JP2007032281A - Electric blower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize and improve efficiency of an electric blower equipped with a DC motor having a drive circuit board built therein. <P>SOLUTION: In the electric blower 1 provided with a brushless DC motor 50, a motor case 3a supporting a stator outer circumference part of the brushless DC motor 50, the drive circuit board 5 provided inside of the motor case 3a and provided with a control element 23 controlling electric power of the brushless DC motor 50, and a fan rotated by the brushless DC motor 50, and discharging air sucked by the fan from a discharge port formed on the motor case, a wind passage window 30 making air pass from the fan to the discharge port is provided in the drive circuit board 5, lead wire connecting a power control element 23 and a drive power source part 23 of the brushless DC motor 50 mounted on the drive circuit board 5 is provided and a prevention means preventing the lead wire from sticking out to the wind passage window 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric blower incorporating a drive circuit board.

As a conventional electric blower, for example, in Patent Document 1, a drive circuit board is built in a motor bracket in order to achieve miniaturization and compactness and to efficiently cool a heating element of a circuit unit. Is disclosed.
JP 2002-78649 A

  Since the electric blower generally has a large driving power, the value of the current flowing through the power control element is large, and if this wiring is formed on the circuit board, it is necessary to take measures such as widening the wiring pattern. Therefore, a predetermined wiring pattern area is required, and the drive circuit board cannot be reduced in size. Therefore, when the drive circuit board is built in the bracket as in Patent Document 1, there is still room for further improvement in terms of downsizing the electric blower.

  An object of the present invention is to realize downsizing of an electric blower using a brushless DC motor and to suppress a reduction in blowing efficiency associated therewith.

A brushless DC motor, a motor case for supporting the outer periphery of the stator of the brushless DC motor, and a drive circuit board provided inside the motor case and provided with a control element for controlling the power of the brushless DC motor; An electric blower that includes a fan that is rotated by the brushless DC motor and that discharges air sucked by the fan from an exhaust port formed in the motor case.
The drive circuit board is provided with an air passage window through which air from the fan to the exhaust port passes, and lead wiring for connecting the drive power supply unit of the brushless DC motor mounted on the drive circuit board and the power control element is provided. And a preventive means for preventing the lead wiring from protruding into the air passage window.

  ADVANTAGE OF THE INVENTION According to this invention, the electric blower which can implement | achieve size reduction and can suppress the fall of the ventilation efficiency accompanying it can be provided.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an electric blower 1 according to an embodiment of the present invention. The electric blower 1 has a structure in which a motor case 3 a that holds a motor unit 3 including a fan unit 4 and a brushless DC motor 50 (hereinafter referred to as “motor 50”) is integrally held by a frame 2. In FIG. 1, an arrow F indicates an air path through which air sucked from the fan unit 4 is discharged to the motor unit 3.

  As shown in FIG. 5, a bearing (bearing 12) is housed in the center of the frame 2 on the inner peripheral side of the projecting portion 2 d that protrudes in a cylindrical shape, and the motor shaft 6 is rotatably held by the bearing 12. ing. Further, the upper end portion of the motor case 3a is fitted to the inner peripheral surface of the rib 2c protruding from the lower portion of the bowl-shaped outer peripheral portion 2b, and the motor case 3a is integrally held.

  A rectifying plate 7 constituting the fan portion 4 is attached to the convex portion 2 d at the center of the frame 2. A centrifugal fan 8 is attached to the motor shaft 6 on the rectifying plate 7, and a fan cover 4a is fitted and held on the outer peripheral side of the frame 2 so as to cover them. By the rotation of the centrifugal fan 8 by the operation of the motor 50, air is sucked from the suction opening 9 provided at the top of the fan cover 4a, and the air is discharged from the discharge port 10 of the centrifugal fan 8 to the side. The discharged air is guided in the direction of the motor shaft 6 by the guide member 7a of the rectifying plate 7, and is then disposed below the fan unit 4 via the vent 2a provided in the frame 2. It is sent out in the direction of the motor unit 3.

