Centrifugal Blower

Abstract

To provide a centrifugal blower that enables a case body to be readily assembled by combining first and second cases together and prevents the case body from causing any backlash after being assembled.SOLUTION: A centrifugal blower includes a first case 4a and a second case 4b of which first fitting part P and second fitting part Q are fitted to each other by convexo-concave means, where a first projection 4g and a second projection 4i of which central lines extend in parallel in an axial direction are overlaid in a radial direction at opposite wall surfaces of the fitting part P and the second fitting part Q and apexes 4g1, 4i1 of the first projection 4g and the second projection 4i are engaged each other while pressing the wall surfaces facing each other in a circumferential direction.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present disclosure relates to a centrifugal blower used, for example, for seat air conditioning or HVAC (Heating, Ventilation, and Air Conditioning) equipment. [Background technology]

[0002] For example, when a driver is in contact with the seat back or seating area for a long time, such as when driving a car for a long distance, the driver feels uncomfortable because hot and humid air clings to the seat back and seating area. For this reason, seat air conditioners are mainly used to harmonize the hot and humid air that tends to accumulate in the seat back and seating area.

[0003] There are two types of seat air conditioners: one that blows air out from the seat, and one that sucks air in from the seat and exhausts it. Here, we will explain the suction type seat air conditioner, which is expected to have a more comfortable air conditioning effect. The suction type seat air conditioner achieves an air conditioning effect by sucking in the hot and humid air trapped in the backrest and seating area and removing it from those areas. The above-mentioned seat air-conditioning device is mounted on a vehicle seat and is expected to be used in harsh conditions, such as being exposed to changes in humidity due to sweating by the passenger and vibrations due to steps or uneven surfaces on the driving surface.

[0004] For example, an electric pump has been proposed that is equipped with a centrifugal fan that realizes waterproofing and low vibration and prevents rattling after assembly. A first gasket is interposed between the stator and motor housing and the support member, and a second gasket is interposed between the support member and the board housing. The first gasket and the second gasket prevent water from entering between the stator and motor housing and the support member, and between the support member and the board housing, ensuring waterproofing. Even if vibrations generated in the stator during operation of the motor unit are transmitted to the motor housing, the vibrations can be absorbed by the first gasket and the second gasket, ensuring low vibration performance. Furthermore, the stator, motor housing, and substrate housing can be attached to the support member using the first snap-fit ​​structure, the second snap-fit ​​structure, and the third snap-fit ​​structure, making assembly easier (Patent Document 1: Japanese Patent No. 6,973,432).

[0005] Also, a structure has been proposed in which the upper casing and the lower casing of the centrifugal fan are joined together by interposing a support between them. Specifically, the support is integrally formed with the upper casing by molding resin (PBT resin) on a flange provided on the outer periphery of the upper casing, and a protrusion is formed at the tip of the support. The protrusion is inserted into a through hole formed in the flange of the lower casing, and the tip of the protrusion protruding from the through hole is welded (for example, ultrasonic welding, vibration welding, laser welding, etc.) or thermally caulked, so that the upper casing and the lower casing are joined together via the support. The upper and lower casings are made of resin and are lightweight, and ribs are formed on each casing to increase rigidity and suppress vibration (Patent Document 2: Japanese Patent No. 7043338). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6973432 [Patent Document 2] Patent No. 7043338 Summary of the Invention [Problem to be solved by the invention]

[0007] In the above-mentioned Patent Document 1, the stator, the motor housing, and the board housing are assembled to the support member using the first snap-fit ​​structure, the second snap-fit ​​structure, and the third snap-fit ​​structure, so that the structure is large in the axial direction and not suitable for thinning, and cannot be used in places where the assembly space is limited, such as inside a vehicle seat. In addition, a gasket is assembled for waterproofing, so that the number of parts is large, the number of steps is increased, and the manufacturing cost is also increased.

[0008] Furthermore, when joining an upper casing and a lower casing made of resin by welding or heat crimping, as in Patent Document 2, the joining portion needs to have a volume large enough to withstand the mechanical stresses that occur when welding or heat crimping is performed, and manufacturing labor is required. [Means for solving the problem]

[0009] The present invention has been made to solve these problems, and its object is to provide a centrifugal blower that allows for simple assembly of a case body formed by combining a first case and a second case, and prevents rattling of the case body after assembly.

