JPH065263Y2 - Electric retractable mirror control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a door mirror, in which the rotation of the door mirror is stopped by the rotation restricting means at the standing position and the storage position, and the drive circuit of the motor is cut off. In addition, the present invention relates to a control device for an electric retractable mirror that can cope with a sudden unturnable accident.

[Prior Art] In an electric retractable mirror, as shown in FIGS. 4 to 5, a base plate 51 is fixedly mounted on an overhanging portion 50a from a base 50, and a frame 54 is rotated on a shaft 52 standing on the base plate 51. The mirror body 53 fixed to the frame is erected or stored by rotating the frame 54 by driving the motor. The thing which stops rotation by a motion control means is used.

The rotation restricting means includes a rotation restricting means provided at the standing position and a rotation restricting means provided at the storage position.

The former is composed of a ring-shaped stopper plate 60 fixedly mounted on the base plate 51 and a ball 61 fitted in a concave portion of the lower surface of the frame 54. The sawtooth-shaped projections provided on the stopper plate 60 serve as a stand-up position detection stopper. 62 is formed, and the ball 61 is brought into contact with the stopper 62 to stop the mirror body 53 at the standing position.

In the latter case, the convex portion 65 is provided outside the stopper plate 60 on the base plate 51, and the fitting groove 64 that fits in the convex portion 65 is provided on the lower surface of the frame 54. A detection stopper 63 is formed, and the convex portion 65 is brought into contact with the stopper to bring the mirror body 53 into the storage position.
Is to stop.

The rotation restricting means stops the rotation of the mirror body, detects the rapidly increasing load current of the motor, and automatically shuts off the drive circuit to stop the drive of the motor. That is, a control device of this type uses a method of controlling the drive of the motor by converting the load current of the motor into a voltage and comparing it with a reference voltage.

[Problems to be Solved by the Invention] In the conventional method of controlling the drive of the motor, the reference voltage, which is the detection level, is fixed, but the load current of the motor varies with changes in the outside temperature and variations during assembly. In many cases, the load current value increases or decreases due to variations in component tolerances, etc., causing malfunctions.

The present invention ensures that the rotation of the door mirror is stopped by the rotation restricting means and the driving of the motor is stopped at the upright position and the retracted position of the door mirror without causing a malfunction due to a temperature difference and a variation in parts assembly. An object is to provide a control device for controlling a door mirror.

[Means for Solving the Problems] In order to achieve the above object, the present invention converts a load current of a motor into a time-series digital value and controls the degree of fluctuation of the digital value by comparing with a reference value. I chose That is, by rotating the built-in motor forward and backward, the door mirror is rotated in the upright direction or the storage direction, the rotation restricting means in the upright position and the storage position stops the rotation of the door mirror, and the detection circuit detects the motor. In a control device for detecting a load current for each of the left and right mirrors and stopping driving of a motor; a motor load current detection circuit; an A / D conversion unit for converting the detected analog value into a finite number of discrete digital signals; An arithmetic unit that outputs a control signal by comparing the degree of increase of the time-series digital value output from the circuit with a reference value, a motor drive circuit that operates according to the control signal, and a motor. is there.

The arithmetic unit is provided with a time zone for preventing erroneous detection at the time of starting the motor, and is operated after the lapse of the time zone. Further, the arithmetic unit may be provided with an operation time period including a predetermined drive time of the motor, and after the time period has passed, the drive of the motor may be stopped.

[Operation] Since the present invention is configured as described above, after the motor is driven, and after the erroneous detection prevention time due to the inrush current at the time of start-up has elapsed, the calculation unit starts operating and the predetermined drive time of the motor is maintained. During a specific operating time period including, the A / D converter is instructed to sample and quantize the analog signal from the load current detection circuit.

A time-series digital signal is output from the A / D converter to the calculator in response to the command, and the calculator calculates the degree of increase of the input time-series digital signal and compares it with a reference value to obtain a reference value. When it becomes larger, it is considered that the motor is overloaded and a control signal for stopping the driving of the motor is output to the motor drive circuit. When the motor is still energized even after the operating time of the arithmetic unit has passed, it is considered that the motor cannot be rotated due to some abnormal situation, and the arithmetic unit stops the motor drive by the motor drive circuit. Output a control signal. The motor drive circuit stops driving the motor based on the control signal.

