JP2007054146A - Vacuum cleaner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum cleaner having lower noises of a sucking utensil for reducing the problem that the rotation number is higher on a wooden floor having less load with an increase of noises of a motor, and that the splashing of refuse by jetting often occurs when the suction force is small. <P>SOLUTION: This vacuum cleaner is equipped with the suction utensil having a rotating brush, the motor which rotates the rotating brush, and a back electromotive detecting means which detects a back electromotive voltage of the motor. When a load on a wooden floor or the like is small a wooden floor, the motor is operated by reducing the application voltage, and when the motor turns locked by a load from a floor surface, the motor is rotated by releasing the locking by raising the application voltage. Thus, the application voltage of the motor can be made variable by the load from the floor surface, and noises can be reduced by suppressing power when the load is small. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vacuum cleaner, and more particularly to the quietness of an electric motor built in a suction tool.

Conventionally, in this type of vacuum cleaner, as shown in FIG. 8, a control circuit 104 having an electric blower 102 and a signal processing unit 103 is built in the vacuum cleaner main body 101, and the hand operating unit 105 and the vacuum cleaner main body 101 are connected. The hose 106, the electric motor 108 built in the suction tool 107, the rotating brush 109 that scoops up the dust rotated by the electric motor 108, and the extension pipe 110 that connects the suction tool 107 and the hand operation unit 105, The operation unit 105 controls the suction force control of the electric blower 102 and the presence / absence of rotation of the electric motor 108. Further, in order to reduce the number of hose core wires and the number of contacts, one side of the commercial power supply is connected to the motor 108, and the power source and the hand operation signal are transmitted with reference to the wire. In addition, there is one that detects the current of the electric motor and stops the electric motor when overcurrent occurs (for example, see Patent Document 1).
JP 2002-248070 A

  However, in the conventional configuration, the applied voltage of the rotating brush is constant with respect to the suction force, and the applied voltage is also constant on the floor surface, so that dust removal is ensured under heavy load such as carpets. In order to achieve this, it is necessary to rotate the motor at a certain speed or higher, and the motor is set under these conditions. Therefore, the motor speed is increased on a lightly loaded wooden floor, and the motor noise is increased. There was a defect that caused blow-off.

  The present invention solves the above-mentioned conventional problems, and operates the rotating brush motor of the suction tool with an applied voltage that matches the floor surface, thereby suppressing the noise of the motor and further reducing the blowing of dust. Provide a high vacuum cleaner.

  In order to solve the above-mentioned conventional problems, the vacuum cleaner of the present invention comprises a rotating brush for scraping dust to a suction tool, an electric motor for rotating the rotating brush, and an electric motor driving means for changing an applied voltage of the electric motor. And a back electromotive force detecting means for detecting a back electromotive voltage of the electric motor, and when the load on the wooden floor is small, the applied voltage is lowered to operate, and a load change of the carpet or the like, or a user removes the suction tool on the floor surface. When the load becomes heavy due to being pressed against the motor and the motor is locked, the applied voltage is increased to release the lock and rotate the motor.

  This makes it possible to operate the motor by increasing the applied voltage on a floor surface with a heavy load on the carpet, and to operate the motor by decreasing the applied voltage on a floor surface with a light load such as a wooden floor.

  The vacuum cleaner of the present invention operates the motor by increasing the applied voltage on a heavy floor surface on the carpet, so that the dust removal is satisfied and the applied voltage is on a light floor surface such as a wooden floor. When the electric motor is operated with lowering, the number of rotations is suppressed, noise is reduced, and dust blowing is also reduced. Further, since the operation is performed with the applied voltage according to the floor surface, not only the excessive power is suppressed, but also the fluctuation of the power supply voltage can be automatically dealt with.

  According to a first aspect of the present invention, there is provided a rotating brush for scraping dust to a suction tool, an electric motor for rotating the rotating brush, electric motor driving means for changing an applied voltage of the electric motor, and a reverse for detecting a counter electromotive voltage of the electric motor. When the load on the wooden floor is small, it is operated by lowering the applied voltage, and the load is heavy when the load of the carpet, etc. is changed or the user presses the suction tool against the floor, and the motor locks. In this state, the applied voltage is increased to release the lock, and the motor is rotated, so that the applied voltage is increased on the floor where the load on the carpet is heavy and the motor operates so that the garbage can be removed. On a floor surface with a light load such as a wooden floor, by operating the electric motor by lowering the applied voltage, the number of rotations is reduced, noise is reduced, and dust blowing is also reduced. Further, since the operation is performed with the applied voltage according to the floor surface, not only the excessive power is suppressed, but also the fluctuation of the power supply voltage can be automatically dealt with.

