JP2008086124A - Motor control apparatus, vacuum cleaner and hand dryer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost and simple motor control apparatus with high detection precision, where a high-pass filter for extracting noise components is not necessary to be installed for detecting the motor current by an A/D converter, and it is not necessary to integrate the value detected by the A/D converter with an integrator and conversion speed of the A/D converter is not high, and to provide a vacuum cleaner and a hand dryer. <P>SOLUTION: The output of a current-detecting means 31 for measuring motor current is sampled by the A/D converter 33 for the prescribed number of times, for example, once, with a prescribed timing T1 from zero cross of commercial power voltage at each half cycle of commercial power so that the motor current value in a prescribed phase angle is measured, and will not extract only the noise component. Abnormality of sparks is decided from the size of the difference between a maximum value and a minimum value, within a prescribed time of the detection value of sampled current, so that a motor 2 is controlled. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric motor control device that controls an electric motor having a commutator and a brush, an electric vacuum cleaner equipped with the electric motor control device, and a hand dryer.

  The conventional electric motor control device includes, for example, “an electric blower composed of a fan and a commutator motor, and a spark detection means for detecting a spark generated from the commutator motor, and a commutator according to an output from the spark detection means. Controlling the motor ... "has been proposed (for example, see Patent Document 1).

JP 2001-136780 A

  In a conventional motor control device, a high-pass filter is used, and the output of the current sensor is sampled by an A / D converter at a predetermined period from a predetermined timing T1 from the zero cross of the commercial power supply voltage, and the previously sampled voltage and This is a comparison of the voltage levels sampled this time, and sparks (hereinafter also referred to as sparks) will occur if the voltage change that changes within one frequency supplied from the power supply changes continuously. In this case, it is determined that a spark has occurred when the voltage change is discontinuous. However, in this configuration, noise components are extracted, so external noise other than the original measurement noise components will also be measured. Therefore, there is a risk of misjudgment of spark generation and the accuracy of spark detection. There was a problem of lowering.

  In addition, sampling is performed at a predetermined sampling period from a predetermined timing T1, but the sampling period needs to be equal to or longer than the A / D conversion time of the A / D converter. If the sampling period is reduced to increase the value, a high-performance microcomputer or the like with a high processing speed is required to enable data processing to determine the occurrence of sparks and processing of other processes. There was a problem that the cost would be high. In particular, this problem becomes significant in the prior art in which changes in one cycle of the current supplied from the power source are extracted by a high-pass filter.

  In other words, in the prior art in which the change in one cycle of the current supplied from the power source is extracted by a high-pass filter in order to determine the occurrence of spark, the sampling period for comparing the current measurement with the previous measurement is at least a difference in magnitude of the noise component due to the spark. It needs to be within a time range much shorter than one frequency of the current supplied from the generated power supply, and the conversion speed of the A / D converter and the processing speed of processing this signal to determine the occurrence of sparks are fast. There was a problem that a high-performance microcomputer or the like was required and the cost was high.

  In addition, when the sampling period is small, the difference between the current measurement and the previous measurement is a small value of only the noise component due to the occurrence of sparks. Therefore, the A / D converter must have a high resolution or high accuracy, There was a problem of high costs.

  The present invention has been made to solve the above-described problems, and can detect the occurrence of a spark with a configuration with high detection accuracy and at a low cost, and can detect an abnormality when an abnormal spark occurs. An object of the present invention is to provide an electric motor control device, a vacuum cleaner, and a hand drying device that can control an electric motor so as to prevent smoke and ignition due to overheating.

  An electric motor control device according to the present invention includes a driving unit that controls operation of an electric motor having a commutator and a brush, a spark detection unit that detects occurrence of a spark generated in the electric motor at a predetermined sampling timing, and the spark detection Spark determining means for determining a spark abnormality from the output of the means, and the driving means controls the electric motor in accordance with the output of the spark determining means.

  The electric motor control device according to the present invention detects the occurrence of a spark generated by an electric motor having a commutator and a brush, determines an abnormality of the spark, and controls the operation of the electric motor according to the determination, thereby generating a spark. Can be realized with an inexpensive configuration with high detection accuracy, and the electric motor can be controlled to prevent smoke and ignition due to abnormal overheating when an abnormal spark occurs.

Embodiment 1 FIG.
1 is a block configuration diagram of an electric motor control apparatus according to Embodiment 1 of the present invention. In FIG. 1, the motor control device includes a spark detection unit 3, a spark determination unit 4, and a drive unit 5. It controls the operation of. Further, the spark detection means 3 includes a current detection means 31 for detecting the current flowing through the electric motor 2, a rectification means 32 for rectifying the output of the current detection means 31, and an output A for detecting the output of the rectification means 32 as a digital value. / D conversion means 33. The spark determination unit 4 determines the occurrence of a spark from the detection result of the A / D conversion unit 33 and outputs the determination result to the drive unit 5. The drive means 5 is composed of, for example, a triac or the like, and controls the electric motor 2 based on the output of the spark determination means 4. Details of the operation of the first embodiment having such a configuration will be described below with reference to FIGS.

  FIG. 2 is a waveform diagram showing a commercial power supply waveform in the first embodiment of the present invention, FIG. 3 is a waveform diagram showing a detection waveform of the spark detection means in the first embodiment of the present invention, and FIG. FIG. 3B is a waveform diagram in which the current detection means 31 detects the current flowing in the motor 2 when no spark is generated, and FIG. 3B shows the current detection means 31 detecting the current flowing in the motor 2 when the spark is abnormal. FIG. 3C is a waveform diagram obtained by rectifying the output of the current detecting means 31 by the rectifying means 32. FIG. 4 is a diagram showing the detection timing of the spark detection means and the operation of the spark determination means in Embodiment 1 of the present invention. FIG. 4 (a) shows the output of the rectification means 32 detected by the A / D conversion means 33. FIG. 4B is a sampling timing diagram, FIG. 4B is a detection value obtained by detecting the output of the rectifying means 32 by the A / D conversion means 33, and FIG. 4C is a current data and previous data of a detection value of the A / D conversion means 33. FIG. 4 (d) is a diagram showing a determination result of the spark determination means 4, and FIG. 4 (e) is a spark determination means. 4 is a diagram illustrating an operation state of the electric motor 2 controlled by the driving unit 5 based on the determination result of FIG. 5 is a diagram showing the internal configuration of the electric motor and the relationship between the spark and the motor current in the first embodiment of the present invention. FIG. 5 (a) shows the magnitude of the spark generated between the commutator and the brush. FIG. 5B is a schematic diagram illustrating the relationship between the spark voltage Va and the motor current Im.

