JP5640928B2 - Aerodynamic sound reduction device - Google Patents

Description

  The present invention relates to an aerodynamic sound reduction device that reduces aerodynamic sound generated by airflow disturbance.

  In Patent Documents 1 and 2, in order to reduce the aerodynamic noise generated from the air-conditioning and cooling air blower, a member for reducing pressure fluctuation (hereinafter sometimes referred to as “reducing member”) is provided on the object surface. . For example, a configuration in which a feather-like or columnar protrusion or a fur-like fibrous member is provided as the reducing member is disclosed.

Japanese Patent Laid-Open No. 7-225048 JP 2006-159924 A

  As described above, in the prior art, a reduction member is provided to reduce aerodynamic noise. However, when the reduction member is a protrusion and a protrusion is partially provided, the turbulence of the air current is near the boundary of the presence or absence of the protrusion. May concentrate. There is a problem that the boundary between the presence or absence of such protrusions becomes a new sound source and a noise reduction effect cannot be sufficiently obtained.

  Accordingly, the present invention has been made in view of the above-described problems, and an object thereof is to provide an aerodynamic sound reduction device that can reduce the turbulence of the airflow due to the presence or absence of protrusions.

  The present invention employs the following technical means in order to achieve the aforementioned object.

The invention according to claim 1 is an aerodynamic sound reducing device provided in a passage member (11) forming a passage (13, 22, 25) through which air flows.
Including a plurality of protrusions (40) provided on the wall surface so as to protrude from a part of the wall surface (11a) of the passage member;
The plurality of protrusions are arranged at intervals on the wall surface (11a) of the passage member (11) so as to allow air to flow between the protrusions at a portion that changes the air flow direction .
The aerodynamics characterized in that the protrusions provided in a part of the portion where the plurality of protrusions are provided are at least different in height from the protrusions around the protrusions on the upstream side or the downstream side of the air flow. It is a sound reduction device.

According to the first aspect of the present invention, some of the protrusions are different in shape from the peripheral protrusions, or the protrusion intervals are different. When the protrusion is provided, the air current is disturbed at an unspecified position in the portion where the protrusion is provided. Such turbulence in airflow tends to increase when the shape and interval of the protrusions are constant. Therefore, by making the shape of the protrusion different and making the shape of the protrusion non-uniform, the position of the disturbance newly generated by the protrusion can be dispersed compared to the case where the shape of the protrusion is uniform. . Therefore, it is possible to suppress the turbulence of the airflow near the wall surface by the protrusions, reduce the turbulence newly generated by the protrusions, and obtain a sufficient noise reduction effect.
According to the invention, some of the plurality of protrusions are at least different in height from the surrounding protrusions. Therefore, the height of the protrusion is made uneven. As a result, for example, if the height is uneven in the projection group, the position where the turbulence of the air current is large is dispersed in the height direction, so that the turbulence in the entire air flow can be reduced and a sufficient noise reduction effect can be obtained. Can do.
The invention according to claim 2 is characterized in that a part of the plurality of protrusions is different in diameter and / or distance from the surrounding protrusions.
According to the invention described in claim 2, at least one of the diameter and the interval of the protrusions is made non-uniform. As a result, since the positions where the turbulence of the airflow is large are dispersed, the turbulence in the entire air flow can be reduced, and a sufficient noise reduction effect can be obtained.

Moreover, in invention of Claim 3 , several protrusion is provided in the site | part where air flows along a wall surface,
Some protrusions located on the upstream side of the air flow among the plurality of protrusions are characterized in that the height of the protrusion is larger, the diameter is larger, or the interval is smaller toward the downstream side of the air flow.

According to the third aspect of the present invention, among the plurality of protrusions, some of the protrusions located on the upstream side of the air flow have a protrusion height, diameter, or spacing that increases toward the downstream side of the air flow. small. Therefore, the resistance can be gradually increased from the upstream to the downstream of the air flow. As a result, it is possible to relieve the flow that has separated and flown backward due to the air flow, and it is possible to reduce the newly generated disturbance due to the concentration of the disturbance near the start position of the protrusion, so that a sufficient noise reduction effect can be obtained.

Furthermore, in invention of Claim 4 , several protrusion is provided in the site | part where air flows along a wall surface,
Some protrusions located on the downstream side of the air flow among the plurality of protrusions are characterized in that the height of the protrusion is smaller, the diameter is smaller, or the interval is larger as the air flow is further downstream.

According to the fourth aspect of the present invention, among the plurality of protrusions, some of the protrusions located on the downstream side of the air flow have a protrusion height, a diameter that is smaller, or an interval closer to the downstream of the air flow. large. Accordingly, the resistance to the air flow can be gradually lowered from the upstream toward the downstream. As a result, it is possible to reduce the newly generated disturbance due to the concentration of the disturbance near the end position of the protrusion, and to obtain a sufficient noise reduction effect.

