JP2009236594A - Connection abnormality detection device and domestic electric instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection abnormality detection device and a domestic electric instrument can detect a connection abnormality with high detection accuracy by an inexpensive constitution, and controlling a load to prevent emission of smoke or fire caused by abnormal overheating when a connection abnormality is generated. <P>SOLUTION: This device is equipped with a driving means 6 for controlling operation of a motor 3 connected electrically to a commercial power source 1 through a connection part 2; a connection abnormality detection means 4 for detecting a current flowing in the connection part 2 at a sampling timing; and a connection abnormality determination means 5 for detecting generation of a spark generated at the connection part 2 from output from the connection abnormality detection means 4, and determining an abnormality of a connection state. The driving means 6 controls operation of the motor 3 corresponding to output from the connection abnormality determination means 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a connection abnormality detection device that detects a connection state of a connection portion that electrically connects a power source and a load, and a home appliance including the connection abnormality detection device.

  For example, in a conventional electronic device including a plurality of printed boards on which circuit components are soldered and mounted, a dummy component that does not affect the circuit operation of the circuit components on each of the plurality of printed boards. In other words, the stress applied to the soldered portion of the dummy component is stricter than the stress applied to the soldered portion of the circuit component (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2005-109084 (Claim 5)

  When a connection abnormality (hereinafter also referred to as “bad connection”) occurs in a connection portion such as a terminal block, a connector, or a soldered portion on a printed circuit board, heat generation or spark (hereinafter also referred to as “spark”) due to the bad connection occurs. ) May occur, causing smoke and fire from the connection. For this reason, a connection abnormality detection device that can accurately detect the occurrence of a bad connection is desired.

  Conventionally, as a means of diagnosing deterioration of a soldered portion, a resistor is soldered and mounted on a printed circuit board on which a circuit component is soldered and mounted as a dummy component that does not affect the circuit operation of the circuit component. It has been proposed that the stress applied to the soldering portion is configured to be stricter than the stress applied to the soldering portion of the circuit component to diagnose deterioration of the soldering portion. However, in this configuration, it is necessary to secure a component cost for mounting a component unnecessary for circuit operation and a board area for mounting the component, resulting in a problem that the mounting board cost increases. It was.

  In addition, the fact that the soldered part has deteriorated is detected using dummy parts, and the failure status of the deteriorated soldered part is not directly used, so the connection state detection accuracy is low. was there.

  In addition, the conventional configuration has a problem that it is impossible to detect the connection state of connection parts (terminal blocks, connectors, etc.) other than the soldering part on the printed circuit board.

  The present invention has been made to solve the above-described problems, and can detect a connection abnormality with a high detection accuracy and an inexpensive configuration. Also, when a connection abnormality occurs, an abnormal overheating occurs. An object of the present invention is to provide a connection abnormality detection device and a home electric appliance capable of controlling a load so as to prevent smoke generation and ignition due to fire.

  The connection abnormality detection device according to the present invention includes a drive unit that controls operation of a load that is electrically connected to a power source via a connection unit, and a connection abnormality detection that detects a current flowing through the connection unit at a predetermined sampling timing. Means for detecting the occurrence of a spark generated at the connecting portion from the output of the connection abnormality detecting means, and determining a connection abnormality, and the drive means outputs the connection abnormality determining means. The operation of the load is controlled according to the above.

  According to the present invention, it is possible to realize a connection abnormality detection with a high detection accuracy and an inexpensive configuration by determining a connection state abnormality occurring in the connection portion and controlling the operation of the load according to the determination. In addition, the load can be controlled so as to prevent smoke and ignition due to abnormal overheating when a connection abnormality occurs.

Embodiment 1 FIG.
FIG. 1 is a block configuration diagram of a connection abnormality detection device according to Embodiment 1 of the present invention. In FIG. 1, the connection abnormality detection device is composed of a connection abnormality detection unit 4, a connection abnormality determination unit 5, and a drive unit 6, and is a load that is electrically connected to the commercial power source 1 via the connection unit 2. The operation of a certain motor 3 is controlled. Further, the connection abnormality detection means 4 includes a current detection means 41 for detecting a current supplied to the electric motor 3 through the connection portion 2, a rectification means 42 for rectifying the output of the current detection means 41, and a rectification means 42. And A / D conversion means 43 for detecting the output as a digital value. Further, the connection abnormality determination unit 5 determines an abnormality in the connection state of the connection unit 2 from the detection result of the A / D conversion unit 43 and outputs the determination result to the drive unit 6. The drive means 6 is composed of, for example, a triac or the like, and controls the electric motor 3 based on the output of the connection abnormality determination means 5.

