JP4260439B2 - Electric blower and vacuum cleaner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric blower and a vacuum cleaner.
[0002]
[Prior art]
In order to drive a brushless DC motor used for a household vacuum cleaner or the like, a drive control circuit is required. This control circuit (electronic components such as semiconductor elements) generates heat due to power loss and needs to be cooled. The cooling structure of the drive control circuit for the electric blower using the brushless DC motor is described in, for example, Japanese Patent Application Laid-Open No. 11-336696 and Japanese Patent Publication No. 7-35797.
[0003]
In the electric blower described in Japanese Patent Laid-Open No. 11-336696, an outer cylinder is provided on the outer side of a frame that holds an electric motor or the like, and a driving semiconductor element is attached to the outer cylinder. A flow path for flowing the exhaust air from the impeller is formed between the frame and the outer cylinder, and the driving circuit for driving the electric blower is cooled by using the outer cylinder as a cooling fin.
[0004]
In addition, the electric blower described in Japanese Patent Publication No. 7-35797 is provided with a heat radiating cover having a duct at the air inlet of the blower, a drive control circuit is attached to the heat radiating cover, and the air flow flowing into the blower In this configuration, the drive control circuit is cooled.
[0005]
[Problems to be solved by the invention]
The electric blower described in Japanese Patent Application Laid-Open No. 11-336696 has an outer cylinder installed as a cooling fin on the outside of the frame, leading to an increase in size and cost of the electric blower. In addition, since the outer cylinder is made of heat radiating fins, the heat radiating area is widened, but the cross-sectional area of the flow path between the frame and the outer cylinder is widened, and the flow rate of air flowing therethrough is slowed down, so the heat radiating action is reduced The cooling effect may be insufficient. If the cross-sectional area of the flow path is narrowed in order to increase the flow velocity, the ventilation resistance in the flow path increases and the efficiency of the electric blower decreases.
[0006]
Since the electric blower described in Japanese Patent Publication No. 7-35797 is provided with a heat dissipation cover having a duct, the electric blower is increased in size. Further, since the flow passage cross-sectional area on the intake side is small, the flow velocity is fast, the friction loss in the duct is increased, and the ventilation resistance is increased, so that the efficiency of the electric blower is lowered.
[0007]
One object of the present invention is to realize a cooling mechanism for cooling a driving semiconductor element that controls an electric motor in an electric blower with a relatively simple configuration and a small size.
[0008]
Another object of the present invention is to provide a relatively simple and small cooling mechanism for cooling a driving semiconductor element that controls an electric motor in an electric blower, and to suppress an increase in ventilation resistance.
[0009]
[Means for Solving the Problems]
In the present invention, the diffuser blades installed on the outer periphery of the impeller are integrally raised from the fan casing on the inner surface side of the fan casing, and are driven to the fan casing so as to be positioned on the outer surface side facing the standing position of the diffuser blades. The semiconductor element is attached in close contact , and the heat generated in the driving semiconductor element is transmitted to the diffuser blade through the fan casing, and is efficiently dissipated into the high-speed airflow flowing therethrough.
[0010]
Specifically, an electric motor part and a blower part are provided, and the blower part is provided with a diffuser in which diffuser blades are erected so as to be positioned on the outer periphery of the impeller, and a fan casing provided so as to surround the impeller and the diffuser. In the electric blower comprising
The diffuser blades are erected integrally from the inner surface side of the fan casing, and are positioned on the outer surface side of the fan casing facing the standing position of the diffuser blades, and the driving semiconductor elements are attached to the fan casing in close contact with each other . It is characterized by
A protective cover for covering the driving semiconductor element is provided,
The drive semiconductor element and the control signal generation circuit are integrated into a system power module, and the system power module is attached to the outside of the fan casing,
The electric blower is supported by the cleaner body via a vibration-proof rubber fitted to the air inlet of the blower part and a vibration-proof rubber fitted to the outer periphery of the bearing chamber at the bottom of the housing of the motor part. And
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
First Embodiment This first embodiment is a driving semiconductor element for controlling a driving current of an electric motor by raising a diffuser blade provided downstream of an impeller of an air blower section in an electric blower from an inner surface of a fan casing. By installing a certain driving semiconductor switching element on the outer surface of the fan casing, the heat generated in the driving semiconductor switching element is transmitted to the diffuser blade through the fan casing, and the flow flowing along the diffuser blade is high. It is the structure which dissipates efficiently in the airflow of a flow velocity, and cools.