Furthermore, in the invention according to claim 5, each of the plurality of protrusions has a cross-sectional shape in which the length in the air flow direction is larger than the width in the width direction perpendicular to the flow direction,
Some protrusions of the plurality of protrusions are different from the surrounding protrusions in intervals.

  According to the invention described in claim 5, each of the plurality of protrusions has a cross-sectional shape in which the length dimension in the air flow direction is larger than the width dimension in the width direction orthogonal to the flow direction. Some protrusions have different protrusion intervals. Therefore, each protrusion is arranged so as to extend in the air flow direction, and the positions of the protrusions are made non-uniform. Therefore, when using long projections, which are advantageous in terms of ease of processing by molding, by making the projection direction parallel to the flow of air flow, turbulence concentrates at the position where the flow collides with the projection and newly generated disturbance And a sufficient noise reduction effect can be obtained.

Further, in the invention according to claim 6, each of the plurality of protrusions has a cross-sectional shape in which a preset length dimension in the first direction is larger than a width dimension in the second direction orthogonal to the first direction,
Some protrusions out of the plurality of protrusions are characterized in that the direction in which the first direction extends differs from the direction in which the surrounding protrusions extend in the first direction.

  According to the invention of claim 6, each of the plurality of protrusions has a cross-sectional shape in which the length dimension in the first direction set in advance is larger than the width dimension in the second direction orthogonal to the first direction, Some protrusions of the plurality of protrusions are different from surrounding protrusions in the extending direction in the first direction. Therefore, for example, when the airflow path changes depending on the blowing mode as in a vehicle air conditioner, the turbulence can be prevented from being concentrated in any direction, and sufficient noise can be prevented. A reduction effect can be obtained.

  In addition, the code | symbol in the bracket | parenthesis of each above-mentioned means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

It is a schematic diagram which shows schematic structure of the vehicle air conditioner 10 and the air blower 60. FIG. It is sectional drawing which shows the air blower. 1 is a schematic diagram showing a schematic configuration of a vehicle air conditioner 10. FIG. 1 is a cross-sectional view for explaining a configuration of a vehicle air conditioner 10. FIG. 4 is a perspective view showing a first example of a plurality of protrusions 40. FIG. 3 is a side view showing a first example of a protrusion 40. FIG. It is a side view which shows the conventional protrusion 40Z as a comparative example. 5 is a side view showing a second example of the protrusion 40. FIG. It is a side view which shows the conventional protrusion 40Z as a comparative example. 6 is a graph showing the turbulence of the airflow of the third example of the protrusion 40. It is a graph which shows disturbance of the air current of the conventional protrusion 40. FIG. 7 is a plan view showing a fourth example of the protrusion 40. FIG. It is a top view which shows the conventional protrusion 40Z as a comparative example. It is a top view which shows protrusion 40A of this embodiment. It is a top view which shows the conventional protrusion 40Z as a comparative example. It is a top view which shows the conventional protrusion 40Z as a comparative example.

  Hereinafter, a plurality of embodiments for carrying out the present invention will be described with reference to the drawings. In some embodiments, portions corresponding to the matters described in the preceding embodiments may be given the same reference numerals, or one letter may be added to the preceding reference numerals, and overlapping descriptions may be omitted. In addition, when a part of the configuration is described in each embodiment, the other parts of the configuration are the same as those of the embodiment described in advance. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination does not hinder the combination.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram showing a schematic configuration of the vehicle air conditioner 10 and the blower 60. FIG. 2 is a cross-sectional view showing the blower 60. FIG. 3 is a schematic diagram showing a schematic configuration of the vehicle air conditioner 10. The vehicle air conditioner 10 is an apparatus capable of performing an air conditioning operation in a vehicle interior.

  The vehicle air conditioner 10 has an outer shell made up of an air conditioning case 11, and roughly includes a blower unit and an air conditioning unit. The air conditioning case 11 is disposed on the back side of the instrument panel 12 in front of the vehicle interior. The air conditioning case 11 has a function as a passage member that forms a passage through which air flows inward. The air conditioning case 11 includes a plurality of case members, and is a resin molded product such as polypropylene, for example. The plurality of case members are integrally coupled by fastening means such as metal springs and screws to form the air conditioning case 11.

  Further, the vehicle air conditioner 10 is a device that supplies air temperature-controlled from the left and right outlets toward the passenger compartment, and the air conditioning setting can be varied independently on the driver side and the passenger side, so-called Realizes independent left and right temperature control. An intermediate partition plate 14 is provided in the air conditioning case 11 of the vehicle air conditioner 10 so as to prevent mixing of the left and right separately ventilated air. It is divided into two ventilation paths.

