Backpack-type blower

The present international application claims the benefit of Japanese Patent Application No. 2015-085922 filed on Apr. 20, 2015 with the Japanese Patent Office, and the entire disclosure of Japanese Patent Application No. 2015-085922 is incorporated herein by reference.

The present disclosure relates to a backpack-type blower that is supplied with electric power from a battery to operate.

Conventionally, a backpack-type blower is known in which a fan that is rotationally driven by a motor and a battery that supplies electric power to the fan are mounted on a backpack and a user may carry the backpack-type blower on the back by means of the backpack to use (refer to, for example, Patent Document 1).

Patent Documents

Patent Document 1: US6006400

Problems to be Solved by the Invention

In the above-described conventional backpack-type blower, a pair of the motor and fan is mounted on the backpack, and accordingly, air blowing capability from the blower is determined by a size of the fan and a rotational speed of the motor.

Therefore, in order to increase the blowing capability, it is necessary to make the fan larger or increase the rotational speed of the motor. However, if the blowing capability is increased by such a method, there is a problem that not only the blower becomes larger but also noise generated during operation becomes large, so that usage is inconvenient.

According to one aspect of the present disclosure, it is preferable to increase the air blowing capability while inhibiting the noise generated during operation in the backpack-type blower.

Means for Solving the Problems

A backpack-type blower according to one aspect of the present disclosure includes a plurality of fans each including a corresponding motor and a plurality of DC power supplies for supplying electric power to each fan and is configured to blow winds from the plurality of fans together.

Therefore, it is possible to increase air blowing capability from the blower without increasing a rotational speed of each fan (in other words, a rotational speed of the motor) by the plurality of fans, and eventually, the generation of noise can be inhibited.

Since electric power is supplied from each of a plurality of DC power supplies to each fan, usable time (so-called run time) from a fully charged state of the battery can be lengthened as compared to a case where electric power is supplied from one battery to each fan (motor).

Therefore, the backpack-type blower of the present disclosure can improve usability as compared with the conventional one.

Herein, each of the plurality of DC power supplies may also be configured to supply electric power to a corresponding fan via an independent power supply path.

In this manner, it is possible to inhibit current from flowing between the DC power supplies via the power supply path to the fan when output voltages vary among the plurality of DC power supplies.

Furthermore, for example, even if one of the plurality of fans is put into an abnormal state such as high temperature and the driving of the fan is stopped, the other fan(s) can be normally driven and it is possible to inhibit breakdown of the same as the blower.

Negative electrodes of the plurality of DC power supplies may also be configured to have the same electric potential.

In this manner, reference potential of various circuits used for connecting or blocking the power supply path from the DC power supply to the corresponding fan (motor) and for controlling motor current flowing through the path can be made the same, so that a circuit configuration may be simplified.

Each DC power supply may also be formed of a plurality of batteries.

In this case, it is better to couple the plurality of batteries in series rather than in parallel.

That is, if the plurality of batteries is coupled in series, drive voltage supplied from the DC power supply to the fan (motor) is raised, so that it is possible to inhibit the current flowing through the power supply path to decrease power loss occurring in the power supply path.

The backpack-type blower according to one aspect of the present disclosure may be provided with a controller that monitors states of a plurality of DC power supplies or a plurality of fans and, when detecting abnormality that rotation of at least one of the plurality of fans cannot be continued, stops the rotation of the at least one fan.

In this manner, it is possible to stop the rotation of the motor when at least one fan cannot be normally driven due to lowering of a remaining power amount accumulated in the DC power supply (hereinafter also simply referred to as “remaining capacity”) or failure of at least one fan (motor). If the rotation of the motor is stopped in this manner, it is possible to inhibit overdischarging of the battery forming the DC power supply or burnout of the motor due to overcurrent flowing through the motor.

The controller may also be configured to increase a rotational speed of the other fan(s) when the rotation of the at least one fan in which the abnormality is detected is stopped. In this manner, it is possible to inhibit an air blowing amount from the backpack-type blower from lowering.

In this case, the controller may also be configured to control the rotational speed of the other fan(s) so that the blowing amount from the backpack-type blower is the same as that before the rotation of the at least one fan in which the abnormality is detected is stopped.

The controller may also be configured to control the electric power supplied from each DC power supply to each fan according to the remaining capacity indicating the remaining amount of electric power accumulated in each DC power supply.

In this manner, for example, in a case where two DC power supplies and two fans are mounted on the backpack-type blower and a ratio of the remaining capacities of the two DC power supplies is 1:2, it is possible to control such that the ratio of the electric power supplied to the two fans supplied with the electric power from each DC power supply is also 1:2. Therefore, in this case, it is possible to efficiently use the electric power of each DC power supply.

