JP5166584B2 - Electric vacuum cleaner - Google Patents

Description

  The present invention relates to an electric vacuum cleaner in which an operating body having a suction port for sucking dust and dust is connected to a main body via a hose.

  In a vacuum cleaner in which the operating body is connected to the main body via a hose, when the user moves the operating body, the behavior of the main body follows the behavior of the operating body in such a manner that it is pulled through the hose. It becomes. For this reason, the behavior of the operating tool operated by the user is limited to the behavior of the main body, and the operating tool may not be moved as the user thinks, which causes a problem in terms of operability.

  On the other hand, for example, Patent Literature 1 describes a vacuum cleaner that includes a wheel that can rotate forward and backward and a motor that rotates the wheel, and assists the movement of the operation body by rotating the wheel by the motor. Has been.

JP-A-5-84174

  However, the vacuum cleaner configured as described above assists the movement of the operating body, and the configuration in which the behavior of the main body follows the behavior of the operating body in such a manner that the behavior of the main body is pulled through the hose is unchanged. Therefore, there are cases where the operating body cannot be moved as the user thinks, and there is room for further improvement in terms of operability.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vacuum cleaner that can appropriately follow the behavior of the main body and the operability of the main body. There is.

  The vacuum cleaner according to claim 1, comprising an operating body in which a suction port and a handle are integrated, a main body having a steering means for steering a direction, and a control means for controlling the steering means, In a vacuum cleaner in which an operating body is connected to the main body via a hose, one is provided on the operating body and the other is provided on the main body, and at least two air propagations between the operating body and the main body A transmission unit and a reception unit that form paths substantially parallel to each other in the left-right direction of the main body, and the operation body and the main body based on transmission / reception states of at least two aerial propagation signals from the transmission unit to the reception unit A distance detecting means for detecting the distance between the main body in the left-right direction of the main body and the moving direction of the operating body based on a distance difference between the two distances detected by the distance detecting means. An inclination detecting means for detecting a right / left inclination of the body, and when the inclination detected by the inclination detecting means is out of a predetermined range, the control means detects an inclination detected by the inclination detecting means thereafter. The driving of the steering means is controlled so as to be within a predetermined range, and a stop section for stopping the driving of the steering means is provided outside the predetermined range.

  According to the vacuum cleaner of the first aspect, the inclination of the main body in the left-right direction with respect to the moving direction of the operating body detected by the inclination detecting unit based on the distance difference between the two distances parallel to the left-right direction of the main body is predetermined. When outside the range, the control means controls the driving of the steering means so that the inclination detected by the inclination detecting means thereafter falls within the predetermined range, so the inclination of the main body in the horizontal direction with respect to the moving direction of the operating body is set. By always keeping within the predetermined range, the behavior of the main body can be appropriately followed by the behavior of the operating body, and the operability can be improved.

The functional block diagram which shows the reference embodiment of this invention and shows the electrical structure of a control circuit and its periphery Overall configuration of vacuum cleaner Functional block diagram showing distance measurement circuit and its surrounding electrical configuration The figure which shows the relationship between the transmission signal and the reception signal The figure which shows the relationship between the distance between an operating body and a main body, and the arrival time of an ultrasonic wave The figure which shows the relationship between the detected distance and the movement of the main body The whole block diagram of the vacuum cleaner which shows one embodiment of the present invention. Functional block diagram showing the electrical configuration of the control circuit and its periphery The figure which shows the inclination of the left-right direction of a main body with respect to the moving direction of an operation body The figure which shows the relationship between the detected inclination and the steering of a main body

(Reference embodiment)
Hereinafter, a reference embodiment of the present invention will be described with reference to FIGS.
FIG. 2 is a diagram schematically showing the overall configuration of the electric vacuum cleaner 1. The vacuum cleaner 1 is configured by connecting an operating body 2 to a main body 4 via a hose 3.

  The operating body 2 includes a head portion 5 and a handle 6. The head portion 5 is provided with a suction port 7 and is provided with auxiliary wheels, a rotating brush, and the like (none of which are shown). Further, a transmitter 8 (corresponding to a transmitting means) capable of transmitting ultrasonic waves is provided at a substantially central position on the rear side (the main body 4 side) of the head unit 5. The transmitter 8 is connected to a control circuit 14 (see FIG. 1) provided in the main body 4 through a pipe 9, a handle 6, and a hose 3. The head portion 5 is connected to the handle 6 via a pipe 9 so as to be rotatable and rotatable. Further, the handle 6 has a display unit 10 (corresponding to display means) provided with a plurality of LEDs, for example, and an operation panel (not shown) provided with various operation switches for controlling the operation of the vacuum cleaner 1. Etc. are provided.

