JP3873913B2 - Centrifugal blower - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a centrifugal blower and is effective when applied to a blower of a vehicle air conditioner.
[0002]
[Prior art]
As is well known, the scroll casing of a centrifugal blower forms a spiral air flow path on the outer diameter side of the centrifugal multiblade fan, and the flow path extends from the winding start portion of the scroll casing, that is, from the nose portion to the winding end portion. The cross-sectional area is gradually increased, and the air blown out from the centrifugal multiblade fan is efficiently gathered to flow downstream.
[0003]
For this reason, as shown in FIG. 7, the optimal shape and dimensions of the scroll casing shape dimensions, that is, the increase rate of the cross-sectional area such as the spread angle and the flow path cross-sectional area vary depending on the air flow rate and the ventilation resistance.
[0004]
Therefore, conventionally, a spiral air flow path variable blade formed by a scroll casing is provided, and the flow path is made by swinging the variable blade in a direction parallel to the rotation axis of the centrifugal multiblade fan in accordance with the air flow rate. The cross-sectional area is changed (see, for example, Patent Document 1).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-161896
[Problems to be solved by the invention]
However, the invention described in Patent Document 1 employs a scroll casing having a constant spread angle from the beginning of winding of the scroll casing to the end of winding, and is provided with door means on the winding end side of the scroll casing. If the means is rotated, it will deviate greatly from the optimum flow path shape (scroll casing shape).
[0007]
In view of the above points, the present invention firstly provides a novel centrifugal blower different from the conventional one, and secondly, it aims to reduce blowing noise while improving the blowing efficiency.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a plurality of blades (71a) are provided around the rotating shaft, and the air sucked from the axial direction of the rotating shaft is radially outward. A centrifugal multi-blade fan (71) that blows out and a spiral air passage (72a) that houses the centrifugal multi-blade fan (71) and through which the air blown from the centrifugal multi-blade fan (71) flows And a scroll casing (72) in which the outer peripheral side inner wall radius (r) changes logarithmically in response to the winding angle (θ ). The outer peripheral side inner wall (73) of the scroll casing (72) The belt casing is fixed to the scroll casing (72) and the other end is fixed to the winding mechanism (74). The winding mechanism (74) winds up the outer peripheral inner wall (73). Rotary winding to adjust the amount Drive mechanism (74b, 74c) that translates the ram (74a) and the winding drum (74a) while rotating in the width direction of the outlet opening (72c) formed at the other end of the outer peripheral side inner wall (73). The winding mechanism (74) is adapted to adjust the winding amount in accordance with the ventilation resistance in the air flow path blown by the centrifugal multiblade fan (71). The outer peripheral side inner wall (73) is displaced by adjusting the take-off amount to change the expansion angle (n) of the substantially entire region from the winding start portion to the winding end portion of the scroll casing (72), and at the same time, the outlet The opening area of the opening (72c) is changed . In the present invention, the “width direction of the outlet opening (72c)” refers to a direction connecting the outer peripheral side end and the inner peripheral side end of the scroll casing (72) in the outlet opening (72c). That means.
[0009]
Thereby, blowing noise can be reduced while improving blowing efficiency.
[0010]
In the invention described in claim 2, the winding mechanism (74) increases the opening angle (n) as the draft resistance decreases, and simultaneously increases the opening area, and the spreading angle (n) as the draft resistance increases. The opening area is reduced at the same time as reducing the.
[0011]
In the third aspect of the invention, the drive mechanism (74b, 74c) includes a pinion (74b) provided on the take-up drum (74a) and a rack (74b) that meshes with the pinion (74b). It is characterized by this.
[0012]
The invention according to claim 4 is characterized in that at least the outer peripheral side inner wall (73) is provided with a sound absorbing material that attenuates vibrations of air to reduce noise.
