Filters and centrifugal blowers

Abstract

[Problem] To improve the strength and producibility of a filter having a filtration material in a pleated shape. [Solution] This filter (40) comprises a filtration material (41) having a partitioned surface (43) that is partitioned by mountain-fold pleats (42) and valley-fold pleats (42), and end plates (48, 49) that are fixed to the two end sections of the filtration material (41) and that maintain the filtration material (41) in a pleated shape. The filtration material (41) includes a plurality of filtration sections (45a, 45b, 45c), and intermediate sections (46a, 46b) provided between adjacent filtration sections. In the filtration sections, the angle formed by adjacent partitioned surfaces (43, 43) is greater than 0°. In the intermediate sections (46a, 46b), the angle formed by adjacent partitioned surfaces (43, 43) is 0°.

Description

[Technical Field]

[0001] The present invention relates to a filter and a centrifugal blower equipped with the filter. [Background technology]

[0002] Generally, a filter is incorporated into a blower used in a vehicle air conditioner to remove dust and other particles from the air taken in by the blower. The filter includes a pleated filter material and a frame that supports the filter material. Patent Document 1 discloses such a filter.

[0003] In recent years, however, there has been a demand for improving the strength and productivity of such filters. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-132637 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to improve the productivity of filters while also improving the strength of the filters. Another object of the present invention is to provide a centrifugal blower that uses such a filter and reduces the risk of unintentional mixing of two types of air with different properties. [Means for solving the problem]

[0006] According to a preferred embodiment of the present invention, A filter medium having alternating mountain folds and valley folds, and having partition surfaces defined by the mountain folds and the valley folds; end plates fixed to both ends of the filter medium in the direction in which the mountain folds and the valley folds extend to maintain the filter medium in a pleated shape; Equipped with The filter medium includes a plurality of filtering sections arranged along the direction in which the mountain folds and the valley folds are arranged, each including a plurality of partition surfaces, and an intermediate section provided between adjacent filtering sections; In the filtration section, the angle formed by the adjacent partition surfaces is greater than 0°, In the intermediate portion, a filter is provided in which the angle between adjacent partition surfaces is 0°.

[0007] Alternatively, according to a preferred embodiment of the present invention: A centrifugal blower for a vehicle, A motor; a first impeller having a plurality of blades forming a first circumferential blade row, the first impeller being rotationally driven by the motor about a rotation axis extending in the axial direction, and blowing air in a space radially inside the first blade row radially outward; a blower case including: a second impeller having a plurality of blades forming a second circumferential blade row, which is rotationally driven about the rotation axis by the motor and which blows air in a space radially inside the second blade row radially outward; a first scroll which houses the first impeller, which has a first suction port which opens in the axial direction and a first discharge port which opens in the circumferential direction, and which discharges air drawn in from the first suction port through the first discharge port as the first impeller rotates; and a second scroll which houses the second impeller, which has a second suction port which opens in the axial direction and a second discharge port which opens in the circumferential direction, and which discharges air drawn in from the second suction port through the second discharge port as the second impeller rotates; an air intake housing connected to the blower case and accommodating the filter therein, the air intake housing having an outside air inlet for taking in outside air of the vehicle, an inside air inlet for taking in inside air of the vehicle, an upstream air introduction space which serves as an air passage between the outside air introduction port and the inside air introduction port and the filter, and a downstream air introduction space which accommodates the filter and serves as an air passage between the upstream air introduction space and the blower case; Equipped with a partition wall is provided in the upstream air introduction space to separate the air introduced from the outside air introduction port and the air introduced from the inside air introduction port, the filter is disposed in the downstream air introduction space such that an imaginary plane defined by the extending direction of the mountain folds and the valley folds and the arranging direction of the mountain folds and the valley folds crosses the air flowing through the downstream air introduction space, The centrifugal blower is provided, wherein the end of the partition wall facing the filter and the middle part of the filter are aligned along the flow direction of air flowing through the downstream air introduction space. [Effects of the Invention]

[0008] According to the above-described embodiment of the present invention, it is possible to improve the productivity of the filter and the strength of the filter. Also, according to the embodiment of the present invention, it is possible to provide a centrifugal fan in which the risk of unintentional mixing of two types of air with different properties is reduced. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a centrifugal fan according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a longitudinal sectional view including a meridian section of the centrifugal blower shown in FIG. [Figure 3] 3 is a longitudinal cross-sectional view including a meridian section of the centrifugal blower taken along a cutting plane perpendicular to the cutting plane in FIG. 2. FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 6 is a cross-sectional view of the filter shown in FIG. 5 cut along the direction in which the folds are aligned. [Figure 7] 6A to 6C are diagrams illustrating a method for manufacturing the filter shown in FIG. 5. [Figure 8] 6A to 6C are diagrams illustrating a method for manufacturing the filter shown in FIG. 5. [Figure 9] FIG. 7 is a diagram corresponding to FIG. 6 and showing a modified example of the filter. [Figure 10] FIG. 7 is a diagram corresponding to FIG. 6 and showing another modified example of the filter. [Figure 11] FIG. 4 is a view corresponding to FIG. 3 and is a vertical cross-sectional view of a centrifugal fan according to a second embodiment. [Figure 12] FIG. 7 is a diagram corresponding to FIG. 6 and showing a filter according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment A first embodiment of the present invention will be described below with reference to the accompanying drawings.

[0011] Fig. 1 is a perspective view of a centrifugal fan according to a first embodiment of the present invention. Fig. 2 and Fig. 3 are diagrams schematically showing a cross section of the centrifugal fan shown in Fig. 1. However, Fig. 3 is a diagram showing a cross section perpendicular to the cross section in Fig. 2. In Fig. 2 and Fig. 3 and other figures, arrows extending in a direction perpendicular to the paper surface are represented by symbols each consisting of a dot within a circle.

[0012] The centrifugal blower 1 shown in Figures 1 to 3 is a centrifugal blower incorporated into a vehicle air conditioning system, and has a motor 2, a first impeller 3 and a second impeller 4 that are rotationally driven by the motor 2, a blower case 10 that houses the first impeller 3 and the second impeller 4, and an air intake housing 20.

[0013] For ease of explanation, the direction of the rotational axis Ax of the motor 2 and the impellers 3 and 4 will be referred to herein as the "axial direction" or the "vertical direction," and the upper and lower sides of FIGS. 2 and 3 will be referred to as the "one axial side," the "upper axial side," the "other axial side," or the "lower axial side," respectively. However, this does not mean that the direction of the rotational axis Ax is limited to the vertical direction when the centrifugal blower is actually installed in a vehicle. Furthermore, in this specification, unless otherwise noted, the direction of the radius of a circle drawn on a plane centered on an arbitrary point on the rotational axis Ax and perpendicular to the rotational axis Ax will be referred to as the radial direction, and the circumferential direction of the circle will be referred to as the circumferential direction or the circumferential direction.

[0014] The first impeller 3 has a plurality of blades 3a arranged in the circumferential direction on its outer periphery to form a first blade row. The first impeller 3 is connected to the rotary shaft 2a of the motor 2 and is driven to rotate about the rotation axis Ax, and blows air radially inside the first blade row of the first impeller 3 outward in the radial direction.

[0015] The second impeller 4 also has a plurality of blades 4a arranged in the circumferential direction on its outer periphery, forming a second blade row. The second impeller 4 is disposed below (on the other axial side of) the first impeller 3, and is connected to the rotary shaft 2a of the motor 2. The second impeller 4 is driven to rotate about the rotation axis Ax, and blows air radially inward of the second blade row of the second impeller 4 radially outward.

[0016] The blower case 10 has a first scroll 11 that houses the first impeller 3 and a second scroll 12 that houses the second impeller 4.

[0017] The first scroll 11 has a first suction port 11a that opens in the axial direction and a first discharge port 11b that opens in the circumferential direction. When the first scroll 11 is viewed from the axial direction, the first discharge port 11b extends in a direction generally tangential to the outer circumferential surface of the first scroll 11. As the first impeller 3 rotates, the first scroll 11 discharges air drawn in through the first suction port 11a from the first discharge port 11b. In the illustrated example, the first suction port 11a opens to the upper side in the axial direction (one side in the axial direction). Furthermore, the first discharge port 11b can discharge air to a defroster outlet and / or a vent outlet of the vehicle.

[0018] The second scroll 12 has a second intake port 12a that opens in the axial direction and a second discharge port 12b that opens in the circumferential direction. When the second scroll 12 is viewed from the axial direction, the second discharge port 12b extends in a direction generally tangential to the outer circumferential surface of the second scroll 12. As the second impeller 4 rotates, the second scroll 12 discharges air drawn in through the second intake port 12a from the second discharge port 12b. In the illustrated example, the second intake port 12a opens to the upper side in the axial direction (one side in the axial direction). In addition, the second discharge port 12b can discharge air to a foot outlet of the vehicle.

[0019] 1 to 3, the first scroll 11 and the second scroll 12 are formed by dividing the internal space of an integrally molded scroll housing 10a by a partition wall 15. More specifically, the partition wall 15 extends radially inward from the outer peripheral wall of the scroll housing 10a and divides the region of the internal space of the scroll housing 10a between the inner peripheral surface of the scroll housing 10a and the outer peripheral surfaces of the impellers 3, 4 in the axial direction (up and down). The first scroll 11 and the second scroll 12 are formed on both sides of the partition wall 15.

