JP6731714B2 - Blower - Google Patents

Description

The present invention relates to a blower device such as a hair dryer having a suction grill provided at a suction port, and more particularly to a blower device capable of reducing the amount of blown noise during use.

With respect to the present invention, a grill structure in which the suction port is covered with double suction grilles inside and outside is known in the heating blower of Patent Document 1. There, a filter mounting frame having a bellmouth-shaped frame inner surface is detachably attached to the inlet of the round tubular main body, and an inner filter and an outer filter are arranged on each of the inner peripheral surface and the outer peripheral surface. doing. Each of the inner filter and the outer filter is made of a metal mesh material and formed into a dome shape with an outer bulge.

In the hair dryer according to the present invention, the suction grill disposed adjacent to the blower fan is formed in the shape of an inwardly recessed dome, and such a grill structure is known in Patent Document 2. There, an indented dome-shaped intake port guard (suction grille) is attached to the cylindrical intake port. Further, the outer diameter of the fan with respect to the inner diameter of the main body case is set to 80% or less to eliminate the generation of frictional vortex between the fan and the fan guide and reduce the vortex sound (noise).

JP, 2009-028437, A (paragraph number 0022, Drawing 5). JP-A-59-118105 (page 2, left column, lines 9 to 11, FIG. 1)

According to the heating air blower of Patent Document 1, it is possible to prevent dust from entering with the double inner and outer filters and the outer filter to improve dust removal performance. Further, since the inner surface of the frame of the filter mounting frame is formed in a bell mouth shape, it is possible to reduce the ventilation resistance on the inner surface of the frame and increase the air volume. However, the heating air blower of Patent Document 1 merely provides an inner filter and an outer filter in order to improve the dust removal performance, and there is no description mentioning reduction of air blow noise.

In the hair dryer of Patent Document 2, the outer diameter of the fan relative to the inner diameter of the main body case is set to 80% or less, and the generation of friction vortex flow between the fan and the fan guide is eliminated to reduce vortex noise (noise). However, like the heating air blower of Patent Document 1, regarding the reduction of the noise amount of the air intake guard and the air blow noise, there is no description that mentions the relationship between the two.

Hair dryers in recent years are required to be capable of delivering a large amount of dry air with high output in order to improve the drying capacity, and to be small and compact for easy handling. In order to increase the dry air volume, it is effective to increase the fan diameter of the blower fan, but if this is done, the blower part becomes large and the hair dryer cannot be made compact and compact. In many cases, the drying air of the hair dryer is made large by increasing the driving speed by keeping the fan diameter of the blower fan small. However, when the driving rotation speed of the blower fan is increased, the noise amount of the hair dryer is unavoidably increased. Especially, when the driving rotation speed of the blower fan is around 10,000 rpm, the air velocity sucked into the blower fan becomes large. As a result, a large irritating blast noise is likely to occur.

An object of the present invention is to provide a blower device that can significantly suppress the blower noise and reduce the noise of the entire device to reduce the noise.
An object of the present invention is to provide a blower device which can improve the structures of a suction grill and a blower fan to significantly suppress the blower noise, and can reduce the overall noise and reduce the noise at a lower cost than a conventional noise prevention structure. It is in.

Most of the noise of blowers such as hair dryers is caused by the rotation of the blower fan (rotational noise), the noise generated by the fan blades of the blower fan (blade noise), and the turbulence of the flow. Noise (turbulent noise) and noise due to resonance of the space inside the fan case (resonance noise). It is also known that turbulent noise is likely to be large in a blower in which the ventilation distance from the suction grill to the blower fan is larger than the fan diameter. This is because most of the air flow that passes through the suction grill and is sucked into the blower fan is biased toward the peripheral edge of the suction grill, and the inner surface of the center of the suction grill that faces the fan boss passes through the suction grill. This is because the air flow is stagnant, a vortex is generated, and turbulent noise is increased. The present inventors have re-examined the structure of a conventional air blower based on these findings, and in particular, repeated trial and error and experiments on turbulent noise, have reached the principle of the present invention, and propose the present invention. It came to.

In the blower device according to the present invention, the fan case 6 that supports the motor 5 and the blower fan 4 and covers at least the periphery of the blower fan 4 is disposed inside the main body case 1 having the rear opening 9 and the blowout port 13. is there. The fan case 6 is arranged in the main body case 1 such that the inlet 6a and the outlet 6b thereof are located between the rear opening 9 of the main body case 1 and the air outlet 13. As shown in FIG. 1, at the inlet 6a of the fan case 6, a suction grill 11 that covers the inlet 6a is arranged. The suction grill 11 includes a ventilation screen 23 and a mounting portion 24 provided on the periphery of the ventilation screen 23. The ventilation screen 23 is characterized by being bulged from the inlet 6a of the fan case 6 toward the blower fan 4 in a state where the mounting portion 24 is mounted and fixed to the inlet 6a of the fan case 6. In addition, "the fan case 6 is arranged in the main body case 1 such that the inlet 6a and the outlet 6b thereof are located between the rear opening 9 and the outlet 13 of the main body case 1" means that the rear opening 9 Does not mean that the inlet 6a of the fan case 6 is located in front of the rear opening 9 with reference to. For example, the inlet 6a of the fan case 6 may project rearward from the rear opening 9, and in that case, the front cylinder 45 and the rear cylinder of the intake body 12 are provided between the inlet 6a of the fan case 6 and the rear opening 9. By covering with 46, the external air can be smoothly introduced into the fan case 6.

As shown in FIG. 6, the mounting portion 24 of the suction grill 11 includes an inner engagement wall 60 on the periphery of the ventilation screen 23 and an outer engagement wall 61 that is bent in an L-shape continuously from the inner engagement wall 60. It is configured as a multiple cylinder. When the mounting portion 24 is mounted on the inlet 6 a of the fan case 6, the outer engagement wall 61 is engaged with the outer peripheral surface of the fan case 6.

Engaging claws 62 are integrally provided at a plurality of locations on the outer engaging wall 61, and engaging ribs 63 corresponding to the engaging claws 62 are provided on the outer peripheral surface of the fan case 6 so as to project. In a state where the mounting portion 24 is mounted on the inlet 6a of the fan case 6, the engaging claws 62 and the engaging ribs 63 engage with each other to fix the suction grill 11 to the fan case 6 so as not to move relative to each other.

The ventilation screen 23 of the suction grill 11 is bulged toward the blower fan 4 in an inwardly curved shape.

As shown in FIG. 11, the facing distance between the curved top 40 of the suction grill 11 and the fan boss 4b of the blower fan 4 is a, and the front-back distance from the mounting portion 24 of the suction grill 11 to the curved top 40 of the ventilation screen 23 is b. In this case, the suction grill 11 is arranged such that the facing distance a and the front-rear distance b satisfy the inequality (a<b).

An air intake body 12 having a suction port 29 is attached to the rear opening 9 of the main body case 1. The air intake body 12 includes a cylindrical wall 32 that guides the air flowing in from the suction port 29 toward the ventilation screen 23. The mounting portion 24 of the suction grill 11 is located in front of the front end of the cylinder of the air intake body 12.

When the front-rear distance from the mounting portion 24 of the suction grill 11 to the curved top portion 40 of the ventilation screen 23 is b, and the front-rear distance from the opening surface of the suction port 29 of the air intake body 12 to the ventilation hole 25 of the suction grill 11 is e. , The suction grille 11 is arranged so that the front-rear distance b and the front-rear distance e satisfy the inequality (b<e).

When the front-rear distance from the opening surface of the suction port 29 of the air intake body 12 to the mounting portion 24 of the suction grill 11 is d, and the facing distance between the mounting portion 24 of the suction grill 11 and the fan blade 4a of the blower fan 4 is c. , The suction grille 11 is arranged so that the front-rear distance d and the facing distance c satisfy the inequality (c<d).

