JP2007195328A - Motor burning protecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable the drive of a motor to be resumed as quickly as possible after a stop for a motor burning protection, and to reduce manufacturing cost. <P>SOLUTION: This device is provided with an operation time detection portion 12 that detects an operation time by inputting an operation signal and a number-of-times-of-operations counter 13 that counts the number of times of the operations. The device is also provided with an upper limit value setting portion 15 that sets an upper limit value just prior to motor burning based on the operation time and the number of times of the operations, and a burning protection control portion 14 that calculates an overheat judgment value from the time and the number of times and outputs a signal to stop the motor if the overheat judgment value reaches the upper limit value. The motor burning protection control can be performed without providing particular parts like a thermistor or a current sensor, so that a cost-effective motor burning protecting device can be provided and the drive can be resumed without waiting for a reset unlike the thermistor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a motor burnout protection device for protecting burnout of a motor that is driven and controlled in accordance with an operation signal.

  Conventionally, in the case of using a motor as a drive source of various drive devices mounted on an automobile or the like, if the motor is locked due to an external factor, the motor will overheat and burn out. Therefore, some kind of motor burnout prevention means is provided. For example, a thermistor is provided to detect the temperature when the motor is overheated, and when the temperature exceeds a predetermined level, the power supply to the motor is cut off.

Further, in the case of detecting the temperature using the thermistor, the number of parts increases and the manufacturing cost also rises. Therefore, as a means for solving the problem, the operating current value and the operating time of the motor are detected and both detected values are detected. The amount of heat generated from the motor is calculated from the motor, and when the calculated value exceeds a specified value, the operation of the motor is prohibited (see, for example, Patent Document 1).
JP 2005-27452 A

  In the case of using the thermistor, it is possible to prevent further energization after overheating by the operation of the thermistor, but if the thermistor is still hot even after the cause is removed, the drive can be resumed immediately. There is a problem that you can not. Moreover, in the thing of patent document 1, since the operating current value divided into the case within the predetermined time calculates the sum total of the emitted-heat amount based on the total time when the operating current value was detected, Since the operating time and the operating current value are detected and calculated, there is a problem that the cost is increased by the current detector and the program is complicated.

  In order to solve such a problem and realize a simple motor burnout protection device capable of resuming driving as soon as possible and reducing the manufacturing cost, in the present invention, drive control is performed according to an operation signal. A motor burnout protection device for protecting the burnout of the motor to be operated, an operation time detecting means for detecting a continuous output time of the operation signal, and an operation number counter for counting the number of times the operation signal is output; An upper limit value setting unit that sets an upper limit value in a state where the motor is overheated to a predetermined temperature or more based on the output time and the number of times, and calculates an overheat determination value based on the output time and the number of times, and the overheat Burnout protection control means for outputting a signal for stopping the motor when the judgment value reaches the upper limit value is provided.

  In particular, the output time is divided into a plurality of time ranges, the allowable number of times is set for each time range corresponding to the upper limit value, and a signal for stopping the drive control of the motor by the burnout protection control means is provided. The output is preferably performed when the number of times reaches the allowable number for each time range, and counting by the operation number counter is preferably performed for each time range. Further, the motor is used as a drive source of the opening / closing body driving device, the opening / closing body driving device has a pinching detection means, and the pinching detection by the pinching detection means controls the drive control of the motor by the burnout protection control means. Priority should be given to the output of the signal to be stopped.

  As described above, according to the present invention, for example, by using the CPU, the operation signal output time (hereinafter referred to as operation time unless otherwise specified) and the number of operations are detected without using a special detector. These values are used to calculate an overheat determination value that is a parameter of the motor overheat state, and an upper limit value in a state where the motor is overheated to a predetermined temperature is set based on the operation time and the number of operations. Thus, both can be compared and the overheated state of the motor can be monitored. When it is determined that the overheat determination value has reached the upper limit value, separate components such as a thermistor and a current sensor are provided by stopping the driving of the motor in order to prevent burning due to further overheating. Therefore, it is possible to provide an inexpensive motor burnout protection device, and it is not necessary to wait for a return unlike a thermistor, so that the drive can be restarted promptly.

