JPS6159068B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a safety control device for an electric opening/closing device used, for example, in an automobile's power window or electric sunroof. When closing a power window or an electric sunroof of an automobile, it is desirable that the power window or electric sunroof of an automobile immediately stop if an obstacle such as a human body is caught between the opening/closing body made of the window glass or sunroof and the opening edge of the vehicle body. Conventionally, in such a case, a mechanism has been used to immediately stop the opening/closing body. However, conventional devices are equipped with a safety switch on the edge of the opening so that the safety switch is activated only when a human body or the like is pressed against the opening/closing body, or they measure the current flowing through the electric motor. The electric motor was stopped by detecting an increase in current when a human body was caught in the opening/closing body, so there were problems such as having to install a safety switch across the entire width of the opening edge, motor characteristics, opening/closing There was a problem in that it was affected by variations in the operating resistance of the body, changes in operating resistance during use, etc., and there was still room for improvement in terms of sensitivity and stability. This invention was made in view of these points, and it is based on the characteristic that the current flowing through the electric motor has a small change when the opening/closing body is operating normally, but increases rapidly when a human body etc. is pinched. This system detects a sudden change from the normal current and stops the electric motor. Next, an embodiment of the present invention will be described with reference to FIG. 1. Reference numeral 1 is a battery mounted on an automobile, the negative electrode of which is grounded to the vehicle body. The positive side of the battery 1 is connected to one movable contact of a two-pole, double-throw changeover switch 2. The other movable contact of the changeover switch 2 is connected to the terminal c of the safety control device 3 according to the present invention. An electric motor 4 is connected between two fixed contacts on one side of the changeover switch 2, which serves as a drive source for an opening/closing body such as a window glass or an electric sunroof. Two fixed contacts on the other side of the changeover switch 2 are connected to terminals a and b of the safety control device 3. Note that the two sets of fixed contacts are cross-connected, and the direction of rotation of the electric motor 4 is changed depending on the position of the movable contacts. In this example, when the movable contact is tilted to the left side of the figure, the opening/closing body opens.
It is designed to close when tilted to the right side. The safety control device 3 is provided with four terminals a, b, c, and d. Terminals a, b, and c are connected as described above, and terminal d is grounded to the vehicle body. Terminals a and b are connected to the input side of a constant voltage power supply circuit 7 via diodes 5 and 6. The output side of the constant voltage power supply circuit 7 is connected to one input terminal of a first comparison circuit 9 via a variable resistor 8. The other input terminal of the first comparator circuit 9 is connected to the output terminal of the filter/amplifier circuit 10. One input end of the filter/amplifier circuit 10 is connected to terminal c, and the other input end is grounded to the vehicle body. A shunt resistor 11 and a normally closed contact 12a of a relay 12 whose one end is connected to the output side of the constant voltage power supply circuit 7 are connected in series between the terminals c and d. The output terminal of the filter/amplifier circuit 10 is connected to one input terminal of the first comparison circuit 9 described above as well as one input terminal of a second comparison circuit 14 via a variable resistor 13. The other input terminal is also connected through a parallel circuit of a diode 15 and a resistor 16. Note that this input terminal is connected to capacitor 17.
The vehicle body is grounded through. The output terminal of the second comparison circuit 14 is connected to one input terminal of the first NAND circuit 18. The other input terminal of the first NAND circuit 18 is connected to a timer 1 whose one end is connected to the output side of the constant voltage power supply circuit 7.
The other end of 9 is connected. First NAND circuit 1
The output terminal of 8 is connected to one input terminal of the second NAND circuit 20. The output terminal of the first comparator circuit 9 is connected to one end of the display lamp 21 and the other input terminal of the second NAND circuit 20. The other end of the indicator lamp 21 is grounded to the vehicle body. The output terminal of the second NAND circuit 20 is connected to the base of the transistor 22. transistor 2
Reference numeral 2 controls the energization of the relay 12 described above, and this relay 12 is connected to the collector. The emitter of the transistor 22 is grounded to the vehicle body. A normally open contact 12b of the relay 12 is connected between the collector and emitter of the transistor 22. This safety control device configured in this manner operates as follows. First, when the movable contact of the changeover switch 2 is brought into contact with the fixed contact on the right side in order to close the opening/closing body, the current from the battery 1 is transferred to the upper movable contact, the fixed contact, the electric motor 4, the fixed contact, the lower movable contact, The current flows through the vehicle body grounding circuit from the shunt resistor 11 and the normally closed contact 12a of the relay 12, which is closed at this point, and the electric motor 4 rotates in the direction in which the opening/closing body closes. At this time, the current flowing through the electric motor 4 changes as shown by A in FIG. 2 during startup and during normal operation. The current flowing to the electric motor 4 also flows to the filter/amplifier circuit 10 from the terminal c. Here, this current is converted into a voltage, smoothed, amplified, and output as shown in FIG. 2B. The signal output from this filter/amplifier circuit 10 is converted to a signal shown by C in FIG. 2 via a variable resistor 13, and is input to a second comparison circuit 14.
