US20140056738A1

US20140056738A1 - Rechargeable fan device

Info

Publication number: US20140056738A1
Application number: US13/965,470
Authority: US
Inventors: Makoto Takahashi
Original assignee: Makita Corp
Current assignee: Makita Corp
Priority date: 2012-08-24
Filing date: 2013-08-13
Publication date: 2014-02-27
Also published as: CN103629125A; JP5959993B2; JP2014045538A; CN103629125B

Abstract

Provided is a rechargeable fan device that includes a fan; a motor that drives the fan to rotate; a battery that supplies power to the motor; a voltage generation unit that generates a control voltage of a predetermined voltage value based on DC power inputted; a first supply path used to supply DC power from the battery to the voltage generation unit; a semiconductor switch that brings the first supply path into/out of conduction; a DC jack used to input DC power from an external DC power source; a second supply path used, when the DC power is inputted into the DC jack, to supply the DC power to the voltage generation unit; and a control unit that controls driving of the motor and charging of the battery.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Patent Application No. 2012-185207 filed Aug. 24, 2012 in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

BACKGROUND

The present invention relates to a rechargeable fan device that suctions or discharges gas by driving a fan to rotate by battery power.
As a rechargeable fan device operated by battery power, a dust collection device that collects dust by suctioning outside air, an air discharging device that discharges gas, and the like are known. As a dust collection device among these, a vacuum cleaner (cleaner), an air cleaner, and the like are generally known. As an air discharging device, a blower that discharges high-pressure air of, for example, 10 kPA or more, an air discharging fan that discharges air of lower pressure than in the blower, and the like are known.
These rechargeable fan devices have a repeatedly rechargeable battery mounted therein, and are configured such that a motor is driven by the battery power and that a fan is driven to rotate by a driving force of the motor. Generally, driving of the motor is controlled by a control circuit such as a microcomputer and a control IC. Furthermore, it is general that a battery is housed within a battery pack and that the battery pack is configured to be attachable and detachable to and from a case of a device body.
Various ways of attaching and detaching a battery pack are known in a rechargeable fan device. Known, for example, are a configuration in which a battery pack is inserted into a case of a device body from an opening of the case of the device body and the opening is closed with a cover; and a configuration in which a battery pack can be directly attached and detached to and from a side surface of a case of a device body (see Japanese Unexamined Patent Application Publication No, 2010-178773, for example).

SUMMARY

However, the rechargeable fan device as described above has a problem that a charging operation of the battery is troublesome because, every time the battery is to be charged, it is necessary to detach the battery pack from the case of the device body and, after completion of the charging, to attach the battery pack to the case of the device body again.
Besides that, since the rechargeable fan device is configured to be operated by the battery power, it is desired to enable the battery to last as long as possible by reducing unnecessary power consumption even while the fan is not operating, let alone while the fan is operating.
In an aspect of the present invention, it is desirable to provide a rechargeable fan device that enables easy charging of a battery and enables the battery to last longer even in a state where the battery is attached to a device body.
A description will be given below about a rechargeable fan device of an aspect of the present invention.
The rechargeable fan device includes a fan that suctions or discharges gas; a motor that drives the fan to rotate; a battery that supplies power to the motor; and a voltage generation unit that generates a control voltage of a predetermined voltage value based on DC power inputted.
Moreover, the rechargeable fan device includes, as a supplier of DC power to the voltage generation unit, a first supply path used to supply DC power (i.e., battery power) from the battery to the voltage generation unit; a DC jack used to input DC power from an external DC power source; and a second supply path used, when DC power is inputted into the DC jack, to supply the DC power (i.e., external power) to the voltage generation unit. The rechargeable fan device further includes a semiconductor switch that brings the first supply path into/out of conduction.
Furthermore, the rechargeable fan device includes a control unit that is operated using, as a power source, the control voltage generated by the voltage generation unit. The control unit is configured: to control driving of the motor by controlling power supply from the battery to the motor; to control charging of the battery by DC power if predetermined charging execution conditions are satisfied when the DC power is inputted into the DC jack; and to shut off power supply from the battery to the voltage generation unit by turning off the semiconductor switch if predetermined shutdown conditions are satisfied during operation of the control unit itself.
In the rechargeable fan device of the present invention configured as such, if the shutdown conditions are satisfied, supply of battery power to the control unit (directly speaking, control voltage input from the voltage generation unit) is shut off by turning off the semiconductor switch. On the other hand, if DC power is inputted through the DC jack when there is no control voltage input into the control unit and the control unit is in an operation stoppage state, the control voltage is generated by the DC power and the control unit starts operating. At this time, the control unit executes charging of the battery if the charging execution conditions are satisfied.
Consequently, according to the rechargeable fan device of the present invention, a conventional operation such as detachment of the battery from a device body for charging of the battery is unnecessary, and the battery can be charged just by inputting DC power from an external power source into the DC jack. In addition, when the shutdown conditions are satisfied, power supply is stopped and the control unit no longer consumes any power. Therefore, the charging of the battery can be performed easily, and even when the battery is kept in an attached state to the device body, the battery can be made to last longer.
It is preferable that the rechargeable fan device of the present invention is further configured such that the control unit can be activated also by a user's operation. Specifically, the rechargeable fan device includes an operation switch to be operated by a user in order to drive the fan to rotate; and a switch-on unit. The switch-on unit is designed to supply DC power from the battery to the voltage generation unit by turning on the semiconductor switch when the operation switch is operated while the semiconductor switch is off.
According to the rechargeable fan device configured as such, even when the power source to the control unit is shut off and thus the control unit is in an operation stoppage state, when a user operates the operation switch to turn on the semiconductor switch, power supply to the control unit is thereby started and the control unit starts operating. Therefore, it is possible to rapidly start driving the fan to rotate.
Moreover, according to such a configuration, it is possible to rapidly activate the control unit, which has stopped operating because of shut-off of power supply due to fulfillment of the shutdown conditions, either by DC power input through the DC jack or by an operation of the operation switch.
It is preferable that the control unit is designed to control the semiconductor switch to turn on at a predetermined timing after start of operation. This enables the control unit to continue power supply to itself by performing control (on-control of the semiconductor switch) once the operation is started, and to thereby perform a stable operation.
While various specific configurations of the voltage generation unit can be conceived, the following configuration is preferable, for example. Specifically, the voltage generation unit may be configured to include a regulator that generates the control voltage based on the DC power inputted; and a power source selection unit that supplies the regulator with either the DC power from the DC power source supplied via the second supply path or the DC power from the battery supplied via the first supply path, whichever has a higher voltage value.
Specifically, it is not the case that a regulator for generating a control voltage based on DC power supplied externally via the DC jack and a regulator for generating a control voltage based on DC power of the battery are provided separately, but it is designed that a control voltage is generated by a single regulator. As for which DC power is to be used to generate a control voltage, the power source selection unit performs such a selection.
According to the rechargeable fan device configured as such, the voltage generation unit can be realized with a simple configuration and, thus, downsizing and cost reduction of the entire device become possible.
It is preferable that the control unit includes an input determination unit, a conditions determination unit, and a charge control unit as specific components that control charging of the battery. The input determination unit determines whether or not DC power is inputted through the DC jack after start of operation of the control unit itself. The conditions determination unit determines whether or not the battery satisfies the predetermined charging execution conditions when the input determination unit has determined that DC power is inputted through the DC jack. The charge control unit controls charging of the battery by the DC power through the DC jack when the conditions determination unit has determined that the charging execution conditions are satisfied.
According to the rechargeable fan device configured as such, even when the control unit is in an operation stoppage state, the control unit is rapidly activated upon input of the DC power through the DC jack, and executes charging if the charging execution conditions are satisfied. Therefore, it is possible to start charging rapidly and reliably by input of the DC power into the DC jack.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be described below with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view showing an external appearance of a handy cleaner according to an embodiment;