[0020] In the example shown in Figures 1 to 3, the centrifugal blower 1 is a single-suction type centrifugal blower, and the internal space of the first scroll 11 and the internal space of the second scroll 12 are connected via a second suction port 12a.

[0021] In the illustrated example, the first impeller 3 and the second impeller 4 are integrally formed. More specifically, the first blade row of the first impeller 3 and the second blade row of the second impeller 4 are connected in the axial direction via an annular dividing wall 5. The dividing wall 5 divides the spaces between the plurality of first blades 3a and the spaces between the plurality of second blades 4a. The position of the dividing wall 5 in the axial direction generally coincides with the position of the partition wall 15 of the scroll housing 10a in the axial direction.

[0022] An inner deflection member 6 is integrally formed with the impellers 3 and 4. The inner deflection member 6 is sometimes called a cone portion. This inner deflection member 6 is a rotating body in a geometric sense. In the illustrated example, it has a peripheral side portion 6a connected to the lower end of the second impeller 4 and a disk-shaped central portion 6b. The central portion 6b is connected to the rotary shaft 2a of the motor 2. Note that the central portion 6b does not necessarily have to be disk-shaped, and may have a well-known boss shape.

[0023] 2 and 3, a separation tube 30 is inserted into the scroll housing 10a via the first suction port 11a. The separation tube 30 divides the flow of air drawn into the scroll housing 10a from the first suction port 11a into a first air flow that passes outside the separation tube 30 and a second air flow that passes inside the separation tube 30.

[0024] FIG. 4 shows a perspective view of the separation tube 30. As shown in FIG. 4, the separation tube 30 has an inlet end (upper portion) 31, a body portion (central portion) 32 connected to the inlet end 31 from the other axial side, and an outlet end (lower portion) 33 connected to the body portion 32 from the other axial side. A cross section of the inlet end 31 perpendicular to the axial direction is generally rectangular. The upper end of the inlet end 31 has a first edge portion 31a and a second edge portion 31b extending parallel to each other, a third edge portion 31c connecting one end of the first edge portion 31a and the second edge portion 31b, and a fourth edge portion 31d connecting the other end of the first edge portion 31a and the second edge portion 31b. The cross-sectional shape of the separation tube 30 smoothly transitions from rectangular to circular (or generally circular) as it approaches the body portion 32 from the inlet end 31. The outlet end 33 of the separation tube 30 has a flared shape that increases in diameter as it approaches the bottom end.

[0025] The entire separation barrel 30 may be integrally molded by resin injection molding. Alternatively, the inlet end 31 of the separation barrel 30 and the body 32 and outlet end 33 of the separation barrel 30 may be molded separately and then connected together.

[0026] 2 and 3, the inlet end portion 31 is located outside the scroll housing 10a (on one side (above) in the axial direction of the first suction port 11a of the first scroll 11). The body portion 32 extends in the axial direction, passing radially inside the first suction port 11a and the radially inside of the first blade row of the first impeller 3. The outlet end portion 33 is provided so that its lower end is located at approximately the same position as the partition wall 15 of the scroll housing 10a in the axial direction.

[0027] As described above, the separation cylinder 30 divides the flow of air drawn into the scroll housing 10a into a first air flow passing through the first passage 30A outside the separation cylinder 30 and a second air flow passing through the second passage 30B inside the separation cylinder 30. The first air flow passes through a ring-shaped region of the first suction port 11a of the first scroll 11 that is outside the outer circumferential surface of the separation cylinder 30 and flows radially inward of the first blade row of the first impeller 3. The second air flow enters the separation cylinder 30 from the upper end thereof and flows through the second suction port 12a of the second scroll 12 and flows radially inward of the second blade row of the second impeller 4. The outlet-side end 33 of the separation cylinder 14 turns the incoming first air flow radially outward and guides it to the first scroll 11, and turns the incoming second air flow radially outward and guides it to the second scroll 12.

[0028] An air intake housing 20 is disposed on one axial side of the fan case 10 so as to cover the first air inlet 11a. The fan case 10 and the air intake housing 20 may be integrally molded, or may be manufactured separately and then connected by means of screwing, bonding, fitting, or the like. In a preferred embodiment, the separation cylinder 30 is a component separate from the fan case 10 and the air intake housing 20, and is supported in a predetermined position by the air intake housing 20.

[0029] The internal space of the air intake housing 20 is in communication with the first air inlet 11a of the scroll housing 10a. In other words, the first air inlet 11a opens toward the internal space of the air intake housing 20. As shown in FIG. 1, the air intake housing 20 has first to third outside air inlets 21, 22, and 23 that open generally forward, and first to third inside air inlets 24, 25, and 26 that open generally rearward. The first to third outside air inlets 21, 22, and 23 are connected to outlets (not shown) of outside air inlet passages provided in the vehicle, and take in outside air from the vehicle. The first to third inside air inlets 24, 25, and 26 open into the vehicle cabin, allowing inside air from the vehicle to be introduced into the air intake housing 20. The internal space of air intake housing 20 forms air passages between first to third outside air inlet ports 21, 22, 23 and first to third inside air inlet ports 24, 25, 26 and blower case 10. Hereinafter, the internal space of air intake housing 20 will also be referred to as the "air introduction space."

[0030] The air intake space of the air intake housing 20 includes an upstream air intake space 20A that communicates with the outside air intake ports 21, 22, and 23 and the inside air intake ports 24, 25, and 26, and a downstream air intake space 20B that connects to the other side of the upstream air intake space 20A in the axial direction. A filter 40, which will be described later, is disposed in the downstream air intake space 20B. The upstream air intake space 20A is partitioned by a first partition wall 27a and a second partition wall 27b that extend in the up-down direction and the front-rear direction. The first partition wall 27a and the second partition wall 27b are aligned in the left-right direction. The upstream air introduction space 20A is separated by a first partition 27a and a second partition 27b into a first upstream air introduction space 20A1 that communicates with the first outside air introduction port 21, the first inside air introduction port 24, and the downstream air introduction space 20B, a second upstream air introduction space 20A2 that communicates with the second outside air introduction port 22, the second inside air introduction port 25, and the downstream air introduction space 20B, and a third upstream air introduction space 20A3 that communicates with the third outside air introduction port 23, the third inside air introduction port 26, and the downstream air introduction space 20B.

[0031] A first switching door 28a, a second switching door 28b, and a third switching door 28c are provided in the first to third upstream air introduction spaces 20A1, 20A2, and 20A3, respectively. In the illustrated example, each of the switching doors 28a, 28b, and 28c is a type known as a rotary door, and can be rotated about a pivot axis Bx extending in the left-right direction by an actuator (not shown). Each of the switching doors 28a, 28b, and 28c has an arc wall 29 having an arc-shaped cross section centered on the pivot axis Bx.

[0032] The first switching door 28a provided in the first upstream air introduction space 20A1 is movable between a first position where the first outside air introduction port 21 is opened and the first inside air introduction port 24 is closed, and a second position where the first outside air introduction port 21 is closed and the first inside air introduction port 24 is opened. By placing the first switching door 28a in the first position, it is possible to allow outside air to flow into the air intake housing 20 from the first outside air introduction port 21 and to block inside air from flowing into the air intake housing 20 from the first inside air introduction port 24. Furthermore, by placing the first switching door 28a in the second position, it is possible to block outside air from flowing into the air intake housing 20 from the first outside air introduction port 21 and to allow inside air to flow into the air intake housing 20 from the first inside air introduction port 24. In FIG. 1 , the first switching door 28a is placed in the first position.

[0033] Further, the second switching door 28b provided in the second upstream air introduction space 20A2 is movable between a first position where the second outside air introduction port 22 is opened and the second inside air introduction port 25 is closed, and a second position where the second outside air introduction port 22 is closed and the second inside air introduction port 25 is opened. By placing the second switching door 28b in the first position, it is possible to allow outside air to flow into the air intake housing 20 from the second outside air introduction port 22 and to block inside air from flowing into the air intake housing 20 from the second inside air introduction port 25. By placing the second switching door 28b in the second position, it is possible to block outside air from flowing into the air intake housing 20 from the second outside air introduction port 22 and to allow inside air to flow into the air intake housing 20 from the second inside air introduction port 25. In FIG. 1, the second switching door 28b is placed in the second position.

[0034] Furthermore, the third switching door 28c provided in the third upstream air introduction space 20A3 is movable between a first position where the third outside air introduction port 23 is opened and the third inside air introduction port 26 is closed, and a second position where the third outside air introduction port 23 is closed and the third inside air introduction port 26 is opened. By placing the third switching door 28c in the first position, it is possible to allow outside air to flow into the air intake housing 20 from the third outside air introduction port 23 and to block inside air from flowing into the air intake housing 20 from the third inside air introduction port 26. By placing the third switching door 28c in the second position, it is possible to block outside air from flowing into the air intake housing 20 from the third outside air introduction port 23 and to allow inside air to flow into the air intake housing 20 from the third inside air introduction port 26. In FIG. 1, the third switching door 28c is placed in the first position.