[0013]
The first embodiment will be specifically described with reference to FIGS. FIG. 1 is a cross-sectional plan view of the electric blower in this embodiment. The electric blower in this embodiment is used for a vacuum cleaner, and a brushless DC motor is used as the electric motor. FIG. 2 is a front view of an impeller and a diffuser in this electric blower. FIG. 3 is a surface view of the end bracket and guide plate of the electric blower. FIG. 4 is a front view of a fan casing on which electric circuit components are mounted in the electric blower. FIG. 5 is an electric circuit diagram of a vacuum cleaner using this electric blower.
[0014]
First, the electric motor unit 100 will be described. The rotor 101 has a configuration in which permanent magnets (magnetic poles) are arranged on the outer peripheral side of the core, and is fitted to the rotating shaft 102. The stator 103 includes a drive winding 104 and is fixed in the housing 105 so as to be positioned on the outer periphery of the rotor 101. The housing 105 is a member that has been drawn into a bottomed cylindrical shape, holds the bearing 106 in a bearing chamber formed on the bottom side, and a bearing 109 on a bar-shaped end bracket 108 that is attached to the open side by a set screw 107. And the rotary shaft 102 is supported by the two bearings 106 and 109. The drive winding 104 rotates in accordance with the magnetic pole position of the rotor 101 by performing on / off control of the driving semiconductor switching element according to the relative position of the rotor 101 with respect to the magnetic pole (permanent magnet). Generate a magnetic field. The rotational position of the magnetic pole of the rotor 101 is detected by a sensor such as a Hall element mounted on the rotational position detection substrate 110. The housing 105 is provided with a plurality of exhaust windows 111 so as to be positioned on both sides of the stator 103.
[0015]
Next, the blower unit 200 will be described. A centrifugal impeller 201 attached to a rotating shaft 102 extending from the electric motor unit 100 has a plurality of impeller blades 202. A diffuser 204 provided with a plurality of diffuser blades 203 is installed on the outer peripheral side of the impeller 201. A guide plate 206 provided with a plurality of guide vanes 205 is installed on the back side of the impeller 201 so as to be fixed to the end bracket 108. The guide vanes 205 of the guide plate 206 are formed in a substantially streamline shape.
[0016]
The fan casing 207 is made of a metal member having excellent thermal conductivity, and is provided with an air inlet 208 at the center, and the diffuser blade 203 is integrally raised on the inner side (inner surface side). The diffuser 204 is fitted to the open side end of the housing 105 of the electric motor unit 100 so as to contain the diffuser 204. The driving semiconductor switching element 401 is fixed to the fan casing 207 in close contact with the fan casing 207 so as to be located on the outer side (outside view) facing the standing position of the diffuser blade 203 in the fan casing 207. The control circuit boards 402 and 403 for controlling the on / off of the driving semiconductor switching element 401 are formed in an annular shape so as to avoid the suction port 208, and are controlled by a plurality of board support pins 209 and a board spacer 210 erected on the fan casing 207. It is supported on a step and fixed with screws 211. In addition, illustration description of electrical circuit components, such as IC and a resistor mounted in the control circuit boards 402 and 403, is abbreviate | omitted here. The driving semiconductor switching element 401 and the control circuit boards 402 and 403, the drive winding 104, the rotational position detection board 110, and the wiring 404 connected to the external electric circuit of the electric blower are along the outer peripheral surfaces of the fan casing 207 and the housing 105. Arrange.
[0017]
The drive semiconductor switching element 401 and the control circuit boards 402 and 403 are assembled to the fan casing 207 as follows.