  The main body 4 includes an electric blower and a dust collection chamber (both not shown). A receiver 11 (corresponding to receiving means) capable of receiving the ultrasonic waves transmitted from the transmitter 8 is provided on the front side (the operation body 2 side) of the main body 4. Two wheels 12 a and 12 b are arranged on the left and right sides of the main body 4 so as to be parallel to the left and right directions of the main body 4. An auxiliary wheel 13 is provided at the bottom of the main body 4.

  Next, the electrical configuration of the vacuum cleaner 1 will be described with reference to FIG. The control circuit 14 (corresponding to the control means) includes a distance measuring circuit 15 (corresponding to the distance detecting means), a microcomputer 16 and a motor drive circuit 17.

  The transmitter 8 and the receiver 11 are connected to the distance measuring circuit 15, and a transmission signal (pulse signal) is output to the transmitter 8 and a reception signal is input from the receiver 11. ing. In addition, a temperature sensor 18 is connected to the distance measuring circuit 15, and temperature information around the vacuum cleaner 1 is input as a temperature signal. The temperature sensor 18 is disposed, for example, at a predetermined part of the main body 4.

Here, the distance measuring circuit 15 will be described in detail with reference to FIG.
The distance measurement circuit 15 includes a pulse output circuit 19, a transmission amplifier 20, a time measurement circuit 21, a band pass filter (BPF) 22, a reception amplifier 23, and a distance calculation circuit 24.

  The pulse output circuit 19 is connected to the transmission amplifier 20 and the time measurement circuit 21, and outputs a transmission signal (see (a) in FIG. 4) to the transmission amplifier 20 at the same time (in synchronization with the output). The timing signal is output to the time measuring circuit 21. In this case, as a transmission signal, for example, a rectangular wave of 40 [kHz] is used, and about several tens [pulses] are applied at intervals of about several tens [msec]. The transmission amplifier 20 amplifies the transmission signal input from the pulse output circuit 19 and outputs it to the transmitter 8. The transmitter 8 transmits the transmission signal input from the transmission amplifier 20 as an ultrasonic wave.

The receiver 11 outputs the ultrasonic wave received from the transmitter 8 to the bandpass filter 22 as a reception signal (see (b) in FIG. 4). That is, an aerial propagation path is formed between the operating body 2 and the main body 4 by transmitting and receiving ultrasonic waves (corresponding to aerial propagation signals) from the transmitter 8 to the receiver 11. The band pass filter 22 extracts only the signal in the same band (40 [kHz] band) as the transmission signal from the reception signal input from the receiver 11 and outputs the signal to the reception amplifier 23. The reception amplifier 23 amplifies the reception signal input from the band pass filter 22 and outputs the amplified signal to the time measurement circuit 21.
The time measurement circuit 21 determines the difference between the time when the timing signal is input from the pulse output circuit 19 and the time when the reception signal is input from the reception amplifier 23 (until the ultrasonic wave transmitted from the transmitter 8 reaches the receiver 11). Time) as an arrival time signal to the distance calculation circuit 24.

The distance calculation circuit 24 is based on the arrival time signal input from the time measurement circuit 21 and the temperature signal input from the temperature sensor 18, and the distance between the operating body 2 and the main body 4 according to the expressions (1) and (2). Is calculated.
Speed of sound = 331.5 [m / s] + (0.6 [m / s] × temperature [° C.]) (1)
Distance between control body and main body = sound speed x arrival time of ultrasonic wave (2)
In this case, the distance between the operating body 2 and the main body 4 and the arrival time of the ultrasonic waves are substantially proportional as shown in FIG. Then, the distance calculation circuit 24 outputs the calculated distance to the microcomputer 16 as a distance signal.

