Blower

Abstract

The invention provides a blower. A blower disclosed in this specification may comprise: a prime mover; a fan driven by the prime mover; an air supply pipe through which the air flow generated by the fan flows; a plate part which is disposed inside the blast pipe and has a side surface that follows the direction in which the air flow flows; and a protruding portion that protrudes from the vicinity of the downstream end of the side surface of the plate portion in a direction that blocks the air flow.

Description

TECHNICAL FIELD

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

[0002] A blower is disclosed in Japanese Patent Application Publication No. 2022-123186. The blower includes a prime mover, a fan driven by the prime mover, an air supply duct through which an air flow generated by the fan flows, and a plate portion disposed inside the air supply duct and having a side surface along a direction in which the air flow flows. SUMMARY

[0003] In the blower described above, a vortex flow can sometimes be periodically generated at a downstream end of the plate portion. The frequency at which such a vortex flow is generated varies depending on the speed of the air flow, and thus varies depending on the rotational speed of the fan. Thus, depending on the rotational speed of the fan, the frequency at which the vortex flow is generated can coincide with a resonance frequency of the plate portion and the air supply duct or an acoustic resonance frequency of the air supply duct, thereby causing a large noise. In this specification, a technology capable of suppressing a case where a large noise is generated in a blower is provided.

[0004] The blower disclosed in this specification can include a prime mover, a fan driven by the prime mover, an air supply duct through which an air flow generated by the fan flows, a plate portion disposed inside the air supply duct and having a side surface along a direction in which the air flow flows, and a protruding portion protruding from a vicinity of a downstream end of the side surface of the plate portion toward a direction in which the air flow is blocked.

[0005] According to the above-described structure, since the protruding portion is provided in the vicinity of the downstream end of the plate portion, the generation of a periodic vortex flow at the downstream end of the plate portion can be suppressed. Thus, a case where a large noise is generated due to a resonance of the plate portion and the air supply duct, an acoustic resonance of the air supply duct can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 is a perspective view of a blower 2 of an embodiment.

[0007] Figure 2 is a cross-sectional view of a vicinity of an exhaust port 12 of the blower 2 of the embodiment.

[0008] Figure 3 is a side view showing an inside of a fan housing 24 of the blower 2 of the embodiment.

[0009] Figure 4 is a perspective view of a vicinity of an exhaust port 12 of the blower 2 of the embodiment.

[0010] Figure 5 is a cross-sectional view of a vicinity of an exhaust port 12 of the blower 2 of the embodiment.

[0011] Figure 6 FIG. 2 is a longitudinal sectional view of the vicinity of the exhaust port 12 of the blower 2 of the embodiment.

[0012] Figure 7 FIG. 6 is a graph showing the relationship between the motor rotation speed and the noise value of the blower 2 of the embodiment and the blower 2 of the comparative example.

[0013] Figure 8 FIG. 7 is a transverse sectional view of the vicinity of the exhaust port 12 of the blower 2 of the modification.

[0014] Figure 9 FIG. 8 is a transverse sectional view of the vicinity of the exhaust port 12 of the blower 2 of another modification.

[0015] Figure 10 FIG. 9 is a transverse sectional view of the vicinity of the exhaust port 12 of the blower 2 of still another modification. DETAILED DESCRIPTION

[0016] With reference to the accompanying drawings, representative and non-limiting embodiments of the present application are explained in detail below. The detailed description is intended only to illustrate preferred examples for carrying out the present application to those skilled in the art, and is not intended to limit the scope of the present application. In addition, the disclosed additional features and technical solutions can be used separately or jointly with other features, inventions to provide further improved blowers and methods of using and manufacturing the same.

[0017] In addition, the combination of features and processes disclosed in the following detailed description is not essential in the broadest sense in implementing the present application, and is described only for the purpose of specifically illustrating representative embodiments of the present application. Moreover, when providing additional and useful embodiments of the present application, various features of the following representative embodiments and various features described in the claims are not necessarily combined in the order as recited in the embodiments herein.

[0018] Unlike the structure of the features described in the embodiments and / or claims, all the features described in the specification and / or claims are intended to be disclosed separately and independently of each other, as a limitation on the original disclosure and the specific matters described in the claims. Moreover, all numerical ranges and descriptions relating to groups or populations are intended to disclose their intermediate structures, as a limitation on the original disclosure and the specific matters described in the claims.