FIG. 2 is a block diagram showing a circuit configuration of a battery pack and a control circuit board;

FIG. 3 is an explanatory diagram for explaining a flow until a control circuit is activated;

FIG. 4 is a flowchart showing a motor drive and charge control processing executed by the control circuit; and

FIG. 5 is a perspective view showing an external appearance of a rechargeable blower according to a modified example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present embodiment is configured by applying the present invention to a rechargeable electric cleaning device (hereinafter referred to as “handy cleaner”) 1, which is operated by receiving power from a repeatedly rechargeable battery.
As shown in FIG. 1, the handy cleaner 1 of the present embodiment includes a suction port 3, an outlet port 4, and a grip portion 5. The suction port 3 is provided at a leading end portion of a body case 2 formed in a cylindrical shape, and suctions outside air. The outlet port 4 is provided in a side wall of the body case 2, and dust-removed air is discharged through the outlet port 4. The grip portion 5 is provided on a rear end side of the body case 2 and is hand-held by a user.
At an upper end portion of the grip portion 5, an electronic switch 10 is provided so that a user can operate the handy cleaner 1 while gripping the grip portion 5. In front of the electronic switch 10, an LED 14 is provided that lights up when a battery 25 (see FIG. 2) is being charged.
The electronic switch 10 includes two operation switches that become an on-state when operated (pressed) by a user and become an off-state when not operated by a user. One of the two operation switches is set as a drive switch 11 that inputs a drive command, and the other is set as a stop switch 12 that inputs a stop command.
Although not directly illustrated in FIG. 1, within the body case 2 of the handy cleaner 1, a suction fan 6, a motor 7, a battery pack 20, and a control circuit board 30 are provided.
The suction fan 6 is provided to suction outside air into the body case 2 through the suction port 3 and then to discharge the suctioned outside air through the outlet port 4. The suction fan 6 is disposed in a position facing the suction port 3 with a filter housing portion (not shown) located therebetween. The filter housing portion houses therein a filter for removing dust from the suctioned outside air.
The motor 7 is a DC motor in the present embodiment, and is disposed on an opposite side of the suction port 3 with respect to the suction fan 6. To a rotational axis of the motor 7, the suction fan 6 is connected. This enables the motor 7 to rotate the suction fan 6 by rotation of the motor 7 itself and to thereby cause outside air to be suctioned into the body case 2.
As shown in FIG. 2, the battery pack 20 is configured such that the battery 25 and a cell temperature detecting thermistor 26 are housed in a battery case of synthetic resin (not shown). The battery 25 is constituted by serially connecting a plurality (three in the present embodiment) of chargeable/dischargeable lithium-ion battery cells (hereinafter simply referred to as “cells”) 21, 22, 23. The cell temperature detecting thermistor 26 detects temperatures of the respective cells 21 to 23. As shown in FIG. 1, the battery pack 20 is housed in a battery pack housing portion (not shown) formed on a lower rear end side in the body case 2 of the handy cleaner 1.
Specifically, in the handy cleaner 1, a cover body 8 is attachably and detachably provided in a lower end portion of the grip portion 5 (in a rear end portion of the body case 2). When the cover body 8 is detached from the body case 2, there appears an opening portion on a rear end of the body case 2. By inserting the battery pack 20 through the opening portion, the battery pack 20 can be housed in the battery pack housing portion.
On an upper portion of the side wall of the body case 2, a DC jack 9 is provided, and on an upper face side of the body case 2, the LED 14 is provided. The control circuit board 30 is disposed above the motor 7 as well as in an adjacent position to the electronic switch 10 and to the LED 14 within the body case 2.
As shown in FIG. 2, the control circuit board 30 has various electronic components assembled thereto that perform charging of the battery 25 by receiving power from an AC adapter 50, as well as perform discharging to the motor 7 (in other words, driving of the motor 7) by receiving power from the battery 25.
The AC adapter 50 is designed to generate a DC voltage (DC power) for charging the battery 25 by receiving power from an AC power source and to supply a constant charging current via the control circuit board 30, and is configured as a separate body from the handy cleaner 1.
Thus, the DC jack 9 is provided on the upper portion of the side wall of the body case 2, and by inserting into the DC jack 9 a DC plug 51 provided at a leading end of a power cord pulled out from the AC adapter 50, it is possible to supply DC power from the AC adapter 50 to the control circuit board 30.
Next, a description will be given about a circuit configuration of the control circuit board 30. As shown in FIG. 2, the control circuit board 30 has a discharge path formed therein that allows current to flow from a positive side of the battery 25 to a negative side of the battery 25 via the motor 7.
On a negative side of the motor 7 in the discharge path, a discharge control FET 15 is provided that controls discharge current from the battery 25 to the motor 7 (i.e., drive current of the motor 7).
Furthermore, the control circuit board 30 has a charging path formed therein that connects a positive side terminal (+) of the AC adapter 50 to the positive side of the battery 25 and connects a negative side terminal (−) of the AC adapter 50 to the negative side of the battery 25.
Provided in the charging path extending from the positive side terminal (+) of the AC adapter 50 to the positive side of the battery 25 are a backflow suppression diode 43, a charge control FET 16, and a charge protection FET 17 that protects the battery 25 from overcurrent.
The discharge control FET 15, the charge control FET 16, and the charge protection FET 17 are each a switching element that brings the discharge path or the charging path into/out of conduction, and are driven by a control circuit 31 that controls charging/discharging, of the battery 25. The backflow suppression diode 43 is designed to suppress backflow of electric current from the battery 25 to the AC adapter 50, and an anode is connected to a side of the AC adapter 50 and a cathode is connected to the positive side of the battery 25.