  First, when the electric motor 2 is not driven, no spark is generated, so that the spark determination means 4 determines that the spark is normal, and the driving means 5 supplies the commercial power supply voltage shown in FIG. The electric motor 2 starts operation. The detected waveform of the current detection means 31 when the spark after the start of operation is normal becomes a waveform as shown in FIG. 3A. However, when a spark occurs in the electric motor 2, a voltage drop due to the spark occurs, and the electric motor 2 Since the applied voltage decreases, the current flowing through the motor 2 (hereinafter referred to as motor current) also decreases, and the detection waveform of the current detection means 31 is as shown in FIG. In this phenomenon, since the spark is unstable, the voltage drop acting on the electric motor 2 is also unstable, and as a result, the motor current is also unstable. Such a phenomenon will be described in more detail with reference to FIG.

  In FIG. 5A, the relationship between the spark voltage Va of the spark generated between the commutator 2b around which the stator winding is wound and the brush 2c and the motor current Im flowing through the electric motor 2 is When the voltage is Vs and the impedance of the electric motor 2 is Zm, the spark voltage at the two locations of the brushes 2c1 and 2c2 is 2Va, so it can be regarded as Im = (Vs-2Va) / Zm. Here, for the sake of convenience, assuming that Zm does not change in magnitude due to the occurrence of a spark, the motor current Im1 flowing through the electric motor 2 when no spark is generated is the spark voltage Va = 0 (zero). = Vs / Zm. However, since a spark voltage Va is generated when a spark is generated, if the current flowing through the electric motor 2 at this time is Im2, Im2 = (Vs−2Va) / Zm. Since Va is equal to or greater than 0, when considering the motor current Im in the above case, Im1> Im2. At this time, since the spark voltage Va changes in proportion to the magnitude of the spark, when applied to the above-described equation representing the motor current Im flowing through the electric motor 2, the motor current Im results in proportion to the magnitude of the spark. Will also change.

  The relationship between the spark voltage Va and the motor current Im is as shown in FIG. 5B. Since the spark is unstable, the spark voltage Va is one of the peak values of the motor current Im that are unstable. It acts like a variable. That is, when the peak current of the motor current Im is measured, a current peak appears almost in synchronization with the maximum value of the voltage of the commercial power supply 1. When a spark is generated, a spark voltage Va proportional to the magnitude of the spark is generated, which makes the effective value and instantaneous value of the motor current Im unstable. Further, since the contact state between the commutator 2b and the brush 2c is also unstable, the contact resistance value is also unstable, and the motor current is unstable due to this influence. That is, it is possible to determine the occurrence of a spark from the amount of change in the peak value of the motor current, and it is possible to estimate from the peak value to the magnitude of the occurrence of the spark.

  Based on such a concept, the output of the current detection means 31 for detecting the motor current is, for example, full-wave rectified by a rectifier 32 by a diode bridge (not shown) or the like as shown in FIG. . The A / D converter 33 samples the output of the rectifier 32 a predetermined number of times with a phase difference of a predetermined time in synchronization with the cycle of the commercial power source 1. That is, as shown in FIG. 4A, for example, a quarter cycle of the commercial power source 1 after a predetermined timing T1 from each zero cross (zero cross 1 to zero cross 6 in FIG. 2) of the positive side and the negative side of the commercial power source voltage. The output of the rectifying means 32 shown in FIG. 3C is sampled once, for example, at the time of (T1 = 5 ms when the frequency of the commercial power supply is 50 Hz). The detection values sampled by the A / D conversion means 33 in this way are as shown in FIG.

  Next, as shown in FIG. 4C, the spark determination unit 4 obtains the amount of change (absolute value of the difference) between the current data value and the previous data value of the digital value sampled by the A / D conversion unit 33. This is repeated sequentially. At this time, the spark determination means 4 compares the obtained change amount with a predetermined spark abnormality determination level set in advance, and determines that the spark is abnormal when the change amount exceeds the spark abnormality determination level. Since the spark abnormality determination level varies depending on the electric motor 2, it is preferable to set it based on an experimental value obtained by measuring an actual change amount or the like when a spark occurs.

  FIG. 4 (d) shows a detection example of the spark determination means 4 determined at the spark abnormality determination level with respect to the current change amount of FIG. 4 (c). The spark determination means 4 is shown in FIG. 4 (c). Current change amounts ΔI1 to ΔI4 are lower than the spark abnormality determination level, so it is determined that the sparks are normal. However, since the current change amount ΔI5 is higher than the spark abnormality determination level, it is determined that the sparks are abnormal. To output the judgment result.

  The drive unit 5 controls the electric motor 2 based on the output of the spark determination unit 4. The control of the electric motor 2 is performed such that, for example, the electric power supply to the electric motor 2 is cut off and the operation is stopped so that the motor 2 can ensure safety without causing smoke or ignition. It is also possible to continue the operation by supplying electric power that can ensure safety without shutting off the electric power supply that stops the operation of the electric motor 2, for example, from the weak operation mode during normal use However, it is possible to perform control by a method with a smaller supply power. With such a method, it is possible to avoid a situation in which the user cannot suddenly use the device while using it.

  In addition, when a spark abnormality is detected in this way, in the configuration in which control is performed using a method with low power supply, spark detection is continued even in the subsequent operation state, and further spark abnormality is detected. In this case, the power supply may be reduced stepwise so as to control with smaller power, and the power supply may be cut off if the spark abnormality is still detected. With such a method, it is possible to avoid a situation in which the user cannot suddenly use the device while using it, and further safety can be ensured.

