JP2001140795A - Centrifugal blower and air-conditioning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of a scroll shape without damaging the air supply function of a centrifugal blower through comparatively simple structure. SOLUTION: The spread angle of a scroll shape is reduced, the sectional shape of the flow passage of a spiral flow passage 22 forms a vertical length long in the axial direction of a centrifugal fan 1. A moving door 3 interlocking with a selected air-conditioning mode and rotating a direction Z such that the sectional area of the flow passage of the spiral flow passage 22 is regulated is situated at a lower plate 26 in the spiral flow passage 22. This constitution causes the moving door 3 to be equalized in a kind of conventional various air flow passages and be set and cope therewith through comparatively simple structure, prevents incurring of a rapid spreading loss of a flow of air, actuates the blower and the device with optimum fan efficiency at each air-conditioning mode by regulating the sectional area of a flow passage according to vent resistance changing according to each air-conditioning mode in an air- conditioning device, insures air supply performance, and reduces the size of a scroll shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal blower configured to increase or decrease the cross-sectional area of a flow passage in accordance with an air conditioning mode, and an air conditioner for a vehicle.

[0002]

2. Description of the Related Art A conventional centrifugal blower is disclosed in
As disclosed in Japanese Patent Application Laid-Open No. 3-93612, there is known an air conditioner that can be operated with almost optimum fan efficiency according to each air conditioning mode. That is, by switching the air conditioner for a vehicle, for example, in the blowing mode, the air flow path leading to the vehicle interior is switched, and the ventilation resistance in the air conditioner changes significantly. Further, the switching of the outlet temperature causes a case where the air passes through the heating heat exchanger and a case where the air bypasses, and similarly, the ventilation resistance in the air conditioner greatly changes. As a result, it is not possible to secure a sufficient amount of air in either the high resistance state or the low resistance state. Therefore, as shown in FIG. And a movable inner wall plate 36 for increasing or decreasing the flow path cross-sectional area of the spiral flow path 22, and interlocking with a blow mode switch lever 51 or a blow temperature switch lever 52, which constitutes an air conditioning mode switching means, to provide ventilation resistance. When the height is high, the movable inner wall plate 36 is moved in the rotation axis direction according to the low case, and the flow path cross-sectional area of the spiral flow path 22 is increased or decreased. Specifically, when the ventilation resistance is high, the flow path cross-sectional area is reduced, and when the ventilation resistance is low, the flow path cross-sectional area is increased. And the air volume can be increased.

For the same purpose as described above, Japanese Patent Publication No. 7-9
In Japanese Patent Publication No. 2079, as shown in FIG. 8, a divergence angle adjusting plate 37 is provided on the outer peripheral wall 27 of the scroll casing 2 as divergence angle increasing / decreasing means. It is known that the divergence angle adjusting plate 37 is rotated to change the divergence angle when the ventilation resistance is high or low. Specifically, if the ventilation resistance is high, the divergence angle is reduced, and if the ventilation resistance is low, the divergence angle is increased, enabling operation with optimal fan efficiency according to the ventilation resistance in each air conditioning mode. , The amount of air blow is improved.

[0004]

However, according to the invention disclosed in Japanese Patent Application Laid-Open No. 63-93612, the movable inner wall plate 36 for varying the cross-sectional area of the spiral flow path 22 is similar to the scroll shape of the scroll casing 2. It requires a large number of support portions (three in this example) and movable portions to move the centrifugal fan 1 in the direction of the rotation axis of the centrifugal fan 1, and the structure is complicated. In addition, since the movable inner wall plate 36 has a planar shape perpendicular to the rotation axis direction in the entire scroll casing 2, a shape in which the flow path cross-sectional area gradually increases in the rotation axis direction toward the discharge opening cannot be obtained. A sudden expansion at the air inflow portion of the air conditioning unit case is inevitable, and there is a problem that the air flow performance is reduced due to the expansion loss of the air flow and the noise is deteriorated.

[0005] The invention of Japanese Patent Publication No. 7-92079 has the following problems. That is, in recent years, with the need to expand the space in the vehicle interior, the demand for downsizing the centrifugal blower A has increased, and in particular, it has been necessary to downsize the scroll shape. When the scroll shape is reduced in size, the spread angle of the scroll shape is reduced, and the cross-sectional area of the flow passage in the scroll casing 2 is reduced. In this state, as shown in FIG.
7, when the divergence angle adjusting plate 37 is provided, when the ventilation resistance in the air conditioner is low, the divergence angle is already smaller than the optimum value due to miniaturization, and when the ventilation resistance is high, the divergence angle adjusting plate 37 Turns in the direction in which the divergence angle decreases, so the divergence angle further decreases,
When the resistance exceeds the optimum value and the resistance is low and high, the airflow cannot be secured with the optimum fan efficiency in both cases, and the scroll shape cannot be downsized.

