CN102292012A - Electric vacuum cleaner - Google Patents

Abstract

Disclosed is an electric vacuum cleaner that is capable of accurately determining that sparks are being emitted within an electric blower, and preventing smoke or fire from being emitted by the electric blower. An electric vacuum cleaner (1) comprises a spark detection means (31), which detects that a spark is arising due to friction between a commutator (23) of an electric blower (10) that creates a negative pressure upon a dust chamber (7), and a carbon brush (26), and a control means (32), which controls the electric blower (10) based on a spark detection information from the spark detection means (31), wherein the spark detection means (31) derives a difference between a previous sampled value and a current sampled value, predicts a successive value from the difference thus derived, and interrupts, by way of the control means (32), the operation of the electric blower (10); if the difference between the predicted value and the measured value is greater than a predetermined value.

Description

electric vacuum cleaner

technical field

The present invention relates to an electric vacuum cleaner having a spark detector that detects sparks caused by friction between a commutator and carbon brushes of an electric blower.

Background technique

Conventionally, electric vacuum cleaners have been proposed in which, in order to prevent smoke and fire from being generated in the electric blower, a spark caused by friction between a rectifier and a carbon brush of the electric blower is detected by a spark detector to control the electric blower ( For example, see Patent Documents 1 and 2).

The electric vacuum cleaner according to Patent Document 1 uses a spark detector that obtains recent data and previous data of digital values sampled by an A/D converter, and when the calculated difference is greater than a preset predetermined spark determination level Determine spark failure. In addition, the spark detector calculates a difference between the maximum value and the minimum value within a predetermined period, and determines a spark failure when the calculated difference is greater than a preset predetermined spark determination level.

Furthermore, the electric vacuum cleaner according to Patent Document 2 has a photodetector that detects sparks caused by friction between the commutator and carbon brushes of the electric blower. An electric blower error is detected to stop the electric blower in response to detection of the spark by the light detector.

However, the electric vacuum cleaner according to Patent Document 1 obtains recent data and previous data of digital values sampled by the A/D converter, and determines spark failure when the calculated difference is greater than a preset predetermined spark determination level. In this case, false detection may occur if the preset predetermined spark determination level is incorrect or does not have a tolerance. In addition, the electric vacuum cleaner calculates a difference between the maximum value and the minimum value within a predetermined period, and determines a spark failure when the calculated difference is greater than a preset predetermined spark determination level. In this case, noise may be detected, resulting in false detection, which may degrade reliability.

Furthermore, the electric vacuum cleaner according to Patent Document 1 does not consider subsequent control after an error is detected and the electric blower is stopped, and is not easy to use.

The electric vacuum cleaner according to Patent Document 1 obtains recent data and previous data of digital values sampled by the A/D converter, and determines a spark failure when the calculated difference is greater than a preset predetermined spark determination level. Typically, when an electric blower is activated, the rate of spark generation is high and then that rate tends to decrease. Spark detectors and electric blowers lack controls to account for this tendency. Furthermore, if the predetermined value is only one and is set based on sparks generated when a certain period of time has elapsed and the electric blower has been operating stably, the high spark generation rate at the time of activation may exceed the predetermined value and the normally operating electric blower may was inconveniently stopped.

Furthermore, the photodetector of the electric vacuum cleaner according to Patent Document 2 lacks stability and reliability of photodetection in the case where sparks generating a large amount of light decrease over time.

Patent Document 1: Japanese Patent Laid-Open No. 2008-86124

Patent Document 2: Japanese Patent Laid-Open No. 2006-204470

Contents of the invention

An object of the present invention is to provide an electric vacuum cleaner that detects sparks caused by friction between a commutator of an electric blower and carbon brushes and stops the operation of the electric blower to prevent generation of smoke and fire in the electric blower.

Another object of the present invention is to provide an electric vacuum cleaner without false detection to ensure reliable and stable false detection; not only to detect sparks caused by friction between the rectifier and carbon brushes in the electric blower and to stop the operation of said electric blower operation, and after cessation of operation, activates a control device to control the electric blower to prevent smoke and fire from being generated in the electric blower; and is easy to use.

Another object of the present invention is to provide an electric vacuum cleaner without stopping the normal operation of the electric blower, detect sparks caused by friction between the rectifier and the carbon brush in the electric blower and stop the operation of the electric blower to prevent smoke and fire in the electric blower described above; and has excellent reliability.