[0019] In one or more embodiments, the height of the protrusion in the direction in which the air flow is shielded can be in the range of 1% to 50% of the plate thickness of the plate portion.

[0020] According to the above structure, it is possible to suppress the generation of periodic vortexes without greatly affecting the air supply amount of the blower.

[0021] In one or more embodiments, the width of the protrusion in the direction of the air flow can be in the range of 1% to 50% of the smallest width of the plate portion.

[0022] According to the above structure, it is possible to suppress the generation of periodic vortexes without greatly affecting the air supply amount of the blower.

[0023] In one or more embodiments, the protrusions can be provided discretely.

[0024] According to the above structure, it is possible to cause less impact on the air supply amount of the blower than when the protrusions are provided continuously.

[0025] In one or more embodiments, the protrusions can be provided continuously.

[0026] According to the above structure, it is possible to improve the workability of demolding when the plate portion provided with the protrusions is manufactured by one-piece molding using a resin material.

[0027] In one or more embodiments, the protrusions can be provided only on one side surface of the plate portion, and the protrusions can not be provided on the other side surface of the plate portion.

[0028] According to the above structure, it is possible to cause less impact on the air supply amount of the blower than when the protrusions are provided on both side surfaces of the plate portion.

[0029] In one or more embodiments, the prime mover can be an electric motor.

[0030] When an electric motor is used as the prime mover, the quietness during operation is higher than when an internal combustion engine is used as the prime mover, and therefore, if a large noise is generated, the comfort of the user can be greatly impaired. According to the above structure, it is possible to suppress the generation of a large noise in a blower in which an electric motor is used as the prime mover.

[0031] (Embodiment)

[0032] Figure 1 The illustrated blower 2 is provided with a housing 4, a fan 6 (see Figure 2 ), an electric motor 8 (see Figure 2The blower 2 includes an air intake 10, an exhaust port 12, a nozzle 14, a trigger switch 16, a locking button 18, and a power cord 20. The blower 2 is a handheld operating machine that can be held and used with one hand. The nozzle 14 can be selectively attached or detached from the air intake 10 or the exhaust port 12 depending on the operation performed using the blower 2. For example, when the blower 2 is used with the nozzle 14 attached to the exhaust port 12, it can perform a blowing operation by blowing air from the tip of the nozzle 14 to blow away fallen leaves, etc. Alternatively, when the blower 2 is used with the nozzle 14 attached to the air intake 10 and a dust collection bag (not shown) attached to the exhaust port 12, it can perform a suction operation by drawing air from the tip of the nozzle 14 to attract dust and collect it into the dust collection bag. Furthermore, in the following description, the direction of air flow at the exhaust port 12 is defined as the forward direction, and the opposite direction is defined as the backward direction. In addition, the direction of air flow at the intake 10 is defined as the right direction, and the opposite direction of the right direction is defined as the left direction. Furthermore, the direction orthogonal to the front-back direction and the left-right direction is defined as the up-down direction.

[0033] like Figure 2 As shown, the housing 4 includes a handle 22 for user gripping, a fan housing 24 for housing the fan 6, and a motor housing 26 for housing the electric motor 8. A trigger switch 16 and a locking button 18 are located on the handle 22. Additionally, the power cord 20 (see reference...) Figure 3 Connected to handle 22. If the user pulls into trigger switch 16 to open it, power is supplied from power cord 20 to electric motor 8, and fan 6 rotates. At this time, the speed of electric motor 8 varies according to the amount of pull in trigger switch 16. If the user removes their hand from trigger switch 16 to close it, the power supply from power cord 20 to electric motor 8 is cut off, and fan 6 stops rotating. If the user further presses locking button 18 while trigger switch 16 is pulled in, trigger switch 16 will remain in the pulled-in state even if the user subsequently removes their hand from locking button 18 and trigger switch 16. In this case, electric motor 8 maintains a state of rotating at any speed.