[0013]
The invention according to claim 5 includes the centrifugal blower (7) according to any one of claims 1 to 4 and a blow mode switching device (18 to 20) for switching a blow mode of air blown into the room. An electronic control device (21) that is a vehicle air conditioner, determines ventilation resistance based on the operating state of the blowing mode switching device (18 to 20), and controls the winding mechanism (74) according to ventilation resistance. It is characterized by having .
[0014]
In invention of Claim 6, it has the centrifugal blower (7) as described in any one of Claim 1 thru | or 4, determines ventilation resistance based on the ventilation volume of a centrifugal blower (7) , It has an electronic control unit which controls a winding mechanism (74) according to ventilation resistance .
[0015]
In invention of Claim 7, it has the centrifugal blower (7) as described in any one of Claim 1 thru | or 4, and the blowing mode of the air blown out indoors and the ventilation volume of a centrifugal blower (7) out at least one a vehicle air-conditioning device for an automatic control system for controlling based on the target temperature (TAO) of air blown into the passenger compartment, to determine the flow resistance based on the target temperature (TAO), depending on the ventilation resistance An electronic control unit for controlling the winding mechanism (74) is provided.
[0016]
Incidentally, the reference numerals in parentheses of each means described above are an example showing the correspondence with the specific means described in the embodiments described later.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
In this embodiment, the centrifugal blower according to the present invention is applied to a vehicle air conditioner. FIG. 1 is a schematic diagram of the vehicle air conditioner 1 according to this embodiment.
[0018]
An air upstream side portion of the air-conditioning casing 2 that forms the air flow path is formed with an inside air suction port 3 for sucking in vehicle interior air and an outside air suction port 4 for sucking outside air. A suction port switching door 5 for selectively opening and closing the ports 3 and 4 is provided. The inlet switching door 5 is opened and closed by a driving means such as a servo motor or by manual operation.
[0019]
A filter (not shown) for removing dust in the air and a blower 7 according to the present embodiment are disposed on the downstream side of the air flow of the suction port switching door 5. The air sucked from 4 is blown toward the respective outlets 14, 15, 17 described later.
[0020]
Further, an evaporator 9 serving as a cooler for cooling the air blown into the room is disposed on the air downstream side of the blower 7, and all the air blown by the blower 7 passes through the evaporator 9. The evaporator 9 is a low pressure side heat exchanger of a vapor compression refrigerator that generates refrigeration capacity by evaporating the refrigerant.
[0021]
A heater 10 that heats the air blown into the room is disposed on the air downstream side of the evaporator 9, and the heater 10 heats the air using the cooling water of the engine 11 as a heat source. In addition, the air blower apparatus 7 shown by FIG. 1 is a schematic diagram, and details are mentioned later.
[0022]
The air conditioning casing 2 is formed with a bypass passage 12 that bypasses the heater core 10, and the air volume ratio between the air volume passing through the heater core 10 and the air volume passing through the bypass passage 12 is adjusted on the air upstream side of the heater core 10. Thus, an air mix door 13 for adjusting the temperature of the air blown into the vehicle compartment is provided.
[0023]
And in the most downstream site | part of the air-conditioning casing 2, the face blower outlet 14 for blowing off air-conditioning air to the passenger | crew's upper body, the foot blower outlet 15 for blowing air to a passenger | crew's passenger | crew's feet, windshield A defroster outlet 17 for blowing air toward the inner surface of 16 is formed.
[0024]
And the blowing mode switching doors 18, 19, and 20 for switching and controlling the blowing mode are disposed on the air upstream sides of the outlets 14, 15, and 17, respectively. Incidentally, these blow mode switching doors 18, 19, and 20 are opened and closed by a driving means such as a servo motor or by manual operation.
[0025]
In addition, as a blowing mode, the face mode which mainly blows air from the face blower outlet 14, the foot mode which mainly blows air from the foot blower outlet 15, the bi-level mode which blows air from the face blower outlet 14 and the foot blower outlet 15, In addition, there is a defroster mode in which air is mainly blown from the defroster outlet 17.
