JP2017158272A - Blower motor unit for air conditioning - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cooling efficiency in a blower motor unit for air conditioning which includes a brushless motor.SOLUTION: A motor unit includes: a brushless motor 4; an electronic substrate 5 which drives the brushless motor 4; a casing 2 which houses the brushless motor 4 and the electronic substrate 5; and a heat dissipation member 6 connected with the electronic substrate 5. The heat dissipation member 6 has: a first radiation part 60 exposed to the outside of the casing 2; and a second heat radiation part disposed in the casing.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a blower motor unit of an air conditioner mounted on a vehicle such as an automobile.

  For example, Patent Document 1 discloses a load-integrated drive device that is used as a blower fan for blowing air from an air conditioner. This load-integrated drive device includes a heat radiating plate on a plate surface on the upper surface side of the package. According to such a load-integrated drive device of Patent Document 1, the inside of the load-integrated drive device can be cooled by the heat sink discharging heat inside the package to the outside.

JP 2004-350376 A

  However, in such a load-integrated drive device (motor unit) disclosed in Patent Document 1, there is only one surface of the heat dissipation plate that can dissipate heat. In addition, in a motor unit used for a blower fan or the like, it is considered to use a brushless motor for miniaturization. In a motor unit using a brushless motor, electronic components are concentrated on a circuit board, and the temperature tends to rise, so a cooling method with higher cooling efficiency is required.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to improve cooling efficiency in an air-conditioning blower motor unit including a brushless motor.

  In order to achieve the above object, in the present invention, as a first means related to an air conditioning blower motor unit, a brushless motor, an electronic board that drives the brushless motor, a casing that houses the brushless motor and the electronic board, And a heat radiating member connected to the electronic substrate, wherein the heat radiating member includes a first heat radiating portion exposed to the outside of the casing and a second heat radiating member disposed inside the casing. The structure of having a part is adopted.

  As a second means related to the air conditioner blower motor unit, in the first means, the electronic circuit board further includes a heat transfer member that conducts heat of the electronic board to the heat radiating member. The structure of being inserted between heat radiating members is employ | adopted.

  As a third means related to the air conditioning blower motor unit, in the second means, the electronic board is formed with a thermal hole for conducting heat at a position in contact with the heat transfer member. adopt.

  As a fourth means related to the air-conditioning blower motor unit, in any one of the first to third means, the casing has an introduction opening for taking outside air into the interior, and air flowing in from the introduction opening. A configuration is adopted in which a discharge opening for discharging to the outside is provided, and the heat radiating member is disposed in a streamline of air flowing from the introduction opening to the discharge opening.

  As a fifth means related to the air conditioning blower motor unit, in any one of the first to fourth means, the heat radiating member is formed by integrally forming the first heat radiating portion and the second heat radiating portion, and a flange portion. Further, the first heat radiating portion and the second heat radiating portion are configured to be smaller in shape than the flange portion in plan view.

  As a sixth means related to the air-conditioning blower motor unit, in the fifth means, the second heat radiating portion has a substantially rectangular parallelepiped base and a triangular rib protruding from the side surface of the base. Adopt the configuration.

  As a seventh means related to the air conditioning blower motor unit, in any one of the first to sixth means, the casing has an opening through which the heat radiating member is inserted, and an edge of the opening and the heat radiating member A structure is provided that includes a seal portion that seals the gap.

  As an eighth means related to the air conditioning blower motor unit, in the seventh means, a base frame fixed to the inside of the casing and supporting the electronic board and the heat radiating member, and the base frame fixed to the casing. The structure which is further provided with the elastic member inserted between the said base frame and the said casing in the position to be carried out is employ | adopted.

  According to this invention, the heat radiating member has the 1st heat radiating part and the 2nd heat radiating part. Accordingly, heat can be radiated from the first heat radiating portion to the outside of the casing, and heat can be radiated from the second heat radiating portion to the inside of the casing. Therefore, the heat of the electronic substrate which is a heat generation source in the motor unit can be efficiently discharged, and the cooling efficiency of the motor unit can be improved.