[0034] The intake port 10 connects the outside and inside of the fan housing 24. The intake port 10 has a cylindrical nozzle receiving portion 10a protruding to the left and a filter portion 10b that prevents foreign objects from entering the fan housing 24 from the intake port 10. The intake port 10 is arranged approximately coaxially with the rotation axis of the fan 6 inside the fan housing 24. The fan housing 24 and the motor housing 26 are connected via the motor exhaust port 28. Additionally, a motor intake port (not shown) is formed at the right end of the motor housing 26, connecting the outside and inside of the motor housing 26.

[0035] The fan 6 has a base 6a having a circular flat plate shape, a first fan 6b protruding toward the left from the left surface of the base 6a, and a second fan 6c protruding toward the right from the right surface of the base 6a. The first fan 6b and the second fan 6c each function as a centrifugal fan. In addition, as shown in Figure 3 the fan housing 24 has a volute portion 24a having a volute shape and a straight pipe portion 24b having a straight pipe shape. As shown in Figure 2 When the fan 6 rotates, air is introduced from the air intake port 10 into the volute portion 24a of the fan housing 24 by the first fan 6b and is pushed out from the radially inner side toward the radially outer side of the first fan 6b. In addition, when the fan 6 rotates, air is introduced from the motor exhaust port 28 into the volute portion 24a of the fan housing 24 by the second fan 6c and is pushed out from the radially inner side toward the radially outer side of the second fan 6c. At this time, air is introduced from the motor air intake port into the motor housing 26, and the air in the motor housing 26 flows into the fan housing 24 from the motor exhaust port 28, so the flow of air in the motor housing 26 is used to cool the electric motor 8. As shown in Figure 3 by the rotation of the first fan 6b and the second fan 6c, the air pushed out from the radially inner side toward the radially outer side flows along the inner surface of the radially outer side of the volute portion 24a, and thereafter, is sent out toward the front from the air exhaust port 12 via the straight pipe portion 24b.

[0036] As shown in Figure 2 the housing 4 has a left housing 30 that defines the left side portion of the fan housing 24, a middle housing 32 that defines the right side portion of the fan housing 24 and the left side portion of the motor housing 26, a right housing 34 that defines the right side portion of the motor housing 26 and the right side portion of the handle 22, and a handle housing 36 that defines the left side portion of the handle 22.

[0037] As shown in Figure 4As shown, the exhaust port 12 is located at the downstream end (i.e., the front end) of the straight pipe section 24b. A nozzle receiving portion 12a, protruding forward in a cylindrical shape, and a filter portion 12b, which prevents foreign objects from entering the fan housing 24 from the exhaust port 12, are formed in the exhaust port 12. In this embodiment, the filter portion 12b is composed of multiple plate portions 38. Each of the multiple plate portions 38 has a generally flat plate shape along the front-back direction and the left-right direction. The multiple plate portions 38 include a first right-side plate portion 38a, a first left-side plate portion 38b, a second right-side plate portion 38c, a second left-side plate portion 38d, a third right-side plate portion 38e, and a third left-side plate portion 38f. The first right-side plate portion 38a, the second right-side plate portion 38c, and the third right-side plate portion 38e are integrally formed seamlessly with the intermediate housing 32, extending to the left from the inner surface of the intermediate housing 32. The second right side plate 38c is disposed below the first right side plate 38a, and the third right side plate 38e is disposed below the second right side plate 38c. The first left side plate 38b, the second left side plate 38d, and the third left side plate 38f are integrally formed with the left side housing 30 without joints, extending to the right from the inner surface of the left side housing 30. The second left side plate 38d is disposed below the first left side plate 38b, and the third left side plate 38f is disposed below the second left side plate 38d.

[0038] like Figure 5 As shown, the first right side plate portion 38a and the first left side plate portion 38b are roughly aligned vertically. The vertical distance D1 from the uppermost part of the inner surface of the exhaust port 12 to the upper surface of the first right side plate portion 38a (or the upper surface of the first left side plate portion 38b) is in the range of 2 mm to 12 mm, for example, 11 mm. The vertical thickness of the first right side plate portion 38a and the first left side plate portion 38b is roughly the same. The vertical thickness T1 of the first right side plate portion 38a (or the first left side plate portion 38b) is in the range of 0.1 mm to 5 mm, for example, 1.5 mm. The left end of the first right side plate portion 38a and the right end of the first left side plate portion 38b abut against each other.