In the present embodiment, the discharge control FET 15 is an N-channel MOSFET, and a drain thereof is connected to a side of the motor 7. The charge control FET 16 and the charge protection FET 17 are both P-channel MOSFETs, and drains thereof are connected to the positive side of the battery 25.
The control circuit 31 is constituted by a microcomputer (micon) mainly composed of a CPU, a ROM, a RAM, and the like. The control circuit 31 performs driving of the motor 7 and charging of the battery 25 by turning on/off each of the above-described FETs 15 to 17 in accordance with various control programs stored in the ROM.
Specifically, the control circuit 31 generates a PWM signal (pulse width modulated signal) of a predetermined duty ratio in accordance with either of high/low drive commands (Hi/Lo shown in FIG. 2) inputted by a user via the drive switch 11, and outputs the generated PWM signal to the discharge control FET 15.
As a result, a current according to the drive command flows through the motor 7, and the motor 7 rotates at a rate corresponding to the current.
As shown in FIG. 2, the drive switch 11 is a normally-open type switch (so-called an a-contact switch), and one end thereof is connected to a base of a drive input transistor 47, and the other end thereof is connected to a base of a battery power supply switch 18. The drive input transistor 47 is an NPN-type bipolar transistor in the present embodiment. To a collector, a control voltage Vc (details will be described later) is applied via a resistor 46, and an emitter is grounded. The collector of the drive input transistor 47 is connected to the control circuit 31, and an electric potential of the collector is inputted into the control circuit 31 as a drive input signal. Due to such a configuration, in a case where the control voltage Vc is applied to the collector of the drive input transistor 47, when the drive switch 11 is off, the drive input signal to be inputted into the control circuit 31 becomes high level (the control voltage Vc). On the other hand, when the drive switch 11 is turned on, the drive input transistor 47 is turned on and, therefore, the drive input signal to be inputted into the control circuit 31 becomes low level (ground potential). The control circuit 31 determines an on/off state of the drive switch 11 based on a level of the drive input signal.
The stop switch 12 is also a normally-open type switch (an a-contact switch). The control voltage Vc is applied to one end of the stop switch 12 via a resistor 48, and the one end is connected to the control circuit 31, whereas the other end is grounded. An electric potential of the one end of the stop switch 12 is inputted into the control circuit 31 as a stop input signal. Due to such a configuration, in a case where the control voltage Vc is applied to the one end of the stop switch 12 via the resistor 48, when the stop switch 12 is off, the stop input signal to be inputted into the control circuit 31 becomes high level, and when the stop switch 12 is turned on, the stop input signal to be inputted into the control circuit 31 becomes low level. The control circuit 31 determines an on/off state of the stop switch 12 based on a level of the stop input signal.
When the drive switch 11 is press-operated for the first time after a start of operation, or when the drive switch 11 has been press-operated at a start of operation, the control circuit 31 recognizes that a high-speed drive command (Hi) is inputted as a drive command from the drive switch 11. Then, by duty-driving the discharge control FET 15 at a predetermined duty ratio for high-speed driving, the control circuit 31 causes the motor 7 to rotate at a high speed.
When the drive switch 11 is press-operated while the motor 7 is rotated at the high speed at the duty ratio for high-speed driving, the control circuit 31 recognizes that a low-speed drive command (Lo) is inputted as a drive command from the drive switch 11. Then, by duty-driving the discharge control FET 15 at a predetermined duty ratio for low-speed driving, which is lower than that for high-speed driving, the control circuit 31 switches the motor 7 to a low-speed rotation.
When the drive switch 11 is press-operated while the motor 7 is rotated at a high speed at the duty ratio for low-speed driving, the control circuit 31 recognizes that a high-speed drive command (Hi) is inputted as a drive command from the drive switch 11. Then, by duty-driving the discharge control FET 15 at the duty ratio for high-speed driving, the control circuit 31 switches the motor 7 to a high-speed rotation.
As described above, every time a user press-operates the drive switch 11, the control circuit 31 alternately switches a speed of rotation of the motor 7 between high-speed rotation and low-speed rotation. When a user press-operates the stop switch 12 to thereby input the stop command, the control circuit 31 brings the discharge control FET 15 into an off-state and stops driving the motor 7.
In a case where the AC adapter 50 is connected at stoppage of driving of the motor 7 and where an, output voltage from the battery 25 is lower than a threshold voltage for determining start of charging, the control circuit 31 switches the charge control PET 16 and the charge protection FET 17 from an off-state to an on-state to thereby start charging the battery 25.
Charge control of the battery 25 by the control circuit 31 is continued until the battery 25 is brought into a fully charged state. When the battery 25 is brought into a fully charged state, the charge control FET 16 and the charge protection FET 17 are switched to an off-state, and the charging of the battery 25 is completed.
When the drive switch 11 is press-operated during charging of the battery 25, the control circuit 31 discontinues the charge control. Then, the control circuit 81 recognizes that a high-speed drive command (Hi) is inputted as a drive command from the drive switch 11, and duty-drives the discharge control FET 15 at the predetermined duty ratio for high-speed driving, to thereby cause the motor 7 to rotate at the high speed.
When a stop command is inputted from the stop switch 12 during driving of the motor 7, the control circuit 31 stops the motor 7. At this time, the control circuit 31 determines necessity of charging of the battery 25 by determining whether or not an output voltage from the battery 25 is lower than the threshold voltage. If such charging is necessary, the control circuit 31 restarts the charge control.