In order to achieve the above objects, an electric vacuum cleaner according to the present invention includes: a dust collection chamber provided in the vacuum cleaner main body; an electric blower causing suction negative pressure to act on the dust collection chamber a spark detector that detects a spark caused by friction between a rectifier and a carbon brush of the electric blower; and a control unit that controls the spark detector based on spark detection information from the spark detector The electric blower, wherein the spark detector calculates a difference between a previous value and a recent value of a sampled value; estimates a next value based on the difference; and when the difference between the estimated value and the measured value The control unit stops the operation of the electric blower when the absolute value is greater than a predetermined value.

The spark detector calculates a difference between a previous value and a recent value of the sampled value; estimates a next value based on the difference; and when the difference between the estimated value and the measured value is greater than a predetermined value, determines A spark was created. When the spark detector determines that a spark is generated, the control unit stops the operation of the electric blower, and does not reactivate the electric blower after the stop.

Further, when the spark detector determines that a spark is generated, the control unit stops the operation of the electric blower, and enables the operation of the electric blower until the number of stops reaches a predetermined number of times.

Also, a plurality of predetermined values are set. In a period from activation of the electric blower until a predetermined time, a first predetermined value is set, and after the predetermined time elapses, a predetermined value lower than the first predetermined value is set.

Description of drawings

Fig. 1 is the schematic diagram of the electric vacuum cleaner of the first embodiment of the present invention;

2 is a partially cut side view of an electric blower used in the electric vacuum cleaner of the first embodiment of the present invention;

3 is a block diagram of a control circuit for an electric blower in the electric vacuum cleaner of the first embodiment of the present invention;

4 is a control flow diagram of a first example of spark detection and control for the electric vacuum cleaner of the first embodiment of the present invention;

5 is a schematic diagram of a sampling method used in spark detection in the first example of spark detection and control of the electric vacuum cleaner of the first embodiment of the present invention;

6 is a control flow diagram of a second example of spark detection and control for the electric vacuum cleaner of the first embodiment of the present invention;

7 is a schematic diagram of a sampling method used in spark detection in a second example of spark detection and control of the electric vacuum cleaner of the first embodiment of the present invention;

FIG. 8 is a control flow diagram of a third example of spark detection and control for the electric vacuum cleaner of the first embodiment of the present invention;

9 is a schematic diagram of a sampling method used in spark detection in a third example of spark detection and control of the electric vacuum cleaner of the first embodiment of the present invention;

10 is a table showing differences in integrated value (integrated value) depending on power supply voltage, frequency, and operation mode in the spark detection of the electric vacuum cleaner of the first embodiment of the present invention;

11 is a graph showing the relationship between the power supply voltage and the integral value in the strong mode at 50 Hz in the spark detection of the electric vacuum cleaner according to the first embodiment of the present invention;

12 is a graph showing the relationship between the power supply voltage and the integral value in the middle mode at 50 Hz in the spark detection of the electric vacuum cleaner according to the first embodiment of the present invention;

13 is a graph showing the relationship between the power supply voltage and the integral value in the strong mode at 60 Hz in the spark detection of the electric vacuum cleaner according to the first embodiment of the present invention;

Fig. 14 is a relation table between the power supply voltage (detection voltage) and the predetermined value at the rated power supply voltage of 100V in the spark detection of the electric vacuum cleaner according to the first embodiment of the present invention;

15 is a block diagram of a control circuit for an electric blower in an electric vacuum cleaner according to a second embodiment of the present invention;

16 is a control flow diagram of a first example of spark detection and control for the electric vacuum cleaner of the second embodiment of the present invention;

17 is a control flow diagram of a second example of spark detection and control for the electric vacuum cleaner of the second embodiment of the present invention;

18 is a control flow diagram of a third example of spark detection and control for the electric vacuum cleaner of the second embodiment of the present invention;

Fig. 19 is a control flowchart of the spark detection and control of the electric vacuum cleaner according to the third embodiment of the present invention;

20 is a graph showing the relationship between the operation time and the amount of spark after activation of the electric blower used in the electric vacuum cleaner according to the third embodiment of the present invention;

Fig. 21 is a table showing the relationship between power supply voltage levels and set values used in the electric vacuum cleaner of the third embodiment of the present invention.

symbol description

1 electric vacuum cleaner

2 vacuum cleaner body

6 suction accessories

7 dust collection chamber

10 electric blower

14 motor part

15 motor housing

16 stator

17 rotors

18 brush mechanism

20 motor

23 rectifier

24 brush bracket fixing part

25 brush holder

26 carbon brushes

30 Control circuit for electric blower

31 spark detector

32 control units

33 power adjustment part

34 supply voltage detector

Detailed ways

"Electric vacuum cleaner according to the first embodiment"

An electric vacuum cleaner according to a first embodiment of the present invention will be described with reference to the drawings.