Next, as the motor provided in each of the plurality of fans, it is preferable to use a brushless motor excellent in durability that can be efficiently driven.

In order to drive the brushless motor, it is necessary to detect a rotational position of the motor. However, if a sensor is used for this detection, the number of wires coupled to the fan increases.

Therefore, when the brushless motor is provided for each fan, a sensorless motor not provided with a sensor for detecting the rotational position may also be used. In this case, the rotational position may be detected by a conventionally known sensorless method such as a method of detecting induced voltage generated by the rotation of the motor.

It is preferable that the motor provided in each fan is controlled to constantly rotate by a driving unit. In this manner, the motor (eventually the fan) can be rotated at a constant speed, and air can be stably blown from the blower.

In order to stabilize the air blowing amount from the blower in this manner, it is preferable to form the motor provided in each fan as an outer rotor motor. Since the outer rotor motor has larger moment of inertia than that of an inner rotor motor and the rotation of the rotor is stable, it is possible to stably rotate the fan at a constant speed.

FIG. 1 is a configuration diagram illustrating a configuration of an entire backpack-type blower according to an embodiment.

FIG. 2 is a cross-sectional view of a blower main body as seen in the same direction as FIG. 1 .

FIG. 3 is an illustrative view of an interior of the blower main body as seen from the left of FIG. 2 .

FIG. 4 is a block diagram illustrating a circuit configuration of the backpack-type blower according to the embodiment.

FIG. 5 is a block diagram illustrating a circuit configuration of a driving controller.

FIG. 6 is a flowchart illustrating a control process executed by a centralized management controller.

FIG. 7 is a block diagram illustrating a variation of the circuit configuration of the driving controller.

2 . . . blower, 4 . . . backpack, 6 . . . blower main body, 7 . . . pipe attaching unit, 8 , 8 a to 8 e . . . pipe, 9 . . . blowing port, 10 A, 10 B . . . fan, 12 A, 12 B . . . motor, 20 . . . handle unit, 22 . . . trigger SW, 22 a . . . main SW, 22 b . . . variable resistance portion, 24 . . . dial SW, 26 . . . lock button, 28 . . . main power supply SW, 30 . . . display unit, DA, DB . . . light emitting diode, 32 , 42 A, 42 B . . . cable, 34 , 44 A, 44 B . . . connector, 40 . . . centralized management controller, 50 A, 50 B . . . DC power supply, 50 A 1 , 50 A 2 , 50 B 1 , 50 B 2 . . . battery pack, 52 A, 52 B . . . remaining capacity display unit, 60 A, 60 B . . . driving controller, 62 . . . inverter circuit, 64 . . . rotational position sensor, 66 , 68 . . . temperature sensor, 70 . . . control circuit, 72 . . . rotor position detection unit, 74 . . . rotor rotational speed calculation unit, 76 . . . PWM generation unit, 78 . . . switching control unit, 80 . . . state monitoring unit, 82 , 84 . . . battery state detection unit

Mode for Carrying Out the Invention

An embodiment of the present disclosure is hereinafter described with reference to the drawings.

As illustrated in FIG. 1 , a backpack-type blower (hereinafter also simply referred to as a blower) 2 of this embodiment is provided with a blower main body 6 mounted on a backpack 4 , and a pipe 8 for guiding air blown from the blower main body 6 to a blowing port 9 at a tip end thereof and blowing the air from the blowing port 9 .

As illustrated in FIG. 2 , fans 10 A and 10 B which rotate around a common central axis A to introduce air from both end sides of the central axis A and send the air in the same direction are accommodated in the blower main body 6 .

The blower main body 6 is provided with a pipe attaching unit 7 for collecting winds from the fans 10 A and 10 B and blowing the winds to the pipe 8 (refer to FIG. 3 ).

The fans 10 A and 10 B are provided with outer rotor-type brushless motors (hereinafter simply referred to as motors) 12 A and 12 B, respectively, and fixed to rotors of the motors 12 A and 12 B, respectively.

The motors 12 A and 12 B having the same structure are arranged to face in opposite directions on the central axis A such that outside air can be introduced from the both end sides of the central axis A by the rotation of the fans 10 A and 10 B. The motors 12 A and 12 B rotate in the same direction around the central axis A by being driven so that rotational directions thereof are opposite to each other.

The fans 10 A and 10 B take in the outside air from the both end sides of the central axis A by the rotation of the motors 12 A and 12 B in the same direction around the central axis A, and blow the taken-in air from the pipe attaching unit 7 in the same direction.

The blower main body 6 is fixed to the backpack 4 via a spring 5 for absorbing vibration, and the backpack 4 is provided with a shoulder pad 4 a and a belt 4 b for a user to put the same on the shoulder.