  2nd invention detects the counter electromotive voltage of the rotating brush for sweeping up dust to a suction tool, the electric motor which rotates the rotating brush, the electric motor drive means which varies the applied voltage of the electric motor, and the rotating brush Equipped with a back electromotive force detection means, an electric blower for generating suction force, and an electric blower drive means for changing the suction force of the electric blower. In the initial stage, an applied voltage is not applied to the motor, and the suction tool is moved back and forth. By detecting the operation by the counter electromotive voltage when reciprocating and applying a voltage to the motor and increasing the suction force of the electric blower, the suction force of the electric blower is also increased on the floor surface where the load on the carpet is heavy In addition, the floor surface is lightly loaded, such as wooden floors, but the suction force of the electric blower is also reduced to further reduce noise and blow off garbage. It is. Moreover, since it operate | moves by the suction force according to the floor surface, excess electric power can be suppressed.

  According to the third aspect of the present invention, the applied voltage of the motor is provided in a plurality of stages, the applied voltage is gradually varied depending on the state of the floor surface and the suction tool, and the motor is rotated at the minimum applied voltage that does not lock, so that the optimum according to the floor surface is achieved. It is possible to operate with various applied voltages, and to reduce noise and save energy on all floor surfaces.

  The fourth invention is provided with a rotation direction switching means for switching the rotation direction of the electric motor. Usually, the applied voltage is lowered and the electric motor is operated in the normal rotation direction, and the applied voltage of the electric motor becomes larger and exceeds the predetermined applied voltage. Then, by reversing the rotation direction of the motor in the reverse direction, it is important to operate on the floor with a light load, which is relatively easy to remove dust, so that the self-propelled performance is emphasized. On the floor with a heavy load on the carpet, By focusing on the lifting force by rotating in the opposite direction, the dust collection rate of the dust that has entered the carpet can be improved.

  The fifth aspect of the invention comprises a rotation direction switching means for switching the rotation direction of the electric motor, and normally the applied voltage is lowered to operate the electric motor in the reverse rotation direction, so that the applied voltage of the electric motor increases and becomes equal to or higher than the predetermined applied voltage. Then, by reversing the rotation direction of the motor to normal rotation, the operability on the carpet is heavy by optimizing the lifting force by operating in reverse rotation on a light floor surface with relatively light operability. Then, it is possible to improve the operability on the carpet by focusing on self-propelled performance by rotating in the forward direction.

  6th invention is equipped with the reciprocating detection means which detects the reciprocating motion of a suction tool, and changes the applied voltage of an electric motor when the suction tool is pushed forward and pulled back, and at the time of reciprocating motion Since it can be operated with an optimum applied voltage, further noise reduction and energy saving can be realized.

  In the seventh aspect of the invention, the applied voltage of the motor is low only in the initial stage, and gradually increases with the load, but does not become lower than the applied voltage that has once increased. When the operation stops for more than the set time, by performing the reset operation, the motor operates stably even if load fluctuations occur due to differences in the speed of the reciprocating operation of the suction tool or differences in the pressing force against the floor surface. Can be made.

  According to an eighth aspect of the present invention, there is provided a dust detection means for detecting the passage of dust in the dust collection path, the floor surface is determined based on an applied voltage for operating the electric motor, and the sensitivity of the dust detection means is changed to thereby detect the floor. It can be detected with dust detection sensitivity that matches the surface.

  9th invention is equipped with the operation switch which can operate the rotation direction of an electric motor, and can perform the cleaning suitable for the cleaning condition because a user can select a rotation direction.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a circuit block diagram of a vacuum cleaner according to the first embodiment of the present invention, and FIG. 2 is an external view of the vacuum cleaner.