It is a side view of the air blower provided with the motor unit which concerns on one Embodiment of this invention. It is a perspective view of a motor unit concerning one embodiment of the present invention. It is sectional drawing of the motor unit which concerns on one Embodiment of this invention. It is a figure which shows the internal structure of the motor unit which concerns on one Embodiment of this invention, (a) is the bottom view which abbreviate | omitted the lower casing part, (b) is the top view which abbreviate | omitted the upper casing part. It is a disassembled perspective view containing a part of motor and base frame in one Embodiment of this invention. It is a perspective view of the heat radiating member in one Embodiment of this invention. It is a schematic diagram of the metal mold | die of the heat radiating member and heat radiating member in one Embodiment of this invention, (a) is a side view, (b) is the perspective view which removed the upper metal mold | die. It is the elements on larger scale of sectional drawing of the motor unit of FIG.

  Hereinafter, an embodiment of a blower motor unit 1 (air-conditioning blower motor unit) according to the present invention will be described with reference to the drawings.

The blower A is disposed in the middle of a duct constituting the vehicle air conditioner. Such a blower A includes a blower motor unit 1, a blower fan B, and a fan case C that houses the blower fan B. The blower fan B is a centrifugal fan having a large number of blades on the outer periphery. The blower fan B is rotated by the blower motor unit 1, thereby sucking air from an air suction port C <b> 1 formed in the fan case C and blowing it through an air delivery port (not shown). The fan case C is attached to the blower motor unit 1 via a bracket D. Although not shown, air-conditioning equipment such as an evaporator that cools the air and a heater core that heats the air is disposed on the downstream side in the blowing direction of the air blown from the blower fan B.
In the following description, the side where the blower fan B is attached to the blower motor unit 1 is described as the upper side.

  The blower motor unit 1 is an air-conditioning blower motor unit provided in the blower A, and includes a casing 2, a base frame 3, a motor 4, a circuit board 5, a heat radiating member 6, and an elastic member 7 as shown in FIGS. 2 and 3. ing. The casing 2 includes a casing portion 20 that houses the base frame 3, the motor 4, the circuit board 5, the heat radiating member 6, and the elastic member 7, and a gas guide portion 21. The casing part 20 and the gas guide part 21 are integrally configured by combining the upper casing part 2A and the lower casing part 2B which are divided into two parts in the vertical direction on the peripheral surface part 20b. The upper casing portion 2A is an upper member including an upper surface portion 20a and an introduction opening portion 21a described later, and the lower casing portion 2B is a lower member including a bottom surface portion 20c described later.

  The casing part 20 is a flat, substantially cylindrical container-like part having an upper surface part 20a, a peripheral surface part 20b, and a substantially circular bottom surface part 20c. The casing portion 20 includes a central opening portion 20d opened on the upper surface portion 20a, a heat radiating member exposed opening portion 20e, a projection portion 20f provided on the upper surface portion 20a, and a guide wall portion 20g provided on the bottom surface portion 20c. (See FIG. 4).

  The central opening 20d is an opening formed in the central portion of the upper surface portion 20a that houses the motor 4 and communicates the inside of the casing 2 and the inside of the fan case C that houses the blower fan B. That is, the central opening 20d exposes the motor 4 to the fan case C side. The heat radiating member exposed opening 20e shakes the first heat radiating portion 60 of the heat radiating member 6 formed at a position corresponding to the heat radiating member 6 disposed approximately in the middle between the output shaft 42 of the upper surface portion 20a and the introduction opening 21a. It is an opening that is loosely fitted. The heat radiating member exposed opening 20e is provided to expose the first heat radiating portion 60 of the heat radiating member 6 to the outside of the casing 2 so as to be exposed to the fan case C side.