[0018]
First, the driving semiconductor switching element 401 is fixed to the fan casing 207 with a set screw 405. The fan casing 207 and the diffuser blade 203 standing up inside the fan casing 207 function as a radiator that receives heat from the driving semiconductor switching element 401 and dissipates heat to a high-speed air current blown out from the impeller 201. Therefore, it is desirable to reduce the heat transfer resistance between the drive semiconductor switching element 401 and the fan casing 207 by interposing a heat conductive grease or a heat conductive sheet. Next, the control circuit board 402 is fitted to the three board support pins 209 and soldered to the terminals of the driving semiconductor switching element 401. A control circuit board 403 is fitted thereon with a board spacer 210 interposed, and is fastened and fixed with screws 211.
[0019]
Next, an electrical circuit when this electric blower is used in a vacuum cleaner will be described.
[0020]
The drive winding 104 in the motor unit 100 has a three-phase star connection, and is connected to a DC drive power source (battery) 406 via a drive semiconductor switching element 401 connected in a three-phase inverter. The driving semiconductor switching element 401 is preferably a semiconductor switching element that can be turned on and off by a control signal, such as various power transistors and a gate turn-off switch. In the case of using a commercial AC power supply, a DC drive power supply is obtained by adding a rectifier circuit and a smoothing circuit.
[0021]
A control signal generation circuit 407 that controls on / off of the driving semiconductor switching element 401 is mounted on the control circuit boards 402 and 403, and power is supplied (excitation) in accordance with the rotation position detection signal from the sensor 112 mounted on the rotation position detection board 110. A control signal for controlling on / off of the driving semiconductor switching element 401 connected to the drive winding 104 to be controlled is generated. The control signal generation circuit 407 is connected to the main control circuit 408 mounted on the vacuum cleaner main body, and controls the motor unit 100 in accordance with operation signals from the operation switch 409 such as operation / stop and speed control. Execute the process.
[0022]
In the electric blower configured as described above, when an operation signal for operation and speed instruction is generated from the operation switch 409, the main control circuit 408 causes the control signal generation circuit 407 to rotate the rotor 101 of the motor unit 100 at the instruction speed. To instruct.
[0023]
Upon receipt of this instruction, the control signal generation circuit 407 detects the position of the magnetic pole of the rotor 101 with reference to the rotation position detection signal from the sensor 112, and applies it to the drive winding 104 that generates rotation torque in the rotor 101. The driving semiconductor switching element 401 is controlled to be turned on and off so as to supply power. In addition, the control signal generation circuit 407 obtains the rotational speed of the rotor 101 by arithmetic processing based on the rotational position detection signal, and performs power feeding control so as to be the indicated speed.
[0024]
Airflow generated when the impeller 201 attached to the rotating shaft 102 rotates at high speed as the rotor 101 rotates is sucked from the intake port 208, blown to the outer periphery of the impeller 201, and decelerated by the diffuser blade 203 of the diffuser 204. To recover pressure. The airflow emitted from the diffuser 204 is folded around the outer periphery of the guide plate 206 and passes between the guide blades 205 standing up from the guide plate 206 and flows into the housing 105 of the electric motor unit 100. A part of the airflow that has flowed into the housing 105 is exhausted from the exhaust window 111 while cooling the stator 103 and the drive winding 104 on the upstream side of the stator 103, and the rest is the stator 103. , The stator 103 and the drive winding 104 are cooled and exhausted from the exhaust window 111 to the outside of the machine.
[0025]
The heat generated in the driving semiconductor switching element 401 in accordance with the power feeding control to the drive winding 104 of the electric motor unit 100 is transmitted to the fan casing 207 and further transmitted from the fan casing 207 to the diffuser blade 203 that stands integrally therewith. . And it diffuses in the airflow from these surfaces. Since the high-speed airflow blown from the outer periphery of the impeller 201 flows through the diffuser 204, the diffuser blades 203 also function as heat radiating fins and are generated in the driving semiconductor switching element 401 to efficiently dissipate heat into the airflow. can do.