  In particular, by dividing the operation time into a plurality of times and setting the allowable number of operations corresponding to each as an upper limit value, the upper limit value can be set using a simple data table, and control can be easily performed. In addition, by counting the number of operations for each time range, an appropriate number can be set for each time range, and the control can be highly accurate. Further, by giving priority to pinching detection, a quick response at the time of pinching is ensured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram showing a power window device in an automobile to which the present invention is applied. Note that the present invention is applicable to any motor drive device, and is not limited to a power window device.

  As shown in the figure, the control unit 1 receives the open / close operation signals of the manual operation switch 2a and the automatic operation switch 2b provided in the driver's seat or the like, and the control unit 1 controls the motor 3 according to the operation signals. Forward / reverse drive control is performed. A window 4 is connected to the motor 3 by a link mechanism (not shown), the window 4 is opened and closed by forward and reverse rotation of the motor 3, and a rotation sensor 5 for detecting the rotation of the motor 3 is provided. A pulse signal is input to the control unit 1 to detect the behavior of the window 4.

  The control unit 1 includes an open / close control circuit 6 that outputs an automatic or manual open / close control signal according to each open / close operation signal from each switch 2a and 2b, and forward / reverse drive control of the motor 3 according to the open / close control signal. Drive circuit 7, an angular velocity calculation circuit 8 that calculates an angular velocity signal by inputting a rotation pulse signal, and a determination circuit that performs pinching determination by inputting an angular velocity signal and outputs a pinching determination signal to the opening / closing control circuit 6 and the drive circuit 7. 9 are provided. The open / close control circuit 6 outputs an open / close control signal only during operation when the open / close signal of the manual operation switch 2a is input, and continuously when the open / close signal of the automatic operation switch 2b is input. The open / close control signal is output.

  FIG. 2 shows a circuit block diagram of the switching control circuit 6 constructed according to the present invention. As shown in FIG. 2, each opening / closing operation signal from each switch 2a, 2b is input to the opening / closing control unit 11, and a control signal is output from the opening / closing control unit 11 to the drive circuit 7 accordingly. Yes. An operation time detection unit 12 as an operation time detection unit, an operation number counter 13, a burnout protection control unit 14 as a burnout protection control unit, and an upper limit setting unit 15 are provided.

  The operation time detection unit 12 detects one operation time (time when the switch is turned on) of each opening / closing operation signal and outputs the operation time to the burnout protection control unit 14. The operation number counter 13 counts the number of times of operation (number of times of change from off to on) according to the input of each open / close operation signal, and outputs the count value to the burnout protection control unit 14. The upper limit value setting unit 15 stores in advance a set upper limit value based on the integration of energization time as a guide for protecting the motor 3 from burning. Specifically, as shown in the data table of FIG. 3, the operation time (energization time) is divided into four. For example, when an operation from fully closed to fully open takes 3 seconds in the normal state, 3 If the second is the maximum value, the upper limit of the number of operations within 1 second is N1, the upper limit of the number of operations within 1 second is over N2, and the maximum number of operations within 2 seconds is over 3 seconds. The upper limit value is set as N3, and the upper limit value of the number of operations when the time exceeds 3 seconds is set as N4.

  For each of the upper limit values N1 to N4, the temperature rise value in each operation time of the motor 3 is measured by a test, and the allowable number of times until the temperature reaches a temperature before the limit value of the temperature at which the motor 3 is overheated. And In addition, as a setting before a limit value, it is good to set to about 80 to 90% with respect to a limit value. In addition, the time between the operations (resting time) may be arbitrary, but a time that is an interval for executing the repetitive operation considered in the normal use state is set. In addition, when it is necessary to consider the environment (temperature, voltage, etc.), it is preferable to set based on data suitable for the environment in which the apparatus is used.

  The burnout protection control unit 14 determines whether or not the input operation time and the number of operations are equal to or greater than the set value of the corresponding upper limit setting unit 15. In order to prevent further energization of 3, a drive stop signal is output to the drive circuit 7.

  Next, the control point of the stop process in the burnout protection control unit 14 will be described below with reference to the flowcharts of FIGS. In step ST1, it is determined whether or not each of the switches 2a and 2b has been operated. If it is determined that the switch has been operated, the process proceeds to determining whether or not the operation is prohibited in step ST2. Here, the operation stop state is a state where a motor stop process is performed by the burnout protection control unit 14.