  The blower unit includes a blower 60 for blowing air inside or outside the vehicle compartment to the air conditioning unit, and the blower outlet of the blower 60 is connected to the blower passage 13 leading to the inlet of the air conditioning unit. The blower 60 includes a centrifugal multiblade fan 61 and a motor 64 that drives the fan. The periphery of the centrifugal multiblade fan 61 is surrounded by a scroll casing 62, and the blower passage 13 is formed by a duct extending in the centrifugal direction of the centrifugal multiblade fan 61. Communicated with.

  The scroll casing 62 is a spiral member that houses the centrifugal multiblade fan 61 and that forms a passage for air blown out from the centrifugal multiblade fan 61. A wall surface 62b of the scroll casing 62 has a nose portion 62a. The nose portion 62a is a portion where the winding start side and the winding end side of the scroll casing 62 overlap, and is a winding start side portion. In the nose part 62a, the air upstream side and the air downstream communicate with each other through a slight gap.

  The air-conditioning unit includes an evaporator 20 that is provided to cover the entire air passage 13, a heater core 21 that heats air that has passed through the evaporator 20, a cold air passage 22, an air mix door 23, and a differential mix door 24. The air-conditioning case 11 includes a hot air passage 25, an air mix chamber 26 in a space where hot air and cold air are mixed, a defroster door 27, a face door 28, a foot door 29, and a rear door 30. Of the inside. Further, the air conditioning case 11 is formed with a plurality of air outlets 31 to 34 on the downstream side of the cold air passage 22 and the hot air passage 25, and here, a defroster air outlet 31 which is an example of the air outlet of the air conditioning case 11. A face outlet 32, a foot outlet 33, a first rear outlet 34, and a second rear outlet 35 are provided.

  The defroster outlet 31 is located in the upper part of the air conditioning case 11 on the vehicle front side. A defroster indoor air outlet 31a, which is one of the indoor air outlets, is provided in the vehicle front portion of the instrument panel 12 near the front window glass 12a. The defroster air outlet 31 and the defroster indoor air outlet 31a are connected to each other by a defroster duct 31b so that the conditioned air runs along the indoor side surface of the front window glass 12a and the like in order to reduce the degree of fogging. The defroster outlet 31 is controlled to open and close by a defroster door 27.

  The face outlet 32 is located on the vehicle rear side of the defroster outlet 31 at the top of the air conditioning case 11. A face indoor outlet 32a, which is one of the indoor outlets exposed in the vehicle interior, is provided on the front surface of the instrument panel 12 on the vehicle rear side. The face air outlet 32 and the face indoor air outlet 32a are connected to each other by a face duct 32b in order to blow air conditioned air toward the upper body of the passengers in the driver seat and the passenger seat. The face outlet 32 is controlled to open and close by the face door 28.

  The rear outlets 34 and 35 are located on the vehicle rear side below the air conditioning case 11. The rear seat is provided with a rear indoor air outlet (not shown) which is one of the indoor air outlets. The rear air outlets 34 and 35 and the rear indoor air outlet are connected by a rear duct 34b in order to blow air-conditioned air toward the rear seat. The rear blowout ports 34 and 35 are controlled to be opened and closed by the rear door 30 in the opening cross-sectional area. When the first rear outlet 34 is opened by the rear door 30, the air heated by the heater core 21 flows through the passage in the rear duct 34b, and the second rear outlet 35 is opened. In this case, the air cooled by the evaporator 20 flows through the passage in the rear duct 34b.

  The foot outlet 33 is located below the face outlet 32 above the air conditioning case 11. A foot indoor air outlet (not shown), which is one of the indoor air outlets, is provided at the foot of the passenger. The foot air outlet 33 and the foot indoor air outlet are connected to each other by a foot duct (not shown) in order to blow conditioned air toward the feet of the passengers in the driver seat and the passenger seat. The foot outlet 33 is controlled to be opened and closed by the foot door 29 at the opening cross-sectional area.

  The air outlets 31 to 35 are bilaterally symmetric about a passage partition wall (not shown) that bisects the inside of the air conditioning case 11 in the left-right direction of the vehicle, and are provided on both the left and right sides of the driver seat and the passenger seat of the vehicle. It is arranged to be able to supply conditioned air. In addition, the conditioned air blown out from each of the outlets 31 to 35 is supplied to a predetermined indoor blowing portion in the passenger compartment through the connected ducts 31b, 32b, and 34b.

  Each of the defroster door 27, the face door 28, and the foot door 29 is a one-side supported plate-like door having a rotating shaft and a flat door plate. The rear door 30 has a rotating shaft and a flat door plate, and is a single-sided support type door that circularly moves the door plate. The operations of the blower 60, the air mix door 23, the differential mix door 24, the defroster door 27, the face door 28, the foot door 29 and the rear door 30 are controlled by a control device (not shown).