[0026]
In this way, by using the diffuser blade 203, which is a constituent element of the blower unit 200, as a heat radiating fin, a separate heat radiating fin for cooling the driving semiconductor switching element 401 becomes unnecessary, so that the air flow is reduced. There is no hindrance, and there is no increase in friction loss against the airflow. Therefore, the cooling mechanism can be configured simply and compactly, and an increase in ventilation resistance can be suppressed.
[0027]
In order to efficiently transmit the heat generated by the driving semiconductor switching element 401 to the diffuser blade 203 to dissipate the heat, the fan casing 207 is drawn from a metal plate material having excellent heat conductivity, or a metal having excellent heat conductivity. It is preferable that the members are forged and the diffuser blades 203 made in the same manner are joined together by brazing, welding, or the like, or formed integrally by aluminum die casting.
[0028]
Further, since the control circuit boards 402 and 403 are provided in the vicinity of the driving semiconductor switching element 401, the wiring connecting the two is shortened, so that the electrical loss is reduced and the wiring weight is reduced. Further, a power supply line that connects the driving semiconductor switching element 401 and the control circuit boards 402 and 403 to the power source 406, a power supply line that connects the driving semiconductor switching element 401 and the drive winding 104, and a signal line that transmits the rotational position detection signal are fans. By passing the outside of the casing 207, the wiring 404 for power supply and signals does not cross the ventilation path, and it does not cause airflow resistance or turbulence. can do.
[0029]
Second Embodiment In the second embodiment, the outer periphery of the driving semiconductor switching element and the control circuit board in the first embodiment is surrounded and protected by a protective cover, and the blower is provided by the protective cover. It is the structure which formed the inlet port with the sufficient intake efficiency of a part.
[0030]
The second embodiment will be specifically described with reference to FIG. FIG. 6 is a cross-sectional plan view of the electric blower in this embodiment. Note that the same or corresponding components as those in the first embodiment described above are denoted by the same reference numerals, and redundant description is omitted.
[0031]
In this embodiment, the opening corresponding to the air inlet of the fan casing 207 is formed in an open state where it is raised in a cylindrical shape toward the front, and the driving semiconductor switching element 401 and the control circuit board 402 are formed outside thereof. , 403, a protective cover 212 is fitted to the fan casing 207, and an intake port 213 formed with a large curvature at the center of the protective cover 212 is opposed to the impeller 201. The protective cover 212 is a control means accommodating space 214 that accommodates the driving semiconductor switching element 401 and the control circuit boards 402 and 403 in an airtight state in contact with the outer periphery of the fan casing 207 and the tip of the opening portion standing in a cylindrical shape. The intake and exhaust of the impeller 201 do not touch the driving semiconductor switching element 401 and the control circuit boards 402 and 403.
[0032]
In the electric blower configured as described above, the airflow generated when the impeller 201 rotates at high speed is sucked into the impeller 201 from the intake port 213 formed in the protective cover 212, but the intake port 213 having a large curvature is uniform. Since the impeller 201 can be sucked by the flow, the blowing efficiency can be improved. Further, since the intake and exhaust air of the impeller 201 does not flow through the control means accommodation space 214, even if the dust collection bag of the vacuum cleaner is broken and dust is mixed into the airflow, the dust is driven by the driving semiconductor switching element 401. In addition, it is possible to prevent electrical troubles from adhering to the control circuit boards 402 and 403.
[0033]
In this embodiment, the suction port 213 is provided in the protective cover 212. However, similarly to the first embodiment, the fan casing 207 is provided with a suction port, and the protective cover 212 is provided with the driving semiconductor switching element 401 and the control cover 212. It can be modified to a configuration limited to the protection function of the circuit boards 402 and 403.
[0034]
Third Embodiment In the third embodiment, the driving semiconductor switching element and the control circuit board in the first embodiment described above are integrated into a system power module, and this system power module is used as a fan casing. It is the structure attached to. Accordingly, in this embodiment, there is no occurrence of electrical trouble due to dust adhesion, and the assembly work of the electric blower is further facilitated.