As illustrated in FIG. 1 , an electric vacuum cleaner 1 according to a first embodiment of the present invention includes: a vacuum cleaner main body 2; A horse connection (horse connection) port 2a in the front part of the front part; an extension pipe 5, which is connected to a manually operated conduit 4 provided at the other end of the dust collection hose 3 in a detachable and detachable manner; and a floor suction fitting 6, It is connected to the front end of the extension pipe 5 in an attachable and detachable manner.

The vacuum cleaner main body 2 internally includes a first dust separator and a second dust separator, which are communicatively connected to the dust collection hose 3 and are not shown. The vacuum cleaner main body 2 includes a dust collection chamber 7 having: a dust collector as a first dust separator employing a high-speed separation system that separates dust contained in a high-speed air flow by gravity difference; and A pleat filter as a second dust separator, and the main body 2 also includes an electric blower 10 that makes suction negative pressure act on the dust collection chamber 7 .

As illustrated in FIG. 2 , the electric blower 10 includes a centrifugal blower portion 12 having a suction port 11 ; and a motor portion 14 having a discharge port 13 .

The motor portion 14 includes: a motor housing 15 having an exhaust port 13; a stator 16 provided on an inner peripheral surface 15a of the motor housing 15; a rotor 17 rotatably supported inside the motor housing 15; and a pair of brush mechanisms 18, It is provided in the motor housing 15 and is electrically connected to the rotor 17 . The stator 16 , the rotor 17 , and the pair of brush mechanisms 18 constitute a motor 20 .

The rotor 17 is provided inside the stator 16 . The rotor 17 includes: a rotor shaft 21 disposed at the center of the shaft; a field coil 22 (rotor coil) wound around the rotor shaft 21; and a rectifier 23 electrically connected to the field coil 22 and disposed on the rotor shaft 21.

The brush mechanism 18 includes: a brush holder 25 passing through a brush holder fixing portion 24; a carbon brush 26 slidably accommodated in the brush holder 25;

As illustrated in FIG. 3 , the control circuit 30 for the electric blower includes: the electric blower 20 , a spark detector 31 , a control unit 32 , a power regulating part 33 , and a power supply voltage detector 34 .

As the spark detector 31, a current transformer that detects the electric current of the electric blower 20 is used. The current detected by the current transformer is converted into a voltage value. As the power supply, for example, a commercial power supply with a rating of 100V is used.

When a spark is generated in the brush mechanism 57, the current value tends to decrease.

The control unit 32 includes a microcomputer and a memory. As the power adjustment section 33, for example, a triac is used.

The spark detector 31 detects the current flowing through the electric blower 20 . Based on the spark detection information, the control circuit 30 controls the electric blower 20 through the control unit 32 and the power adjustment part 33 .

The power supply voltage detector 34 detects the power supply voltage, and inputs the power supply voltage information to the control unit 32 .

Next, spark detection and control for the electric blower in the electric vacuum cleaner according to the first embodiment will be described.

(first example of spark detection and control)

Based on FIGS. 4 and 5 , a first example of spark detection and control will be described.

Use the electric vacuum cleaner 1 and turn on the electric blower 10 (S1).

Multiple samples are taken at equal time intervals. For example, sampling is performed at 100 points at a sampling interval of 10 ms at a half frequency of 50 Hz. When phase control is performed, sampling is performed only while current is flowing.

For example, the spark detector 31 detects the current flowing through the electric blower 10, and converts the current into a voltage (S2).

The voltage value is stored in the control unit 32 as the previously measured value Ia of the sample (n-2) (S3).

Furthermore, spark detector 31 detects the current flowing through electric blower 10, converts the current into a voltage, and stores the voltage value in control unit 32 as the latest measured value Ib of sample (n−1).

The control unit 32 calculates an estimated value Ine (S5).