  The evaporator 20 is a cooling heat exchanger that is located, for example, on the vehicle front side of the air conditioning case 11 and that evaporates the low-temperature and low-pressure refrigerant decompressed by the expansion valve in the refrigeration cycle by receiving the air blown from the blower 60. And the blowing air which passes the circumference | surroundings of the tube through which a refrigerant | coolant flows is cooled, and cold wind is supplied to the downstream cold wind channel | path 22. FIG.

  The heater core 21 is a heat exchanger for heating that is located at the lower part of the vehicle rear side of the evaporator 20 and heat-exchanges the air flowing around by using the high-temperature cooling water of the traveling engine as heat source and heat exchange. The heater core 21 is disposed so as to partially block the passage on the downstream side in the air flow direction from the evaporator 20.

  The differential mix door 24 is a door that is located on the vehicle rear side with respect to the evaporator 20 and can open and close the cold air passage 22 that is a downstream passage through which the air that has passed through the evaporator 20 flows down. The air mix door 23 is a door that is located on the vehicle rear side of the evaporator 20 and can open and close the cold air passage 22 and the hot air passage 25 through which the air that has passed through the evaporator 20 flows down.

  The air mix door 23 and the differential mix door 24 adjust the ratio of the amount of warm air passing through the heater core 21 and the amount of cool air not passing through the heater core 21 according to the opening positions thereof, thereby adjusting the temperature of the conditioned air. . When the air mix door 23 and the differential mix door 24 are at the positions indicated by the solid lines in FIG. 3, it is the maximum cooling time, the hot air passage 25 is closed to completely shut off the air flow to the heater core 21, Provide air conditioning in the passenger compartment. The state shown in FIG. 3 is when the face blowing mode is set, and the air mix door 23, the differential mix door 24, the defroster door 27, the face door 28, the foot door 29, and the rear door. 30 is also set as the opening position for executing the mode.

  FIG. 4 is a cross-sectional view for explaining the configuration of the vehicle air conditioner 10, and shows a state where the opening position of the door is different from that in FIG. 3. When the air mix door 23 and the differential mix door 24 are in the positions shown in FIG. 4, it is during maximum heating, and the cool air passage 22 leading to the air mix chamber 26 is closed and all the air that has passed through the evaporator 20 flows to the heater core 21. To provide heating air to the passenger compartment.

  Further, when the air mix door 23 is at a position intermediate between the positions shown in FIGS. 3 and 4, both the cold air passage 22 and the hot air passage 25 are partially opened, and both the cold air and the hot air flow down. It mixes with the air mix chamber 26 provided in the upstream of each blower outlet, is blown out from the blower outlet opened after temperature control, passes through the inside of a duct, and is sent to an indoor blower outlet.

  The warm air passage 25 is formed to be inclined toward the front side of the vehicle and extend from the lower portion of the air conditioning case 11 toward the upper air mix chamber 26. The warm air passage 25 has a width dimension across the entire vehicle left-right direction of the air conditioning case 11, and the width dimension is larger than the dimension in the vehicle front-rear direction. That is, the warm air passage 25 is a flat passage that is thin in the front-rear direction, horizontally long, and long in the up-down direction.

  The face air outlet 32 and the defroster air outlet 31 are openings facing the air mix chamber 26. The first rear outlet 34 is an opening facing the warm air passage 25. The second rear outlet 35 is an opening through which a cold air that does not pass through the heater core 21 is blown from the downstream side of the evaporator 20, facing a passage extending to a position below the heater core 21. Therefore, when the rear door 30 is at the position indicated by the solid line in FIG. 3, the first rear outlet 34 is closed and cold air is blown out from the second rear outlet 35. When the rear door 30 is at the position indicated by the solid line in FIG. 4, the second rear outlet 35 is closed and hot air is blown out from the first rear outlet 34.

  The vehicle air conditioner 10 of this embodiment is provided with an aerodynamic sound reduction device for reducing aerodynamic noise. The aerodynamic sound reduction device includes a plurality of protrusions 40. The plurality of protrusions 40 are provided at predetermined portions of at least a part of the wall surface 62 b of the scroll casing 62 and the inner wall 11 b of the air conditioning case 11. A plurality of protrusions 40 are provided so as to protrude from a predetermined location. FIG. 5 is a perspective view showing a first example of the plurality of protrusions 40. When the plurality of protrusions 40 are provided on the wall surface 62b of the scroll casing 62 and the wall surface 11a of the air conditioning case 11, for example, the plurality of protrusions 40 are integrally provided on the wall surface 11a. In this embodiment, the material of the scroll casing 62 and the air conditioning case 11 and the protrusion 40 is the same, and each case member and the protrusion 40 are integrally formed by injection molding. Similarly, when a plurality of protrusions 40 are provided on each door, they are integrally provided.