In the blower main body 6 , the pipe attaching unit 7 is provided so as to be located on a right side of the user when the user carries the blower main body 6 on the back via the backpack 4 .

Next, the pipe 8 is formed of pipes 8 a to 8 e obtained by dividing the pipe 8 into five pipes along a central axis thereof.

Among them, the pipe 8 a can be detachably mounted on the pipe attaching unit 7 and is formed into an L shape such that a blowing direction of air from the blower main body 6 can be changed from a lateral direction of the user to a forward direction thereof.

The pipe 8 b connected to the pipe 8 a is formed into a bellows shape such that a direction of the blowing port 9 can be appropriately changed.

The pipe 8 c connected to the pipe 8 b is a straight pipe, and a handle unit 20 is provided on an outer periphery of the pipe 8 c such that the user can grip the handle unit 20 to adjust the direction of the blowing port 9 . Moreover, the handle unit 20 is slidable in a direction of a central axis of the pipe 8 c and can be fixed at an appropriate position to be used.

The pipe 8 c can be connected to either the straight pipe 8 d or the pipe 8 e whose tip end is formed to have a small diameter as the blowing port 9 . When the pipe 8 d is connected to the pipe 8 c , the pipe 8 e can be connected to a tip end of the pipe 8 d.

Next, the handle unit 20 is provided with various operation switches so as to be operated by a finger when the user grips the handle unit 20 .

That is, the handle unit 20 is provided with a trigger switch (switch is hereinafter referred to as SW) 22 for adjusting a blowing amount of air from the blower 2 and a dial SW 24 for setting a maximum blowing amount adjustable by operation of the trigger SW 22 . The handle unit 20 is also provided with a lock button 26 for holding the trigger SW 22 at a maximum operation position, and a main power supply SW 28 and a display unit 30 for displaying an operation state illustrated in FIG. 4 .

As illustrated in FIG. 4 , the trigger SW 22 , the dial SW 24 , the main power supply SW 28 , and the display unit 30 are coupled to a centralized management controller 40 fixed to the backpack 4 together with the blower main body 6 via a cable 32 and a connector 34 .

The centralized management controller 40 is formed of a well-known microcomputer including a CPU, a ROM, a RAM, an input/output port and the like.

The trigger SW 22 is also provided with a main SW 22 a that is turned on when operated by the user and a variable resistance portion 22 b whose resistance value changes according to an amount of the operation by the user.

The centralized management controller 40 applies power supply voltage Vd to the variable resistance portion 22 b and takes in divided voltage by sliding contact of the variable resistance portion 22 b as a trigger shift command.

The dial SW 24 is formed of variable resistor whose resistance value varies according to a rotational position of the dial.

The centralized management controller 40 applies the power supply voltage Vd to the variable resistor and takes in the divided voltage by the sliding contact of the variable resistor as a dial shift command.

Also, when the main SW 22 a of the trigger SW 22 is turned on, the centralized management controller 40 sets rotational speeds of the fans 10 A and 10 B (in other words, the motors 12 A and 12 B).

Specifically, the rotational speed is set by multiplying a ratio corresponding to the trigger shift command (that is, divided voltage) taken in from the variable resistance portion 22 b of the trigger SW 22 by the rotational speed corresponding to the dial shift command taken in from the dial SW 24 as a maximum rotational speed.

The main power supply SW 28 is a momentary SW (normally off). When the main power supply SW 28 is turned on by the operation by the user, an internal power supply circuit thereof is turned on/off (in other words, the same is operated/stopped).

When the various SWs 22 , 24 , and 28 are not operated for a certain period of time, the centralized management controller 40 automatically turns off the internal power supply circuit.

The display unit 30 is provided with light emitting diodes (LEDs) DA and DB which are turned on by energization from the centralized management controller 40 when the centralized management controller 40 can drive the fans 10 A and 10 B respectively.

Next, DC power supplies 50 A and 50 B used for driving the motors 12 A and 12 B, respectively, are formed of two battery packs 50 A 1 and 50 A 2 , and 50 B 1 and 50 B 2 , respectively, illustrated in FIG. 3 and FIG. 4 .

The two battery packs 50 A 1 and 50 A 2 , and 50 B 1 and 50 B 2 are coupled to the controllers 60 A and 60 B for driving the motors 12 A and 12 B, respectively, and are coupled in series inside each of the driving controllers 60 A and 60 B (refer to FIG. 5 ).

As illustrated in FIG. 3 , the battery packs 50 A 1 , 50 A 2 , 50 B 1 , and 50 B 2 are arranged in this order from a left side to a right side below the blower main body 6 when the blower main body 6 is seen from behind the backpack 4 .