[0026]
Incidentally, in general, since the vehicle air conditioner requires a large air volume in the face mode in which air is blown out from the face air outlet 14, the ventilation resistance (pressure loss) in the face mode is different from that in the other air blowing modes (foot mode). And differential mode).
[0027]
Further, as shown in FIG. 2, the electronic control unit (ECU 21) detects an indoor air sensor that detects the temperature of the indoor air, an outdoor air sensor that detects the temperature of the outdoor air, and the air temperature immediately after passing through the evaporator 9. A detection signal from an air conditioning sensor 22 such as a post-evaporation sensor and a solar radiation sensor that detects the amount of solar radiation poured into the room, a desired indoor temperature set by the passenger, that is, an output from the operation panel 23, and the like are input.
[0028]
Then, the ECU 21 calculates a target temperature of the air blown into the room, that is, a target blowing temperature TAO according to a program stored in advance based on a signal input to the ECU 21, and the inlet switching door based on the target blowing temperature TAO. 5. The air mix door 13, the blow mode switching doors 18, 19, 20 and the blower 7, that is, the voltage applied to the electric motor for rotating the fan 71 or the number of rotations are controlled.
[0029]
Next, the blower 7 will be described in detail.
[0030]
As shown in FIG. 3, the blower 7 includes a centrifugal multiblade fan (hereinafter referred to as a fan) that has a large number of blades 71a around the rotation axis and blows out the air sucked in from the rotation axis direction. 71), an electric fan motor that is arranged on one end side in the rotation axis direction and serves as a driving means for rotating the fan 71, and a spiral air flow path 72a in which the fan 71 is housed and the air blown out from the fan 71 flows. It is comprised from the scroll casing 72 grade | etc., Which comprises.
[0031]
Here, the scroll casing 72 gradually increases in cross-sectional area from the winding start portion of the scroll casing 72, that is, from the nose portion 72b to the winding end portion, so that the air blown from the fan 71 is efficiently gathered and flows downstream. is doing. Specifically, the outer peripheral side inner wall radius r of the scroll casing 72 is gradually expanded in a logarithmic spiral function with respect to the winding angle θ measured from the nose portion 72b.
[0032]
Here, the logarithmic spiral function is expressed by the following Equation 1, and θ is an angle measured in the direction of fan rotation from the reference line connecting the center of the radius of curvature of the nose portion 72b and the rotation center of the fan 72. (Unit: radians), and ro is the inner radius on the outer circumference side of the reference line (θ = 0).
[0033]
[Expression 1]
r = ro · e (π / 180) n · θ
In the present embodiment, the outer peripheral side inner wall 73 of the scroll casing 72 is displaced in accordance with the ventilation resistance, that is, the air pressure in the air flow path 72a, and the abbreviated portion of the scroll casing 72 from the winding start portion to the winding end portion. The spread angle n of the entire region is changed in the range of 4 ° to 6 °.
[0034]
Incidentally, as is well known, the nose portion 72b is a portion where the winding start side and the winding end side of the scroll casing 72 overlap each other, and in this nose portion 72b, there is a slight gap between the air upstream side and the air downstream side (see FIG. (Not shown)).
[0035]
The outer peripheral side inner wall 73 is a movable wall, one end of which is fixed to the scroll casing 72, are those other end the winding mechanism 74 of the fixed strip spring shape, Ru good to the take-up mechanism 74 By adjusting the winding amount of the outer peripheral inner wall 73, the spread angle n is changed as shown in FIG.
[0036]
Further, as shown in FIG. 5, the outer peripheral side inner wall 73 is formed by embedding a metal wire 73 a such as a piano wire for generating spring characteristics in a flexible resin film-like member 73 b. The right end portion of the paper surface is fixed to the scroll casing 72, and the left end portion of the paper surface is fixed to the winding drum 74a (FIG. 3) of the winding mechanism 74.