[0039] The second right side plate portion 38c and the second left side plate portion 38d are roughly aligned vertically. The vertical distance D2 from the lower surface of the first right side plate portion 38a (or the lower surface of the first left side plate portion 38b) to the upper surface of the second right side plate portion 38c (or the upper surface of the second left side plate portion 38d) is in the range of 2 mm to 12 mm, for example, 11.5 mm. The vertical thickness of the second right side plate portion 38c and the second left side plate portion 38d is roughly the same. The vertical thickness T2 of the second right side plate portion 38c (or the second left side plate portion 38d) is in the range of 0.1 mm to 5 mm, for example, 1.5 mm. In this embodiment, the vertical thickness T2 of the second right side plate portion 38c (or the second left side plate portion 38d) is roughly the same as the vertical thickness T1 of the first right side plate portion 38a (or the first left side plate portion 38b). The left end of the second right side plate 38c and the right end of the second left side plate 38d abut against each other.

[0040] The vertical positions of the third right side plate 38e and the third left side plate 38f are approximately the same. The vertical distance D3 from the lower surface of the second right side plate 38c (or the lower surface of the second left side plate 38d) to the upper surface of the third right side plate 38e (or the upper surface of the third left side plate 38f) is in the range of 2 mm to 12 mm, for example, 6 mm. The vertical distance D4 from the lower surface of the third right side plate 38e (or the lower surface of the third left side plate 38f) to the lowest part of the inner surface of the exhaust port 12 is in the range of 2 mm to 12 mm, for example, 6 mm. The vertical thickness of the third right side plate 38e and the third left side plate 38f is approximately the same. The vertical thickness T3 of the third right side plate 38e (or the third left side plate 38f) is in the range of 0.5 mm to 5 mm, for example, 1.5 mm. In this embodiment, the thickness T3 of the third right side plate portion 38e (or the third left side plate portion 38f) in the vertical direction is approximately the same as the thickness T2 of the second right side plate portion 38c (or the second left side plate portion 38d) in the vertical direction. The left end of the third right side plate portion 38e and the right end of the third left side plate portion 38f abut against each other.

[0041] like Figure 4 As shown, the first right side plate portion 38a, the second right side plate portion 38c, and the third right side plate portion 38e have a roughly right-angled trapezoidal shape when viewed from above, with the front side roughly orthogonal to the right side and the left side, and the length of the right side being greater than the length of the left side. The first left side plate portion 38b, the second left side plate portion 38d, and the third left side plate portion 38f also have a roughly right-angled trapezoidal shape when viewed from above, with the front side roughly orthogonal to the right side and the left side, and the length of the left side being greater than the length of the right side.

[0042] like Figure 6As shown in FIG. 1, the intersection C between the imaginary line obtained by extending the rear side edge and the imaginary line obtained by extending the left side edge (or the right side edge) is within a range of 1 mm to 50 mm, for example, 13 mm, in the front-rear direction of the front side edge when viewed from above the first right side plate portion 38a (or the first left side plate portion 38b). In addition, the angle θ that the rear side edge makes with the left side edge (or the right side edge) is within a range of 0.1 degrees to 90 degrees, for example, 45 degrees, when viewed from above the first right side plate portion 38a (or the first left side plate portion 38b). The second right side plate portion 38c (or the second left side plate portion 38d) and the third right side plate portion 38e (or the third left side plate portion 38f) also have the same features as the above-described features.