  Next, the place where the protrusion 40 is provided will be described. The plurality of protrusions 40 are provided at a change portion that changes the flow of air, for example. A change part is a part which has the surface where an airflow collides in order for the shape of the wall surface 11a to change and to change the flow direction of air. The change in the shape of the wall surface 11a is a portion where the wall surface 11a is not linear along the air flow, and the shape of the wall surface 11a is changed because the passage is bent, curved, enlarged or reduced, for example. The changed portion is a portion having an angle of attack at which the air volume does not decrease due to passage resistance. For example, the changed portion has an angle of attack with respect to the air flow direction of 30 degrees or more, preferably 40 degrees or more, and more preferably 60 degrees or more.

  The plurality of protrusions 40 are schematically shown in FIG. 1 and hatched in FIGS. 2 to 4, and the wall surface 62 b of the scroll casing 62, the wall surface 11 a of the air conditioning case 11, and the door plate constituting each door. Provided on at least one of the two surfaces. Hereinafter, the door plate may be simply referred to as a door.

As shown in FIG. 1, one installation site on the wall surface 62b of the scroll casing 62 is a nose portion 62a. The nose portion 62a is a portion where the airflow direction is unstable and the direction of the airflow and the magnitude of the flow velocity change every moment. Moreover, the other installation site | part 63 in the wall surface 62b of the scroll casing 62 is a part which changes the flow direction of the inhaled air from a suction direction to a centrifugal direction, as shown in FIG. The other installation part 63 is a part of the surface opposite to the suction side of the wall surface 62 b of the scroll casing 62. When the blower 60 is operated, the airflow introduced from the suction side is increased in pressure between the blades of the centrifugal multiblade fan 61 and pushed out to the blade outer periphery (centrifugal direction), and is blown along the scroll casing 62 toward the outlet. The The other installation site 63 is a site where the airflow introduced collides with the leading edge of the wing and the airflow released from the wing collides with the first installation site 41 on the wall surface 11a of the air conditioning case 11. It is a position on the downstream side and facing the evaporator 20. The second installation site 42 on the wall surface 11 a of the air conditioning case 11 is a position on the downstream side of the heater core 21 and facing the heater core 21. The third installation part 43 in the wall surface 11 a of the air conditioning case 11 is a part where air is blown into the air conditioning case 11 from the blower 60. Accordingly, the third installation part 43 is a part that changes the air flow so that the air is directed toward the evaporator 20 among the parts that constitute the passage leading to the scroll casing 62 on the upstream side of the evaporator 20.

  Further, among the doors, the face door 28 and the rear door 30 are provided with protrusions 40 on the surface that becomes the inside of the air conditioning case 11 when the doors are closed. Accordingly, the face door 28 and the guide are provided with a plurality of protrusions 40 on the surface located inside the air conditioning case 11 when in the closed state. Further, as shown in FIG. 3, the rear door 30 is provided with a plurality of protrusions 40 on the surface facing the heater core 21 when the first rear outlet 34 is closed. The air mix door 23 is provided with a plurality of protrusions 40 on both sides.

  Further, although not shown, guides (not shown) for guiding air to the doors are provided around the face door 28 and around the rear door 30. Of the wall surfaces of the guide, projections 40 are provided on a surface that guides air in a direction toward at least each door when air collides. Further, a rib (not shown) is provided on the wall surface of the air mix chamber 26. The rib is for adjusting the mixing ratio of cold air and hot air. Since such a rib also constitutes a part of the wall surface 11a of the air conditioning case 11 and is a portion where air collides, a plurality of protrusions 40 are also provided on the surface of the rib. The rib for adjusting the mixing ratio includes a rib for avoiding mixing of cold air and hot air (setting the mixing ratio to 0).

  In the air conditioning case 11, since the protrusions 40 are provided at the above-described portions, for example, during cooling shown in FIG. 3, a part of the airflow that has passed through the evaporator 20 collides with the air mix door 23 as indicated by a broken line. The air flow direction is changed in the direction toward the face outlet 32. Further, the other part of the airflow that has passed through the evaporator 20 collides with the first installation site 41, and the airflow direction is changed in the direction toward the rear duct 34b. Further, since the protrusions 40 provided on the back surfaces of the face door 28 and the air mix door 23 are not in contact with the airflow, the protrusions 40 are portions that do not cause a decrease in the air volume.

