Blower device

Abstract

To provide a blower device capable of suppressing deterioration in air blowing performance, while achieving reduction in noise.SOLUTION: In a blower device 1, a centrifugal blower 3 in which a suction hole 34 is formed is provided inside a housing 2. The suction hole 34 is positioned at a position being separated from an air supply port 21 in a reference direction set at a noise absorption member 4. On a noise absorption exposure surface 40 of the noise absorption member 4, a noise absorption upper end part 40a is formed in a cross section irregular shape section S. At least a part of the noise absorption upper end part 40a is opposed to the suction hole 34. In the cross section irregular shape section S, on the cross section of the noise absorption member 4 on a flat surface orthogonal to the reference direction, a thickness of the noise absorption member 4 at a position of the noise absorption upper end part 40a is thicker than a thickness of the noise absorption member 4 at a position deviated from the noise absorption upper end part 40a.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a blower device.

Background Art

[0002] Patent Document 1 discloses a blower device configured to reduce noise by providing a sound-absorbing member on the inner surface of a box incorporating a centrifugal blower.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional blower device disclosed in Patent Document 1, the thickness of the sound-absorbing member is constant at any position of the sound-absorbing member. For this reason, if the thickness of the sound-absorbing member is increased to further reduce the noise of the blower device, the air passage of the airflow generated by the centrifugal blower becomes narrow. As a result, the blowing performance of the blower device deteriorates.

[0005] The present disclosure solves the above problems, and an object thereof is to provide a blower device capable of suppressing a decrease in blowing performance while reducing noise.

Means for Solving the Problems

[0006] The air blower according to the present disclosure includes a housing in which an air supply port and an exhaust port are formed, a centrifugal blower provided inside the housing and having an intake hole formed therein, and a sound-absorbing member provided on the inner surface of the housing. The centrifugal blower generates an air flow that flows from the air supply port through the intake hole to the exhaust port. Inside the housing, an air passage in the housing for guiding the air flow from the air supply port to the intake hole is formed. In the sound-absorbing member, a reference direction along the inner surface of the housing and a cross-sectionally deformed section that is a specific section in the reference direction are set. The intake hole is located at a position away from the air supply port in the reference direction. In the sound-absorbing member, a sound-absorbing exposed surface exposed to the air passage in the housing is formed. On the sound-absorbing exposed surface, a sound-absorbing upper end portion located in the cross-sectionally deformed section is formed. At least a part of the sound-absorbing upper end portion faces the intake hole. In the cross-sectionally deformed section, in the cross-section of the sound-absorbing member in a plane perpendicular to the reference direction, the thickness of the sound-absorbing member at the position of the sound-absorbing upper end portion is thicker than the thickness of the sound-absorbing member at a position deviated from the sound-absorbing upper end portion.

Effect of the Invention

[0007] According to the present disclosure, it is possible to suppress a decrease in the air blowing performance while reducing noise.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0009] Embodiments for carrying out the subject matter of the present disclosure will be described with reference to the accompanying drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and overlapping descriptions are appropriately simplified or omitted. Note that the subject matter of the present disclosure is not limited to the following embodiments, and within the scope not departing from the gist of the present disclosure, deformation of any component of the embodiment or omission of any component of the embodiment is possible.

[0010] Embodiment 1. FIG. 1 is a perspective view showing the blower according to Embodiment 1. FIG. 2 is a schematic configuration diagram showing the blower of FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2. In the figure, the blower 1 is suspended from the ceiling of the room by a plurality of suspension rods (not shown). Thereby, the blower 1 is exposed to the indoor space. The blower 1 has a housing 2, a centrifugal blower 3, and a sound-absorbing member 4.

[0011] An axis is set in the housing 2. Here, in the housing 2, the direction along the axis of the housing 2 is the axial direction X, a specific direction orthogonal to the axial direction X is the lateral direction Y, and the direction orthogonal to both the axial direction X and the lateral direction Y is the vertical direction Z. The blower 1 is arranged with the vertical direction Z of the housing 2 coinciding with the vertical direction.

[0012] The housing 2 has an air supply side end wall 2a, an exhaust side end wall 2b, a first side wall 2c, a second side wall 2d, a third side wall 2e, and a fourth side wall 2f. The air supply side end wall 2a and the exhaust side end wall 2b face each other in the axial direction X of the housing 2. The first side wall 2c and the second side wall 2d face each other in the lateral direction Y of the housing 2. The third side wall 2e and the fourth side wall 2f face each other in the longitudinal direction Z of the housing 2. The shape of the housing 2 is a rectangular parallelepiped by the air supply side end wall 2a, the exhaust side end wall 2b, the first side wall 2c, the second side wall 2d, the third side wall 2e, and the fourth side wall 2f.

[0013] An air supply port 21 and an exhaust port 22 are formed in the housing 2. The air supply port 21 is formed in the air supply side end wall 2a. The exhaust port 22 is formed in the exhaust side end wall 2b. An air supply duct (not shown) existing in the indoor space is connected to the air supply port 21. An exhaust duct (not shown) reaching the outside is connected to the exhaust port 22.