SUMMARY OF THE INVENTION An object of the present invention is to provide a centrifugal blower which has a relatively simple structure and which can reduce the size of a scroll shape without impairing the conventional blower function.

[0007]

The present invention employs the following technical means to achieve the above object.

According to the first aspect of the present invention, the centrifugal fan (1) for discharging the sucked air in the radial direction and the suction portion (21) opening one end of the centrifugal fan (1) in the rotation axis direction. ), A spiral flow path (22) surrounding the centrifugal fan (1), and a discharge opening (24). The spiral flow path (22) faces the discharge opening (24). The scroll casing (2) whose flow path cross-sectional area gradually increases in the direction of the rotation axis of the centrifugal fan (1), and the centrifugal fan (1) is provided with a centrifugal centrifugal fan. An area increasing / decreasing means (3) which is displaced in the direction of the rotation axis of the fan (1) and increases / decreases the cross-sectional area of the spiral flow path (22) in accordance with the ventilation resistance on the downstream side of the scroll casing (2). ).

Thus, the scroll casing (2)
Thus, a shape in which the flow path gradually expands toward the discharge opening (24) can be secured, and performance degradation due to a sudden expansion loss of the air flow at the air inflow portion of the air conditioning unit case (C) can be prevented. Further, even when the divergence angle of the scroll shape is reduced, the cross-sectional area of the spiral flow path (22) can be secured in the rotation axis direction of the centrifugal fan (1), and the scroll casing (2) For air flowing densely on the side opposite to the suction section (21), the air flow is changed to a flow path cross-sectional area corresponding to the velocity distribution of air that changes due to ventilation resistance in each air-conditioning mode, and optimum fan efficiency is obtained. A sufficient amount of air can be secured, and the scroll shape can be reduced in size.

According to the second aspect of the present invention, the area increasing / decreasing means (3) has one end rotatably fixed to the upstream side of the air and the other end rotatable to the downstream side of the air. ).

[0011] Thus, the movable door (3) is of the same kind as the various air flow path switching doors used in the conventional air conditioner, and can be set with a relatively simple structure. Can secure a shape in which the flow path cross-sectional area gradually increases in the direction of the rotation axis toward the discharge opening (24), and the performance due to the rapid expansion loss of the air flow at the air inlet of the air conditioning unit case (C) Drop can be prevented. Also, even if the spread angle of the scroll shape is reduced,
By changing the flow path cross-sectional area of the spiral flow path (22) by the movable door (3), an optimum fan efficiency is obtained in each air-conditioning mode having a different ventilation resistance, and a sufficient air flow rate is secured. The size of the scroll can be reduced.

According to the third aspect of the present invention, the movable door (3) is provided with a second movable door (32) that further pivots at a downstream end portion of the air.

According to this, in addition to the above effects, when the movable door (3) is operated in a direction to reduce the cross-sectional area of the spiral flow path (22), the second movable door (3) is actuated. 32) closes a gap (35) formed between the suction portion (21) of the scroll casing (2) and the surface of the scroll casing (2) facing the suction portion, prevents backflow of the air flow, and more effectively achieves optimum fan efficiency. Can be obtained.

According to the fourth aspect of the present invention, a centrifugal fan (1) for discharging sucked air in a radial direction, a scroll casing (2) in which the centrifugal fan (1) is housed, and A plurality of outlets (1) arranged downstream of the scroll casing (2) and blowing air-conditioned air downstream.
5, 16 and 17), and a plurality of doors (11, 11) arranged in this air passage to open and close the outlets (15, 16, 17) respectively and switch the air conditioning mode.
12, 13, 14), wherein
The scroll casing (2) has a suction portion (2) formed at one end of the centrifugal fan (1) in the direction of the rotation axis.
1), the cross-sectional area of the flow path gradually increases in the direction of the rotation axis of the centrifugal fan (1) as it is formed in a spiral shape, and the air discharged from the centrifugal fan (1) passes through. The scroll casing (2) is displaced in the rotation axis direction of the centrifugal fan (1) on the side of the scroll casing (2) facing the suction portion (21), and the air conditioning is performed. According to the mode, the spiral channel (2)
It is characterized in that an area increasing / decreasing means for increasing / decreasing the flow path cross-sectional area of 2) is provided.