  As described above, in the first embodiment, it is possible to detect a spark generated in the electric motor 2 to determine an abnormality of the spark, and to control the operation of the electric motor 2 according to this determination. According to the present embodiment, the detection of the occurrence of the spark can be realized with a high detection accuracy and an inexpensive configuration by sampling twice in one cycle, and due to the abnormal overheating when the abnormal spark occurs. The electric motor can be controlled to prevent smoking and ignition.

  In addition, by detecting the motor current flowing in the motor 2 and sampling the output obtained by rectifying the detected motor current as a digital value, a high-pass filter or the like for extracting a noise component becomes unnecessary, and external noise is measured. Therefore, it is possible to prevent an erroneous determination of the occurrence of a spark as much as possible, and the detection of the occurrence of a spark can be realized with an inexpensive configuration with high detection accuracy. Accordingly, it is possible to provide a safe motor control device that is extremely simple as a control device, has a small number of components, is inexpensive, has high reliability, and does not emit smoke or ignite due to a spark abnormality.

  In addition, in the sampling of the motor current, since the motor current value at a predetermined phase angle is sampled, sampling is performed once at a predetermined timing T1 from the commercial power supply voltage zero cross every half cycle of the commercial power supply voltage. It is not necessary to require high-speed A / D conversion or data processing, and an A / D converter with a general conversion speed or a microcomputer with a general data processing speed may be used. Thus, it is possible to provide a safe motor control device that does not emit smoke or fire due to an abnormal spark.

  Further, the spark determination means 4 obtains a change amount (absolute value of the difference) between the current data value and the previous data value of the digital value sampled by the A / D conversion means 33, and determines the obtained change amount and the spark abnormality judgment level. Therefore, it is determined that the spark is abnormal. Therefore, an integration means for adding a small amount of detection values and accumulating them becomes unnecessary, and detection of the occurrence of spark can be realized with an inexpensive configuration. Therefore, it is possible to provide a safe motor control device that is inexpensive and does not emit smoke or ignite due to an abnormal spark.

  In addition, when the spark determination unit 4 determines that the spark is abnormal, the drive unit 5 is configured to control to stop the operation by shutting off the power supply to the electric motor 2, thereby generating a spark abnormality. Therefore, it is possible to stop the operation of the electric motor 2 and to provide a safe electric motor control device that does not emit smoke or ignite due to an abnormal spark.

  In the first embodiment, the case where the motor current is detected for each of the zero crosses on the positive side and the negative side of the commercial power supply voltage (zero cross 1 to zero cross 6 in FIG. 2) has been described. The same detection is possible not only on the positive electrode side (zero crosses 1, 3, 5 in FIG. 2) but on the negative electrode side (zero crosses 2, 4, 6 in FIG. 2). With such a configuration, it is possible to further reduce the cost while maintaining the measurement accuracy at substantially the same level as described above, and to further reduce the influence of external noise. Furthermore, the structure which restrict | squeezes the waveform to detect, for example to 1 piece in 10 pieces and 1 piece in 20 may be sufficient. If constituted in this way, the further cost reduction can be aimed at. However, if the aperture is too narrow, it is not desirable because fluctuations in the power supply voltage affect the detection of the occurrence of sparks. Therefore, it is desirable to sample at least once per second.

  Furthermore, in the first embodiment, the predetermined timing T1 for A / D converting the output of the rectifying means 32 for measuring the motor current is changed from the zero cross of the commercial power supply voltage to the 1/4 cycle of the commercial power supply 1. The case where the time, for example, T1 = 5 ms has been described, but the present invention is not limited to this. For example, the time may be 4 ms or 6 ms, and the present data value after A / D conversion of the motor current is compared with the previous data value. Needless to say, if the predetermined timing T1 is the same, the same detection can be performed without any problem.

  Further, in the first embodiment, the output of the current detection unit 31 is sampled by the A / D conversion unit 33 without separating the frequency component and the noise component of the commercial power supply voltage. When the influence of the noise component is strong or when it is affected by external noise, an appropriate cut-off frequency is set, and an appropriate position of the circuit, for example, the front stage of the A / D conversion means 33 or the rear stage of the current detection means 31. Needless to say, more reliable spark detection can be achieved by providing a low-pass filter. With this configuration, noise components can be removed more favorably, and safety and the like can be improved by performing accurate spark detection.

  Furthermore, in the first embodiment, the digital value is detected by the A / D conversion means 33 after the output of the current detection means 31 is rectified by the rectification means 32, but the electronic circuit is appropriately provided without providing the rectification means 32. Even if the output of the current detection means 31 is directly detected by the A / D conversion means 33 by designing the data or appropriately processing the detection value of the A / D conversion means 33, the same effect can be obtained. Needless to say.

  Furthermore, in the first embodiment, the case where the rectifying means 32 performs full-wave rectification by a diode bridge or the like has been described. However, if the timing of sampling by the A / D conversion means 33 is appropriate even in the half-wave rectifier circuit, Needless to say, similar effects can be obtained. With such a configuration, it is possible to further reduce the cost while maintaining the measurement accuracy at substantially the same level as described above, and to further reduce the influence of external noise.

  Furthermore, in the first embodiment, a configuration has been described in which A / D conversion is performed only once after a predetermined timing T1, but when performing A / D conversion a plurality of times after the predetermined timing T1, a plurality of A / D conversions are performed. The average value processing may be performed on the data obtained by performing A / D conversion for the number of times, and the average value processed value may be handled as data after a predetermined timing T1. In the case of such a configuration, a higher performance circuit element, a microcomputer or the like is required, but it is possible to further improve the accuracy of spark detection.

  Further, in the first embodiment, the predetermined timing T1 has been described based on the zero cross of the commercial power supply voltage as a base point. However, the same effect can be obtained even if the predetermined timing T1 is configured based on the predetermined voltage value of the commercial power supply voltage. Needless to say.