  The protruding portion 20f is a cylindrical portion that is formed to protrude from the upper surface portion 20a of the upper casing portion 2A downward (inside the casing 2) at a plurality of locations (three locations). As shown in FIG. 4, the guide wall portion 20 g is a standing wall portion that is raised from the bottom surface portion 20 c of the lower casing portion 2 </ b> B, and has a tapered shape at a position opposite to the gas guide portion 21, and is tapered. Form a surface. The guide wall portion 20g flows in from the introduction opening portion 21a and guides the flow of air that has passed under the output shaft 42 along the lower casing portion 2B to the central opening portion 20d, as will be described later.

  As shown in FIG. 1, the gas guide portion 21 is an air conduction path that opens toward the upper side of the casing 2, and communicates the downstream side in the air blowing direction of the fan case C and the inside of the casing 2.

  The base frame 3 supports a plurality of fitting openings 30 into which the elastic member 7 is recessed, a motor holding portion 31 that holds the motor 4 via a shaft support member 43 described later, and the heat dissipation member 6. This is a holding member having a heat radiating member fixing portion 32. The base frame 3 further includes a circuit board fixing portion 35 that fixes the circuit board 5. Such a base frame 3 is elastically supported by the upper casing portion 2A by fitting a plurality of elastic members 7 to the protruding portions 20f.

  In addition, a predetermined gap is provided between the heat radiation member exposed opening 20e of the base frame 3 and the outer peripheral edge of the first heat radiation part 60 of the heat radiation member 6, and a frame-like shape is provided in the gap. The elastic member 7a is sandwiched. Thus, the base frame 3 is elastically supported (floating) by inserting the plurality of elastic members 7 and 7 a inside the casing 2. The elastic member 7 is fixed to the upper casing portion 2A by a fastening member such as a screw, and does not fall off from the protruding portion 20f.

  As shown in FIGS. 4 and 5, the motor 4 and the heat radiating member 6 are attached to a surface (hereinafter referred to as a surface) on the upper casing portion 2 </ b> A side of the base frame 3, and the circuit board 5 is attached to the base frame 3. It is attached to the surface (hereinafter referred to as the back surface) on the lower casing portion 2B side. The motor holding portion 31 is a circularly recessed portion along the shape of the motor 4 attached to the surface, and an output shaft opening 31a through which the output shaft is inserted at the center of the circularly recessed portion, and a frame opening A portion 33 (33a, 33b) and a lower ball bearing holding portion 34 are formed.

  The frame opening 33 has a semicircular range corresponding to a slot position of a board side opening 33a formed at a position corresponding to a notch 50 of the circuit board 5 to be described later and a tooth part 40f of the motor 4 to be described later. And a motor side opening 33b which is a plurality of fan-shaped openings arranged in a row. The substrate side opening 33a and the motor side opening 33b are configured such that the air flow introduced between the lower casing part 2B and the base frame 3 from the introduction opening 21a enters the central opening 20d of the upper casing part 2A. It is provided so as not to hinder heading. The lower ball bearing holding portion 34 is a cylindrical bearing boss formed on the back surface of the motor holding portion 31 and around the output shaft opening portion 31 a, and above the lower ball bearing holding portion 34. The shaft support member 43 (see FIG. 3) is fixed.

  As shown in FIG. 3, the shaft support member 43 includes a lower ball bearing 43c, an upper ball bearing 43b, and a sleeve member which are held by the lower ball bearing holding portion 34 so as to be slidable in the direction of the output shaft 42. 43a. The sleeve member 43a is an annular member that is provided between the stator core 40a and the upper ball bearing 43b and fixes the upper ball bearing 43b to the stator core 40a. The sleeve member 43 a is fixed to the upper surface side of the lower ball bearing holding portion 34 of the base frame 3 while the output shaft 42 is inserted through the central opening in a non-contact manner.