  The motor case 3a has a bottomed cylindrical shape, and a bearing (bearing 12) for rotatably holding the motor shaft 6 is housed in the bottom portion 3b, and the lower end side of the rotating shaft 6 is pivotally supported by the bearing 12. Has been. An upper portion of the motor case 3a is opened, and air sucked from the fan portion 4 is discharged into the opening. Further, an exhaust port (not shown) as a blower outlet is provided on the peripheral surface near the bottom of the motor case 3a.

  An outer peripheral portion of a stator 14 (stator) around which a stator winding 15 (see FIG. 6) constituting the motor unit 3 is wound is supported and accommodated on the inner periphery of the motor case 3a. The stator 14 has a stator winding 15 wound around a member in which a plurality of silicon steel plates are laminated.

  The rotor 13 is held by the motor shaft 6 so that the outer peripheral surface thereof faces the inner peripheral surface of the stator 14 via a predetermined gap. The rotor 13 is an internal magnet embedded type in which a plurality of silicon steel plates are laminated and a plurality of permanent magnets are divided and embedded.

  Next, FIG. 6 shows a drive circuit 20 mainly composed of an inverter circuit that controls electric power applied to the motor 50 used in the embodiment of the present invention. The direct current supplied from the direct current power supply unit 21 is converted into alternating current by the drive circuit 20. This AC current is applied to the motor 50 to perform power control. The drive circuit 20 drives an electric blower control unit 22 that controls driving of the electric blower 1, power control elements 23 a to 23 f that switch a DC current supplied from the DC power supply unit 21, and drives these power control elements 23. It comprises drive circuits 24a-24f to be controlled.

  The DC power supply unit 21 is a secondary battery such as a nickel metal hydride battery or a lithium ion battery, or an assembled battery in which a plurality of these secondary batteries are combined. In addition, the commercial power supply may be rectified and smoothed. A direct current is supplied from the direct current power supply unit 21 to the drive circuit 20. The drive circuit 20 has a configuration in which six power control elements 23a to 23f are connected in a three-phase bridge. These power control elements 23a-23f operate | move based on the pulse signal output from the electric blower control part 22 mainly having a microcomputer. The high-voltage drive circuits 24 a to 24 c and the low-voltage drive circuits 24 d to 24 f are driven by the pulse signal, and an alternating current is supplied to the stator winding 15 of the motor 50. Here, the wiring connected to the power control elements 23a to 23c from the positive terminal of the DC power supply is called the high-voltage side power supply wiring 32, and the wiring connected to the power control elements 23d to 23f from the negative terminal of the DC power supply. This is referred to as the low-voltage side power supply wiring 33.

  The electric blower control unit 22 includes an operation unit 26 for selecting start, stop, or input power of the electric blower 1, current detection means 27 for detecting a current flowing in the drive circuit 20, and an input voltage by the DC power supply unit 21. The input voltage detecting means 28 for checking is connected. Further, the electric blower control unit 22 receives magnetic pole detection information of the rotor 13 detected by a hall element or the like.

  The stator winding 15 is connected at the beginning or end of winding as a middle point 90, and the other winding end of each phase is connected to six power control elements 23a to 23f connected in a three-phase bridge. Is done.

  7 and 8 show the drive circuit board 5 on which the drive circuit 20 described above is mounted. 7 is a view of the front surface 5a of the drive circuit board 5 from the fan unit 4 side, and FIG. 8 is a view of the back surface 5b of the drive circuit board 5 from the motor 50 side.