[0014] The centrifugal blower 3 is provided inside the housing 2. The centrifugal blower 3 generates an air flow. The air flow generated by the centrifugal blower 3 flows from the indoor space, through the air supply duct, the inside of the housing 2, and the exhaust duct, to the outside. The centrifugal blower 3 has a scroll casing 31, a fan 32, and a motor 33.

[0015] The scroll casing 31 is fixed to the exhaust side end wall 2b. An intake hole 34 is formed in the scroll casing 31. The scroll casing 31 is arranged with the intake hole 34 facing in a direction different from each of the air supply port 21 and the exhaust port 22. In the present embodiment, the scroll casing 31 is arranged inside the housing 2 with the intake hole 34 facing in a direction orthogonal to the direction in which each of the air supply port 21 and the exhaust port 22 faces. Specifically, the scroll casing 31 is arranged inside the housing 2 with the intake hole 34 facing the first side wall 2c. Therefore, in the present embodiment, the direction along the axis of the intake hole 34 coincides with the lateral direction Y of the housing 2.

[0016] The scroll casing 31 is formed with a suction hole forming surface 31a. The suction hole forming surface 31a is exposed to the space inside the housing 2 while facing the first side wall 2c. The suction hole forming surface 31a is orthogonal to the lateral direction Y of the housing 2. The suction hole 34 is formed in the suction hole forming surface 31a of the scroll casing 31.

[0017] The motor 33 is provided on the scroll casing 31. A part of the motor 33 is located inside the scroll casing 31. The axis of the motor 33 coincides with the axis of the suction hole 34. Therefore, the motor 33 is arranged inside the housing 2 with the axial direction of the motor 33 coinciding with the lateral direction Y of the housing 2.

[0018] The fan 32 is provided inside the scroll casing 31. The fan 32 is attached to the motor 33. The fan 32 rotates about the axis of the motor 33 by the driving force of the motor 33. The fan 32 generates an air flow by rotating. That is, the centrifugal blower 3 generates an air flow by rotating the fan 32 by the driving force of the motor 33.

[0019] The air flow generated by the rotation of the fan 32 flows into the inside of the housing 2 through the air supply port 21 from the air supply duct. The air flow that has flowed into the inside of the housing 2 flows from the air supply port 21 through the suction hole 34 to the exhaust port 22 inside the housing 2. Specifically, the air flow that has flowed into the inside of the housing 2 flows into the inside of the scroll casing 31 through the suction hole 34 from the air supply port 21, and then flows to the exhaust port 22 through the inside of the scroll casing 31. The air flow that has flowed to the exhaust port 22 flows out to the exhaust duct through the exhaust port 22.

[0020] Thereby, an air passage 23 inside the housing that guides the air flow from the air supply port 21 to the suction hole 34 is formed inside the housing 2. Also, an air passage 35 inside the casing that guides the air flow from the suction hole 34 to the exhaust port 22 is formed inside the scroll casing 31. The fan 32 is arranged in the air passage 35 inside the casing.

[0021] The sound-absorbing member 4 is provided on the inner surface of the housing 2. In the present embodiment, the sound-absorbing member 4 is fixed to the first side wall 2c. As a result, in the present embodiment, the thickness direction of the sound-absorbing member 4 coincides with the lateral direction Y of the housing 2, and the width direction of the sound-absorbing member 4 coincides with the longitudinal direction Z of the housing 2. As the sound-absorbing member 4, for example, a porous body such as glass wool made of glass fiber is used.

[0022] A reference direction along the inner surface of the housing 2 is set for the sound-absorbing member 4. The reference direction of the sound-absorbing member 4 is the direction along the inner surface of the housing 2 where the sound-absorbing member 4 is provided. Therefore, in the present embodiment, the direction along the first side wall 2c is the reference direction of the sound-absorbing member 4. Also, in the present embodiment, the reference direction of the sound-absorbing member 4 coincides with the axial direction X of the housing 2. The suction hole 34 is located at a position away from the air supply port 21 in the reference direction of the sound-absorbing member 4, that is, in the axial direction X of the housing 2.

[0023] Also, a cross-sectionally deformed section S is set for the sound-absorbing member 4. The cross-sectionally deformed section S is a specific section in the reference direction of the sound-absorbing member 4. In the cross-sectionally deformed section S, the cross-sectional shape of the sound-absorbing member 4 in a plane orthogonal to the reference direction of the sound-absorbing member 4 is different from a rectangular shape. In the present embodiment, the cross-sectionally deformed section S is set over the entire sound-absorbing member 4 in the reference direction of the sound-absorbing member 4. That is, in the present embodiment, the cross-sectional shape of the sound-absorbing member 4 in a plane orthogonal to the reference direction of the sound-absorbing member 4 is different from a rectangular shape over the entire sound-absorbing member 4 in the reference direction. Also, in the present embodiment, the cross-sectional shape of the sound-absorbing member 4 in a plane orthogonal to the reference direction of the sound-absorbing member 4 is the same at any position in the reference direction of the sound-absorbing member 4.