[0035] The partition walls 27a, 27b of the air intake housing 20 and the separation cylinder 30 are arranged relative to each other as follows: That is, the partition walls 27a, 27b and the separation cylinder 30 are arranged relative to each other so that almost all of the air introduced into the air intake housing 21 from the first outside air inlet 21 or the first inside air inlet 24 and the air introduced into the air intake housing 20 from the third outside air inlet 23 or the third inside air inlet 26 passes through the first passage 30A outside the separation cylinder 30. Also, the partition walls 27a, 27b and the separation cylinder 30 are arranged relative to each other so that almost all of the air introduced into the air intake housing 20 from the second outside air inlet 22 or the second inside air inlet 25 passes through the second passage 30B inside the separation cylinder 30. More specifically, a lower end portion (end portion 27aa facing filter 40, which will be described later) of first partition wall 27a and a first edge portion 31a of inlet end portion 31 are aligned in the flow direction (generally the axial direction) of air flowing through downstream air introduction space 20B of air intake housing 20. Furthermore, a lower end portion (end portion 27ba facing filter 40, which will be described later) of second partition wall 27b and a second edge portion 31b of inlet end portion 31 are aligned in the flow direction of air flowing through downstream air introduction space 20B.

[0036] Next, the filter 40 will be described with reference to Figures 2, 3, and 5 to 8. As described above, the filter 40 is disposed in the downstream air introduction space 20B of the air intake housing 20 so as to cross the air flowing through the downstream air introduction space 20B. The filter 40 is provided to remove pollutants such as dust and particles, as well as unpleasant odors, from the air that has flowed into the air intake housing 20. The filter 40 is inserted into slots or rails (not shown) provided in the air intake housing 20 and is held between the first and second partition walls 27a and 27b and the inlet end 31 of the separation cylinder 30.

[0037] The filter 40 includes a filter medium 41 that captures contaminants in the air that flows into the air intake housing 20, and a pair of end plates 48, 49 that hold the filter medium 41. The filter medium 41 is made of, for example, nonwoven fabric. The filter medium 41 is made of, for example, resin fibers such as polypropylene, polyester, or nylon. The end plates 48, 49 are made of, for example, polyester or polypropylene.

[0038] The filter medium 41 has a pleated shape. More specifically, mountain folds 42 and valley folds 42 are formed alternately in the filter medium 41. The filter medium 41 has a plurality of partitions 43 defined by the mountain folds 42 and valley folds 42. Hereinafter, the direction D1 in which the mountain folds 42 and valley folds 42 extend will also be referred to as the "first direction D1." Furthermore, the direction D2 in which the mountain folds 42 and valley folds 42 are aligned will also be referred to as the "second direction D2." The filter 40 is disposed such that an imaginary plane P extending in the first direction D1 and the second direction D2 crosses the air flowing through the downstream air introduction space 20B.

[0039] The end plates 48, 49 are fixed to both ends of the filter medium 41 in the first direction D1 to maintain the pleated shape of the filter medium 41. Each of the end plates 48, 49 is made of a single element with no joints in the second direction D2. This improves the productivity of the filter 40 and the strength of the filter 40 compared to when each end plate 48, 49 is made of multiple elements with joints in the second direction D2.

[0040] The filter medium 41 includes a plurality of filtration sections 45a, 45b, and 45c arranged along the second direction D2. The filter medium 41 also includes intermediate sections 46a and 46b provided between adjacent filtration sections. In the illustrated example, the filter medium 41 includes first, second, and third filtration sections 45a, 45b, and 45c, as well as first and second intermediate sections 46a and 46b. The first intermediate section 46a is disposed between the first and second filtration sections 45a and 45b. The second intermediate section 46b is disposed between the second and third filtration sections 45b and 45c.

[0041] Each of the filtration sections 45a, 45b, and 45c and each of the intermediate sections 46a and 46b includes a plurality of partition surfaces 43. In the illustrated example, the first and third filtration sections 45a and 45c each include six partition surfaces 43. The second filtration section 45b includes eight partition surfaces 43. The first and second intermediate sections 46a and 46b each include two partition surfaces 43.

[0042] 3 and 6, in the filtration sections 45a, 45b, and 45c, the angle formed between adjacent partition surfaces 43 is greater than 0°. On the other hand, in the intermediate sections 46a and 46b, the angle formed between adjacent partition surfaces 43 is 0°. In other words, in the intermediate sections 46a and 46b, the adjacent partition surfaces 43 overlap each other.

[0043] The overlapping of adjacent partition surfaces 43, 43 increases the structural strength of the intermediate portions 46a, 46b and reduces deflection. As a result, the filter medium 41's shape retention against its own weight and the pressure from the air passing through it is increased, reducing or preventing deflection of the entire filter medium 41. In this way, the strength of the filter 40 is improved. Furthermore, because multiple partition surfaces 43, 43 are overlapped in the intermediate portions 46a, 46b, it is more difficult for air to cross (permeate) the intermediate portions 46a, 46b in the second direction D2 than in the filtration portions 45a, 45b, 45c. Therefore, the risk of air passing through two adjacent filtration portions 45a, 45b; 45b, 45c crossing (permeating) the intermediate portions 46a, 46b in the second direction D2 and mixing with each other is reduced. This reduces the risk that, when two adjacent filtering sections 45a, 45b; 45b, 45c filter different types of air (outside air and inside air), the air that has passed through one of the filtering sections 45a, 45b; 45b, 45c and the air that has passed through the other filtering section 45a, 45b; 45b, 45c will unintentionally mix while passing through the filter 40. In other words, the air separation properties of the filter 40 can be improved.

[0044] The filter 40 is arranged so that the first direction D1 (and therefore the direction in which the first and second intermediate portions 46a, 46b extend) is along the direction in which the first partition 27a and second partition 27b of the air intake housing 20 and the first edge portion 31a and second edge portion 31b of the inlet side end portion 31 of the separation tube 30 extend (front-to-back direction).

[0045] 6, the first intermediate portion 46a is aligned with an end 27aa of the first partition wall 27a of the air intake housing 20, which faces the filter 40, along the direction of airflow passing through the downstream air introduction space 20B of the air intake housing 20. The second intermediate portion 46b is aligned with an end 27ba of the second partition wall 27b of the air intake housing 20, which faces the filter 40, along the direction of airflow passing through the downstream air introduction space 20B. As a result, air flowing into the first upstream air introduction space 20A1 is guided by the first partition wall 27a and the first intermediate portion 46a to pass through the first filtering portion 45a. Similarly, air flowing into the second upstream air introduction space 20A2 is guided by the first partition wall 27a and the first intermediate portion 46a, and the second partition wall 27b and the second intermediate portion 46b to pass through the second filtering portion 45b. Furthermore, the air that has flowed into the third upstream air introduction space 20A3 is guided by the second partition wall 27b and the second intermediate portion 46b to pass through the third filtering portion 45c. This reduces the risk that the air from the first upstream air introduction space 20A1, the air from the second upstream air introduction space 20A2, and the air from the third upstream air introduction space 20A3 will unintentionally mix with each other when they flow from the upstream air introduction space 20A into the filter 40.

[0046] In particular, in the illustrated example, end 27aa of first partition 27a of air intake housing 20 that faces filter 40 and end portions 46aa, 46ba of intermediate portions 46a, 46b on the upstream air introduction space 20A side are aligned along the flow direction of air flowing through downstream air introduction space 20B. This further effectively reduces the risk that the air from first upstream air introduction space 20A1, the air from second upstream air introduction space 20A2, and the air from third upstream air introduction space 20A3 will unintentionally mix together when they flow from the upstream air introduction space 20A into filter 40.

[0047] The first intermediate portion 46a and the second intermediate portion 46b are arranged to be aligned with the inlet end portion 31 of the separation tube 30 in the direction of air flow passing through the downstream air introduction space 20B of the air intake housing 20. In the illustrated example, the first intermediate portion 46a and the second intermediate portion 46b are arranged to be aligned with the first edge portion 31a and the second edge portion 31b of the inlet end portion 31, respectively, in the direction of air flow. As a result, air that has passed through the first and third filtering portions 45a and 45c is guided to flow outside the separation tube 30 by the first intermediate portion 46a and the second intermediate portion 46b and the inlet end portion 31. The air that has passed through the second filtering portion 45b is guided to flow inside the separation tube 30 by the first intermediate portion 46a and the second intermediate portion 46b and the inlet end portion 31. Therefore, the risk of the air that has passed through the first and third filtering sections 45a, 45c and the air that has passed through the second filtering section 45b unintentionally mixing together when flowing from the filter 40 into the blower case 10 is reduced.

[0048] In particular, in the illustrated example, the ends 46ab, 46bb of the first and second intermediate portions 46a, 46b facing the separation cylinder 30 and the first edge portion 31a and the second edge portion 31b of the inlet-side end portion 31 are aligned along the flow direction of air flowing through the downstream air introduction space 20B. This further effectively reduces the risk that the air that has passed through the first and third filtration portions 45a, 45c and the air that has passed through the second filtration portion 45b will unintentionally mix together when flowing from the filter 40 into the fan case 10.

[0049] In the illustrated example, the partition surface 43 of the first and second intermediate portions 46a, 46b is perpendicular to an imaginary plane P defined by the first direction D1 and the second direction D2. Therefore, by disposing the filter 40 in the downstream air introduction space 20B of the air intake housing 20 so that the imaginary plane P intersects the air flowing through the downstream air introduction space 20B, the partition surface 43 of the intermediate portions 46a, 46b can be aligned along the air flow direction. Furthermore, the area of ​​the filter medium 41 occupied by the intermediate portions 46a, 46b can be minimized as viewed in the air flow direction. This reduces the risk of the presence of the intermediate portions 46a, 46b increasing the airflow resistance of the filter 40. Furthermore, the presence of the intermediate portions 46a, 46b reduces the risk of reducing the area (as viewed in the air flow direction) of the filtering portions 45a, 45b, 45c of the filter medium 41 that remove pollutants and unpleasant odors. Furthermore, the intermediate portions 46a and 46b can be formed from the same filter material as the partition surface 43. In other words, the filter 40 having the intermediate portions 46a and 46b can be manufactured without changing the number of parts.