[0037]
Further, as shown in FIG. 3, the take-up mechanism 74 engages with the take-up drum 74a, the pinion 74b of the take-up drum 74a, and moves the rack 74c to move while rotating the take-up drum 74a. The actuator, that is, the winding mechanism 74 is controlled by the ECU 21.
[0038]
Incidentally, the stopper guide 73c regulates the amount of displacement so that the displacement of the outer peripheral side inner wall 73 stops at the position where the spread angle n is minimized, and the position where the spread angle n is maximized is the outer periphery of the scroll casing 72. Regulated by side outer walls.
[0039]
Next, the characteristic operation and effect of the centrifugal blower 7 according to the present embodiment will be described.
[0040]
In the face mode, as described above, the ventilation resistance (pressure loss) is reduced and the air volume is increased as compared with the other blowing modes (foot mode and differential mode), and the air pressure (static pressure) in the air flow path 72a is increased. In order to decrease, the outer peripheral side inner wall 73 is displaced to a position where the spread angle n is maximized.
[0041]
On the other hand, in the foot mode and the differential mode, the ventilation resistance (pressure loss) increases and the air volume decreases and the air pressure (static pressure) in the air flow path 72a increases, so that the spread angle n is minimized. The outer peripheral side inner wall 73 is displaced to a position where
[0042]
Thereby, since the shape dimension of the scroll casing 72, that is, the increase rate of the cross-sectional area such as the expansion angle n and the cross-sectional area of the flow path can be optimized according to the air flow rate and the ventilation resistance, However, it is possible to reduce the blowing noise while improving the blowing efficiency.
[0043]
Incidentally, in the air conditioner that was experimentally studied based on this embodiment, it was possible to reduce the noise by about 3 dB regardless of the blowing mode, compared to the conventional type.
[0044]
(Second Embodiment)
In the present embodiment, as shown in FIG. 6, the outer peripheral side inner wall 73 is configured by a plurality of movable walls 73d arranged from the winding start side to the winding end side, and adjacent movable walls 73d partially overlap each other. In this state, each of the movable walls 73d is displaced along the link groove 73e to change the spread angle n.
[0045]
(Third embodiment)
In the above embodiment, but changes the divergence angle in accordance with the blowing mode, even blowout mode is constant, since the air volume is changed ventilation resistance changes, in this embodiment, to the fan motor The spread angle n increases as the applied voltage or rotational speed increases and the air flow rate increases. Conversely, the spread angle n decreases as the applied voltage or rotational speed to the fan motor decreases and the air flow rate decreases. There is .
[0046]
Specifically, when the target blowing temperature TAO decreases, the cooling operation is set to the face mode, and when the target blowing temperature TAO increases, the heating operation is set to the foot mode. Therefore, the target blowing temperature TAO is set to the first predetermined temperature. When the value is smaller than the value, the spread angle n is maximized. When the target blowing temperature TAO is larger than the second predetermined value larger than the first predetermined value, the spread angle n is minimized, and the target blowing temperature TAO is the first predetermined value and the second predetermined value. When the interval is between, the spread angle n is decreased in accordance with the increase in the target blowout temperature TAO.
[0047]
(Other embodiments)
In the above-described embodiment, the present invention is applied to the vehicle air conditioner, but the present invention is not limited to this.
[0048]
Further, for example, the divergence angle n may be changed by measuring the air pressure of the ventilation system from the blower 7 to the outlets 14, 15, 17 with a pressure sensor or the like.
[0049]
Further, noise can be further reduced by providing at least the outer peripheral side inner wall 73 with a sound absorbing material that attenuates air vibrations to reduce noise.
[0050]
Moreover, you may combine at least 2 embodiment among 1st, 3rd, 4th embodiment.
[0051]
Moreover, you may combine at least 2 embodiment among 2nd-4th embodiment.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an air conditioner according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing a control system of the air conditioner according to the embodiment of the present invention.
