JPH07274571A - Dc motor with rotary sensor - Google Patents

Abstract

PURPOSE:To simplify the whole device using a motor, and to improve maintainability at the time of the generation of trouble such as a failure by mounting a microcomputer discriminating and controlling the flow of overcurrent and a relay changing over the direction of rotation of the motor inside the motor body side when overcurrent flow by the abnormality of the motor. CONSTITUTION:When a window is fully closed and there is abnormality in the revolution of a motor, the positional memory of the window is rewritten in a microcomputer and a motor switch is turned off, and control in the microcomputer 4 is returned to first switch stand-by. When a human hand, etc., are held during the lifting of a window glass and abnormality is generated in the rotation of the motor, however, an exciting coil 3 is turned on by the microcomputer 4, and the motor is rotated reversely and the window glass is lowered. When the window glass is fully opened, the switch is turned off, the exciting coil 3 is turned off, and control in the microcomputer 4 is returned to first switch stand-by. Accordingly, a malfunction generated by disturbance is reduced, and maintenance is also facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a rotating state such as a current and a rotating position of a DC motor with a rotation sensor, diagnoses whether the motor is rotating normally, and detects abnormalities such as overload. Relates to a DC motor with a rotation sensor, which has means for reversing or stopping the motor to prevent the motor from being burnt out, the parts / devices to be used being damaged, or the human body being injured by the device using the motor.

[0002]

2. Description of the Related Art In recent years, the use of DC motors with a rotation sensor has been rapidly expanded. There are several methods for detecting abnormalities such as motor overload and restraint.

There is a method of stopping the energization of the motor when an overcurrent flows through the motor by using a circuit breaker or a current detection resistor, which can prevent the damage of the motor and parts or the danger to the human body. it can.

There is also a method in which a pulse wave signal from the rotation sensor is processed by a control circuit outside the motor, an abnormality in the rotation of the motor is detected, and the motor is rotated in the reverse direction.

[0005]

However, in the above-mentioned conventional configuration, since the circuit breaker has a large variation in characteristics, abnormalities such as overload, overcurrent or overheat cannot be accurately detected, and other than preventing burnout of the motor. It is difficult to use for the purpose. Further, in the abnormality determination method using the current detection resistor, since the rotation information is confirmed by the current, the error is large and the malfunction easily occurs.

In the method of processing the signal of the rotation sensor by the microcomputer to judge the rotation abnormality, the judgment accuracy is high and a complicated judgment reference can be provided. However, when the microcomputer circuit is installed outside the motor, not only the motor but also the entire device to which this motor is attached is investigated as a cause investigation when the device using this motor becomes defective. It is necessary to spend a lot of time for investigating the cause, and there is a problem that maintainability is difficult.

Next, problems with the conventional motor rotation abnormality detection method with a rotation sensor will be described. Conventionally, various methods for detecting the rotation speed of a motor with a rotation sensor include a method of converting a pulse signal from the rotation sensor into an analog value and a method of simply measuring a frequency using a microcomputer. However, in this method, when the motor decelerates for a short period of time due to a disturbance, an abnormality determination is likely to occur even if it is not an abnormal situation, resulting in a malfunction.

Further, when the motor driving power supply voltage changes or the characteristics and frictional resistance of the motor and the device driven by the motor change due to temperature, the rotation speed of the motor changes during normal operation. The microcomputer may mistakenly determine that the motor rotation is abnormal.

Further, in some cases, depending on the position of the motor rotor or the mechanical portion driven by the motor, reverse rotation may not be necessary even when the motor rotation is abnormal. However, in many conventional motor rotation abnormality detection systems with a rotation sensor, a signal related to the position of a mechanical portion driven by a rotor or a motor is not incorporated as a determination element for motor rotation abnormality determination. Alternatively, the position of the machine part driven by the rotor or motor by elements such as limit switches and sensors may be incorporated as a judgment factor for motor rotation abnormality judgment, but the number of elements and the number of wires must increase accordingly. It is disadvantageous in terms of maintenance and reliability.

[0010]

In order to achieve this object, a DC motor with a rotation sensor according to the present invention comprises a control circuit including a microcomputer for determining whether or not there is an abnormality in a pulse signal generated by the rotation sensor, and the control described above. A relay that operates by a signal from the circuit is used, and further, the control circuit is installed directly on the relay, and the relay is installed adjacent to the connector terminal of the power supply lead wire of the motor.

