the second circumferential wall part 168 enters inside the diameter expanding portion 192 (see FIG. 5) of the rear case 64, and faces the inner surface of the diameter expanding portion 192. The plurality of anti-warp ribs 196 is arranged at positions facing anti-warp pieces 198 (see FIG. 5) disposed on the inner surface of the diameter expanding portion 192 of the rear case 64. If the inlet cover 76 deforms and warps outward in the radial direction of the airflow pipe 80, the anti-warp ribs 196 abut the anti-warp pieces 198. Due to this, the inlet cover 76 is suppressed from deforming to be warped outward in the radial direction of the airflow pipe 80 any further.Modifications

[0058] (See FIG. 1) The blower 2 may not comprise the manipulation rod 8. That is, the blower 2 may be composed of the body part 4 and the attachment part 6 that are permanently integrated with each other (i.e., cannot be detached from each other). In this case, the electric motor 36 may be disposed inside the airflow pipe 80 (e.g., inside the shaft housing 104). The attachment part 6 may not comprise the coupling rod 66 and the second transmission shaft 68. The inlet cover 76 may not have a shape for preventing interference with the coupling rod 66. Alternatively, a portion of the blower 2 may be configured to be worn on the back of the user.

[0059] (See FIG. 1) The blower 2 may be configured to be powered by a power supply other than the battery pack B. For example, the blower 2 may comprise a cable and a plug for connecting with an external power supply, and be configured to be powered by the external power supply.

[0060] (See FIG. 3) The blower 2 may comprise a prime mover other than the electric motor 36 (e.g., may comprise an engine). Further, the electric motor 36 may be a motor of another type than the brushless motor of inner rotor (e.g., may be a brushless motor of outer rotor).

[0061] (See FIG. 4) The airflow pipe 80 may not extend linearly, but may be curved. As a result, the air flow direction at the inlet 82 and the air flow direction at the outlet 84 may differ from each other.

[0062] (See FIGS. 5 and 7) The connecting plates 106 may not extend parallel to the radial direction of the central axis CX. For example, the connecting plates 106 may be curved in the circumferential direction as they extend outward in the radial direction of the central axis CX. In this case, the radial grilles 178 may also be curved in the circumferential direction as they extend outward in the radial direction of the central axis CX. As a result, when the inlet 82 is seen from the rear side, the connecting plates 106 may be hidden by the radial grilles 178.

[0063] (See FIG. 10) The distance in the front-rear direction between the front end surfaces 178a of the radial grilles 178 and the rear end surfaces 106a of the connecting plates 106 may exceed 1.0 mm.

[0064] (See FIGS. 5, 7, and FIG. 8) The stopper pieces 174 and the hole bosses 132 may be disposed radially outward of the radial grilles 178. For example, the stopper pieces 174 and the hole bosses 132 may be disposed on the outer peripheral part 170. In this case, the screw bosses 114 may be arranged at the rear end of the pipe body 102 so as to face the hole bosses 132. Also, the stopper pieces 174 may be disposed outward relative to the screw bosses 114 in the radial direction of the central axis CX. Also, each of the stopper pieces 174 may extend along the entire circumference of the corresponding hole boss 132.

[0065] (See FIG. 7) The second circumferential wall part 168 of the inlet cover 76 may not comprise the anti-warp ribs 196. That is, the outer peripheral surface of the second circumferential wall part 168 may be a smooth cylindrical surface.Features of Embodiments

