JP7254636B2 - Blower - Google Patents

Description

The present disclosure relates to a blower, which is a type of work machine.

A blower, which is a type of working machine, is known. A blower is held or worn by a user in a predetermined posture, and blows air to collect scattered objects such as fallen leaves and cut grass. Hand-held blowers and backpack-type blowers are widely used as this type of blower.

Patent Literature 1 discloses a backpack type blower. The blower includes a volute case, an impeller rotatably supported in a volute chamber of the volute case, a motor connected to the impeller for driving the impeller, and an outer case housing the volute case and the motor.

JP 2016-204930 A

In the blower described above, since the motor is arranged in the outer case, the noise of the motor is suppressed from radiating to the surroundings. This specification provides a technique capable of further suppressing the emission of motor noise to the surroundings by making further improvements.

The technology disclosed herein is embodied in a blower that is held or worn by a user (eg, a handheld blower or a backpack blower). The blower includes a volute case defining a suction port, a volute chamber and a discharge port, an impeller rotatably supported in the volute chamber, a motor connected to the impeller and driving the impeller, a volute case and the motor. It is provided with an outer case for housing, and a sound absorbing member positioned between the volute case and the outer case and positioned on an extension line of the rotating shaft of the motor.

In the blower described above, the sound absorbing member is arranged on an extension of the rotating shaft of the motor. According to such a configuration, the noise of the motor is not only confined within the outer case, but also absorbed by the sound absorbing member. As a result, it is possible to effectively suppress the noise of the motor from radiating to the surroundings.

1 is a perspective view showing the appearance of a blower 10 of an embodiment; FIG. 2 is an exploded perspective view of the blower 10; FIG. 3 is a cross-sectional view showing the internal structure of the blower 10; FIG. Arrows F in the drawing schematically indicate the flow of air in the air path 42 . 3 is a diagram showing the internal structure of the blower 10 with a part of the outer case 14 removed; FIG. Arrows F in the drawing schematically indicate the flow of air in the air paths 42, 42a, 42b. FIG. 4 is a cross-sectional view of a volute case; FIG. 4 is an exploded perspective view of the volute case; FIG. 4 is an exploded perspective view of part of the blower 10 showing sound absorbing members 62 , 64 , 66 and 68 ;

In one embodiment of the present technology, the sound absorbing member is also located on an extension of the axis of rotation of the impeller. With such a configuration, impeller noise can also be effectively absorbed.

In an embodiment of the present technology, the sound absorbing member may face the inlet of the volute case. According to such a configuration, it is possible to effectively absorb wind noise generated from the volute case as well.

In one embodiment of the present technology, the sound absorbing member may be attached to the inner surface of the outer case. With such a configuration, it is easy to arrange the sound absorbing member at an appropriate position when manufacturing the blower.

In one embodiment of the present technology, the sound absorbing member may be composed of a sponge. The term "sponge" as used herein broadly means a spongy (or porous) material, and the material that constitutes it is not particularly limited. The sound absorbing member can be made of various materials such as resin material and rubber material.

In one embodiment of the present technology, the sound absorbing member may have a first sound absorbing member and a second sound absorbing member facing each other across the motor. With such a configuration, the noise of the motor can be effectively absorbed.

In one embodiment of the present technology, the blower may further include a cylindrical third sound absorbing member that surrounds the motor in a radial direction perpendicular to the rotation axis of the motor. With such a configuration, it is possible to further absorb the noise of the motor.

In one embodiment of the present technology, the volute case may have a discharge duct projecting outside the outer case. In this case, the outer case may have a duct opening through which the discharge duct passes. The blower may further include a fourth sound absorbing member provided in a gap between the duct opening and the discharge duct. According to such a configuration, it is possible to effectively suppress leakage of motor noise from the duct opening.