  4, a part of the airflow that has passed through the evaporator 20 collides with the back surface of the air mix door 23, and the airflow direction is changed in the direction toward the heater core 21, as indicated by a broken line. The airflow that has passed through the heater core 21 collides with the second installation part 42, further collides with the inner surface of the face door 28, and the airflow direction is changed in the direction toward the foot door 29. Further, the other part of the airflow that has passed through the evaporator 20 collides with the rear door 30, and the airflow direction is changed so as to go to the rear indoor outlet. Further, since the protrusion 40 provided on the surface of the air mix door 23 and the first installation site 41 is not in contact with the airflow, the protrusion 40 does not cause a decrease in the air volume.

  Next, the shape of the protrusion 40 will be described. FIG. 6 is a side view showing a first example of the protrusion 40. FIG. 7 is a side view showing a conventional protrusion 40Z as a comparative example. 6 and 7, the diameter of the protrusion 40 is simplified and shown in a linear shape. A protrusion 40 shown in FIG. 6 is a protrusion 40 provided on the air mix door 23. Each protrusion 40 is formed in a cylindrical shape. The plurality of protrusions 40 are formed so as to protrude vertically from the surface of the air mix door 23.

  Some of the plurality of protrusions 40 are different in shape from the surrounding protrusions 40. The shape of the protrusion 40 includes the outer shape, height, diameter, and the like of the protrusion 40. As shown in FIG. 6, in some of the plurality of protrusions 40, the height of the protrusion 40 increases from the upstream side of the air flow to the center downstream of the air flow. Further, among the plurality of protrusions 40, some of the protrusions 40 have a height that decreases as the air flows downstream from the center. In other words, the plurality of protrusions 40 are formed in a mountain shape in which the central protrusion 40 in the air flow direction is high, the center is high, and the skirt is low. On the other hand, as shown in FIG. 7, the protrusion 40Z of the comparative example has a uniform height.

  When the air flow direction is changed, a flow along the surface of the air mix door 23 is generated. The height of a part of the projection 40 provided on the air mix door 23 is gradually increased from the upstream toward the downstream. 6 and 7 show a state in which air is flowing from left to right as indicated by arrows. Thereby, the air resistance can be gradually increased from the upstream toward the downstream. In the comparative example of FIG. 7, the disturbance is concentrated near the start position of the protrusion 40Z, and a new disturbance is generated. On the other hand, as shown in FIG. 6, the disturbance near the start position (upstream position) of the protrusion 40 can be reduced, and a sufficient noise reduction effect can be obtained.

  Further, the height of the protrusion 40 is gradually decreased from the upstream toward the downstream. Thereby, the air resistance can be gradually lowered from the upstream toward the downstream. In the comparative example of FIG. 7, the disturbance is concentrated near the end position of the protrusion 40Z, and the disturbance is newly generated. On the other hand, as shown in FIG. 6, the disturbance near the end position of the protrusion 40 can be reduced, and a sufficient noise reduction effect can be obtained.

  FIG. 8 is a side view showing a second example of the protrusion 40. FIG. 9 is a side view showing a conventional protrusion 40Z as a comparative example. The protrusion 40 shown in FIG. 8 is a protrusion 40 provided at a portion where the downstream side is inclined downward. 8 and 9, the diameter of the protrusion 40 is simplified and shown in a linear shape. 8 and 9, air is flowing from left to right as indicated by arrows.

  As shown in FIG. 8, among the plurality of protrusions 40, some of the protrusions 40 on the downstream side have a height that decreases as the air flows downstream. On the other hand, as shown in FIG. 7, the protrusion 40Z of the comparative example has a uniform height.

  For example, at the position where the airflow is separated at the downstream end of the air mix door 23, the height is lowered toward the downstream. In the comparative example of FIG. 9, a flow is generated in which the airflow is separated and backflowed. On the other hand, as shown in FIG. 8, the backflow can be mitigated by the low protrusion 40. Therefore, disturbances newly generated due to disturbances concentrated near the end position of the protrusion 40 can be reduced, and a sufficient noise reduction effect can be obtained.

  FIG. 10 is a graph showing the turbulence of the airflow of the third example of the protrusion 40. FIG. 11 is a graph showing the turbulence of the airflow of the conventional protrusion 40. In FIG. 10 and FIG. 11, the state is virtually shown from the side surface of the projection 40, and the positional relationship of the projection 40 and the relationship between the graphs are shown. The protrusion 40 shown in FIG. 10 is the protrusion 40 provided at the first installation site 41. 10 and 11 show a state in which air is flowing from left to right as indicated by arrows. At least some of the plurality of protrusions 40 are formed to have a height different from that of the adjacent protrusions 40. In this example, the heights of the protrusions 40 adjacent to each other in the flow direction are different from each other. In other words, the height of the protrusion 40 is not uniform.