A suction port 29 is provided at the rear end of the cylinder of the air intake body 12, and a delivery port 31 is provided at the front end of the cylinder. When the opening area of the suction port 29 of the intake body 12 is C and the opening area of the delivery port 31 is D, the opening area C and the opening area D are set so as to satisfy the inequality (C<D).

Each of the suction port 29 and the delivery port 31 of the air intake body 12 is formed in a tubular shape, and a space between the two 29 and 31 is made continuous by an expanding tubular wall 32 having a gently curved cross section (see FIG. 1).

A rectifying screen 30 that also serves as the first filter 47 is arranged facing the suction port 29 of the air intake body 12.

As shown in FIG. 3, the rectifying screen 30 includes a plurality of concentric rectifying ribs 56 and cross ribs 57 that support the plurality of rectifying ribs 56.

When the air intake body 12 is attached to the rear opening 9 of the main body case 1, the cylinder front end of the delivery port 31 cooperates with the fan case 6 to clamp the attachment portion 24 of the suction grille 11.

As shown in FIG. 5, the thickness T of the ventilation screen 23 of the suction grill 11 is set to be smaller than the rib length L1 of the flow regulating ribs 56 in the ventilation direction.

The rib thickness L2 of the flow regulating rib 56 is set to be smaller than the rib length L1 of the flow regulating rib 56 in the ventilation direction.

A second filter 48 having a mesh structure having a group of ventilation holes 48 a smaller than the first filter 47 is arranged on the side of the rectifying screen 30 facing the suction grill 11.

The second filter 48 is formed of a flexible sheet-shaped soft material, and the rectifying screen 30 is formed of a material harder than the second filter 48. The second filter 48 and the rectifying screen 30 are arranged adjacent to each other.

The intake body 12 includes a front cylinder 45 having a cylinder wall 32 and a rear cylinder 46 having a suction port 29. The peripheral edge of the second filter 48 is sandwiched between the front cylinder 45 and the rear cylinder 46.

A center receiving frame 49 and a support frame 50 for supporting the same frame 49 are provided on the cylinder end surface 51 of the front cylinder 45 adjacent to the rear cylinder 46 so as to be flush with the cylinder end surface 51. The second filter 48 is fixed to the cylinder end surface 51, the central receiving frame 49, and the support frame 50.

A holding ring 68 having a cylinder wall 69 that covers the peripheral edge of the second filter 48 is arranged around the cylinder end surface 51 of the front cylinder 45. The rear cylinder 46 is attached to the rear opening 9 of the main body case 1. With the rear cylinder 46 mounted in the rear opening 9, the pressing ring 68 mounted around the cylinder end surface 51 of the front cylinder 45 is pressed and fixed by the rear cylinder 46 toward the front cylinder 45.

With the rear cylinder 46 attached to the rear opening 9, the front and rear surfaces of the second filter 48 are sandwiched between the central receiving frame 49, the support frame 50 and the rectifying screen 30.

With the rear cylinder 46 attached to the rear opening 9, a gap E is secured between the second filter 48 and the cylinder front end of the rear cylinder 46.

Control boards 90 and 91 for controlling the operating state of the blower are arranged in a clearance space formed between the main body case 1 and the fan case 6.

The blower fan 4 is configured by disposing a plurality of fan blades 4a around the fan boss 4b. A front concave-convex edge 85 and a rear concave-convex edge 86 for reducing fan noise are formed on each of the blade leading edge on the lower side in the rotation direction of the fan blade 4a and the blade trailing edge on the upper side in the rotation direction of the fan blade 4a.

The adjacent pitch P1 of the concave portions 85a of the front concave-convex edge 85 is set to be larger than the adjacent pitch P2 of the concave portions 86a of the rear concave-convex edge 86.

The uneven depth j1 of the front uneven edge 85 is set to be smaller than the uneven depth j2 of the rear uneven edge 86.

Each of the concave portion 85a of the front concave-convex edge 85 and the concave portion 86a of the rear concave-convex edge 86 is formed by a curved edge. The curvature radius k1 of the concave portion 85a of the front concave-convex edge 85 is set to be larger than the curvature radius k2 of the concave portion 86a of the rear concave-convex edge 86.

The fan blade 4a is made of a fiber reinforced plastic material.

In the blower according to the present invention, the suction grill 11 is arranged at the inlet 6a of the fan case 6, and the previous inlet 6a is covered with the ventilation screen 23 of the suction grill 11. In addition, the ventilation screen 23 is bulged from the inlet 6a of the fan case 6 toward the blower fan 4 to reduce the resonance space in the fan case 6 and to form a space in which the air flow is likely to stay and generate a swirl. I was able to solve the problem. Therefore, as compared with the conventional device in which it was inevitable to form a stagnant space in the center of the suction grill where turbulent noise is likely to occur, amplification of noise due to resonance can be suppressed and the amount of turbulent noise generated can be reduced. It is possible to provide a blower device that can be significantly suppressed, and the noise level of the overall noise can be reduced accordingly and the noise can be reduced. Further, since the mounting portion 24 provided on the periphery of the ventilation screen 23 is mounted and fixed to the inlet 6a of the fan case 6, the ventilation screen 23 prevents the fan case 6 from vibrating, and the fan case 6 vibrates. It is possible to reduce the generation of noise accompanying this.

With the inner engagement wall 60 and the outer engagement wall 61 that is continuous with the inner engagement wall 60, the mounting portion 24 is configured in a multi-cylinder shape, and the mounting portion 24 is mounted on the inlet 6 a of the fan case 6 in an external engagement state. The joint wall 61 is adapted to engage with the outer peripheral surface of the fan case 6. Specifically, in a state where the outer engagement wall 61 is attached to the fan case 6, the inner engagement wall 60 and the outer engagement wall 61 sandwich the cylindrical wall of the fan case 6 inside and outside. According to such a mounting structure of the suction grille 11, the suction grille 11 can be fixed to the fan case 6 in a state in which it cannot be moved in the radial direction, and the structural strength of the fan case 6 can be secured by the outer engagement wall 61 that closely contacts the peripheral surface of the case. Can be increased. Therefore, it is possible to surely prevent the fan case 6 and the suction grill 11 that have been subjected to the vibration of the motor 5 from vibrating independently or colliding with each other to generate the vibration noise, thereby reducing the blowing noise.

In a state where the mounting portion 24 is mounted on the inlet 6a of the fan case 6, when the suction grille 11 is fixed to the fan case 6 so as not to be movable relative to each other by the engaging claws 62 and the engaging ribs 63 which engage with each other, the suction grille 11 is fixed. It can be more firmly fixed to the fan case 6. Specifically, in addition to the outer engagement wall 61 being in close contact with the case peripheral surface of the fan case 6, the engagement claws 62 and the engagement ribs 63 are engaged with each other, whereby the suction grille 11 moves in the ventilation direction. The mounting portion 24 can be tightly fixed to the end surface of the inlet 6a. Therefore, it is possible to further reliably prevent the fan case 6 and the suction grill 11 that are subjected to the vibration of the motor 5 from vibrating independently or colliding with each other to generate vibration noise, thereby reducing the blowing noise.

If the bulging shape of the ventilation screen 23 is formed in a curved shape that is recessed inward toward the blower fan 4, the cross-sectional structure of the ventilation screen 23 is simplified as much as possible, and a resonance space is created between the ventilation screen 23 and the blower fan 4. It is possible to effectively eliminate the formation of a space or the formation of a space in which a swirl is likely to occur. Further, since the sectional structure can be simplified, the processing cost of the ventilation screen 23 can be reduced and the cost for noise reduction can be saved.