As illustrated in FIG. 2 , the driving controllers 60 A and 60 B ( 60 A is illustrated in the drawing) are arranged on a front side of the backpack 4 as compared to a portion on which the battery packs 50 A 1 , 50 A 2 , 50 B 1 , and 50 B 2 ( 50 A 2 is illustrated in the drawing) are mounted in the blower main body 6 .

As illustrated in FIG. 3 , since the driving controller 60 A is required to be coupled to the battery packs 50 A 1 and 50 A 2 , this is arranged on a left side of the blower main body 6 when the blower main body 6 is seen from behind the backpack 4 . Similarly, since the driving controller 60 B is required to be coupled to the battery packs 50 B 1 and 50 B 2 , this is arranged on a right side of the blower main body 6 .

The centralized management controller 40 drives the motors 12 A and 12 B (and eventually the fans 10 A and 10 B) via the driving controllers 60 A and 60 B, respectively. Therefore, the centralized management controller 40 is coupled to the driving controllers 60 A and 60 B via cables 42 A and 42 B and connectors 44 A and 44 B, respectively.

The centralized management controller 40 is required to be coupled to the various SWs 22 , 24 , and 28 and the display unit 30 of the handle unit 20 provided on the pipe 8 via the cable 32 . Therefore, as is the case with the pipe attaching unit 7 , the centralized management controller 40 is arranged on the right side when the blower main body 6 is seen from behind the backpack 4 .

Specifically, as is the case with the driving controllers 60 A and 60 B, the centralized management controller 40 is arranged on the front side of the backpack 4 as compared to the portion on which the battery packs 50 A 1 to 50 B 2 are mounted. When the blower main body 6 is seen from behind the backpack 4 , the centralized management controller 40 is arranged to the right of the driving controller 60 B (refer to FIG. 3 ).

As a result, the cable 42 A coupling the centralized management controller 40 to the driving controller 60 A can be made longer than the cable 42 B coupling the centralized management controller 40 to the driving controller 60 B.

In this embodiment, by making the cables 42 A and 42 B to have different lengths in this manner, wiring mistakes caused when they are made to have the same length are inhibited.

That is, the centralized management controller 40 outputs various signals to the driving controllers 60 A and 60 B via the cables 42 A and 42 B, respectively. Specifically, the centralized management controller 40 outputs a main SW signal, speed commands of the motors 12 A and 12 B, and F/R signals indicating the rotational directions of the motors 12 A and 12 B taken in from the trigger SW 22 and the dial SW 24 .

The centralized management controller 40 takes in driving permission signals for permitting driving of the motors 12 A and 12 B and remaining capacity lowering signals indicating lowering of remaining capacities of the DC power supplies 50 A and 50 B from the driving controllers 60 A and 60 B via the cables 42 A and 42 B, respectively.

The centralized management controller 40 also takes in power supply voltages VbatA and VbatB of the DC power supplies 50 A and 50 B (voltages between both ends of the two batteries coupled in series) from the driving controllers 60 A and 60 B via the cables 42 A and 42 B.

Therefore, when the driving controllers 60 A and 60 B are coupled in an opposite manner via the cables 42 A and 42 B, for example, the F/R signal problematically becomes a command signal for rotating in the direction opposite to the air blowing direction (that is, suction direction).

On the other hand, if the centralized management controller 40 is arranged as described above and the cables 42 A and 42 B between the same and the driving controllers 60 A and 60 B are set to have different lengths as in this embodiment, such a problem caused by the wiring mistakes can be inhibited.

Input lines of the power supply voltages VbatA and VbatB of the DC power supplies 50 A and 50 B from the driving controllers 60 A and 60 B to the centralized management controller 40 are formed of pairs of positive and negative signal lines coupled to positive electrode sides and negative electrode sides of the DC power supplies 50 A and 50 B. The signal lines on the negative electrode sides are coupled to ground lines of the centralized management controller 40 .

Accordingly, the negative electrode sides of the DC power supplies 50 A and 50 B have the same electric potential via the centralized management controller 40 . As is described later, since ground lines of the driving controllers 60 A and 60 B are also coupled to the negative electrode sides of the corresponding DC power supplies 50 A and 50 B, the ground lines of the centralized management controller 40 and the driving controllers 60 A and 60 B also have the same electric potential.

Configurations of the driving controllers 60 A and 60 B are next described.

As illustrated in FIG. 5 , in the driving controllers 60 A and 60 B, positive electrode terminals of the battery packs 50 A 1 and 50 B 1 are coupled to the power supply lines on the positive electrode side for driving the motors 12 A and 12 B.

Also, negative electrode terminals of the battery packs 50 A 2 and 50 B 2 are coupled to the ground lines on the negative electrode side and the negative electrode terminals of the battery packs 50 A 1 and 50 B 1 and the positive electrode terminals of the battery packs 50 A 2 and 50 B 2 are coupled in the driving controllers 60 A and 60 B, respectively.