  A motor drive circuit 17 is connected to the microcomputer 16 as shown in FIG. The microcomputer 16 is provided with a comparator (not shown). The first set distance and the second set distance (see FIG. 6) are stored in advance in a memory (not shown). The microcomputer 16 outputs the comparison result between the distance signal input from the distance measurement circuit 15 and the first set distance and the second set distance set in advance to the motor drive circuit 17 as a comparison signal. Further, the display unit 10 described above is connected to the microcomputer 16, and the number of lighting LEDs of the display unit 10 changes according to the comparison result.

  A motor 25 is connected to the motor drive circuit 17. The motor 25 has a rotating shaft 26 that rotates in the directions of arrows A1 and A2 in FIG. The rotary shaft 26 is connected to a shaft 27 to which the wheels 12a and 12b are connected via a gear mechanism 28. When the rotary shaft 26 is rotated in the directions of arrows A1 and A2 in FIG. , 12b are rotated in the direction of arrows B1 (forward direction of the main body 4) and B2 (reverse direction of the main body 4) in FIG.

  The motor drive circuit 17 controls the polarity of the drive signal output to the motor 25 (the direction in which the motor 25 is driven) based on the comparison signal input from the microcomputer 16. In this case, when the distance signal is larger than the first set distance, the polarity of the drive signal in the direction in which the main body 4 is advanced so that the distance detected by the distance measuring circuit 15 thereafter becomes the first set distance. To control. On the other hand, when the distance signal is smaller than the second set distance, the polarity of the drive signal is set in the direction in which the main body 4 is moved backward so that the distance detected by the distance measuring circuit 15 thereafter becomes the second set distance. Control. The motor drive circuit 17 is configured not to output a drive signal to the motor 25 when the distance signal is between the first set distance and the second set distance.

Next, the operation of the reference embodiment will be described with reference to FIG.
When the user moves the operating tool 2, the distance between the operating tool 2 and the main body 4 (the distance between the transmitter 8 and the receiver 11) varies. Then, the distance measurement circuit 15 detects the distance (distance signal) between the operating body 2 and the main body 4 based on the transmission / reception state of ultrasonic waves from the transmitter 8 to the receiver 11 (in this case, the length of arrival time). Is done.

  At this time, as shown in FIG. 6A, the control circuit 14 controls the polarity of the drive signal in the direction in which the main body 4 moves forward when the detected distance becomes larger than the first set distance. Then, the motor 25 is driven based on this drive signal, and the main body 4 is advanced toward the first set distance, so that when the main body 4 reaches the first set distance, the motor 25 is driven (the main body 4 Stop moving). On the other hand, when the detected distance becomes smaller than the second set distance, the polarity of the drive signal is controlled in the direction in which the main body 4 moves backward. Then, the motor 25 is driven based on this drive signal, and when the main body 4 reaches the second set distance by moving the main body 4 backward toward the second set distance, the motor 25 is driven (the main body 4 Stop moving). Further, when the detected distance is between the first set distance and the second set distance, that is, the main body 4 is within the range where the first set distance is one end and the second set distance is the other end. When within the predetermined range, the state where the driving of the motor 25 (movement of the main body 4) is stopped is maintained.

  As described above, according to the reference embodiment, the distance between the operating body 2 and the main body 4 detected by the distance measuring circuit 15 based on the transmission / reception state of the ultrasonic waves from the transmitter 8 to the receiver 11 is determined. When the distance is outside the predetermined range (becomes greater than the first set distance or less than the second set distance), the control circuit 14 subsequently determines that the distance detected by the distance measurement circuit 15 is the first distance. Since the driving of the motor 25 is controlled so as to be the set distance or the second set distance, the distance between the operating body 2 and the body 4 is maintained at the first set distance or the second set distance. 4 can be made to follow the behavior of the operating body 2 appropriately, and the operability can be improved.

  By the way, when the distance detected by the distance measuring circuit 15 is outside the above-described predetermined range, the distance detected by the distance measuring circuit 15 thereafter is not the first set distance or the second set distance, You may comprise so that the drive of the motor 25 may be controlled so that it may become any distance within the predetermined range between the 1st setting distance and the 2nd setting distance. Thereby, the distance between the operation body 2 and the main body 4 can be stabilized at any distance within a predetermined range.