[0050] Such a filter 40 can be easily manufactured with a small number of steps. A method for manufacturing the filter 40 will be described below with reference to Figs.

[0051] First, as shown in Fig. 7, a raw web 41R is prepared by winding up a filter media web 41W into a roll. Next, the filter media web 41W is unwound from the raw web 41R, and mountain folds 42 and valley folds 42 are alternately formed on the filter media web 41W. Partition surfaces 43 are formed between the mountain folds 42 and the valley folds 42. Next, as can be seen from Figs. 7 and 8, the filter media web 41W is cut to a desired length along the first direction D1. This results in a filter media 41 with folds 42 formed thereon.

[0052] Next, from among the partition surfaces 43 divided by the folds 42, the partition surface 43 constituting the first intermediate portion 46a and the partition surface 43 constituting the second intermediate portion 46b are determined. Then, as shown in Fig. 8, the partition surfaces 43 are held so that the angle formed by adjacent partition surfaces 43 in each intermediate portion 46a, 46b is 0° (so that adjacent partition surfaces 43 are closely adjacent to each other). Furthermore, the partition surfaces 43 are held so that the angle formed by adjacent partition surfaces 43 in the filtration portions 45a, 45b, 45c formed by the other partition surfaces 43 is greater than 0°.

[0053] Next, two end plates 48, 49 are prepared. Then, adhesive is applied to both ends in the first direction D1 of the filter medium 41 holding the partition surface 43, and one end plate 48 is bonded to one of the both ends, and the other end plate 49 is bonded to the other of the both ends. This completes the filter 40 shown in FIG. 5. Alternatively, although not shown, both ends in the first direction D1 of the filter medium 41 holding the partition surface 43 may be inserted into an injection molding die, and the end plates 48, 49 may be injection molded to fix the shapes of both ends of the filter medium 41 to the end plates 48, 49. This manufacturing method is sometimes called insert molding.

[0054] Next, the operation of the centrifugal blower 1 shown in FIGS. 1 to 3 will be described.

[0055] In the first operating mode of the centrifugal blower 1, the first to third outside air inlets 21, 22, and 23 are open, and the first to third inside air inlets 24, 25, and 26 are closed. This state is not shown. In this state, outside air introduced from the first outside air inlet 21 and the third outside air inlet 23 into the first upstream air introduction space 20A1 and the third upstream air introduction space 20A3 passes through the first filtering section 45a and the third filtering section 45c of the filter 40, respectively, and then passes through the first passage 30A outside the separation cylinder 30, forming a first air flow that flows into the first blade row of the first impeller 3. Meanwhile, outside air introduced from the second outside air inlet 22 into the second upstream air introduction space 20A2 passes through the second filtering section 45b of the filter 40 and passes through the second passage 30B inside the separation cylinder 30, forming a second air flow that flows into the second blade row of the second impeller 4. The first mode of operation is sometimes referred to as the fresh air mode.

[0056] In the second operating mode, the first outside air inlet 21, the second inside air inlet 25, and the third outside air inlet 23 are open, and the first inside air inlet 24, the second outside air inlet 22, and the third inside air inlet 26 are closed. This state is shown in Figures 1 to 3. In this case, outside air introduced from the first outside air inlet 21 and the third outside air inlet 23 into the first upstream air introduction space 20A1 and the third upstream air introduction space 20A3 passes through the first filtering section 45a and the third filtering section 45c of the filter 40, respectively, and passes through the first passage 30A outside the separation cylinder 30, forming a first air flow that flows into the first blade row of the first impeller 3. Furthermore, the internal air introduced into the second upstream air introduction space 20A2 from the second internal air introduction port 25 passes through the second filtering section 45b of the filter 40, passes through the second passage 30B inside the separation cylinder 30, and forms a second air flow that flows into the second blade row of the second impeller 4. The second operating mode is sometimes called an internal / external air two-layer flow mode.

[0057] The second operating mode (internal / external air two-layer flow mode) is used, for example, when driving in defroster / foot mode. In this mode, relatively low-moisture external air is blown out from the defroster vents in the passenger compartment toward the vehicle's windshield (not shown), and relatively high-moisture internal air is blown out from the foot vents in the passenger compartment toward the feet of the occupants.

[0058] In the third operating mode, the first through third interior air inlets 24, 25, and 26 are open, and the first through third exterior air inlets 21, 22, and 23 are closed. This state is not shown. In this case, the interior air introduced from the first interior air inlet 24 and the third interior air inlet 26 into the first upstream air introduction space 20A1 and the third upstream air introduction space 20A3 passes through the first filtering section 45a and the third filtering section 45c of the filter 40, respectively, and then passes through the first passage 30A outside the separation cylinder 30, forming a first air flow that flows into the first blade row of the first impeller 3. Meanwhile, the interior air introduced from the second interior air inlet 25 into the second upstream air introduction space 20A2 passes through the second filtering section 45b of the filter 40 and passes through the second passage 30B inside the separation cylinder 30, forming a second air flow that flows into the second blade row of the second impeller 4. The third mode of operation is sometimes called the indoor mode.

[0059] When a vehicle air conditioner operates in a dual-phase flow mode, it is required to have a high degree of separation between the first air flow (outside air) and the second air flow (inside air). For example, as described above, when a vehicle air conditioner operates in the dual-phase flow mode, it blows dry outside air onto the windshield to prevent fogging of the windshield. However, if moist inside air is mixed with the outside air blowing onto the windshield, the vehicle air conditioner's effectiveness in preventing fogging of the windshield may be reduced.

[0060] In this regard, the centrifugal blower 1 shown in Figures 1 to 3 is configured to improve the separation of the first air flow and the second air flow, as described above. That is, in the centrifugal blower 1 shown in Figures 1 to 3, the intermediate portions 46a and 46b of the filter 40 separate the air passing through each of the filtering sections 45a, 45b, and 45c of the filter 40. This reduces the risk of unintended mixing of the air passing through the first and third filtering sections 45a and 45c (outside air) and the air passing through the second filtering section 45b (inside air). As a result, when the air conditioner is operated in the inside / outside air two-layer air flow mode, the risk of high-humidity inside air mixing with the air blown against the windshield and impairing the windshield defogging function of the air conditioner is reduced.

[0061] In the above example, each of the intermediate portions 46a, 46b is configured with two partition surfaces 43, but this is not limited thereto. As in the filter 40A shown in Fig. 9, each of the intermediate portions 46a, 46b may include three or more partition surfaces 43. In this case, the strength of the filter 40 is improved, and the air separation properties of the intermediate portions 46a, 46b are also improved.

[0062] In the above-described example, the partition surface 43 of the intermediate portions 46a, 46b is perpendicular to the imaginary plane P, but this is not limited to this. In the example shown in Fig. 10, the partition surface 43 of the intermediate portions 46a, 46b of the filter 40B is inclined with respect to the imaginary plane P. In this case as well, if the ends 27aa, 27ba of the partition walls 27a, 27b of the air intake housing 20 that face the filter 40 and the intermediate portions 46a, 46b are aligned along the flow direction of air passing through the downstream air introduction space 20B of the air intake housing 20, the risk of unintentional mixing of the air from the first upstream air introduction space 20A1, the air from the second upstream air introduction space 20A2, and the air from the third upstream air introduction space 20A3 when they flow from the upstream air introduction space 20A into the filter 40B is reduced. Furthermore, by aligning the intermediate sections 46a, 46b and the inlet end section 31 of the separation tube 30 along the flow direction of the air passing through the downstream air introduction space 20B of the air intake housing 20, the risk of the air that has passed through the first and third filtration sections 45a, 45c and the air that has passed through the second filtration section 45b unintentionally mixing together when flowing from the filter 40B into the blower case 10 is reduced.

[0063] 10, the partition surfaces 43 of the first and second intermediate portions 46a, 46b are inclined with respect to an imaginary plane P so as to approach each other from one side of the imaginary plane P to the other side. When viewed in the direction of airflow through the downstream air introduction space 20B, the upstream air introduction space 20A-side ends 46aa, 46ba of the first and second intermediate portions 46a, 46b are positioned to overlap the first upstream air introduction space 20A1 and the third upstream air introduction space 20A3, respectively. When viewed in the direction of airflow through the downstream air introduction space 20B, the separation tube 30-side ends 46ab, 46bb of the first and second intermediate portions 46a, 46b are positioned to overlap the first edge 31a and the second edge 31b of the inlet end 31 of the separation tube 30, respectively. By arranging the intermediate portions 46a, 46b in this manner, part of the air flowing through the first upstream air introduction space 20A1 and the third upstream air introduction space 20A3 flows into the second filtering portion 45b through gaps between the partition walls 27a, 27b and the intermediate portions 46a, 46b, and then flows into the inside (second passage 30B) of the separation cylinder 30. This effectively reduces the risk that part of the air flowing through the second upstream air introduction space 20A2 will flow into the first filtering portion 45a or the third filtering portion 45c and then into the outside (first passage 30A) of the separation cylinder 30. Therefore, when the air conditioner is operated in the inside / outside air two-layer air flow mode, the risk that humid inside air will mix with the air blown against the windshield and impair the windshield defogging function of the air conditioner is effectively reduced.