[0010] In order to achieve the above object, the present invention has the following configuration. A centrifugal blower in which a centrifugal fan and a motor for driving and rotating the fan are housed in a case body, the case body taking in air from an axial center of the case body and discharging compressed air from a radially outside of the case body, the case body comprising: a first case assembled to cover the centrifugal fan, an intake opening provided in the center and a first air passage formed on the radially outside; and a second case supporting the motor for rotation and having a second air passage formed radially outside of an outer circumferential end of the centrifugal fan to combine with the first air passage, the case body having a first fitting portion provided on the first case and a second fitting portion provided on the second case which are fitted into each other in a concave-convex manner, and a first ridge stripe and a second ridge stripe whose center lines extend parallel to the axial direction are overlapped with each other in the radial direction on opposing wall surfaces of the first fitting portion and the second fitting portion, and a top portion of the first ridge stripe and the top portion of the second ridge stripe are The first fitting portion and the second fitting portion face each otherThe feature of this method is that the walls are pressed together while being assembled. In this manner, the first and second protrusions, whose center lines extend parallel to the axial direction, overlap each other in the radial direction on the opposing wall surfaces of the first and second fitting portions, and the tops of the first and second protrusions are The first fitting portion and the second fitting portion face each other Since the wall surfaces are engaged while being pressed against each other, when the first fitting portion and the second fitting portion are engaged with each other, no rattle occurs in the circumferential and radial directions of the case body, and further in the axial direction.

[0011] A first protrusion having a curved top and continuing in the plate thickness direction may be formed on both circumferential side walls of the first fitting portion, which is provided in a plate-like shape protruding from the outer circumferential edge portion of the first case, and a second protrusion having a narrow opening end and gradually widening toward the bottom side may be formed on both upright walls of the second fitting portion, which is recessed and fits into the first fitting portion. As a result, simply by overlapping the first case and the second case in the axial direction, the first ridges and second ridges fit together while abutting, so no play occurs in the radial direction of the case body, and because the tops of the first ridges and second ridges press against the opposing wall surfaces, no play occurs in the circumferential direction of the case body either. And because the first ridges and second ridges mesh together such that the pressing force is strongest at the fitting position, no play occurs in the axial direction of the case body either.

[0012] The first fitting portion and the second fitting portion may be fitted together to form a lead wire opening through which a lead wire of a motor is drawn out. As a result, when the lead wire opening is formed by mating the first fitting portion and the second fitting portion, by simply forming the first protrusion ridge and the second protrusion ridge on the inner and outer walls of the first fitting portion and the second fitting portion, it is possible to prevent rattling of the case body after assembly of the case body without providing any new parts.

[0013] The case body may be formed by stacking the first case and the second case in the axial direction and engaging an elastically deformable locking piece provided on the outer peripheral side of the first case with a locking portion provided on the outer peripheral side of the second case. This allows the first case and the second case to be assembled by overlapping them in the axial direction and snap-fitting the locking piece so that it elastically deforms and locks into the locking portion, which provides good assembly ease and further enhances the locking state between the locking piece and the locking portion as a result of deeper engagement between the first and second ridges. Effect of the Invention

[0014] It is possible to provide a centrifugal blower in which the case body formed by combining the first case and the second case can be easily assembled and rattling after assembly is prevented. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of a centrifugal blower. [Diagram 2] 2 is a perspective view of the centrifugal blower of FIG. 1 with a first case removed. FIG. [Diagram 3] FIG. 2 is a front view of the first case of FIG. [Figure 4] 4 is an internal plan view of the first case of FIG. 3. [Diagram 5] 2 is a perspective view of a second case and a distribution cable in FIG. 1. [Figure 6] 6 is an internal plan view of the second case of FIG. 5. FIG. [Figure 7] 4 is a cross-sectional view of a lead wire pull-out portion of the case body. FIG. [Figure 8] FIG. 4 is a cross-sectional view of the snap-fit ​​structure of the case body. [Figure 9] FIG. [Figure 10] 4 is a perspective view of a first fitting portion of the first case. FIG. [Figure 11] FIG. 11 is a perspective view of a second fitting portion of the second case. [Figure 12] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of a centrifugal fan according to the present invention will be described with reference to the accompanying drawings. First, a schematic configuration of the centrifugal fan will be described with reference to Figs. 1 to 12. A DC brushless motor is used as the motor M, and an outer rotor type motor is used in this embodiment. However, an inner rotor type motor may also be used.