  In the upper ball bearing 43b, the output shaft 42 is press-fitted and fixed to the inner ring portion of the ball bearing, and the sleeve member 43a is fitted and fixed to the outer ring portion of the upper ball bearing 43b. The output shaft 42 is rotatably supported. In the lower ball bearing 43c, the output shaft 42 is press-fitted and fixed to the inner ring portion, and the outer ring portion is inserted into the lower ball bearing holding portion 34 of the base frame 3 so as to be slidable in the direction of the output shaft 42. 42 is rotatably supported. In such a shaft support member 43, the upper ball bearing 43b and the lower ball bearing 43c are energized between the outer ring of the lower ball bearing 43c and the lower ball bearing holding portion 34, respectively. A wave washer 43d is interposed to apply a predetermined pressure to the ball bearing.

  The motor 4 is a three-phase AC brushless motor that is pivotally supported on the base frame 3 via a pivotal support member 43 that will be described later. The motor 4 includes a stator 40, a rotor 41, and an output shaft 42. The stator 40 of the motor 4 includes a stator core 40a, an upper insulator 40b, a lower insulator 40c, and a winding 40d. Furthermore, the stator core 40a includes a yoke portion 40e and a teeth portion 40f. The yoke portion 40e is an annular member, and the sleeve member 43a is press-fitted and fixed inside. Thereby, the stator 40 is fixed to the base frame 3. The yoke portion 40e has a plurality of yoke openings 40g. The teeth portion 40f is formed so as to project radially from the outer periphery of the yoke portion 40e in a direction perpendicular to the output shaft 42, and a plurality of field portions for generating a rotating magnetic field in the circumferential direction around the output shaft 42 It is. In the present embodiment, a configuration in which the tooth portion 40f has 15 slots is illustrated.

  The upper insulator 40b and the lower insulator 40c are resin insulating members provided so as to cover the surface of the stator core 40a. When the upper insulator 40b and the lower insulator 40c sandwich the stator core 40a from the vertical axis direction, the winding 40d and the stator core 40a are insulated. The winding 40d is wound around the tooth portion 40f a plurality of times with the upper insulator 40b and the lower insulator 40c interposed therebetween. The winding 40d is a thin metal wire (copper wire) whose surface is covered with an insulating coating layer such as enamel. The upper insulator 40b is formed with an upper insulator opening 40h at a position overlapping the yoke opening 40g of the yoke 40e. Similarly, a lower insulator opening 40k is formed at a position overlapping the yoke opening 40g in the lower insulator 40c. Accordingly, the yoke opening 40g, the upper insulator opening 40h, and the lower insulator opening 40k are arranged so as to overlap each other, thereby forming a gas flow path 4A inside the motor 4 as shown in FIG. Is done.

  As shown in FIG. 5, in the lower insulator opening 40k of the lower insulator 40c, the portion corresponding to the board side opening 33a of the base frame 3 is directed from the peripheral wall of the lower insulator opening 40k to the lower side of the motor 4. Thus, an L-shaped winding locking portion 40m is formed. The winding 40d is entangled with the winding locking portion 40m, and is drawn out to the lower side of the motor 4 by being inserted through the board side opening 33a along the axis of the output shaft 42.

  The rotor 41 is a rotating member (outer rotor) outside the stator that is externally fitted to and connected to the output shaft 42 on the upper side of the stator 40 and is rotatably provided around the stator 40. As shown in FIG. 5, the rotor 41 is arranged so that a circular upper surface portion 41 c and a peripheral surface portion 41 d are formed, and an inner surface of the peripheral surface portion 41 d is opposed to the stator 40. A plurality of magnets 41b are provided. The frame portion 41a has an output shaft fixing portion 41e to which the output shaft 42 is inserted and fixed at the center of the upper surface portion 41c. The frame portion 41a has a plurality of rotor openings 41f formed in an annular shape around the output shaft fixing portion 41e. The magnets 41b are arranged in a plurality of rows on the inner side of the peripheral surface portion 41d of the frame portion 41a so as to constitute a plurality of magnetic poles facing each other through a predetermined gap in the outer circumferential direction of the stator core 40a. In the present embodiment, the configuration of 14 magnets 14b (14 poles) is illustrated. The circular upper surface portion 41c of the rotor 41 is exposed from the central opening 20d of the upper casing portion 2A.