[0015] According to this, according to the ventilation resistance of the air flow path which is changed by switching the air conditioning mode of the air conditioner,
Sufficient airflow can be secured with optimal fan efficiency.

Incidentally, the reference numerals in parentheses of the above-mentioned means indicate the correspondence with the concrete means described in the embodiment described later.

[0017]

(First Embodiment) A first embodiment of the present invention is shown in FIGS. 1 to 3, and a specific configuration thereof will be described below. FIG. 1 shows an overall configuration of an air conditioner for a vehicle to which the present invention is applied.
This air conditioner is arranged below the front instrument panel in the vehicle interior. Inside / outside air switching doors 81 and 82 provided in the inside / outside air switching box B are interlocked by air conditioning mode switching means (not shown) in the vehicle interior to selectively introduce the inside air or outside air to the centrifugal blower A. The centrifugal fan 1 of the centrifugal blower A is driven by the motor 7, and the introduced air flows in the scroll casing 2 and is sent from the discharge unit 23 to the air conditioning unit case C. The air introduced into the air-conditioning unit case C passes through the cooling heat exchanger 9 and is cooled by heat exchange. Further, the air-mixing door 11 is opened and closed in conjunction with the air-conditioning mode switching means (not shown) in the passenger compartment. , The air flow path X that passes through the heating heat exchanger 10 and is heated by the heat exchange, and the heating heat exchanger 1
The air flow path Y bypassing the air flow path 0 is selected, and air conditioning is performed according to the ratio of air passing through both air flow paths. Then, each door 12, 1 provided in the air flow path on the downstream side thereof
The air outlets 3 and 14 are linked to each other by an air conditioning mode switching means (not shown) and are opened and closed to open and close the selected vehicle interior, that is, the face outlet 15, the defroster outlet 16, and the foot outlet 17. Air-conditioning wind blows out.

FIG. 2 shows details of the centrifugal blower A, and FIG. 3 shows a longitudinal section thereof. The centrifugal blower A includes a centrifugal fan 1 for discharging air introduced from the inside / outside air switching box B in a radial direction, a motor 7 for driving the centrifugal fan 1 (not shown in this drawing), and a scroll. It is composed of a casing 2. The scroll casing 2
An upper plate 25 forming a suction portion 21 opening one end of the centrifugal fan 1 in the direction of the rotation axis, and a lower plate 2 facing the upper plate 25.
6, and an outer peripheral wall 27 connecting the outer peripheral end of the upper plate 25 and the outer peripheral end of the lower plate 26. A spiral flow path 22 is formed so as to surround the centrifugal fan 1, and A discharge opening 24 is provided in the downstream part. The upper plate 25 and the lower plate 26
, That is, the dimension H in the rotation axis direction of the centrifugal fan 1
But gradually expands toward the discharge opening 24,
The lower plate 26 is inclined downward. Thus, the cross-sectional area of the spiral flow path 22 is also discharged and gradually expanded toward the opening 24.

In recent years, due to the need to expand the cabin space,
There is an increasing demand for downsizing the scroll casing 2. In order to reduce the scroll shape, the divergence angle that determines the scroll shape is reduced. As shown in FIG. 4, the divergence angle is a point where a virtual extension line (a) is drawn upstream of the inner surface of the outer peripheral wall 27 of the scroll casing 2 and intersects with the outer peripheral surface 1a of the centrifugal fan 1 (b). Using the point (b) as a reference point, the intersection of the extension line of the radius of the centrifugal fan 1 at the position of the rightward rotation angle θ of the centrifugal fan 1 and the outer peripheral wall 27 of the scroll casing 2 is (c), and Similarly, assuming that the point of intersection with the outer peripheral surface 1a of the centrifugal fan 1 is (d), at the rotation angle θ, the intersection of the tangents to the curved surfaces respectively drawn at the points (c) and (d) (in this case, the angle α). If the divergence angle α is reduced to β, the scroll shape becomes slightly smaller inward as shown by the solid line (e), resulting in a smaller size. Accordingly, the radial dimension W of the discharge opening 24 is reduced from W1 to W2.

As described above, in the present embodiment, the cross-sectional shape of the spiral flow path 22 of the scroll casing 2 is
6, the centrifugal fan 1 has a vertically elongated shape in which the dimension H in the rotation axis direction is larger than the dimension W in the radial direction. The movable door 3 for increasing or decreasing the flow path cross-sectional area is provided. The movable door 3 has a flat plate shape, one end of which is rotatably fixed to a rotation shaft 4 at a substantially end point of a winding angle of the scroll casing 2, and a door lever 5 fixed to the rotation shaft 4.
Is connected to a blowing mode switching lever, which is, for example, an air-conditioning mode switching means in a vehicle compartment (not shown) by a wire 6, and in cooperation with the blowing mode switching lever, the other end on the downstream side rotates in the Z direction of the rotation axis. It works.