[0024] The sound-absorbing member 4 has a sound-absorbing base portion 41 and a sound-absorbing protrusion portion 42. In the present embodiment, the sound-absorbing protrusion portion 42 is a separate member from the sound-absorbing base portion 41.

[0025] The sound-absorbing base portion 41 is fixed to the inner surface of the housing 2. In the present embodiment, the sound-absorbing base portion 41 is fixed to the first side wall 2c. The shape of the sound-absorbing base portion 41 is plate-like along the inner surface of the housing 2. Therefore, in the present embodiment, as shown in FIG. 3, the cross-sectional shape of the sound-absorbing base portion 41 in a plane orthogonal to the reference direction of the sound-absorbing member 4 is rectangular.

[0026] On the sound-absorbing base portion 41, a protrusion forming surface 41a is formed facing the air passage 23 inside the housing. As a result, a part of the protrusion forming surface 41a faces the suction hole forming surface 31a of the scroll casing 31. In the present embodiment, the protrusion forming surface 41a is orthogonal to the lateral direction Y of the housing 2.

[0027] The sound-absorbing protrusion 42 protrudes along the thickness direction of the sound-absorbing member 4 from the protrusion forming surface 41a toward the air passage 23 inside the housing in the cross-sectionally deformed section S. Therefore, in the present embodiment, the sound-absorbing protrusions 42 are arranged over the entire sound-absorbing base portion 41 in the reference direction of the sound-absorbing member 4. Also, in the present embodiment, as shown in FIG. 3, the cross-sectional shape of the sound-absorbing protrusion 42 in a plane orthogonal to the reference direction of the sound-absorbing member 4 is rectangular.

[0028] In the cross-section of the sound-absorbing member 4 in a plane orthogonal to the reference direction of the sound-absorbing member 4, the sound-absorbing protrusion 42 protrudes only from a part of the protrusion forming surface 41a. In the present embodiment, as shown in FIG. 3, in the cross-section of the sound-absorbing member 4 in a plane orthogonal to the reference direction of the sound-absorbing member 4, the sound-absorbing protrusion 42 protrudes from the central portion of the protrusion forming surface 41a. Therefore, the dimension of the sound-absorbing protrusion 42 in the width direction of the sound-absorbing member 4 is smaller than the dimension of the sound-absorbing base portion 41 in the width direction of the sound-absorbing member 4.

[0029] On the sound-absorbing member 4, a sound-absorbing exposed surface 40 that is exposed to the air passage 23 inside the housing is formed. In the present embodiment, the sound-absorbing exposed surface 40 is formed by the portions of the outer surface of the sound-absorbing protrusion 42 and the protrusion forming surface 41a that are exposed to the air passage 23 inside the housing.

[0030] On the sound-absorbing exposed surface 40, a sound-absorbing upper end portion 40a is formed in the cross-sectionally deformed section S. In the cross-sectionally deformed section S, in the cross-section of the sound-absorbing member 4 in a plane orthogonal to the reference direction of the sound-absorbing member 4, the thickness of the sound-absorbing member 4 at the position of the sound-absorbing upper end portion 40a is greater than the thickness of the sound-absorbing member 4 at a position deviated from the sound-absorbing upper end portion 40a. In the present embodiment, the end face of the sound-absorbing protrusion 42 facing the air passage 23 inside the housing is the sound-absorbing upper end portion 40a.

[0031] At the position where the sound-absorbing protrusion 42 protrudes from the protrusion forming surface 41a, the thickness of the sound-absorbing member 4 is greater than at the position where the sound-absorbing protrusion 42 does not protrude from the protrusion forming surface 41a. Therefore, in the present embodiment, the end face of the sound-absorbing protrusion 42 farthest from the protrusion forming surface 41a is the sound-absorbing upper end portion 40a.

[0032] A part of the sound-absorbing upper end portion 40a faces the suction hole 34. In the present embodiment, a part of the sound-absorbing upper end portion 40a faces the suction hole 34 in the lateral direction Y of the housing 2.

[0033] Next, the operation of the blower 1 will be described. When the fan 32 rotates by the driving force of the motor 33 of the centrifugal blower 3, the air in the indoor space is taken in as an air current into the air supply duct. The air current taken into the air supply duct flows into the interior of the housing 2 through the air supply port 21.

[0034] After that, the air current flows through the interior of the housing 2 in the order of the air passage 23 inside the housing and the air passage 35 inside the casing. At this time, a part of the air current flowing through the air passage 23 inside the housing is guided to the suction hole 34 while being guided by the sound-absorbing protrusion 42 of the sound-absorbing member 4. After that, the air current flows out to the exhaust duct through the exhaust port 22 after flowing through the air passage 35 inside the casing. After that, the air current is discharged outdoors through the exhaust duct. Thereby, the air in the indoor space is discharged outdoors, and ventilation of the indoor space is performed.