Each of the driving controllers 60 A and 60 B is provided with an inverter circuit 62 and a control circuit 70 .

The inverter circuit 62 is supplied with electric power from the power supply line and the ground line and energizes windings of each phase of the motors 12 A and 12 B.

Therefore, the inverter circuit 62 is provided with three switching elements (so-called high-side switches) Q 1 , Q 2 , and Q 3 provided between the power supply line and connection points of the windings of each phase of the motors 12 A and 12 B.

Also, the inverter circuit 62 is provided with three switching elements (so-called low-side switches) Q 4 , Q 5 , and Q 6 provided between the connection points of the windings of each phase of the motors 12 A and 12 B and the ground line.

The control circuit 70 is configured to control an on/off state of each of the switching elements Q 1 to Q 6 forming the inverter circuit 62 , and is formed of a well-known microcomputer including a CPU, a ROM, a RAM, an input/output port and the like.

In the control circuit 70 , the CPU executes various control processes in accordance with a control program stored in the ROM, thereby serving as a rotor position detection unit 72 , a rotor rotational speed calculation unit 74 , a PWM generation unit 76 , and a switching control unit 78 .

Herein, the rotor position detection unit 72 detects rotational positions (phases) of the motors 12 A and 12 B based on detection signals from rotational position sensors 64 provided on the motors 12 A and 12 B.

The rotor rotational speed calculation unit 74 calculates the rotational speeds of the motors 12 A and 12 B from changes in the rotation positions detected by the rotor position detection unit 72 .

The PWM generation unit 76 generates a gate driving signal (PWM signal) required for driving the motors 12 A and 12 B at the rotational speeds corresponding to the speed commands based on the speed command signals input from the centralized management controller 40 and the rotational speeds calculated by the rotor rotational speed calculation unit 74 . PWM stands for Pulse Width Modulation.

When the main SW signal is input from the centralized management controller 40 to the switching control unit 78 , the switching control unit 78 controls the respective switching elements Q 1 to Q 6 of the inverter circuit 62 based on the PWM signal generated by the PWM generation unit 76 , thereby driving the motors 12 A and 12 B.

Specifically, in accordance with the F/R signals input from the centralized management controller 40 , the switching control unit 78 controls the respective switching elements Q 1 to Q 6 so that rotational directions of the motors 12 A and 12 B become a positive direction or a negative direction.

Each of the driving controllers 60 A and 60 B is provided with a state monitoring unit 80 .

The state monitoring unit 80 is configured to monitor states of battery state detection units 82 and 84 , a temperature sensor 68 that detects temperature of the driving controllers 60 A and 60 B, a temperature sensor 66 that detects temperature of the motors 12 A and 12 B and the like based on detection signals therefrom. The battery state detection units 82 and 84 detect the temperature, remaining capacity and the like of the battery packs 50 A 1 and 50 A 2 or 50 B 1 and 50 B 2 .

When determining that the motors 12 A and 12 B can be normally driven from a monitoring result thereof, the state monitoring unit 80 outputs a driving permission signal to the centralized management controller 40 . Otherwise, the state monitoring unit 80 stops the output of the driving permission signal.

When determining that the remaining capacity of the battery packs 50 A 1 and 50 A 2 or 50 B 1 and 50 B 2 lowers, the state monitoring unit 80 outputs a remaining capacity lowering signal to the centralized management controller 40 .

Also, a remaining capacity display unit 52 A or 52 B illustrated in FIG. 4 is coupled to the state monitoring unit 80 , and the state monitoring unit 80 outputs first and second remaining capacity display signals indicating the remaining capacity of the battery packs 50 A 1 and 50 A 2 or 50 B 1 and 50 B 2 to the remaining capacity display unit 52 A or 52 B.

As a result, the remaining capacity of the battery packs 50 A 1 and 50 A 2 or 50 B 1 and 50 B 2 is displayed on the remaining capacity display units 52 A or 52 B, and the user can check the remaining capacity of the battery packs 50 A 1 and 50 A 2 or 50 B 1 and 50 B 2 from the display.

The remaining capacity display units 52 A and 52 B are provided on the blower main body 6 .

As described above, in the blower 2 of this embodiment, when the trigger SW 22 provided in the handle unit 20 is operated to turn on the main SW 22 a , the centralized management controller 40 sets the rotational speeds of the fans 10 A and 10 B (in other words, the motors 12 A and 12 B).

Then, the centralized management controller 40 outputs the speed command signals corresponding to the set rotational speeds to the driving controllers 60 A and 60 B, thereby rotationally driving the motors 12 A and 12 B (eventually, the fans 10 A and 10 B) in the direction where air is blown.