Embodiment 2. FIG.
In the second embodiment, a description will be given of a mode in which power supplied to the electric motor 2 is controlled by phase control. Hereinafter, the second embodiment will be described with reference to FIGS. 6 to 9 together with FIGS. 1 to 5 described in the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 6 is a block configuration diagram of an electric motor control apparatus according to Embodiment 2 of the present invention. In FIG. 6, in the second embodiment, in addition to the configuration of the first embodiment, a phase control unit 6 that controls the energization phase of the driving unit 5 to control the rotation speed of the electric motor 2, and a spark determination unit 4. For example, an EEP-ROM that can electrically erase, write, and read the stored contents, and a timing time at which the A / D conversion means 33 samples (hereinafter referred to as sampling timing). And sampling setting means 8 for setting according to the energization phase.

  FIG. 7 is a diagram showing the detection waveform and detection timing of the spark detection means according to Embodiment 2 of the present invention. FIG. 7 (a) shows the current flowing through the motor 2 when there is no spark and is normal. In the waveform diagram detected by the current detection means 31, when the phase of the drive means 5 is controlled by the phase control means 6, when the energization phase is 0 ms (waveform A: broken line) and when the energization phase is 5 ms (waveform B: solid line) FIG. 7B is a waveform diagram in which the current detection means 31 detects the current flowing through the electric motor 2 when the spark is abnormal, and is full-wave rectified by the rectification means 32. The phase control means 6 is shown in FIG. FIG. 7C is a timing diagram of sampling in which the output of the rectifying unit 32 is detected by the A / D conversion unit 33. FIG. 8 is a characteristic diagram showing the relationship between the energization phase and the peak current phase in the second embodiment of the present invention. FIG. 9 is a diagram showing a second determination method of the spark determination means in the second embodiment of the present invention, and FIG. 9A shows the peak detected by the A / D conversion means 33 when the energization phase is 5 ms. FIG. 9B is a diagram showing current values. FIG. 9B shows a comparison with the spark abnormality determination level set in advance with respect to the change amount ΔI which is the difference between the maximum value and the minimum value of the peak current value detected in FIG. FIG.

  First, the storage means 7 stores the output of the spark determination means 4 when the motor 2 was last operated. The storage means 7 electrically writes the output of the spark determination means 4 that determines whether the state of the spark is normal or abnormal immediately before the power supply of the storage means 7 is shut off. When operating the electric motor 2, the phase control means 6 first reads the stored contents of the storage means 7 at the previous operation and confirms whether the state of the spark is normal or abnormal.

  The phase control means 6 starts the operation by controlling the electric motor 2 by the driving means 5 at an appropriate energization phase when the spark is normal, and a current flows through the electric motor 2 so that the electric motor 2 rotates. As shown in FIG. 7A, the detected waveform of the current detecting means 31 is the waveform A shown by the dotted line when the energizing phase of the phase control means 6 is 0 ms, and is shown by the solid line when the energizing phase is 5 ms. Waveform B is as follows.

  Since the waveform and operation until the spark determination means 4 finally determines whether the spark is normal or abnormal are the same as those in the first embodiment described above, the current of the motor 2 at the energization phase of 0 ms is detected. A detailed description of the operation is omitted here.

  Next, in order to control the rotation speed of the electric motor 2 to be low, for example, when the energization phase is 5 ms, the detection waveform of the current detection means 31 is the waveform B shown by the solid line in FIG. become that way. At this time, the time at which the current takes a peak value has a time difference of Δt between the energization phase of 0 ms and the energization phase of 5 ms. FIG. 7B shows a detection waveform obtained by rectifying the output of the current detection means 31 by the rectification means 32.

  As shown in FIG. 7B, the sampling timing of the A / D conversion means 33 that detects the digital value for the waveform after rectification of the waveform B is the peak value when the energization phase is 0 ms and when the energization phase is 5 ms. Therefore, since the time difference is Δt, the current waveform is the same as that when the energization phase is controlled at 0 ms. In the first embodiment, at a predetermined timing T2 that is later than the predetermined timing T1 by Δt from the zero cross of the commercial power supply voltage. It is necessary to sample. FIG. 7C shows the sampling timing of the A / D conversion means 33 at the predetermined timing T2 delayed by Δt in this way.

  As a result, the A / D conversion means 33 can sample at the peak value of the current. The output waveform of the A / D conversion means 33 after the sampling, the amount of change in the peak current value, and the spark abnormality determination are described above. It becomes the same as FIG. 4A to FIG. 4C in the first embodiment, and it is possible to determine whether the spark is normal or abnormal. In the first embodiment, a signal is directly given to the drive means 5 by the output of the spark determination means 4 to control the electric motor 2. However, in the second embodiment, the output of the spark determination means 4 is a phase. A signal is sent to the control means 6, and upon receiving the signal, the phase control means 6 outputs a spark abnormality to the drive means 5 that controls the electric motor 2 to control the electric motor 2.

  In the above description, it has been described that there is a time difference of Δt between the energization phase of 5 ms and the energization phase of 0 ms in the peak current of the electric motor 2. However, the rotational speed control of the electric motor 2 is only the energization phase of 5 ms. Not exclusively. FIG. 8 is an example showing the relationship with the phase at which the peak current is generated when the energization phase of the electric motor 2 is changed from 0 ms to 8 ms with the power supply frequency of 50 Hz as an example. The characteristics of the driving means 5 also differ.

  In FIG. 8, the peak current generation phase from the energization phase 0 ms to 4 ms is 5 ms, and there is no difference from the energization phase 0 ms, and Δt = 0. Therefore, the peak current can be detected at a predetermined timing T2 from the zero cross of the commercial power supply voltage for sampling by the A / D conversion means 33 in 5 ms. However, in the energization phase of 5 ms, the peak current generation phase is Δt = 1 ms and occurs at 6 ms. Therefore, the predetermined timing T2 needs to be performed at 6 ms. Hereinafter, at the energization phase of 6 ms, the predetermined timing T2 is 7 ms. As described above, the A / D conversion unit 33 can detect the peak current value by changing the predetermined timing T2 according to the energization phase.