  The connecting portion 2 is provided for electrically connecting the commercial power source 1 and the motor 3 by the terminals 21 and 22, such as a terminal block, a connector, a flat terminal, a closed end connector, a solder joint, etc. Composed.

In the first embodiment, as shown in FIG. 1, the connecting portion 2 for connecting the electric motor 3 will be described. However, the present invention is not limited to this, and the driving means 6 and the connection abnormality detecting means 4 are mounted. The present invention can also be applied to solder joints on printed circuit boards and other connection parts to which power from the commercial power source 1 is supplied.
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 connection abnormality detecting means in the first embodiment of the present invention, and FIG. FIG. 3B is a waveform diagram in which the current detection means 41 detects the current flowing in the connection section 2 when no connection abnormality has occurred, and FIG. 3B shows the current flowing in the connection section 2 in the case of a connection abnormality. FIG. 3C is a waveform diagram in which the output of the current detection means 41 is rectified by the rectification means 42. FIG. 4 is a diagram showing the detection timing of the connection abnormality detecting means and the operation of the connection abnormality determining means in Embodiment 1 of the present invention. FIG. 4 (a) shows the output of the rectifying means 42 by the A / D conversion means 43. FIG. 4B shows the detected value obtained by detecting the output of the rectifier 42 by the A / D converter 43, and FIG. 4C shows the current data of the detected value of the A / D converter 43. FIG. 4D is a diagram showing the amount of change, which is the absolute value of the difference from the previous data, and the connection abnormality judgment level of the connection abnormality judgment means 5, FIG. 4D is a diagram showing the judgment result of the connection abnormality judgment means 5, FIG. These are figures which show the driving | running state of the electric motor 3 which the drive means 6 controls by the determination result of the connection abnormality determination means 5. FIG. Further, FIG. 5 is a diagram showing the configuration of the connecting portion and the relationship between the spark and the load current in Embodiment 1 of the present invention. FIG. 5 (a) shows the magnitude of the spark generated at the connecting portion 2 and the load current. FIG. 5B is a schematic diagram showing the relationship between the spark voltage Va and the load current Im.

  First, when the electric motor 3 is not driven, a spark is not generated in the connecting portion 2 and therefore the connection abnormality determining means 5 determines that the connection is normal, and the driving means 6 changes the commercial power supply voltage shown in FIG. 3 and the electric motor 3 starts operation. The detected waveform of the current detection means 41 when the connection state after the start of operation is normal is a waveform as shown in FIG. 3A. When a spark is generated at the connection part 2 due to a bad connection of the connection part 2, a spark is generated. The voltage applied to the motor 3 is reduced and the load current (motor current) flowing to the motor 3 via the connecting portion 2 is also reduced. The detected waveform of the current detection means 41 is shown in FIG. )become that way. In this phenomenon, since the spark is unstable, the voltage drop acting on the motor 3 is also unstable, and as a result, the load current is also unstable. Such a phenomenon will be described in more detail with reference to FIG.

  A case where a bad connection occurs at the terminal 21 of the connection unit 2 in FIG. The relationship between the spark voltage Va of the spark generated by the bad connection of the terminal 21 and the load current Im flowing through the electric motor 3 is as follows: the voltage of the commercial power source 1 is Vs, and the impedance of the connecting portion 2 and the electric motor 3 is Z. Since the spark voltage at 21 is Va, it can be regarded as Im = (Vs−Va) / Z. Here, for the sake of convenience, assuming that Z does not change in magnitude due to the occurrence of a spark, the load current Im1 flowing through the electric motor 3 when no spark is generated is the spark voltage Va = 0 (zero). = Vs / Z. However, since a spark voltage Va is generated when a spark occurs, if the current flowing through the electric motor 3 at this time is Im2, Im2 = (Vs−Va) / Z. Since Va is equal to or larger than 0, when considering the load 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 formula representing the load current Im flowing in the electric motor 3, the load current Im is proportional to the magnitude of the spark as a result. Will also change.