  In step ST2, it is determined whether or not the operation is prohibited. If it is determined that the operation is not prohibited, the timer is reset in step ST3 and then the process proceeds to step 4 where it is determined that the operation is prohibited. Returns to step ST1. In step ST4, it is determined whether or not the stop is after the closing operation. If it is determined that the stop is not after the closing operation, the process proceeds to step ST5. In step ST5, it is determined whether or not the stop is after the opening operation. If it is determined that the stop is not after the opening operation, the process proceeds to step ST6. In step ST6, it is determined whether the motor is locked during the closing operation (UP operation) or the opening operation (DOWN operation). The determination of the locked state may be, for example, a case where it is detected that the window 4 has stopped at the fully open position or the fully closed position. If it is determined in step ST6 that a lock state has been detected, the process proceeds to step ST6a, where 1 is added to the lock count value (Cl) (Cl = Cl + 1), and the process proceeds to step ST7. If it is determined in step ST6 that the lock state is not established, the process proceeds to step ST7. In step ST7, it is determined whether or not the counting process after the stop is completed. If it is determined that the counting process is completed, the timer starts operating in step ST8 and then proceeds to step ST9 to complete the counting process. If it is determined that it is not, the process returns to step ST4. Here, completion of the count process means that the process of adding the count value by the operation number counter 13 is performed.

  In step ST9, it is determined whether or not the count value has reached the corresponding upper limit values N1 to N4. If it is determined that the upper limit has not been reached, the process returns to step ST1, and if it is determined that the upper limit has been reached, the process proceeds to step ST9a. In step ST9a, assuming that the motor 3 is energized until it is overheated, a process for stopping further operation of the motor 3 is performed. Specifically, the burnout protection control unit 14 outputs a drive prohibition signal to the drive circuit 7. When the drive prohibition signal is input to the drive circuit 7, the burnout protection control unit 14 inputs the open / close drive signal from the open / close control unit 11. Processing for prohibiting the operation by the motor 3 is performed with priority.

  Next, the outline of the counting process will be described. When it is determined in step ST1 that the switches 2a and 2b are not operated, that is, in the operation stop state, the process proceeds to step ST10, where it is determined whether or not the first specified time Ta has elapsed. Here, the first specified time Ta is the time of the timer started to operate in step ST8, and is the time when the temperature of the motor 3 may be lowered to the same level as the resting state. This may be regarded as an initial state, and when it is determined that such a first specified time Ta has elapsed, the process proceeds to step ST11 where all count values are cleared (= 0). Then, the process returns to step ST1.

  If it is determined in step ST10 that the first specified time Ta has not elapsed, it is determined in step ST12 whether the second specified time Tb (<Ta) has elapsed. Here, the second specified time Tb is a time that does not reach the initial state but may be cooled to some extent. Specifically, it is the time when the cooling time corresponding to one count value has elapsed. Therefore, if it is determined in step ST12 that the second specified time Tb has elapsed, the process proceeds to step ST13, where the count value is subtracted once. After step ST13, the process proceeds to step ST14, where it is determined whether or not the operation is prohibited. If the operation is prohibited, the process proceeds to step ST15 to release the operation prohibited state and returns to step ST1. If it is determined in step ST14 that the operation is not prohibited, the process returns to step 1 as it is.

  If it is determined in step ST4 that the stop is after the closing operation, the process proceeds to step ST16a. The measurement of the operation time is started from step ST2, and the continuous time (operation time) from the end of the operation (switch off) is measured and temporarily recorded in the memory. The transition from step ST4 to step ST16a is an operation stop condition, for example, when the period of the pulse wave from the rotation sensor 5 is equal to or greater than a predetermined value.

  In step ST16a, it is determined whether or not the closing operation time (M-UP) by the manual operation switch 2a is within 1 second. If it is determined that the operation has been continued for 1 second or longer, the process proceeds to step ST16b. If it is determined that the operation is within seconds, the process proceeds to step ST17a. In step ST17a, a process of adding 1 to the count value (Cmu1) as the overheat determination value corresponding to the manual closing operation time within 1 second is performed (Cmu1 = Cmu1 + 1), and the process proceeds to step ST5.