  Since this energization phase is a known value determined in advance for controlling the electric motor 2, sampling may be performed at the timing T2 of the peak current generation phase based on the energization phase value shown in FIG. . The timing T2 for sampling in accordance with the value of the energization phase is measured in advance, and based on this, the timing for sampling is output from the sampling setting means 8 to the A / D conversion means 33.

  With such a configuration, the peak current value can be detected with high accuracy, and therefore it becomes possible to determine the abnormality of the spark in a wide energization phase of phase control for controlling the rotation speed of the electric motor 2. By controlling so that the power supply to 2 is cut off and the operation is stopped, smoke and ignition from the electric motor 2 when the spark is abnormal can be accurately prevented, and safety can be ensured.

  Further, when the energization phase is changed by phase control, the peak current value of the current value changes as shown in FIG. For this reason, it is preferable to have a plurality of spark abnormality determination levels in accordance with the energization phase to be controlled. In this way, it is possible to detect the occurrence of sparks with higher accuracy in accordance with the peak current value of the current value without being influenced by the controlled phase, and always accurately detect the occurrence of sparks in accordance with the controlled phase. Is possible.

  As described above, in the second embodiment, in addition to the effect of the first embodiment, when controlling by changing a wide energization phase in order to control the rotation speed of the electric motor 2, according to the energization phase, By setting the sampling timing, the sampling of the motor current can be detected with high accuracy, so that the spark abnormality can be determined more accurately. As a result, it is possible to provide a safe motor control device by preventing smoke and fire due to abnormal heating associated with abnormal sparks of the electric motor 2.

  Further, the output of the spark determination means 4 is written in the storage means 7, and the output information of the spark determination means 4 at the previous operation of the storage means 7 is read before the motor 2 is energized when starting the next operation, and the read contents By controlling the operation of the electric motor 2 based on the above, when the read content is the content of the spark abnormality, it is possible to prevent the re-operation without supplying the electric power to the electric motor 2. Therefore, it is possible to reliably prevent smoke and ignition due to abnormal heating caused by abnormal sparks from the electric motor 2, and to provide a safe motor control device.

  In the second embodiment, the case where the electric power is not supplied to the electric motor 2 when the content of the storage means 7 is abnormal during re-operation has been described. However, the present invention is not limited to this. The energization phase of the drive means 5 may be controlled so that the electric motor 2 is rotated at a rotational speed lower than the rotational speed and at which no abnormal spark occurs. In this way, in addition to the above effects, it is possible to prevent smoke and fire due to abnormal heating due to abnormal sparks from the electric motor 2 during re-operation, and to reduce the rotation speed of the electric motor 2 to the user It is possible to provide the electric motor control apparatus that can also use the electric motor 2 as a notification means of a spark abnormality and can notify the user of a spark abnormality without providing a new notification means. is there. Of course, in such a configuration, a display unit and a sound generation unit for notifying the user of a spark abnormality may be provided and separately notified. If comprised in this way, it will become possible to notify an apparatus abnormality reliably by a user.

  Further, the information stored in the storage means 7 when a spark abnormality is detected preferably includes spark detection information and the total operation time of the motor until spark detection. The most common cause of spark failure is often the motor brush being frayed. For this reason, when a spark abnormality is detected, the total operation time becomes one standard for determining the life of the motor and the end state of the brush. By storing the total operation time in this way, for example, when a request for repair is received from the user, the information can be read out from the storage means 7 for quick repair, and serviceability is improved. Further, such an effect is useful because only the information as described above is stored in the storage means 7 and the same effect can be obtained even when the motor is not stopped or powered down. .

  Further, in the second embodiment, in the determination method of the spark determination means 4, as in the first embodiment, the change amount between the current data value and the previous data value of the A / D conversion means 33 is determined as the spark abnormality determination level. However, the present invention is not limited to this, and the spark determination unit 4 is not limited to this, and the spark determination unit 4 determines the maximum and minimum values of the digital value sampled by the A / D conversion unit 33 within a predetermined time. A second determination method may be used in which a difference from the value is obtained, and when the obtained difference value is greater than a predetermined spark judgment level set in advance, it is determined that the spark is abnormal. For example, as shown in FIG. 9A, for the data values sampled by the A / D conversion means 33, the maximum value and the minimum value are obtained for the data values Ip1 to Ip6 within a predetermined time T3. For example, the maximum value = When Ip1 and minimum value = Ip5, as shown in FIG. 9B, a change amount ΔI = Ip1−Ip5, which is the difference between the maximum value and the minimum value, is obtained, and the difference within T3 within this predetermined time is obtained. Compared with a certain ΔI and a preset spark abnormality determination level, if the change amount ΔI is larger than the spark abnormality determination level, it is determined that the spark is abnormal, and a spark abnormality signal is output from the spark determination means 4. Similar effects can be obtained in such operations.

  In the second determination method described above, the spark determination means 4 compares the change amount ΔI between the maximum value and the minimum value within a predetermined time T3 once compared with a preset spark abnormality determination level. However, when it is large, the case where the determination result of the spark abnormality is output has been shown. However, instead of making a single determination at a predetermined time T3, a predetermined number of repetitions may be determined, and at a predetermined time T3. When the change amount ΔI continuously exceeds the spark abnormality determination level, or when the change amount ΔI exceeds the spark abnormality determination level within a predetermined number of repetitions of the predetermined time T3, The determination of spark abnormality may be finally output from the spark determination means 4.

In the first embodiment and the second embodiment described above, the spark determination unit 4 has compared the amount of change with a predetermined spark abnormality determination level to determine the abnormality of the spark. However, the present invention is not limited to this. ,
The spark determination means 4 may set a plurality of predetermined spark determination levels and determine the degree of abnormality of the spark in multiple stages. It goes without saying that finer control can be achieved by doing in this way.

  In the second embodiment, the determination result of the spark determination means 4 stored in the storage means 7 is read and the operation of the electric motor 2 is controlled. However, the present invention is not limited to this, and the spark determination means 4 determines a spark abnormality. Sometimes, for example, a current fuse or the like may be disconnected so that the commercial power supply 1 is not energized to the electric motor 2. Thereby, the storage means 7 can be omitted.