When the front-rear distance b from the mounting portion 24 of the suction grille 11 to the curved top 40 is set to be larger than the facing distance a between the curved top 40 and the fan boss 4b, turbulent noise is generated between the ventilation screen 23 and the fan boss 4b. It is possible to increase the degree of curvature of the indented ventilation screen 23 while eliminating the formation of an easily retained space. Further, as the bending degree of the ventilation screen 23 increases, the area of the peripheral portion of the ventilation screen 23 that faces the region where the flow velocity of the air flow is large increases, so that the passage amount of the air flow in the center of the ventilation screen 23 can be reduced. Therefore, it is possible to prevent the air flow from staying in the space between the ventilation screen 23 and the fan boss 4b and generate a vortex flow, thereby reliably preventing turbulent noise.

When the intake body 12 having the suction port 29 is provided in the rear opening 9 and the cylinder wall 32 is provided in the intake body 12, the airflow flowing from the suction port 29 is guided to the cylinder wall 32 and flows to the suction grill 11. Can be rectified in between. Therefore, the amount of noise can be reduced by eliminating the formation of the retention space where turbulent noise is likely to occur between the suction grill 11 and the suction port 29. Further, since the noise generated by the blower fan 4 is shielded by the cylinder wall 32 and the amount of noise radiated from the suction port 29 can be reduced, the noise reduction effect of the suction grill 11 is combined with the overall noise to be further effective. It can be reduced to silent. Therefore, as compared with the conventional noise prevention structure, it is possible to provide an air blower that can reduce the total noise and reduce the noise at low cost.

If the front-rear distance e from the opening surface of the suction port 29 to the ventilation hole 25 of the ventilation screen 23 is set to be larger than the front-rear distance b from the mounting portion 24 to the curved top 40, it reaches the ventilation screen 23 from the suction port 29. The air flow can be rectified by the cylindrical wall 32 of the intake body 12 to suppress the generation of turbulent flow inside the intake body 12. Further, the rotation noise of the blower fan 4 and the blade noise of the fan blade 4a can be attenuated by the cylindrical wall 32. Therefore, the overall noise of the blower can be reduced by the synergistic effect of suppressing the turbulent noise by the ventilation screen 23 and the noise damping effect by the cylindrical wall 32.

When the front-rear distance d from the opening surface of the suction port 29 to the mounting portion 24 is set to be larger than the facing distance c between the mounting portion 24 and the fan blade 4a, the blade edge of the fan blade 4a is sucked by the suction port 29. The arriving airflow can be rectified by the cylinder wall 32 and the ventilation screen 23 to suppress the generation of turbulence inside the air intake body 12 and inside the fan case 6 facing the ventilation screen 23. Further, the rotation noise of the blower fan 4 and the blade noise of the fan blades 4a can be attenuated by the ventilation screen 23 and the cylindrical wall 32. Therefore, in addition to the effect of reducing the turbulent noise due to the ventilation screen 23, the noise of the ventilation screen 23 and the cylindrical wall 32 can be attenuated, thereby further reducing the overall noise of the blower.

If the opening area D of the air outlet 31 of the cylindrical wall 32 is set to be larger than the opening area C of the air inlet 29, the rotation noise of the blower fan 4 passing through the ventilation screen 23 and the blade noise of the fan blades 4a will be It is possible to reduce the amount of noise emitted from the suction port 29 and further reduce the overall noise of the hair dryer by confining the leak to the side of 29 with the suction port 29 having a small opening area.

When the inlet 29 and the outlet 31 of the air intake body 12 are made continuous with each other by the expanding cylindrical wall 32 whose section is gently curved, the air flow from the inlet 29 to the outlet 31 becomes smoother. As a result, the sucked air can be efficiently fed to the fan blades 4a of the blower fan 4. Therefore, it is possible to enhance the blowing amount of the dry wind fed from the blowing fan 4 and improve the blowing ability of the hair dryer. Further, by smoothing the flow of air from the suction port 29 to the delivery port 31, it is possible to reliably prevent the generation of a vortex inside the expanding cylindrical wall 32.

By arranging the rectifying screen 30 that also functions as the first filter 47 facing the suction port 29 of the air intake body 12, the air flow that has flowed in from the suction port 29 can be rectified by the rectification screen 30 and further can be rectified by the cylindrical wall 32. The rectification effect by the intake body 12 can be further improved. Further, since the rectifying screen 30 also functions as the first filter 47 that prevents large dust, hair, and the like from being sucked together with the air, the rectifying screen 30 is prevented from being contaminated by the devices arranged on the leeward side and has a blowing function. It also helps prevent the drop.

According to the rectifying screen 30 composed of the plurality of rectifying ribs 56 arranged concentrically and the crossing ribs 57 supporting the plurality of rectifying ribs 56, when the airflow flowing from the suction port 29 passes through the rectifying screen 30, The amount of noise generated can be reduced to contribute to noise reduction. For example, in the case of a rectifying screen having a ventilation surface of a honeycomb structure, a higher rectifying effect can be obtained, but since the airflow collides with the honeycomb structure and a large amount of noise is generated, the blast noise is reduced and the noise is reduced. Not suitable for.

When the mounting portion 24 of the suction grill 11 is sandwiched between the front end of the delivery port 31 and the fan case 6 in a state where the intake body 12 is mounted in the rear opening 9 of the main body case 1, the suction grill 11 mounted in the fan case 6 is , Can be fixed more firmly.

If the thickness T of the ventilation screen 23 of the suction grill 11 is set to be smaller than the rib length L1 of the rectifying rib 56 in the ventilation direction, it is possible to enhance the rectifying effect by the suction port 29 and enhance the silent effect.

If the rib thickness L2 of the rectifying rib 56 is set to be smaller than the rib length L1 of the rectifying rib 56 in the ventilation direction, the suction port 29 is blocked by the rectifying rib 56 while surely exhibiting the rectifying effect. Since the resistance can be prevented from increasing, the blowing efficiency of the blowing fan 4 can be improved.

If a second filter 48 having a mesh structure having a group of ventilation holes 48a smaller than the first filter 47 is arranged on the side of the rectifying screen 30 facing the suction grill 11, small dust, hair, etc. can be removed from the suction grill 11. It can be reliably prevented from being sucked to the side.

If the second filter 48 is made of a sheet-shaped soft material and the rectifying screen 30 is made of a material harder than the second filter 48, the second filter 48 made of a soft material can be protected by the rectifying screen 30. For example, the rectifying screen 30 can prevent the second filter 48 from being excessively bent and deformed to be damaged when dust or the like attached to the second filter 48 is sucked and removed by a vacuum cleaner.

When the rear cylinder 46 having the suction port 29 and the front cylinder 45 constitute the intake body 12 and the peripheral edge of the second filter 48 is sandwiched between the front cylinder 45 and the rear cylinder 46, the second filter 48 formed of a soft material is formed. It is possible to reliably prevent the intake body 12 from being separated by an external force. Further, since the peripheral edge of the second filter 48 is held by using the front cylinder 45 and the rear cylinder 46, it is not necessary to separately provide a filter mounting structure, and the cost of the blower can be reduced accordingly.

When the second filter 48 is fixed to the cylinder end surface 51 provided on the front cylinder 45, the central receiving frame 49, and the support frame 50, when the external air is sucked toward the blower fan 4, the second filter 48 receives wind pressure. The filter 48 can be held in an appropriate state by preventing the filter 48 from being bent in the ventilation direction. Therefore, the external air sucked from the suction port 29 can be constantly filtered by the second filter 48 in a stable state, and the suction grill 11 and the blower fan 4 on the downstream side of the second filter 48 can be kept in a clean state.