[0017] As shown in FIG. 1, the centrifugal blower 1 is constructed by assembling a centrifugal fan 2 (see FIG. 2) and a rotor 3 (see FIG. 12) integrally, and a motor M for rotating these is housed in a case body 4. As shown in FIG. 1, air is taken in from the axial center of the case body 4, and pressurized air is exhausted from the radial outside along the axial direction. As shown in FIG. 1, the case body 4 is formed by combining a first case 4a assembled to cover the centrifugal fan 2 with a second case 4b that rotatably supports the motor M (rotor 3 and stator 5; see FIG. 12). The first case 4a and the second case 4b are assembled together by engaging elastically deformable locking pieces 4j provided at multiple points on the outer periphery of the first case 4a with locking parts 4k provided at corresponding positions on the outer periphery of the second case 4b (snap fit).

[0018] FIG. 12 shows a cross-sectional view of a motor M, which is a driving source. As shown in FIG. 12, the stator 5 has a stator core 7 bonded to the outer periphery of the axial center of a stator housing 6 formed in a cylindrical shape. The stator core 7 is assembled by inserting the stator housing 6 into the center hole of the annular core back portion 7a. The stator core 7 is abutted against a stepped portion 6g provided on the stator housing 6, and is positioned in the axial direction and assembled. The stator core 7 has a plurality of pole teeth 7b protruding radially outward from the core back portion 7a. The pole teeth 7b are covered with an insulator 7c, and a motor coil 7d is wound around the pole teeth 7b. The coil lead of the motor coil 7d is soldered to a terminal portion of a motor board 12 and electrically connected. The motor board 12 is assembled by overlapping it on the base plate 11 with the stator housing 6 inserted into the board through hole 12a.

[0019] The rotor 3 is integrally assembled by press-fitting, gluing, shrink-fitting, or a combination of these methods into the hub 3b of the rotor yoke 3a formed in a cup shape, with one end of the rotor shaft 3c. An annular rotor magnet 3d, which is magnetized with alternating north and south poles, is assembled to the inner peripheral surface of the rotor yoke 3a. The rotor yoke 3a is insert-molded together with the impeller 2c. The rotor shaft 3c is inserted into the cylindrical hole 6a of the stator housing 6, and press-fitted into the cylindrical hole 8a of the sintered oil-impregnated bearing 8, which is press-fitted into the fixed housing 6. The insertion end of the rotor shaft 3c is supported by being abutted against a thrust receiver 6c supported by a closing member 6b that closes the cylindrical hole 6a of the stator housing 6. The closing member 6b is abutted against a recess 6d of the stator housing 6, and assembled integrally. A retaining washer 6e is fitted near the insertion end of the rotor shaft 3c to prevent the rotor shaft 3c from coming off in the axial direction. The closing member 6b is sealed by filling a recess 6d of the stator housing 6 with a sealant 6f.

[0020] As shown in FIG. 2, the centrifugal fan 2 has a dome-shaped main plate 2b that is connected to the hub 2a radially outward. The air taken in through the intake opening 4c facing the hub 2a of the centrifugal fan 2 can be pressurized and sent out toward the annular air passage provided radially outward by the impeller 2c formed on the main plate 2b. A shroud 2d connected in an annular shape is formed on the outer circumferential upper end of the impeller 2c. In addition, the hub 2a of the centrifugal fan 2 and the main plate 2b connected thereto form a dome-shaped space on the opposite side to the intake opening 4c. As shown in FIG. 12, the rotor 3 and the stator 5 of the motor M are housed in the dome-shaped space, overlapping in the axial direction. This reduces the axial dimension of the centrifugal blower 1, making it possible to make the centrifugal blower 1 smaller and flatter even if it has the same size.

[0021] As shown in Fig. 1, an intake opening 4c is provided in the center of the first case 4a, and a first air passage 4d is formed on the radially outer side as shown in Fig. 4. The center of the intake opening 4c does not need to strictly coincide with the axis of the rotor shaft 3c of the motor M, as long as the position of the intake opening 4c is near the axial center of the case body 4 and within a range where the centrifugal fan 2 can operate without reducing efficiency. 3 and 4, a plate-shaped first fitting portion P protrudes from the outer circumferential edge portion of the first case 4a. First protrusions 4g are provided on both circumferential side surfaces of the first fitting portion P such that their center lines are parallel to the axial direction.

