Blower

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 casing 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 in the sound-absorbing member. Therefore, 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 addresses the above problems and aims to provide a blower device capable of suppressing a decrease in blowing performance while reducing noise.

Means for Solving the Problems

[0006] The blower according to this disclosure comprises a housing having an air intake port and an exhaust port, a centrifugal blower provided inside the housing and having an intake port, and a sound-absorbing member provided on the inner surface of the housing. The centrifugal blower generates an airflow that flows from the air intake port through the intake port to the exhaust port, and an internal air passage is formed inside the housing that guides the airflow from the air intake port to the intake port. The sound-absorbing member has a reference direction along the inner surface of the housing and a specific section in the reference direction which is a cross-sectional irregular section. The intake port is located away from the air intake port in the reference direction. The sound-absorbing member has a sound-absorbing exposed surface that is exposed to the internal air passage. The sound-absorbing exposed surface has a sound-absorbing upper end located in the cross-sectional irregular section, and at least a part of the sound-absorbing upper end faces the intake port. In the cross-sectional irregular 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 is greater than the thickness of the sound-absorbing member at a position away from the sound-absorbing upper end. [Effects of the Invention]

[0007] According to this disclosure, it is possible to reduce noise while suppressing a decrease in airflow performance. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing a blower according to Embodiment 1. [Figure 2] Figure 1 is a schematic diagram showing the configuration of the blower device. [Figure 3] This is a cross-sectional view along line III-III in Figure 2. [Figure 4] This table shows the measurement results of static pressure and noise of the blower devices for Comparative Example 1, Comparative Example 2, Example 3, Example 4, and Example 5, respectively. [Figure 5] This graph compares the static pressure of the blower between Comparative Example 1 and Example 4. [Figure 6] This graph compares the specific noise levels of the air supply side noise and side noise of the blower between Comparative Example 1 and Example 4. [Figure 7] This is a cross-sectional view showing a blower according to Embodiment 2. [Figure 8] This is a schematic diagram showing the blower according to Embodiment 3. [Figure 9] This is a cross-sectional view along the line IX-IX in Figure 8. [Figure 10] This is a cross-sectional view along line XX in Figure 8. [Modes for carrying out the invention]

[0009] The embodiments for carrying out the subject matter of this disclosure will be described with reference to the attached figures. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are simplified or omitted as appropriate. The subject matter of this disclosure is not limited to the following embodiments, and any modification of any component of the embodiments or omission of any component of the embodiments is possible without departing from the spirit of this disclosure.

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

[0011] The housing 2 has an axis defined. Here, in the housing 2, the direction along the axis of the housing 2 is defined as the axial direction X, a specific direction perpendicular to the axial direction X is defined as the lateral direction Y, and the direction perpendicular to both the axial direction X and the lateral direction Y is defined as the vertical direction Z. The blower 1 is positioned so that the vertical direction Z of the housing 2 coincides 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 vertical direction Z of the housing 2. The shape of the housing 2 is a rectangular parallelepiped shape formed 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 outdoors 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 outdoors. 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 has an intake hole forming surface 31a formed thereon. The intake hole forming surface 31a is exposed to the space inside the housing 2 while facing the first side wall 2c. The intake hole forming surface 31a is orthogonal to the lateral direction Y of the housing 2. The intake hole 34 is formed in the intake 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 intake 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 from the air supply duct through the air supply port 21. The air flow that has flowed into the inside of the housing 2 flows from the air supply port 21 through the intake 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 from the air supply port 21 through the intake hole 34, 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 intake hole 34 is formed inside the housing 2. Also, an air passage 35 inside the casing that guides the air flow from the intake 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 this embodiment, the sound-absorbing member 4 is fixed to the first side wall 2c. As a result, in this 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 vertical direction Z of the housing 2. As the sound-absorbing member 4, a porous material such as glass wool made from glass fibers is used.

[0022] The sound-absorbing member 4 has a reference direction that aligns with the inner surface of the housing 2. The reference direction of the sound-absorbing member 4 is the direction along the inner surface of the housing 2 on which the sound-absorbing member 4 is installed. Therefore, in this embodiment, the direction along the first side wall 2c is set as the reference direction of the sound-absorbing member 4. Also, in this embodiment, the reference direction of the sound-absorbing member 4 coincides with the axial direction X of the housing 2. The intake hole 34 is located away from the air intake port 21 in the reference direction of the sound-absorbing member 4, that is, in the axial direction X of the housing 2.