[0066] In one or more embodiments, the blower 2 comprises: the electric motor 36 (example of a prime mover); the third transmission shaft 70 (example of a shaft) configured to be rotated by the electric motor 36; the fan 72 coupled to the third transmission shaft 70; the airflow pipe 80 in which the fan 72 is housed; the inlet 82 disposed at one end of the airflow pipe 80; the outlet 84 disposed at another end of the airflow pipe 80; the shaft housing 104 located inside the airflow pipe 80 in proximity to the inlet 82 and rotatably supporting the third transmission shaft 70; the connecting plates 106 connecting the outer surface of the shaft housing 104 and the inner surface of the airflow pipe 80; and the inlet cover 76 attached to the inlet 82. The inlet cover 76 comprises the radial grilles 178 (example of a grille part) defining the air hole 182 through which air flows into the inlet 82. The direction from the exterior toward the interior of the airflow pipe 80 through the inlet 82 is defined as the front direction, the direction from the interior toward the exterior of the airflow pipe 80 through the inlet 82 is defined as the rear direction, and the connecting plates 106 extend in the front-rear direction. The rear end surfaces 106a of the connecting plates 106 face the front end surfaces 178a of the radial grilles 178. When the inlet 82 is viewed from the rear side, the connecting plates 106 are hidden by the radial grilles 178.

[0067] According to the above configuration, when the inlet 82 is viewed from the upstream side in the airflow direction (i.e., rear side), the connecting plates 106 are hidden by the radial grilles 178. Due to this, the air having flowed into the airflow pipe 80 can be suppressed from being blown onto the rear end surfaces 106a of the connecting plates 106. As a result of this, wind noise can be suppressed from being generated at the rear end surfaces 106a of the connecting plates 106, by which noise accompanying with the wind of the blower 2 can be mitigated.

[0068] In one or more embodiments, the thickness of the rear end surface 106a of each of the connecting plates 106 is less than or equal to the thickness of the front end surface 178a of each radial grille 178.

[0069] When the thickness of the rear end surface 106a of each connecting plate 106 (i.e., upstream end of the connecting plate 106) is greater than the thickness of the front end surface 178a of each radial grille 178 (i.e., downstream end of the radial grille 178), the air having passed near the radial grilles 178 would be blown onto the rear end surfaces 106a of the connecting plates 106. As a result of this, wind noise could be generated at the rear end surfaces 106a of the connecting plates 106, and noise accompanying the airflow from the blower 2 could be louder. According to the above configuration, because the thickness of the rear end surface 106a of each connecting plate 106 is equal to or less than the thickness of the front end surface 178a of each radial grille 178, the air having passed near the radial grilles 178 flows without being blown onto the rear end surfaces 106a of the connecting plates 106. Due to this, wind noise can be suppressed from being generated at the rear end surfaces 106a of the connecting plate s 106, as a result of which noise accompanying the airflow from the blower 2 can be mitigated.

[0070] In one or more embodiments, in the front-rear direction, the distance between the rear end surface 106a of each connecting plate 106 and the front end surface 178a of the corresponding radial grille 178 is less than or equal to 1.0 mm.

[0071] When the distance between the rear end surface 106a of each connecting plate 106 (i.e., the upstream end of the connecting plate 106) and the front end surface 178a of the corresponding radial grille 178 (i.e., the downstream end of the radial grille 178) exceeds 1.0 mm, the air flowing along the surfaces of the radial grilles 178 is blown onto the rear end surfaces 106a of the connecting plates 106 after leaving the radial grilles 178 from the front end surfaces 178a of the radial grilles 178. As a result, wind noise could be generated at the rear end surfaces 106a of the connecting plates 106, as a result of which noise accompanying the airflow from the blower 2 could be louder. According to the above configuration, because the distance between the front end surfaces 178a of the radial grilles 178 and the rear end surfaces 106a of the connecting plates 106 is less than or equal to 1.0 mm, it is unlikely that the air flowing along the surfaces of the radial grilles 178 is blown onto the rear end surfaces 106a of the connecting plates 106 after leaving the radial grilles 178 from the front end surfaces 178a of the radial grilles 178. Due to this, wind noise can be suppressed from being generated at the rear end surfaces 106a of the connecting plates 106, by which noise accompanying the airflow from the blower 2 can be mitigated.