[0064] However, when the partition surface 43 of the intermediate portions 46a, 46b is inclined with respect to the imaginary plane P, the positions of the intermediate portions 46a, 46b relative to the partition walls 27a, 27b and the separation tube 30 are not limited to the positions described above. That is, when viewed in the flow direction of air flowing through the downstream air introduction space 20B, the ends 46aa, 46ba of the first and second intermediate portions 46a, 46b on the upstream air introduction space 20A side may be positioned so as to overlap the ends 27aa, 27ba of the first and second partition walls 27a, 27b, respectively, that face the filter 40. Furthermore, when viewed in the flow direction of air flowing through the downstream air introduction space 20B, the ends 46ab, 46bb of the first and second intermediate portions 46a, 46b on the separation tube 30 side may be positioned inside the inlet end 31 of the separation tube 30. In this case, part of the air flowing through the first upstream air introduction space 20A1 and the third upstream air introduction space 20A3 passes through the first and third filtration sections 45a, 45c, and then flows into the inside of the separation cylinder 30 (second passage 30B) through gaps between the intermediate sections 46a, 46b and the inlet end section 31. This also effectively reduces the risk that part of the air flowing through the second upstream air introduction space 20A2 will flow into the outside of the separation cylinder 30 (first passage 30A). Therefore, when the air conditioner is operated in the inside / outside air two-layer air flow mode, the risk that humid inside air will mix with the air blown against the windshield and impair the windshield defogging function of the air conditioner is effectively reduced.

[0065] Alternatively, as viewed in the flow direction of air flowing through the downstream air introduction space 20B, the upstream air introduction space 20A-side end portions 46aa, 46ba of the first and second intermediate portions 46a, 46b may be positioned so as to overlap the first upstream air introduction space 20A1 and the third upstream air introduction space 20A3, respectively. As viewed in the flow direction of air flowing through the downstream air introduction space 20B, the separation tube 30-side end portions 46ab, 46bb of the first and second intermediate portions 46a, 46b may be positioned inside the inlet end portion 31 of the separation tube 30. In this case, part of the air flowing through the first upstream air introduction space 20A1 and the third upstream air introduction space 20A3 flows into the second filtering section 45b through gaps between the partition walls 27a, 27b and the intermediate portions 46a, 46b, and then into the inside of the separation tube 30 (the second passage 30B). Furthermore, a portion of the air flowing through the first upstream air introduction space 20A1 and the third upstream air introduction space 20A3 passes through the first and third filtration sections 45a, 45c, and then flows into the inside of the separation cylinder 30 (the second passage 30B) through gaps between the intermediate sections 46a, 46b and the inlet end section 31. This also effectively reduces the risk that a portion of the air flowing through the second upstream air introduction space 20A2 will flow into the outside of the separation cylinder 30 (the first passage 30A). Therefore, when the air conditioner is operated in the inside / outside air two-layer air flow mode, the risk that humid inside air will mix with the air blown against the windshield and impair the windshield defogging function of the air conditioner is effectively reduced.

[0066] In the first embodiment described above, the filter 40 includes a filter medium 41 in which mountain folds 42 and valley folds 42 are alternately formed, and which has partition surfaces 43 defined by the mountain folds 42 and valley folds 42. The filter 40 also includes end plates 48, 49 fixed to both ends of the filter medium 41 in the direction D1 in which the mountain folds 42 and valley folds 42 extend, to maintain the filter medium 41 in a pleated shape. The filter medium 41 includes a plurality of filtering sections 45a, 45b, 45c arranged along the direction D2 in which the mountain folds 42 and valley folds 42 are arranged, each including a plurality of partition surfaces 43, and intermediate sections 46a, 46b provided between adjacent filtering sections 45a, 45b; 45b, 45c. In the filtering sections 45a, 45b, and 45c, the angle formed by the adjacent partition surfaces 43, 43 is greater than 0°, and in the intermediate sections 46a and 46b, the angle formed by the adjacent partition surfaces 43, 43 is 0°.

[0067] According to this filter 40, the presence of the intermediate portions 46a, 46b improves the strength of the filter 40. Furthermore, this filter 40 can be manufactured using end plates 48, 49 each consisting of a single element. This improves the productivity of the filter 40 and the strength of the filter 40. Furthermore, when two adjacent filtration sections 45a, 45b; 45b, 45c filter different types of air (outside air and inside air), this reduces the risk of the air passing through one of the filtration sections 45a, 45b; 45b, 45c and the air passing through the other filtration section 45a, 45b; 45b, 45c unintentionally mixing while passing through the filter 40. In other words, the air separation capability of the filter 40 can be improved.

[0068] 9 and 10, the intermediate portions 46a, 46b include three or more partition surfaces 43. This improves the strength of the filter 40 and also improves the air separation properties of the intermediate portions 46a, 46b.

[0069] 9, the partition surfaces 43 in the intermediate portions 46a, 46b are perpendicular to the imaginary plane P defined by the direction D1 in which the mountain folds 42 and the valley folds 42 extend and the direction D2 in which the mountain folds 42 and the valley folds 42 are aligned. This allows the partition surfaces 43 of the intermediate portions 46a, 46b to be aligned along the air flow direction when the air passing through the filter 40 flows substantially perpendicular to the imaginary plane P. Furthermore, the area occupied by the intermediate portions 46a, 46b in the filter medium 41 can be minimized when viewed in the air flow direction. This reduces the risk that the presence of the intermediate portions 46a, 46b will increase the airflow resistance of the filter 40. Furthermore, the presence of the intermediate portions 46a and 46b reduces the risk of the area (area as viewed in the air flow direction) of the filtering portions 45a, 45b, and 45c of the filter medium 41 that remove pollutants and unpleasant odors being reduced.

[0070] 10, in the middle portions 46a, 46b, the partition surface 43 is inclined with respect to an imaginary plane P defined by the direction D1 in which the mountain folds 42 and the valley folds 42 extend and the direction D2 in which the mountain folds 42 and the valley folds 42 are aligned. With such a filter 40, when the filter 40 is incorporated into the centrifugal blower 1, it is possible to intentionally cause a portion of one of the two types of air passing through the filter 40 to flow into the air passage of the other type of air, thereby effectively reducing the risk of the other type of air flowing into the air passage of one type of air.

[0071] 9 and 10, the filter medium 41 includes a plurality of filtering sections 45a, 45b, 45c and a plurality of intermediate sections 46a, 46b that are alternately arranged along the direction D2 in which the mountain folds 42 and the valley folds 42 are arranged, and each of the filtering sections 45a, 45b, 45c includes a plurality of partition surfaces 43, 43. Such a filter 40 can reduce the risk of three or more air streams (air streams that have flowed into the first to third upstream air introduction spaces 20A1, 20A2, 20A3) unintentionally mixing and passing through the filter 40.

[0072] 10, the filter medium 41 includes first, second, and third filtering sections 45a, 45b, and 45c, and first and second intermediate sections 46a and 46b, each including a plurality of partition surfaces 43, arranged along the direction D2 in which the mountain folds 42 and the valley folds 42 are arranged. The first intermediate section 46a is disposed between the first and second filtering sections 45a and 45b, and the second intermediate section 46b is disposed between the second and third filtering sections 45b and 45c. In the first and second intermediate sections 46a and 46b, the partition surfaces 43 are inclined from one side of the imaginary plane P to the other side, with respect to the imaginary plane P defined by the direction D1 in which the mountain folds 42 and the valley folds 42 extend and the direction D2 in which the mountain folds 42 and the valley folds 42 are arranged. With such a filter 40, when the filter 40 is incorporated into the centrifugal blower 1, a portion of the air intended to pass through the first and third filtration sections 45a, 45c can be intentionally caused to flow into the air passage 30B for the air intended to pass through the second filtration section 45b, thereby effectively suppressing the risk that the air intended to pass through the second filtration section 45b will flow into the air passage 30A for the air intended to pass through the first and third filtration sections 45a, 45c.

[0073] In the first embodiment described above, the centrifugal blower 1 for a vehicle includes the motor 2, the first impeller 3, the second impeller 4, the blower case 10, the air intake housing 20, and the filter 40. The first impeller 3 has a plurality of blades 3a forming a first circumferential blade row, and is driven to rotate by the motor 2 about a rotation axis Ax extending in the axial direction, to blow air from a space radially inward of the first blade row radially outward. The second impeller 4 has a plurality of blades 4a forming a second circumferential blade row, and is driven to rotate by the motor 2 about the rotation axis Ax, to blow air from a space radially inward of the second blade row radially outward. The blower case 10 includes a first scroll 11 that houses the first impeller 3 and a second scroll 12 that houses the second impeller 4. The first scroll 11 has a first suction port 11a that opens in the axial direction and a first discharge port 11b that opens in the circumferential direction, and air drawn in through the first suction port 11a is discharged from the first discharge port 11b as the first impeller 3 rotates. The second scroll 12 has a second suction port 12a that opens in the axial direction and a second discharge port 12b that opens in the circumferential direction, and air drawn in through the second suction port 12a is discharged from the second discharge port 12b as the second impeller 4 rotates. The air intake housing 20 is connected to the blower case 10, and a filter 40 is housed inside. The air intake housing 20 also has outside air inlets 21, 22, and 23 for taking in outside air from the vehicle, inside air inlets 24, 25, and 26 for taking in inside air from the vehicle, an upstream air inlet space 20A that serves as an air passage between the outside air inlets 21, 22, and 23 and the inside air inlets 24, 25, and 26 and a filter 40, and a downstream air inlet space 20B that houses the filter 40 and serves as an air passage between the upstream air inlet space 20A and the blower case 10. Partition walls 27a and 27b that separate the air introduced from the outside air inlets 21 and 23 and the air introduced from the inside air inlet 25 are provided in the upstream air inlet space 20A. The filter 40 is arranged in the downstream air inlet space 20B so that the imaginary plane P intersects with the air flowing through the downstream air inlet space 20B. Ends 27aa, 27ba of the partition walls 27a, 27b facing the filter 40 and intermediate portions 46a, 46b of the filter 40 are aligned along the flow direction of air flowing through the downstream air introduction space 20B.