[0023] Furthermore, the sound-absorbing member 4 has a section S with an irregular cross-sectional shape. The section S with an irregular cross-sectional shape is a specific section of the sound-absorbing member 4 in the reference direction. In the section S with an irregular cross-sectional shape, the cross-sectional shape of the sound-absorbing member 4 in a plane perpendicular to the reference direction of the sound-absorbing member 4 is different from a rectangular shape. In this embodiment, the section S with an irregular cross-sectional shape is set over the entire sound-absorbing member 4 in the reference direction. That is, in this embodiment, the cross-sectional shape of the sound-absorbing member 4 in a plane perpendicular 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 this embodiment, the cross-sectional shape of the sound-absorbing member 4 in a plane perpendicular 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 projection portion 42. In this embodiment, the sound-absorbing projection portion 42 is a separate component 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 this 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, conforming to the inner surface of the housing 2. Therefore, in this embodiment, as shown in Figure 3, the cross-sectional shape of the sound-absorbing base portion 41 in a plane perpendicular to the reference direction of the sound-absorbing member 4 is rectangular.

[0026] The sound-absorbing base portion 41 has a projection-forming surface 41a that faces the air passage 23 inside the housing. As a result, a portion of the projection-forming surface 41a faces the intake hole-forming surface 31a of the scroll casing 31. In this embodiment, the projection-forming surface 41a is perpendicular to the lateral direction Y of the housing 2.

[0027] The sound-absorbing protrusions 42 project from the protrusion-forming surface 41a toward the air passage 23 inside the housing along the thickness direction of the sound-absorbing member 4 in the irregularly shaped cross-section section S. Therefore, in this 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. Furthermore, in this embodiment, as shown in Figure 3, the cross-sectional shape of the sound-absorbing protrusions 42 in a plane perpendicular 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 perpendicular to the reference direction of the sound-absorbing member 4, the sound-absorbing protrusion 42 protrudes only from a portion of the protrusion-forming surface 41a. In this embodiment, as shown in Figure 3, in the cross-section of the sound-absorbing member 4 in a plane perpendicular to the reference direction of the sound-absorbing member 4, the sound-absorbing protrusion 42 protrudes from the central part of the protrusion-forming surface 41a. Therefore, the dimensions of the sound-absorbing protrusion 42 in the width direction of the sound-absorbing member 4 are smaller than the dimensions of the sound-absorbing base portion 41 in the width direction of the sound-absorbing member 4.

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

[0030] The sound-absorbing exposed surface 40 has a sound-absorbing upper end portion 40a formed in the cross-sectional irregular section S. In the cross-sectional irregular section S, in the cross-section of the sound-absorbing member 4 in a plane perpendicular 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 away from the sound-absorbing upper end portion 40a. In this embodiment, the end face of the sound-absorbing projection 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 projection 42 protrudes from the projection-forming surface 41a, the thickness of the sound-absorbing member 4 is greater than at the position where the sound-absorbing projection 42 does not protrude from the projection-forming surface 41a. Therefore, in this embodiment, the end face of the sound-absorbing projection 42 furthest from the projection-forming surface 41a is the sound-absorbing upper end portion 40a.

[0032] A portion of the upper sound-absorbing end portion 40a faces the intake port 34. In this embodiment, a portion of the upper sound-absorbing end portion 40a faces the intake port 34 in the lateral direction Y of the housing 2.

[0033] Next, the operation of the blower 1 will be explained. When the fan 32 rotates due to the driving force of the motor 33 of the centrifugal blower 3, air from the room space is drawn into the supply air duct as an airflow. The airflow drawn into the supply air duct flows into the interior of the housing 2 through the air intake port 21.

[0034] Subsequently, the airflow flows through the inside of the housing 2, first through the internal air passage 23 and then through the internal casing air passage 35. At this time, a portion of the airflow flowing through the internal air passage 23 is guided by the sound-absorbing projection 42 of the sound-absorbing member 4 and led to the intake port 34. After this, the airflow flows through the internal casing air passage 35 and then flows out through the exhaust port 22 into the exhaust duct. After this, the airflow is discharged to the outside through the exhaust duct. As a result, the air in the indoor space is discharged to the outside, and the indoor space is ventilated.