In short, even when the AC adapter 50 is connected to the DC jack 9, it is possible to operate the handy cleaner 1 of the present embodiment as an electric cleaning device by operation of the electronic switch 10.
When performing the charge/discharge control as described above, the control circuit 31 monitors an output voltage of each of the cells 21 to 23 constituting the battery 25 and temperature of the battery 25 in addition to an output voltage from the battery 25. When any abnormality is found in these, the control circuit 31 brings the charge protection FET 17 and the discharge control FET 15 into an off-state, to thereby stop charge/discharge of the battery 25.
For this purpose, the control circuit board 30 has a cell voltage detection unit 32 provided thereon that detects output voltage of each of the cells 21 to 23 of the battery 25, and a detection signal indicating a voltage of each of the cells 21 to 23 is inputted into the control circuit 31 from the cell voltage detection unit 32.
The control circuit board 30 also has a protection circuit 34 provided thereon that imports the voltage of each of the cells 21 to 23 of the battery 25 and forcibly turns off the charge control FET 16 when the imported voltage has reached a threshold value greater than a value for determination of overvoltage during charging by the control circuit 31 (i.e., when an overvoltage protection by the control circuit 31 does not function normally). The control circuit board 30 further has a disconnection detection unit 33 provided thereon that detects disconnection within the battery 25 from a cell voltage detected by the cell voltage detection unit 32 by setting connection portions between the respective cells 21 to 23 in the battery 25 to have a predetermined electric potential. When detecting disconnection within the battery 25 using the disconnection detection unit 33, the control circuit 31 prohibits charge/discharge of the battery 25.
Furthermore, the control circuit board 30 has a regulator 35 provided thereon that supplies a power-supply voltage (DC constant voltage) to each of the above-described circuits provided in the control circuit board 30, such as the control circuit 31.
The regulator 35 is designed to be able to be supplied with DC voltage from both the battery 25 and the AC adapter 50 via two diodes 36, 37. The regulator 35 generates the DC constant voltage (the control voltage) Vc using the DC voltage supplied from either of the battery 25 and the AC adapter 50, and supplies the control voltage Vc to each of the above-described circuits as a power-supply voltage.
Since it is configured such that the DC voltage from the battery 25 and the DC voltage from the AC adapter 50 are each inputted into the regulator 35 via the respective diodes, the DC power actually supplied to the regulator 35 is either from the battery 25 or from the AC adapter 50, whichever has a higher voltage value.
However, in a path on an upstream side (anode side) of the diode 36 in a current-carrying path extending from a positive electrode of the battery 25 to the regulator 35, the battery power supply switch 18 is provided. The battery power supply switch 18 is a PNP-type bipolar transistor in the present embodiment. An emitter is connected to the positive electrode of the battery 25, a collector is connected to an anode of the diode 36, and a base is connected to a collector of a base control transistor 19 and to one end of the drive switch 11. A base of the base control transistor 19 is connected to the control circuit 31, and an emitter is grounded. The base control transistor 19 is an NPN-type bipolar transistor in the present embodiment.
Due to such a configuration, the DC power supply from the battery 25 to the regulator 35 is to be performed when the battery power supply switch 18 is on. The battery power supply switch 18 is basically controlled by the control circuit 31. Specifically, when the control circuit 31 is operating, the base control transistor 19 is turned on by the control circuit 31, and the battery power supply switch 18 is thereby also turned on.
On the other hand, in a case where predetermined shutdown conditions are satisfied during operation of the control circuit 31, the control circuit 31 turns off the battery power supply switch 18 by turning off the base control transistor 19, to thereby shut off the DC power supply from the battery 25 to the regulator 35.
The shutdown conditions include, for example, a case in which a state where the motor 7 is in stoppage and where the AC adapter 50 is not connected to the DC jack 9 continues for a given period of time; a case in which a state where charging of the battery 25 is completed and not being performed although the AC adapter 50 is connected and where the motor 7 is also in stoppage continues for a given period of time; a case in which a given period of time has elapsed since the electronic switch 10 is no longer operated; a case in which a state where charging is not performed while the AC adapter 50 is connected continues for a given period of time; and a case in which the cell voltage (or the battery voltage) has become an overdischarge state. It goes without saying that these are only examples.
When the shutdown conditions are satisfied, the control circuit 31 cuts off the battery power supply switch 18 to stop operation of the control circuit 31 itself, and transitions to a shutdown state. Once the control circuit 31 has transitioned to a shutdown state, the control circuit 31 cannot turn on the battery power supply switch 18 by itself.
However, by connecting the AC adapter 50 to the DC jack 9 and supplying DC power from the DC jack 9 via the diode 37, the regulator 35 generates the control voltage Vc from the DC power and supplies the generated control voltage Vc to the control circuit 31. This enables the control circuit 31 to be activated. Since the control circuit 31 turns on the battery power supply switch 18 after activation, even when the AC adapter 50 is removed from the DC jack 9 after activation of the control circuit 31, the control circuit 31 allows an output of the control voltage Vc from the regulator 35 to be maintained by battery power, to thereby enable continuation of operation.