  Further, as described above, the operation time is divided into four, and in steps ST16b to 16d, the case where the target operation time is sequentially increased within 2 seconds, within 3 seconds, and over 3 seconds, respectively, is the same as in step ST16a. And the addition process in each step ST17b to 17d corresponding to each step ST16b to 16d is performed, and the description thereof is omitted. Each count value (Cmu2, Cmu3, Cmu4) for such a case division becomes an overheat determination value in each case (hereinafter the same in the same processing).

  Next, when it is determined in step ST16d that the operation time is not 3 seconds or more, the process proceeds to step ST18a. The case where the process proceeds to step ST18a is, for example, a case where the manual operation switch 2a is not closed, and each determination is performed in each step ST18a-18d for the automatic opening operation by the automatic operation switch 2b under the same time division condition as described above. Each of these steps ST18a to 18d corresponds to each of the above steps ST16a to 16d, and each of the steps ST19a to 19d that proceed when it is determined that the automatic opening operation time (A-UP) corresponds to each of the above steps ST19a to 19d. Corresponding to ST17a to 17d (each count value is Cau1, Cau2, Cau3, and Cau4), their description is omitted.

  If it is determined in step ST18d that the auto operation time is not 3 seconds or longer, the process proceeds to step ST20. As a case of proceeding to step ST20, an inversion operation due to pinching or the like can be considered. Therefore, in step ST20, it is determined whether or not pinching has been detected. The determination of the pinching may be, for example, a case where it is detected that the window 4 has stopped outside a predetermined range from the front of the fully closed position to the fully closed position. If it is determined in step ST20 that pinching has been detected, the process proceeds to step ST21, where 1 is added to the pinching inversion count value (Cc) (Cc = Cc + 1), and the process proceeds to step ST22. If it is not determined that pinching has been detected, the process proceeds to step ST22.

  As a case where the process proceeds to step ST22, there is a case where the process of the flow is not normally performed. For example, the count process is performed by steps ST16a to 16d and steps ST18a to 18d even though the motor operation command is input. This is the case when it was not missed. In step ST22, 1 is added to the post-stop count value Cs (Cs = Cs + 1), and the process proceeds to step ST5.

  In this way, processing is performed when the operation is stopped after the closing operation. Each count value is counted according to the length of the operation (operation) time as described above. In addition, in addition of each count value performed after the presence or absence of lock detection and pinching inversion, it may be a flag process for performing these processes.

  If it is determined in step ST5 that the operation has stopped after the opening operation, the process proceeds to step ST31a. In step ST31a, the same processing as step ST16a is performed with respect to the above-mentioned closing operation time (M-UP) only by the difference of the opening operation time (M-DOWN), and step ST32a that performs the corresponding count processing is also the same processing as step ST17a. The subsequent processing is the same. That is, steps ST31a to 31d correspond to steps ST16a to 16d, and steps ST32a to 32d correspond to steps ST17a to 17d. Similarly, also in the processing from step ST33a, steps ST33a to 33d are the same as steps ST18a to 18d, except for the automatic opening operation time (A-DOWN) with respect to the automatic closing operation time (A-UP). Since ST34a to 34d are the same as the above-described steps ST19a to 19d, the description thereof is omitted.

  If it is determined in step ST33d that the auto operation time is not 3 seconds or more, the process proceeds to step ST35. This step ST35 is the same as step ST22.

  The count values of steps ST32a to 32d are Cmd1 to Cmd4, the count values of steps ST34a to 34d are Cad1 to Cad4, the count value of step ST35 is Cs, and the respective steps are executed. Accordingly, the corresponding count value is incremented by one. And after performing the lock determination of step ST6, it progresses to step ST7.

  In step ST7, it is determined whether or not the count processing after the stop is completed as described above. The counts to be targeted are the count values Cmu1 to Cmu4 · Cau1 to Cau4 · Cmd1 to Cmd4 · Cad1 to Cad4 ·. Cs · Cc, and it is determined whether any one of them has been added. If any one of the count values has been added, the timer is operated in step ST8 and then the process proceeds to step ST9, where the count values Cmu1 to Cmu4, Cau1 to Cau4, Cmd1 to Cmd4, Cad1 to Cad4 are set. In this case, it is determined whether or not the corresponding upper limit values N1 to N4 have been reached.