  Furthermore, in the second embodiment, the case where an EEP-ROM is used as the storage means 7 has been described. However, the present invention is not limited to this, and the commercial power supply is cut off even for a storage element that loses its memory when the power supply is cut off. However, it goes without saying that the same effect can be obtained by using a memory element in which power is not lost by supplying power with a battery or the like, or a latching relay capable of memorizing mechanically.

Embodiment 3 FIG.
In the present embodiment, the configuration and basic operation of the motor control device are the same as those in the first or second embodiment. In the present embodiment, different forms of the determination method for determining spark abnormality will be described in more detail. Hereinafter, the third embodiment will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected about the same part as each above-mentioned embodiment, and the description is abbreviate | omitted.

  10 and 12 are diagrams showing a determination method of another embodiment of the spark determination means in the third embodiment of the present invention, FIG. 11 is FIG. 10 and FIG. 13 is the maximum peak current value detected in FIG. FIG. 14 is a diagram for explaining a spark abnormality determination process by comparing a change amount ΔI that is a difference between the minimum value and a spark abnormality determination level set in advance, and FIG. It is a figure for demonstrating the determination process of a spark abnormality by comparing the variation | change_quantity (DELTA) I which is a difference of the minimum value with the preset spark abnormality determination level. In the present embodiment, one detection interval is set with a plurality of peak current values detected at a predetermined sampling timing as a set, the difference between the largest Max value and Min value in one detection interval is taken, and a spark is obtained. When a detection section determined to be abnormal occurs continuously a plurality of times, the spark abnormality is confirmed and the determination of the spark abnormality is confirmed.

  10 and 12, the current values detected at predetermined sampling timings are numbered 1 to 30 for easy explanation of the present embodiment. Samples 1 to 10 will be described as detection zone 1, 11 to 20 as detection zone 2, and 21 to 30 as detection zone 3. As shown in FIG. 10, when sampling in the detection section 1 is started, in this embodiment, the sample 1 is first stored as both the Max value and the Min value. Subsequently, when the sample 2 is detected, it is compared with the previously stored Max value and Min value, and if the value is larger than the Max value, the Max value is rewritten to the value of the sample 2 if smaller than the Min value. In the same procedure, when up to the sample 10 is measured in FIG. 10, the value of the sample 5 is held as the Max1 value and the value of the sample 3 is held as the Min1 value in the detection section 1. When the measurement of one detection section is completed, as shown in FIG. 11, the difference value between the Max value and the Min value in the detection section is calculated, and the difference value is compared with a preset spark determination threshold value. It is determined whether it is above or below the threshold. If it is equal to or greater than the threshold, a flag indicating that the threshold is equal to or greater than the threshold is set in the detection section. In FIG. 11, a circle is virtually written in the column above the threshold value.

  Next, in the detection section 2 shown in FIG. 10, the sample 11 is first stored as both the Max value and the Min value as described above. Subsequently, when the sample 12 is detected, it is compared with the previously stored Max value and Min value, and if the value is larger than the Max value, the Max value is rewritten to the value of the sample 12 if smaller than the Min value. Similarly, when the measurement is performed up to the sample 20, the value of the sample 19 is held as the Max2 value and the value of the sample 11 is held as the Min2 value in the detection section 2. When the measurement in the detection section 2 is completed, as shown in FIG. 11, the difference value between the Max value and the Min value in the detection section 2 is calculated, and the difference value is compared with a preset spark determination threshold value. It is then determined whether it is above or below the threshold. If it is equal to or greater than the threshold, a flag indicating that the threshold is equal to or greater than the threshold is set in the detection section.

  In this way, the threshold determination of the detection section is repeated by the same procedure, and when it is determined that the threshold is equal to or more than the threshold continuously in three detection sections as shown in FIG. 11, it is determined that a spark abnormality is detected for the first time. That is, as a result of detecting the state shown in FIG. 12, as shown in FIG. 13, for example, the determination in the detection sections 1 and 2 is not less than the threshold value, but in the detection section 3 the flag is not set due to the determination in excess of the threshold value Therefore, in the state of FIG. 12 and FIG. 13, it is processed that the spark abnormality is not detected, and the normal operation state is continued.

  That is, as shown in FIG. 14, in the plurality of detection sections, the detection sections 1 to 4 are not flagged in the detection section 2 by the determination of the threshold value or more. Although the determination is detected, since the detection interval is three consecutive and the flag is not set by the determination above the threshold, the spark abnormality is not fixed. In the state shown in FIG. 14, a determination flag or higher is set in the detection section 5 to determine a spark abnormality.

  As described above, by setting a plurality of peak current values as one set to be one detection section, it is possible to remove noise components satisfactorily and perform more accurate spark abnormality determination. In addition, the configuration that determines the spark abnormality when the detection interval is continuously detected more than the threshold value multiple times enables more accurate determination of the spark abnormality, and as a self-monitoring function to detect product defects The performance can be very stable. Further, in the present embodiment, since the operation can be performed if the storage means 7 capable of storing three detection sections in succession is provided, the present embodiment is configured using an inexpensive element. In addition to being able to be implemented, it is possible to store the operation information before the occurrence of a malfunction in a longer term than in the first or second embodiment described above, and to increase the amount of information at the time of abnormal operation it can.

  It should be noted that the determination of how many peak current values make one detection interval, the value of the spark determination threshold value, and how many times the detection interval is continuously detected, the spark abnormality is determined. There is a very close relationship with this part. That is, with regard to how many peak current values make one detection section as a set, for example, if the number is too small, the difference between the Max-Min values becomes difficult and the spark abnormality determination tends to be influenced by noise components. It is in. On the other hand, if the amount is too large, the detection will be delayed although sparks continue to occur. The same can be said for the spark determination threshold and how many times a detection interval in which a flag equal to or greater than the threshold is set is detected as a spark abnormality.

  Here, the value of the spark determination threshold value is preferably determined experimentally because it depends on the magnitude of electric power for operating the motor. In addition, as described in the above-described embodiment, it is desirable to determine an optimum threshold value for each energized phase when performing phase control. For the above-described reason, the number of times of sampling within one detection section is preferably 3 to 15 times, and more preferably 5 to 10 times, when operating with a normal 50 Hz to 60 Hz power source. . Furthermore, about how many times a detection interval in which a flag equal to or greater than the threshold is set is detected as a spark abnormality, about 2 to 4 times is desirable for the reason described above.