Furthermore, in the present embodiment, the base of the battery power supply switch 18 is connected to the one end of the drive switch 11. Therefore, if a user press-operates the drive switch 11 when the control circuit 31 is in a shutdown state, the base of the battery power supply switch 18 and a base of the drive input transistor 47 are brought into conduction, and the battery power supply switch 18 and the drive input transistor 47 are thereby turned on. Due to this, battery power is supplied to the regulator 35, and the control voltage Vc is generated by the regulator 35.
In short, it is possible to turn on the battery power supply switch 18 also by a press-operation of the drive switch 11, independently of control by the control circuit 31.
When performing charge control of the battery 25 by receiving power from the regulator 35, the control circuit 31 causes the LED 14 to light up to inform a user accordingly.
The control circuit board 30 has a circuit provided thereon constituted by an AC adaptor detecting transistor 44, a resistor 45, and the like. The circuit detects connection of the AC adapter 50 (specifically, detects a DC power input from the AC adapter 50) and informs the control circuit 31 of such a connection. Specifically, in the AC adaptor detecting transistor 44, a base is connected to a positive side of the AC adapter 50 in the charging path (specifically, to a cathode side of the backflow suppression diode 43); and an emitter is grounded. To a collector, the control voltage Vc is applied via the resistor 45, and the collector is also connected to the control circuit 31. An electric potential of the collector is inputted into the control circuit 31 as an AC adapter detection signal. The AC adaptor detecting transistor 44 is an NPN-type bipolar transistor in the present embodiment.
Due to such a configuration, in a case where the AC adapter 50 is not connected when the control voltage Vc is applied to the collector of the AC adaptor detecting transistor 44, the AC adaptor detecting transistor 44 is turned off, and the AC adapter detection signal to be inputted into the control circuit 31 becomes high level. On the other hand, when the AC adapter 50 is connected and DC power is inputted from the AC adapter 50, the AC adaptor detecting transistor 44 is turned on and, therefore, the AC adapter detection signal to be inputted into the control circuit 31 becomes low level. The control circuit 31 determines presence/absence of connection of the AC adapter 50 based on a level of the AC adapter detection signal.
The control circuit 31 also monitors temperature of the battery 25. For this temperature monitoring, a detection signal from the cell temperature detecting thermistor 26 provided within the battery pack 20 and a detection signal from a board temperature detecting thermistor 39 provided on the control circuit board 30 are utilized.
Such a configuration is taken so that, even if either of the two kinds of thermistors 26, 39 is out of order, it can be detected that the battery 25 is out of a chargeable temperature range based on the detection signal from either of the thermistors during charging of the battery 25.
Specifically, the battery 25 has a problem that, for example, when the battery 25 is charged at a temperature below 0° C., lithium ions emitted from a positive electrode become poorly absorbed by a negative electrode and lithium metal thereby tends to deposit.
Therefore, the present embodiment is designed such that the control circuit 31 executes a predetermined temperature checking processing during charging of the battery 25, thereby to monitor whether or not the battery 25 is normally in a chargeable temperature range using the above-described two thermistors 26, 39.
In the present embodiment, in order to import detection signals from the two thermistors 26, 39 into the control circuit 31, one analog port and two digital ports provided in the control circuit 31 are utilized.
This is because the microcomputer constituting the control circuit 31 has a low number of analog ports and there is only one analog port that can A/D-convert each temperature detection signal (analog signal) from each of the thermistors 26, 39 and can import the A/D-converted signal.
Each of the thermistors 26, 39 is a known temperature sensor having a property that a resistance value changes with temperature. Therefore, the present embodiment is designed such that one end of the cell temperature detecting thermistor 26 and one end of the board temperature detecting thermistor 39 are connected to the one analog port of the control circuit 31 and, to the connection portion, the control voltage Vc supplied from the regulator 35 is applied via a resistor 38.
The other end of the cell temperature detecting thermistor 26 and the other end of the board temperature detecting thermistor 39 are connected to the two respective digital ports of the control circuit 31. Specifically, as shown in FIG. 2, the other end of the cell temperature detecting thermistor 26 is connected to one end of a cell-side low side switch 41 via the digital port of the control circuit 31, and the other end of the board temperature detecting thermistor 39 is connected to one end of a board-side low side switch 42 via the digital port of the control circuit 31. The other ends of the respective low side switches 41, 42 are both grounded.
Due to such a configuration, when the control circuit 31 detects temperature via these respective thermistors 26, 39, either of the low side switches to which targeted thermistor is connected is brought into an on-state, and the other end of the targeted thermistor is thereby grounded.
In this way, the control circuit 31 can monitor temperature of the battery 25 using the two thermistors, i.e., the cell temperature detecting thermistor 26 provided within the battery pack 20 and the board temperature detecting thermistor 39 provided on the control circuit board 30.
Next, in particular from among operations of the handy cleaner 1 of the present embodiment, a description will be given with reference to FIG. 3 about specific flows (activation sequences) in which the control circuit 31 is activated from a shutdown state.
In order to activate the control circuit 31 from a state in which the control circuit 31 is shut down to make the battery power supply switch 18 off as well as in which the AC adapter 50 is not connected, it is sufficient to connect the AC adapter 50 to the DC jack 9 or to press-operate the drive switch 11.