  The circuit board 5 has a substantially semicircular shape as shown in FIG. 4, and is fixed to the circuit board fixing portion 35 of the base frame 3 with a plurality of screw members. Further, as shown in FIG. 3, the circuit board 5 is supported by the base frame 3 to be separated from the casing 2 inside the casing 2. The circuit board 5 is disposed between the introduction opening 21 a of the casing 2 and the output shaft 42 of the motor 4 in the axial direction of the output shaft 42 of the motor 4. That is, the circuit board 5 is accommodated in the casing 2 and supported by the base frame 3 so as to be eccentric with respect to the output shaft 42. Thereby, the circuit board 5 is arrange | positioned in the streamline of the air which flows from the introduction opening part 21a to the center opening part 20d.

  The circuit board 5 has a notch 50 formed at a portion corresponding to the board-side opening 33 a of the base frame 3 in the vicinity of the output shaft 42. Further, the circuit board 5 includes a connection terminal 51 adjacent to the notch 50. The connection terminal 51 has a connection recess that opens in one side in a substantially U shape when the end of the winding 40d of the motor 4 is not connected. The motor 4 and the circuit board 5 are electrically connected to each other when the end of the winding 40d of the motor 4 drawn out to the lower side of the motor 4 through the board-side opening 33a is sandwiched between the connection recesses. It is connected to the.

  The circuit board 5 and the electronic component mounted on the circuit board 5 correspond to the electronic board of the present invention. In addition, the circuit board 5 has a thermal pad 81 (see FIG. 8) at a position where a large heat generating electronic component such as a switching element is disposed.

  As shown in FIG. 8, the thermal pad 81 is disposed on the upper side surface of the circuit board 5 and the thermal pad 81 a that comes into contact with an electronic component that generates a large amount of heat on the lower side surface of the circuit board 5. The thermal pad 81b is connected to the heat radiating member 6 so as to conduct heat. The circuit board 5 is provided so as to penetrate the substrate material of the circuit board 5 at a position where the thermal pad 81 is provided, and a thermal hole 80 which is a member that thermally connects the thermal pad 81a and the thermal pad 81b. have. Such a thermal hole 80 is, for example, densely filled with a member that facilitates heat conduction, such as solder or copper plating, and is configured to facilitate heat conduction. The heat transfer member 8 is in contact with the thermal pad 81b and the heat radiating member 6, and is a member that conducts heat generated from the electronic components and conducted to the thermal pad 81 to the heat radiating member 6. It is formed of a low thermal resistance member having flexibility such as a heat conductive sheet.

  Such a circuit board 5 is provided with a drive circuit having a plurality of switching elements for supplying a PWM-controlled drive current to the motor 4, and is connected to the switching elements and supplies a control signal to the switching elements. And a control circuit is provided. The rotor 41 is rotated by the magnet 41b of the rotor 41 being attracted by the rotating magnetic field of the stator core 40a and the winding 40d generated based on such an instruction from the circuit board 5. The control circuit is a sensorless control system that does not require a rotation detection sensor. Thereby, the circuit board 5 does not need to include a rotation angle detector for detecting the rotation angle state of the output shaft 42 in the vicinity of the output shaft 42, and therefore, the notch 50 can be easily provided in the vicinity of the output shaft 42. It can be formed.

  The heat radiating member 6 is inserted into the heat radiating member fixing portion 32 of the base frame 3 and is fixed to the base frame 3. The heat radiating member 6 is disposed on the base frame 3 in the streamline of air flowing from the introduction opening 21a to the central opening 20d. As shown in FIG. 6, the heat radiating member 6 includes a first heat radiating portion 60, a second heat radiating portion 61, a flange portion 62, and a fixing portion 63. The first heat radiation part 60 is a part exposed to the outside of the casing 2 from the heat radiation member exposure opening 20e, and has a base part 60a and a plurality of ribs 60b. The base 60a is a substantially flat part. A plurality of ribs 60b are provided to protrude vertically from the base 60a.