[0035]
The third embodiment will be specifically described with reference to FIG. FIG. 7 is a cross-sectional plan view of the electric blower in this embodiment. Note that the same or corresponding components as those in the first embodiment described above are denoted by the same reference numerals, and redundant description is omitted.
[0036]
The system power module 410 in this embodiment is an annular body in which a driving semiconductor switching element 401 and control circuit boards 402 and 403 (control signal generating circuit 407) for controlling on / off thereof are integrated. The system power module 410 protects the lead portion of the wiring 404 by molding it using an insulating material such as silicon rubber. The system power module 410 is fixed in close contact with the fan casing 207 so as to be positioned on the front side of the standing position of the diffuser blade 203 in the fan casing 207. In order to reduce the heat transfer resistance between the system power module 410 and the fan casing 207, it is preferable to interpose a heat conductive grease or a heat conductive sheet between them.
[0037]
In the electric blower in this embodiment, the driving semiconductor switching element 401 and the control signal generation circuit 407 are integrated as the system power module 410, so that the electric circuit means is further reduced in size and the attachment work to the fan casing 207 is easy. It becomes. The heat generated by the driving semiconductor switching element 401 and the control signal generation circuit 407 is dissipated to the surrounding atmosphere and is efficiently dissipated to the high-speed airflow that is transmitted to the fan casing 207 and the diffuser blades 203 and blows out from the impeller 201. In addition, since the driving semiconductor switching element 401 and the control signal generation circuit 407 for controlling on / off of the driving semiconductor switching element 401 are integrated in the system power module 410 and the connection portion with the external wiring 404 is molded with an insulating material. Further, it is possible to prevent electrical troubles due to dust adhesion.
[0038]
Fourth Embodiment The fourth embodiment is an electric vacuum cleaner that is rationally mounted on the main body of the vacuum cleaner by deforming the air inlet of the fan casing in the electric blower of the first embodiment described above. is there.
[0039]
The fourth embodiment will be specifically described with reference to FIG. FIG. 8 is a cross-sectional plan view of a portion of the electric blower in the electric vacuum cleaner of this embodiment. Since the overall configuration of the vacuum cleaner is the same as that of a conventional vacuum cleaner, only the electric blower portion is illustrated and described here. Note that the same or corresponding components as those in the first embodiment described above are denoted by the same reference numerals, and redundant description is omitted.
[0040]
The vacuum cleaner main body 500 includes electric blower support plates 501 and 502, and the support plate 501 forms an inlet 503 for the blower unit 100. On the upstream side of the support plate 501, a partition plate 504 that partitions the dust collection chamber portion of the cleaner main body 500 and the electric blower portion is provided, and a ventilation window 505 to the electric blower portion is provided at a substantially central portion of the partition plate 504. A grid-like guard 506 is attached to the ventilation window 505.
[0041]
The air inlet 208 of the fan casing 207 of the blower unit 200 is formed so as to protrude in a cylindrical shape, and is supported by the support plate 501 with a vibration isolating rubber 507 interposed between the support plate 501 and the support plate 501. The vibration isolating rubber 507 and the intake port 208 form a large curvature ventilation path (intake port). Further, a vibration isolating rubber 508 is fitted on the outer periphery of the bearing chamber at the bottom of the housing 105 of the motor unit 100 and is supported by the support plate 502.
[0042]
As described above, the configuration in which the electric blower supports the suction port 208 of the fan casing 207 and the bearing chamber of the housing 105 on the vacuum cleaner main body 500 via the vibration isolating rubbers 507 and 508 is based on the vibration caused by the high-speed rotation of the electric blower. It is difficult to be transmitted to the main body 500, which is suitable for realizing low vibration and low noise.
[0043]
Further, the anti-vibration rubber 507 also functions as a seal that prevents airflow between the air inlet 208 of the fan casing 207 and the support plate 501, so that ventilation around the driving semiconductor switching element 401 and the control circuit boards 402 and 403 is performed. Since it reduces, it can suppress that an electrical trouble generate | occur | produces by dust adhesion.