Next, the operation of the present invention will be described. As the radial dimension W of the spiral flow path 22 becomes smaller due to the downsizing of the scroll shape, the lower plate 26 is discharged and the opening 2
4 to increase the rotation axis direction dimension H and increase the flow path cross-sectional area in the longitudinal direction, so that the flow path cross-sectional area in the case of the conventional structure before miniaturizing the scroll shape is reduced. By making them equal, it is possible to secure an air flow rate. However, for example, when the ventilation resistance in the air conditioner that passes through the heating heat exchanger 10 increases, the amount of air blows down and the flow velocity of the air drops, so that the cross-sectional area of the spiral flow path 22 is reduced. If they are the same, they will operate at a point where the fan efficiency is poor.

As shown in FIG. 3, the flow velocity distribution of the air discharged from the centrifugal fan 1 generally increases toward the lower part of the centrifugal fan 1 in an obliquely downward direction having a discharge angle θF. In this example, the distribution is such that the lower plate 26 side of the scroll casing 2 is dense. Focusing on the flow velocity distribution of the air, when the ventilation resistance in the air conditioner increases, the flow velocity distribution 27a changes to 27b, and the lower the flow velocity, the lower the movable door 3 on the lower plate 26 side. By rotating, changing the inclination of the lower plate 26 and reducing the cross-sectional area of the spiral flow path 22, the operation can be performed at an efficient point.

When the spread angle of the scroll shape is reduced from 6.5 degrees to 5.5 degrees and the ventilation resistance of the air conditioner is low, that is, the air bypasses the heating heat exchanger 10 and the blowing mode is the face. In the case of the outlet 15, the movable door 3
Was rotated downward, and the original dimension H in the rotation axis direction of the discharge opening 24 was set to 136 mm in accordance with the lower plate 26. On the other hand, when the ventilation resistance is high, that is, when the air passes through the heating heat exchanger 10 and the blowing mode is the defroster outlet 16
In the case of the foot outlet 17, the movable door 3 was turned upward, and the dimension H in the rotation axis direction was set to 86 mm. In both cases, the total pressure of the centrifugal blower A (P1
P2), fan efficiency (η1 and η2), and ventilation resistance (K1 and K2) of the air conditioner, the graph shown in FIG. 5 was obtained. In this graph, the subscript 1 of the characteristic graph symbol of the total pressure and the fan efficiency indicates the discharge opening 24.
When the rotation axis direction dimension H is 136 mm, the subscript 2
Indicates a case where the dimension H in the rotation axis direction is 86 mm. The suffix 1 of the characteristic graph symbol of the ventilation resistance indicates a low resistance, and the suffix 2 indicates a high resistance. As is apparent from this graph, when the resistance H is 136 mm, the operating point when the discharge opening 24 in the rotation axis direction is 136 mm at the time of low resistance is almost the maximum fan efficiency c. Discharge opening 2
If the flow path cross-sectional area of No. 4 remains the same, the operating point is b and the fan efficiency is d, which is lower than c, and it can be seen that the fan cannot be operated at the optimum fan efficiency. However, the movable door 3 is turned upward, and the dimension H in the rotation axis direction of the discharge opening 24 is set to 8
If it is reduced to 6 mm, the gradient of the total pressure characteristics of the blower will increase, the pressure on the low air volume side will increase, the maximum efficiency point of the fan will also move to the low air volume side, the operating point will be e, and the fan efficiency will be further increased. Is almost the optimal f.

As described above, the movable door 3 is of the same kind as the various air flow path switching doors used in the conventional air conditioner, can be set with a relatively simple structure, and the scroll casing 2 discharges. A shape in which the cross-sectional area of the flow passage gradually increases toward the opening 24 can be ensured, and performance degradation due to a sudden expansion loss of the air flow at the air inflow portion of the air conditioning unit case C can be prevented. Even if the divergence angle of the scroll shape is reduced, the flow path cross-sectional area can be secured by increasing the size H in the rotation axis direction of the spiral flow path 22, and air flowing densely to the lower plate 26 side of the scroll casing 2. On the other hand, the airflow resistance of each air-conditioning mode changes the cross-sectional area of the flow path to match the velocity distribution of the air, moves the maximum efficiency point of the fan, and operates the centrifugal blower A with almost optimal fan efficiency. In this case, a sufficient amount of air can be supplied, and the scroll shape can be reduced in size.