Of these, the activation sequence in the case where the AC adapter 50 is connected to the DC jack 9 is as is shown on the left side of FIG. 3. Specifically, when the AC adapter 50 is connected to the DC jack 9 (S11) while the control circuit 31 is in a shutdown state, DC power from the AC adapter 50 is supplied from the DC jack 9 to the regulator 35 via the respective diodes 43, 37 (S12). This activates the regulator 35 (S13), and the control voltage Vc is generated by the regulator 35 and supplied to the control circuit 31 (S14). This activates the control circuit 31 (S15). When activated, the control circuit 31 performs a predetermined initializing processing and thereafter brings the battery power supply switch 18 into an on-state. The control circuit 31 keeps the battery supply switch 18 in the on-state during operation of the control circuit 31.
On the other hand, the activation sequence in the case where the drive switch 11 is press-operated by a user is as is shown on the right side of FIG. 3. Specifically, if the drive switch 11 is on-operated (press-operated) (S21) while the control circuit 31 is in a shutdown state, the base of the battery power supply switch 18 is electrically conducted to the base of the drive input transistor 47 via the drive switch 11, and the battery power supply switch 18 is thereby turned on together with the drive input transistor 47 (S22). As a result, battery power is supplied from the battery 25 to the regulator 35 via the battery power supply switch 18 and the diode 36 (S23). This activates the regulator 35 (S24), and the control voltage Vc is generated by the regulator 35 and supplied to the control circuit 31 (S25). This activates the control circuit 31 (S26). Also in such a case, the control circuit 31 first performs the predetermined initializing processing after activation, and thereafter brings the battery power supply switch 18 into an on-state. The control circuit 31 keeps the battery power supply switch 18 in the on-state during operation of the control circuit 31.
Next, a description will be given with reference to FIG. 4 about operations, after activation of the control circuit 31, i.e., about a motor drive and charge control processing executed by the control circuit 31. The control circuit 31 performs the predetermined initializing processing after activation, and thereafter starts the motor drive and charge control processing as shown in FIG. 4.
Upon starting the motor drive and charge control processing, the control circuit 31 first determines an activation factor of itself in S110. Specifically, the control circuit 31 determines whether the activation of itself is due to connection of the AC adapter 50 or due to press-operation of the drive switch 11. As described above, the AC adapter detection signal indicating presence/absence of connection of the AC adapter 50 is inputted into the control circuit 31. If the AC adapter detection signal is low level, the control circuit 31 determines that the AC adapter 50 is connected (i.e., that the activation of the control circuit 31 itself is due to connection of the AC adapter 50).
On the other hand, if the drive switch 11 is in an on-state, the control circuit 31 determines that the activation of itself is due to press-operation of the drive switch 11 based on the drive input signal inputted from the drive switch 11.
When determining that the activation factor of itself is due to connection of the AC adapter 50, the control circuit 31 brings the battery power supply switch 18 into an on-state and keeps the battery power supply switch 18 in the on-state in S120. Since this enables the regulator 35 to be also supplied with power from the battery 25, even when the AC adapter 50 is removed from the DC jack 9, generation of the control voltage Vc by the regulator 35 is continued by virtue of the battery power, and the control circuit 31 can also thereby continue operation.
In S130, the control circuit 31 determines whether or not the charging execution conditions are satisfied. Specifically, when an output voltage from the battery 25 is lower than the threshold voltage for determining start of charging, the control circuit 31 determines that the charging execution conditions are satisfied. When determining that the charging execution conditions are satisfied, the control circuit 31 executes charging of the battery 25 in S140. Specifically, as described above, the control circuit 31 executes the charging of the battery 25 by switching the charge control FET 16 and the charge protection FET 17 from an off-state to an on-state.
The charging execution conditions may include at least either of a case where cell temperature detected by the cell temperature detecting thermistor 26 is within a predetermined range and a case where board temperature detected by the board temperature detecting thermistor 39 is within a predetermined range. These exemplified charging execution conditions are just examples, and other charging execution conditions may be set.
Then, the control circuit 31 determines in S150 whether or not the drive switch 11 has been on-operated (press-operated), and if the drive switch 11 has not been on-operated, the control circuit 31 determines in S160 whether or not charging has been completed. Specifically, the control circuit 31 determines whether or not the battery 25 is brought to a fully charged state. If the charging has not been completed, the process returns to S140 and the charging is continued. If the charging has been completed, the process proceeds to S170. When the drive switch 11 is on-operated by a user during execution of the charging, the process proceeds from S150 to S200 and the charging is discontinued. Then, the process proceeds to S220 and the control circuit 31 executes driving of the motor 7.
On the other hand, when determining in S130 that the charging execution conditions are not satisfied and when determining in S160 that the charging has been completed, the control circuit 31 determines in S170 whether or not a given period of time has elapsed since such determinations were made in S130 or in S160, i.e., whether or not a preparation for shutdown has been completed (shutdown conditions are satisfied). If the given period of time has not elapsed yet, the control circuit 31 determines in S180 whether or not the drive switch 11 has been on-operated. If the drive switch 11 has been on-operated before the given period of time has elapsed, the process proceeds to S220 and the control circuit 31 executes driving of the motor 7.
If the given period of time has elapsed without on-operation of the drive switch 11, the process proceeds to S190 and the control circuit 31 performs shutdown. Specifically, the control circuit 31 turns off the battery power supply switch 18 to stop operation of the control circuit 31 itself.