  In FIG. 2, 1 is a main body of a vacuum cleaner, and 2 includes an electric blower for generating suction force and collecting dust in a dust collection chamber (not shown). Reference numeral 3 denotes a hose, which connects the hand operating unit 4 and the cleaner main body 1 for switching the operation mode of the electric vacuum cleaner that changes the strength of the suction force of the electric blower 2. Reference numeral 6 denotes a suction tool for sucking dust on the surface to be cleaned in contact with the floor surface, and has a built-in rotary brush 7 for scraping dust on the surface to be cleaned and an electric motor 8 for driving the rotary brush 7. The rotating brush 7 is driven by the electric motor 8 via a belt (not shown) or the like, or the electric motor 8 is built in the rotating brush 7 and the rotating brush is connected via a gear (not shown) or the like. 7 or the like. Reference numeral 5 denotes an extension pipe that communicates the suction tool 6 and the hose 4. By operating the hand operating unit 4 and driving the electric blower 2 and the electric motor 8, dust on the surface to be cleaned is scraped up from the suction tool 6, and the dust passes through the extension pipe 5 and the hose 3 to be used in the vacuum cleaner. While being transported to the main body 1, dust is collected in a dust collection chamber (not shown) built in the main body 1 of the vacuum cleaner, and the suction air is discharged from the main body 1 of the vacuum cleaner. A control circuit 9 that controls the operation of the electric blower 2 and the electric motor 8 in response to an operation from the hand operation unit 4 is built in the cleaner body 1.

  In FIG. 1, the vacuum cleaner of the present embodiment is divided into four blocks: a vacuum cleaner body 1, a hose 3 provided with a hand operation unit 4, an extension pipe 5, and a suction tool 6. 7 is an electric motor driving means for controlling the phase of the electric motor 8 that rotationally drives the electric motor 7. Reference numeral 11 denotes back electromotive force detection means. In this embodiment, the second DC power supply 12 of the control circuit 9 is connected to the motor driving means 10 via a resistor and connected to the motor 8. Moreover, in order to detect ON / OFF of the safety switch 13 built in the suction tool 6, both ends of the safety switch 13 are connected to the electric motor driving means 10 through resistors, and when locked, the phase is controlled. The lock is detected by changing the voltage due to the counter electromotive voltage of the OFF voltage. Reference numeral 14 denotes an electric blower driving means for phase-controlling the electric blower 2 that generates a suction force, and is connected in series with the electric blower 2. Reference numeral 15 denotes a microcomputer which is a control means for controlling the electric power supplied to the electric blower 2 and the electric motor 8, and takes in the switch operation information of the hand operation section 4 and the lock information from the lock detection means 11, and based on the information. The ignition pulse for phase control is output to the electric motor driving means 10 and the electric blower driving means 14 for control. Reference numeral 16 denotes a first DC power supply device for transmitting a signal from the hand operating unit 4 to the control circuit 11 and is constituted by a negative power supply with reference to the common line. The first DC power supply 16 is a negative power supply of 12 V or more in order to improve the reliability of the contact between the main body 1 and the hose 3. Reference numeral 12 denotes a second DC power supply device serving as a power source for the microcomputer 15, which is created by stepping down from the first DC power supply device 16, and is a negative power supply based on the common line. Reference numeral 17 denotes a commercial power source that supplies power to the vacuum cleaner.

  About the vacuum cleaner comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  As shown in FIG. 1, the hand operation unit 4 includes a plurality of switches SW1 to SW3 and resistors r1 to r4. The hand operation unit 4 is operated by changing the divided voltage with the resistor R built in the circuit on the main body 1 side. Is recognized, a signal is output from the microcomputer 15 to the electric motor driving means 10 and the electric blower driving means 14, and the electric blower 2 and the electric motor 8 are operated with a suction force corresponding to the hand operation. . The operation line of the electric motor 8 includes a safety switch 13 connected in series with the electric motor 8, and resistors r5 and r6 are built in before and after the safety switch 13 as shown in FIG. The microcomputer 15 recognizes whether the safety switch 13 is turned on or the electric motor 8 is rotated by the change in the divided voltage with the resistors R2 and R3, and controls the suction force of the electric blower 2. Here, in order to recognize the ON / OFF of the safety switch 13 and the rotation of the electric motor 8 and to reliably transmit the hand operation signal, the electric motor 8 has an OFF period of a certain time. This is because the hose 3 has a resistance component, and when a current is passed through the motor 8, a voltage drop occurs in the resistance component and the AC component is superimposed on the DC component, so that the hand operation is not normally transmitted. Because. At the same time, the situation of the suction tool 6 is recognized by the divided voltage during the OFF period. When the hand operation is performed, the microcomputer 15 transmits a signal to the motor driving means 10 so that the motor 8 operates with a small phase control signal, and the motor 8 operates with the phase-controlled voltage. Here, in the state of normal rotation, the voltage during the OFF period is V = 5 (V) * R2 / (combined resistance of R2 + R3 + r5 and r6) (for example, 2V) because there is a counter electromotive voltage. When 8 is locked by a load from the floor surface, V = 5 (V) * R2 / (R2 + R3) (for example, 2.8 V), and the voltage changes. FIG. 3 shows changes in the voltage waveform. When the microcomputer 15 recognizes this voltage change and detects lock, the phase value is changed so that the voltage becomes higher. When the load further increases and lock detection is performed, the phase value is gradually changed so that the voltage is further increased. In addition, since a heavy load can be recognized as a floor surface where dust such as carpets is difficult to collect dust, a signal is transmitted to the electric blower driving means 14 so that the suction force of the electric blower 2 is also increased. Perform the action. It is needless to say that this voltage change may be detected and controlled since it changes from the low timing of the commercial power supply 7 voltage when the rotational speed is reduced to some extent even if it is not completely locked. If the initial applied voltage of the electric motor 8 is 0 V, when not rotating, V = (5 (V) −electric motor built-in rectifying means VF) * R2 / (R2 + R3) (for example, 2.3 V) 6 is reciprocated to forcibly rotate with a load from the floor. Since a counter electromotive voltage is generated, V = 5 (V) * R2 / (R2 + R3 + r5 and r6 and combined resistance) (for example, 2 V) at the time of forward rotation, and V = 5 (V) * R2 / (R2 + R3) (for example, 2) at the time of reverse rotation. .8V), and by starting the rotation of the electric motor 8 only after detecting this, it is possible to suppress the wasteful power at the initial stage.