  The second heat radiation part 61 has a base part 61a and a rib 61b. The base 61 a has a substantially rectangular parallelepiped shape, and the bottom surface is in contact with the heat transfer member 8. The rib 61b is a plate member that protrudes perpendicularly from the side surface of the base portion 61a, and is shaped into a right triangle having a hypotenuse that connects the peripheral surface of the base portion 61a and the outer edge of the flange portion 62. The flange portion 62 is provided on the boundary between the first heat radiating portion 60 and the second heat radiating portion 61. The flange portion 62 is a plate-like member in which an annular elastic member 7a shown in FIG. 4 is provided on the surface on the upper casing portion 2A side. As shown in FIG. 4, the elastic member 7 a is an annular rubber seal member provided on the flange portion 62 of the heat radiating member 6, and contacts the upper casing portion 2 </ b> A. The elastic member 7a seals a gap between the edge of the heat radiation member exposed opening 20e and the heat radiation member 6. The fixing portion 63 is formed so as to protrude from the peripheral surface portion of the second heat radiating portion 61, and has a screw hole for fixing the heat radiating member 6 to the base frame 3.

  Such a heat radiating member 6 is a member that conducts heat generated from the electronic component from the circuit board 5 and discharges it from the first heat radiating portion 60 and the second heat radiating portion 61. Further, the heat radiating member 6 has a shape in which the areas of the first heat radiating portion 60 and the second heat radiating portion 61 are smaller than the flange portion 62 in a plan view from the upper side and the lower side.

  As shown in FIG. 7, the heat radiating member 6 having the above-described shape is formed by a die casting method in which a molten metal such as aluminum is poured at high speed into a mold X in which the upper mold X1 and the lower mold X2 are combined. Is formed as a single unit. A first heat radiating portion 60 and a flange portion 62 are formed by the upper die X1, and a second heat radiating portion 61 and a fixing portion 63 are formed by the lower die X2. At this time, the upper mold X1 and the lower mold X2 are set so that the flange portion 62 and the fixing portion 63 are parting lines. Further, the upper mold X1 and the lower mold X2 are set so that a draft angle is formed in the first heat radiation part 60 and the second heat radiation part 61. For this reason, the mold X does not require an undercut process.

The flow of exhaust heat inside the blower A of this embodiment will be described.
When the motor 4 of the blower motor unit 1 is driven, the electronic component mounted on the circuit board 5 generates heat. Heat generated from the electronic component is transmitted from the thermal pad 81a to the thermal pad 81b through the thermal hole 80 filled with solder. Furthermore, the heat conducted to the thermal pad 81 b is conducted from the base portion 61 a of the heat radiating member 6 to the rib 61 b and the first heat radiating portion 60 through the heat transfer member 8.

  On the other hand, when the motor 4 is driven, the output shaft 42 is rotated with the rotor 41 and the blower fan B is rotated. When the blower fan B is rotated, an air flow is generated around the blower fan B. Here, a part of the air blown by the blower fan B into the blower motor B flows into the blower motor unit 1 from the introduction opening 21a communicated with the air flow direction downstream of the fan case C. The air introduced into the casing 2 from the introduction opening 21a passes through the gas guide 21 and branches in multiple directions. Here, a part of the air flows into the gap above the base frame 3, that is, between the base frame 3 and the upper casing portion 2A. Furthermore, a part of the air flows into the space below the base frame 3, that is, between the circuit board 5 and the lower casing portion 2B.

  The air that has flowed into the upper side of the base frame 3 comes into contact with the second heat radiating portion 61 of the heat radiating member 6 and flows along the base 61 a of the second heat radiating portion 61 toward the peripheral surface portion 20 b of the casing 2. 5 and the heat radiating member 6 are cooled. Further, the air that has cooled the heat radiating member 6 and has flowed in the direction of the peripheral surface portion 20b travels along the outer peripheral edge of the rotor 41 toward the upper side of the casing 2, passes through the central opening 20d, and is on the fan case C side. Is discharged.