[0035] When the blower device 1 operates, the operating sound generated from the motor 33 and the fan 32, the wind noise generated when the airflow flows through the air passage 23 inside the housing and the air passage 35 inside the casing are transmitted as the blowing sound to the space inside the housing 2. At this time, the blowing sound is absorbed by the sound-absorbing member 4. Thereby, the transmission of the blowing sound from the inside of the housing 2 to the outside of the housing 2 is suppressed. That is, the housing 2 functions as a soundproof box that suppresses the transmission of the blowing sound from the inside of the housing 2 to the outside of the housing 2.

[0036] In such a blower device 1, a sound-absorbing upper end portion 40a is formed on the sound-absorbing exposed surface 40 of the sound-absorbing member 4 in the cross-sectionally deformed section S. In the cross-sectionally deformed section S, in the cross-section of the sound-absorbing member 4 in a plane orthogonal to the reference direction of the sound-absorbing member 4, the thickness of the sound-absorbing member 4 at the position of the sound-absorbing upper end portion 40a is thicker than the thickness of the sound-absorbing member 4 at a position deviated from the sound-absorbing upper end portion 40a. A part of the sound-absorbing upper end portion 40a faces the suction hole 34 of the centrifugal blower 3. Therefore, the thick portion of the sound-absorbing member 4 can be opposed to the suction hole 34. Thereby, the blowing sound transmitted from the inside of the centrifugal blower 3 through the suction hole 34 to the air passage 23 inside the housing can be effectively absorbed by the sound-absorbing member 4. Also, the blowing sound generated by the airflow flowing through the air passage 23 inside the housing can be absorbed by the sound-absorbing member 4. Therefore, the blowing sound generated inside the housing 2 can be made difficult to be transmitted to the outside of the housing 2, and the noise of the blower device 1 can be reduced.

[0037] In addition, since the thickness of the sound-absorbing member 4 can be made thinner than the position of the sound-absorbing upper end portion 40a at positions other than the sound-absorbing upper end portion 40a, the cross-sectional area of the air passage of the air passage 23 inside the housing 2 can be increased. For this reason, the speed of the airflow flowing through the air passage 23 inside the housing can be reduced, and the wind noise of the airflow flowing through the air passage 23 inside the housing can be reduced. Thereby, further reduction of the noise of the blower device 1 can be achieved. Also, since the speed of the airflow flowing through the air passage 23 inside the housing can be reduced, the pressure loss of the airflow can be reduced. Thereby, a decrease in the blowing performance of the blower device 1 can also be suppressed. Furthermore, within the allowable range of the noise of the blower device 1, the output of the motor 33 can be increased, and the blowing performance of the blower device 1 can also be improved.

[0038] Furthermore, since the cross-sectional area of the air passage 23 inside the housing 2 can be increased, an increase in the size of the housing 2 can be prevented, and an increase in the size of the blower device 1 can be prevented. Thereby, it is possible to prevent the occurrence of disadvantages such as an increase in the cost of the housing 2 itself and the cost of packaging the housing 2, a decrease in the degree of freedom of equipment design due to an increase in the occupied area of the housing 2, and a decrease in the installation work efficiency due to an increase in the weight of the blower device 1. Also, by adjusting the output of the motor 33 and the cross-sectional area of the air passage 23 inside the housing, the size of the housing 2 can also be reduced.

[0039] Also, the cross-sectionally deformed section S in the sound-absorbing member 4 is set over the entire sound-absorbing member 4 in the reference direction of the sound-absorbing member 4. For this reason, the sound-absorbing upper end portion 40a can be formed over the entire sound-absorbing member 4 in the reference direction of the sound-absorbing member 4. Thereby, the airflow flowing through the air passage 23 inside the housing can be rectified along the sound-absorbing upper end portion 40a. Therefore, the magnitude of the wind noise generated by the airflow flowing through the air passage 23 inside the housing can be reduced. Thereby, further reduction of the noise of the blower device 1 can be achieved.

[0040] Next, in order to confirm the effect of the sound absorption member 4, a blower device according to each of Comparative Example 1 and Comparative Example 2 and a blower device 1 according to each of Example 3, Example 4, and Example 5 were prepared. Further, the static pressure and noise of the blower devices according to Comparative Example 1, Comparative Example 2, Example 3, Example 4, and Example 5 were measured. The measurement was performed at the same air volume in each of Comparative Example 1, Comparative Example 2, Example 3, Example 4, and Example 5. The air volume during the measurement was set to 1000 m3 / h in any of Comparative Example 1, Comparative Example 2, Example 3, Example 4, and Example 5. Hereinafter, Comparative Example 1, Comparative Example 2, Example 3, Example 4, and Example 5 may be collectively referred to as "each target example 1-5".

[0041] In each of the target examples 1-5, as shown in FIG. 2, the thickness of the sound absorption base portion 41 is A, the thickness of the sound absorption protrusion portion 42 is B, and the distance between the suction hole formation surface 31a and the sound absorption upper end portion 40a is C. Further, in each of the target examples 1-5, the dimension of the sound absorption protrusion portion 42 in the width direction of the sound absorption member 4 is D. Furthermore, in each of the target examples 1-5, among the sound absorption base portions 41 in the width direction of the sound absorption member 4, the dimension of the portion on the left side of the sound absorption protrusion portion 42 is E, and the dimension of the portion on the right side of the sound absorption protrusion portion 42 is F.

