JP4654793B2 - Dust detection device and electric vacuum cleaner using the same - Google Patents

Description

  The present invention relates to a dust detection device that detects dust passing over an air passage of a vacuum cleaner.

  As a conventional dust detection device, there is a dust detection device for a vacuum cleaner as described below.

Conventionally, this type of dust detection apparatus has a configuration as shown in FIGS. 6 and 7, a light emitting unit 230 that emits light into an air passage through which dust flows, and a light receiving unit 231 that receives light from the light emitting unit 230 and outputs a signal corresponding to the amount of received light are an air passage through which dust flows. The light emitting unit 230 is provided opposite to the light emitting unit 230 (hereinafter, the light emitting unit 230 and the light receiving unit 231 are collectively referred to as a dust sensor 23). After the output signal Vs from the light receiving unit 231 is amplified by the amplification unit A232, the signal Va is converted to the pulse Sa by the pulse conversion unit A235 and input to the dust determination unit 238. The dust judgment means 238 counts the number of the pulses Sa, and simultaneously measures the pulse width and corrects to increase the number counted to the pulse Sa when the pulse width is wide, that is, when the dust is large. When the count of the dust judgment means 238 is large, control is performed to increase the input of the fan motor 11. By doing so, dust can be sucked with a stronger suction force as the dust becomes larger, and cleaning can be performed with an optimum suction force according to the dust (see, for example, Patent Document 1).
Japanese Patent Publication No. 7-28847

  At present, due to changes in living environment, interest in house dust including pollen has increased, and a dust detection device for a vacuum cleaner that can detect these small dusts has been demanded.

  However, in the conventional invention, when the size of the dust is determined based on the pulse width, the pulse width hardly changes even if the size of the dust changes if the dust is sufficiently smaller than the light receiving unit 231. For example, when dust passes through a circular light receiving unit 231, if the size of the passing dust is a sphere with a diameter X, the size of the light receiving unit is a circle with a diameter Y, and the passing speed is Z, the passing time is (X + Y ) / Z, however, when X << Y, the passing time is Y / Z, and the change in the passing time due to the size of the dust is almost eliminated, and it is difficult to determine the size of the dust. Even if it is attempted to determine the size of the dust by directly looking at the change in Va, if the sand particles and pollen are viewed simultaneously, the change in the amount of light received by the light receiving unit 231 is proportional to the area that blocks the light hitting the light receiving unit 231. Therefore, when the size of the light receiving portion 231 is larger than the sand particles, assuming that (the diameter of the sand particles) :( the diameter of the pollen) = 100: 1, the ratio of the change in the amount of received light is 1002: 12 = 10000: 1, It has been difficult to correctly detect the size of dust having such a wide range of changes.

In order to solve the above-described conventional problems, the present invention provides a dust detection unit, an amplification unit that amplifies a signal from the dust detection unit , and a dust determination that determines the size of dust based on the signal from the amplification unit. And amplifying means having a plurality of amplification levels according to the size of dust, and simultaneously outputting a plurality of signals obtained by amplifying signals from the dust detection means with the plurality of amplification degrees. And the dust discriminating means discriminates the size of the dust based on the plurality of signals output from the amplifying means , thereby detecting dust containing smaller fine dust by size. A detection device can be provided to the user.

  In the present invention, by using a plurality of amplification means having a plurality of amplification degrees according to the size of dust, dust containing smaller fine dust can be detected by size. By using this to control the input to the fan motor and changing the suction force, for example, when used in a vacuum cleaner, cleaning can be performed with an optimum suction force according to the surface to be cleaned.

The first invention includes dust detection means, amplification means for amplifying a signal from the dust detection means , and dust determination means for determining the size of dust based on the signal from the amplification means , The amplification means has a plurality of amplification levels according to the size of dust, and simultaneously outputs a plurality of signals obtained by amplifying signals from the dust detection means with the plurality of amplification degrees. A dust detection device for a vacuum cleaner that can detect dust containing smaller fine dust according to size by determining the size of the dust based on the plurality of signals output from the amplification means. Can be provided to the user.