  Here, after a preset time has passed so that the applied voltage decreases when the load on the floor becomes lighter, check whether the phase is temporarily lowered and locked at regular intervals, and if it does not lock Thereafter, the operation is performed so that the phase is lowered, so that the operation can be performed with the applied voltage lowered when the load becomes light. However, when the applied voltage rises so that the power control of the motor 8 does not change frequently, the lock is detected and rises. However, the control is not performed on the lower side, and the operation of the motor 8 is performed on the floor surface. In order to change, it is also possible to easily reset the phase voltage once from the initial setting when the operation is stopped by raising the suction tool 6 or when a hand operation is performed.

  As described above, in the present embodiment, in the initial state, the motor 8 is rotated at 0 V or a small applied voltage, the counter electromotive voltage in the locked state is detected, and the applied voltage is gradually increased. Therefore, on a floor surface with a light load such as a wooden floor, the number of rotations can be suppressed, noise is reduced, and dust blowing is also reduced. Further, since the operation is performed with the applied voltage according to the floor surface, not only the excessive power is suppressed, but also the fluctuation of the power supply voltage can be automatically dealt with.

(Embodiment 2)
FIG. 4 is a circuit block diagram according to the second embodiment of the present invention.

  In FIG. 4, reference numeral 20 denotes a rotation direction switching means for switching the rotation direction of the electric motor 8, a rectifying means 21 for rectifying commercial power in the suction tool 6, a relay 22 for switching the current path of the electric motor 8, and a relay drive for driving the relay 22. The means 23 is constituted. The rectifying means 21, the relay, and 22 are connected between the safety switch 13 and the electric motor 8. Here, switching of the relay 22 is controlled by the microcomputer 15 of the main body 1, and the main body 1 to the suction tool 6 are connected for signal transmission. Other configurations are the same as those of the first embodiment, and the description thereof is omitted.

  About the vacuum cleaner comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  The electric blower 2 and the electric motor 8 are operated with a suction force corresponding to the hand operation by a signal from the hand operation unit 4. The rotation direction of the electric motor 8 normally rotates in the positive rotation direction, and light operability is realized by a self-propelled effect. When the electric motor 8 is locked by a load from the floor, the microcomputer 15 detects the lock and changes the phase value so that the voltage becomes higher. When the load is further increased and lock detection is performed, the phase value is gradually changed so as to further increase the voltage. However, when the phase value rises above a certain value, the microcomputer 15 transmits a switching signal to the relay 22, and the rotation direction of the electric motor 8 is reversed to reverse rotation. The reverse rotation eliminates the self-propelled effect and increases the scraping power. In other words, the phase increases because the floor surface is difficult for dust to collect, such as on heavy carpets, so that it reverses the direction of rotation and raises the lifting force to make it easier to collect dust. Increases dust collection efficiency.