  Further, in the present embodiment, a configuration has been described in which a detection abnormality with a flag equal to or greater than the threshold value is continuously detected, and a spark abnormality is determined as a reference. A configuration may be employed in which the number of detection intervals in the set in which the spark determination threshold or more is detected is counted, and the spark abnormality is determined when the count number is a predetermined number or more. With such a configuration, there is a concern that the detection of the spark abnormality is slightly delayed, but it is possible to more reliably remove the noise component and to detect the spark abnormality stably and with high accuracy. In addition, by storing the information at the time of detecting the spark abnormality, it is possible to store an operation state of a longer term, and to further increase the amount of information at the time of abnormal operation.

  Note that the operation after the spark abnormality is confirmed in the present embodiment is similar to the above-described second embodiment than the configuration in which the electric power is not supplied to the electric motor 2 or the rotation speed when it is determined that the spark is normal. Since it is the same that the configuration in which the energization phase of the driving means 5 is controlled so as to rotate the electric motor 2 at a rotation speed that is low and does not cause an abnormal spark, the description is omitted. Even if the spark abnormality determination method of the present embodiment is used in the first or second embodiment, it can be applied without impairing the effects described in the above embodiments.

Embodiment 4 FIG.
FIG. 15 is a schematic configuration diagram of a vacuum cleaner according to Embodiment 4 of the present invention. The electric vacuum cleaner according to the fourth embodiment is equipped with the electric motor control device according to the first to third embodiments.

  In FIG. 15, the electric vacuum cleaner main body 101 incorporates an electric blower 102 as a power for sucking air together with dust, and a dust collection chamber 103 is provided on the upstream side of the electric blower 102. The electric blower 102 includes an electric motor 2 having a commutator and a brush, and a fan that is rotationally driven by the electric motor 2. The electric motor 2 is controlled by the electric motor control device of the first or second embodiment. Further, the vacuum cleaner main body 101 is provided with a hose unit 105 for the purpose of extension, and one end of a hose 106 constituting the hose unit 105 is detachably connected to the vacuum cleaner main body 101. The hand handle 108 is provided at the other end. An extension pipe 109 is detachably connected to the hand handle 108, and a floor suction tool 110 is detachably connected to the upstream side of the extension pipe 109, and the electric blower 102 is collected from the floor suction tool 110. A negative pressure suction air passage is formed up to the dust chamber 103, and an exhaust air passage is formed between the downstream side of the dust collection chamber 103 and an exhaust port (not shown).

  As described above, in the fourth embodiment, the electric motor control device according to the first to third embodiments is mounted, and the electric blower 102 including the electric motor 2 and the fan is controlled. Smoke and ignition due to abnormal heating due to sparks can be prevented, so smoke is not discharged into the cleaning room, so there is no contamination of the room with smoke, and unpleasant odors may be attached to the smoke. Therefore, it is possible to provide a highly safe vacuum cleaner related to a fire without impairing the hygiene of the room due to an abnormal spark and preventing the electric motor 2 from firing.

Embodiment 5. FIG.
FIG. 16 is a schematic configuration diagram of a hand dryer according to Embodiment 5 of the present invention. The hand dryer in the fifth embodiment is equipped with the motor control device in the first to third embodiments.

  In FIG. 16, a high-pressure air flow generation unit 202 is incorporated in the upper part of the main body box 201, and a processing space 203 is formed in the lower part of the main body box 201 so that a hand can be inserted into and removed from the high-pressure air flow generation unit 202. A water receptacle is provided, and a drain container 204 for receiving water from the water receptacle is provided below the water receptacle so that it can be inserted and removed from the front surface of the main body box 201. The high-pressure airflow generation unit 202 sucks air from the suction port 205, generates high-pressure air, and blows away moisture near the hand insertion port on the front surface of the processing space 203. 210 is blown downward. The high-pressure airflow generation unit 202 includes an electric motor 2 having a commutator and a brush, and a turbo fan that is rotationally driven by the electric motor 2, and the electric motor 2 is controlled by the electric motor control device of the first to third embodiments. Is done. In addition, the bottom of the treatment space 203 is configured as a water receiving portion having a drain hole 206, and is held inside the drain vessel 204 stored under the water receiving portion and detachably attached to the water guiding frame 207. The water receiving plate 208 is configured to have a flange 209 that overlaps the front edge of the water receiving plate 208 from above.

  As described above, in the fifth embodiment, by mounting the electric motor control device of the first to third embodiments and controlling the high-pressure airflow generation unit 202 including the electric motor 2 and the turbo fan, Smoke and ignition due to abnormal sparks caused by abnormal sparks of the electric motor 2 can be prevented, so that no flames are ejected and burned to the hand that has been inserted into the treatment space 203 to be dried, and should be dried. There was no smoke on the hand, no odor was attached to the hand, no smoke was sucked into the body, and no smoke or flames were coming out from the outlet, and the hand was trying to rush and dry Therefore, it is possible to provide a hand drying device that is not injured by hitting an unexpected place and has high fire-related safety, high safety against injury, and high hygiene.