[0043] As shown in FIG. 1, the intersection C between the imaginary line obtained by extending the rear side edge and the imaginary line obtained by extending the left side edge (or the right side edge) is within a range of 1 mm to 50 mm, for example, 13 mm, in the front-rear direction of the front side edge when viewed from above the first right side plate portion 38a (or the first left side plate portion 38b). In addition, the angle θ that the rear side edge makes with the left side edge (or the right side edge) is within a range of 0.1 degrees to 90 degrees, for example, 45 degrees, when viewed from above the first right side plate portion 38a (or the first left side plate portion 38b). The second right side plate portion 38c (or the second left side plate portion 38d) and the third right side plate portion 38e (or the third left side plate portion 38f) also have the same features as the above-described features. Figure 4 As shown in FIG. 1, the intersection C between the imaginary line obtained by extending the rear side edge and the imaginary line obtained by extending the left side edge (or the right side edge) is within a range of 1 mm to 50 mm, for example, 13 mm, in the front-rear direction of the front side edge when viewed from above the first right side plate portion 38a (or the first left side plate portion 38b). In addition, the angle θ that the rear side edge makes with the left side edge (or the right side edge) is within a range of 0.1 degrees to 90 degrees, for example, 45 degrees, when viewed from above the first right side plate portion 38a (or the first left side plate portion 38b). The second right side plate portion 38c (or the second left side plate portion 38d) and the third right side plate portion 38e (or the third left side plate portion 38f) also have the same features as the above-described features. Figure 5 As shown in FIG. 1, the intersection C between the imaginary line obtained by extending the rear side edge and the imaginary line obtained by extending the left side edge (or the right side edge) is within a range of 1 mm to 50 mm, for example, 13 mm, in the front-rear direction of the front side edge when viewed from above the first right side plate portion 38a (or the first left side plate portion 38b). In addition, the angle θ that the rear side edge makes with the left side edge (or the right side edge) is within a range of 0.1 degrees to 90 degrees, for example, 45 degrees, when viewed from above the first right side plate portion 38a (or the first left side plate portion 38b). The second right side plate portion 38c (or the second left side plate portion 38d) and the third right side plate portion 38e (or the third left side plate portion 38f) also have the same features as the above-described features. Figure 6 As shown in FIG. 1, the intersection C between the imaginary line obtained by extending the rear side edge and the imaginary line obtained by extending the left side edge (or the right side edge) is within a range of 1 mm to 50 mm, for example, 13 mm, in the front-rear direction of the front side edge when viewed from above the first right side plate portion 38a (or the first left side plate portion 38b). In addition, the angle θ that the rear side edge makes with the left side edge (or the right side edge) is within a range of 0.1 degrees to 90 degrees, for example, 45 degrees, when viewed from above the first right side plate portion 38a (or the first left side plate portion 38b). The second right side plate portion 38c (or the second left side plate portion 38d) and the third right side plate portion 38e (or the third left side plate portion 38f) also have the same features as the above-described features.

[0044] In the present embodiment, the first right upper side protrusion 40a continuously extends in the left-right direction on the upper surface of the first right side plate portion 38a. Thus, in the case where the intermediate housing 32 is manufactured by integral molding using a resin material, demolding can be performed by linearly moving a mold that defines the shape of the first right side plate portion 38a and the first right upper side protrusion 40a in the left direction. In addition, the first left upper side protrusion 40b continuously extends in the left-right direction on the upper surface of the first left side plate portion 38b. Thus, in the case where the left side housing 30 is manufactured by integral molding using a resin material, demolding can be performed by linearly moving a mold that defines the shape of the first left side plate portion 38b and the first left upper side protrusion 40b in the right direction.

[0045] Figure 7It is a graph showing the effect of the presence or absence of the first upper right protrusion 40a and the first upper left protrusion 40b on the noise when using the blower 2. Figure 7 The "no countermeasure" curve represents the noise level when blower 2 is used without the first upper right protrusion 40a and the first upper left protrusion 40b. From Figure 7 It can be seen that, under these conditions, the noise from blower 2 becomes particularly loud at a specific motor speed. This can be attributed to the fact that, without the first upper right protrusion 40a and the first upper left protrusion 40b, eddies are periodically generated at the front ends of the first right side plate 38a and the first left side plate 38b. At a specific motor speed, the frequency at which these eddies are generated coincides with the resonant frequency of the multiple plate sections 38 and the straight pipe section 24b, or the acoustic resonant frequency of the straight pipe section 24b, thereby causing the multiple plate sections 38 and the straight pipe section 24b to resonate or the straight pipe section 24b to acoustically resonate.

[0046] In contrast, Figure 7 The "countermeasure" curve represents the noise level when using blower 2 with the first upper right protrusion 40a and the first upper left protrusion 40b. From Figure 7 It can be seen that, under these circumstances, the noise when using blower 2 will not become particularly loud at a specific motor speed. This can be attributed to the fact that by utilizing the first upper right protrusion 40a and the first upper left protrusion 40b to suppress the generation of periodic vortices at the front ends of the first right side plate portion 38a and the first left side plate portion 38b, the resonance of the multiple plate portions 38 and the straight pipe portion 24b or the acoustic resonance of the straight pipe portion 24b is suppressed.