Further, a microcomputer is used as a method for detecting the abnormal rotation of the motor, and the following judgment is made in the microcomputer. First, the number of pulses from the motor rotation sensor is detected each time within a preset time or within a certain time calculated by a microcomputer, and the cumulative or continuous number of times when the number of pulses falls below a certain set value It is judged that the motor rotation is abnormal when the number of times exceeds a certain set number. Then, the motor reverse operation processing is performed in accordance with the instruction from the microcomputer. A DC motor with a rotation sensor having such a function is provided. In addition, the above-mentioned pulse number measurement time width, pulse number setting value for judgment, and the number of setting times are set as the constants of the microcomputer program in advance, or the information from the sensor that reads the motor surrounding environment or the information of the motor drive power supply. It is a constant or variable value when it is calculated by the microcomputer at any time based on the above, or is determined by the variable resistance of the microcomputer peripheral circuit.

Further, by processing the rotation sensor signal inside the microcomputer, the position of the mechanical part driven by the rotor or the motor is stored inside the microcomputer, and when the position is at the set position. It is also possible to provide a motor that reversely rotates the motor only when a motor abnormality is detected.

[0013]

With this configuration, when the DC motor with the rotation sensor falls into an abnormal state such as overload, overcurrent, or overheat,
These abnormalities can be detected on the motor side and corrective actions such as reversing the motor can be performed, and not only protection of damage to the motor itself but also damage to parts used in the motor and use of this motor It is possible to prevent damage to existing equipment, and also to prevent injury to the human body caused by this equipment. In particular, the abnormality determination by the microcomputer has few malfunctions caused by the disturbance, and installing the microcomputer on the motor body side facilitates maintenance.

Further, by adopting the motor abnormality determination method of the present invention, malfunctions are further reduced, and the set value used for the determination can be set according to the characteristics of the device using the motor, or various sensors can be controlled by a microcomputer. The motor of the present invention can be used in various usage environments by incorporating it into

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram of a DC motor with a rotation sensor according to an embodiment of the present invention, FIG. 3 is a flow chart executed inside the microcomputer of FIG. 1, and FIG. 4 is a motor abnormality determination method inside the microcomputer. It is a principle diagram.

In this embodiment, the case where the motor of the present invention is used in a power window system for an automobile will be described.
It goes without saying that it is not limited to the power window system for automobiles.

First, the configuration will be briefly described with reference to FIG.
The relay section 1 is composed of contacts a, b, c and d, an exciting coil 3 and a microcomputer circuit 4a. Reference numeral 2 denotes a motor switch, which is automatically turned off when an overcurrent occurs in this example. The exciting coil 3 is connected to the microcomputer 4 through a motor reverse signal line 24. When the microcomputer 4 determines that the motor is abnormal, it outputs a signal to the reverse rotation signal line 24 to activate the exciting coil. The connector portion 7 provided with terminals is for connecting to the motor switch 2 provided outside the motor and the microcomputer 4. Reference numeral 5 denotes a slip ring sensor which is an example of a rotation sensor, and this sensor pulse signal is sent to the microcomputer 4 through the sensor pulse signal line 21. 6 is a brush, 9 is an armature (rotor), 10 is a speed reducer (worm gear) mechanically coupled to the armature 9,
Reference numeral 8 is a temperature sensor.

FIG. 2A shows an example of an automobile power window system using the DC motor with a rotation sensor of the present invention. 12 is a circuit breaker, 14 is a window glass, 16 is a guide, 15 is a door, 13 is a regulator,
Reference numeral 2 is a motor switch, and 31 is a DC motor with a rotation sensor.

FIG. 2B is an external view of the DC motor 31 with a rotation sensor according to the present invention. FIG. 3 and FIG. 4 show an example of a thinking routine implemented in the microcomputer 4 according to one embodiment of claims 2 and 3. FIG. 3 is a flowchart block diagram, and FIG. 4 is a principle diagram of a motor rotation abnormality determination method.