On the other hand, when determining in S110 that the activation factor of itself is due to a press-operation of the drive switch 11, the control circuit 31 brings the battery power supply switch 18 into an on-state and keeps the battery power supply switch 18 in the on-state in S210.
Then, the control circuit 31 executes driving of the motor 7 in S220. Specifically, as described above, the control circuit 31 causes the motor 7 to rotate by PWM-driving the discharge control FET 15. When such a motor drive in S220 is executed for the first time after start of the motor drive and charge control processing, the control circuit 31 causes the motor 7 to rotate at the high speed at the duty ratio for high-speed driving.
Subsequently, the control circuit 31 determines in S230 whether or not the drive switch 11 has been on-operated by a user. If the drive switch 11 has been on-operated, the control circuit 31 switches a PWM duty ratio in S240 from a duty ratio at this time to the other duty ratio. Specifically, when such a processing in S240 is executed in a state where, for example, the duty ratio is set to that for high-speed driving, the control circuit 31 switches the duty ratio to that for low-speed driving. In contrast, when such a processing in S240 is executed in a state where the duty ratio is set to that for low-speed driving, the control circuit 31 switches the duty, ratio to that for high-speed driving. After the duty ratio has been switched, the process returns to S220, and the control circuit 31 drives the motor 7 at the switched duty ratio.
If the drive switch 11 has not been on-operated in S230, the control circuit 31 determines in S250 whether or not the stop switch 12 has been on-operated. If the stop switch 12 has not been on-operated, the process returns to S220 and the control circuit 31 continues to drive the motor 7. If the stop switch 12 has been on-operated, the control circuit 31 stops driving the motor 7 in S260.
Then, the control circuit 31 determines in S270 whether or not the AC adapter 50 is connected to the DC jack 9. If the AC adapter 50 is connected, the process proceeds to S130, and if the AC adapter 50 is not connected, the process proceeds to S170. In this case, the control circuit 31 determines in S170 whether or not a given period of time has elapsed since the determination is made in S270 that the AC adapter 50 is not connected. If the given period of time has elapsed without on-operation of the drive switch 11, the control circuit 31 performs shutdown in S190.
According to the handy cleaner 1 of the present embodiment, as described above, a conventional operation such as detachment of the battery pack 20 from the device body in order to charge the battery 25 is unnecessary, and it is possible to charge the battery 25 just by connecting the AC adapter 50 to the DC jack 9 and inputting DC power from the AC adapter 50. Therefore, charging of the battery 25 can be easily performed without extra effort. Charging of the battery 25 can be performed not only via the DC jack 9 but also by removing the battery pack 20 from the device body and setting the battery pack 20 onto a given charger.
If the shutdown conditions are satisfied during operation of the control circuit 31 (YES in S170), the control circuit 31 turns off the battery power supply switch 18 to thereby stop operation of the control circuit 31 itself. That is, the control circuit 31 no longer consumes any power of the battery 25. Consequently, even when the battery pack 20 is kept in an attached state to the device body, the battery 25 can be made to last longer.
While the control circuit 31 is in a shutdown state, when the AC adapter 50 is connected to the DC jack 9 to input DC power or when a user on-operates the drive switch 11, the DC power is supplied to the regulator 35 and the regulator 35 is operated. The regulator 35 generates the control voltage Vc and supplies the generated control voltage Vc to the control circuit 31. This enables the control circuit 31 to be activated rapidly and, thus, charging of the battery 25 or driving of the motor 7 can be performed rapidly.
Moreover, when the control circuit 31 is activated and performs the predetermined initializing processing and the like, the control circuit 31 keeps the battery power supply switch 18 in an on-state by performing control. Therefore, even when the drive switch 11 is turned off after activation of the control circuit 31, or even when the AC adapter 50 is removed from the DC jack 9, the control circuit 31 can continue operation.
Furthermore, the DC power from the battery 25 and the DC power from the DC jack 9 are inputted not into respective separate regulators, but into one same regulator, i.e., the regulator 35, via the diodes 36, 37, respectively. Since the regulator 35 is provided one in number by using the diodes in such a manner, downsizing and cost reduction of the entire device are achieved.
In the present embodiment, the two diodes 36, 37, cathodes of which are connected to the regulator 35, correspond to an example of the power source selection unit of the present invention; the battery power supply switch 18 corresponds to an example of the semiconductor switch of the present invention; a path extending from the positive electrode of the battery 25 to the diode 36 via the battery power supply switch 18 corresponds to an example of the first supply path of the present invention; a path extending from a positive side of the DC jack 9 to the diode 37 for selecting input power source via the backflow suppression diode 43 corresponds to an example of the second supply path of the present invention; the control circuit 31 corresponds to an example of the control unit of the present invention; the drive switch 11 corresponds to an example of the operation switch of the present invention; and a path extending from the base of the battery power supply switch 18 to the ground potential via the drive switch 11 and the drive input transistor 47 corresponds to an example of the switch-on unit of the present invention.
In the motor drive and charge control processing in FIG. 4, the processing in S110 corresponds to an example of the processing, executed by the input determination unit of the present invention; the processing in S130 corresponds to an example of the processing executed by the conditions determination unit of the present invention; and the processing in S140 corresponds to an example of the processing executed by the charge control unit of the present invention.