  The relationship between the spark voltage Va and the load 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 load current Im. It acts like a variable. That is, when the peak current of the load 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 load current Im unstable. Furthermore, in the bad connection state, the contact state of the terminal 21 is also unstable, so that the contact resistance value is also unstable, and the load current is also unstable due to this influence. That is, it is possible to determine the occurrence of a spark due to a connection abnormality based on the amount of change in the peak value of the load 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 41 for detecting the load current is, for example, full-wave rectified by a rectifier 42 by a diode bridge (not shown) or the like as shown in FIG. . The A / D converter 43 samples the output of the rectifier 42 a predetermined number of times with a phase difference of a predetermined time in synchronization with the cycle of the commercial power supply 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 42 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 43 in this way are as shown in FIG.

  Next, as shown in FIG. 4C, the connection abnormality determination unit 5 calculates the 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 unit 43. This is repeated sequentially. At this time, the connection abnormality determination means 5 compares the obtained change amount with a predetermined connection abnormality determination level set in advance, and determines that there is a connection abnormality when the change amount exceeds the connection abnormality determination level. . The connection abnormality determination level varies depending on the load (electric motor 3) and also varies depending on the operating state of the load. Therefore, it is preferable to set the connection abnormality determination level based on an experimental value obtained by measuring an actual change amount when a spark is generated.

  FIG. 4D shows a detection example of the connection abnormality determination means 5 determined at the connection abnormality determination level with respect to the current change amount of FIG. 4C. The connection abnormality determination means 5 is shown in FIG. Since the current change amounts ΔI1 to ΔI4 in c) are lower than the connection abnormality determination level, it is determined that the connection is normal. However, since the current change amount ΔI5 is higher than the connection abnormality determination level, it is determined that the connection is abnormal, and the driving means 6 The judgment result is output for.

  The drive unit 6 controls the electric motor 3 based on the output of the connection abnormality determination unit 5. The control of the electric motor 3 is performed so that, for example, the power supply to the electric motor 3 is cut off and the operation is stopped so that safety can be ensured without causing smoke or ignition from the connecting portion 2. 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 3, 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 connection abnormality is detected in this way, in the configuration in which the control is performed with a method with a small supply power, the detection of the spark is continued in the subsequent operation state, and further connection abnormality is detected. In this case, the power supply may be reduced stepwise so as to control with smaller power, and if the connection abnormality is still detected, the power supply may be cut off. 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 due to a bad connection generated in the connection unit 2 to determine an abnormality in connection, and to control the operation of the electric motor 3 according to this determination. According to the present embodiment, the detection of the occurrence of sparks can be realized with a high detection accuracy and an inexpensive configuration by sampling twice in one cycle, and due to abnormal overheating when a connection abnormality occurs. The load can be controlled to prevent smoke and fire.

  Further, by detecting the load current flowing through the electric motor 3 through the connection unit 2 and sampling the output obtained by rectifying the detected load current as a digital value, a high-pass filter or the like for extracting a noise component becomes unnecessary. Further, it is possible to prevent erroneous determination of occurrence of sparks by measuring external noise, and detection of occurrence of sparks can be realized with a high detection accuracy and an inexpensive configuration. Therefore, it is possible to provide a connection abnormality detection device that is extremely simple, has a small number of parts, is inexpensive, has high reliability, and can prevent smoke and fire due to connection abnormality.

  Further, in the sampling of the load current, the 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 so as to sample the load current value at a predetermined phase angle. No need for high-speed A / D conversion or data processing, A / D converter with general conversion speed or microcomputer with general data processing speed can be used. It is possible to provide a connection abnormality detection device that can prevent smoke and ignition due to abnormality.

  Further, the connection abnormality determination means 5 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 means 43, and the obtained amount of change and the connection abnormality judgment level. Therefore, it is determined that the connection is abnormal. Therefore, an integration means for adding a small amount of detection values and accumulating them becomes unnecessary, and detection of spark generation can be realized with an inexpensive configuration. Accordingly, it is possible to provide a connection abnormality detection device that can prevent smoke and fire due to a connection abnormality with an inexpensive configuration.