It is a block block diagram of the electric motor control apparatus in Embodiment 1 of this invention. It is a wave form diagram which shows the commercial power supply waveform in Embodiment 1 of this invention. It is a wave form diagram which shows the detection waveform of the spark detection means in Embodiment 1 of this invention. It is a figure which shows the detection timing of the spark detection means in Embodiment 1 of this invention, and the operation | movement of a spark judgment means. It is a figure which shows the internal structure of the electric motor in Embodiment 1 of this invention, and the relationship between a spark and a motor current. It is a block block diagram of the electric motor control apparatus in Embodiment 2 of this invention. It is a figure which shows the detection waveform and detection timing of the spark detection means in Embodiment 2 of this invention. It is the characteristic view which showed the relationship between the energization phase and peak current phase in Embodiment 2 of this invention. It is a figure which shows the 2nd determination method of the spark determination means in Embodiment 2 of this invention. It is a figure which shows the judgment method of other embodiment of the spark judgment means in Embodiment 3 of this invention. FIG. 11 is a diagram for explaining a spark abnormality determination process by comparing a change amount ΔI that is a difference between a maximum value and a minimum value of a peak current value detected in FIG. 10 with a preset spark abnormality determination level. It is a figure which shows the judgment method of other embodiment of the spark judgment means in Embodiment 3 of this invention. FIG. 13 is a diagram for explaining a spark abnormality determination process by comparing a change amount ΔI that is a difference between a maximum value and a minimum value of a peak current value detected in FIG. 12 with a preset spark abnormality determination level. It is a figure for demonstrating the determination process of a spark abnormality by comparing with the preset spark abnormality judgment level about the variation | change_quantity (DELTA) I which is the difference of the maximum value of other peak current values, and a minimum value. It is a schematic block diagram of the vacuum cleaner in Embodiment 4 of this invention. It is a schematic block diagram of the hand dryer in Embodiment 5 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Commercial power supply, 2 Electric motor, 2a Motor stator winding, 2b Commutator, 2c Brush, 3 Spark detection means, 4 Spark judgment means, 5 Drive means, 6 Phase control means, 7 Storage means, 8 Sampling setting means, 31 Current detection means, 32 rectification means, 33 A / D conversion means, 101 vacuum cleaner body, 102 electric blower, 103 dust collection chamber, 105 hose unit, 106 hose, 107 connection part, 108 hand handle, 109 extension pipe, 110 Floor suction tool, 201 Main body box, 202 High-pressure air flow generator, 203 Processing space, 204 Drain container, 205 Suction port, 206 Drain hole, 207 Water guide frame, 208 Water receiving plate, 209 庇, 210 Air nozzle, Vs Commercial power supply voltage, Va spark voltage, Zm impedance, Im motor current.

Claims (20)

Drive means for controlling the operation of an electric motor having a commutator and a brush;
Spark detection means for detecting the occurrence of sparks generated in the electric motor at a predetermined sampling timing;
Spark determination means for determining an abnormality of the spark from the output of the spark detection means,
The motor control apparatus according to claim 1, wherein the driving unit controls the electric motor in accordance with an output of the spark determination unit. Drive means for controlling the operation of an electric motor having a commutator and a brush;
Spark detection means for detecting the occurrence of sparks generated in the electric motor at a predetermined sampling timing;
Spark determination means for determining an abnormality of the spark from the output of the spark detection means;
Phase control means for controlling the energization phase of the drive means;
Sampling setting means for setting the sampling timing of the spark detection means according to the energization phase,
The motor control apparatus according to claim 1, wherein the driving unit controls the electric motor in accordance with an output of the spark determination unit.   3. The motor control device according to claim 1, wherein the driving unit stops the operation of the electric motor when the spark determination unit determines that the spark is abnormal. The phase control means, when the spark determination means determines a spark abnormality,
3. The electric motor control according to claim 2, wherein the energization phase of the driving means is controlled so that the electric motor is rotated at a rotational speed lower than the rotational speed when the spark judgment means judges that the spark is normal. apparatus. Storage means for storing the determination result of the spark determination means;
The said drive means controls the driving | operation of the said motor according to the determination result of the said spark determination means memorize | stored in the said memory | storage means, when starting the driving | operation of the said motor. The electric motor control device according to any one of the above. When the determination result stored in the storage means is a spark abnormality, the drive means,
6. The electric motor control device according to claim 5, wherein operation of the electric motor is not started. The phase control means, when the determination result stored in the storage means is a spark abnormality,
Dependent on claim 2 or 4, wherein the energization phase of the drive means is controlled so that the electric motor is rotated at a rotational speed lower than the rotational speed when the spark judging means judges that the spark is normal. The electric motor control device according to claim 5.   The motor control device according to any one of claims 5 to 7, wherein an element that does not erase the stored contents even when power supply is cut off is used as the storage means.   9. The motor control apparatus according to claim 8, wherein an EEP-ROM capable of electrical erasure and electrical writing is used as the storage means.   The electric motor control device according to claim 1, wherein the spark detection unit detects an absolute value of a current supplied to the electric motor. The spark detection means includes
Current detecting means for detecting a current flowing through the motor;
Rectifying means for rectifying the output of the current detection means;
The motor control device according to claim 1, further comprising: an A / D conversion unit that samples an output of the rectifying unit as a digital value.   12. The A / D conversion means samples the current flowing through the electric motor a predetermined number of times with a phase difference of a predetermined time in synchronization with a cycle of a commercial power supply supplied to the electric motor. Electric motor control device.   13. The electric motor control device according to claim 12, wherein the A / D conversion means sets the phase difference of the predetermined time to a time that is ¼ of the cycle of the commercial power supply.   The electric motor control device according to claim 12 or 13, wherein the A / D conversion means sets the predetermined number of times to one time for each half cycle of the commercial power source.   The motor control device according to claim 11, wherein the A / D conversion unit samples the current flowing through the motor at a sampling timing set by the sampling setting unit.   The spark determination means obtains a difference between the current data and the previous data of the digital value sampled by the A / D conversion means, and when the obtained difference value is larger than a predetermined spark judgment level set in advance, the spark abnormality The electric motor control device according to claim 11, wherein the electric motor control device is determined.   The spark determination means obtains a difference between a maximum value and a minimum value within a predetermined time of the digital value sampled by the A / D conversion means, and the obtained difference value is larger than a preset predetermined spark judgment level. The motor control device according to any one of claims 11 to 15, wherein it is determined that the spark is abnormal.   The electric motor control device according to claim 16 or 17, wherein the spark determination means sets a plurality of the predetermined spark determination levels and determines the degree of abnormality of the spark in multiple stages. An electric motor having a commutator and a brush;
An electric vacuum cleaner comprising the electric motor control device according to claim 1. An electric motor having a commutator and a brush;
A hand dryer comprising the electric motor control device according to claim 1.

Images