Driving control of the motors 12 A and 12 B by the centralized management controller 40 is executed by a procedure illustrated in FIG. 6 .

As illustrated in FIG. 6 , at the time of driving control of the motors 12 A and 12 B, the centralized management controller 40 takes in the driving permission signals from the driving controllers 60 A and 60 B of the motors 12 A and 12 B at S 110 .

At subsequent S 120 , it is determined whether the driving of the motor 12 A is permitted based on the driving permission signal from the driving controller 60 A. If the driving is permitted, the procedure shifts to S 130 , and if the driving is not permitted, the procedure shifts to S 250 .

Next, at S 130 , it is determined whether the driving of the motor 12 B is permitted based on the driving permission signal from the driving controller 60 B. If the driving is permitted, the procedure shifts to S 140 , and if the driving is not permitted, the procedure shifts to S 190 .

Since the driving of the motors 12 A and 12 B is currently permitted at S 140 , the rotational speeds of the motors 12 A and 12 B are set to command rotational speeds set based on the trigger shift command from the trigger SW 22 and the dial shift command from the dial SW 24 .

At subsequent S 150 and S 160 , the speed command signals corresponding to the rotational speeds set at S 140 are output to the driving controllers 60 A and 60 B, respectively. As a result, the motors 12 A and 12 B rotate at constant speeds at the command rotational speeds set via the trigger SW 22 and the dial SW 24 .

At subsequent S 170 and S 180 , since the motors 12 A and 12 B are normally driven, the light emitting diodes DA and DB of the display unit 30 are turned on so as to indicate that they are normally driven, and then the procedure shifts to S 110 again.

Next, at S 190 , since the driving of the motor 12 B is currently prohibited, the rotational speed of the motor 12 A is set to an added value obtained by adding the command rotational speeds set for the respective motors 12 A and 12 B to each other, and the procedure shifts to S 200 . The rotational speed of the motor 12 B at this time is “0”.

At S 200 , it is determined whether the rotational speed set at S 190 exceeds the maximum rotational speed of the motor 12 A set in advance. If the set rotational speed does not exceed the maximum rotational speed, the procedure shifts to S 210 .

The maximum rotational speed used at S 200 is not the rotational speed set via the dial SW 24 but the maximum rotational speed at which the driving is permitted according to specifications of the motor 12 A.

Next, at S 200 , if it is determined that the set rotational speed exceeds the maximum rotational speed, the rotational speed of the motor 12 A is set to the maximum rotational speed at S 205 , and then the procedure shifts to S 210 .

At S 210 , the speed command signal corresponding to the rotational speed set in the processes at S 190 to S 205 is output to the driving controller 60 A. As a result, the motor 12 A rotates at a constant speed at the rotational speed obtained by adding the command rotational speed of the motor 12 A and the command rotational speed of the motor 12 B set via the trigger SW 22 and the dial SW 24 .

At subsequent S 220 , by stopping the output of the speed command signal to the driving controller 60 B or by outputting the speed command signal of “rotational speed: 0” to the driving controller 60 B, the driving of the motor 12 B is stopped.

At subsequent S 230 , the light emitting diode DA of the display unit 30 is turned on, and at subsequent S 240 , the light emitting diode DB of the display unit 30 is turned off. Then, the procedure shifts to S 110 . As a result, the user can detect by looking at the display unit 30 that there currently is abnormality in a driving system of the fan 10 B and only the fan 10 A rotates.

When a drive output of the fan 10 B is lowered due to the lowering of the remaining capacity of the battery packs 50 B 1 and 50 B 2 , the centralized management controller 40 detects this by the remaining capacity lowering signal and blinks the light emitting diode DB of the display unit 30 .

Therefore, the user can also detect the lowering of the remaining capacity of the battery packs 50 B 1 and 50 B 2 by checking the display unit 30 .

Next, at S 250 , similarly to S 130 , it is determined whether the driving of the motor 12 B is permitted based on the driving permission signal from the driving controller 60 B, and if the driving is permitted, the procedure shifts to S 260 .

At S 260 , since the driving of the motor 12 A is currently prohibited and the driving of the motor 12 B is currently permitted, the rotational speed of the motor 12 B is set to an added value obtained by adding the command rotational speeds set for the respective motors 12 A and 12 B, and the procedure shifts to S 270 . The rotational speed of the motor 12 A at this time is “0”.

At S 270 , it is determined whether the rotational speed set at S 260 exceeds the maximum rotational speed of the motor 12 B set in advance. If the set rotational speed does not exceed the maximum rotational speed, the procedure shifts to S 280 .