  At this time, the air that flows into the gap between the circuit board 5 and the lower casing portion 2B and passes along the lower casing portion 2B below the output shaft 42 is guided in the direction of the output shaft 42 by the guide wall portion 20g. It is led to the motor side opening 33b. Part of the air flows into the gap between the peripheral surface portion 41d of the rotor 41 and the base frame 3 and the upper casing portion 2A, and is discharged from the central opening 20d. At this time, air is returned in the direction of the output shaft 42 along the guide wall portion 20g, and therefore does not stay in the lower casing portion 2B. Further, a part of the air discharged through the central opening 20d is returned to the air blown in the fan case C, and flows toward the introduction opening 21a along the upper casing portion 2A. At this time, heat from the electronic component is conducted to the first heat radiating portion 60 of the heat radiating member 6. The heat conducted to the first heat radiating portion 60 is transferred to the air by contacting with the air flowing toward the downstream side in the air blowing direction of the air in the fan case C along the upper casing portion 2A.

  According to the blower motor unit 1 according to this embodiment, the heat radiating member 6 has the first heat radiating part 60 and the second heat radiating part 61. Thereby, the heat radiating member 6 can radiate heat inside and outside the casing 2. Therefore, the cooling efficiency of the blower motor unit 1 can be improved.

  Moreover, according to the blower motor unit 1 which concerns on this embodiment, the heat-transfer member 8 is provided. Thereby, the heat generated from the electronic component mounted on the circuit board 5 can be conducted to the heat radiating member 6. Therefore, the cooling efficiency of the blower motor unit 1 can be improved also by this.

  Further, according to the blower motor unit 1 according to the present embodiment, the circuit board 5 has the thermal hole 80 formed at a position where an electronic component having a large heat generation amount is present. Thereby, it is possible to efficiently transfer heat from the surface on which the electronic components of the circuit board 5 are mounted to the opposite surface. Therefore, the cooling efficiency of the blower motor unit 1 can be improved also by this.

  Further, according to the blower motor unit 1 according to the present embodiment, the heat radiating member 6 is located in a streamline of air flowing from the introduction opening 21a to the central opening 20d. Therefore, the heat radiating member 6 can efficiently come into contact with air. Therefore, the cooling efficiency of the blower motor unit 1 can be improved also by this.

  Further, according to the blower motor unit 1 according to the present embodiment, the heat radiating member 6 includes the first heat radiating portion and the second heat radiating portion formed integrally, and further includes a flange portion. And the 2nd thermal radiation part 61 is set smaller than the flange part 62, and the shape is set. Further, the upper mold X1 and the lower mold X2 are set so that the flange portion 62 and the fixing portion 63 are parting lines. For this reason, it is not necessary to perform an undercut process at the time of the shaping | molding of the heat radiating member 6, and manufacture of the heat radiating member 6 becomes easy.

  Moreover, according to the blower motor unit 1 according to the present embodiment, the second heat radiating portion 61 has a right-angled triangular rib 61b. Thereby, the 2nd thermal radiation part 61 can enlarge the surface area which contacts air. Further, since the oblique side of the rib 61b has a draft, it can be easily taken out from the lower mold X2 during molding. Therefore, it is possible to improve the cooling efficiency of the heat radiating member 6 and facilitate the manufacture.

  Moreover, according to the blower motor unit 1 which concerns on this embodiment, the elastic member 7a is provided. For this reason, it is possible to seal between the heat radiating member 6 and the edge of the heat radiating member exposure opening 20e. Thereby, it is possible to prevent dew condensation generated outside the casing 2 from flowing into the casing 2 from the heat radiation member exposure opening 20e and adhering to the circuit board 5.