[0035] When the blower 1 is activated, operating noise generated from the motor 33 and fan 32, and wind noise generated when the airflow passes through the internal air passage 23 and the internal air passage 35 of the housing, are transmitted as blower noise within the space inside the housing 2. At this time, the blower noise is absorbed by the sound-absorbing member 4. This suppresses the transmission of blower noise to the outside of the housing 2. In other words, the housing 2 functions as a sound-dampening box that suppresses the transmission of blower noise from the inside of the housing 2 to the outside of the housing 2.

[0036] In this type of blower 1, the sound-absorbing upper end portion 40a is formed on the sound-absorbing exposed surface 40 of the sound-absorbing member 4 in the irregularly shaped cross-section section S. In the irregularly shaped cross-section section S, in the cross-section of the sound-absorbing member 4 in a plane perpendicular 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 away from the sound-absorbing upper end portion 40a. A portion of the sound-absorbing upper end portion 40a faces the intake port 34 of the centrifugal blower 3. Therefore, the thicker portion of the sound-absorbing member 4 can face the intake port 34. This allows the sound-absorbing member 4 to effectively absorb the blowing noise transmitted from inside the centrifugal blower 3 through the intake port 34 to the air passage 23 inside the housing. In addition, the blowing noise generated by the airflow in the air passage 23 inside the housing can also be absorbed by the sound-absorbing member 4. Therefore, it is possible to reduce the transmission of blowing noise generated inside the housing 2 to the outside of the housing 2, thereby reducing the noise of the blower 1.

[0037] Furthermore, since the thickness of the sound-absorbing member 4 can be made thinner at positions other than the upper sound-absorbing end 40a than at the upper sound-absorbing end 40a, the cross-sectional area of ​​the internal air passage 23 inside the housing 2 can be increased. As a result, the velocity of the airflow through the internal air passage 23 can be reduced, and the wind noise of the airflow through the internal air passage 23 can be reduced. This further reduces the noise of the blower 1. In addition, since the velocity of the airflow through the internal air passage 23 can be reduced, the pressure loss of the airflow can be reduced. This also suppresses a decrease in the blowing performance of the blower 1. Furthermore, the output of the motor 33 can be increased within the allowable noise range of the blower 1, thereby improving the blowing performance of the blower 1.

[0038] Furthermore, since the cross-sectional area of ​​the internal air passage 23 within the housing 2 can be increased, it is possible to prevent the housing 2 from becoming larger, and thus prevent the blower 1 from becoming larger. This prevents 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 in equipment design due to the increase in the occupied area of ​​the housing 2, and a decrease in installation work efficiency due to the increase in the weight of the blower 1. In addition, the housing 2 can be made smaller by adjusting the output of the motor 33 and the cross-sectional area of ​​the internal air passage 23.

[0039] Furthermore, the section S with an irregular cross-sectional shape in the sound-absorbing member 4 is set over the entire length of the sound-absorbing member 4 in the reference direction. Therefore, the sound-absorbing upper end portion 40a can be formed over the entire length of the sound-absorbing member 4 in the reference direction. This allows the airflow through the internal air passage 23 to be straightened along the sound-absorbing upper end portion 40a. Consequently, the amount of wind noise generated by the airflow through the internal air passage 23 can be reduced. This further reduces the noise of the blower 1.

[0040] Next, in order to confirm the effect of the sound-absorbing material 4, we prepared blowers according to Comparative Example 1 and Comparative Example 2, and blowers 1 according to Example 3, Example 4, and Example 5. We also measured the static pressure and noise of the blowers according to Comparative Example 1, Comparative Example 2, Example 3, Example 4, and Example 5. The measurements were performed at the same airflow rate for Comparative Example 1, Comparative Example 2, Example 3, Example 4, and Example 5. The airflow rate during measurement was 1000 m3 / h for all 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 "Target Examples 1-5".

[0041] In each of the examples 1 to 5, as shown in Figure 2, the thickness of the sound-absorbing base portion 41 is A, the thickness of the sound-absorbing projection portion 42 is B, and the distance between the intake hole forming surface 31a and the sound-absorbing upper end portion 40a is C. In addition, in each of the examples 1 to 5, the dimension of the sound-absorbing projection portion 42 in the width direction of the sound-absorbing member 4 is D. Furthermore, in each of the examples 1 to 5, the dimension of the part of the sound-absorbing base portion 41 to the left of the sound-absorbing projection portion 42 in the width direction of the sound-absorbing member 4 is E, and the dimension of the part to the right of the sound-absorbing projection portion 42 is F.