The maximum rotational speed used at S 270 is the maximum rotational speed at which the driving is permitted according to specifications of the motor 12 B, as is the case at S 200 .

Next, at S 270 , if it is determined that the set rotational speed exceeds the maximum rotational speed, the rotational speed of the motor 12 B is set to the maximum rotational speed at S 275 , and then the procedure shifts to S 280 .

At S 280 , by stopping the output of the speed command signal to the driving controller 60 A or by outputting the speed command signal of “rotational speed: 0” to the driving controller 60 A, the driving of the motor 12 A is stopped.

Then, at subsequent S 290 , the speed command signal corresponding to the rotational speed set in the processes at S 260 to S 275 is output to the driving controller 60 B. As a result, the motor 12 B rotates at a constant speed at the rotational speed obtained by adding the command rotational speed of the motor 12 A and the command rotational speed of the motor 12 B set via the trigger SW 22 and the dial SW 24 .

Next, at subsequent S 300 , the light emitting diode DA of the display unit 30 is turned off, and at subsequent S 310 , the light emitting diode DB of the display unit 30 is turned on. Then, the procedure shifts to S 110 . As a result, the user can detect by looking at the display unit 30 that there currently is abnormality in a driving system of the fan 10 A and only the fan 10 B rotates.

When the drive output of the fan 10 A is lowered due to the lowering of the remaining capacity of the battery packs 50 A 1 and 50 A 2 , the centralized management controller 40 detects this by the remaining capacity lowering signal and blinks the light emitting diode DA of the display unit 30 .

Therefore, the user can also detect the lowering of the remaining capacity of the battery packs 50 A 1 and 50 A 2 by checking the display unit 30 .

Next, at S 250 , when it is determined that the driving of the motor 12 B is not permitted, driving of both the motors 12 A and 12 B is prohibited, so that the driving of the motors 12 A and 12 B is stopped at S 320 and S 330 .

At S 320 and S 330 , by stopping the output of the speed command signals to the driving controllers 60 A and 60 B or by outputting the speed command signals of “rotational speed: 0” to the driving controllers 60 A and 60 B, the driving of the motors 12 A and 12 B is stopped.

At subsequent S 340 and S 350 , since both the motors 12 A and 12 B are stopped, the light emitting diodes DA and DB of the display unit 30 are turned off so as to indicate this and thereafter the procedure shifts to S 110 again.

As described above, the blower 2 of this embodiment is provided with the pair of fans 10 A and 10 B. The driving controllers 60 A and 60 B provided for the fans 10 A and 10 B, respectively, are supplied with electric power from dedicated DC power supplies 50 A and 50 B to drive the motors 12 A and 12 B of the fans 10 A and 10 B, respectively.

Therefore, the air (wind) blown from the blowing port 9 of the pipe 8 is generated by the rotation of the two fans 10 A and 10 B, and air blowing capability can be increased as compared with a blower in which only one fan and one motor are provided. Also, if the blowing capability is the same, the generation of noise can be inhibited.

As compared with a case where electric power is supplied from a common DC power supply to the fans 10 A and 10 B (motors 12 A and 12 B), the power consumption of the batteries forming the DC power supplies 50 A and 50 B can be reduced. Therefore, usable time (so-called run time) from a fully charged state of the battery can be lengthened.

In this embodiment, the DC power supplies 50 A and 50 B are coupled to the driving controllers 60 A and 60 B, respectively, and the driving controllers 60 A and 60 B individually drive the motors 12 A and 12 B, respectively.

Therefore, even if the voltages supplied from the DC power supplies 50 A and 50 B are uneven, current does not flow from one DC power supply to the other DC power supply. Therefore, for example, even if abnormality occurs in the driving system of one of the motors 12 A and 12 B and the fan thereof stops, the other motor can be driven to operate as the blower 2 .

Especially, in this embodiment, when abnormality occurs in the driving system of one motor, the driving controller stops the output of the driving permission signal, thereby notifying the centralized management controller 40 of this.

Then, the centralized management controller 40 sets the rotational speed of the motor that can be normally driven to twice the rotational speed at the normal time with the maximum rotational speed set in advance as an upper limit.

As a result, according to this embodiment, even if an abnormality occurs in the driving system of one motor, the air blowing amount from the blowing port 9 of the blower 2 can be controlled to the blowing amount required by the user by the operation of the trigger SW 22 .

Therefore, according to the blower 2 of this embodiment, it is possible to inhibit deterioration of a function as the blower 2 when an abnormality occurs in the driving system of one motor.

Power supply voltages are input to the centralized management controller 40 from the positive electrode sides and the negative electrode sides of the DC power supplies 50 A and 50 B via the driving controllers 60 A and 60 B, and the negative electrode sides of the DC power supplies 50 A and 50 B are coupled to the ground lines of the centralized management controller 40 .