The estimated value Ine is estimated from the previous measured value Ia and the latest measured value Ib, and more specifically, the difference between the previous measured value Ia and the latest measured value Ib is added to the latest measured value Ib.

That is Ine=Ib+(Ib-Ia)

The control unit 32 determines whether the absolute value of the difference between the estimated value Ine and the measured value In is larger than a predetermined value Is (S6).

That is, the control unit 32 determines whether |In-Ine|>Is is satisfied.

The current value of sample n is used as measured value In. The predetermined value Is is calculated in advance through experiments in a state where the carbon brush 26 is normal.

When the absolute value of the difference between estimated value Ine and measured value In is larger than predetermined value Is (YES in S6), control circuit 30 stops electric blower 10 via control unit 32 and power adjustment section 33 (S7).

A state where the absolute value of the difference between the estimated value Ine and the measured value In is larger than the predetermined value Is indicates that sparks are generated by friction between the commutator 23 and the carbon brush 26 in the electric blower 10 . Thus, the control circuit 30 stops the electric blower 10 to prevent generation of smoke and fire in the electric blower 10 .

When it is determined in S6 that the absolute value of the difference between the estimated value Ine and the measured value In is not greater than the predetermined value Is (NO in S6), the process returns to S2, where subsequent processes are repeated in the same manner.

A state where the absolute value of the difference between estimated value Ine and measured value In is not greater than predetermined value Is indicates that no spark is generated by friction between commutator 23 and carbon brush 26 in electric blower 10 . Thus, control circuit 30 allows electric blower 10 to continue to operate.

A first example of current spark detection and control determines whether a spark has occurred by: obtaining the difference between the previous value and the most recent value of the sampled measured value to estimate the next value; and when the difference between the estimated value and the next measured value When the absolute value of the difference between them is greater than a predetermined value, the operation of the electric blower is stopped. Thus, unlike conventional methods, there is no false detection, and precisely, the first paradigm of current spark detection and control detects sparks caused by friction between the rectifier and carbon brushes, safely stops the operation of the electric blower, and prevents Smoke and fire in electric blower.

(Second example of spark detection and control)

Based on FIGS. 6 and 7 , a second example of spark detection and control will be described.

The same steps as S1 to S5 of the first example illustrated in FIG. 4 are performed by repeating a plurality of n-2 times at the same half frequency ( S11 to S15 ).

The detecting step is repeated a plurality of n-2 times, and the control unit 32 determines whether the integrated absolute value of the difference between the measured value In ₁ and the estimated value In ₁ is larger than a predetermined value Is (S16).

That is, the control unit 32 determines whether |In ₁ −Ine ₁ |>Is is satisfied.

When the absolute value of the sum of the differences between the measured value In ₁ and the estimated value In ₁ is larger than the predetermined value Is ("Yes" in S16), the control circuit 30 stops the electric blower 10 through the control unit 32 and the power adjustment part 33 ( S17).

A second example of current spark detection and control determines whether a spark has occurred by repeating the detection step a number of n-2 times; and integrating the absolute value of the difference between the measured and estimated values, allowing the measured and estimates are unchanged and stable. Thus, unlike the conventional method, there is no false detection and can be more precise, the second paradigm of the current spark detection and control detects the spark caused by the friction between the rectifier and the carbon brush, safely stops the operation of the electric blower, and Prevent smoke and fire in electric blowers.

(Third example of spark detection and control)

Based on FIGS. 8 and 9 , a third example of spark detection and control will be described.

The same steps ( S21 to S25 ) as S11 to S15 of the second example illustrated in FIG. 6 are performed by repeating a plurality of N times at the same frequency (S).

The detection step is repeated a plurality of n-2 times, and the absolute value of the difference between the measured value In ₂ and the estimated value In ₂ is integrated, and the integrated value is stored.

In addition, as shown in FIG. 9, in the next cycle (S+1), for example, the detection step is repeated a plurality of n-2 times at the same stage, and further in the cycle (S+Nn), the detection The steps are repeated a number of (S+Nn) times.

The integrated value of the obtained absolute value of the difference between the measured value In ₂ and the estimated value In ₂ is averaged (n times) for each frequency of the power supply to determine whether the average value is greater than a predetermined value Is (S26).

Subsequently, in the same manner as S6 of the first example illustrated in FIG. 4 , when "YES", the process moves to S27; when "NO", the process returns to S22.