  Moreover, according to the blower motor unit 1 which concerns on this embodiment, the elastic member 7 and the elastic member 7a are provided. The elastic member 7 can absorb the vibration of the motor 4 generated on the base frame 3 by being interposed between the casing 2 and the base frame 3. Moreover, since the elastic member 7a is a flexible material, the vibration generated on the base frame 3 and transmitted to the heat radiating member 6 is inserted between the flange portion 62 of the heat radiating member 6 and the casing 2. Can be absorbed. Thereby, the vibration of the motor 4 is not transmitted to the casing 2.

In addition, this invention is not limited to the said embodiment, For example, the following modifications can be considered.
(1) In the above embodiment, the elastic member 7a is an annular rubber seal member provided on the flange portion 62 of the heat dissipation member 6, but the present invention is not limited to this. The elastic member 7a may be a rubber-based elastic adhesive that is applied to the flange portion 62 of the heat radiating member 6 and forms a flexible rubber-like elastic body after curing.

(2) In the above embodiment, the heat transfer member 8 is formed of a flexible member having a low thermal resistance such as a heat conductive sheet, but the present invention is not limited to this. The heat transfer member 8 may be heat transfer grease, and heat may be transferred from the circuit board 5 to the heat dissipation member 6 by applying grease to the opposing surface of the thermal pad 81b and the heat dissipation member 6.

(3) In the said embodiment, although the thermal radiation member 6 shall be manufactured by the die-casting method, this invention is not limited to this. The heat radiating member 6 may be a green compact made of ceramics (for example, silicon carbide SiC, aluminum nitride AlN, alumina Al ₂ O _3, etc.) molded by a mold and having high thermal conductivity.

DESCRIPTION OF SYMBOLS 1 ... Blower motor unit, 2 ... Casing, 20 ... Casing part, 3 ... Base frame, 4 ... Motor, 5 ... Circuit board, 6 ... Heat radiation member, 60 ... 1st heat radiation part, 60a ... Base, 60b ... Rib, 61 ... 2nd heat radiation part, 61a ... base part, 61b ... rib, 62 ... flange part, 63 ... fixing part, 7 ... elastic member, 7a ... elastic member, 8 ... heat transfer member, B ... blower fan

Claims (8)

A blower motor unit for air conditioning comprising a brushless motor, an electronic board that drives the brushless motor, a casing that houses the brushless motor and the electronic board, and a heat dissipation member connected to the electronic board,
The heat radiating member has a first heat radiating portion exposed to the outside of the casing, and a second heat radiating portion arranged inside the casing. A heat transfer member that conducts heat of the electronic substrate to the heat dissipation member;
The blower motor unit for air conditioning according to claim 1, wherein the heat transfer member is interposed between the electronic board and the heat dissipation member.   The air-conditioning blower motor unit according to claim 2, wherein the electronic board is formed with a thermal hole for conducting heat at a position in contact with the heat transfer member. The casing includes an introduction opening for taking outside air inside, and a discharge opening for discharging the air flowing in from the introduction opening to the outside.
The blower motor unit for air conditioning according to any one of claims 1 to 3, wherein the heat radiating member is disposed in a streamline of air flowing from the introduction opening to the discharge opening. The heat dissipating member includes the first heat dissipating part and the second heat dissipating part integrally formed, and further includes a flange part,
The blower motor unit for air conditioning according to any one of claims 1 to 4, wherein the first heat radiating portion and the second heat radiating portion are set to be smaller than the flange portion in plan view.   6. The air conditioner blower motor unit according to claim 5, wherein the second heat radiating section includes a substantially rectangular parallelepiped base and a triangular rib projecting from a side surface of the base. The casing has an opening through which the heat dissipation member is inserted;
A blower motor unit for air conditioning according to any one of claims 1 to 6, further comprising a seal portion that seals a gap between an edge of the opening and the heat dissipation member. A base frame fixed inside the casing and supporting the electronic substrate and the heat dissipation member;
The air blower motor unit for air conditioning according to claim 7, further comprising: an elastic member interposed between the base frame and the casing at a position where the base frame is fixed to the casing.

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