MODIFIED EXAMPLE

Although a description has been given above about the embodiment of the present invention, it goes without saying that modes for carrying out the present invention are not limited to the above embodiment, and the present invention can be practiced in various forms as long as they pertain to the technical scope of the present invention.
For example, although a case where the present invention is applied to the rechargeable handy cleaner 1 has been described in the above embodiment, the present invention can be applied to any dust collection device provided with a battery in a manner similar to the above embodiment.
The present invention can also be applied, in a manner similar to the above embodiment, for example to an air discharging device that discharges gas, such as a rechargeable blower 60 as shown in FIG. 5, which is used to blow off dust by discharging high-pressure air.
Here, the rechargeable blower 60 shown in FIG. 5 is constituted by a nozzle 62 of a cylindrical shape, a blower body 63, and a battery pack 64. Provided at a leading end of the nozzle 62 is an outlet port 61 through which high-pressure air is discharged. A rear end side of the nozzle 62 is attached to the blower body 63. The battery pack 64 is attachably and detachably attached to the blower body 63.
On a side wall of the blower body 63, an intake port 65 is provided that introduces outside air. On an upper portion of the blower body 63, a grip portion 66 to be hand-held by a user is provided. In the blower body 63, provided on a side opposite to the nozzle 62 is an attachment portion 67 to which the battery pack 64 is attached.
On a leading end portion of the grip portion 66 on a side of the nozzle 62, an electronic switch 68 to be operated by a user is provided in a manner similar to the electronic switch 10 of the above embodiment.
Provided within the blower body 63 are a discharge fan 71, a motor 72, a control circuit board 73, and the like. The discharge fan 71 introduces outside air through the intake port 65 and discharges the introduced outside air to the side of the nozzle 62. The motor 72 rotates the discharge fan 71. The control circuit board 73 is operated by receiving power from the battery pack 64 and controls driving of the motor 72 in response to a drive command from the electronic switch 68.
In the rechargeable blower 60 configured as such, too, effects similar to the above embodiment can be obtained if a control circuit constituted by a microcomputer is mounted on the control circuit board 73 and if the control circuit is designed to control a semiconductor device (an FET, a bipolar transistor, or the like) provided in a current-carrying path extending from the battery pack 64 to the motor 72 in a manner similar to the control circuit 31 of the above embodiment.
In the above embodiment, a bipolar transistor is used as the battery power supply switch 18 and the respective transistors 44, 47, and a MOSFET is used as the respective control FETs 15 to 17. However, these are just examples and other kinds of switches can be used as long as they perform similar functions.
Moreover, the configuration in which the base of the battery power supply switch 18 is made to be a ground potential by on-operation of the drive switch 11 to thereby turn on the battery power supply switch 18 is also just an example. Various other specific configurations in which the battery power supply switch 18 is turned on by on-operation of the drive switch 11 can be conceived.

Claims

What is claimed is:

1. A rechargeable fan device comprising:

a fan that suctions or discharges gas;

a motor that drives the fan to rotate;

a battery that supplies power to the motor;

a voltage generation unit that generates a control voltage of a predetermined voltage value based on DC power inputted;

a first supply path used to supply DC power from the battery to the voltage generation unit;

a semiconductor switch that brings the first supply path into/out of conduction;

a DC jack used to input DC power from an external DC power source;

a second supply path used, when the DC power is inputted into the DC jack, to supply the DC power to the voltage generation unit; and

a control unit that is operated using, as a power source, the control voltage generated by the voltage generation unit, the control unit being configured: to control driving of the motor by controlling power supply from the battery to the motor; to control charging of the battery by DC power if predetermined charging execution conditions are satisfied when the DC power is inputted into the DC jack; and to shut off power supply from the battery to the voltage generation unit by turning off the semiconductor switch if predetermined shutdown conditions are satisfied during operation of the control unit itself.

2. The rechargeable fan device according to claim 1, comprising:

an operation switch to be operated by a user in order to drive the fan to rotate; and

a switch-on unit that supplies DC power from the battery to the voltage generation unit by turning on the semiconductor switch when the operation switch is operated while the semiconductor switch is off.

3. The rechargeable fan device according to claim 1,

wherein the control unit controls the semiconductor switch to turn on at a predetermined timing after start of operation.

4. The rechargeable fan device according to claim 1,

wherein the voltage generation unit includes:

a regulator that generates the control voltage based on the DC power inputted, and

a power source selection unit that supplies the regulator with either the DC power from the DC power source supplied via the second supply path or the DC power from the battery supplied via the first supply path, whichever has a higher voltage value.

5. The rechargeable fan device according to claim 1,

wherein the control unit includes:

an input determination unit that determines whether or not DC power is inputted through the DC jack after start of operation of the control unit itself;

a conditions determination unit that determines whether or not the battery satisfies the predetermined charging execution conditions when the input determination unit has determined that DC power is inputted through the DC jack; and

a charge control unit that controls charging of the battery by the DC power through the DC jack when the conditions determination unit has determined that the charging execution conditions are satisfied.