In the above-described embodiment, a relatively wide gap can be provided between the duct opening and the discharge duct by providing the fourth sound absorbing member. Therefore, the outer case may support the volute case via at least one vibration isolating member. According to such a configuration, it is possible to suppress transmission of vibrations of the volute case and the motor to the user.

In one embodiment of the present technology, the blower may be a backpack type blower worn on the back of the user. Alternatively, as another embodiment, the blower may be a handheld blower that has a grip for the user to grasp and is held in a predetermined position by the user.

Below, representative and non-limiting embodiments of the present invention will be described in detail with reference to the drawings. This detailed description is merely intended to provide those skilled in the art with details for implementing a preferred embodiment of the invention, and is not intended to limit the scope of the invention. Moreover, the additional features and inventions disclosed below can be used separately or in conjunction with other features and inventions to provide still improved blowers.

Moreover, any combination of features and steps disclosed in the following detailed description are not required to practice the invention in its broadest sense, but are specifically intended to illustrate representative embodiments of the invention only. It is described. Moreover, various features of the exemplary embodiments described above and below, as well as those set forth in the independent and dependent claims, are described herein in providing additional and useful embodiments of the invention. They do not have to be combined in the exact order given or in the order listed.

All features set forth in the specification and/or claims, apart from the configuration of the features set forth in the examples and/or claims, are limitations on the originally disclosed and claimed subject matter: They are intended to be disclosed separately and independently of each other. Moreover, all numerical ranges and groupings or populations are intended to disclose configurations intermediate therebetween as limitations on the original disclosure as well as the specific subject matter claimed.

A blower 10 of an embodiment will be described with reference to the drawings. The blower 10 of this embodiment is a backpack type blower, and is a type of working machine mainly used outdoors. The blower 10 is mounted on the user's back in a predetermined posture, and blows air to collect scattered objects such as fallen leaves and cut grass. The blower 10 is a work machine that uses the battery pack 2 as a power source, and is configured such that the two battery packs 2 are detachable. Note that the number of battery packs 2 is not limited to two.

As shown in FIGS. 1-4, the blower 10 includes a volute pump 12, an outer case 14 housing the volute pump 12, and a pair of shoulder straps 16. As shown in FIGS. A pair of shoulder straps 16 are fixed to the outer case 14 to secure the outer case 14 to the back of the user. The outer case 14 supports the volute pump 12 via a plurality of vibration isolation members 13 . The anti-vibration member 13 is an elastic member such as a spring or rubber. As an example, the outer case 14 in this embodiment is composed of a plurality of segments (parts) including a base member 14a and a cover member 14b. The cover member 14b is attached to the base member 14a, and the base member 14a and the cover member 14b face each other with the volute pump 12 interposed therebetween.

The outer case 14 is provided with two battery interfaces 18 . One battery pack 2 is detachably attached to each battery interface 18 . Each battery interface 18 is provided with a battery terminal 18a. The battery terminal 18 a electrically connects with the battery pack 2 attached to the battery interface 18 . The battery terminals 18a include a pair of power terminals and a plurality of communication terminals. Note that the number of battery interfaces 18 is not limited to two, and the blower 10 may have at least one battery interface 18 .

The blower 10 includes a discharge nozzle 20 connected to the volute pump 12 and an operating grip 22 provided on the discharge nozzle 20 . The operating grip 22 is provided with a plurality of switches, such as triggers 24, which are operated by the user. When the user operates the trigger 24 , power is supplied from one or two battery packs 2 to the volute pump 12 to start the volute pump 12 . Thereby, the blower 10 discharges air from the discharge nozzle 20 .