In the vacuum cleaner 1 having the above-described configuration, the driving of the motor 25 may be controlled by giving hysteresis characteristics to the first set distance and the second set distance.
In this case, as shown in FIG. 6B, when the user moves the operating tool 2 from a state where the distance between the operating tool 2 and the main body 4 is within the predetermined range, Even if the distance between the main body 4 is out of the predetermined range, the control circuit 14 does not immediately start driving the motor 25, but the distance between the operation body 2 and the main body 4 is increased to a certain extent. After maintaining the state where the driving of the motor 25 is stopped until it becomes larger (smaller) than the set distance of 1 (second set distance), the driving of the motor 25 is started and the main body 4 moves forward (reverse). Even if the main body 4 moves forward (reverse) and the distance between the operating body 2 and the main body 4 becomes the first set distance (second set distance), the control circuit 14 immediately Rather than stopping the drive, the drive of the motor 25 is stopped after the main body 4 continues to advance (reverse) to some extent.

  By adopting a configuration in which the first set distance and the second set distance have hysteresis characteristics in this way, the distance between the operating body 2 and the main body 4 is set to the first set distance (second set distance). ), The driving and stopping of the motor 25 (moving and stopping the main body 4) can be prevented from being repeated unnecessarily, and stable running of the main body 4 can be realized.

Moreover, the structure which provides the stop area which stops the motor 25 in a part of the range larger than the 1st setting distance and the range smaller than the 2nd setting distance may be sufficient.
In this case, as shown in FIG. 6C, when the distance detected by the distance measuring circuit 15 is the stop section, the driving of the motor 25 (movement of the main body 4) is stopped. As a result, when the main body 4 is too far away from the operating body 2 or too close to the operating body 2, it is possible to prevent the main body 4 from running out of control, thereby improving safety. it can. When the user brings the operating tool 2 close to the main body 4 from the state where the main body 4 is stopped in the stop section, the distance between the operating tool 2 and the main body 4 is the first set distance (second set distance). ) And the main body 4 starts to move forward (reverse).

(One embodiment)
Next, an embodiment of the present invention will be described with reference to FIGS.
In the reference embodiment described above, the operation body 2 is configured to move the main body 4 to a distance within a predetermined range from the operation body 2. However, in this embodiment, the main body 4 is moved relative to the operation body 2. The thing of the structure which steers the main body 4 so that inclination may become inclination in a predetermined range is shown. Hereinafter, description of the same parts as those of the reference embodiment will be omitted, and only different parts will be described.

  As shown in FIG. 7, a transmitter 41 (corresponding to a transmission means) capable of transmitting ultrasonic waves is provided at a substantially central position on the rear side (main body 4 side) of the operating body 2 constituting the vacuum cleaner 40. ing. Receivers 42a and 42b (corresponding to receiving means) that can receive the ultrasonic waves transmitted from the transmitter 41 so as to be arranged in parallel in the left-right direction of the main body 4 on the front side (the operation body 2 side) of the main body 4. ) Is provided.

Next, the electrical configuration of one embodiment will be described with reference to FIG. Since the control circuit 43 (corresponding to the control means) is configured symmetrically when viewed from the moving direction of the main body 4, the components provided symmetrically will be shown in parentheses below.
The control circuit 43 includes a distance measuring circuit 44a (44b) corresponding to the distance detecting means, a microcomputer 45 (corresponding to the inclination detecting means), and a motor driving circuit 46a (46b).

  The distance measuring circuit 44a (44b) is configured similarly to the distance measuring circuit 15 (see FIG. 3) shown in the reference embodiment. In addition, the temperature sensor 18 is connected to the distance measuring circuit 44a (44b), and a temperature signal is input thereto. Then, the distance measuring circuit 44a (44b) calculates the distance between the operating body 2 and the left side (right side) of the main body 4 from the arrival time of the ultrasonic wave and the temperature around the vacuum cleaner 40, and the distance signal is a micro signal. Output to the computer 45.

  A motor drive circuit 46 a (46 b) is connected to the microcomputer 45. The first set angle and the second set angle (see FIG. 10) are stored in advance in a memory (not shown). The microcomputer 45 then tilts the main body 4 in the left-right direction with respect to the moving direction of the operating body 2 based on the difference (distance difference) between the distance signal input from the distance measurement circuit 44a and the distance signal input from the distance measurement circuit 44b. Is detected. Then, a result obtained by comparing the detected inclination with the first set angle and the second set angle set in advance is output as an angle signal to the motor drive circuit 46a (46b).