Thus, the door mirror stops rotating after the erroneous detection prevention time of the motor starting time has passed or is stopped by the circuit restricting means or other structure, or automatically stops the motor when an obstacle near rotation is received. Let

EXAMPLES Examples will be described below with reference to the drawings. FIG. 1 is a block diagram of a control device for a right side door mirror showing an outline of the present invention, and FIG. 2 is a flow chart diagram showing an operating state of a computing unit. In the figure, 10 is a one-push type operation switch for forward / reverse switching, 11 is a motor drive circuit, 15 is a load current detection circuit, motor R is a right side motor, 20 is an A / D converter, 21 is a sample and hold circuit, 22 is an A / D converter, 25 is an arithmetic unit, 26 is a CPU, and 27 is a memory.

The present invention comprises a one-push type operation switch 10 which is a forward / reverse direction switch, a motor drive circuit 11, a load current detection circuit 15, a motor R, an A / D conversion section 20, and a calculation section 25. Become.

The motor drive circuit 11 uses the control signal from the arithmetic unit 25 to drive the motor R
Drive or stop the load current detection circuit 15
The load current is converted into a voltage, and the analog output value is input to the A / D converter 20 described later. A / D
The conversion unit 20 is composed of a sample and hold circuit 21 and an A / D converter 22, and the analog output value is A / D converted by a command from the calculation unit 25 to be calculated by the A / D converter 22.
A digital signal is output to. That is, the sample and hold circuit 21 has an operational amplifier, a capacitor, and the like as main components, and samples the analog input signal that changes momentarily through a transistor or the like based on a sampling command from the arithmetic unit 25, and then performs the next sampling. Hold until commanded. The A / D converter 22 quantizes the signal sampled and held by the sample and hold circuit 21 and converts it into a discrete digital signal. For example, a successive-approximation type converter is activated for each command from the arithmetic unit and outputs a time-series digital signal.

The arithmetic unit 25 is composed of a CPU 26, a memory 27, etc., and operates according to the flow chart shown in FIG.
The motor drive circuit 11 calculates the digital input signal from
Output a control signal to. That is, the degree of change of the time-series digital input signal sampled and held and quantized is calculated, and the calculated value is compared with a reference value, and when the value is larger than the reference value, the driving of the motor is stopped. Therefore, a control signal is output to the drive circuit 11.

In the calculation of the calculation unit 25, an operation time period T for 16 seconds including a predetermined drive time of the motor is provided from the start of the motor drive, and the motor is started for 0.6 seconds corresponding to the start time of the motor from the start of the drive. Erroneous detection due to inrush current is set as an inactive dead zone as a time zone for prevention, and after the operating time zone T, the drive of the motor is forcibly stopped, resulting in an accident that the motor cannot be driven due to some cause. I can deal with it.

A differential amplifier circuit using an operational amplifier for input signal amplification and a low pass filter for nozzle removal may be provided between the load current detection circuit 15 and the sample and hold circuit 21. The operation can also be performed by the arithmetic unit 23.

Although not shown, the DPCM formula is used for the A / D converter of the conversion unit in FIG. 1 to calculate the difference between the previous measurement value and the current measurement value as an analog value, and then the difference is digitally converted. May be. Alternatively, a multiplexer may be provided in the A / D conversion unit in FIG. 1 to control the left and right door mirrors with a set of the calculation unit and the A / D conversion unit.

The operation of the present invention will be described below with reference to the flow chart shown in FIG.

Stage, and Up to this point, the operation process of raising or retracting the door mirror by the operation of the operation switch is shown. The motor starts left rotation or right rotation according to a command from the calculation unit, the door mirror starts to rotate, and the timer for setting the operation time zone (T) of the calculation unit starts to operate on the stage. After 0.6 seconds, which is the erroneous detection prevention time when the motor is started, elapses after the motor starts to be driven on the stage, the arithmetic unit shifts to the operating state.

In the stage, the arithmetic unit commands the sample and hold circuit 21 and the A / D converter 22 to sample and quantize the analog signal detected by the load current detection circuit 15 and converted into voltage.

Then, in the stage, the first time-series digital signal (NO.1) is output from the A / D converter 22 to the arithmetic unit, and in the stage, the signal (NO.1) is stored in the save data memory of the memory 27.

In the stage, when the lower limit of 16 seconds of the operating time period T has passed, a motor drive stop signal is output to the motor drive circuit 11 in the stage.