(Second Embodiment) Next, a second embodiment of the present invention is shown in FIG. A second movable door 32 is provided on the downstream side of the first movable door 31 on the upstream side of the movable door 3,
The downstream end of the movable door 31 and the upstream end of the second movable door 32 are rotatably connected by a door shaft 33.

Thus, in addition to the effects of the first embodiment, when the door lever 5 is operated in conjunction with the air-conditioning mode switching means (not shown) to rotate the first movable door 31 upward, The distal end portion 34 of the movable door 32 is in contact with the lower plate 26 by its own weight, closes the gap 35 formed between the first movable door 31 and the lower plate 26, and prevents the flow of air from flowing back to the gap 35. More effectively, optimal fan efficiency can be obtained.

The position of the rotary shaft 4 of the movable door 3 does not always need to coincide with the end point of the winding angle of the scroll casing 2 as described above. Even if there is some deviation, the same effect can be obtained. Can be

As means for interlocking the air-conditioning mode switching means and the movable door 3, a servo controlled by an electric signal transmitted in accordance with the operation of the air-conditioning mode switching means instead of the wire 6 shown in the figure. Motors and various actuators can also be used.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an entire air conditioner for a vehicle, showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing a centrifugal blower according to the first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of FIG. 2;

FIG. 4 is a plan view showing a spread angle of a scroll shape.

FIG. 5 shows the total pressure, efficiency, and the amount of air blown by a centrifugal blower.
It is a graph which shows the relationship of ventilation resistance.

FIG. 6 is a perspective view showing a centrifugal blower according to a second embodiment of the present invention.

FIG. 7 is an overall configuration diagram schematically showing Conventional Technique 1.

FIG. 8 is an overall configuration diagram schematically showing Conventional Technique 2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Centrifugal fan 2 Scroll casing 21 Suction part 22 Spiral flow path 23 Discharge part 24 Discharge opening part 25 Upper plate 26 Lower plate 27 Outer peripheral wall 3 Movable door (area increase / decrease means) 4 Rotating shaft 5 Door lever 6 Wire

Claims (4)

[Claims] 1. A centrifugal fan (1) for discharging sucked air in a radially outward direction, a suction part (21) opening one end of the centrifugal fan (1) in a rotation axis direction, and the centrifugal fan (1). 1), a spiral channel (22) surrounding the spiral channel (2), and a discharge opening (24).
2) a scroll casing (2) in which the cross-sectional area of the flow passage gradually increases in the direction of the rotation axis of the centrifugal fan (1); and the suction portion (2) of the scroll casing (2).
The spiral flow path (2) is displaced in the direction of the rotation axis of the centrifugal fan (1) on the side facing 1) according to the ventilation resistance on the downstream side of the scroll casing (2).
A centrifugal blower comprising: (2) an area increasing / decreasing means (3) for increasing / decreasing a flow path cross-sectional area. 2. The area increasing / decreasing means (3) is a movable door (3) having one end rotatably fixed to the upstream side of the air and the other end pivoting to the downstream side of the air. The centrifugal blower according to claim 1. 3. The centrifugal blower according to claim 2, wherein the movable door (3) has a second movable door (32) that further pivots at the downstream end of the air. 4. A centrifugal fan (1) for discharging sucked air in a radial direction, a scroll casing (2) in which the centrifugal fan (1) is housed, and a downstream of the scroll casing (2). And a plurality of outlets (15, 16, 1) that blow air-conditioning air downstream.
7) is formed in the air flow path, and the air outlets (15, 16, 1) are arranged in the air flow path.
7) In an air conditioner having a plurality of doors (11, 12, 13, 14) for opening and closing the respective air conditioning modes, the scroll casing (2) is provided in the direction of the rotation axis of the centrifugal fan (1). The suction part (2
1), the cross-sectional area of the flow path gradually increases in the direction of the rotation axis of the centrifugal fan (1) as it is formed in a spiral shape, and the air discharged from the centrifugal fan (1) passes through. The scroll casing (2) is displaced in the rotation axis direction of the centrifugal fan (1) on the side of the scroll casing (2) facing the suction portion (21), and the air conditioning is performed. According to the mode, the spiral channel (2)
2) An air conditioner comprising an area increasing / decreasing means for increasing / decreasing a flow path cross-sectional area.