According to a second invention, in the first invention, the amplifying means has a plurality of filter parts that amplify and pass frequency components in a band in accordance with the size and passing speed of the dust. It is possible to provide a user with a dust detection device for a vacuum cleaner that can remove noise and the like and reliably detect dust.

  According to a third aspect of the present invention, the dust detection means of the first or second aspect of the invention includes a light emitting unit that emits light into an air passage through which dust flows, a light from the light emitting unit, and a signal corresponding to the amount of light received. It is comprised with the light-receiving part to output, and a dust detection means is comprised more concretely.

  According to a fourth invention, in the second invention, since at least one of the plurality of filter portions of the amplification means has a different cutoff frequency, each of the amplification means focuses on a signal of a target size. Therefore, it is possible to distinguish and detect the size of the dust more reliably.

  The fifth invention includes a plurality of amplifying means in addition to the fourth invention, and the amplifying means having the lowest cut-off frequency of the high-pass filter of the filter section or having no high-pass filter in the filter section is the other amplifying means. By detecting a large amount of dust compared to the means, when a large amount of dust comes in, the light change time of the light receiving part is long and the passing speed is slow, so a signal in a low frequency band is input. By using it, dust can be detected more accurately.

  The sixth invention includes a plurality of amplification means in addition to the second invention, and at least one amplification means shares the same signal input in parallel with the other amplification means, and therefore, the amplification arranged in parallel. The means can independently set the amplification degree and the cut-off frequency of the filter unit, so that the degree of freedom of setting can be increased.

  The seventh invention includes a plurality of amplifying means in addition to the second invention, and at least one amplifying means is configured to further amplify the signal amplified by the other amplifying means. Since it is not necessary to connect all the amplifying means in parallel, the input impedance of the amplifying means with respect to the output of the light receiving part can be increased to increase the stability of the light receiving part, and further, the amplified signal is reused and amplified. As a result, the degree of amplification can be small, and the cost for amplification can be reduced.

  An eighth invention includes the dust detection device according to any one of the first to seventh inventions, a fan motor that generates suction air, and a control unit that controls an input to the fan motor, wherein the control unit is configured to detect the dust. Since the input to the fan motor is changed according to the output of the apparatus, for example, when used in a vacuum cleaner, cleaning can be performed with an optimum suction force according to the condition of the surface to be cleaned.

(Embodiment 1)
Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the component of the same structure as the past, and description is abbreviate | omitted.

  FIG. 1 is a block diagram of a dust detection device for a vacuum cleaner according to Embodiment 1 of the present invention. In FIG. 1, reference numerals 230 and 231 denote a light emitting part and a light receiving part as dust detection means. The light emitting part 230 emits light into the air passage through which dust flows, and the light receiving part 231 receives light from the light emitting part 230. And outputs a signal corresponding to the amount of light received, and is provided opposite to the light emitting unit 230 in an air passage through which dust flows. The output signal Vs from the light receiving unit 231 is amplified by the amplification unit A232 and the amplification unit B233, respectively. The amplifying unit A232 includes an amplifying unit A2320 and a filter unit A2321 including a high-speed arithmetic processing CPU such as an operational amplifier and a DSP, and amplifies Vs around a specific frequency band (hereinafter referred to as frequency band A). The signal Va is output, the pulse conversion means A235 converts it into a pulse, and the output signal Sa is input to the dust discrimination means 238 for discriminating the amount and type of dust. Similarly, the amplifying unit B233 includes an amplifying unit B2330 and a filter unit B2331 including a high-speed arithmetic processing CPU such as an operational amplifier and a DSP, and amplifies Vs around a specific frequency band (hereinafter referred to as frequency band B). The signal Vb is output, and this is converted into a pulse by the pulse conversion means B236, and the output signal Sb is input to the dust determination means 238. The dust discriminating means 238 judges the size and amount of dust at the place to be cleaned by inputting two signals Sa and Sb. The amplification means A232 has an amplification degree aimed at detecting dust larger than sand grains having a diameter of about 200 μm, and the amplification means B233 has an amplification degree of about 20 μm from pollen having a diameter of about 200 μm, which is the aim of the amplification means A. The amplification level is aimed at detecting each trash.