[0042] FIG. 4 is a table showing the measurement results of the static pressure and noise of the blower devices according to Comparative Example 1, Comparative Example 2, Example 3, Example 4, and Example 5. The total dimension of (A + B), the total dimension of (A + B + C), and the respective dimensions of D, E, and F are set as fixed values in each of the target examples 1-5. In each of the target examples 1-5, the total dimension of (A + B) is 50 mm, the total dimension of (A + B + C) is 114 mm, and the respective dimensions of D, E, and F are 100 mm. Therefore, in each of the target examples 1-5, the ratio of the total dimension of (A + B + C) to the total dimension of (A + B), that is, (A + B) / (A + B + C), is 0.44 in each case. Also, in Example 3, Example 4, and Example 5, the respective dimensions of D, E, and F are the same dimension.

[0043] The difference between Comparative Example 1, Comparative Example 2, Example 3, Example 4, and Example 5 lies in the relationship between the dimension of A and the dimension of B in the sound absorption member 4.

[0044] In Comparative Example 1, the dimension of A is 50 mm and the dimension of B is 0 mm. Therefore, in Comparative Example 1, there is no sound-absorbing protrusion 42, and the sound-absorbing member 4 is constituted only by the sound-absorbing base portion 41.

[0045] In Comparative Example 2, the dimension of A is 0 mm and the dimension of B is 50 mm. Therefore, in Comparative Example 2, there is no sound-absorbing base portion 41, and the sound-absorbing member 4 is constituted only by the sound-absorbing protrusion 42.

[0046] On the other hand, in Example 3, the dimension of A is 10 mm and the dimension of B is 40 mm. Therefore, in Example 3, the ratio of the total dimension of (A + B) to the dimension of A, that is, A / (A + B), is 0.20.

[0047] In Example 4, the dimension of A is 20 mm and the dimension of B is 30 mm. Therefore, in Example 4, A / (A + B) is 0.40.

[0048] In Example 5, the dimension of A is 30 mm and the dimension of B is 20 mm. Therefore, in Example 5, A / (A + B) is 0.60.

[0049] Regarding the noise of the blower device according to each of the target examples 1 to 5, the intake-side noise at a position facing the intake port 21 outside the housing 2 and the side noise at a position facing the first side wall 2c outside the housing 2 were measured. Also, for the comparison of the noise of the blower device according to each of the target examples 1 to 5, the specific noise of each of the intake-side noise and the side noise was used. Furthermore, each of the target examples 1 to 5 was compared with reference to Comparative Example 1. Also, the comparison of each of the target examples 1 to 5 was performed in two cases: when the power supply frequency is 50 Hz and when the power supply frequency is 60 Hz.

[0050] In the measurement results of the static pressure of the air blower, as shown in FIG. 4, it was found that the static pressure of the air blowers according to Comparative Example 2 and Examples 3 to 5 was higher than that of the air blower according to Comparative Example 1. Therefore, it was confirmed that the air blowing performance of the air blowers according to Comparative Example 2 and Examples 3 to 5 was higher than that of the air blower according to Comparative Example 1.

[0051] Also, in the measurement results of the noise of the air blower, as shown in FIG. 4, it was confirmed that in the air blowers according to Examples 3 to 5, the specific noise of both the air supply side noise and the side surface noise was lower than that of Comparative Example 1. On the other hand, in the air blower according to Comparative Example 2, the specific noise of the air supply side noise when the power supply frequency is 60 Hz is higher than that of Comparative Example 1.

[0052] Therefore, it was confirmed that in each of the air blowers according to Examples 3 to 5, the noise was reduced and the air blowing performance was improved with respect to the air blower according to Comparative Example 1. Thereby, in the air blower 1, when (A + B) / (A + B + C) is 0.44 and A / (A + B) is a value within the range of 0.20 to 0.60, it was confirmed that the effects of both noise reduction and improvement of air blowing performance were increased.

[0053] FIG. 5 is a graph comparing the static pressure of the air blower between Comparative Example 1 and Example 4. In FIG. 5, the static pressure of the air blower according to Comparative Example 1 is set to 100%, and the vertical axis is the static pressure ratio which is the ratio of the static pressure to the static pressure of the air blower according to Comparative Example 1. From the graph of FIG. 5, it can be seen that the static pressure of the air blower according to Example 4 is significantly improved with respect to the static pressure of the air blower according to Comparative Example 1.

[0054] Figure 6 is a graph comparing the specific noises of the intake-side noise and the side noise of the blower in Comparative Example 1 and Example 4. In Figure 6, the specific noises of the intake-side noise in Comparative Example 1 and Example 4 are shown as L1a and L4a respectively, and the specific noises of the side noise in Comparative Example 1 and Example 4 are shown as L1b and L4b respectively. Also, in Figure 6, the specific noises L1a and L1b of the blower according to Comparative Example 1 are set to 100%. From the graph of Figure 6, it can be seen that both the intake-side noise and the side noise of the blower according to Example 4 are significantly reduced compared to the intake-side noise and the side noise of the blower according to Comparative Example 1.