  In the comparative example of FIG. 11, since the height of the protrusion 40 </ b> Z is uniform, the value of the turbulence of airflow (vorticity variable) is large at the apex of the protrusion 40. On the other hand, as shown in FIG. 10, if the height is uneven in the protrusion 40, the position where the turbulence of the air current is large is dispersed in the height direction, so that the turbulence in the entire flow can be reduced and sufficient noise is obtained. A reduction effect can be obtained.

  FIG. 12 is a plan view showing a fourth example of the protrusion 40. FIG. 13 is a plan view showing a conventional protrusion 40Z as a comparative example. A protrusion 40 shown in FIG. 12 is a protrusion 40 provided on the air mix door 23. 12 and 13 show a state in which air is flowing from left to right as indicated by arrows. At least some of the plurality of protrusions 40 are formed such that the distance between adjacent protrusions 40 is different from the distance between other protrusions 40 arranged around the protrusions 40. In other words, the interval between the protrusions 40 is not uniform.

  In the comparative example of FIG. 13, since the interval between the adjacent protrusions 40Z is uniform, a flow that passes through the interval between the protrusions 40Z is generated, and the turbulence of the airflow cannot be sufficiently suppressed. On the other hand, as shown in FIG. 12, when the intervals of the protrusions 40 are made non-uniform, it is possible to prevent a flow that passes through the intervals and to suppress the turbulence of the airflow.

  As described above, in the aerodynamic sound reducing device in the vehicle air conditioner 10 of the present embodiment, some of the protrusions 40 out of the plurality of protrusions 40 have different shapes from the surrounding protrusions 40 or are provided in part. The interval between the protrusions 40 is different from the interval between the surrounding protrusions 40. Therefore, the noise reduction effect is enhanced by installing a plurality of unevenly shaped protrusions 40 or protrusions 40 at uneven positions at positions where sound is generated in contact with the turbulent airflow. By making the shape of some of the protrusions 40 different and making the shape of the protrusions 40 non-uniform, it is possible to disperse the positions of disturbances newly generated by the protrusions 40. Therefore, the projection 40 can suppress the turbulence of the airflow near the wall surface, reduce the turbulence newly generated by the projection 40, and obtain a sufficient noise reduction effect.

  In the present embodiment, among the plurality of protrusions 40, some of the protrusions 40 have the protrusions 40 having a height higher toward the downstream side of the air flow. Therefore, the resistance can be gradually increased from the upstream to the downstream of the air flow. As a result, it is possible to relieve the flow that is separated by the air flow and flows backward, and the disturbance generated by the concentration of disturbance near the start position of the protrusion 40 can be reduced, so that a sufficient noise reduction effect can be obtained. Further, the height of the protrusions 40 is not limited to be large, and the diameter of the protrusions 40 may be large or the interval may be small, or these may be combined.

  Furthermore, in the present embodiment, some of the plurality of protrusions 40 are such that the protrusion 40 has a smaller height toward the downstream side of the air flow. Accordingly, the resistance to the air flow can be gradually lowered from the upstream toward the downstream. As a result, disturbances newly concentrated due to disturbances concentrated near the end position of the protrusion 40 can be reduced, and a sufficient noise reduction effect can be obtained. In addition, the height of the protrusion 40 is not limited to be small, and the diameter of the protrusion 40 may be small or the interval may be large, or these may be combined.

  In the present embodiment, some of the plurality of protrusions 40 have different heights or intervals compared to the surrounding protrusions 40. Therefore, for example, at least one of the heights or intervals of the adjacent protrusions 40 is nonuniform. Thereby, for example, if the height is uneven in the projections 40 group, the position where the turbulence of the air current is large is dispersed in the height direction, so that the turbulence in the entire air flow can be reduced, and a sufficient noise reduction effect is obtained. be able to. Further, the height and the interval of the protrusions 40 are not limited, and the diameter and the outer shape of the protrusions 40 may be combined.

  For example, the shape of the protrusion 40 may be a long cylinder instead of a cylinder, so that the long side of the protrusion 40 is parallel to the flow of the airflow, and the position of the protrusion 40 may be non-uniform. Since the strength is increased when a long cylindrical strip is used, it is easy to process by molding. By making the direction of the projection 40 parallel to the flow of the airflow, the disturbance is newly generated due to the concentration of disturbance at the position where the flow hits the projection 40. And a sufficient noise reduction effect can be obtained.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 14 is a plan view showing the protrusion 40A of the present embodiment. FIG. 15 is a plan view showing a conventional protrusion 40Z as a comparative example. FIG. 16 is a plan view showing a conventional protrusion 40Z as a comparative example. 15 and 16 are different from each other in the flow direction of the flowing air.