[0047] (Modified Example)

[0048] The first right side plate 38a, the second right side plate 38c, and the third right side plate 38e can also be constructed from components independent of the intermediate housing 32, or can be fixed to the intermediate housing 32, for example, using fasteners or adhesives. The first left side plate 38b, the second left side plate 38d, and the third left side plate 38f can also be constructed from components independent of the left side housing 30, or can be fixed to the left side housing 30, for example, using fasteners or adhesives. The first right side plate 38a, the first left side plate 38b, the second right side plate 38c, the second left side plate 38d, the third right side plate 38e, and the third left side plate 38f can also have shapes different from those described in the above embodiments. The left end of the first right side plate 38a and the right end of the first left side plate 38b may not abut against each other. The left end of the second right side plate 38c and the right end of the second left side plate 38d may also not abut against each other. The left end of the third right side plate 38e and the right end of the third left side plate 38f may not abut against each other.

[0049] The first upper right protrusion 40a can be constructed from a component independent of the first right side plate 38a, or it can be fixed to the first right side plate 38a, for example, using fasteners or adhesives. The first upper left protrusion 40b can be constructed from a component independent of the first left side plate 38b, or it can be fixed to the first left side plate 38b, for example, using fasteners or adhesives.

[0050] The first upper right protrusion 40a (or the first upper left protrusion 40b) may also be disposed away from the front end of the first right side plate portion 38a (or the first left side plate portion 38b), for example, it may be disposed within a range from the front end to a predetermined distance (e.g., 5 mm) from the front end in the front-rear direction. In addition, when the first right side plate portion 38a (or the first left side plate portion 38b) is viewed from above, the direction in which the first upper right protrusion 40a (or the first upper left protrusion 40b) extends may also be tilted relative to the left-right direction.

[0051] like Figure 8 As shown, the first upper right protrusion 40a and the first upper left protrusion 40b may not be formed continuously in the left-right direction, or they may be formed discretely in the left-right direction.

[0052] like Figure 9 As shown, protrusions 40 may also be formed on plate portions 38 other than the first right-side plate portion 38a and the first left-side plate portion 38b. Figure 9 In the example shown, Figure 5 Based on the example shown, a second upper right protrusion 40c is formed on the upper surface of the second right side plate portion 38c, and a second upper left protrusion 40d is formed on the upper surface of the second left side plate portion 38d. The position and / or shape of the second upper right protrusion 40c and the second upper left protrusion 40d may be substantially the same as, or different from, the position and / or shape of the first upper right protrusion 40a and the first upper left protrusion 40b.

[0053] like Figure 10 As shown, a protrusion 40 may also be formed on the lower surface of the plate portion 38. Figure 10 In the example shown, Figure 9On the basis of the example shown, a third right upper side protruding portion 40e is formed on the upper surface of the third right side plate portion 38e, and a third left upper side protruding portion 40f is formed on the upper surface of the third left side plate portion 38f. In addition, a first right lower side protruding portion 40g is formed on the lower surface of the first right side plate portion 38a, and a first left lower side protruding portion 40h is formed on the lower surface of the first left side plate portion 38b. A second right lower side protruding portion 40i is formed on the lower surface of the second right side plate portion 38c, and a second left lower side protruding portion 40j is formed on the lower surface of the second left side plate portion 38d. A third right lower side protruding portion 40k is formed on the lower surface of the third right side plate portion 38e, and a third left lower side protruding portion 40l is formed on the lower surface of the third left side plate portion 38f.

[0054] The number of plate portions 38 can be more than or less than the above-described embodiment.

[0055] The blower 2 can also be provided with a propeller fan (not shown) or an axial fan (not shown) instead of the fan 6.

[0056] The blower 2 can also be provided with an internal combustion engine (not shown) instead of the electric motor 8 as the prime mover that rotates the fan 6. Alternatively, the blower 2 can also be provided with another type of electric motor (not shown), such as a brushless motor, instead of the electric motor 8.