  In addition, when the connection abnormality determination unit 5 determines that there is a spark abnormality, the drive unit 6 is configured to control so that the power supply to the motor 3 is cut off and the operation is stopped, so that the connection abnormality is prevented. It is possible to provide a connection abnormality detection device that can stop the operation of the electric motor 3 when it occurs and can prevent smoke and fire due to a connection abnormality.

  In the first embodiment, the case where the load current is detected for each zero cross of 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.

  Further, in the first embodiment, the predetermined timing T1 for A / D converting the output of the rectifying means 42 for measuring the load 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 current data value after A / D conversion of the load 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 means 41 is sampled by the A / D conversion means 43 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 43 or the rear stage of the current detection means 41. 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.

  Further, in the first embodiment, the digital value is detected by the A / D conversion means 43 after the output of the current detection means 41 is rectified by the rectification means 42, but the electronic circuit is appropriately provided without providing the rectification means 42. Even if the output of the current detection means 41 is directly detected by the A / D conversion means 43 by designing the data or appropriately processing the detection value of the A / D conversion means 43, the same effect can be obtained. Needless to say.

  Furthermore, in the first embodiment, the case where the rectifying means 42 performs full-wave rectification using a diode bridge or the like has been described. However, if the sampling timing of the A / D conversion means 43 is appropriate even in a 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.

  Furthermore, in the first embodiment, in the determination of the connection abnormality determination unit 5, the amount of change between the current data value and the previous data value of the A / D conversion unit 43 is compared with the connection abnormality determination level, thereby Although the case of determining an abnormality has been described, the present invention is not limited to this, and the difference between the maximum value and the minimum value within a predetermined time of the digital value sampled by the A / D conversion means 43 is obtained. A determination method may be used in which it is determined that the connection is abnormal when the predetermined spark determination level is set. Similar effects can be obtained in such operations.

  Furthermore, in the first embodiment, when the connection abnormality determination unit 5 determines that the amount of change between the current data value and the previous data value of the A / D conversion unit 43 is larger than the connection abnormality determination level even once. However, the present invention is not limited to this. However, the present invention is not limited to this, and the case where the connection abnormality determination level is continuously exceeded within the predetermined time or the connection abnormality determination level is exceeded is predetermined. When there is a number of times, a connection abnormality determination may be output.

  Further, in the first embodiment, the case where the connection abnormality determination unit 5 determines the connection abnormality by comparing the amount of change with a predetermined connection abnormality determination level has been described. The means 5 may set a plurality of predetermined connection abnormality determination levels and determine the degree of abnormality of the connection portion in multiple stages. It goes without saying that further control can be performed by carrying out in this way.

  Furthermore, in the first embodiment, a case has been described in which the connection abnormality determination means 5 determines the connection abnormality using the amount of change between the current data value and the previous data value of the A / D conversion means 43. However, the present invention is not limited to this, and the connection abnormality determination unit 5 determines that a connection abnormality has occurred when the digital value sampled by the A / D conversion unit 43 is smaller than a predetermined connection abnormality determination level set in advance. Also good.

Embodiment 2. FIG.
In the second embodiment, a mode including a storage unit that stores the determination result of the connection abnormality determination unit 5 will be described. Hereinafter, the second embodiment will be described with reference to FIG. 6 with a focus on differences from 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 diagram of a connection abnormality detection device according to Embodiment 2 of the present invention. In FIG. 6, in the second embodiment, in addition to the configuration of the first embodiment, for example, an EEP-ROM that can electrically read / write and erase stored contents is used. Is stored.

  The storage unit 7 is electrically written with a determination result as to whether or not the connection state of the connection unit 2 when the motor 3 was last operated is normal immediately before the storage unit 7 is powered off. When the electric motor 3 is operated again, the connection abnormality determination means 5 first reads the stored contents of the storage means 7 at the previous operation, determines whether the connection state is normal or abnormal, and the drive means. 6 is output.

  The drive unit 6 controls the electric motor 3 based on the output of the connection abnormality determination unit 5. That is, when the determination result at the previous operation stored in the storage unit 7 is abnormal, the drive unit 6 does not start the operation of the electric motor 3. On the other hand, when the connection is normal, the motor 3 is controlled by the driving means 6 to start the operation. A current flows through the motor 3 and the motor 3 rotates. Thereafter, the waveform and the operation until the current of the connection unit 2 is detected and finally the connection state is determined to be normal are the same as those in the first embodiment described above. Omit.