[0055] From this, it can be seen that in the blower according to Example 4 where (A + B) / (A + B + C) is 0.44 and A / (A + B) is 0.30, the noise reduction effect and the improvement effect of the blowing performance are particularly high.

[0056] In Embodiment 1, the cross-sectional shape of the sound absorption protrusion 42 in the plane orthogonal to the reference direction of the sound absorption member 4 is rectangular. However, the cross-sectional shape of the sound absorption protrusion 42 in the plane orthogonal to the reference direction of the sound absorption member 4 is not limited to this. For example, the cross-sectional shape of the sound absorption protrusion 42 in the plane orthogonal to the reference direction of the sound absorption member 4 may be triangular, semi-circular, or the like.

[0057] Embodiment 2. Figure 7 is a cross-sectional view showing the blower according to Embodiment 2. Figure 7 corresponds to Figure 3 in Embodiment 1. In the present embodiment, the cross-sectional shape of the sound absorption protrusion 42 in the plane orthogonal to the reference direction of the sound absorption member 4 is triangular.

[0058] The sound-absorbing protrusion 42 protrudes from the entire surface of the protrusion forming surface 41a of the sound-absorbing base portion 41. The sound-absorbing exposed surface 40 of the sound-absorbing member 4 exposed in the air passage 23 inside the housing is formed on the sound-absorbing protrusion 42. The cross-sectional shape of the sound-absorbing protrusion 42 is a triangular shape with the bottom side coinciding with the protrusion forming surface 42a and the apex facing the air passage 23 inside the housing. On the sound-absorbing exposed surface 40, the apex of the triangular shape in the cross-section of the sound-absorbing protrusion 42 forms a ridge line along the reference direction of the sound-absorbing member 4. Therefore, the ridge line formed on the sound-absorbing exposed surface 40 faces the air passage 23 inside the housing.

[0059] In the cross-sectionally irregular section S, in the cross-section of the sound-absorbing member 4 in a plane orthogonal to the reference direction of the sound-absorbing member 4, the thickness of the sound-absorbing member 4 at the position of the ridge line of the sound-absorbing exposed surface 40 is thicker than the thickness of the sound-absorbing member 4 at a position deviated from the ridge line. Therefore, the ridge line formed on the sound-absorbing exposed surface 40 serves as the sound-absorbing upper end portion 40a. A part of the sound-absorbing upper end portion 40a faces the suction hole 34. Other configurations are the same as those in the first embodiment.

[0060] In this way, even if the cross-sectional shape of the sound-absorbing protrusion 42 in a plane orthogonal to the reference direction of the sound-absorbing member 4 is triangular, the thick portion of the sound-absorbing member 4 can be made to face the suction hole 34. Thereby, the blowing sound generated inside the housing 2 can be made less likely to be transmitted to the outside of the housing 2, and the noise of the blower 1 can be reduced. Also, since the thickness of the sound-absorbing member 4 can be made thinner than the position of the sound-absorbing upper end portion 40a at positions other than the sound-absorbing upper end portion 40a, the cross-sectional area of the air passage 23 inside the housing 2 can be enlarged. Thereby, a decrease in the blowing performance of the blower 1 can also be suppressed. Furthermore, an increase in the size of the blower 1 can be prevented.

[0061] Note that in the second embodiment, the cross-sectional shape of the sound-absorbing protrusion 42 in a plane orthogonal to the reference direction of the sound-absorbing member 4 is triangular. However, the cross-sectional shape of the sound-absorbing protrusion 42 in a plane orthogonal to the reference direction of the sound-absorbing member 4 is not limited to this. For example, the cross-sectional shape of the sound-absorbing protrusion 42 in a plane orthogonal to the reference direction of the sound-absorbing member 4 may be a semi-circular shape or the like.

[0062] Also, in Embodiment 2, the sound-absorbing base portion 41 may be eliminated, and only the sound-absorbing protrusion portions 42 may be arranged as the sound-absorbing member 4. That is, in Embodiment 2, the cross-sectional shape of the sound-absorbing member 4 in a plane orthogonal to the reference direction of the sound-absorbing member 4 may be triangular. In this case, for example, the cross-sectional shape of the sound-absorbing member 4 in a plane orthogonal to the reference direction of the sound-absorbing member 4 may be semicircular or the like.

[0063] Also, in Embodiments 1 and 2, the cross-sectionally deformed section S is set over the entire sound-absorbing base portion 41 in the reference direction of the sound-absorbing member 4. However, a section shorter than the range of the sound-absorbing base portion 41 in the reference direction of the sound-absorbing member 4 may be set as the cross-sectionally deformed section S in the sound-absorbing member 4. In this case, a sound-absorbing upper end portion 40a is formed on the sound-absorbing exposed surface 40 in the cross-sectionally deformed section S, and at least a part of the sound-absorbing upper end portion 40a faces the suction hole 34. Even in this way, it is possible to reduce the noise of the blower device 1 and suppress a decrease in the blowing performance in the blower device 1. Also, it is possible to prevent the blower device 1 from becoming larger in size.