[0022] As shown in FIG. 5 and FIG. 6, a second air passage 4e is formed on the radial outside of the second case 4b, which is combined with the first air passage 4d. The first case 4a and the second case 4b are combined to form an annular air passage on the radial outside of the case body 4. The second air passage 4e is formed on the bottom outer periphery of the second case 4b, and exhaust holes 4f are drilled at multiple locations in the circumferential direction to exhaust the pressurized compressed air along the axial direction. A plurality of diffuser plates 4r are installed between a bottom outer periphery wall 4h1 and a bottom inner periphery wall 4h2 provided on the bottom of the second case 4b, and exhaust holes 4f are formed. The diffuser plates 4r exhaust the air exhausted in the axial direction from the exhaust holes 4f provided in the second air passage 4e diagonally downward with respect to the rotation direction of the centrifugal fan 2 along the inclination of each diffuser plate 4r. As shown in FIG. 12, a sheet metal base plate 11 that covers the bottom of the motor is attached to the second case 4b. The stator housing 6 is resistance welded to the base plate 11 and assembled together. The motor board 12 is attached to the stator housing 6 in a state where the stator housing 6 is inserted into the board through hole 12a. The motor board 12 has a current-carrying circuit formed thereon.

[0023] As shown in FIG. 5 and FIG. 6, a second fitting portion Q is provided on the outer circumferential side of the second case 4b. The second fitting portion Q is a groove-shaped second fitting portion Q having upright walls on both sides of the bottom and an open top. The second fitting portion Q has a second ridge 4i on the opposing surfaces of the upright walls Q1 on both sides so that the center line is parallel to the axial direction. When the first case 4a and the second case 4b are fitted together, the first fitting portion P and the second fitting portion Q are fitted together, the first ridge 4g and the second ridge 4i overlap each other in the radial direction, and the tops of the first ridge 4g and the second ridge 4i press against the wall surfaces facing each other in the circumferential direction and engage with each other. The first fitting portion P and the second fitting portion Q are fitted together to form a lead wire opening 4q through which the motor lead wire 4p is drawn (see FIG. 9). As shown in FIG. 1 and FIG. 7, the lead wire 4p is drawn from the lead wire opening 4q. A connector terminal 4p1 for wiring connection is provided at the tip of the lead wire 4p.

[0024] As shown in Fig. 10, first protrusions 4g, which have curved surfaces bulging out like a rugby ball, are provided on both circumferential side walls P1 of the first fitting portion P in the plate thickness direction. Also, as shown in Fig. 11, second protrusions 4i, which are narrow at one axial end (opening side) and gradually widen toward the other axial end (bottom side), are formed on the opposing surfaces of both circumferential upright walls Q1 of the second fitting portion Q. The first protrusions 4g and the second protrusions 4i are provided with centerlines extending parallel to the axial direction, and the first protrusions 4g and the second protrusions 4i overlap each other in the radial direction, with the apex portions 4g1 pressing against the opposing wall surface Q1 and the apex portions 4i1 pressing against the opposing wall surface P1, and engaging with each other while pressing the apex portions and wall surfaces opposing each other in the circumferential direction (see Fig. 9). When the first fitting portion P and the second fitting portion Q are fitted together in this manner, no rattle occurs in the circumferential direction, radial direction, and further in the axial direction of the case body 4.

[0025] Specifically, first protrusions 4g, whose center lines are parallel to the axial direction, whose tops 4g1 are curved, and which extend in the thickness direction, are respectively provided on both circumferential side walls P1 of the first fitting portion P. The first protrusions 4g do not necessarily have to have the same width in the thickness direction, and may have different widths in the thickness direction. Also, second protrusions 4i, whose center lines are parallel to the axial direction, whose tops 4i1 are curved, which are narrow at one axial end side (opening side) and gradually wider at the other axial end side (bottom side), are respectively provided on opposing upright walls Q1 on both circumferential sides of the second fitting portion Q.

[0026] As a result, simply by overlapping the first case 4a and the second case 4b in the axial direction, the first ridges 4g and the second ridges 4i fit together while abutting in the radial direction, so no rattle is generated in the radial direction of the case body 4, and the tops 4g1 of the first ridges 4g press against the opposing wall surface Q1, and the tops 4i1 of the second ridges 4i press against the opposing wall surface P1, and they fit together while pressing against their opposing tops and wall surfaces, so no rattle is generated in the circumferential direction of the case body 4. Also, the first ridges 4g fit together along the inclined surfaces of the second ridges 4i, which are formed so that the opening side is narrow and the bottom side gradually becomes wider, and the meshing between the ridges is strongest at the fitting position, so no rattle is generated in the axial direction of the case body 4.