  A motor 47a (47b) is connected to the motor drive circuit 46a (46b). When a drive signal is given from the motor drive circuit 46a (46b), the motor 47a (47b) has wheels 12a (12b) via the rotating shaft 48a (48b), the gear mechanism 49a (49b), and the shaft 50a (50b). Are rotated in the direction of arrows C1 (forward direction of the main body 4) and C2 (reverse direction of the main body 4) in FIG. With such a configuration, a steering mechanism 51 (corresponding to a steering means) for steering the direction of the main body 4 is provided.

  The motor drive circuit 46a (46b) controls the polarity of the drive signal output to the motor 47a (47b) (the direction in which the motor 47a (47b) is driven) based on the angle signal input from the microcomputer 45. In this case, when the angle signal is larger than the first set angle, the polarity of the drive signal is controlled so that the inclination detected by the microcomputer 45 thereafter becomes the first set angle. On the other hand, when the angle signal is smaller than the second set angle, the polarity of the drive signal is controlled so that the inclination detected by the microcomputer 45 thereafter becomes the second set angle. Further, when the angle signal is between the first set angle and the second set angle, the drive signal is not output to the motor 47a (47b).

Next, the operation of the embodiment will be described with reference to FIGS. 9 and 10. Since the main body 4 is configured to be bilaterally symmetric as viewed from the moving direction of the main body 4 as described above, the description of the action on the right side of the main body 4 is omitted here, and only the action on the left side of the main body 4 is described. explain.
When the user moves the operating tool 2, the inclination of the main body 4 in the left-right direction with respect to the moving direction of the operating tool 2 varies. Then, the microcomputer 45 detects the inclination of the main body 4 in the left-right direction with respect to the moving direction of the operating body 2 based on the distance difference between the two distances parallel to the left-right direction of the main body 4.

  At this time, as shown in FIG. 10A, when the detected inclination becomes larger than the first set angle, the control circuit 43 sets the polarity of the drive signal in the direction in which the left side of the main body 4 advances (FIG. 9 ( a) Control is performed in the direction of arrow D with the middle fulcrum P (the contact point of the wheel 12b) as the center. Then, the motor 47a is driven based on this drive signal, and the direction of the main body 4 is steered clockwise (see arrow E in FIG. 9A), so that the inclination of the main body 4 reaches the first set angle. Then, the driving of the motor 47a (steering in the direction of the main body 4) is stopped. On the other hand, when the detected inclination becomes smaller than the second set angle, the polarity of the drive signal is controlled in the direction in which the left side of the main body 4 moves backward (the direction of arrow F centering on the fulcrum P in FIG. 9B). Then, the motor 47a is driven based on this drive signal, and the direction of the main body 4 is steered counterclockwise (see arrow G in FIG. 9A), so that the inclination of the main body 4 reaches the second set angle. Then, the driving of the motor 47a (steering in the direction of the main body 4) is stopped. When the detected distance is between the first set angle and the second set angle, that is, the inclination of the main body 4 has the first set angle as one end and the second set angle as the other end. When it is within the range (within the predetermined range), the state where the driving of the motor 47a (steering in the direction of the main body 4) is stopped is maintained.

  As described above, according to one embodiment, the horizontal direction of the main body 4 with respect to the moving direction of the operating body 2 detected by the microcomputer 45 based on the distance difference between the two distances parallel to the horizontal direction of the main body 4 is described. When the inclination is out of the predetermined range (becomes larger than the first set angle or smaller than the second set angle), the control circuit 43 causes the inclination detected by the microcomputer 45 thereafter to be the first set angle. Since the driving of the steering mechanism 51 is controlled so as to be the set angle or the second set angle, the inclination in the left-right direction of the main body 4 with respect to the moving direction of the operating body 2 is set to the first set angle or the second set angle. By maintaining, the behavior of the main body 4 can appropriately follow the behavior of the operating body 2, and the operability can be improved.

  When the detected inclination is larger than the first set angle (see FIG. 9A), the direction of the main body 4 may be steered by moving the right side of the main body 4 backward. . Further, when the detected tilt is smaller than the second set angle (see FIG. 9B), the direction of the main body 4 may be steered by moving the right side of the main body 4 forward. . Further, the left side of the main body 4 and the right side of the main body 4 may be steered in opposite directions (forward direction and reverse direction).