When the pressing ring 68 is mounted around the cylinder end surface 51 of the front cylinder 45, and the rear cylinder 46 is mounted in the rear opening 9, the pressing ring 68 is pressed and fixed by the rear cylinder 46 toward the front cylinder 45. The peripheral edge of the second filter 48 is firmly fixed by the pressing ring 68, and the second filter 48 can be reliably prevented from separating from the front cylinder 45. Further, when the hair dryer is used, the pressing ring 68 can be prevented from floating in the front-rear direction and the radial direction, and can be firmly fixed.

When the front and rear surfaces of the second filter 48 are sandwiched between the central receiving frame 49, the support frame 50, and the rectifying screen 30, the second filter 48 is prevented from flexurally deforming in the front and rear by the three parties, and it is more reliable. Can be held and fixed. Therefore, even when the wind pressure due to the blowing action of the blower fan 4 acts or the vacuum pressure of the vacuum cleaner acts on the second filter 48, the second filter 48 is surely prevented from being greatly deformed and damaged. it can.

When the clearance E is secured between the second filter 48 and the cylinder front end of the rear cylinder 46 with the rear cylinder 46 attached to the rear opening 9, the peripheral edge of the second filter 48 is pressed by the cylinder front end of the rear cylinder 46. It is possible to prevent the stress from being applied to the peripheral edge of the second filter 48 by avoiding the stress. Therefore, it is possible to prevent early damage to the peripheral portion of the second filter 48 that is visible through the suction port 29.

When the control boards 90 and 91 for controlling the operating state of the blower are arranged in the gap space formed between the main body case 1 and the fan case 6, the blowing noise outside the fan case 6 causes the main body case 1 It is possible to improve the quietness of the blower by blocking the radiation outside of the fan by the control boards 90 and 91.

When the front concavo-convex edge 85 and the rear concavo-convex edge 86 are formed on each of the blade leading edge and the blade trailing edge of the fan blade 4a, fan noise when the blower fan 4 is rotationally driven can be reduced. Specifically, when the front concave-convex edge 85 is provided, when air is pushed out by the pressure surface of the fan blade 4a, the pushing reaction force of the air acting on the front edge of the fan blade 4a is dispersed by the concave portion 85a and the convex portion 85b of the front concave-convex edge 85. As a result, it is possible to prevent the blade leading edge from vibrating in the blade thickness direction and generating noise. Further, the timing at which the air flow is pushed out by the pressing surface of the blade leading edge is shifted between the concave portion 85a and the convex portion 85b, and it is possible to prevent the entire blade leading edge from vibrating simultaneously in the blade thickness direction.
Similarly, when the rear concave-convex edge 86 is provided, when the airflow on the pressure surface side and the airflow on the suction surface side merge at the blade trailing edge, they merge earlier in the concave portion 86a and slower in the convex portion 86b. , The two air streams merge gradually. As a result, the post-vortex generated at the blade trailing edge is subdivided, and the velocity loss of the blade wake is reduced. Therefore, the noise due to the vibration of the leading edge of the blade and the noise when the velocity loss of the blade rear flow is large can be suppressed at the same time, and the fan noise can be reduced.

When the adjacent pitch P1 of the concave portions 85a of the front concave-convex edge 85 is set to be larger than the adjacent pitch P2 of the concave portions 86a of the rear concave-convex edge 86, the area of the convex portion 85b of the front concave-convex edge 85 is increased and the structure of the convex portion 85b is increased. Since the strength can be improved, it is possible to more effectively suppress the generation of noise by vibrating the convex portion 85b in the blade thickness direction.

When the uneven depth j1 of the front uneven edge 85 is set to be smaller than the uneven depth j2 of the rear uneven edge 86, the convex portion 85b of the front uneven edge 85 is less likely to bend because the uneven depth j1 is smaller. It is possible to more effectively suppress the generation of noise by vibrating to.

When the curvature radius k1 of the concave portion 85a of the front concave-convex edge 85 is set to be larger than the curvature radius k2 of the concave portion 86a of the rear concave-convex edge 86, the change in the cross section of the convex portion 85b of the front concave-convex edge 85 is made gentle and the structural strength is increased. Therefore, it is possible to further effectively prevent the convex portion 85b of the front concave-convex edge 85 from vibrating in the blade thickness direction and generating noise.

When the fan blade 4a is formed of a fiber reinforced plastic material, the structural strength of the fan blade 4a is improved to make it less likely to vibrate and the fan blade 4a vibrates, as compared with the case where the fan blade 4a is formed of a plastic material only. The fan noise based on can be reduced.

It is a vertical side view of the ventilation structure part of the hair dryer which concerns on this invention. It is a side view of a hair dryer. It is a disassembled rear view which shows the structural member by the side of the suction grill of a hair dryer. It is a partially broken disassembled side view which shows the surrounding structure of a suction grill. It is a vertical side view which shows the detailed structure of an air intake body. It is sectional drawing which shows the mounting structure of a suction grill. It is a partially broken side view showing a mounting structure of a rear cylinder. It is the sectional view on the AA line in FIG. It is a rear view of a ventilation fan. It is an expansion rear view which shows the detailed structure of a fan blade. It is explanatory drawing which shows the related dimension of a ventilation structure part.

(Example) FIGS. 1-11 shows the Example which applied this invention to the hair dryer (blower). The front-rear, left-right, and top-bottom in the present invention follow the cross arrows shown in FIG. In FIG. 2, the hair dryer includes a main body case 1 formed of a hollow cylinder, and a grip 3 that is foldably connected to the main body case 1 about a shaft 2.

1 and 2, the main body case 1 is formed by joining left and right split cases 1a and 1b and an upper case 1c into a hollow cylindrical shape, and a rear opening 9 is provided at a rear end thereof, and a blowout port is provided at a front end thereof. 13 is provided. Inside the main body case 1, there are arranged an axial-flow type blower fan 4 for feeding dry air, a motor 5 for rotationally driving the fan 4, and a round-cylindrical fan case 6 for supporting both of them 4. The heater unit 7 is arranged adjacent to the outlet 6b of the fan case 6. That is, the fan case 6 is arranged in the main body case 1 such that the inlet 6 a and the outlet 6 b thereof are located between the rear opening 9 of the main body case 1 and the air outlet 13. As shown in FIG. 1, a screw boss 26 is provided on the lower surface of the tubular wall of the fan case 6, and the screw boss 26 is fastened to the left split case 1b with a screw 27, so that the fan case 6 is separated from the main body case. It is fixed at 1. The left and right split cases 1a and 1b are fastened and fixed with screws (not shown).

The blower fan 4 integrally includes four fan blades 4a and a fan boss 4b. A plurality of flow straightening vanes 15 are provided on the outlet 6b side of the fan case 6, and a motor holder 16 is provided at the center thereof. The motor 5 is attached to the holder 16, and the blower fan 4 is fixed to the output shaft protruding from the rear end of the holder 16. That is, the motor 5 and the blower fan 4 are supported by the fan case 6 via the motor holder 16 and the rectifying blades 15. The air flow pressurized and twisted by the blower fan 4 is straightened by the straightening vanes 15 into a linear flow, and then fed toward the heater unit 7. On the front surface of the grip 3, there is provided a switch knob 8 for starting the motor 5 or switching the power supply state to the heater unit 7. Further, on the rear surface of the grip 3, there is provided an air volume switching knob 10 for switching the rotational speed of the motor 5 to switch the air volume of the blower fan 4 between large and small. In FIG. 1, between the inlet 6 a of the fan case 6 and the rear opening 9 of the main body case 1, a suction grill 11 that covers the inlet 6 a of the fan case 6 and a cylindrical air intake body 12 are arranged. An outlet nozzle 14 is attached to the outlet 13 of the main body case 1 (see FIG. 2).