  As described above, in the second embodiment, in addition to the effects of the first embodiment, the output of the connection abnormality determining means 5 is written in the storage means 7 and before the motor 3 is energized when starting the next operation. When the output information of the connection abnormality determination means 5 at the previous operation of the storage means 7 is read and the operation of the electric motor 3 is controlled based on the read contents, The re-operation of the electric motor 3 can be prevented. As a result, it is possible to provide a connection abnormality detection device that can prevent smoke and fire due to abnormal heating accompanying a connection abnormality.

  In the second embodiment, the description has been given of the case where the electric power is not supplied to the electric motor 3 when the content of the storage means 7 is abnormal during re-operation. However, the present invention is not limited to this. The electric motor 3 may be controlled to rotate at a rotational speed lower than the rotational speed. In this way, in addition to the above effects, the motor 3 can also be used as a notification means for a connection abnormality to the user due to a decrease in the rotation speed of the motor 3, and a new notification means is provided. Without providing, it is possible to notify the user of the connection abnormality.

  Furthermore, in the second embodiment, the determination result of the connection abnormality determination means 5 stored in the storage means 7 is read to control the operation of the motor 3. However, the present invention is not limited to this, and the connection abnormality determination means 5 detects the connection abnormality. When the determination is made, for example, a current fuse or the like may be disconnected, and the commercial power supply 1 may not be energized to the electric motor 3. 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. Needless to say, the same effect can be obtained by using a memory element that can store power by supplying power, or a latching relay that can memorize mechanically.

Embodiment 3 FIG.
In the present embodiment, the configuration and basic operation of the connection abnormality detection device are the same as those in the first or second embodiment. In the present embodiment, different modes of the determination method for determining a connection 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.

  7 and 9 are diagrams showing a determination method according to another embodiment of the connection abnormality determination means in the third embodiment of the present invention, FIG. 8 is FIG. 7 and FIG. 10 is the maximum peak current value detected in FIG. FIG. 11 is a diagram for explaining the connection abnormality determination process by comparing the change amount ΔI, which is the difference between the value and the minimum value, with a preset connection abnormality determination level, and FIG. 11 shows another maximum peak current value. FIG. 6 is a diagram for explaining a connection abnormality determination process by comparing a change amount ΔI that is a difference between and a minimum value with a connection abnormality determination level set in advance. In the present embodiment, one detection section is set with a plurality of peak current values detected at a predetermined sampling timing as a set, and the difference between the largest Max value and the smallest Min value in one detection section. The detection of the connection abnormality is confirmed by determining the connection abnormality when the detection section determined to be the connection abnormality occurs a plurality of times continuously.

  7 and 9, the current values detected at a predetermined sampling timing 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. 7, 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 the sample 10 is measured in FIG. 7, 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. 8, 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 abnormality 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. 8, a circle is virtually entered in the column above the threshold value.

  Next, in the detection section 2 shown in FIG. 7, 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. When the value is larger than the Max value, the Max value is rewritten to the value of the sample 12 when 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. 8, 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 abnormality 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.

  Thus, the threshold determination of the detection section is repeated by the same procedure, and when it is determined that the detection threshold is equal to or greater than the threshold in three detection sections as shown in FIG. 8, it is determined that a connection abnormality is detected for the first time. That is, as a result of detecting the state as shown in FIG. 9, for example, a determination that is equal to or greater than the threshold is performed in detection sections 1 and 2 as illustrated in FIG. Therefore, in the state of FIGS. 9 and 10, it is processed that the connection abnormality is not detected, and the normal operation state is continued.

  That is, as shown in FIG. 11, 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, the connection abnormality is not fixed because there are three consecutive detection sections and the determination flag is not higher than the threshold. In the state as shown in FIG. 11, a determination flag or more is set in the detection section 5 to establish a connection abnormality.

  In this way, 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 connection abnormality determination. In addition, it is possible to make a connection abnormality determination with higher accuracy by the configuration that establishes a connection abnormality when the detection interval is continuously detected more than a threshold value more than once, and it can be used 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 section, the value of the abnormality determination threshold value, and how many times the threshold value is continuously detected in the detection section determine connection abnormality. There is a very close relationship with this part. That is, with respect 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 connection 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 abnormality 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 connection abnormality.