[0074] According to the centrifugal blower 1, the air that flows into each space (first to third upstream air introduction spaces 20A1, 20A2, 20A3) separated by the partition walls 27a, 27b is guided by the partition walls 27a, 27b and the intermediate portions 46a, 46b to pass through the corresponding filtering portion (first to third filtering portion 45a, 45b, 45c). This reduces the risk that the air from each space 20A1, 20A2, 20A3 will be unintentionally mixed with each other when it flows into the filter 40.

[0075] In the first embodiment, the first impeller 3 and the second impeller 4 are integrally formed. The partition wall 15 divides the internal space of the integrally formed scroll housing 10a in the axial direction, and the first scroll 11 and the second scroll 12 are formed on both sides of the partition wall 15 in the axial direction. The first scroll 11 is located on one side in the axial direction. The first suction port 11a opens on one side in the axial direction toward the downstream air introduction space 20B. The second scroll 12 is located on the other side in the axial direction. The second suction port 12a opens on one side in the axial direction. The internal space of the first scroll 11 and the internal space of the second scroll 12 are in communication with each other via the second suction port 12a. The centrifugal blower 1 further includes a separation cylinder 30 inserted into the scroll housing 10a. The separation cylinder 30 divides the air flow drawn into the scroll housing 10a through the first suction port 11a into a first air flow passing outside the separation cylinder 30 and a second air flow passing inside the separation cylinder 30. The separation cylinder 30 has an inlet end 31 located on one axial side of the first scroll 11. The separation cylinder 30 also has a body 32 connected to the inlet end 31 and extending axially through the radially inner side of the first suction port 11a and the radially inner side of the first blade row of the first impeller 3. The separation cylinder 30 also has an outlet end 33 that turns the first air flow radially outward to guide it to the first scroll 11 and turns the second air flow radially outward to guide it to the second scroll 12. The inlet end portion 31 and the intermediate portions 46a, 46b of the filter 40 are aligned along the flow direction of the air flowing through the downstream air introduction space 20B.

[0076] According to this centrifugal blower 1, the air that has passed through each of the filtering sections 45a, 45b, and 45c is guided to the outside or inside of the separation cylinder 30 by the intermediate sections 46a and 46b and the inlet-side end section 31. This reduces the risk that the air intended to flow outside the separation cylinder 30 and the air intended to flow inside the separation cylinder 30 will unintentionally mix together when they flow from the filters 40 into the blower case 10.

[0077] <Second embodiment> Next, a second embodiment will be described with reference to FIGS. 11 and 12. FIG. 11 is a diagram showing a meridian cross section of a centrifugal blower 101 according to the second embodiment. The centrifugal blower 101 shown in FIG. 11 differs from the centrifugal blower 1 shown in FIGS. 1 to 3 in that it does not include a separation cylinder 30. The centrifugal blower 101 shown in FIG. 11 also differs from the centrifugal blower 1 shown in FIGS. 1 to 3 mainly in the following respects. First, the blower case 110 includes an outer shell wall 10b that surrounds the first scroll 11 and the second scroll 12. Another difference is that the second suction port 12a of the second scroll 12 opens to the other side in the axial direction. Another difference is that the blower case 110 includes a scroll-side partition wall 10c that separates the space between the first scroll 11 and the filter 140. In the second embodiment shown in FIG. 11, the same parts as those in the centrifugal fan 1 shown in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0078] 11, a centrifugal fan 101 includes a motor 2, a first impeller 3 and a second impeller 4 that are rotationally driven by the motor 2, a fan case 110 that houses the first impeller 3 and the second impeller 4, and an air intake housing 120. The configurations of the motor 2, the first impeller 3, and the second impeller 4 are similar to those of the motor 2, the first impeller 3, and the second impeller 4 shown in FIGS. 2 and 3. However, in the example shown in FIG. 11, the first impeller 3 and the second impeller 4 are configured as separate bodies.

[0079] The blower case 110 has a first scroll 11 that houses the first impeller 3, a second scroll 12 that houses the second impeller 4, an outer shell wall 10b that surrounds the first scroll 11 and the second scroll, and a scroll-side partition wall 10c.

[0080] The configurations of the first scroll 11 and the second scroll 12 are similar to those of the first scroll 11 and the second scroll 12 shown in Figures 2 and 3, except that the second suction port 12a opens to the lower side in the axial direction (the other side in the axial direction). That is, the centrifugal blower 1 shown in Figures 2 and 3 is a single-suction type centrifugal blower, while the centrifugal blower 101 shown in Figure 11 is a double-suction type centrifugal blower.

[0081] In the example shown in FIG. 11 , as described above, the first impeller 3 and the second impeller 4 are configured as separate bodies. The first and second impellers 3 and 4 are integrally molded with the first and second inner deflection members 7 and 8, respectively. The first inner deflection member 7 has a side peripheral portion 7a connected to the lower end of the first impeller 3 and a disk-shaped central portion 7b. The second inner deflection member 8 has a side peripheral portion 8a connected to the upper end of the second impeller 4 and a disk-shaped central portion 8b. Each of the central portions 7b and 8b is connected to the rotating shaft 2a of the motor 2. In the second embodiment, the central portions 7b and 8b do not necessarily have to be disk-shaped, and may have a well-known boss shape.

[0082] Between the outer shell wall 10b and the first scroll 11 and the second scroll 12, an air passage is formed that guides a portion of the air that has flowed into the blower case 110 to the second suction port 12a of the second scroll 12. In the illustrated example, the outer shell wall 10b surrounds the first scroll 11 and the second scroll 12 so as to face the first scroll 11 and the second scroll 12 in the radial direction and face the second scroll 12 in the axial direction, and forms an internal space 110A between the first scroll 11 and the second scroll 12 and serves as an air passage between the internal space of the air intake housing 20 and the second suction port 12a. Hereinafter, the internal space 110A formed between the outer shell wall 10b and the first scroll 11 and the second scroll 12 will also be referred to as the "connection space 110A."

[0083] An air intake housing 120 is disposed on one axial side of the fan case 110. The fan case 110 and the air intake housing 120 may be integrally molded, or may be fabricated separately and then connected by a method such as screwing, bonding, or fitting.

[0084] The internal space (air introduction space) of the air intake housing 120 communicates with the first air inlet 11a and the connection space 110A of the scroll housing 10a. As shown in Fig. 11, the air intake housing 120 has first and second outside air inlets 121, 122 that open generally upward, and first and second inside air inlets 124, 125 that open generally left-right. The first and second outside air inlets 121, 122 are connected to an outlet (not shown) of an outside air introduction passage provided in the vehicle, and can introduce outside air into the air intake housing 120. The first and second inside air inlets 124, 125 open into the vehicle cabin, and can introduce inside air (cabin air) into the air intake housing 120.

[0085] The air introduction space of air intake housing 120 includes upstream air introduction space 120A that communicates with outside air introduction ports 121, 122 and inside air introduction ports 124, 125, and downstream air introduction space 120B that is connected to the other axial side of upstream air introduction space 120A and in which filter 140 is disposed. Upstream air introduction space 120A is partitioned by partition wall 127 that extends in the up-down and front-rear directions. Upstream air introduction space 120A is divided by partition wall 127 into first upstream air introduction space 120A1 that communicates with first outside air introduction port 121, first inside air introduction port 124, and downstream air introduction space 120B, and second upstream air introduction space 120A2 that communicates with second outside air introduction port 122, second inside air introduction port 125, and downstream air introduction space 120B.

[0086] First and second switching doors 128a and 128b are provided in the first and second upstream air introduction spaces 120A1 and 120A2, respectively. In the illustrated example, each switching door 128a and 128b is a type known as a cantilever door, and can be rotated around a pivot axis Cx or Dx extending in the front-rear direction by an actuator (not shown). Each switching door 128a and 128b has a flat door plate 129.

[0087] First switching door 128a provided in first upstream air introduction space 120A1 is movable between a first position where first outside air introduction port 121 is opened and first inside air introduction port 124 is closed, and a second position where first outside air introduction port 121 is closed and first inside air introduction port 124 is opened. By placing first switching door 128a in the first position, it is possible to allow outside air to flow into air intake housing 120 from first outside air introduction port 121 and to block inside air from flowing into air intake housing 120 from first inside air introduction port 124. Furthermore, by placing first switching door 128a in the second position, it is possible to block outside air from flowing into air intake housing 120 from first outside air introduction port 121 and to allow inside air to flow into air intake housing 120 from first inside air introduction port 124. In FIG. 11, the first switch door 128a is located at the first position.