The volute pump 12 includes a volute case 26 , an impeller 28 located within the volute case 26 , and a motor 30 connected to the impeller 28 . The volute case 26 defines a suction port 26a, a volute chamber 26b, and a discharge port 26c. The volute chamber 26b spirally extends between the suction port 26a and the discharge port 26c. The impeller 28 is fixed to the rotary shaft 30a of the motor 30 and rotatably supported in the volute chamber 26b. The motor 30 receives power from the battery pack 2 and drives the impeller 28 to rotate. When the impeller 28 is rotationally driven, the air sucked from the suction port 26a is accelerated in the volute chamber 26b and then discharged from the discharge port 26c. The discharge nozzle 20 is connected to the discharge port 26 c of the volute case 26 . Although not particularly limited, in the blower 10 of this embodiment, when the user wears the blower 10 in a predetermined posture, the motor 30 is positioned between the user and the volute case 26, and the suction port 26a of the volute case 26 is , open toward the rear of the user (that is, toward the side opposite to the user).

Here, the discharge port 26c of the volute case 26 is positioned outside the outer case 14. As shown in FIG. The volute case 26 has a discharge duct 26d protruding from the outer case 14, and the discharge port 26c is positioned at the tip of the discharge duct 26d. The outer case 14 is provided with a duct opening 14c through which the discharge duct 26d passes. As described above, the outer case 14 supports the volute pump 12 via the plurality of vibration isolating members 13 . Therefore, a gap is provided between the discharge duct 26d and the duct opening 14c, which allows relative displacement of the volute case 26 with respect to the outer case 14. As shown in FIG.

On the other hand, most of the volute pump 12 including the motor 30 is located inside the outer case 14 . In particular, since the suction port 26a of the volute case 26 is positioned inside the outer case 14, the outer case 14 is provided with external suction ports 40a and 40b. The external suction ports 40 a and 40 b are one or more openings formed in the outer case 14 . Inside the outer case 14, air paths 42, 42a, 42b extending from the external suction ports 40a, 40b to the suction port 26a of the volute case 26 are defined.

Blower 10 further comprises a motor controller 32 . Motor controller 32 is electrically connected to battery terminal 18 a and motor 30 . Thereby, the discharged power of the battery pack 2 is supplied to the motor 30 via the motor controller 32 . The motor controller 32 incorporates one or more power switching elements and controls power supplied to the motor 30 . Although not particularly limited, the motor 30 in this embodiment is a brushless DC motor, and the motor controller 32 incorporates an inverter circuit. The motor controller 32 faces the air path 42 inside the outer case 14 . As a result, the temperature rise of the motor controller 32 can be suppressed by the air flowing through the air path 42 .

The motor controller 32 is attached to the unit holder 34 . The unit holder 34 is positioned inside the outer case 14 and assembled to the outer case 14 . In addition to the motor controller 32, the battery terminal 18a is also assembled to the unit holder 34. As shown in FIG. With such a configuration, the motor controller 32 and the battery terminal 18a are first assembled to the unit holder 34 in the manufacturing process of the blower 10 . Next, the unit holder 34 is assembled to the base member 14a of the outer case 14 together with the motor controller 32 and the battery terminal 18a. Since the motor controller 32 and the battery terminals 18a do not have to be individually assembled to the outer case 14, the motor controller 32 and the battery terminals 18a can be assembled easily.

A specific configuration of the unit holder 34 is not particularly limited. However, in the blower 10 of this embodiment, the unit holder 34 is assembled across both the base member 14a (first segment) and the cover member 14b (second segment). With such a configuration, the rigidity of the outer case 14 can be increased by the unit holder 34 . Moreover, since the unit holder 34 is stably fixed to the outer case 14, vibration of the motor controller 32 and the battery terminal 18a can be suppressed. As a result, it is possible to prevent electrical problems (for example, poor contact).

As described above, since the motor 30 is arranged inside the outer case 14, the noise of the motor 30 is suppressed from spreading to the surroundings. However, since the outer case 14 is formed with the external suction ports 40a and 40b, it is inevitable that the noise of the motor 30 leaks to the outside through the external suction ports 40a and 40b. Regarding this point, in the blower 10 of this embodiment, the external suction ports 40 a and 40 b are provided in the bottom portion 14 d of the outer case 14 . When the user wears the blower 10 in a predetermined posture, the bottom portion 14d of the outer case 14 faces the ground, and the external suction ports 40a and 40b open vertically downward. That is, when the user uses the blower 10, the external suction ports 40a and 40b of the outer case 14 open toward the ground. As a result, the noise leaking from the external suction ports 40a and 40b is mainly emitted toward the ground, and is suppressed from spreading to the surroundings.