Referring to FIG. In the 40th part, the microcomputer is initialized, but at the same time, the value of the initial position of the window is entered. Normally, the part 41 is on standby until the motor switch 2 is turned on. In the 43 part, when the state of the motor switch 2 is changed during the motor operation, the 45 part finds the current position of the window glass 14 and stores the position and returns to the 41 part. As will be described with reference to FIG. 4 in the portion 44, it is determined whether or not the motor rotation state is abnormal. In addition,
The fixed time, the set value, and the set number of times are 42 in this example.
A variable value is calculated and finely adjusted based on the information from the motor ambient temperature sensor 8 by a part. In the 46th part, in the present example, the window glass 14 is rising, and the motor reversing excitation coil 3 is turned on only when the motor rotation abnormality is detected when the window glass 14 is not in the fully closed state. . When an abnormality is detected while the window glass 14 is descending or when the window glass 14 is fully closed, in this example, the motor switch automatically returns due to the motor overcurrent and returns to the portion 41.

Next, the principle of the motor rotation abnormality determination method of FIG. 4 will be described. In the figure, 50 is a time zone set for sensor pulse measurement, and the number of motor sensor pulse waves 51 in this time zone is counted like 52. If the set number of pulses is 2, the cumulative number indicated by 53 is incremented by 1 when the number of pulses 52 is 2 or less. Here, if the set cumulative number is 5, the microcomputer determines that the motor is in an abnormal state when the cumulative number in 53 becomes 5 or more. In this way, the motor rotation abnormality determination is performed. There is also a determination method in which the number 53 in the drawing is set to the continuous number instead of the cumulative number, and the determination method that is adapted to the characteristics of the motor device may be adopted. In this figure, the pulse measurement installation time zone 50, the set number of pulses for determination, and the set number of times are constant, but if they are variable, more accurate determination can be realized.

The above is the description of FIGS. 3 and 4, but an actual operation example will be described with reference to FIG. First, the motor switch 2
Switch on the power window rise at. The state of the switch is determined by the window rising signal line 22,
It is sent to the input terminal of the microcomputer 4 through the window descending signal line 23. The exciting coil 3 is in the OFF state, and the motor rotation starts so that the window glass 14 rises. At the same time, the microcomputer 4 processes the pulse signal from the slip ring sensor 5 to start the determination of motor rotation abnormality. If the window is fully closed after that and the rotation of the motor becomes abnormal, the position memory of the window is rewritten in the microcomputer, the motor switch 2 is turned off, and the control inside the microcomputer returns to the first switch waiting. However, when an abnormality occurs in the rotation of the motor due to a human hand or the like being caught while the window glass 14 is rising, the microcomputer turns on the exciting coil 3, the motor reverses, and the window glass 14 descends. Then, the window glass 14
When is fully opened, the switch is turned off, the exciting coil 3 is turned off, and the control inside the microcomputer returns to the first switch waiting.

The above is the embodiment and description using the motor of the present invention. In this embodiment, the signal of the temperature sensor 8 is processed to change the sensitivity of the motor rotation abnormality determination, but such a signal, for example, the power source (battery) 1 is used.
At least one signal such as a signal related to the voltage or current of 1, a motor internal or external temperature signal, a motor peripheral temperature or a temperature signal of a motor peripheral device is sent to the microcomputer, and the signal is processed by the microcomputer to detect the motor abnormality determination sensitivity. By adding the function of adjustment, it is possible to realize a more advanced system that is less likely to malfunction due to temperature changes and voltage changes.

[0025]

As described above, according to the present invention, when an overcurrent flows due to a motor abnormality, the microcomputer for discriminating and controlling the overcurrent and the relay for switching the rotation direction of the motor are provided not on the outside of the motor but on the motor body side. By providing it inside, the whole device using the motor is simplified, which is also advantageous in terms of maintainability when a failure such as a failure occurs. Further, even when the present function is to be added to a device that does not have the function of the related art, that is, a device that does not have the function of performing self-correction operation such as reverse rotation when the motor is abnormal, No need to replace the motor or add a relay unit equipped with a microcomputer to the conventional motor lead wire, which can suppress new investment and is advantageous in terms of price.