In the hair dryer configured as described above, in order to significantly suppress the noise when the blower fan 4 is driven and reduce the overall noise when the blower fan 4 is used, suction is performed between the blower fan 4 and the rear opening 9. The grill 11 and the air intake body 12 are arranged in the order described. As shown in FIGS. 3 and 4, the suction grill 11 includes a ventilation screen 23 having a partially spherical shape (inwardly curved concave shape) that bulges toward the blower fan 4, and a mounting portion 24 that extends to the periphery of the ventilation screen 23. It is equipped with. The suction grill 11 is formed by punching a metal-made blank made of an aluminum plate, a thin steel plate, a stainless thin plate, etc., into a tea strainer net-like shape by pressing, and forming a group of ventilation holes 25 in the ventilation screen 23. I am doing it. In this embodiment, the ventilation hole 25 is formed only on the side of the inner concave curved surface of the ventilation screen 23, and the ventilation hole 25 is formed in the flange-shaped mounting portion 24 or the boundary portion between the inner concave curved surface and the mounting portion 24. Although the formation is avoided (see FIG. 5 ), the mounting portion 24 may be provided with the ventilation hole 25.

The air intake body 12 is composed of a front cylinder 45 and a rear cylinder 46 each made of a plastic molded product, and the rear cylinder 46 is provided with a suction port 29. Further, a rectifying screen 30 also serving as the first filter 47 and a second filter 48 are arranged in the adjacent portion of the front cylinder 45 and the rear cylinder 46 facing the suction port 29. The front cylinder 45 is composed of a round cylinder whose front and rear are open, and the diameter of the cylinder wall is set to be gradually larger toward the fan case 6, and the cylinder wall extending from the inlet to the outlet (outlet) 31 is gently curved. It is configured as an expanded cylindrical wall (cylindrical wall) 32.

A frame structure for receiving the second filter 48 is provided adjacent to the rear cylinder 46 of the front cylinder 45. As shown in FIG. 3, the frame structure includes a circular center receiving frame 49 and an X-shaped support frame 50 that supports the frame 49. The center receiving frame 49 and the support frame 50 are the end face 51 of the front cylinder 45 and the cylinder end face 51. It is provided flush. The air intake body 12 has a function of reducing turbulent noise by the rectification effect of the front cylinder 45 and a function of preventing hair, dust, and the like from being sucked into the fan case 6 by the rectification screen 30 and the second filter 48. Demonstrate at the same time. The rectifying screen 30 preferably has a rectifying effect, but may have a protective structure that can simply prevent invasion of hair or fingers.

The second filter 48 is formed of a flexible sheet-shaped soft material. More specifically, it is formed of a commercially available resin mesh in which thin plastic wires are crossed, and it has a group of ventilation holes 48a that are sufficiently smaller than the first filter 47, so that hair and small dust can be removed from the fan case 6. Prevent it from getting inside. As shown in FIG. 5, the second filter 48 is heat-molded into a shallow dish shape, and its end face is heat-welded to the central receiving frame 49, the support frame 50, and the cylinder end face 51 to be integrated with the front cylinder 45. .. When the air intake body 12 is attached to the rear opening 9 of the main body case 1, the front and rear surfaces of the second filter 48 are firmly sandwiched between the central receiving frame 49 and the supporting frame 50 made of plastic and the rectifying screen 30. That is, the second filter 48 formed of a flexible sheet-shaped soft material is securely sandwiched between the center receiving frame 49 and the support frame 50, which are harder than the filter 48, and the rectifying screen 30. Therefore, even when the wind pressure due to the blowing action of the blower fan 4 acts or the vacuum pressure of the vacuum cleaner acts on the second filter 48, it is possible to prevent the second filter 48 from being greatly deformed and damaged.

As shown in FIG. 7, the rear cylinder 46 integrally includes a double cylinder-shaped cylinder main portion 53 and cover walls 54 and 55 extending above and below the cylinder main portion 53. Has a bell mouth-shaped suction port 29. As described above, by forming the suction port 29 in a bell mouth shape, the flow of the air sucked into the air intake body 12 can be made smooth and the silent effect can be enhanced. The suction port 29 and the expanding cylindrical wall 32 are smoothly continuous with each other and have a gentle S-shaped cross section. The straightening screen 30 is integrally formed at the end of the rear cylinder 46 adjacent to the front cylinder 45. As shown in FIG. 3, the rectifying screen 30 is composed of quadruple round rectifying ribs 56 arranged concentrically and X-shaped crossing ribs 57 that support each rectifying rib 56.

In order to improve the noise reduction effect while improving the rectification effect by the suction port 29, as shown in FIG. 5, the thickness T of the ventilation screen 23 of the suction grille 11 is set smaller than the rib length L1 of the rectification rib 56 in the ventilation direction. doing. In addition, the rib thickness L2 of the rectifying rib 56 is set to the length of the rectifying rib 56 in the ventilation direction in order to prevent the suction port 29 from being blocked and the ventilation resistance from increasing while ensuring the rectifying effect. It is set smaller than L1.

Next, a structure for fixing the suction grille 11 to the fan case 6, a connecting structure for the front cylinder 45 and the fan case 6, a connecting structure for the front cylinder 45 and the rear cylinder 46, a mounting structure for the rear opening 9 of the rear cylinder 46, and the like. Will be explained.
As shown in FIGS. 5 and 6, the mounting portion 24 of the suction grille 11 includes an inner engagement wall 60 at the peripheral edge of the ventilation screen 23 and an outer engagement that is bent in an L-shape continuously from the inner engagement wall 60. The wall 61 is formed in a multi-cylinder shape. Further, engaging claws 62 are integrally provided at four locations around the outer engaging wall 61, and engaging ribs 63 for engaging the engaging claws 62 are formed in a circular shape on the outer peripheral surface of the fan case 6. It is protruding. By fitting the outer engaging wall 61 onto the peripheral surface of the inlet 6a of the fan case 6 and engaging the engaging claws 62 with the engaging ribs 63, the suction grill 11 cannot be separated from the fan case 6. Moreover, they can be integrated so that they cannot move relative to each other. Since the inner engagement wall 60 and the outer engagement wall 61 in this state sandwich the tubular wall of the fan case 6 inside and outside, the suction grill 11 can be fixed to the fan case 6 in a state in which it cannot move in the radial direction. The structural strength of the fan case 6 can be enhanced by the outer engagement wall 61 that is in close contact with the peripheral surface of the case, and the fan case 6 that receives the vibration of the motor 5 can be prevented from generating vibration noise. As shown in FIG. 6, after the outer engagement wall 61 is attached to the fan case 6, the engagement claw 62 is bent at the tip of the claw to engage with the engagement rib 63.

As shown in FIG. 4, four quadrangular connecting claws 64 are provided so as to project forward on the peripheral surface of the front cylinder 45 adjacent to the fan case 6. A connection hole 65 is formed. Further, connecting protrusions 66 that engage with the connecting holes 65 are formed at four locations on the peripheral surface of the fan case 6. After the mounting portion 24 of the suction grill 11 is mounted on the fan case 6, the connecting claw 64 of the front cylinder 45 is applied to the peripheral surface of the fan case 6, and the connecting hole 65 is press-fitted and engaged with the connecting protrusion 66. The front cylinder 45 can be fixed to the fan case 6. In this mounted state, the cylinder end surface of the delivery port 31 of the front cylinder 45 cooperates with the fan case 6 to clamp and fix the mounting portion 24 of the suction grill 11, so that the suction grill 11 can be further firmly fixed. As can be understood from the above description, the suction grill 11 and the front cylinder 45 are fixed to the fan case 6 inseparably.