A third example _of current spark detection and control determines whether a spark is generated in the following manner: in multiple cycles, the detection step is repeated _multiple times; The integral values of the absolute values of the differences are averaged (n times), allowing to remove outliers and use constant and stable integral values. Thus, unlike the conventional method, there is no false detection and can be more precise, the third paradigm of the current spark detection and control detects the spark caused by the friction between the rectifier and the carbon brush, safely stops the operation of the electric blower, and Prevent smoke and fire in electric blowers.

(Fourth example of spark detection and control)

The fourth example of current spark detection and control changes the predetermined value according to the power supply voltage value in the first to third examples.

As exemplified in Fig. 10 "(a) Operation Mode (Strong) and (b) Operation Mode (Middle)" to Fig. 13, as each power supply voltage of 50 Hz and 60 Hz increases, the integral value also increases. It should be understood that for any supply voltage of 50Hz and 60Hz, the integrated value at 60Hz is greater than the integrated value at 50Hz.

As can be understood from FIGS. 10( a ) and ( b ), FIG. 11 , and FIG. 12 , at 50 Hz, the integrated value varies according to the strong mode and the medium mode.

Therefore, it is necessary to change the predetermined value according to changes in the power supply voltage and frequency.

For example, the power supply voltage detector 34 illustrated in FIG. 3 detects the power supply voltage and the power supply voltage information is input to the control unit 32, and the control unit 32 rewrites a predetermined value previously stored in the memory.

When the power supply voltage is rated at 100V, the relationship between the power supply voltage (detection voltage) and the predetermined value is exemplified in FIG. 14 .

As illustrated in FIG. 14 , for each level of the power supply voltage, a predetermined value is determined. For example, for voltage<80V, the predetermined value is A; for 80V≤voltage≤90V, the predetermined value is B; for 90V≤voltage≤100V, the predetermined value is C; and for 100V≤voltage, the predetermined value is D. Thus, the predetermined value is rewritten every 10V.

The fourth example of current spark detection and control determines whether a spark is generated by changing a predetermined value according to a power supply voltage value in addition to the detection steps in the first to third examples of spark detection and control. Thus, unlike the conventional method, there will be no false detection, depending on the power supply voltage, the fourth paradigm of the current spark detection and control accurately detects the spark caused by the friction between the rectifier and the carbon brush, safely stops the operation of the electric blower, And prevent the generation of smoke and fire in the electric blower.

Thus, the electric vacuum cleaner according to the first embodiment of the present invention detects sparks caused by friction between the commutator and carbon brushes of the electric blower, stops the operation of the motor, and prevents smoke and fire from being generated in the electric blower.

"Electric vacuum cleaner according to the second embodiment"

Now, an electric vacuum cleaner according to a second embodiment of the present invention will be described.

The electric vacuum cleaner according to the second embodiment not only has the same configuration as the electric vacuum cleaner according to the first embodiment, but also has a notification unit 35 connected to a control unit 32 as exemplified in FIG. 15 .

Spark detection and control by means of a control circuit of an electric vacuum cleaner according to a second embodiment will be described.

(first example of spark detection and control)

Steps S31 to S36 in the flowchart of the second example of current spark detection and control illustrated in FIG. 16 are the same as steps S1 to S6 in the first example of the electric vacuum cleaner according to the first embodiment illustrated in FIG. 4 , And thus its description will be omitted.

When the absolute value of the difference between the estimated value Ine and the measured value In is larger than the predetermined value Is, it indicates that sparks are generated by friction between the commutator 23 and the carbon brush 26 of the electric blower 10 . Thus, the control unit 32 stops the electric blower 10 to prevent generation of smoke and fire in the electric blower 10 . At this time, the notification unit 35 notifies that the spark is generated and the electric blower 10 is stopped (S37).

The stop information of the electric blower 10 is stored in the memory of the control unit 32 (S38).

While and after the memory of the control unit 32 stores the stop information, subsequent operation requests from the control switch 4a will be ignored to prevent the electric blower 10 from operating (S39).

In addition, when the power supply of the memory is cut off to stop the power supply to the electric vacuum cleaner, the memory holds the stop information therein; and when the power plug is inserted again to supply power to the electric vacuum cleaner 1, the operation request from the control switch 4a is ignored, To prevent the electric blower 10 from operating.