Further, as the motor rotation abnormality determination factor, the motor rotation abnormality is determined not by the number of sensor pulses in a certain period of time but by the number of times when the number of sensor pulses in a certain time zone is equal to or less than a set value. Even when the motor rotation is temporarily reduced due to time disturbance and immediately returns to normal, malfunction reverse is rare.
In addition, since the setting items are the measurement time zone, the number of judgment pulses, and the number of judgments (cumulative number, continuous number), emphasis is placed on which of the above settings depending on the mechanical characteristics of the device using the motor, the purpose of using the device, etc. You can choose whether to put it or not, and you can realize highly precise control.

Further, by making the setting time zone of sensor pulse measurement, the number of setting pulses for microcomputer determination, and the number of setting times for determination variable, it is possible to make an optimum abnormality determination for the device and environment in use. When the preset time zone, preset pulse number, and preset number are stored in advance in the microcomputer memory as data by an operation experiment, or when the microcomputer sets at any time by calculation from the information of various sensor elements provided in the motor or the motor device. When the position of the motor rotor or the motor connecting device is changed, the application of this system is widened, and highly accurate abnormality determination is possible.

When the position of the motor rotor is calculated from the number of rotation sensor pulses and stored in the microcomputer,
It becomes possible to perform the reverse rotation process when the motor is abnormal with the condition of the position, and the conventional limit switch and position sensor are not required.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a DC motor with a rotation sensor according to an embodiment of the present invention.

FIG. 2A is a schematic external view of a power window motor system for an automobile equipped with a motor according to an embodiment of the present invention. FIG. 2B is a schematic external view of a DC motor with a rotation sensor according to an embodiment of the present invention.

FIG. 3 is a flowchart of a microcomputer installed in a DC motor with a rotation sensor according to an embodiment of the present invention.

FIG. 4 is a diagram showing the principle of a conventional motor abnormality determination method adopted in a microcomputer.

[Explanation of symbols]

1 relay part 2 motor switch 3 exciting coil 4 microcomputer 4a microcomputer circuit 5 slip ring sensor 6 brush 7 connector part 8 temperature sensor 9 armature (rotor) 10 speed reducer (worm gear) 11 power supply (battery) 12 circuit breaker 13 regulator 14 Window glass 15 Door 16 Guide 21 Sensor pulse signal line 22 Window up signal line 23 Window down signal line 31 DC motor with rotation sensor 40, 41, 42, 43, 44, 45, 46 Each part of microcomputer internal control flow chart 50 Pulse measurement setting Time zone 51 Rotation sensor pulse waveform 52 Number of pulses in the set time zone 53 Cumulative number of sections below the set number of pulses

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Claims (4)

[Claims] 1. A DC motor with a rotation sensor, comprising a worm gear formed at the tip of a motor shaft and a worm wheel arranged so as to be oriented in a direction of a rotation center axis perpendicular to the shaft, the rotation sensor detecting a rotation state of the motor. And a control circuit including a microcomputer for determining whether or not there is an abnormality in the pulse signal generated by the rotation sensor, and a relay operated by a signal from the control circuit, the control circuit being a connector terminal of a power supply lead wire. And a motor stator, and the control circuit is arranged adjacent to a connector terminal of a lead wire for power supply of the DC motor. 2. A rotation sensor and a control circuit including a microcomputer for processing a pulse signal generated by the rotation sensor, wherein the rotation abnormality determination method for a motor is variable within the microcomputer during a set time. Detects the number of times when the number of pulses from the motor rotation sensor is below a certain set value, and when the cumulative number of detection times exceeds a certain set value, or the number of consecutively counted times is the set value A DC motor with a rotation sensor equipped with the control circuit, which determines that the motor is in an abnormal rotation when the above conditions occur and performs an abnormality processing operation. 3. A motor main body or a signal of a sensor attached to the periphery thereof, a peripheral device driven by the motor, a signal of a sensor attached to the periphery of the device, a signal regarding a motor drive power supply voltage, a motor operating current. The sensitivity of motor rotation abnormality detection is changed by processing at least one of the signals related to the value inside the microcomputer, and finely adjusting the set time, set value and number of times for abnormality determination based on this result. The DC motor with a rotation sensor according to claim 2, wherein 4. A position of a rotor of a motor or a mechanical portion driven by the motor is detected by processing a signal of a rotation sensor inside the microcomputer, and a position of the mechanical portion driven by the rotor of the motor or the motor is detected. When is in a certain position,
3. A microcomputer is used to execute the action when the motor rotation abnormality is determined.
DC motor with rotation sensor described.