As shown in FIG. 5, a pressing ring 68 is provided in the adjacent portion of the front cylinder 45 and the rear cylinder 46. The pressing ring 68 integrally includes a cylindrical wall 69 that covers the peripheral edge of the second filter 48 and a connecting seat 70 that receives the front end of the suction port 29 of the rear cylinder 46. In order to temporarily fix the pressing ring 68 to the front cylinder 45, engagement holes 71 are formed at four positions on the cylinder wall 69, and ribs 72 corresponding to the engagement holes 71 are provided on the peripheral surface of the front cylinder 45. ing. The pressing ring 68 can be temporarily fixed to the front cylinder 45 by externally fitting the pressing ring 68 to the front cylinder 45 and dropping the ribs 72 into the engagement holes 71 to engage them. In this state, by mounting the rear cylinder 46 in the rear opening 9 of the main body case 1, the pressing ring 68 is pressed and fixed by the rear cylinder 46 toward the front cylinder 45. Therefore, when the hair dryer is used, the pressing ring 68 can be prevented from floating in the front-rear direction and the radial direction, and can be firmly fixed. Further, the second filter 48 fixed to the front cylinder 45 can be firmly fixed by the pressing ring 68, and the second filter 48 can be reliably prevented from separating from the front cylinder 45.

When the pressing ring 68 is pressed and fixed by the rear cylinder 46, a gap E is secured between the second filter 48 and the cylinder front end of the rear cylinder 46. In this way, when the gap E is formed between the second filter 48 and the rear cylinder 46, even if the pressing ring 68 is pressed and fixed to the cylinder end surface 51, the peripheral edge of the second filter 48 is rearward. It is possible to avoid being pressed by the tube end of the tube 46 and to prevent stress from being applied to the peripheral edge of the second filter 48. Therefore, it is possible to prevent early damage to the peripheral portion of the second filter 48 that is visible through the suction port 29.

As shown in FIG. 7, in order to detachably mount the rear cylinder 46 in the rear opening 9, the main cylinder portion 53 of the rear cylinder 46 and the upper and lower cover walls 54 and 55 are provided along the periphery of the tripartites 53 to 55. Positioning ribs 74 are formed. Further, a latching claw 75 is formed at the left-right center of the upper end of the upper cover wall 54, and a fastening piece 76 is formed at the left-right center of the lower end of the lower cover wall 55. Further, a pair of left and right engaging claws 77 are formed in the center of the cylinder main portion 53 in the vertical direction. On the side of the rear opening 9, a positioning groove 78 corresponding to the positioning rib 74 is formed along the peripheral edge thereof, and a hooking groove 79 for engaging the hooking claw 75 is formed in the left-right center of the upper case 1c, A screw seat 80 is formed at the lower end of the left split case 1a. Further, an engaging stepped portion 81 corresponding to the engaging claw 77 is formed at the vertical center of the left and right split cases 1a and 1b.

As shown in FIG. 8, the engaging claws 75 are engaged with the engaging grooves 79, and the positioning ribs 74 are engaged with the positioning grooves 78. By doing so, the rear cylinder 46 can be attached to the rear opening 9 to close the rear surface of the main body case 1. In this state, the fastening piece 76 is inserted into the inner surface of the rear opening 9 and vertically faces the screw seat 80. Therefore, by screwing the screw (disc screw) 82 inserted into the screw seat 80 into the fastening piece 76, The rear cylinder 46 can be fixed to the main body case 1. By loosening the screws 82 as necessary and removing the rear cylinder 46 from the rear opening 9, the rear cylinder 46 and the pressing ring 68 can be washed and washed, and the dust and the like adhering to the second filter 48 can be removed. As described above, in the state where the air intake body 12 is mounted on the main body case 1, most of the portion projects rearward from the rear opening 9, and the rear opening 9 is closed by the rear cylinder 46. The mounting portion 24 of the suction grill 11 is located in front of the front end of the cylinder of the air intake body 12.

The fan blade 4a is configured as follows in order to suppress the blade noise caused by the vortex and separation generated by the fan blade 4a of the blower fan 4 or the vibration of the fan blade 4a. As shown in FIGS. 9 and 10, a front uneven edge 85 is provided on the blade front edge on the lower side in the rotation direction of the fan blade 4a, and a rear uneven edge 86 is formed on the blade rear edge on the upper side in the rotation direction of the fan blade 4a. .. The arrow in FIG. 9 indicates the rotation direction of the blower fan 4. The front concave-convex edge 85 is formed by a concave portion 85a and a convex portion 85b which are gently curved, and the rear concave-convex edge 86 is formed by a concave portion 86a and a convex portion 86b in which the number of concaves and convexes is larger than the front concave-convex edge 85. Further, the entire blower fan 4 is formed of a fiber reinforced plastic material to improve the structural strength of the fan blade 4a and make it difficult to vibrate. As the reinforcing fiber, glass fiber, carbon fiber, boron fiber, aromatic polyamide resin fiber or the like can be applied.

In this way, when the front concave-convex edge 85 is formed in a corrugated shape with the plurality of concave portions 85a and the convex portions 85b, when air is pushed out by the pressure surface of the fan blade 4a (the side facing the straightening vanes 15), the blade front The pushing reaction force of air acting on the edge can be dispersed to prevent the blade leading edge from vibrating in the blade thickness direction and generating noise. Further, since the concave portion 85a and the convex portion 85b are displaced at the timing when the air flow is pushed out by the pressing surface of the blade leading edge, there is also an effect that the entire blade leading edge can be suppressed from vibrating in the blade thickness direction at the same time. ..
Similarly, when the rear concave-convex edge 86 is formed by a plurality of concave portions 86a and convex portions 86b, the air flow on the pressure surface side and the air flow on the negative pressure surface (the side facing the suction grill 11) side merge at the blade trailing edge. At this time, merging occurs earlier in the concave portion 86a, and merging occurs later in the convex portion 86b, so that the two air streams merge gradually. As a result, the post-vortex generated at the blade trailing edge is subdivided, and the velocity loss of the blade wake is reduced. Therefore, the noise due to the vibration of the leading edge of the blade and the noise when the velocity loss of the blade wake is large can be suppressed at the same time, and the fan noise can be reduced.

In order to make the vibration regulation effect by the front concave-convex edge 85 and the sub-vortex subdivision effect by the rear concave-convex edge 86 more reliable, the relational dimensions of the front concave-convex edge 85 and the rear concave-convex edge 86 are set as follows. As shown in FIG. 10, the adjacent pitch P1 of the concave portions 85a of the front concave-convex edge 85 is set to be larger than the adjacent pitch P2 of the concave portions 86a of the rear concave-convex edge 86. Further, the uneven depth j1 of the front uneven edge 85 is set to be smaller than the uneven depth j2 of the rear uneven edge 86. Further, the curvature radius k1 of the recess 85a of the front concave-convex edge 85 is set larger than the curvature radius k2 of the recess 86a of the rear concave-convex edge 86.

When the adjacent pitch P1 of the concave portions 85a of the front concave-convex edge 85 is set to be larger than the adjacent pitch P2 of the concave portions 86a of the rear concave-convex edge 86, the area of the convex portion 85b of the front concave-convex edge 85 is increased and the structure of the convex portion 85b is increased. Strength can be improved. Along with this, it is possible to more effectively suppress the generation of noise by vibrating the convex portion 85b in the blade thickness direction.
When the uneven depth j1 of the front uneven edge 85 is set to be smaller than the uneven depth j2 of the rear uneven edge 86, the convex portion 85b of the front uneven edge 85 is less likely to bend because the uneven depth j1 is smaller. It is possible to more effectively suppress the generation of noise by vibrating to. Further, the curvature radius k1 of the concave portion 85a of the front concave-convex edge 85 is set to be larger than the curvature radius k2 of the concave portion 86a of the rear concave-convex edge 86 for the same reason.