[0088] Further, second switching door 128b provided in second upstream internal space 120A2 is movable between a first position where second outside air inlet 122 is opened and second inside air inlet 125 is closed, and a second position where second outside air inlet 122 is closed and second inside air inlet 125 is opened. By disposing second switching door 128b at the first position, it is possible to allow outside air to flow into air intake housing 120 from second outside air inlet 122 and to block inside air from flowing into air intake housing 120 from second inside air inlet 125. By disposing second switching door 128b at the second position, it is possible to block outside air from flowing into air intake housing 120 from second outside air inlet 122 and to allow inside air to flow into air intake housing 120 from second inside air inlet 125. In FIG. 11, the second switch door 128b is located in the second position.

[0089] The space between the first scroll 11 and the filter 140 is partitioned by a scroll-side partition wall 10c that extends in the up-down and front-rear directions. The scroll-side partition wall 10c separates the space between the first scroll 11 and the filter 140 into a first filter-scroll space 120B1 where the first suction port 11a opens, and a second filter-scroll space 120B1 that communicates with the connection space 110A. A lower end (the other end in the axial direction) of the scroll-side partition wall 10c is connected to an upper surface (one side surface in the axial direction) of the first scroll 11.

[0090] The partition wall 127 of the air intake housing 120 and the scroll-side partition wall 10c are arranged relative to each other as follows: That is, the partition wall 127 and the scroll-side partition wall 10c are arranged relative to each other so that almost all of the air introduced into the air intake housing 120 from the first outside air inlet 121 or the first inside air inlet 124 passes through the first filter-scroll space 120B1, and almost all of the air introduced into the air intake housing 120 from the second outside air inlet 122 or the second inside air inlet 125 passes through the second filter-scroll space 120B2. More specifically, as shown in FIG. 12 , an end (lower end) 127a of the partition wall 127 facing the filter 140 and an end (upper end) 10ca of the scroll-side partition wall 10c facing the filter 140 are aligned in the flow direction (approximately the axial direction) of air flowing through the downstream air inlet space 120B of the air intake housing 120.

[0091] The filter 140 is inserted into a slot or rail (not shown) provided in the air intake housing 120 and is held between the partition wall 127 and the scroll-side partition wall 10c. The filter 140 shown in FIG. 11 is configured similarly to the filters shown in FIGS. 2 and 3. However, the number of filtering sections and intermediate sections included in the filter 140 shown in FIG. 11 is different from that of the filter 40 shown in FIGS. 2 and 3. The filter 140 shown in FIG. 11 includes two filtering sections (first and second filtering sections 145a and 145b) and one intermediate section 146 provided between the two filtering sections 145a and 145b. In each filtering section 145a and 145b, the angle formed between adjacent partition surfaces 43 is greater than 0°. On the other hand, in the intermediate section 146, the angle formed between adjacent partition surfaces 43 is 0°.

[0092] The filter 140 is disposed so that the first direction D1 (therefore, the direction in which the intermediate portion 146 extends) is along the direction in which the partition wall 127 and the scroll-side partition wall 10c extend (the front-rear direction).

[0093] Furthermore, intermediate portion 146 is arranged to be aligned with end portion 127a of partition wall 127 of air intake housing 120, which faces filter 140, in the flow direction of air passing through downstream air introduction space 120B of air intake housing 120. As a result, air that has flowed into first upstream air introduction space 120A1 and air that has flowed into second upstream air introduction space 120A2 are guided by partition wall 127 and intermediate portion 146 to pass through first filtration portion 145a and second filtration portion 145b, respectively. This reduces the risk that air from first upstream air introduction space 120A1 and air from second upstream air introduction space 120A2 will unintentionally mix when they flow from upstream air introduction space 120A into filter 140.

[0094] In particular, in the illustrated example, end 127a of partition wall 127 of air intake housing 120 that faces filter 140 and end 146a of intermediate portion 146 on the upstream air introduction space 120A side are aligned along the flow direction of air flowing through downstream air introduction space 120B. This further effectively reduces the risk that the air from first upstream air introduction space 120A1 and the air from second upstream air introduction space 120A2 will unintentionally mix together when they flow from upstream air introduction space 120A into filter 140.

[0095] Furthermore, the intermediate portion 146 is arranged to be aligned with the end (upper end) 10ca of the scroll-side partition wall 10c that faces the filter 140, along the flow direction of air passing through the downstream air introduction space 120B of the air intake housing 120. As a result, the air that has passed through the first and second filtering portions 145a, 145b is guided by the intermediate portion 146 and the scroll-side partition wall 10c to flow into the first filter-scroll space 120B1 and the second filter-scroll space 120B2, respectively. This reduces the risk that the air that has passed through the first filtering portion 145a and the air that has passed through the second filtering portion 145b will unintentionally mix with each other when they flow from the filter 140 into the blower case 110.

[0096] In particular, in the illustrated example, an end 146b of the intermediate portion 146 facing the scroll-side partition wall 10c and an end (upper end) 10ca of the scroll-side partition wall 10c facing the filter 140 are aligned along the flow direction of air flowing through the downstream-side air introduction space 120B. This further effectively reduces the risk that the air that has passed through the first filtration portion 145a and the air that has passed through the second filtration portion 145b will unintentionally mix together when they flow from the filter 140 into the blower case 110.

[0097] Next, the operation of the centrifugal blower 101 shown in FIG. 11 will be described.

[0098] In the first operating mode of the centrifugal blower 101, the first and second outside air inlets 121 and 122 are open, and the first and second inside air inlets 124 and 125 are closed. This state is not shown in the figure. In this mode, outside air introduced from the first outside air inlet 121 into the first upstream air introduction space 120A1 passes through the first filtering section 145a of the filter 140, the first filter-scroll space 120B1, and the first intake port 11a, forming a first air flow that flows into the first blade row of the first impeller 3. Meanwhile, outside air introduced from the second outside air inlet 122 into the second upstream air introduction space 120A2 passes through the second filtering section 145b of the filter 140, the second filter-scroll space 120B2, the connecting space 110A, and the second intake port 12a, forming a second air flow that flows into the second blade row of the second impeller 4. The first mode of operation is sometimes referred to as the fresh air mode.

[0099] In the second operating mode, the first outside air inlet 121 and the second inside air inlet 125 are open, and the first inside air inlet 124 and the second outside air inlet 122 are closed. This state is shown in FIG. 11 . In this state, outside air introduced from the first outside air inlet 121 into the first upstream air inlet space 120A1 passes through the first filtering section 145a of the filter 140, the first filter-scroll space 120B1, and the first air inlet 11a, forming a first air flow that flows into the first blade row of the first impeller 3. Meanwhile, inside air introduced from the second inside air inlet 125 into the second upstream air inlet space 120A2 passes through the second filtering section 145b of the filter 140, the second filter-scroll space 120B2, the connecting space 110A, and the second air inlet 12a, forming a second air flow that flows into the second blade row of the second impeller 4. The second operating mode is sometimes called the two-phase internal / external air flow mode.

[0100] In the third operating mode, the first and second room air inlets 124 and 125 are open, and the first and second outside air inlets 121 and 122 are closed. This state is not shown in the figures. In this case, room air introduced from the first room air inlet 124 into the first upstream air introduction space 120A1 passes through the first filtering section 145a of the filter 140, the first filter-scroll space 120B1, and the first air inlet 11a, forming a first air flow that flows into the first blade row of the first impeller 3. Meanwhile, room air introduced from the second room air inlet 125 into the second upstream air introduction space 120A2 passes through the second filtering section 145b of the filter 140, the second filter-scroll space 120B2, the connecting space 110A, and the second air inlet 12a, forming a second air flow that flows into the second blade row of the second impeller 4. The third mode of operation is sometimes called the indoor mode.

[0101] 11 and 12, the air passing through each filtering section 145a, 145b of the filter 140 is also separated by the intermediate section 146 of the filter 140. This reduces the risk of unintentional mixing of the air passing through the first filtering section 145a (outside air) and the air passing through the second filtering section 145b (inside air). As a result, when the air conditioner is operated in the inside / outside air two-layer flow mode, the risk of high-humidity inside air mixing with the air blown against the windshield and impairing the windshield defogging function of the air conditioner is reduced.

[0102] In the centrifugal blower 101 of the second embodiment described above, the first scroll 11 is located on one side in the axial direction. The first suction port 11a opens on one side in the axial direction toward the downstream air introduction space 120B. The second scroll 12 is located on the other side in the axial direction. The second suction port 12a opens on the other side in the axial direction. The blower case 110 further includes an outer shell wall 10b that faces the first scroll 11 and the second scroll 12 in the radial direction and surrounds the first scroll 11 and the second scroll 12 so as to face the second scroll 12 in the axial direction. The outer shell wall 10b forms a connection space 110A between the first scroll 11 and the second scroll 12, which serves as an air passage between the downstream air introduction space 120B and the second suction port 12a. The blower case 110 also includes a scroll-side partition wall 10c that separates the space between the first scroll 11 and the filter 140 into a space 120B1 where the first suction port 11a opens and a space 120B2 that communicates with the connecting space 110A. The scroll-side partition wall 10c and the middle portion 146 of the filter 140 are aligned along the flow direction of air flowing through the downstream air introduction space 120B.