  Also in this case, when the inclination detected by the microcomputer 45 is outside the above-described predetermined range, the inclination detected by the microcomputer 45 thereafter is the first set angle or the second set angle. Instead, the drive of the motor 47a (47b) may be controlled so as to have any inclination within a predetermined range between the first set angle and the second set angle. Thereby, the inclination of the main body 4 can be stabilized at any inclination within the predetermined range.

  Further, as shown in FIG. 10B, the driving of the motor 47a (47b) may be controlled by giving hysteresis characteristics to the first set angle and the second set angle. According to such a configuration, even if the inclination of the main body 4 repeatedly fluctuates before and after the first set angle (second set angle), the motor 47a (47b) is driven and stopped (the main body 4 is steered and The stop) can be prevented from being repeated unnecessarily, and stable running of the main body 4 can be realized.

  In addition, as shown in FIG. 10C, a stop section for stopping the motor 47a (47b) is provided in a part of the range larger than the first set angle and the range smaller than the second set angle. May be. According to such a configuration, when the main body 4 is too far away from the operation body 2 or too close to the operation body 2, it is possible to prevent the main body 4 from running out of control in advance. Improvements can be made. In this case as well, when the user brings the direction of the operating tool 2 close to the direction of the main body 4 from the state where the main body 4 is stopped in the stop section, the inclination of the main body 4 in the left-right direction with respect to the moving direction of the operating tool 2 is increased. Approaching the first set angle (second set angle), the forward movement (reverse) of the main body 4 is started.

(Other embodiments)
In addition, this invention is not limited to each above-mentioned embodiment, It can deform | transform or expand as follows.

  The reference embodiment may be combined with one embodiment, that is, the motor is controlled so that the distance between the operating body 2 and the main body 4 is within a predetermined range, and the main body with respect to the moving direction of the operating body 2 The steering means may be controlled so that the inclination in the left-right direction of 4 is within a predetermined range.

The first setting distance (angle) and the second setting distance (angle) may be set by the user.
The transmission unit may be provided in the main body 4 and the reception unit may be provided in the operation body 2. Further, the air propagation signal is not limited to the ultrasonic wave, and may be, for example, an infrared ray or a laser.

  In the drawings, 1 and 40 are vacuum cleaners, 2 is an operating body, 3 is a hose, 4 is a main body, 6 is a handle, 7 is a suction port, 8 and 41 are transmitters (transmission means), and 10 is a display unit (display) Means), 11, 42a, 42b are receivers (reception means), 12a, 12b are wheels, 14, 43 are control circuits (control means), 15, 44a, 44b are distance measurement circuits (distance detection means), 25, Reference numerals 47a and 47b denote motors, 45 denotes a microcomputer (tilt detection means), and 51 denotes a steering mechanism (steering means).

Claims (3)

An operating body in which a suction port and a handle are integrated, and a main body having a steering means for steering the direction and a control means for controlling the steering means, and the operating body is connected to the main body via a hose. In the vacuum cleaner that has been
A transmission unit configured to form at least two aerial propagation paths between the operating body and the main body so as to be parallel to each other in the left-right direction of the main body. Receiving means;
A distance detecting means for detecting a distance between the operating body and the main body in the left-right direction of the main body based on a transmission / reception state of at least two aerial propagation signals from the transmitting means to the receiving means;
Inclination detecting means for detecting the inclination of the main body in the left-right direction with respect to the moving direction of the operating body based on a difference between two distances detected by the distance detecting means;
The control means controls the driving of the steering means so that the inclination detected by the inclination detection means thereafter falls within the predetermined range when the inclination detected by the inclination detection means is outside the predetermined range. In addition, the electric vacuum cleaner characterized in that a stop section for stopping the driving of the steering means is provided outside the predetermined range. The steering means includes at least two wheels arranged in parallel in the left-right direction of the main body, and at least two motors that rotate the at least two wheels.
The electric vacuum cleaner according to claim 1, wherein the control means controls the driving of the at least two motors independently. The transmission means is composed of one transmitter arranged at a substantially central position of one of the operating body and the main body,
The receiving means is composed of two receivers arranged in parallel in the left-right direction of the other of the operating body and the main body,
When the transmitter and one of the two receivers form one air propagation path, the transmitter and the other receiver of the two receivers transmit the other air propagation substantially simultaneously. The electric vacuum cleaner according to claim 1, wherein a path is formed.

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