As described above, by measuring the blowing noise of the blower fan 4 in which the front concavo-convex edge 85 and the rear concavo-convex edge 86 are formed on the fan blade 4a and comparing it with the blowing noise of the blowing fan of the conventional structure, It was confirmed whether it could be reduced to some extent. Specifically, prepare a hair dryer for measurement in which a suction grill with a curved outer protrusion is attached to the rear end of the main body case, and assemble a conventional blower fan in which the front uneven edge 85 and the rear uneven edge 86 are not formed. The blowing noise was measured in detail, the blowing fan 4 according to the present invention was replaced, and the blowing noise was measured to compare the blowing noises of both. Regarding the measurement of blast noise, a microphone of a sound level meter was arranged at a position 1 m away from the rear end of the main body case 1, and the rotation speeds of both microphones were the same to measure the noise level. As a result, it was confirmed that the hair dryer incorporating the blower fan 4 according to the present invention can significantly reduce the blower noise as compared with the blower noise of the hair dryer incorporating the blower fan having the conventional structure.

As described above, the main body case 1 is configured by joining the left and right split cases 1a and 1b and the upper case 1c into a hollow cylindrical shape. As shown in FIG. 1, the upper case 1c and the fan case 6 are A large gap is formed between the fan case 6 and the lower part of the left and right divided cases 1a and 1b. Utilizing these gaps, the power supply-control board (control board) 90 is arranged in the lower clearance, and the temperature control board (control board) 91 is arranged in the upper clearance. Further, the mode control switch 92 is mounted on the temperature control board 91 so that the switch 92 can be switched by the push button 93 provided on the upper surface of the upper case 1c. As shown in FIG. 2, a discharge electrode 94 for ion generation is provided above the heater unit 7. As described above, by arranging the control boards 90 and 91 in the gap space between the main body case 1 and the fan case 6, the ventilation noise outside the fan case 6 is dissipated to the outside of the main body case 1. The noise can be improved by shielding the noise with the control boards 90 and 91.

When the switch knob 8 is turned on, a commercial alternating current is supplied to the power supply-control board 90 to adjust the current for operating the motor 5, the heater unit 7, the discharge electrode 94 and the like. Further, the power supply/control board 90 switches the driving rotation speed of the motor 5 between large and small in response to an on/off signal of the air volume switching knob 10. When the push button 93 is operated and the mode changeover switch 92 is turned on, the heat generation amount of the heater unit 7 is maximized, and the warm air of 100° C. can be blown out from the air outlet 13. Hereinafter, every time the push button 93 is turned on, hot air of 80° C. and 60° C. can be sent out from the outlet 13, and when the push button 93 is turned on again, the power supply to the heater unit 7 is cut off and the temperature is kept at room temperature. Of dry air is sent out from the outlet 13. After that, the same temperature control is repeated.

According to the hair dryer configured as described above, the airflow sucked from the suction port 29 by the blower fan 4 during use is rectified while passing through the rectifying screen 30, the second filter 48, and the expanding cylindrical wall 32. And flows toward the suction grill 11. At this time, the airflow that has passed through the expanding cylindrical wall 32 is sucked into the blower fan 4 while being straightened again by the ventilation screen 23, but most of the sucked airflow is forward and backward with respect to the rotation region of the fan blade 4a. The air is sucked in from the peripheral portion of the ventilation screen 23 that faces it. This is because the negative pressure is higher in the portion of the fan blade 4a facing the rotation region, and the negative pressure is smaller in the portion directly facing the fan boss 4b in the front-rear direction.

However, the adjoining distance between the curved top 40 of the ventilation screen 23 and the fan boss 4b is sufficiently smaller than the other screen portions. Therefore, there is no room for the airflow reaching the vicinity of the curved top 40 to stay between the curved top 40 and the fan boss 4b. Therefore, the generation of eddy currents due to the retention of the airflow is prevented and turbulent noise is generated. Can be greatly reduced. Further, near the hypotenuse of the trapezoidal fan boss 4b, a flow of air (radiant airflow) that is dragged in the radial direction toward the rotation region of the fan blade 4a is formed. Due to this radiant airflow, the air between the curved top 40 and the fan boss 4b is smoothly sent to the rotating region of the fan blade 4a, and the air flow stays between the fan boss 4b and the curved top 40 to generate a vortex. It helps to eliminate the problem. As described above, the suction grille 11 is provided to reduce the generation of turbulent noise due to the retention of the air flow.

In addition to the above noise reduction structure, in order to further effectively reduce turbulent noise, in the hair dryer according to the embodiment, the relational dimensions of the blower fan 4, the suction grill 11 and the intake body 12 are as follows. Set to.
As shown in FIG. 11, the facing interval between the curved top 40 of the ventilation screen 23 of the suction grill 11 and the fan boss 4b of the blower fan 4 is set to a, and the distance from the mounting portion 24 of the suction grill 11 to the curved top 40 of the ventilation screen 23 is set to a. When the front-rear distance is b, the suction grill 11 is arranged so that the facing distance a and the front-rear distance b satisfy the inequality (a<b).

When the front-rear distance b is set to be larger than the facing distance a as described above, the formation of a retention space where turbulent noise is likely to occur between the ventilation screen 23 and the fan boss 4b is eliminated, and the ventilation with an indented shape The degree of curvature of the screen 23 can be increased. Further, as the bending degree of the ventilation screen 23 increases, the area of the peripheral portion of the ventilation screen 23 that faces the region where the flow velocity of the air flow is large increases, so that the passage amount of the air flow in the center of the ventilation screen 23 can be reduced. Therefore, it is possible to prevent the air flow from staying in the space between the ventilation screen 23 and the fan boss 4b and generate a vortex flow, thereby reliably preventing turbulent noise. For this reason, the suction grill 11 is arranged so as to satisfy the inequality (a<b).

By the way, when the radius of curvature of the ventilation screen 23 is large, the degree of curvature becomes small, and the area of the peripheral portion of the ventilation screen 23 facing the region where the flow velocity of the air flow is large becomes small. Will increase. In the above embodiment, the front-rear distance b is set to about 5 times the facing distance a so that the area of the peripheral portion of the ventilation screen 23 facing the region where the flow velocity of the air flow is large is sufficiently large.

The front-rear distance from the mounting portion 24 of the suction grille 11 to the curved top 40 of the ventilation screen 23 is defined as b, and the front-rear distance from the opening surface of the suction port 29 of the intake body 12 to the ventilation hole 25 of the ventilation screen 23 of the suction grille 11 is defined. The suction grille 11 is arranged so that the front-rear distance b and the front-rear distance e satisfy the inequality (b<e).

As described above, when the front-rear distance e is set to be larger than the front-rear distance b, the air flow that is sucked from the suction port 29 and reaches the ventilation screen 23 is rectified by the front cylinder 45, the suction port 29, and the rectification screen 30, It is possible to suppress the generation of turbulent flow inside the cylinder 45. Further, the rotation noise of the blower fan 4 and the blade noise of the fan blades 4a can be attenuated by the expanding cylindrical wall 32. Therefore, in addition to the effect of suppressing the turbulent flow noise by the ventilation screen 23, the noise of the hair dryer can be reduced by the noise reduction effect of the front cylinder 46.

When the front-rear distance from the opening surface of the suction port 29 of the air intake body 12 to the mounting portion 24 of the suction grill 11 is d, and the facing distance between the mounting portion 24 of the suction grill 11 and the fan blade 4a of the blower fan 4 is c. The suction grille 11 is arranged so that the front-rear distance d and the facing distance c satisfy the inequality (c<d). In FIG. 11, reference numeral f indicates the front-rear dimension from the rear end of the suction port 29 of the rear cylinder 46 to the mounting portion 24 of the suction grill 11.