  Also, it is normally rotating in the reverse rotation direction, and if it becomes difficult to operate due to heavy load, it should be cleaned with light operability if it becomes forward rotation and easy to operate. Can do. Further, if the user can select the rotation direction of the electric motor 8 with the hand operation unit 4, it can be selected according to the user's situation such as when the user wants to clean quickly or when the user wants to clean thoroughly. It becomes possible to perform cleaning according to the case of the user.

  As described above, in the present embodiment, the counter electromotive voltage in the locked state is detected, and the applied voltage is gradually increased. When the voltage exceeds the set applied voltage, the rotation direction of the motor 8 changes, Reversing the rotation increases the dust collection efficiency, and reversing it to the normal rotation realizes light operability. Further, if the user can select the rotation direction, it can be selected according to the situation of the user, and cleaning suitable for the user can be performed.

(Embodiment 3)
FIG. 5 is a simplified diagram showing the configuration of the reciprocating detection means 29 in the third embodiment of the present invention, and FIG. 6 is a circuit block diagram in the third embodiment of the present invention.

  As shown in FIG. 5, the reciprocating detection means 29 is provided in the suction tool 6, and disk electrodes 31 and 32 are disposed between the cylindrical electrodes 30 and the bottom portions at both ends thereof with insulators 34 and 35 interposed therebetween. And it has composition which has conductive ball 33 in the inside.

  As shown in FIG. 6, the circuit configuration is connected from the main body 1 to the suction tool 6 for signal transmission so that a signal from the reciprocation detecting means 29 is input to the microcomputer 15. Needless to say, a DC power source is constructed from a commercial power source for detecting the operation of the reciprocating detection means. Further, which of the disk-shaped electrodes 31 and 32 is in contact with the reciprocating detection means is detected by the divided voltage of the resistors r7 and r8 body resistor R4.

  About the vacuum cleaner comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  The electric blower 2 and the electric motor 8 are operated with a suction force corresponding to the hand operation by a signal from the hand operation unit 4. Here, when the suction tool 6 is pushed forward (hereinafter referred to as forward movement), the conductive ball 33 of the reciprocating detection means 29 moves to the extension tube 5 side by acceleration and contacts the disk-like electrode 32 on the extension tube 5 side. When the divided voltage of r8 and R4 is input to the microcomputer 15 and is pulled backward (hereinafter referred to as backward movement), the conductive ball 33 contacts the disk electrode 31, and the divided voltage of r7 and R4 is the microcomputer. By being input to 15, it can be detected whether the vehicle is moving forward or backward. As described in the first embodiment, the electric motor 8 operates to change the phase value and increase the torque of the electric motor 8 together with the lock detection as described in the first embodiment, but the lock detection is performed when the suction tool 6 moves forward. When the lock is detected during the forward movement, only the phase value during the forward movement is changed.When the lock is detected during the backward movement, only the phase value during the backward movement is changed. Operates to be variable.

  As described above, in this embodiment, the case is divided between forward movement and backward movement, and when lock is detected during forward movement, only the phase value during forward movement is changed, and the lock is applied during backward movement. By detecting only the phase value at the time of backward movement, it is possible to operate with the optimum applied voltage during the reciprocating operation, so that noise reduction and energy saving can be realized.

(Embodiment 4)
FIG. 7 is a circuit block diagram according to the fourth embodiment of the present invention. 40 is a dust detection means comprising a light emitting element and a light receiving element in the dust collecting path of dust, and the voltage of the light receiving element changes when dust passes and the light is blocked, and the passage of dust is detected. A signal from the dust detection means 40 is connected to be input to the microcomputer 15.

  About the vacuum cleaner comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  As the signal from the dust detection means 40, HI and LOW pulse signals are input to the microcomputer 15 as the dust passes. Here, on the floor surface where the applied voltage of the electric motor 8 is small and the load is small, dust such as a wooden floor is relatively easy to collect. Therefore, although dust detection is often performed at the initial stage of cleaning, the dust is collected immediately. The dust detection is stopped, and the notification means notifies the user that the dust is gone. However, since the applied voltage of the motor 8 is large and the floor surface has hair like a carpet, the hair of the carpet can be removed even if there is no dust. It operates to change the sensitivity of the dust detection means 40 by changing the count number of dust to notify that there is dust. This dust pulse count number is set by the applied voltage, and the larger the load, the larger the count number.

  As described above, in the present embodiment, since the sensitivity of the dust detection means 40 varies depending on the applied voltage of the electric motor 8, it can be detected with the dust detection sensitivity suitable for the floor surface.