[0042] Figure 4 is a table showing the measurement results of static pressure and noise of the blower for Comparative Example 1, Comparative Example 2, Example 3, Example 4, and Example 5. The total dimensions of (A+B), the total dimensions of (A+B+C), and the individual dimensions of D, E, and F are fixed values ​​in each of the examples 1 to 5. In each of the examples 1 to 5, the total dimension of (A+B) is 50 mm, the total dimension of (A+B+C) is 114 mm, and the individual dimensions of D, E, and F are 100 mm. Therefore, in each of the examples 1 to 5, the ratio of the total dimension of (A+B+C) to the total dimension of (A+B), i.e., (A+B) / (A+B+C), is 0.44 in all cases. In addition, in Examples 3, 4, and 5, the individual dimensions of D, E, and F are the same.

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

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

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

[0046] In contrast, in Example 3, the dimension of A is set to 10 mm and the dimension of B is set to 40 mm. Therefore, in Example 3, the ratio of the total dimension of (A+B) to the dimension of A, i.e., A / (A+B), is 0.20.

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

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

[0049] For each of the examples 1 to 5, the noise levels of the blowers were measured as follows: 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. For comparison of the noise levels of the blowers in each of the examples 1 to 5, the specific noise levels of the intake-side noise and side noise were used. Furthermore, each of the examples 1 to 5 was compared against Comparative Example 1 as a baseline. The comparison of each of the examples 1 to 5 was also performed under two conditions: when the power supply frequency was 50 Hz and when it was 60 Hz.

[0050] As shown in Figure 4, the static pressure measurements of the blowers revealed that the static pressure of the blowers in Comparative Example 2 and Examples 3-5 was higher than that of the blower in Comparative Example 1. Therefore, it was confirmed that the blowing performance of the blowers in Comparative Example 2 and Examples 3-5 was higher than that of the blower in Comparative Example 1.

[0051] Furthermore, the noise measurement results for the blowers showed that, as shown in Figure 4, the specific noise levels for both the supply side noise and the side noise in the blowers according to Examples 3 to 5 were lower than those in Comparative Example 1. On the other hand, in the blower according to Comparative Example 2, the specific noise level of the supply side noise was higher than that of Comparative Example 1 when the power supply frequency was 60 Hz.

[0052] Therefore, it was confirmed that the blowers according to each of Examples 3 to 5 reduced noise and improved blowing performance compared to the blower according to Comparative Example 1. This confirmed that in blower 1, the effect of both noise reduction and improved blowing performance is greatest when (A+B) / (A+B+C) is 0.44 and A / (A+B) is within the range of 0.20 to 0.60.

[0053] Figure 5 is a graph comparing the static pressure of the blower in Comparative Example 1 and Example 4. In Figure 5, the static pressure of the blower in Comparative Example 1 is set to 100%, and the static pressure ratio, which is the ratio of the static pressure of Example 4 to the static pressure of the blower in Comparative Example 1, is plotted on the vertical axis. From the graph in Figure 5, it can be seen that the static pressure of the blower in Example 4 is significantly improved compared to the static pressure of the blower in Comparative Example 1.

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

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

[0056] In Embodiment 1, the cross-sectional shape of the sound-absorbing projection 42 in a plane perpendicular to the reference direction of the sound-absorbing member 4 is rectangular. However, the cross-sectional shape of the sound-absorbing projection 42 in a plane perpendicular 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 projection 42 in a plane perpendicular to the reference direction of the sound-absorbing member 4 may be triangular, semicircular, or the like.

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

[0058] The sound-absorbing projection 42 protrudes from the entire surface of the projection-forming surface 41a of the sound-absorbing base 41. The sound-absorbing exposed surface 40 of the sound-absorbing member 4 exposed to the air passage 23 inside the housing is formed on the sound-absorbing projection 42. The cross-sectional shape of the sound-absorbing projection 42 is triangular, with its base coinciding with the projection-forming surface 42a and its apex facing the air passage 23 inside the housing. On the sound-absorbing exposed surface 40, the triangular apex of the cross-section of the sound-absorbing projection 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 is oriented towards the air passage 23 inside the housing.