[0064] Embodiment 3. FIG. 8 is a schematic configuration diagram showing a blower device according to Embodiment 3. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. FIG. 10 is a cross-sectional view taken along line X-X in FIG. 8. The cross-sectionally deformed section S set in the reference direction of the sound-absorbing member 4 is a section shorter than the range of the sound-absorbing base portion 41 in the reference direction of the sound-absorbing member 4. Therefore, the sound-absorbing protrusion portions 42 located in the cross-sectionally deformed section S protrude from the protrusion forming surface 41a only in a partial range of the sound-absorbing base portion 41 in the reference direction of the sound-absorbing member 4. Among the outer surface of the sound-absorbing protrusion portions 42 and the protrusion forming surface 41a, the portion exposed to the air passage 23 in the housing is the sound-absorbing exposed surface 40. In the present embodiment, all of the sound-absorbing protrusion portions 42 face the suction hole 34.

[0065] The shape of the sound-absorbing protrusion 42 is a conical shape with the bottom surface coinciding with the protrusion forming surface 41a and the apex facing the air passage 23 inside the housing. In the present embodiment, the shape of the sound-absorbing protrusion 42 is a quadrangular pyramid. Further, in the present embodiment, as shown in FIG. 10, the direction along the diagonal of the bottom surface of the sound-absorbing protrusion 42 coincides with the reference direction of the sound-absorbing member 4.

[0066] On the sound-absorbing exposed surface 40 formed on the sound-absorbing protrusion 42, a sound-absorbing upper end portion 40a including the apex of the sound-absorbing protrusion 42 is formed. In the present embodiment, when the sound-absorbing protrusion 42 is viewed along the thickness direction of the sound-absorbing member 4, the sound-absorbing upper end portion 40a is formed on the sound-absorbing exposed surface 40 of the sound-absorbing protrusion 42 along the reference direction of the sound-absorbing member 4. In the cross-sectionally deformed section S, in the cross-section of the sound-absorbing member 4 in a plane orthogonal to the reference direction of the sound-absorbing member 4, the thickness of the sound-absorbing member 4 at the position of the sound-absorbing upper end portion 40a is thicker than the thickness of the sound-absorbing member 4 at a position deviated from the sound-absorbing upper end portion 40a. Other configurations are the same as those in the first embodiment.

[0067] Thus, even if the shape of the sound-absorbing protrusion 42 is conical, the thick portion of the sound-absorbing member 4 can be opposed to the suction hole 34. Thereby, the reduction of the noise of the blower 1 can be achieved. Further, since the thickness of the sound-absorbing member 4 can be made thinner than the position of the sound-absorbing upper end portion 40a at positions other than the sound-absorbing upper end portion 40a, the cross-sectional area of the air passage 23 inside the housing 2 can be enlarged. Thereby, the decrease in the blowing performance of the blower 1 can also be suppressed. Furthermore, the enlargement of the size of the blower 1 can be prevented.

[0068] Further, the cross-sectionally deformed section S is a section shorter than the range of the sound-absorbing base portion 41 in the reference direction of the sound-absorbing member 4. Therefore, the cross-sectional area of the air passage 23 inside the housing 2 can be further enlarged. Thereby, the decrease in the blowing performance of the blower 1 can be further suppressed, and the enlargement of the size of the blower 1 can be further prevented.

[0069] In addition, in the third embodiment, the shape of the sound absorption protrusion 42 is a square pyramid. However, the shape of the sound absorption protrusion 42 is not limited to this. For example, the shape of the sound absorption protrusion 42 may be a cone, a triangular pyramid, etc. Also, the shape of the sound absorption protrusion 42 may be a rectangular parallelepiped shape, a hemispherical shape, etc. Even in this way, it is possible to reduce the noise of the blower 1 and suppress the decrease in the blowing performance of the blower 1. Also, it is possible to prevent the blower 1 from becoming larger in size.

[0070] Also, in the third embodiment, the cross-sectionally irregular section S is a section shorter than the range of the sound absorption base portion 41 in the reference direction of the sound absorption member 4. However, the cross-sectionally irregular section S may be set over the entire sound absorption base portion 41 in the reference direction of the sound absorption member 4. In this case, the apex of the sound absorption protrusion 42 faces the suction hole 34. Even in this way, it is possible to reduce the noise of the blower 1 and suppress the decrease in the blowing performance of the blower 1. Also, it is possible to prevent the blower 1 from becoming larger in size.

[0071] Also, in each of the above embodiments, the number of suction holes 34 formed in the scroll casing 31 of the centrifugal blower 3 is one. However, the number of suction holes 34 formed in the scroll casing 31 may be plural. In this case, a plurality of sound absorption members 4 corresponding to the plurality of suction holes 34 are provided on the inner surface of the casing 2. Also, in this case, at least a part of the sound absorption upper end portion 40a formed on the sound absorption exposed surface 40 of each sound absorption member 4 faces the corresponding suction hole 34.