  As described above, the vacuum cleaner according to the present invention, while satisfying the dust removal performance, reduces the number of rotations by operating the electric motor by lowering the applied voltage on a light floor such as a wooden floor, Noise is reduced, and dust blowing is also reduced. In addition, since it operates at an applied voltage according to the floor surface, it is possible to provide an environmentally friendly vacuum cleaner that can suppress excessive power.

The circuit block diagram of the vacuum cleaner which shows the 1st Embodiment of this invention External view of the vacuum cleaner (A) Commercial power supply waveform diagram of vacuum cleaner (b) Phase timing diagram of electric motor drive means of vacuum cleaner (c) Motor lock detection waveform diagram of vacuum cleaner The circuit block diagram of the vacuum cleaner which shows the 2nd Embodiment of this invention (A) Simplified view of reciprocating detection means showing the third embodiment of the present invention (b) Detailed conceptual view of reciprocating detection means (c) Same as above, Relationship between cylindrical electrode and disc-shaped electrode of reciprocating detection means Figure showing The circuit block diagram of the vacuum cleaner The circuit block diagram of the vacuum cleaner which shows the 4th Embodiment of this invention External view of conventional vacuum cleaner

Explanation of symbols

DESCRIPTION OF SYMBOLS 7 Rotating brush 8 Electric motor 10 Motor drive means 11 Back electromotive detection means 20 Rotation direction switching means 29 Reciprocation detection means 40 Dust detection means

Claims (9)

A rotating brush for scraping dust to the suction tool, an electric motor for rotating the rotating brush, an electric motor driving means for changing an applied voltage of the electric motor, and a counter electromotive force detecting means for detecting a counter electromotive voltage of the electric motor, When the load on the wood floor is small, the applied voltage is lowered to operate.When the load becomes heavy due to a load change on the carpet or the user pressing the suction tool against the floor, the applied voltage A vacuum cleaner characterized in that the electric motor is rotated by releasing the lock. A rotating brush for scraping dust to the suction tool, an electric motor for rotating the rotating brush, an electric motor driving means for changing an applied voltage of the electric motor, a counter electromotive detecting means for detecting a counter electromotive voltage of the rotating brush, An electric blower that generates a suction force and an electric blower drive means that varies the suction force of the electric blower. When the initial stage of operation is in a state where no applied voltage is applied to the motor and the suction tool is reciprocated back and forth A vacuum cleaner characterized by detecting that it has been operated by a back electromotive force voltage, applying a voltage to the electric motor and increasing the suction force of the electric blower. 3. The electric vacuum cleaner according to claim 1 or 2, wherein the applied voltage of the electric motor is provided in a plurality of stages, the applied voltage is gradually changed according to the state of the floor surface and the suction tool, and the electric motor is rotated at the minimum applied voltage that is not locked. . Rotation direction switching means for switching the rotation direction of the motor is provided.Normally, the applied voltage is lowered to operate the motor in the forward rotation direction, and when the applied voltage of the motor increases to a predetermined applied voltage or higher, the rotation direction of the motor is changed. The electric vacuum cleaner according to any one of claims 1 to 3, wherein the electric vacuum cleaner is reversely rotated. Rotation direction switching means for switching the rotation direction of the motor is provided.Normally, the applied voltage is lowered to operate the motor in the reverse rotation direction, and the rotation direction of the motor is changed when the applied voltage of the motor becomes larger than a predetermined applied voltage. The electric vacuum cleaner according to any one of claims 1 to 3, wherein the electric vacuum cleaner is reversed to forward rotation. 6. A reciprocating detection means for detecting a reciprocating motion of the suction tool, wherein the applied voltage of the electric motor is varied depending on whether the suction tool is pushed forward or pulled backward. A vacuum cleaner according to claim 1. The applied voltage of the motor is low only in the initial stage of operation, and gradually increases with the load, but it does not fall below the applied voltage that has once increased, and the operation of the motor such as switch operation or leaving the suction tool is again performed. The electric vacuum cleaner according to any one of claims 1 to 6, wherein a reset operation is performed when the operation is stopped for a set time or longer. 8. A dust detection means for detecting the passage of dust in the dust collection path is provided, the floor surface is judged based on an applied voltage for operating the electric motor, and the sensitivity of the dust detection means is changed. An electric vacuum cleaner according to any one of the above. The vacuum cleaner according to any one of claims 1 to 8, further comprising an operation switch capable of operating a rotation direction of the electric motor, wherein a user can select the rotation direction.

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