  The long cylindrical shape of the outer shape of the protrusion 40A includes an oval shape and an elliptical column shape. The protrusion 40A extends in a predetermined first direction. Further, the direction (direction) in which the first direction of each protrusion 40A extends is not uniform but non-uniform as shown in FIG. On the other hand, in the comparative example, the direction is uniform.

  Each of the plurality of protrusions 40A has a width dimension in the second direction (width direction) in which the length dimension in the first direction (length direction) (the dimension in the left-right direction in FIG. 15) is orthogonal to the first direction in the cross-sectional shape. It is larger than W (length in the vertical direction in FIG. 15). The cross-sectional shape is a cross-sectional shape when the protrusion 40A is cut along a virtual plane parallel to the wall surface 11a. Accordingly, the cross-sectional shape is the same as the shape when viewed toward the wall surface 11a when the cross-sectional shape of the protrusion 40A is a columnar shape.

  The protrusion 40A shown in FIG. 12 is a protrusion 40A provided in the air mix chamber 26, for example. The air direction in the air mix chamber 26 differs greatly depending on whether the airflow is blown from the face outlet 32 during cooling or the airflow is blown out from the defroster outlet 31 during dehumidification.

  In the comparative example of FIG. 15 and FIG. 16, since the direction is uniform, the air flow toward the right shown in FIG. 15 is effective, but in the case of the air flow upward shown in FIG. The disturbance is concentrated and the noise reduction effect cannot be obtained sufficiently. On the other hand, as shown in FIG. 14, when the directions are not uniform, it is possible to prevent disturbances from being concentrated in the flow in any direction, and a sufficient noise reduction effect can be obtained.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the first embodiment and the second embodiment described above, the plurality of protrusions 40 have a columnar shape or a long columnar shape, but are not limited to such a shape. For example, the cross-sectional shape may be a rhombus extending in the first direction or a rectangular shape. Moreover, the shape which diameter-reduces in a taper shape toward a front-end | tip may be sufficient. Each protrusion 40 may be inclined with respect to the bottom surface (wall surface).

  In the first embodiment described above, the air noise reduction device is provided in the vehicle air conditioner 10, but is not limited to the vehicle air conditioner 10, and may be other than the air conditioner, for example, cooling for equipment cooling. It can be applied to an air blower.

DESCRIPTION OF SYMBOLS 10 ... Vehicle air conditioner 11 ... Air-conditioning case (passage member)
11a ... Wall 13 ... Blower passage (passage)
20 ... Evaporator 21 ... Heater core 22 ... Cool air passage (passage)
23 ... Air mix door 25 ... Warm air passage (passage)
26 ... Air mix chamber 28 ... Face door 29 ... Foot door 30 ... Rear door 40, 40A ... Projection 60 ... Blower 62 ... Scroll casing

Claims (6)

An aerodynamic sound reducing device provided in a passage member (11) forming a passage (13, 22, 25) through which air flows,
A plurality of protrusions (40) provided on the wall surface so as to protrude from a part of the wall surface (11a) of the passage member;
The plurality of protrusions are arranged at intervals on the wall surface (11a) of the passage member (11) to change the air flow direction so that air flows between the protrusions.
Protrusions provided in a part of the portion where the plurality of protrusions are provided are at least different in height from the protrusions around the partial protrusions and located upstream or downstream of the air flow. Aerodynamic sound reduction device.   2. The aerodynamic sound reduction device according to claim 1, wherein some of the plurality of protrusions are different in diameter and / or the distance from the surrounding protrusions. The plurality of protrusions are provided in a portion where the air flows along the wall surface,
The projections of some of the plurality of projections located on the upstream side of the air flow have a projection height, diameter, or spacing that is closer to the downstream side of the air flow. Item 3. The aerodynamic sound reduction device according to Item 2. The plurality of protrusions are provided in a portion where the air flows along the wall surface,
2. The protrusions of some of the plurality of protrusions that are located on the downstream side of the air flow have a protrusion height, a diameter that is smaller, or a gap that is closer to the downstream side of the air flow. The aerodynamic sound reduction apparatus as described in any one of -3. Each of the plurality of protrusions has a cross-sectional shape in which the length dimension in the air flow direction is larger than the width dimension in the width direction perpendicular to the flow direction,
5. The aerodynamic sound reduction device according to claim 1, wherein some of the plurality of protrusions are different in distance from the surrounding protrusions. Each of the plurality of protrusions has a cross-sectional shape in which a preset length dimension in the first direction is larger than a width dimension in the second direction orthogonal to the first direction,
5. The projection according to claim 1, wherein a part of the plurality of protrusions has a direction in which the first direction extends different from a direction in which the peripheral protrusions extend in the first direction. The aerodynamic sound reduction device described in 1.

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