[0044]
In the electric vacuum cleaner configured as described above, when the electric blower is operated, the air in the dust collecting chamber flows into the impeller 201 from the ventilation window 505 through the suction port 503 and the suction port 208, and on the outer periphery of the impeller 201. The air is blown out, decelerated by the diffuser blades 203 and the guide blades 205, and flows into the housing 105. The stator 103 and the drive winding 104 are cooled and exhausted from the exhaust window 111 to the outside of the machine.
[0045]
Since such an air flow is blown out from the impeller 201 at a high flow velocity and collides with the diffuser blade 203, heat is efficiently taken from the diffuser blade 203, so that the heat generated in the driving semiconductor switching element 401 is transferred to the fan casing 207. Can be efficiently dissipated through
[0046]
In each of the above-described embodiments, the position detection board 110 on which a sensor is mounted is provided to detect the rotational position of the magnetic pole of the rotor 101 in the electric motor unit 100, but based on the current flowing through the drive winding 104. It can deform | transform into the structure to detect.
[0047]
Moreover, it can also implement in the form which changed and changed suitably the component in each embodiment mentioned above.
[0048]
【The invention's effect】
According to the present invention, the diffuser blades are integrally raised from the inner surface side of the fan casing, and the driving semiconductor element is attached to the fan casing in close contact with the diffuser blades on the outer surface side of the fan casing facing the standing position of the diffuser blades. Compared with the cooling mechanism that cools the drive semiconductor element that controls the motor in the electric blower by using the diffuser blades raised in the fan casing as a radiator to cool the drive semiconductor element efficiently Therefore, it is possible to reduce the increase in ventilation resistance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional plan view of an electric blower according to a first embodiment of the present invention.
2 is a front view of an impeller and a diffuser in the electric blower shown in FIG. 1. FIG.
3 is a surface view of an end bracket and a guide plate of the electric blower shown in FIG. 1. FIG.
4 is a front view of a fan casing on which an electric circuit component is mounted in the electric blower shown in FIG. 1. FIG.
FIG. 5 is an electric circuit diagram of a vacuum cleaner using the electric blower shown in FIG. 1;
FIG. 6 is a cross-sectional plan view of an electric blower according to a second embodiment of the present invention.
FIG. 7 is a cross-sectional plan view of an electric blower according to a third embodiment of the present invention.
FIG. 8 is a cross-sectional plan view of a portion of an electric blower of a vacuum cleaner according to a fourth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Electric motor part, 200 ... Blower part, 201 ... Impeller, 203 ... Diffuser blade, 204 ... Diffuser, 207 ... Fan casing, 212 ... Protective cover, 401 ... Semiconductor switching element for drive, 402, 403 ... Control circuit board, 410 ... System power module, 500 ... Vacuum cleaner main body, 507, 508 ... Anti-vibration rubber.

Claims (5)

In the electric blower, the electric blower unit includes an electric motor part and a blower part, and the blower part includes a diffuser in which a diffuser blade is erected so as to be positioned on an outer periphery of the impeller, and a fan casing provided so as to surround the impeller and the diffuser. ,
The diffuser blade is erected integrally from the inner surface side of the fan casing, and is located on the outer surface side of the fan casing opposite to the position where the diffuser blade is raised , and the driving semiconductor element is attached to the fan casing in close contact with the fan casing . An electric blower characterized by that.   The electric blower according to claim 1, further comprising a protective cover that covers the driving semiconductor element.   3. The electric blower according to claim 2, wherein the driving semiconductor element and the control signal generating circuit are integrated to form a system power module, and the system power module is attached to the outside of the fan casing.   An electric vacuum cleaner comprising the electric blower according to claim 1.   5. The electric blower according to claim 4, wherein the electric blower is supported by the cleaner body through an anti-vibration rubber fitted to the air inlet of the blower unit and an anti-vibration rubber fitted to the outer periphery of the bearing chamber at the bottom of the housing of the electric motor unit. A vacuum cleaner characterized by having been made.

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