  An air passage window 30 serving as an air passage from the fan unit 4 to the motor unit 3 is formed at the center of the donut-shaped drive circuit board 5. The ear portion 31 is provided with connection terminals 32a and 33a for connecting the high-voltage side power source wiring 32 and the low-voltage side power source wiring 33 of the DC power source unit 21. The ear portions 31 protrude from the outer peripheral portion of the drive circuit board 5 and are provided at two positions facing each other. One ear 31a is provided with a connection terminal 32a for connecting a power supply wiring 32 on the high voltage side of the power supply. In addition, a connection terminal 33a for connecting the power supply wiring 33 on the low voltage side of the power supply is disposed on the other ear portion 31b.

  In the peripheral portion of the drive circuit board 5, for example, power control elements 23a to 23f such as MOSFETs are arranged at a predetermined pitch as shown in FIG. The power control elements 23a to 23c and the connection terminal 32a are connected by the lead wiring L to form the high-voltage power supply wiring 32. Further, the power control elements 23d to 23f and the connection terminal 33a are connected by the lead wiring L to form the power supply wiring 33 on the low voltage side.

  Since the drive circuit 20 of the motor 50 has a large number of power control elements 23, if it is composed of a plurality of circuit boards, the number of connection locations becomes large, resulting in an increase in the number of assembly steps. Further, when the number of connection points increases, the reliability of the drive circuit board 5 is also affected. Therefore, the above-described problems can be solved by forming the drive circuit board with a single board as in the present invention.

  In the electric blower having the above-described configuration, when the motor 50 is driven, the fan 8 fixed to the rotating shaft 6 rotates to suck air from the suction opening 9. Then, the sucked air is discharged from the outer periphery of the fan 8 through an air outlet formed in the motor case 3 a through the rectifying plate 7, the ventilation opening 2 a of the frame 2, and the air passage window 30 of the drive circuit board 5. When the sucked air passes through the motor case 3a, the motor 50 and the drive circuit board 5 can be cooled.

  By the way, in the case of the electric blower 1 used for a vacuum cleaner, since the drive current is large, it is generally necessary to increase the wiring pattern width of the power supply unit. As a result, the pattern formation area increases, which may cause problems when the drive circuit board 5 is downsized. In particular, in the case where the drive circuit board is disposed inside the motor case, the result is an increase in the size of the entire electric blower. However, according to the configuration of the present invention, the high-voltage side and low-voltage side wirings 32 and 33 of the DC power supply unit 21 are formed by the lead wiring L, so the upper part of the wiring pattern unit (not shown) such as the control circuit unit, It is not necessary to provide the wiring pattern of the DC power supply unit 21 such that it can be three-dimensionally arranged.

  In addition, in the present invention, as will be described later, lead wire protrusion preventing means for preventing the lead wiring L from protruding into the air passage window is provided. For this reason, the trouble when the lead wire L protrudes to the air passage window 30 side, that is, the air passage resistance of the air passage from the fan to the exhaust port is increased to reduce the suction efficiency, or the lead wire L is It is possible to prevent a crack or the like from being generated in the connection portion or the like due to the external force of the air flowing through the road.

  As shown in FIG. 1, a holding member 35 is provided so that a screw protrudes from the lower portion of the drive circuit board 5 as means for preventing the lead wire from protruding into the air passage window 30 of the present invention. Thus, by arranging the holding members 35, 35 between the air passage window 30 and the lead wire L, the lead wire L can be prevented from protruding into the air passage window 30. In addition, since the holding member 35 for fixing the drive circuit board 5 to the frame 2 is used without separately providing a configuration for preventing the lead wire L from protruding into the air passage window, the drive circuit board 5 The structure can be simplified.

  Next, another embodiment for preventing the lead wiring from protruding to the air passage side will be described with reference to FIGS. As shown in FIG. 9, a cylindrical member 40 that is insertable into the air passage window 30 of the drive circuit board 5 on the lower side of the frame 2 and on the center side of the ventilation opening 2 a is attached. The cylindrical member 40 has a function of guiding the air sucked by the fan 8 to the air passage window 30, but the shape thereof is preferably a cylindrical shape when the air passage window 30 is circular, depending on the shape of the air passage window 30. Selected by design. The cylindrical member 40 is provided with a ventilation port 40 a on the cylindrical side wall, and the wind discharged from the ventilation port 2 a of the frame 2 is guided to the ventilation path window 30 of the drive circuit board 5. The tubular member 40 is inserted into the air passage window 30 of the drive circuit board 5, and the tubular member 40 is disposed between the air passage window 30 and the lead wiring L. Further, the outer peripheral end of the drive circuit board 5 is inserted and fixed in a cut groove provided in a part of the inner wall of the motor case 3a.