[0027] In addition, since the first ridges 4g mesh more strongly along the tapered inclined surfaces of the second ridges 4i that are narrow on the opening side and wide on the bottom side, the first case 4a is pressed more strongly inward in the radial direction, and the second case 4b is pressed more strongly outward in the radial direction, as shown by the arrows in Fig. 9. This provides the advantage of further strengthening the engagement between the locking pieces 4j and the locking portions 4k that form the snap fit.

[0028] In this way, the lead wire opening 4q is formed by mating the first fitting portion P and the second fitting portion Q. Therefore, by simply forming the first protrusion 4g and the second protrusion 4i on the inner and outer walls of the first fitting portion P and the second fitting portion Q, it is possible to prevent rattling after assembly of the case body 4 without providing any new parts.

[0029] Furthermore, the elastically deformable locking pieces 4j provided on the outer periphery of the first case 4a lock into locking portions 4k provided on the outer periphery of the second case 4b, thereby assembling the case body 4. At this time, the first case 4a and the second case 4b are overlapped in the axial direction, and the locking pieces 4j are elastically deformed and locked into the locking portions 4k by snap-fit ​​assembly, which provides good assembly ease and further enhances the locking state between the locking pieces 4j and the locking portions 4k as the meshing between the first ridges 4g and the second ridges 4i deepens.

[0030] The above embodiment has been described by taking an in-vehicle seat air conditioner as an example, but the present invention is not limited thereto and may be used in a centrifugal blower for HVAC (heating, ventilation, and air conditioning), etc. It goes without saying that the present invention can be similarly applied to places other than vehicles where there is little excess space and it is difficult to secure space for installing a conventional air conditioner blower. [Explanation of symbols]

[0031] REFERENCE SIGNS LIST 1 Centrifugal blower 2 Centrifugal fan 2a Hub 2b Main plate 2c Impeller 3 Rotor 3a Rotor yoke 3b Hub 3c Rotor shaft 3d Rotor magnet 4a First case 4b Second case 4c Intake opening 4d First air passage 4e Second air passage 4f Exhaust hole 4g ​​First ridge 4g1, 4i1 Top 4i Second ridge 4h1 Bottom outer peripheral wall 4h2 Bottom inner peripheral wall 4j Locking piece 4k Locking portion 4r Diffuser 4p Lead wire 4q Lead wire opening P First fitting portion P1 Side wall Q Second fitting portion Q1 Upright wall 5 Stator 6 Stator housing 6a Cylindrical hole 6b Closing member 6c Thrust receiver 6d Recess 6e Anti-slip washer 6f Sealing material 6g Stepped portion 7 Stator core 7a Core back portion 7b Pole teeth 7c Insulator 7d Motor coil 8 Sintered oil-impregnated bearing 8a Cylindrical hole 11 Base plate 12 Motor board 12a Board through hole

Claims

1. A centrifugal blower in which a centrifugal fan and a motor for rotating the fan are housed in a case body, the centrifugal blower takes in air from a center part of the case body in an axial direction and exhausts compressed air from an outer side of the case body in a radial direction, the case body includes a first case that is assembled to cover the centrifugal fan and has an intake opening at its center and a first air passage formed radially outward; and a second case that rotatably supports the motor and has a second air passage formed radially outward from an outer circumferential end of the centrifugal fan to be combined with the first air passage, the case body is assembled in such a manner that a first fitting portion provided on the first case and a second fitting portion provided on the second case are fitted into each other by projection and recess, first ridges and second ridges having center lines extending parallel to the axial direction are overlapped in the radial direction on opposing wall surfaces of the first fitting portion and the second fitting portion, and top portions of the first ridges and second ridges are engaged with each other while pressing against the opposing wall surfaces of the first fitting portion and the second fitting portion.

2. 2. The centrifugal blower according to claim 1, wherein a first ridge having a curved top and continuing in a plate thickness direction is formed on both circumferential side walls of the first fitting portion which is provided in a plate-like shape and protrudes from the outer circumferential edge portion of the first case, and a second ridge having a narrow opening end and gradually widening toward a bottom side is formed on both upright walls of the second fitting portion which is recessed and fits into the first fitting portion.

3. 3. The centrifugal blower according to claim 1, wherein the first fitting portion and the second fitting portion are fitted together to form an outlet wire opening through which an outlet wire of a motor is drawn out.

4. 3. The centrifugal blower according to claim 1 or claim 2, wherein the case body is formed by stacking the first case and the second case in the axial direction and engaging an elastically deformable locking piece provided on the outer circumferential side of the first case with a locking portion provided on the outer circumferential side of the second case.

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