  The operation of the dust detection device for a vacuum cleaner configured as described above will be described.

  If dust flows into the air passage during cleaning, the light from the light emitting unit 230 is blocked by the dust, and the amount of light received by the light receiving unit 231 decreases and the output voltage Vs decreases. This Vs is amplified by the amplification unit A2320 through the filter unit A2321, and the signal Va is output. The filter unit A2321 is a bandpass filter including a highpass filter having a cutoff frequency fa1 and a lowpass filter having a cutoff frequency fa2, and is configured to amplify around a specific frequency band A (fa1 to fa2). The frequencies fa1 and fa2 are frequencies calculated based on the speed at which the dust passes through the dust sensor 23.

  A method for calculating the frequencies fa1 and fa2 will be described below. If each of the light emitting unit 230 and the light receiving unit 231 has a circular shape with a diameter Y, and the dust to be detected is a sphere with a diameter X, a cylinder (hereinafter referred to as region R) with the light emitting unit 230 and the light receiving unit 231 facing each other as an upper base and a lower base, respectively. The amount of light received by the light receiving portion 231 is the lowest when the dust passes through the inside of the light receiving portion 231. FIG. As shown in FIG. 2 and 3, when the dust passes through the dust sensor 23, (a) before the dust passes, (b) when the dust crosses the outer wall of the region R (when entering the region R), (c) There are five states when the waste enters the region R (d) when the waste intersects with the outer wall of the region R (when leaving the region R), and (e) when the waste has passed. The change in the amount of light received by the light receiving unit 231 at this time depends on the size of the dust and the speed of passing through the dust sensor 23. The larger the dust, the larger the amount of change and the longer the change time. The change time becomes shorter. The amplifying unit A232 utilizes the change in the amount of received light at the time of (A), filters the change in the amount of received light with the filter unit A2321, and amplifies it with the amplifier unit A2320.

  When the dust enters the center of the region R at a speed Z, the time T in (a) is T = X / Z when the dust is small and X ≦ Y, and the dust is large and X ≧ Y. Sometimes T = Y / Z.

  Accordingly, if the diameter Y of the light receiving portion 231 is 3 mm, in the case of the amplifying unit A232, in consideration of detecting dust larger than sand particles having a diameter of about 200 μm, the target of the size of the detected dust is X ≧ 200 μm. T is 200 μm / Z ≦ T ≦ 3 mm / Z. If the range of the passing speed Z is set, T and frequencies fa1 and fa2 corresponding to the T are determined. The amplification means A232 filters and amplifies the input signal Vs with the frequency bands fa1 to fa2 determined by the above method, and the output signal Va is input to the pulse conversion means A235. By doing so, it is possible to remove only noise and extract only the signal that the dust passes through the dust sensor 23.

  Similar to the amplification unit A232, the amplification unit B233 outputs a signal Vb obtained by amplifying Vs around a specific frequency band B (fb1 to fb2). Considering that fb1 and fb2 can mainly detect pollen of about 20 μm, and that dust of 200 μm or more can be detected by the amplification means A232, the target size of the detected dust is 20 μm ≦ X <200 μm. Therefore, T is 20 μm / Z ≦ T ≦ 200 μm / Z. If the range of the passing speed Z is set, T and frequencies fb1 and fb2 corresponding to the T are determined. Since the amplifying unit B233 can narrow the frequency band B compared to the amplifying unit A232, the amplifying unit B233 is more resistant to noise and can amplify only the dust signal, so that the dust can be more accurately collected. Can be detected.