  By attaching the drive circuit board 5 in this manner, the lead wiring L is arranged outside the cylindrical member 40 as described above, so that it does not protrude into the air passage and can increase the air passage resistance. Absent.

  According to this embodiment, the tubular member 40 can have a function of guiding the air sucked by the fan 8 to the air passage window 30 and a function of preventing the lead wiring L from protruding into the air passage window. Therefore, it is possible to suppress a reduction in suction efficiency with a simple configuration.

  In addition, although the above-mentioned cylinder member 40 was illustrated about the case where it fixes to the lower part side of the flame | frame 2, you may make it fix directly to the air-path window 30 of the drive circuit board | substrate 5, for example.

  Moreover, in said embodiment, although illustrated about the case where the fan part 4 and the motor part 3 which comprise the electric blower 1 are hold | maintained integrally with the flame | frame 2, for example, the upper end part of the motor case 3a and the fan part 4 The fan cover 4 a may be fitted, and the bearing portion 12 may be provided at the center of the fan portion 4 to hold the motor shaft 6.

It is a front view of the electric blower of the present invention. The centrifugal fan which comprises the fan part of this invention is shown. The baffle plate which comprises the fan part of this invention is shown. It is a top view of the flame | frame of this invention. It is sectional drawing of the flame | frame of this invention. It is a circuit diagram which drives and controls the electric blower of this invention. It is a top view of the drive circuit board which drives and controls the electric blower of the present invention. It is a reverse view of the drive circuit board which drives and controls the electric blower of this invention. It is a front view which shows other embodiment of the electric blower of this invention. It is a perspective view of the flame | frame with which the cylinder member was mounted | worn.

Explanation of symbols

1 Electric blower
2 Frame 3 Motor unit 5 Drive circuit board 7 Rectifier plate 8 Centrifugal fan 9 Suction opening 11 Ventilation port 13 Rotor 14 Stator 52 Stator winding 20 Drive circuit 23 Power control element 24 Drive circuit 25 Stator winding 30 Wind Road window 32 High-voltage power supply wiring 33 Low-voltage power supply wiring 35 Holding member

Claims (3)

A brushless DC motor, a motor case for supporting the outer periphery of the stator of the brushless DC motor, and a drive circuit board provided inside the motor case and provided with a control element for controlling the power of the brushless DC motor; An electric blower that includes a fan that is rotated by the brushless DC motor and that discharges air sucked by the fan from an exhaust port formed in the motor case.
The drive circuit board is provided with an air passage window through which air from the fan to the exhaust port passes, and lead wiring for connecting the drive power supply unit of the brushless DC motor mounted on the drive circuit board and the power control element is provided. An electric blower characterized in that it is provided with prevention means for preventing the lead wiring from protruding into the air passage window.   A frame for holding a bearing that rotatably supports a rotating shaft of the brushless DC motor is provided in the motor case, the drive circuit board is fixed to the frame by a holding member, and the holding member is fixed to the air passage window and the lead. The electric blower according to claim 1, wherein the electric blower is disposed between the wiring and is used as a prevention means for preventing the air from protruding into the air passage window.   A cylindrical member that guides at least a part of the air discharged from the fan to the air path window of the drive circuit board is disposed, and the lead wiring is positioned outside the cylindrical member to position the cylindrical member. 2. The electric blower according to claim 1, wherein the blower is a preventing means for preventing the air passage window from protruding.

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