Here, the suction port 26a of the volute case 26 opens in the horizontal direction in the above-described predetermined posture (that is, the posture when worn on the back of the user). That is, the direction in which the suction port 26a of the volute case 26 opens and the direction in which the external suction ports 40a and 40b of the outer case 14 open are orthogonal to each other. The opening direction of the suction port 26a of the volute case 26 is parallel to the rotating shaft 30a of the motor 30, that is, parallel to the rotating shaft of the impeller 28 as well.

The positions of the external suction ports 40 a and 40 b are not limited to the bottom portion 14 d of the outer case 14 . However, if the external suction ports 40a and 40b are positioned at the bottom portion 14d of the outer case 14, the external suction ports 40a and 40b are positioned relatively low when the user mounts the blower 10 in a predetermined posture. placed. Therefore, it is possible to effectively suppress the noise leaking from the external suction ports 40a and 40b from being diffused to the surroundings. From this point of view, the closer the external suction ports 40a and 40b to the bottom 14d of the outer case 14, the better. Therefore, the external suction ports 40 a and 40 b may be positioned below the rotating shaft 30 a of the motor 30 , and furthermore may be positioned below the volute case 26 .

In the blower 10 of this embodiment, the bottom portion 14d of the outer case 14 has a ground surface 44 that contacts the ground when the user places the blower 10 on the ground. However, the external suction ports 40 a and 40 b are provided at positions different from the ground surface 44 . If the external suction ports 40a and 40b were provided on the ground plane 44, when the user placed the blower 10 on the ground, the external suction ports 40a and 40b would be completely blocked by the ground. becomes a problem when the is continuing to rotate due to inertia. Therefore, at least a part of the external suction ports 40 a and 40 b can be provided at a position different from the ground surface 44 .

As shown in FIG. 4, in the blower 10 of this embodiment, the external suction ports 40a and 40b have a first external suction port 40a and a second external suction port 40b. The air paths 42, 42a, 42b have a first air path 42a extending upward from the first external suction port 40a and a second air path 42b extending upward from the second external suction port 40b. The first air path 42 a and the second air path 42 b are provided along the battery interface 18 and adjacent to the battery pack 2 attached to the battery interface 18 . According to such a configuration, the temperature rise of the battery pack 2 can be suppressed by the air flowing through the air paths 42a and 42b.

In particular, in the blower 10 of this embodiment, the battery interface 18 is provided between the first air path 42a and the second air path 42b. The first air path 42 a adjoins the battery pack 2 attached to one battery interface 18 , and the second air path 42 b adjoins the battery pack 2 attached to the other battery interface 18 . Thereby, the temperature rise of each battery pack 2 can be effectively suppressed.

In the blower 10 of this embodiment, the amount of air passing through the external suction ports 40 a and 40 b of the outer case 14 is 95% or more of the amount of air passing through the suction port 26 a of the volute case 26 . In other words, the outer case 14 has substantially no open openings other than the external suction ports 40a and 40b. This prevents the noise of the motor 30 from leaking to the outside of the outer case 14 from anything other than the external suction ports 40a and 40b.

Next, the structure of the volute case 26 will be described with reference to FIGS. 5 and 6. FIG. As shown in FIGS. 5 and 6, the volute case 26 has a case body 52 that defines the volute chamber 26b, and a bell mouth 54 that protrudes from the case body 52 and defines the suction port 26a. The bell mouth 54 has a frustum shape whose cross-sectional area increases from the suction port 26a toward the volute chamber 26b. The volute case 26 is made of a resin material and configured by combining a plurality of parts. Although not particularly limited, each part is manufactured by die molding.