  Here, the value of the abnormality determination threshold value is preferably determined experimentally because it depends on the magnitude of electric power for operating the electric motor 3 and the like. 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 the detection interval in which a flag equal to or greater than the threshold is set is detected continuously, the connection abnormality is determined to be about 2 to 4 times for the reason described above.

  Further, in the present embodiment, a configuration has been described in which a connection abnormality is determined based on how many times a detection interval with a flag equal to or greater than the threshold value is continuously detected. A configuration may be employed in which the number of detection intervals in the set in which the abnormality determination threshold or more is detected is counted, and the connection abnormality is determined when the count number is a predetermined number or more. With such a configuration, there is a concern that connection abnormality detection may be slightly delayed, but noise components can be removed more reliably, and connection abnormality can be detected stably with high accuracy. Further, by storing the information at the time of detecting the connection 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.

  As for the operation after the connection abnormality is confirmed in the present embodiment, the configuration in which power is not supplied to the motor 3 or the rotation speed when it is determined that the connection is normal is the same as in the first or second embodiment. Since it is the same that it can be configured to control the electric motor 3 to rotate at a lower rotational speed, the description thereof is omitted. Even if the connection 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.
In the fourth embodiment, a mode for notifying a user of a connection abnormality will be described. Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from 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. 12 is a block diagram of a connection abnormality detection device according to Embodiment 4 of the present invention. In FIG. 12, in the fourth embodiment, in addition to the configuration of the first embodiment, for example, a liquid crystal display element or the like is used. Is provided with a transmission means 8 for informing the user. Further, the connection abnormality determination means 5 of the fourth embodiment detects a spark generation level from the output of the connection abnormality detection means 4, determines the degree of abnormality of the connection state based on this spark generation level, and transmits the transmission means 8. The judgment result is output to.
Next, the operation of the fourth embodiment will be described with reference to FIG.

FIG. 13 is a diagram showing the detection timing of the connection abnormality detecting means and the operation of the connection abnormality determining means in Embodiment 4 of the present invention. FIG. 13A is a diagram showing the amount of change that is the absolute value of the difference between the current data and the previous data of the detection value of the A / D conversion means 43, and the judgment level of the connection abnormality judgment means 5, and FIG. It is a figure which shows the connection abnormality judgment result of the connection abnormality judgment means 5.
The connection abnormality detection means 4 detects the load current at a predetermined sampling timing by the A / D conversion means 43 as in the first embodiment. Then, as shown in FIG. 13A, the connection abnormality determination means 5 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 means 43. This is repeated sequentially. At this time, the connection abnormality determination means 5 compares the obtained change amount with a predetermined determination level set in advance, and when the change amount exceeds the determination level, the connection abnormality determination means 5 connects according to the determination level. Determine the degree of abnormal condition. Since the judgment level varies depending on the load (the electric motor 3), it is preferable to set it based on an experimental value obtained by measuring an actual change amount.

  As shown in FIG. 13 (b), the connection abnormality determination means 5 has a change amount smaller than the determination level, that is, the spark generation level is small, until the current change amounts ΔI1 to ΔI3 in FIG. 13 (a). 2 is determined to be normal. On the other hand, in the current change amounts ΔI4 to ΔI6, the current change amount is larger than the determination level, that is, the spark generation level is large, and a predetermined abnormality level (for example, an abnormality 1 to 1) according to the determination levels 1 to 3 exceeding the change amount. It is determined that abnormality 3). Then, based on the output of the connection abnormality determination means 5, for example, when the determination level is determined to be a predetermined level (for example, abnormality 3), the drive means 6 cuts off the power supply to the motor 3 and operates. Control to stop.

  When the connection abnormality determination unit 5 determines the abnormality level of the determination level (for example, abnormality 1 to abnormality 3), the transmission unit 8 provides information on the determined abnormality level (for example, attention) to the liquid crystal display element, for example. , Warning, shutdown, etc.). In this display, information on predetermined maintenance contents (for example, a message for prompting parts replacement) may be displayed.

  As described above, in the fourth embodiment, in addition to the effects of the first embodiment, the degree of connection abnormality of the connection unit 2 is determined based on the detected spark level, and the abnormality of the connection state is determined according to this determination. Information on the degree can be notified to the user.