[0072] In one or more embodiments, the inlet cover 76 further comprises: the stopper pieces 174 (example of a stopper part) configured to engage with the shaft housing 104 to stop the inlet cover 76 from moving relative to the shaft housing 104 in the circumferential direction of the airflow pipe 80; and the hole bosses 132 (example of a fastening part) in which the fourth screws 134 (example of a fastener) configured to fasten the inlet cover 76 to the shaft housing 104 are disposed. In the radial direction of the airflow pipe 80, each of the stopper pieces 174 and the hole bosses 132 are located inward in the radial direction of the radial grilles 178.

[0073] According to the above configuration, elements for fixing the position of the inlet cover 76 to the shaft housing 104 (i.e., the stopper pieces 174 and the hole bosses 132) are concentrated in proximity to the central axis CX of the airflow pipe 80. Due to this, the size of the shaft housing 104 in the radial direction of the airflow pipe 80 can be minimized.

[0074] In one or more embodiments, the inlet cover 76 further comprises: the outer peripheral surface of the second circumferential wall part 168 (example of a wall surface) entered inside the airflow pipe 80 to face the inner surface of the airflow pipe 80; and the anti-warp ribs 196 (example of a rib) protruding from the outer peripheral surface of the second circumferential wall part 168 outward in the radial direction of the airflow pipe 80.

[0075] Because the material of the inlet cover 76 may degrade due to aging, the inlet cover 76 may be warped outward in the radial direction of the airflow pipe 80. According to the above configuration, if the inlet cover 76 is deformed and warped outward in the radial direction of the airflow pipe 80, the anti-warp ribs 196 would abut the inner surface of the airflow pipe 80. Due to this, the inlet cover 76 can be suppressed from being deformed to be warped outward in the radial direction of the airflow pipe 80 any further.

[0076] In one or more embodiments, the blower 2 further comprises: the manipulation rod 8 extending in the front-rear direction; and the rear housing 16 disposed at the rear portion of the manipulation rod 8 and in which the electric motor 36 is housed. The airflow pipe 80 is attached to the front portion of the manipulation rod 8.

[0077] According to the above configuration, the user can manipulate the blower 2 via the manipulation rod 8. Due to this, ease of operation of the blower 2 can be improved.

[0078] In one or more embodiments, the attachment part 6 (example of a blower attachment) is connected to the electric motor 36 for use. The attachment part 6 comprises: the third transmission shaft 70 configured to be rotated by the electric motor 36; the fan 72 coupled to the third transmission shaft 70; the airflow pipe 80 in which the fan 72 is housed; the inlet 82 disposed at one end of the airflow pipe 80; the outlet 84 disposed at another end of the airflow pipe 80; the shaft housing 104 located inside the airflow pipe 80 in proximity to the inlet 82 and rotatably supporting the third transmission shaft 70; the connecting plates 106 connecting the outer surface of the shaft housing 104 and the inner surface of the airflow pipe 80; and the inlet cover 76 attached to the inlet 82. The inlet cover 76 comprises the radial grilles 178 defining the air hole 182 through which air flows into the inlet 82. The direction from the exterior toward the interior of the airflow pipe 80 through the inlet 82 is defined as the front direction, the direction from the interior toward the exterior of the airflow pipe 80 through the inlet 82 is defined as the rear direction, and the connecting plates 106 extend in the front-rear direction. The rear end surfaces 106a of the connecting plates 106 face the front end surfaces 178a of the radial grilles 178. When the inlet 82 is viewed from the rear side, the connecting plates 106 are hidden by the radial grilles 178.

[0079] According to the above configuration, when the inlet 82 is seen from the upstream side in the air flow direction (i.e., rear side), the connecting plates 106 are hidden by the radial grilles 178. Due to this, the air having flowed into the airflow pipe 80 can be suppressed from being blown onto the rear end surfaces 106a of the connecting plates 106. Due to this, wind noise can be suppressed from being generated at the rear end surfaces 106a of the connecting plates 106, by which noise accompanying the airflow from the attachment part 6 can be mitigated.