In the volute case 26 , the thickness required for the bell mouth 54 (particularly, the end portion of the bell mouth 54 ) is greater than the thickness required for the case body 52 . Therefore, if the bell mouth 54 is formed integrally with the case main body 52, the part in which they are integrated will have an uneven thickness structure. In order to mold such a part with a mold with high accuracy, it is conceivable to provide a so-called thinned part in the thick bell mouth 54 portion. However, if the bell mouth 54 is made thin, a large number of holes and grooves are formed on the surface of the bell mouth 54, which causes a problem of wind noise.

Regarding the above points, the volute case 26 in this embodiment is constructed by combining a plurality of parts. In particular, the multiple parts that make up the volute case 26 include a first part 56 and a second part 58 . The first part 56 constitutes at least part of the case body 52 . The second part 58 is attached to the first part 56 and constitutes at least part of the bell mouth 54 . In this way, when at least part of the bell mouth 54 is made up of a component separate from the case body 52, the uneven thickness structure of the first component 56 that constitutes the case body 52 is eliminated or suppressed, and the bell mouth is It is possible to eliminate the need to provide the surface of 54 with undercuts. Thereby, the surface of the bell mouth 54 (in particular, the surface of the tip portion of the bell mouth 54) can be made smooth.

As an example, in this embodiment, the first part 56 also forms part of the bell mouth 54, and the second part 58 is an annular member that forms the tip of the bell mouth 54. there is When the second part 58 is an annular member, the suction port 26a of the volute case 26 can be precisely formed with a smooth surface.

In this embodiment, the first component 56 is provided with a plurality of recesses 56a. This is a cutout provided in the first part 56 . Similarly, the second part 58 is also provided with a plurality of recesses 58a. This is also the meat stealing provided in the second part 58 . However, these concave portions 56 a and 58 a are located on the mating surfaces of the first component 56 and the second component 58 . Therefore, when the first part 56 and the second part 58 are combined, these recesses 56a, 58a are located between the first part 56 and the second part 58 and are not exposed to the outside. Therefore, the surface (inner surface) of the bellmouth 54 can be formed smoothly while providing the respective parts 56 and 58 with thinned portions.

As shown in FIGS. 3, 4, and 7, the blower 10 includes a plurality of sound absorbing members 62, 64, 66, 68. As shown in FIG. A plurality of sound absorbing members 62 , 64 , 66 , 68 are positioned inside the outer case 14 . The plurality of sound absorbing members 62 , 64 , 66 , 68 includes a first sound absorbing member 62 , a second sound absorbing member 64 , a third sound absorbing member 66 and a fourth sound absorbing member 68 . Each sound absorbing member 62, 64, 66, 68 is made of sponge. The term "sponge" as used herein broadly means a spongy (or porous) material, and the material that constitutes it is not particularly limited. The sound absorbing members 62, 64, 66, 68 can be constructed of various materials such as resin materials and rubber materials.

The first sound absorbing member 62 is attached to the inner surface of the cover member 14 b of the outer case 14 and faces the suction port 26 a of the volute case 26 . The first sound absorbing member 62 is positioned on the extension line of the rotation shaft 30a of the motor 30, and can effectively absorb the noise of the motor 30. As shown in FIG. As described above, the impeller 28 is fixed to the rotating shaft 30a of the motor 30. As shown in FIG. Therefore, the first sound absorbing member 62 is also positioned on the extension line of the rotation axis of the impeller 28 . The first sound absorbing member 62 generally has a disc shape.