Therefore, the electric potential of the ground lines of the centralized management controller 40 and the driving controllers 60 A and 60 B and the electric potential of the negative electrode sides of the DC power supplies 50 A and 50 B can be made the same.

Therefore, reference potential of a control system when the centralized management controller 40 drives the motors 12 A and 12 B via the driving controllers 60 A and 60 B can be made the same and design work when constructing the control system can be simplified.

In this embodiment, the state monitoring unit 80 in each of the driving controllers 60 A and 60 B and the centralized management controller 40 correspond to the control unit described above, and the inverter circuit 62 and the control circuit 70 in each of the driving controllers 60 A and 60 B correspond to the driving unit described above.

Although one embodiment of the present disclosure is described above, the backpack-type blower of the present disclosure is not limited to the above-described embodiment and may take various modes.

For example, in the above-described embodiment, it is described that the rotation position sensor 64 is provided in each of the motors 12 A and 12 B and the rotor position detection unit 72 detects the rotation position (phase) of each of the motors 12 A and 12 B based on the detection signal from the rotation position sensor 64 .

However, as illustrated in FIG. 7 , each of the motors 12 A and 12 B may be a sensorless motor that is not provided with the rotational position sensor 64 . In this case, the rotor position detection unit 72 detects the rotational position based on induced voltage generated in a current path from the inverter circuit 62 to the motors 12 A and 12 B.

This makes it possible to decrease the number of signal lines coupling the motors 12 A and 12 B and the driving controllers 60 A and 60 B, thereby making wiring work easy.

In the above-described embodiment, it is described that, when the motors 12 A and 12 B may be normally driven, the centralized management controller 40 controls the rotational speeds of the motors 12 A and 12 B to the command rotational speeds set via the trigger SW 22 and the dial SW 24 .

Since the DC power supply 50 A for driving the motor 12 A and the DC power supply 50 B for driving the motor 12 B are separately charged and discharged, remaining power amounts (that is, remaining capacities) accumulated in the DC power supplies 50 A and 50 B might be uneven.

Therefore, if the rotational speeds of the motors 12 A and 12 B are controlled to be the same, unevenness may occur in time during which the motors 12 A and 12 B can be driven.

Therefore, the state monitoring unit 80 of each of the driving controllers 60 A and 60 B may notify the centralized management controller 40 of the remaining capacity of each of the DC power supplies 50 A and 50 B. Then, the centralized management controller 40 sets the command rotational speed for each of the motors 12 A and 12 B in accordance with difference (ratio or the like) of the notified remaining capacities in the process at S 140 .

That is, by doing so, the electric power supplied from the DC power supplies 50 A and 50 B to the motors 12 A and 12 B, respectively, is controlled such that time until the remaining capacities of the DC power supplies 50 A and 50 B reach a threshold for determining motor drive is the same.

In this manner, it is possible to efficiently use the electric power of each DC power supply and control the air blowing amount from the blowing port 9 to the blowing amount according to the user's request.

In the above-described embodiment, the DC power supplies 50 A and 50 B are described to be used for the motors 12 A and 12 B, respectively.

However, for example, when any one of the motors 12 A and 12 B (or the fans 10 A and 10 B) fails and electric power sufficient for driving the motor is accumulated in the DC power supply corresponding to the failed motor, the DC power supply may be used for driving the other motor.

That is, by switching the connection by the centralized management controller 40 or the driving controllers 60 A and 60 B, the above-described DC power supplies 50 A and 50 B or the battery packs 50 A 1 to 50 B 2 forming the same may be used to drive the other motor 12 B or 12 A.

Next, in the above-described embodiment, each of the DC power supplies 50 A and 50 B is described to be formed by coupling the two battery packs 50 A 1 and 50 A 2 or 50 B 1 and 50 B 2 in series.

However, each of the DC power supplies 50 A and 50 B may be formed of one battery pack or three or more battery packs. In the case where the DC power supplies 50 A and 50 B are formed of a plurality of battery packs, the battery packs need not be coupled in series, but may be coupled in parallel.

In the above-described embodiment, the motors 12 A and 12 B for rotating the fans 10 A and 10 B are described as the outer rotor-type brushless motor. However, the motors 12 A and 12 B are not necessarily configured in this manner as long as they are the motors that can rotationally drive the fans 10 A and 10 B.

In the above-described embodiment, the fans 10 A and 10 B are described being arranged side by side such that the central axes thereof are coincident with each other, and outside air is introduced from both sides thereof. However, the fans need not be arranged in this manner. For example, the fans may be arranged so that an introducing direction of the outside air is the same direction (for example, behind the user). Also, the number of fans is not necessarily two, and may be three or more.