[0057] The blower 2 can also be provided with a battery mounting portion (not shown) that can attach and detach a rechargeable battery pack (not shown) instead of the power supply cord 20. In this case, the electric motor 8 can also operate using power supplied from the battery pack.

[0058] (Features of the Embodiments)

[0059] As described above, in one or more of the embodiments, the blower 2 is provided with: an electric motor 8 (example of a prime mover); a fan 6 that is driven by the electric motor 8; a straight pipe portion 24b (example of a blast pipe) through which an air flow generated by the fan 6 flows; a plate portion 38 that is disposed inside the straight pipe portion 24b and has a side surface along a direction in which the air flow flows; and a protruding portion 40 that protrudes from a vicinity of a downstream end of the side surface of the plate portion 38 in a direction in which the air flow is blocked.

[0060] According to the above-described structure, since the protruding portion 40 is provided in the vicinity of the downstream end of the plate portion 38, generation of periodic vortex flow at the downstream end of the plate portion 38 can be suppressed. Thus, a case in which a large amount of noise is generated due to resonance of the plate portion 38 and the straight pipe portion 24b or acoustic resonance of the straight pipe portion 24b can be suppressed.

[0061] In one or more of the embodiments, in the direction in which the air flow is blocked, the height of the protruding portion 40 is in a range of 1% to 50% of the plate thickness of the plate portion 38.

[0062] According to the above structure, it is possible to suppress the generation of periodic vortexes without causing a large influence on the air supply amount of the blower 2.

[0063] In one or more embodiments, the width of the protrusion 40 in the direction of the air flow is in the range of 1% to 50% of the smallest width of the plate portion 38.

[0064] According to the above structure, it is possible to suppress the generation of periodic vortexes without causing a large influence on the air supply amount of the blower 2.

[0065] In one or more embodiments, the protrusions 40 are provided discretely.

[0066] According to the above structure, it is possible to cause a relatively slight influence on the air supply amount of the blower 2, as compared with the case where the protrusions 40 are provided continuously.

[0067] In one or more embodiments, the protrusions 40 can also be provided continuously.

[0068] According to the above structure, it is possible to improve the workability of demolding when the plate portion 38 provided with the protrusions 40 is manufactured by integral molding using a resin material.

[0069] In one or more embodiments, the protrusions 40 are provided only on one side (e.g., the upper surface) of the plate portion 38, and are not provided on the other side (e.g., the lower surface) of the plate portion 38.

[0070] According to the above structure, it is possible to cause a relatively slight influence on the air supply amount of the blower 2, as compared with the case where the protrusions 40 are provided on both sides of the plate portion 38.

[0071] In one or more embodiments, the electric motor 8 functions as a prime mover that drives the fan 6.

[0072] In the case where the electric motor 8 is used as the prime mover, the quietness during operation is higher as compared with the case where an internal combustion engine (not shown) is used as the prime mover, and therefore, if a large noise is generated, the comfort of the user is greatly impaired. According to the above structure, in the blower 2 that uses the electric motor 8 as the prime mover, it is possible to suppress the generation of a large noise.

Claims

1. A blower, wherein the blower is provided with: a prime mover; a fan driven by the prime mover; a blow pipe through which an air stream generated by the fan flows; a plate portion disposed inside the blow pipe, having a side surface along a direction in which the air stream flows; and a protruding portion protruding from a vicinity of a downstream end of the side surface of the plate portion in a direction in which the air stream is shielded.

2. The blower according to claim 1, wherein a height of the protruding portion in the direction in which the air stream is shielded is within a range of 1% to 50% of a plate thickness of the plate portion.

3. The blower according to claim 1 or 2, wherein a width of the protruding portion in the direction in which the air stream flows is within a range of 1% to 50% of a smallest width of the plate portion.

4. The blower according to any one of claims 1 to 3, wherein the protruding portion is provided discretely.

5. The blower according to any one of claims 1 to 3, wherein the protruding portion is provided continuously.

6. The blower according to any one of claims 1 to 5, wherein the protruding portion is provided only on one of the side surfaces of the plate portion, and is not provided on the other side surface of the plate portion.

7. The blower according to any one of claims 1 to 6, wherein the prime mover is an electric motor.

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