Claims

1. A blower comprising:a prime mover;a shaft configured to be rotated by the prime mover;a fan coupled to the shaft;an airflow pipe in which the fan is housed;an inlet disposed at one end of the airflow pipe;an outlet disposed at another end of the airflow pipe;a shaft housing located inside the airflow pipe in proximity to the inlet and rotatably supporting the shaft;a connecting plate connecting an outer surface of the shaft housing and an inner surface of the airflow pipe; andan inlet cover attached to the inlet,whereinthe inlet cover comprises a grille part defining an air hole through which air flows into the inlet,a direction from an exterior toward an interior of the airflow pipe through the inlet is defined as a front direction,a direction from the interior toward the exterior of the airflow pipe through the inlet is defined as a rear direction,the connecting plate extends in a front-rear direction,a rear end of the connecting plate faces a front end of the grille part, andwhen the inlet is viewed from the exterior of the airflow pipe in the front-rear direction, the connecting plate is hidden by the grille part.

2. The blower according to claim 1, whereina thickness of the rear end of the connecting plate is less than or equal to a thickness of the front end of the grille part.

3. The blower according to claim 1, whereinin the front-rear direction, a distance between the rear end of the connecting plate and the front end of the grille part is less than or equal to 1.0 mm.

4. The blower according to claim 1, wherein the inlet cover further comprises:a stopper part configured to engage with the shaft housing to stop the inlet cover from moving relative to the shaft housing in a circumferential direction of the airflow pipe; anda fastening part in which a fastener configured to fasten the inlet cover to the shaft housing is disposed, andin a radial direction of the airflow pipe, each of the stopper part and the fastening part is located inward in the radial direction of the grille part.

5. The blower according to claim 1, whereinthe inlet cover further comprises:a wall surface entered inside the airflow pipe to face the inner surface of the airflow pipe; anda rib protruding from the wall surface outward in a radial direction of the airflow pipe.

6. The blower according to claim 1, further comprising:a manipulation rod extending in the front-rear direction; anda rear housing disposed at a rear portion of the manipulation rod and in which the prime mover is housed,wherein the airflow pipe is attached to a front portion of the manipulation rod.

7. A blower attachment for use connected to a prime mover, comprising:a shaft configured to be rotated by the prime mover;a fan coupled to the shaft;an airflow pipe in which the fan is housed;an inlet disposed at one end of the airflow pipe;an outlet disposed at another end of the airflow pipe;a shaft housing located inside the airflow pipe in proximity to the inlet and rotatably supporting the shaft;a connecting plate connecting an outer surface of the shaft housing and an inner surface of the airflow pipe; andan inlet cover attached to the inlet,whereinthe inlet cover comprises a grille part defining an air hole through which air flows into the inlet,a direction from an exterior toward an interior of the airflow pipe through the inlet is defined as a front direction,a direction from the interior toward the exterior of the airflow pipe through the inlet is defined as a rear direction,the connecting plate extends in a front-rear direction,a rear end of the connecting plate faces a front end of the grille part, andwhen the inlet is viewed from the exterior of the airflow pipe in the front-rear direction, the connecting plate is hidden by the grille part.

8. The blower according to claim 2, whereinin the front-rear direction, a distance between the rear end of the connecting plate and the front end of the grille part is less than or equal to 1.0 mm,the inlet cover further comprises:a stopper part configured to engage with the shaft housing to stop the inlet cover from moving relative to the shaft housing in a circumferential direction of the airflow pipe; anda fastening part in which a fastener configured to fasten the inlet cover to the shaft housing is disposed, andin a radial direction of the airflow pipe, each of the stopper part and the fastening part is located inward in the radial direction of the grille part,the inlet cover further comprises:a wall surface entered inside the airflow pipe to face the inner surface of the airflow pipe; anda rib protruding from the wall surface outward in the radial direction of the airflow pipe,the blower further comprises:a manipulation rod extending in the front-rear direction; anda rear housing disposed at a rear portion of the manipulation rod and in which the prime mover is housed,the airflow pipe is attached to a front portion of the manipulation rod.

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