As described above, when the front-rear distance d is set to be larger than the facing distance c, the air flow that is sucked from the suction port 29 and reaches the blade edge of the fan blade 4a is divided into three parts: the straightening screen 30, the front cylinder 45, and the ventilation screen 23. It is possible to suppress the generation of turbulent flow inside the air intake body 12 and inside the fan case 6 facing the ventilation screen 23 by rectifying. Further, the rotation noise of the blower fan 4 and the blade noise of the fan blade 4a can be attenuated by the ventilation screen 23 and the air intake body 12. Therefore, in addition to the effect of suppressing turbulent noise and the noise damping effect of the ventilation screen 23, the noise damping effect of the air intake body 12 can reduce the overall noise of the hair dryer.

When the opening area of the suction port 29 of the intake body 12 is C and the opening area of the delivery port 31 is D, the opening area C and the opening area D are set to satisfy the inequality (C<D). As described above, when the opening area D of the outlet 31 is set to be larger than the opening area C, the rotation noise of the blower fan 4 and the blade noise of the fan blade 4a that have passed through the ventilation screen 23 are directed toward the suction port 29. It is possible to reduce the amount of noise emitted from the suction port 29 and further reduce the overall noise of the hair dryer by sealing off the leaks with the suction port 29 having a small opening area. Further, the flow velocity of the air flow immediately before flowing into the ventilation screen 23 from the delivery port 31 is reduced to suppress the generation of a vortex near the passing air flow after passing through the ventilation holes 25 of the ventilation screen 23, To that extent, the overall noise of the hair dryer can be reduced.

Although the rear cylinder 46 of the air intake body 12 is detachably attached to the main body case 1 in the above embodiment, it is not necessary to attach the rear cylinder 46 to the main body case 1 and the rear cylinder 46 is attached to the main body case 1 only in a fixed state. Good. The suction grill 11 does not need to be formed of a metal plate, but can be formed of a plastic molded product. In that case, the engaging claw 62 may be formed in a hook shape and engaged with the engaging rib 63 while elastically deforming the engaging claw 62. The ventilation screen 23 does not need to have an inwardly curved shape formed of one curved surface, and can be formed by a curved surface formed by stacking a plurality of curved surfaces in a multi-step manner. If necessary, the cross section of the ventilation screen 23 may be a curved surface bent in a corrugated shape. The second filter 48 does not need to be heat-welded to the central receiving frame 49, the support frame 50, and the tube end surface 51, but may be fixed by adhesion with an adhesive.

INDUSTRIAL APPLICABILITY The present invention can be widely applied to a blower equipped with a suction grill such as a curl dryer or a circulator in addition to a hair dryer.

1 Main Body Case 4 Blower Fan 5 Motor 6 Fan Case 9 Rear Opening 11 Suction Grille 12 Air Intake Body 23 11 Ventilation Screen 24 11 Mounting Part 25 23 Vent Hole 29 Suction Port 30 Rectifying Screen 45 Front Tube 46 Rear Tube 48 Filter 53 Main cylinder part 54/55 Cover wall 60 Inner engagement wall 61 Outer engagement wall 68 Presser ring 85 Front uneven edge 86 Rear uneven edge

Claims (14)

A fan case (which supports a motor (5) and a blower fan (4) inside a main body case (1) having a rear opening (9) and an outlet (13) and covers at least the periphery of the blower fan (4). A blower device in which 6) is arranged,
The fan case (6) is located inside the main body case (1) with its inlet (6a) and outlet (6b) located between the rear opening (9) and the outlet (13) of the main body case (1). Has been placed,
At the inlet (6a) of the fan case (6), a suction grill (11) covering the inlet (6a) is arranged.
The suction grille (11) includes a ventilation screen (23) and a mounting portion (24) provided on the periphery of the ventilation screen (23),
The ventilation screen (23) expands from the inlet (6a) of the fan case (6) toward the blower fan (4) in a state where the mounting portion (24) is mounted and fixed to the inlet (6a) of the fan case (6). Ri Oh so issued,
An air intake body (12) having a suction port (29) is attached to a rear opening (9) of the main body case (1),
The air intake body (12) includes a cylindrical wall (32) for guiding the air flowing in from the suction port (29) toward the ventilation screen (23),
An air blower characterized in that a rectifying screen (30) also serving as a first filter (47) is arranged facing the suction port (29) of the air intake body (12) . 2. The blower device according to claim 1, wherein the straightening screen (30) includes a plurality of concentric straightening ribs (56) and cross ribs (57) supporting the plurality of straightening ribs (56) . Each of the suction port (29) and the delivery port (31) of the air intake body (12) is formed in a tubular shape, and an expanded tubular wall (32) having a gently curved cross section between the two (29, 31) is formed. The air blower according to claim 1 or 2, which is continuous . With the intake body (12) attached to the rear opening (9) of the main body case (1), the cylinder front end of the delivery port (31) cooperates with the fan case (6) to attach the suction grille (11) ( The air blower according to any one of claims 1 to 3, which sandwiches 24) . The blower according to claim 2, wherein the thickness (T) of the ventilation screen (23) of the suction grille (11) is set to be smaller than the rib length (L1) of the flow regulating ribs (56) in the ventilation direction . The blower according to claim 2 or 5, wherein a rib thickness (L2) of the rectifying rib (56) is set to be smaller than a rib length (L1) of the rectifying rib (56) in a ventilation direction . A second filter (48) having a mesh structure having a group of ventilation holes (48a) smaller than the first filter (47) is disposed on the side of the flow control screen (30) facing the suction grille (11). The air blower according to any one of claims 1 to 6 . The second filter (48) is made of a flexible sheet-shaped flexible material, and the rectifying screen (30) is made of a harder material than the second filter (48).
The air blower according to claim 7, wherein the second filter (48) and the rectifying screen (30) are arranged adjacent to each other . The intake body (12) is composed of a front cylinder (45) having a cylinder wall (32) and a rear cylinder (46) having a suction port (29),
The blower according to claim 7 or 8, wherein the peripheral edge of the second filter (48) is sandwiched between the front cylinder (45) and the rear cylinder (46) . A center receiving frame (49) and a support frame (50) for supporting the same frame (49) are provided on the cylinder end surface (51) of the front cylinder (45) adjacent to the rear cylinder (46) and the cylinder end surface (51). It is provided in the state of becoming one,
The blower according to claim 9, wherein the second filter (48) is fixed to the tube end surface (51), the central receiving frame (49), and the supporting frame (50) . A press ring (68) having a cylinder wall (69) covering the peripheral edge of the second filter (48) is arranged around the cylinder end surface (51) of the front cylinder (45),
The rear cylinder (46) is attached to the rear opening (9) of the main body case (1),
With the rear cylinder (46) mounted in the rear opening (9), the presser ring (68) mounted around the cylinder end surface (51) of the front cylinder (45) is attached to the front cylinder (45) of the rear cylinder (46). ) towards the presses fixed blowing device according to claim 10 Ru tare.
With the rear cylinder (46) attached to the rear opening (9), the front and rear surfaces of the second filter (48) are sandwiched between the central receiving frame (49) and the supporting frame (50) and the rectifying screen (30). The air blower according to claim 10 . 13. A gap (E) is secured between the second filter (48) and the front end of the rear cylinder (46) when the rear cylinder (46) is attached to the rear opening (9). Blower according to any one of . The air blower according to any one of claims 1 to 13, wherein the ventilation screen (23) of the suction grille (11) is bulged toward the blower fan (4) in an inwardly curved shape .

Images