[0103] In the centrifugal blower 101, the air that has passed through each of the filtering sections 145a, 145b is guided to the first air inlet 11a and the connection space 110A by the intermediate section 146 and the scroll-side partition wall 10c, respectively. This reduces the risk that the air intended to flow into the first scroll 11 and the air intended to flow into the second scroll 12 will unintentionally mix together when they flow from the filter 140 into the blower case 110. [Industrial Applicability]

[0104] The vehicle blower and filter according to the present invention can be manufactured industrially and can be traded commercially, and therefore have economic value and can be used industrially. [Explanation of symbols]

[0105] 1, 101 Centrifugal blower 2 motors 3 First impeller 4. Second impeller 10, 110 Blower case 10b Outer shell wall 10c Scroll side partition 11 First Scroll 11a First intake port 12 Second Scroll 12a Second intake port 20, 120 Air intake housing 21, 22, 23, 121, 122 Outside air intake 24, 25, 26, 124, 125 Inside air intake 27a, 27b, 127 Bulkhead 30 Separation tube 31 Inlet end 32 Torso 33 Outlet end 40, 40A, 40B, 140 filters 41 Filter media 42 creases 43 ward screen 45a, 45b, 45c, 145a, 145b Filtration section 46a, 46b, 146 middle part 110A connection space P Virtual surface

Claims

1. A centrifugal blower (1;101) for a vehicle, A motor (2), a first impeller (3) having a plurality of blades (3 a) forming a first circumferential blade row, which is rotationally driven by the motor (2) about a rotation axis (Ax) extending in the axial direction, and which blows air in a space radially inside the first blade row radially outward; a second impeller (4) having a plurality of blades (4 a) forming a second circumferential blade row, which is rotationally driven about the rotation axis (Ax) by the motor (2) and blows air in a space radially inside the second blade row radially outward; a blower case (10; 110) including: a first scroll (11) that houses the first impeller (3), the first scroll (11) having a first suction port (11a) that opens in the axial direction and a first discharge port (11b) that opens in the circumferential direction, and that sends out air sucked in from the first suction port (11a) from the first discharge port (11b) as the first impeller (3) rotates; and a second scroll (12) that houses the second impeller (4), the second scroll (12) having a second suction port (12a) that opens in the axial direction and a second discharge port (12b) that opens in the circumferential direction, and that sends out air sucked in from the second suction port (12a) from the second discharge port (12b) as the second impeller (4) rotates; an air intake housing (20; 120) having a filter (40; 40A; 40B; 140) connected to the blower case (10) housed therein, the air intake housing (20; 120) having an outside air inlet (21, 22, 23; 121, 122) for taking in outside air of the vehicle, an inside air inlet (24, 25, 26; 124, 125) for taking in inside air of the vehicle, an upstream air introduction space (20A; 120A) which serves as an air passage between the outside air inlet (21, 22, 23; 121, 122) and the inside air inlet (24, 25, 26; 124, 125) and the filter, and a downstream air introduction space (20B; 120B) which houses the filter and serves as an air passage between the upstream air introduction space (20A; 120A) and the blower case (10; 110); Equipped with The filter is A filter medium (41) having alternating mountain folds (42) and valley folds (42), and having partition surfaces (43) partitioned by the mountain folds (42) and the valley folds (42); End plates (48, 49) fixed to both ends of the filter material (41) in the direction (D1) in which the mountain folds (42) and the valley folds (42) extend, maintaining the filter material (41) in a pleated shape; Equipped with The filter medium (41) includes a plurality of filtering sections (45a, 45b, 45c; 145a, 145b) arranged along the direction (D2) in which the mountain folds (42) and the valley folds (42) are arranged, each of which includes a plurality of partition surfaces (43, 43), and intermediate sections (46a, 46b; 146) provided between adjacent filtering sections, In the filtering section (45a, 45b, 45c; 145a, 145b), the angle formed by the adjacent partition surfaces (43, 43) is greater than 0°, In the intermediate portion (46a, 46b; 146), the angle between the adjacent partition surfaces (43, 43) is 0°; a partition wall (27a, 27b; 127) is provided in the upstream air introduction space (20A; 120A) to separate the air introduced from the outside air introduction port (21, 23; 121) and the air introduced from the inside air introduction port (25; 125); In the downstream air introduction space (20B; 120B), the filter (40; 40A; 40B; 140) is arranged so that an imaginary plane (P) defined by a direction (D1) in which the mountain folds (42) and the valley folds (42) extend and a direction (D2) in which the mountain folds (42) and the valley folds (42) are aligned crosses the air flowing through the downstream air introduction space (20B; 120B), a centrifugal blower (1; 101) in which an end (27aa, 27ba; 127a) of the partition (27a, 27b; 127) facing the filter (40; 40A; 40B; 140) and the middle portion (46a, 46b; 146) of the filter (40; 40A; 40B; 140) are aligned along the flow direction of air flowing through the downstream air introduction space (20B; 120B).

2. 2. The centrifugal blower according to claim 1, wherein the intermediate section (46a, 46b) includes three or more of the partition surfaces (43).

3. 3. A centrifugal blower (1; 101) according to claim 1 or 2, wherein in the intermediate portion (46a, 46b; 146), the partition surface (43) is perpendicular to an imaginary plane (P) defined by the direction (D1) in which the mountain folds (42) and the valley folds (42) extend and the direction (D2) in which the mountain folds (42) and the valley folds (42) are aligned.

4. 3. A centrifugal blower (1; 101) according to claim 1 or 2, wherein in the intermediate portion (46a, 46b), the partition surface (43) is inclined with respect to an imaginary plane (P) defined by the direction (D1) in which the mountain folds (42) and the valley folds (42) extend and the direction (D2) in which the mountain folds (42) and the valley folds (42) are aligned.

5. The filter medium (41) includes a plurality of filtering sections (45a, 45b, 45c) and a plurality of intermediate sections (46a, 46b) that are alternately arranged along a direction (D2) in which the mountain folds (42) and the valley folds (42) are arranged, and each of the filtering sections (45a, 45b, 45c) includes a plurality of partition surfaces (43, 43). A centrifugal blower (1; 101) according to any one of claims 1 to 4.

6. The filter medium (41) includes first, second, and third filtering sections (45a, 45b, 45c) and first and second intermediate sections (46a, 46b) that are aligned along a direction (D2) in which the mountain folds (42) and the valley folds (42) are aligned and each of the filtering sections includes a plurality of the partition surfaces (43), the first intermediate portion (46a) is disposed between the first and second filtering portions (45a, 45b); the second intermediate portion (46b) is disposed between the second and third filtering portions (45b, 45c); 5. The centrifugal blower (1; 101) according to claim 4, wherein in the first and second intermediate portions (46a, 46b), the partition surfaces (43) are inclined relative to an imaginary plane (P) defined by a direction (D1) in which the mountain folds (42) and the valley folds (42) extend and a direction (D2) in which the mountain folds (42) and the valley folds (42) are aligned so as to approach each other from one side of the imaginary plane (P) to the other side.

7. The first impeller (3) and the second impeller (4) are integrally formed, The first scroll (11) and the second scroll (12) are formed on both sides of a partition wall (15) in the axial direction by dividing an internal space of an integrally molded scroll housing (10a) by the partition wall (15), The first scroll (11) is located on one side in the axial direction, The first suction port (11a) opens toward the downstream air introduction space (20B) on one side in the axial direction, The second scroll (12) is located on the other side in the axial direction, The second suction port (12a) opens to one side in the axial direction, The internal space of the first scroll (11) and the internal space of the second scroll (12) are in communication with each other through the second suction port (12a), The centrifugal blower (1) further includes a separation tube (30) inserted into the scroll housing (10a) and dividing the flow of air drawn into the scroll housing (10a) from the first suction port (11a) into a first air flow passing outside the separation tube (30) and a second air flow passing inside the separation tube (30), The separation cylinder (30) has an inlet-side end (31) located on one side of the first scroll (11) in the axial direction, a body portion (32) connected to the inlet-side end (31) and extending in the axial direction passing radially inside the first suction port (11a) and radially inside the first blade row of the first impeller (3), and an outlet-side end (33) that turns the first air flow radially outward to guide it to the first scroll (11) and turns the second air flow radially outward to guide it to the second scroll (12), 2. The centrifugal blower (1) according to claim 1, wherein the inlet end (31) and the intermediate portion (46a, 46b) of the filter (40) are aligned along the flow direction of air flowing through the downstream air introduction space (20B).

8. The first scroll (11) is located on one side in the axial direction, The first suction port (11a) opens toward the downstream air introduction space (120B) on one side in the axial direction, The second scroll (12) is located on the other side in the axial direction, The second suction port (12a) opens to the other side in the axial direction, The blower case (110) further includes: an outer shell wall (10b) surrounding the first scroll (11) and the second scroll (12) so as to face the first scroll (11) and the second scroll (12) in the radial direction and face the second scroll (12) in the axial direction, the outer shell wall (10b) forming, between the first scroll (11) and the second scroll (12), a connection space (110A) which serves as an air passage between the downstream air introduction space (120B) and the second suction port (12a); a scroll-side partition wall (10c) that separates a space between the first scroll (11) and the filter (140) into a space (120B1) to which the first suction port (11a) opens and a space (120B2) that communicates with the connection space (110A), 2. The centrifugal blower according to claim 1, wherein the scroll-side partition wall and the intermediate portion of the filter are aligned along a flow direction of air flowing through the downstream air introduction space.

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