A first example of spark detection and control determines whether a spark has occurred by obtaining the difference between the previous value and the most recent value of the sampled measured value to estimate the next value; When the difference between is greater than a predetermined value, the operation of the electric blower is stopped. In addition, after the operation is stopped, the control device is activated to store stop information in the memory, and subsequent operation requests from outside such as control switches are ignored to prevent the operation of the electric blower and prevent generation of smoke and fire in the electric blower .

(Second example of spark detection and control)

The second example of pre-spark detection and control is different from the first example in that when it is determined that a spark has been generated, the operation of the electric blower is stopped, and the operation of the electric blower is prevented while and after the operation is stopped, whereas in the first example In the second example, when and after the number of operation stops reaches a predetermined number of times, the subsequent operation of the electric blower is stopped.

By referring to Fig. 17, a second example of current detection and control will be described.

Steps S41 to S46 are the same as steps S1 to S6 in the first example of the electric vacuum cleaner according to the first embodiment illustrated in FIG. 4 , and thus description thereof will be omitted.

In S47 , spark generation is detected and the operation of the electric blower 10 is stopped by the control unit 32 and the power adjustment portion 33 . Then, when the operation of the electric blower 10 is stopped, the first stop is stored in the memory of the control unit 32 . When the spark generation is eliminated, the operation of the electric blower 10 is resumed. When spark generation is detected again, the number of stops is increased by 1 (S48).

The control unit 32 determines whether the number of stops reaches a predetermined number of times (S49).

When the number of stops reaches the predetermined number ("YES"), the memory of the control unit 32 stores the number of stops (S50).

Subsequently, the operation request from the control switch 4a will be ignored, and the operation of the electric blower 10 will be prevented (S51).

When it is determined in S49 that the number of stops has not reached the predetermined number of times (NO in S49), the electric blower 10 is set in a normal waiting state (S52).

This state is the same state as the state in which the stop button is pressed.

In the second example of the current spark detection and control, when the number of stops does not reach the predetermined number of times, the operation of the electric blower is restarted. When a spark is generated, the operation stops immediately, but restarts. Thus, the second example improves convenience and prevents smoke and fire from being generated in the electric blower.

(Third example of spark detection and control)

Unlike the second example of storing the number of operation stops, the third example of current spark detection and control erases the number of operation stops stored in the memory when normal operation is determined.

Referring to Fig. 18, a third example of spark detection and control will be described.

The third example of current spark detection and control detects sparks in the same manner as steps S1 to S6 of the first example in the first embodiment illustrated in FIG. 4 .

It is determined whether a spark is detected and the operation of the electric blower is stopped (S61).

When the spark is not detected, and the operation is not stopped (NO in S61), it is determined whether the operation is a normal operation (S62).

When the electric blower was operated for 30 to 60 seconds without error, it was determined that the operation was normal.

When it is determined that the operation is normal (YES in S62), the stop count is cleared to zero (S63).

After the count is cleared, the process returns to S61.

Meanwhile, when it is determined in S61 that a spark is detected and the operation of the electric blower is stopped (YES in S61 ), steps S64 to S68 that are the same as steps S48 to S52 in the second example are performed.

When it is determined in S62 that the electric blower is not operating normally (NO in S62), the process returns to S61.

In a third example of current spark detection and control, when the electric blower returns to normal, the count is cleared; and when a spark is generated, operation stops immediately, but restarts. Thus, the third example improves convenience and prevents smoke and fire from being generated in the electric blower.

The electric vacuum cleaner according to the second embodiment of the present invention has no error detection, ensuring reliable and stable error detection; not only detecting sparks caused by friction between the rectifier of the electric blower and the carbon brushes, stopping the operation of the electric blower, but also Also after the operation stops, the control device is activated to control the electric blower to prevent smoke and fire from being generated in the electric blower; and it is easy to use. "Electric vacuum cleaner according to the third embodiment"

Now, an electric vacuum cleaner according to a third embodiment of the present invention will be described.

The electric vacuum cleaner according to the third embodiment has the same configuration as the electric vacuum cleaner according to the first embodiment.

Spark detection and control by means of a control circuit of an electric vacuum cleaner according to a third embodiment will be described.

Based on FIG. 19 , spark detection and control of an electric vacuum cleaner according to a third embodiment will be described.