The second sound absorbing member 64 is attached to the inner surface of the base member 14 a of the outer case 14 and positioned between the base member 14 a and the motor 30 . The second sound absorbing member 64 is also positioned on the extension line of the rotating shaft 30a of the motor 30, and can effectively absorb the noise of the motor 30. As shown in FIG. The second sound absorbing member 64 is also positioned on the extension line of the rotation shaft of the impeller 28 . The second sound absorbing member 64 faces the first sound absorbing member 62 with the motor 30 interposed therebetween. By arranging the motor 30 between the two sound absorbing members 62 and 64, the noise of the motor 30 can be effectively absorbed.

The third sound absorbing member 66 is attached to the base member 14 a of the outer case 14 . The third sound absorbing member 66 has a tubular shape, and is arranged so as to surround the motor 30 in a radial direction perpendicular to the rotating shaft 30 a of the motor 30 . Here, at least part of the third sound absorbing member 66 may be formed integrally with the second sound absorbing member 64 . Further, the third sound absorbing member 66 does not necessarily have a cylindrical shape, and may have a simple plate shape and be provided only partially in the circumferential direction around the motor 30. .

The fourth sound absorbing member 68 is attached to the discharge duct 26 d of the volute case 26 and provided in the gap between the discharge duct 26 d of the volute case 26 and the duct opening 14 c of the outer case 14 . As described above, the outer case 14 supports the volute case 26 via the plurality of anti-vibration members 13 . Therefore, the volute case 26 can be displaced with respect to the outer case 14, and in order to allow the displacement, it is necessary to provide a gap between the discharge duct 26d and the duct opening 14c. However, if a gap is provided between the discharge duct 26d and the duct opening 14c, the noise of the motor 30 may leak out of the outer case 14 through the duct opening 14c. Since the fourth sound absorbing member 68 is made of flexible sponge while suppressing leakage of such noise, it is possible to allow relative displacement of the volute case 26 .

2: Battery pack 10: Blower 12: Volute pump 13: Anti-vibration member 14: Outer case 14a: Base member 14b: Cover member 14c: Duct opening 14d: Bottom 16: Shoulder strap 18: Battery interface 18a: Battery terminal 20: Discharge Nozzle 22: Operation grip 24: Trigger 26: Volute case 26a: Suction port 26b: Volute chamber 26c: Discharge port 26d: Discharge duct 28: Impeller 30: Motor 32: Motor controller 34: Unit holders 40a, 40b: External suction port 42 , 42a, 42b: air path 44: ground plane 52: case body 54: bell mouth 56: first member 58 of volute case: second member 62, 64, 66, 68 of volute case: sound absorbing member

Claims (9)

A blower held or worn by a user,
a volute case defining an inlet, a volute chamber and an outlet;
an impeller rotatably supported within the volute chamber;
a motor connected to the impeller and driving the impeller;
an outer case that houses the volute case and the motor;
a sound absorbing member located between the volute case and the outer case and located on an extension line of the rotating shaft of the motor;
with
The volute case has a discharge duct projecting to the outside of the outer case,
The outer case has a duct opening through which the discharge duct passes,
The blower further comprises a fourth sound absorbing member provided in a gap between the duct opening and the discharge duct.
blower. 2. The blower according to claim 1, wherein said sound absorbing member is also positioned on an extension of said impeller's rotation axis. 3. The blower according to claim 1, wherein said sound absorbing member faces said suction port of said volute case. The blower according to any one of claims 1 to 3, wherein the sound absorbing member is attached to the inner surface of the outer case. The blower according to any one of claims 1 to 4, wherein the sound absorbing member is made of sponge. The blower according to any one of claims 1 to 5, wherein the sound absorbing member has a first sound absorbing member and a second sound absorbing member that face each other with the motor interposed therebetween. The blower according to any one of claims 1 to 6, further comprising a cylindrical third sound absorbing member surrounding the motor in a radial direction perpendicular to the rotation axis of the motor. The blower according to any one of claims 1 to 7, wherein the outer case supports the volute case via at least one vibration isolating member. The blower according to any one of claims 1 to 8 , wherein the blower is a backpack type blower worn on the back of a user.

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