[0072] For example, a centrifugal blower 3 having two suction holes 34 formed in a scroll casing 31 may be provided inside a housing 2. In this case, the scroll casing 31 is provided inside the housing 2 with one suction hole 34 facing the first side wall 2c and the other suction hole 34 facing the second side wall 2d. Also, in this case, one sound-absorbing member 4 corresponding to one suction hole 34 is provided on the first side wall 2c, and the other sound-absorbing member 4 corresponding to the other suction hole 34 is provided on the second side wall 2d. Further, in this case, at least a part of a sound-absorbing upper end portion 40a formed in one sound-absorbing member 4 faces one suction hole 34, and at least a part of a sound-absorbing upper end portion 40a formed in the other sound-absorbing member 4 faces the other suction hole 34. In this way, even if the centrifugal blower 3 having a plurality of suction holes 34 is provided inside the housing 2, it is possible to effectively reduce the noise of the blower device 1 and suppress a decrease in the blowing performance in the blower device 1. Also, it is possible to effectively prevent an increase in the size of the blower device 1.

[0073] Also, in each of the above embodiments, the sound-absorbing protrusion 42 is a separate member from the sound-absorbing base 41. However, one member without a boundary between the sound-absorbing protrusion 42 and the sound-absorbing base 41 may be the sound-absorbing member 4.

Description of Reference Numerals

[0074] 1 Blower device, 2 Housing, 3 Centrifugal blower, 4 Sound-absorbing member, 21 Air supply port, 22 Exhaust port, 23 Air passage inside the housing, 31a Suction hole formation surface, 34 Suction hole, 40 Sound-absorbing exposed surface, 40a Sound-absorbing upper end portion, 41 Sound-absorbing base, 41a Protrusion formation surface, 42 Sound-absorbing protrusion.

Claims

1. A housing in which an air supply port and an exhaust port are formed, A centrifugal blower provided inside the housing and having an intake hole formed therein, A sound-absorbing member provided on the inner surface of the housing, and comprising: The centrifugal blower generates an air flow that flows from the air supply port through the intake hole to the exhaust port, Inside the housing, an air passage inside the housing for guiding the air flow from the air supply port to the intake hole is formed, In the sound-absorbing member, a reference direction along the inner surface of the housing and a cross-sectionally deformed section which is a specific section in the reference direction are set, The intake hole is located at a position away from the air supply port in the reference direction, In the sound-absorbing member, a sound-absorbing exposed surface exposed to the air passage inside the housing is formed, On the sound-absorbing exposed surface, a sound-absorbing upper end portion is formed in the cross-sectionally deformed section, At least a part of the sound-absorbing upper end portion faces the intake hole, In the cross-sectionally deformed section, in the cross-section of the sound-absorbing member in a plane perpendicular to the reference direction, the thickness of the sound-absorbing member at the position of the sound-absorbing upper end portion is thicker than the thickness of the sound-absorbing member at a position deviated from the sound-absorbing upper end portion. A blower device.

2. The blower device according to claim 1, wherein the cross-sectionally deformed section is set over the entire sound-absorbing member in the reference direction.

3. The sound-absorbing member has a sound-absorbing base portion with a protrusion forming surface formed toward the air passage inside the housing, and a sound-absorbing protrusion portion protruding from the protrusion forming surface toward the air passage inside the housing in the cross-sectionally deformed section, The cross-sectional shape of the sound-absorbing protrusion portion in a plane perpendicular to the reference direction is rectangular, An end face of the sound-absorbing protrusion portion facing the air passage inside the housing is the sound-absorbing upper end portion, The intake hole is formed in an intake hole forming surface of the centrifugal blower. When the thickness of the sound-absorbing base portion is A, the thickness of the sound-absorbing protrusion portion is B, and the distance between the suction hole formation surface and the sound-absorbing upper end portion is C, (A + B) / (A + B + C) is 0.44, and A / (A + B) is a value within the range of 0.20 to 0.

60. The blower device according to claim 2.

4. The sound-absorbing member has a sound-absorbing base portion formed with a protrusion formation surface facing the air passage in the housing, and a sound-absorbing protrusion portion protruding from the protrusion formation surface toward the air passage in the housing in the cross-sectionally deformed section. The cross-sectional shape of the sound-absorbing protrusion portion in a plane orthogonal to the reference direction is a triangular shape. The blower device according to claim 1 or claim 2, wherein a ridge line of the sound-absorbing protrusion portion facing the air passage in the housing is the sound-absorbing upper end portion.

5. The sound-absorbing member has a sound-absorbing base portion formed with a protrusion formation surface facing the air passage in the housing, and a sound-absorbing protrusion portion protruding from the protrusion formation surface toward the air passage in the housing in the cross-sectionally deformed section. The shape of the sound-absorbing protrusion portion is a cone shape with a vertex arranged toward the air passage in the housing. The blower device according to claim 1 or claim 2, wherein the sound-absorbing upper end portion including the vertex is formed on the sound-absorbing exposed surface.

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