[0059] In the section S with an irregular cross-section, in the cross-section of the sound-absorbing member 4 in a plane perpendicular to the reference direction of the sound-absorbing member 4, the thickness of the sound-absorbing member 4 at the position of the ridge of the exposed sound-absorbing surface 40 is greater than the thickness of the sound-absorbing member 4 at a position away from the ridge. Therefore, the ridge formed on the exposed sound-absorbing surface 40 becomes the upper sound-absorbing end portion 40a. A portion of the upper sound-absorbing end portion 40a faces the intake hole 34. The other configurations are the same as in Embodiment 1.

[0060] Thus, even if the cross-sectional shape of the sound-absorbing projection 42 in a plane perpendicular to the reference direction of the sound-absorbing member 4 is triangular, the thicker portion of the sound-absorbing member 4 can be positioned opposite the intake hole 34. This makes it more difficult for the airflow noise generated inside the housing 2 to be transmitted to the outside of the housing 2, thereby reducing the noise of the blower 1. Furthermore, since the thickness of the sound-absorbing member 4 can be made thinner at positions other than the sound-absorbing upper end 40a than at the sound-absorbing upper end 40a, the cross-sectional area of ​​the airflow path 23 inside the housing 2 can be increased. This also suppresses a decrease in the airflow performance of the blower 1. Moreover, it helps to prevent the blower 1 from becoming larger.

[0061] In Embodiment 2, the cross-sectional shape of the sound-absorbing projection 42 in a plane perpendicular to the reference direction of the sound-absorbing member 4 is triangular. However, the cross-sectional shape of the sound-absorbing projection 42 in a plane perpendicular 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 projection 42 in a plane perpendicular to the reference direction of the sound-absorbing member 4 may be semicircular.

[0062] Furthermore, in Embodiment 2, the sound-absorbing base portion 41 may be omitted, and only the sound-absorbing projection portion 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 perpendicular 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 perpendicular to the reference direction of the sound-absorbing member 4 may be semicircular.

[0063] Furthermore, in embodiments 1 and 2, the irregularly shaped section S is set over the entire sound-absorbing base portion 41 in the reference direction of the sound-absorbing member 4. However, the irregularly shaped section S may be set for the sound-absorbing member 4 in a section shorter than the range of the sound-absorbing base portion 41 in the reference direction of the sound-absorbing member 4. In this case, the sound-absorbing upper end portion 40a is formed on the sound-absorbing exposed surface 40 in the irregularly shaped section S, and at least a part of the sound-absorbing upper end portion 40a faces the intake hole 34. Even in this way, it is possible to reduce the noise of the blower 1 and suppress the deterioration of the blowing performance of the blower 1. It is also possible to prevent the blower 1 from becoming larger.

[0064] Embodiment 3. Figure 8 is a schematic diagram showing the blower according to Embodiment 3. Figure 9 is a cross-sectional view along the line IX-IX in Figure 8. Figure 10 is a cross-sectional view along the line XX in Figure 8. The irregularly shaped section S set in the reference direction of the sound-absorbing member 4 is 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 protrusions 42 located in the irregularly shaped section S protrude from the protrusion-forming surface 41a only in a portion of the range of the sound-absorbing base portion 41 in the reference direction of the sound-absorbing member 4. Of the outer surface of the sound-absorbing protrusions 42 and the protrusion-forming surface 41a, the portion exposed to the air passage 23 inside the housing is the sound-absorbing exposed surface 40. In this embodiment, the entirety of the sound-absorbing protrusions 42 faces the intake hole 34.

[0065] The sound-absorbing projection 42 has a conical shape with its base surface aligned with the projection-forming surface 41a and its apex facing the air passage 23 inside the housing. In this embodiment, the sound-absorbing projection 42 is a square pyramid. Also, in this embodiment, as shown in Figure 10, the direction along the diagonal of the base surface of the sound-absorbing projection 42 coincides with the reference direction of the sound-absorbing member 4.

[0066] A sound-absorbing upper end portion 40a, including the apex of the sound-absorbing projection 42, is formed on the sound-absorbing exposed surface 40 of the sound-absorbing projection 42. In this embodiment, when the sound-absorbing projection 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 projection 42 along the reference direction of the sound-absorbing member 4. In the cross-sectional irregular section S, in the cross-section of the sound-absorbing member 4 in a plane perpendicular 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 away from the sound-absorbing upper end portion 40a. The other configurations are the same as in Embodiment 1.