  In actual design, fa1, fa2, fb1, and fb2 depend on circuit elements and mechanisms constituting the amplifying means, a position where dust passes through the region R, and the like. For example, the characteristics of the operational amplifier, the irregular reflection of light from the light emitting unit 230 in the dust passage path, the fact that dust passes outside the center of the region R, and the amount of light received by the light receiving unit 231 even if the dust passes outside the region R It is set in consideration of slight changes. Also, with regard to the passage speed Z, even when dust is sucked in with the same air volume using a vacuum cleaner, the speed passing through the dust sensor 23 varies depending on the size of the dust, and the larger the dust, the slower the passage speed. For example, Z used for setting the filter of the amplifying unit A232 for detecting large dust is set lower than Z of the amplifying unit B233, and the value of Z used for calculation is adjusted according to the target dust to be detected. Therefore, the cut-off frequency fa1 of the high-pass filter of the filter unit A2321 is set lower than the cut-off frequency fb1 of the high-pass filter of the filter unit B2331, and the dust is detected more accurately by setting the frequency according to the large dust. can do.

  The signals Va and Vb amplified by these amplifying means are converted into pulses by the pulse converting means A235 and pulse converting means B236, respectively, and the pulses Sa and Sb are input to the dust discriminating means 238. Then, the dust discriminating means 238 judges the size and amount of dust at the place to be cleaned based on the number of two pulses Sa and Sb. Further, since the pulse Sa is a signal for a large dust, unlike the Sb, the amount of change in the pulse width due to the size of the dust is large, so the pulse width is also detected to determine the size of the dust. To do.

  The control means 10 changes the input to the fan motor 11 according to the size and amount of the dust judged by the dust discrimination means 238, and sets the optimum input according to the kind of dust. For example, when only small fine dust is detected, dust can be sucked without increasing the suction force. Therefore, the input to the fan motor 11 does not increase so much. Conversely, when large dust is detected, the fan motor 11 Increase the input to be able to suction the garbage. By carrying out like this, it can clean with the optimal suction | attraction force according to the condition of the surface to be cleaned.

  Further, the display means 14 is composed of two level meters, such as a sand level display unit 141 and a dust level display unit 142, according to the size of the dust as shown in FIG. 4, and according to the number of pulses of Sa and Sb, respectively. By changing the display, the user can be informed of the status of the dust on the surface to be cleaned.

(Embodiment 2)
The second embodiment of the present invention will be described below with reference to the drawings. Note that parts having the same configurations as those of the conventional and the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 5 is a block diagram of a dust detection device for a vacuum cleaner according to Embodiment 2 of the present invention. The arrangement of the amplifying means B233 is different from that of the first embodiment, and the output signal Va of the amplifying means A232 is input to the amplifying means B233, and the side that detects small dust is two-stage amplification.

  With such a configuration, the input impedance of the amplifying unit with respect to the output signal of the light receiving unit 231 can be increased as compared with the first embodiment, so that the stability of the light receiving unit can be increased. Further, the amplification means B233 increases the amplification degree in order to detect smaller dust. However, unlike the first embodiment, the amplification degree is smaller than that of the amplification means A232, so that the cost for amplification is low. Can be reduced. On the contrary, in the configuration of the first embodiment, since the amplifying means are arranged in parallel, the cutoff frequency of the filter unit can be set independently of each other, and it may be influenced by noise generated by other amplifying means. There is an advantage that it is lost.

  As for the setting of the frequency band A and the frequency band B, when the diameter Y of the light receiving unit 231 is 3 mm, the amplification unit A232 detects dust larger than sand particles having a diameter of about 200 μm and targets the output signal Va to a diameter of 20 μm. In consideration of the use of the amplifying means B233, since the target of the size of dust to be detected is X ≧ 20 μm, T becomes 20 μm / Z ≦ T ≦ 3 mm / Z, and the range of the passing speed Z is set. T and frequencies fa1 and fa2 corresponding to T are determined. The amplification means A232 filters and amplifies the input signal Vs with the frequency bands fa1 to fa2 determined by the above method, and the output signal Va is input to the pulse conversion means A235 and the amplification means B233.