It should be noted that, as with ordinary electric blowers, when the electric blower 10 is activated, the rate of spark generation is high, and then the rate tends to decrease.

The electric vacuum cleaner 1 is used and the electric blower 10 is activated (S71).

Spark detection is performed (S72).

Spark detection is performed in the same manner as steps S1 to S6 of the first example of the first embodiment illustrated in FIG. 4 .

Based on the spark detection information, the control unit 32 stores the absolute value of the difference between the estimated value Ine and the measured value In in the storage unit of the control unit 32 as a detected value (spark amount).

After the electric blower 10 is activated, the control unit 32 detects whether a predetermined time elapses (S73).

Fig. 20 is a graph showing the relationship between the operating time and the amount of spark after the electric blower is activated. As exemplified in FIG. 20 , for example, when the amount of spark becomes stable two minutes after activation, the predetermined time is set to, for example, two minutes.

When the predetermined time has not elapsed after activation (NO in S73), it is determined whether the detection value is equal to or greater than the first predetermined value (S74).

Note that the predetermined value is determined experimentally as follows.

Measure the amount of spark and the time from when the electric blower is activated until the amount of spark becomes stable. Validation of measurements on multiple electric blowers. From these experiments, the highest spark amount at activation, the time until the spark amount became stable, and the spark amount were obtained and multiplied by a safety factor to set predetermined values.

Here, the first predetermined value is obtained by multiplying the maximum detection value exemplified in FIG. 20 by a safety factor (for example, 1.1) to prevent failure.

When the detected value is equal to or greater than the first predetermined value (YES in S74), the control unit 32 stops the operation of the electric blower 10 (S75).

When the detection value is equal to or greater than the first predetermined value, it indicates that sparks are caused by friction between the rectifier 23 and the carbon brush 26 of the electric blower 10 within a predetermined time after activation. Thus, the control unit 32 stops the operation of the electric blower 10 to prevent generation of smoke and fire in the electric blower 10 .

When it is determined in S73 that a predetermined time has elapsed after activation (YES in S73), it is determined whether the detection value is equal to or greater than a second predetermined value (S76).

Here the second predetermined value is obtained by multiplying the stable value exemplified in FIG. 20 by a safety factor (for example, 1.4) to prevent failure.

When the detected value is equal to or greater than the second predetermined value (YES in S76), the control unit 32 stops the operation of the electric blower 10 (S75).

When the detection value is equal to or greater than the second predetermined value, it indicates that sparks are caused by friction between the commutator 23 and the carbon brush 26 of the electric blower 10 during stable operation after a predetermined time has elapsed after activation. Thus, the control unit 32 stops the operation of the electric blower 10 to prevent generation of smoke and fire in the electric blower 10 .

When it is determined in S74 that the detection value is not equal to or greater than the first predetermined value (NO in S74), the process returns to S72, where spark detection is repeatedly performed.

When it is determined in S76 that the detection value is not equal to or greater than the second predetermined value (NO in S76), the process returns to S72, where spark detection is repeatedly performed.

Thus, the determination in S74 and S76 that the detection value is not equal to or greater than the first and second predetermined values respectively indicates that the spark is not caused by the friction between the commutator 23 and the carbon brush 26 in the electric blower 10 . Thus, control circuit 30 allows electric blower 10 to continue to operate.

It should be noted that FIG. 20 is a graph showing the relationship between the operating time after activation of the electric blower and the amount of spark, wherein the first set value and the second set value are determined for each level of power supply voltage exemplified in FIG. 21 . For example, for AC 90V≤power supply voltage<AC 100V, the first setting value is C1, and the second setting value is C2.

As described above, these set values can be changed for each level of power supply voltage, for each operation mode of the electric blower as described in the first embodiment, for each frequency of the power supply, or a combination thereof.

It should be noted that the third embodiment specifies two set values: the first set value and the second set value lower than the first set value, but the set value may also include the set value lower than the second set value. a third set value, and may further include a plurality of set values. It is also to be noted that the power source is not limited to AC power, but may be a wireless power system.

As described above, according to the current electric vacuum cleaner, within a predetermined time after the activation of the electric blower, when the detection value based on the spark detection information from the spark detector is greater than the first predetermined value, the electric blower is controlled such as stopping; and at the predetermined time After elapse, when the detected value is greater than a second predetermined value lower than the first predetermined value, the electric blower is controlled such as stopped.