[0067] In this way, even if the shape of the sound-absorbing projection 42 is conical, the thicker portion of the sound-absorbing member 4 can be positioned opposite the intake hole 34. This makes it possible to reduce the noise of the blower 1. Furthermore, since the thickness of the sound-absorbing member 4 can be made thinner at positions other than the sound-absorbing upper end 40a than at the sound-absorbing upper end 40a, the cross-sectional area of ​​the air passage 23 inside the housing 2 can be increased. This also makes it possible to suppress a decrease in the air-blowing performance of the blower 1. Moreover, it is possible to prevent the blower 1 from becoming larger.

[0068] Furthermore, the section with the irregular cross-section S is 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 increased. This further suppresses the deterioration of the air-blowing performance of the blower 1 and further prevents the blower 1 from becoming larger.

[0069] In Embodiment 3, the shape of the sound-absorbing projection 42 is a square pyramid. However, the shape of the sound-absorbing projection 42 is not limited to this. For example, the shape of the sound-absorbing projection 42 may be a cone, a triangular pyramid, or the like. Alternatively, the shape of the sound-absorbing projection 42 may be a rectangular parallelepiped, a hemisphere, or the like. In this way, it is possible to reduce the noise of the blower 1 and suppress the deterioration of the blowing performance of the blower 1. It is also possible to prevent the blower 1 from becoming larger.

[0070] Furthermore, in Embodiment 3, the section with the irregular cross-section S is shorter than the range of the sound-absorbing base portion 41 in the reference direction of the sound-absorbing member 4. However, the section with the irregular cross-section S may be set over the entire sound-absorbing base portion 41 in the reference direction of the sound-absorbing member 4. In this case, the apex of the sound-absorbing projection 42 faces the intake hole 34. Even in this way, it is possible to reduce the noise of the blower 1 and suppress the deterioration of the blowing performance of the blower 1. It is also possible to prevent the blower 1 from becoming larger.

[0071] Furthermore, in each of the above embodiments, there is one intake hole 34 formed in the scroll casing 31 of the centrifugal blower 3. However, there may be multiple intake holes 34 formed in the scroll casing 31. In this case, multiple sound-absorbing members 4 corresponding to the multiple intake holes 34 are provided on the inner surface of the housing 2. In this case, at least a portion of the sound-absorbing upper end portion 40a formed on the sound-absorbing exposed surface 40 of each sound-absorbing member 4 faces the corresponding intake hole 34.

[0072] For example, a centrifugal blower 3 having two intake holes 34 formed in a scroll casing 31 may be provided inside the housing 2. In this case, the scroll casing 31 is provided inside the housing 2 with one intake hole 34 facing the first side wall 2c and the other intake hole 34 facing the second side wall 2d. In this case, one sound-absorbing member 4 corresponding to one intake hole 34 is provided on the first side wall 2c, and the other sound-absorbing member 4 corresponding to the other intake hole 34 is provided on the second side wall 2d. Furthermore, in this case, at least a portion of the sound-absorbing upper end 40a formed on one sound-absorbing member 4 faces one intake hole 34, and at least a portion of the sound-absorbing upper end 40a formed on the other sound-absorbing member 4 faces the other intake hole 34. In this way, even if a centrifugal blower 3 with multiple intake holes 34 is provided inside the housing 2, it is possible to effectively reduce the noise of the blower 1 and suppress the deterioration of the blowing performance of the blower 1. Furthermore, this method effectively prevents the blower 1 from becoming excessively large.

[0073] Furthermore, in each of the above embodiments, the sound-absorbing projection 42 is a separate component from the sound-absorbing base 41. However, the sound-absorbing member 4 may be a single component without a boundary between the sound-absorbing projection 42 and the sound-absorbing base 41. [Explanation of Symbols]

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

Claims

1. A housing with an air intake and exhaust port formed therein, A centrifugal blower is provided inside the aforementioned housing and has an intake port formed therein, The sound-absorbing member provided on the inner surface of the aforementioned housing and Equipped with, The centrifugal blower generates an airflow that flows from the air intake port through the intake hole to the exhaust port, An internal air passage is formed inside the housing that guides the airflow from the air intake to the intake hole. The sound-absorbing member has a reference direction along the inner surface of the housing and a cross-sectional irregular section which is a specific section in the reference direction. The intake port is located at a position away from the air intake port in the reference direction, The sound-absorbing member has a sound-absorbing exposed surface that is exposed to the air passage inside the housing. The sound-absorbing exposed surface has a sound-absorbing upper end formed in the section with the irregular cross-sectional shape. At least a portion of the sound-absorbing upper end faces the intake hole, In the aforementioned section with an irregular cross-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 is greater than the thickness of the sound-absorbing member at a position away from the sound-absorbing upper end. The air blower is set so that the section with the irregular cross-section extends over the entire sound-absorbing member in the reference direction.