  Further, when the operation of the electric motor 3 is interrupted, information is displayed on the transmission means 8, so that it is possible to notify the user why the operation has stopped.

  In the fourth embodiment, the case where the operation of the electric motor 3 is controlled based on the output of the connection abnormality determining means 5 has been described. However, the present invention is not limited to this and is transmitted without controlling the operation of the electric motor 3. Only the display on the means 8 may be performed.

  In the fourth embodiment, the case where a liquid crystal display element or the like is used as the transmission means 8 has been described. However, the present invention is not limited to this, and is based on a display element constituted by LEDs or the sound of a speaker or the like. But it ’s okay.

Embodiment 5 FIG.
FIG. 14 is a schematic configuration diagram of a vacuum cleaner according to Embodiment 5 of the present invention. The vacuum cleaner which is a household electrical appliance in this Embodiment 5 mounts the connection abnormality detection apparatus of said Embodiment 1-4.

  In FIG. 14, 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 3 and a fan that is rotationally driven by the electric motor 3. The electric motor 3 is connected to the commercial power source 1 via the connection part 2 of the first to fourth embodiments, and the connection state of the connection part 2 is detected by the connection abnormality detection device (not shown). 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 fifth embodiment, the connection abnormality detection device of the first to fourth embodiments is mounted, and the control of the electric blower 102 including the electric motor 3 and the fan and the connection state of the connection unit 2 are performed. By performing the detection, it is possible to prevent abnormal heating, smoke generation and ignition associated with the connection abnormality of the connection part 2 connecting the electric motor 3 and the commercial power source 1, and provide a highly safe vacuum cleaner related to fire. can do. In addition, by preventing smoke and ignition, smoke is not discharged into the cleaning room, so that the room is not polluted with smoke, and unpleasant odors do not adhere to smoke, so connection abnormalities Therefore, the hygiene in the room is not impaired.

  In addition, in this Embodiment, although the vacuum cleaner was demonstrated as an example of household appliances, this invention is not restricted to this, If it is household appliances which have the load connected to the power supply via the connection part 2 For example, a hand dryer may be used.

It is a block block diagram of the connection abnormality detection 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 connection abnormality detection means in Embodiment 1 of this invention. It is a figure which shows the detection timing of the connection abnormality detection means and operation | movement of a connection abnormality judgment means in Embodiment 1 of this invention. It is a figure which shows the structure of the connection part in Embodiment 1 of this invention, and the relationship between a spark and load current. It is a block block diagram of the connection abnormality detection apparatus in Embodiment 2 of this invention. It is a figure which shows the determination method of other embodiment of the connection abnormality determination means in Embodiment 3 of this invention. FIG. 8 is a diagram for explaining a connection abnormality determination process by comparing a change amount ΔI which is a difference between a maximum value and a minimum value of a peak current value detected in FIG. 7 with a preset connection abnormality determination level. It is a figure which shows the determination method of other embodiment of the connection abnormality determination means in Embodiment 3 of this invention. FIG. 10 is a diagram for explaining a connection 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. 9 with a connection abnormality determination level set in advance. It is a figure for demonstrating the determination process of a connection abnormality, comparing the variation | change_quantity (DELTA) I which is the difference of the maximum value of other peak electric current values with the connection abnormality judgment level set beforehand. It is a block block diagram of the connection abnormality detection apparatus in Embodiment 4 of this invention. It is a figure which shows the detection timing of the connection abnormality detection means and operation | movement of a connection abnormality determination means in Embodiment 4 of this invention. It is a schematic block diagram of the vacuum cleaner in Embodiment 5 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Commercial power source, 2 connection part, 3 motor, 4 connection abnormality detection means, 5 connection abnormality judgment means, 6 drive means, 7 memory | storage means, 8 transmission means, 21 terminal, 22 terminals, 41 current detection means, 42 rectification means, 43 A / D conversion means, 101 vacuum cleaner main body, 102 electric blower, 103 dust collecting chamber, 105 hose unit, 106 hose, 107 connection part, 108 hand handle, 109 extension pipe, 110 floor suction tool, Vs commercial power supply Voltage, Va spark voltage, Z impedance, Im load current.