  As for the amplification means B233, considering that pollen of about 20 μm can be mainly detected, and that the dust of 200 μm or more can be detected by the amplification means A232, the aim of the size of the detected garbage is 20 μm ≦ X <200 μm. Therefore, T is 20 μm / Z ≦ T ≦ 200 μm / Z. If the range of the passing speed Z is set, T and frequencies fb1 and fb2 corresponding to the T are determined. Since the upper limit of T is smaller in the amplifying unit B233 than in the amplifying unit A232, the frequency fb1 of the high pass filter can be made higher than the fa1 of the amplifying unit A232 and the frequency band B can be narrowed. Since only the dust signal can be further amplified, the dust can be detected more accurately.

  The dust detecting means has been described by taking the light receiving section and the light emitting section as an example, but any means may be used as long as dust detection can be performed in the same manner as the light receiving section and the light emitting section.

  As described above, the dust detection device for a vacuum cleaner according to the present invention can detect dust containing smaller fine dusts by size by having a plurality of amplification degrees according to the size of the dust. Therefore, when used in a vacuum cleaner, it is possible to change the suction force by controlling the input to the fan motor and to perform cleaning with the optimum suction force according to the surface to be cleaned. Useful for control according to size.

The block diagram of the dust detection apparatus of the vacuum cleaner in the 1st Embodiment of this invention The figure which shows the state when garbage passes a garbage sensor in the same embodiment The figure which shows the change of the light reception amount of the light-receiving part according to speed when garbage passes a garbage sensor in the same embodiment Front view of display means The block diagram of the dust detection apparatus of the vacuum cleaner in the 2nd Embodiment of this invention Block diagram of a conventional vacuum cleaner Cross section of a conventional vacuum cleaner dust sensor

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Control means 11 Fan motor 14 Display means 23 Waste sensor 141 Sand level display part 142 Dust level display part 230 Light emission part (dust detection means)
231 Light-receiving part (dust detection means)
232 Amplifying means A
233 Amplifying means B
235 Pulse conversion means A
236 Pulse conversion means B
238 Waste discrimination means 2320 Amplification part A
2321 Filter part A
2330 Amplifier B
2331 Filter B

Claims (8)

A dust detection unit; an amplification unit that amplifies a signal from the dust detection unit; and a dust determination unit that determines a size of the dust based on the signal from the amplification unit. And a plurality of signals obtained by amplifying the signals from the dust detection means at the plurality of amplification degrees at the same time, and the dust discrimination means outputs from the amplification means. A dust detection device that determines the size of dust based on the plurality of signals . The dust detection device according to claim 1, wherein the amplifying unit includes a plurality of filter units that amplify and pass a frequency component in a band in accordance with a size and a passing speed of the dust. 3. The dust detection means comprises a light emitting part that emits light into an air passage through which dust flows, and a light receiving part that receives light from the light emitting part and outputs a signal corresponding to the amount of light received. Dust detection device. 3. The dust detection device according to claim 2, wherein at least one different frequency is set for each cutoff frequency of the filter unit of the amplification means. 5. The amplifying means comprising a plurality of amplifying means and having the lowest cut-off frequency of the high-pass filter in the filter section or having no high-pass filter in the filter section detects larger dust than other amplifying means. Dust detection device. 3. The dust detection device according to claim 2, further comprising a plurality of amplifying means, wherein at least one amplifying means is arranged in parallel with other amplifying means and shares the same signal input. 3. The dust detection device according to claim 2, further comprising a plurality of amplifying means, wherein at least one amplifying means further amplifies the signal amplified by the other amplifying means. A dust detection device according to any one of claims 1 to 7, a fan motor that generates suction air, and a control unit that controls input to the fan motor, wherein the control unit outputs an output of the dust detection device. A vacuum cleaner that changes the input to the fan motor according to the condition.

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