2. The sound-absorbing member has a sound-absorbing base portion with a projection-forming surface formed toward the air passage inside the housing, and a sound-absorbing projection portion that protrudes from the projection-forming surface toward the air passage inside the housing in the section with an irregular cross-sectional shape, The cross-sectional shape of the sound-absorbing projection in a plane perpendicular to the aforementioned reference direction is rectangular. The end face of the sound-absorbing projection facing the air passage inside the housing is the sound-absorbing upper end. The aforementioned intake port is formed on the intake port forming surface of the centrifugal blower, The blower according to claim 1, wherein, if the thickness of the sound-absorbing base is A, the thickness of the sound-absorbing projection is B, and the distance between the intake hole forming surface and the sound-absorbing upper end is C, then (A + B) / (A + B + C) is 0.44 and A / (A + B) is within the range of 0.20 to 0.

60.

3. A housing having an air intake port and an exhaust port formed therein, A centrifugal blower is provided inside the aforementioned housing and has an intake port formed therein, The sound-absorbing member provided on the inner surface of the aforementioned housing and Equipped with, The centrifugal blower generates an airflow that flows from the air intake port through the intake hole to the exhaust port, An internal air passage is formed inside the housing that guides the airflow from the air intake to the intake hole. The sound-absorbing member has a reference direction along the inner surface of the housing and a cross-sectional irregular section which is a specific section in the reference direction. The intake port is located at a position away from the air intake port in the reference direction, The sound-absorbing member has a sound-absorbing exposed surface that is exposed to the air passage inside the housing. The sound-absorbing exposed surface has a sound-absorbing upper end formed in the section with the irregular cross-sectional shape. At least a portion of the sound-absorbing upper end faces the intake hole, In the aforementioned section with an irregular cross-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 is greater than the thickness of the sound-absorbing member at a position away from the sound-absorbing upper end. The sound-absorbing member has a sound-absorbing base portion with a projection-forming surface formed toward the air passage inside the housing, and a sound-absorbing projection portion that protrudes from the projection-forming surface toward the air passage inside the housing in the section with an irregular cross-sectional shape, The cross-sectional shape of the sound-absorbing projection in a plane perpendicular to the aforementioned reference direction is triangular. A blower in which the ridge of the sound-absorbing projection facing the air passage inside the housing is the sound-absorbing upper end.

4. A housing having an air intake port and an exhaust port formed therein, A centrifugal blower is provided inside the aforementioned housing and has an intake port formed therein, The sound-absorbing member provided on the inner surface of the aforementioned housing and Equipped with, The centrifugal blower generates an airflow that flows from the air intake port through the intake hole to the exhaust port, An internal air passage is formed inside the housing that guides the airflow from the air intake to the intake hole. The sound-absorbing member has a reference direction along the inner surface of the housing and a cross-sectional irregular section which is a specific section in the reference direction. The intake port is located at a position away from the air intake port in the reference direction, The sound-absorbing member has a sound-absorbing exposed surface that is exposed to the air passage inside the housing. The sound-absorbing exposed surface has a sound-absorbing upper end formed in the section with the irregular cross-sectional shape. At least a portion of the sound-absorbing upper end faces the intake hole, In the aforementioned section with an irregular cross-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 is greater than the thickness of the sound-absorbing member at a position away from the sound-absorbing upper end. The sound-absorbing member has a sound-absorbing base portion with a projection-forming surface formed toward the air passage inside the housing, and a sound-absorbing projection portion that protrudes from the projection-forming surface toward the air passage inside the housing in the section with an irregular cross-sectional shape, The shape of the sound-absorbing projection is conical, with its apex facing the air passage inside the housing. A blower device in which the sound-absorbing upper end portion, including the vertex, is formed on the sound-absorbing exposed surface.

Images