Therefore, the current electric vacuum cleaner of the third embodiment is different from the conventional method in which a large predetermined value is set within a predetermined time, and thus cannot stop the electric blower by detecting a spark failure at the time of stable operation, or A small predetermined value is set at stable operation, and thereby the electric blower is stopped although the electric blower operates normally when activated, the current electric vacuum cleaner of the third embodiment does not stop the electric blower normally operated, and detects that the electric blower is operated by the electric blower. sparks caused by the friction between the rectifier and the carbon brush in the electric blower, and stop the operation of the electric blower to prevent smoke and fire from being generated in the electric blower.

Thus, the current electric vacuum cleaner of the third embodiment does not stop the normally operating electric blower, detects sparks caused by friction between the rectifier in the electric blower and the carbon brushes, and stops the operation of the electric blower to prevent damage in the electric blower. Smoke and fire are generated, thereby realizing a reliable electric vacuum cleaner.

Claims (15)

1. An electric vacuum cleaner, comprising: a dust collection chamber, which is provided in the main body of the vacuum cleaner; an electric blower, which causes a suction negative pressure to act on the dust collection chamber; a spark detector, which detects the a spark caused by friction between a rectifier and a carbon brush of an electric blower; and a control unit that controls the electric blower based on spark detection information from the spark detector, wherein, The spark detector calculates the difference between the previous value and the latest value of the sampled value, and estimates the next value based on the difference; and when the absolute value of the difference between the estimated value and the measured value is greater than a predetermined value, the The control unit stops the operation of the electric blower. 2. The electric vacuum cleaner according to claim 1, wherein the absolute value of the difference between the estimated value and the measured value is integrated a predetermined number of times, and when the integrated value is larger than the predetermined value, stop the operation of the electric blower. 3. The electric vacuum cleaner of claim 2, wherein the spark detector performs sampling for each of a plurality of frequencies of the power source and averages an integrated value for each frequency of the power source . 4. An electric vacuum cleaner according to any one of claims 1 to 3, wherein the spark detector performs sampling when power is supplied to the electric blower. 5. The electric vacuum cleaner according to any one of claims 1 to 4, further comprising a power supply voltage detector detecting a power supply voltage, wherein the predetermined value is changed according to a voltage detected by the power supply voltage detector. 6. An electric vacuum cleaner according to any one of claims 1 to 4, further comprising a plurality of operating modes, wherein the predetermined value is changed depending on the operating mode. 7. The electric vacuum cleaner according to any one of claims 1 to 4, further comprising a power frequency detector for detecting the frequency of the power supply, wherein, according to the frequency detected by the power frequency detector, the predetermined value. 8. The electric vacuum cleaner of claim 1, wherein: the spark detector determines that a spark has occurred when the difference between the estimated value and the measured value is greater than the predetermined value; and The control unit stops the operation of the electric blower, and prevents reactivation of the electric blower after stopping the operation of the electric blower. 9. The electric vacuum cleaner according to claim 8, wherein, when the spark detector determines that a spark is generated, the control unit stops the operation of the electric blower, and enables the electric blower to continue operating until stopped The number of times the quantity reaches a predetermined quantity. 10. The electric vacuum cleaner according to claim 9, wherein even if the electric blower is stopped immediately due to generation of sparks, the stored stop count is cleared when the electric blower returns to normal. 11. An electric vacuum cleaner according to any one of claims 8 to 10, further comprising a notification device which detects the generation of a spark and notifies the electric blower to stop. 12. The electric vacuum cleaner of claim 1, wherein: The predetermined value includes a plurality of predetermined values; within a predetermined time from activation of the electric blower, setting a first predetermined value; and After the predetermined time elapses, a predetermined value lower than the first predetermined value is set. 13. The electric vacuum cleaner according to claim 12, wherein the plurality of predetermined values are set for each operation mode of the electric blower; and the predetermined values are changed by switching the operation modes. 14. The electric vacuum cleaner according to claim 12, wherein the plurality of predetermined values are set for each frequency of the power source; the frequency of the power source is detected; and, based on the detected result, the predetermined value. 15. The electric vacuum cleaner according to claim 12, further comprising a power supply voltage detector for detecting a power supply voltage value, wherein the plurality of predetermined values are set for each level of power supply voltage; and, for the power supply voltage Each level of voltage detected by the detector changes the predetermined value.

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