  When the upper limit values N1 to N4 have been reached, and the count values Cs and Cc, the upper limit value may be 1, for example, and if any of these count values is 1, Proceeding to step ST9a, the operation prohibition is set there. An operation prohibition signal based on the setting is output from the burnout protection control unit 14 to the drive circuit 7, and the motor 3 stops.

  As a result, the motor 3 is stopped during the opening / closing operation for some reason, and the motor 3 is continuously energized when the operator is not aware of it or determines that the movement is slow and keeps the operation switch on many times. Therefore, it is possible to prevent overheating and reaching the burning temperature. At the time of locking such as freezing or pinching, the upper limit value is set to once as described above, so that stop processing is performed with priority over the case of operation time (N1 to N4> 1), Accurate processing according to the situation can be performed.

  In particular, by changing the upper limit value of the number of times of operation according to the length of the energization time in one switch operation, the motor 3 is cooled due to the off state before the next on operation, and therefore enters the operation prohibited state. Even in such a case, it is preferable to make a setting in consideration of the cooling state. In the illustrated example, the count value may be reset when a pause time that can be regarded as having been cooled to the initial temperature is reached by the processing in steps ST10 to ST15. Therefore, all count values are set in step ST11. Processing to clear.

  For example, when the temperature is increased by a single operation and is paused for a time during which the temperature can be cooled (off state), each count value is subtracted by 1, thereby resuming the operation after a certain pause. Such control can be performed in consideration of the operation. Thereby, quick return (operation possible state) is possible, and it is possible to avoid a non-energized state until the return of the element as in the case of using a thermistor or a circuit breaker.

  In this way, it is possible to prevent burning due to overheating of the motor 3 without detecting the overheating state of the motor 3 with a thermistor or incorporating a circuit breaker circuit. A burnout protection device can be realized. Further, the case classification of operation time and the setting of the upper limit value can be freely written in the ROM, an appropriate value can be set for each device, and versatility is high. Moreover, all can be performed by program control, and it can respond flexibly to a design change.

  In the above illustrated example, the case where the operation time is divided into four ranges and counted for each example is shown as an example, and is not limited. For example, the operation time may be multiplied by the number of operations, or weighted according to the length of the operation time, multiplied by the number of operations as a coefficient, and determined using the sum of the multiplication values. good. Further, in the present embodiment, the case where the counter subtraction and reset are measured by the timer only in the nearest operation is shown, but the present invention is not limited to this. For example, the first specified time is set for all inputs of the switches 2a and 2b. You may measure whether Ta passed.

It is a schematic block diagram of the power window apparatus in the motor vehicle to which this invention was applied. It is a schematic block circuit diagram of a control circuit. It is a figure which shows the data table of an upper limit. It is a figure which shows a part of control flow. It is a figure which shows the part following FIG. 4 of a control flow. It is a figure which shows the part following FIG. 5 of a control flow.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control part 2a Manual operation switch, 2b Auto operation switch 3 Motor 4 Window 5 Rotation sensor 6 Opening / closing control circuit 7 Drive circuit 11 Opening / closing control part 12 Operation time detection part 13 Operation frequency counter 14 Burnout protection control part 15 Upper limit setting part

Claims (4)

A motor burnout protection device for protecting burnout of a motor driven and controlled in accordance with an operation signal,
An operation time detecting means for detecting a continuous output time of the operation signal, an operation number counter for counting the number of times the operation signal is output, and an upper limit value in a state where the motor is overheated to a predetermined temperature or more. And an upper limit setting unit set on the basis of the number of times, an overheat determination value based on the output time and the number of times, and a signal for stopping the motor when the overheat determination value reaches the upper limit value A motor burnout protection device comprising a burnout protection control means. The output time is divided into a plurality of time ranges, and the upper limit value is set according to the allowable number of times for the time ranges,
2. The motor burnout protection device according to claim 1, wherein a signal for stopping the drive control of the motor by the burnout protection control unit is output when the number of times reaches the permissible number for each time range. .   The motor burnout protection device according to claim 1 or 2, wherein counting by the operation number counter is performed for each time range. The motor is used as a drive source of the opening / closing body drive device,
The opening / closing body driving device has a pinching detection means,
4. The motor according to claim 1, wherein the pinching detection by the pinching detection unit is prioritized over the output of a signal for stopping the drive control of the motor by the burnout protection control unit. 5. Burnout protection device.

Images