Claims (21)

Drive means for controlling the operation of a load electrically connected to the power supply via the connection;
A connection abnormality detecting means for detecting a current flowing through the connection portion at a predetermined sampling timing;
A connection abnormality determining means for detecting the occurrence of a spark generated at the connection portion from the output of the connection abnormality detecting means, and determining an abnormality in the connection state;
The connection abnormality detection device, wherein the drive means controls the operation of the load according to the output of the connection abnormality judgment means.   2. The connection abnormality detection device according to claim 1, wherein the drive means stops the operation of the load when the connection abnormality determination means determines an abnormality in the connection state. Storage means for storing the determination result of the connection abnormality determination means,
3. The driving means controls the operation of the load according to a determination result of the connection abnormality determination means stored in the storage means when starting the operation of the load. 4. The connection abnormality detection device described. If the determination result stored in the storage means is a connection abnormality, the drive means,
The connection abnormality detection device according to claim 3, wherein the operation of the load is not started.   5. The connection abnormality detection device according to claim 3, wherein an element that does not erase the stored contents even when power supply is cut off is used as the storage means.   6. The connection abnormality detection device according to claim 5, wherein an EEP-ROM capable of electrical erasure and electrical writing is used as the storage means.   The connection abnormality detection device according to claim 1, further comprising a transmission unit that notifies information related to a connection state abnormality determined by the connection abnormality determination unit. A connection abnormality detecting means for detecting a current flowing in a connection portion for electrically connecting a power source and a load at a predetermined sampling timing;
A connection abnormality determining means for detecting an occurrence of a spark generated in the connection portion from an output of the connection abnormality detecting means, and determining an abnormality in a connection state;
A connection abnormality detection apparatus comprising: a transmission unit that notifies information related to a connection state abnormality determined by the connection abnormality determination unit. The connection abnormality determination means detects a spark generation level from the output of the connection abnormality detection means, determines the degree of abnormality of the connection state based on the spark generation level,
The connection abnormality detection device according to claim 7 or 8, wherein the transmission unit notifies predetermined information according to an abnormality degree determined by the connection abnormality determination unit.   The connection part is at least one of a terminal block, a connector, a flat terminal, a closed-end connector, and a solder joint provided to electrically connect the power source and the load. Item 10. The connection abnormality detection device according to any one of items 1 to 9.   The connection abnormality detection device according to claim 1, wherein the connection portion is a solder joint on a printed circuit board on which at least one of the driving unit and the connection abnormality detection unit is mounted. .   The connection abnormality detection device according to claim 1, wherein the connection abnormality detection unit detects an instantaneous value of a current supplied to the connection unit. The connection abnormality detecting means is
Current detecting means for detecting a current flowing through the connecting portion;
Rectifying means for rectifying the output of the current detection means;
The connection abnormality detection device according to claim 1, further comprising: an A / D conversion unit that samples the output of the rectification unit as a digital value.   14. The A / D conversion unit samples the current flowing through the connection portion a predetermined number of times with a phase difference of a predetermined time in synchronization with a cycle of power supplied to the load. Connection abnormality detection device.   15. The connection abnormality detection device according to claim 14, wherein the A / D conversion means sets the phase difference of the predetermined time to a time that is 1/4 of the cycle of the power source.   16. The connection abnormality detection device according to claim 14 or 15, wherein the A / D conversion means sets the predetermined number of times once for each half cycle of the power source.   The connection abnormality 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 predetermined connection abnormality determination level, The connection abnormality detection device according to any one of claims 13 to 16, wherein the connection abnormality is determined.   The connection abnormality 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 a predetermined connection abnormality determination level set in advance. The connection abnormality detection device according to claim 13, wherein when it is larger, it is determined that the connection is abnormal.   The connection abnormality determining means determines that a connection abnormality has occurred when the value of the digital value sampled by the A / D conversion means is smaller than a predetermined connection abnormality determination level set in advance. The connection abnormality detection device according to any one of 16.   The connection abnormality detection device according to any one of claims 17 to 19, wherein the connection abnormality determination unit sets a plurality of predetermined connection abnormality determination levels and determines the degree of abnormality of the connection portion in multiple stages. . A load electrically connected to the power supply via the connection,
A home electric appliance comprising the connection abnormality detection device according to claim 1.

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