If the operating time period T does not elapse on the stage, the stage shifts to the stage and below. That is, on the stage
NO.2 standardized quantization command is sample and hold circuit 2
1. The signal is output to the A / D converter 22, and the digital signal (NO.2) is output from the A / D converter 22 to the arithmetic unit 25 in the stage, and the signal (NO.2) is output to the voltage data memory of the memory 27 in the stage. Remembered.

The signal NO.2 of the voltage data memory stored previously in the stage and the signal N stored in the save data memory
The difference from O.1 is calculated.

In the stage, the calculated voltage difference ΔV (signal N
O.2-Signal NO.1) is larger than the reference value n, that is,
When it is detected that an overload current has flown into the motor, a motor drive stop control signal is output to the motor drive circuit 11 in the stage.

In the stage, the signal NO.2 is transferred from the voltage data memory to the save data memory while the voltage difference is smaller than the reference value in the comparison operation in the stage, then returns to the stage, and 16 seconds after the motor drive is started. Repeat the process of stage ~ while not in progress.

The operation of the stage is continued in the operation time period T until No _{i + 1-} No _i at which the overload current is detected. In the stage, after the motor drive stop signal is output, the process returns to the stage, and the stopped state is continued unless the operation switch is turned on again.

FIG. 3 shows the relationship between the load current of the motor and the time t. As shown in the figure, the operating time zone of the arithmetic unit is T including the predetermined drive time of the motor, and the false detection prevention time due to the motor inrush current is shown. The band is a dead band that has not been operated. The overload current when the rotation of the mirror is stopped by the rotation restricting means in the standing position or the storage position in the time zone and the overload current when the rotation failure is caused by another structure are detected. Alternatively, if the mirror does not reach the upright position or the storage position for some reason even after the operation time period T has passed, the drive of the motor is forcibly stopped.

[Advantages of the Invention] Since the present invention is configured as described above, it has the following effects. That is, the analog value of the detected load current is sampled and quantized, and the time-series digital value is output to the arithmetic unit, and the arithmetic unit compares the degree of change of the time-series digital value with a reference value to drive the motor. Since it is stopped, there is no malfunction due to changes in outside temperature, variations in component accuracy, and variations during assembly, and the calculation unit has a time zone to prevent false detection during motor startup, so there is no rush during motor startup. It is possible to prevent erroneous detection due to electric current, and because the operating time zone including the predetermined drive time of the motor is set, it is possible to provide a safety function to forcibly stop the driving of the motor after the erroneous time zone has passed, and It is possible to provide an electric retractable mirror control device that operates reliably.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a control device for a right side door mirror showing an outline of the present invention, FIG. 2 is a flow chart diagram showing an operating state of a computing unit, and FIG. 3 is a time diagram of a motor load current. FIG. 4 is a view showing a change, FIG. 4 is a view showing a conventional rotation restricting means of a door mirror, and FIG. 5 is an exploded perspective view of the rotation restricting means. 10 ... Operation switch, 11 ... Motor drive circuit, 15 ... Load current detection circuit, 20 ... A / D converter, 21 ... Sample and hold circuit, 22 ... A / D converter, 25 ... Calculation Part, 26 …… CPU, 27 …… memory, 50 …… base, 51 ……
Base plate, 52 ... Shaft, 53 ... Mirror body, 54 ... Frame, 55 ... Socket part, 60 ... Stopper plate, 61 ... Ball, 62 ... Standing position detection stopper, 63 ... Storage position detection stopper , 64 …… Mating groove, 65…
… Convex part.

Claims (3)

[Scope of utility model registration request] 1. A door mirror is rotated in a standing direction or a storage direction by rotating a built-in motor forward and backward, and rotation of the door mirror is stopped by a rotation restricting means at the standing position and the storage position. In a control device for detecting a load current of a motor for each of the left and right mirrors to stop driving of the motor; a motor load current detection circuit and an A / D converter for converting a detected analog value into a finite number of discrete digital signals. And a calculation unit that outputs a control signal by comparing the degree of increase of the time-series output value output from the circuit with a reference value, a motor drive circuit that operates according to the control signal, and a motor. Electric retractable mirror control device. 2. The electric retractable mirror control device according to claim 1, wherein the arithmetic unit is provided with a time zone for preventing erroneous detection at the time of starting the motor, and is operated after the lapse of the time zone. 3. The electric retractable mirror according to claim 1, wherein the arithmetic unit provides an operating time period including a predetermined time drive time of the motor, and outputs a control signal for stopping the drive of the motor after the time period elapses. Control device.