FIG. 3 is a perspective view of the blower according to the first embodiment of the present invention.
FIG. 4 is an operation explanatory diagram of the blower according to the first embodiment of the present invention.
FIG. 5 is a perspective view of an outer peripheral side inner wall according to the first embodiment of the present invention.
FIG. 6 is an explanatory diagram of a blower according to a second embodiment of the present invention.
FIG. 7 is a graph showing the relationship between air volume, noise, and pressure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Fan, 72 ... Scroll casing, 72c ... Outlet opening part,
73 ... inner wall (movable wall) on the outer peripheral side, 74 ... winding mechanism , 74a ... winding drum,
74b ... Pinion (drive mechanism), 74c ... Rack (drive mechanism) .

Claims (7)

A centrifugal multiblade fan (71) having a large number of blades (71a) around the rotation axis and blowing out the air sucked in from the axial direction of the rotation shaft toward the outside of the diameter;
The centrifugal multiblade fan (71) is housed to form a spiral air flow path (72a) through which the air blown from the centrifugal multiblade fan (71) flows, and the outer peripheral inner wall radius (r) is A scroll casing (72) that changes logarithmically in response to the winding angle (θ),
The outer peripheral side inner wall (73) of the scroll casing (72) has a strip spring shape in which one end side is fixed to the scroll casing (72) and the other end side is fixed to the winding mechanism (74). ,
The winding mechanism (74) includes a rotary winding drum (74a) for adjusting a winding amount of the outer peripheral side inner wall (73), and the winding drum (74a) of the outer peripheral side inner wall (73). It comprises a drive mechanism (74b, 74c) that translates while rotating in the width direction of the outlet opening (72c) formed at the other end,
The winding mechanism (74) is adapted to adjust the winding amount according to the ventilation resistance in the air flow path blown by the centrifugal multiblade fan (71),
By adjusting the winding amount, the outer peripheral side inner wall (73) is displaced, and the spread angle (n) of the substantially entire region of the part from the winding start portion to the winding end portion of the scroll casing (72) is changed. At the same time, the centrifugal blower characterized in that the opening area of the outlet opening (72c) is changed . The winding mechanism (74) increases the opening angle (n) at the same time as the draft resistance decreases, and simultaneously increases the opening area, and decreases the spread angle (n) as the draft resistance increases. The centrifugal blower according to claim 1, wherein the opening area is reduced at the same time. The drive mechanism (74b, 74c) includes a pinion (74b) provided on the take-up drum (74a) and a rack (74b) meshing with the pinion (74b). Item 3. The centrifugal blower according to Item 1 or 2.   The centrifugal blower according to any one of claims 1 to 3, wherein at least the outer peripheral side inner wall (73) is provided with a sound absorbing material that attenuates vibrations of air to reduce noise. A vehicular air conditioner having the centrifugal blower (7) according to any one of claims 1 to 4 and a blowing mode switching device (18 to 20) for switching a blowing mode of air blown into a room,
It has an electronic control unit (21) that determines the ventilation resistance based on the operating state of the blowing mode switching device (18 to 20) and controls the winding mechanism (74) according to the ventilation resistance. A vehicle air conditioner. A centrifugal blower (7) according to any one of claims 1 to 4,
A vehicle comprising: an electronic control unit (21) that determines the ventilation resistance based on an air flow rate of the centrifugal blower (7) and controls the winding mechanism (74) according to the ventilation resistance. Air conditioner. Air having the centrifugal blower (7) according to any one of claims 1 to 4, wherein at least one of an air blowing mode blown into the room and an air blowing amount of the centrifugal blower (7) is blown into the room. An automatic control type vehicle air conditioner that is controlled based on a target temperature (TAO) of the vehicle,
An air conditioner for vehicles , comprising: an electronic control unit (21) that determines the ventilation resistance based on the target temperature (TAO) and controls the winding mechanism (74) according to the ventilation resistance .

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