The signal is converted into a signal shown by D in FIG. 2 through an integrating circuit consisting of a resistor 16 and a capacitor 17, and is input to the second comparison circuit 14. Note that the level of the signal C is set by the variable resistor 13 so that it has a lower level than the signal D that has passed through the integration circuit during normal operation. By adjusting the variable resistor 13 in this way, sensitivity to current changes can be set. The signal C and the signal D are compared in the second comparison circuit 14, and when the level of the signal C becomes higher than the level of the signal D, as shown in E in FIG. Output a signal. On the other hand, the current that enters the constant voltage power supply circuit 7 from the terminal a via the diode 5 is maintained at a constant voltage and enters the timer 19, which is activated.
This timer 19 is set to output a signal at a constant level only when an initial time t0 has elapsed after the changeover switch ₂ is connected, as shown by F in FIG. 2, and acts as a delay circuit. . The initial time t ₀ is set to be longer than the time it takes for the rising current to change to a stable current at the time of starting the electric motor 4 (about 0.3 seconds). Output signal from second comparison circuit 14 and timer 1
The output signal from 9 is input to a first NAND circuit 18 for calculation. Since this circuit is a NAND circuit, it will not output when the two input signals are input at the same time, and will not output when either one of the signals is input or when neither signal is input. It will output a signal at a constant level. Further, the current maintained at a constant voltage by the constant voltage power supply circuit 7 is input as a set reference voltage to the first comparator circuit 9 through the variable resistor 8, and the filter
It is compared with the output signal from the amplifier circuit 10, and if the output signal from the filter/amplifier circuit 10 is lower than the set reference voltage, a signal at a constant level is output and the indicator lamp 21 is turned on. Further, when the voltage becomes higher than the set reference voltage, the output is stopped and the indicator lamp 21 is turned off. The output signal from the first comparator circuit 9 and the output signal from the first NAND circuit 18 are input to a second NAND circuit 20 for calculation. This second NAND circuit also does not output when both signals are input at the same time, but outputs a constant level signal when either signal is input or when neither signal is input. The transistor 22 is turned on, and the relay 12 is energized. When relay 12 is energized and activated, normally closed contact 1
Since 2a opens, the current to the electric motor is cut off.
Electric motor 4 stops. This causes the opening/closing body to stop at that position. Note that when the relay 12 is activated, the normally open contact 12b closes and short-circuits the transistor 22, so that it is self-maintained in this state until the changeover switch 2 is turned off. Next, the operation will be explained in detail by dividing into startup, normal, abnormal, and fully closed states. (1) At startup At the moment when the changeover switch 2 is connected in the closing direction, a rising current flows through the electric motor 4 as shown in FIG. 2A, and the output signal B from the filter/amplifier circuit 10 rises. Although it slows down a little, it is still possible to start up. Variable resistor 13
The signal C that has passed through has a shape proportional to the signal B and exhibits a lower level than the signal B. On the other hand, the signal D that has passed through the integrating circuit consisting of the resistor 16 and the capacitor 17 has no rising edge and shows a gentle rising curve. Therefore, the level of signal C becomes higher than the level of signal D, and the second comparator circuit 14 outputs a signal at a constant level as shown at E. At this time, the timer 19 does not output a signal during the initial time _t0 , and the first NAND circuit 18 outputs a signal. On the other hand, since the reference voltage set by the variable resistor 8 is set higher than the rising level of the signal B, the first comparator circuit 9 outputs a signal at a constant level, and the indicator lamp 21 It's lit. Therefore, the second NAND circuit 2
Both signals will be input to 0 at the same time,
No signal is output from the NAND circuit 20, the transistor 22 becomes non-conductive, the relay 12 does not operate, the normally closed contact 12a remains closed, and the electric motor 4 continues to rotate. (2) Normal state After the initial time t ₀ of the timer 19 has passed, the signal from the timer 19 is output, but at this time the current flowing to the electric motor 4 is stable and as shown in Figure 2. Signal C is at a lower level than signal D, and no signal is output from the second comparator circuit 14. Therefore, the first NAND circuit 18
Only the signal from the timer 19 is input to the timer 19, and the signal is output. Further, the first comparator circuit 9 outputs a signal in the same way as at the time of startup, and both signals are input to the second NAND circuit 20 at the same time, so no signal is output and the transistor 22 becomes non-conductive, the relay 12 does not operate, and the electric motor 4 continues to rotate. (3) During abnormality When an obstacle such as a human body comes into contact with the opening/closing body and a large load is applied to the electric motor 4, the current flowing through the electric motor 4 increases as shown in the abnormality section A in Fig. 2. do. The output from the filter/amplifier circuit 10 changes in accordance with the change in the current, as shown by B in FIG. 2, and the signal C passing through the variable resistor 13 also changes in proportion to this. On the other hand, the signal D that has passed through the integrating circuit consisting of the resistor 16 and the capacitor 17 becomes a gently rising curve, and the level of the signal C becomes higher than the level of the signal D, and the second comparator circuit 14
A signal is output from. At this time, timer 1
9 is also output, and both signals are input to the first NAND circuit 18 at the same time, so that the first NAND circuit 18 no longer outputs a signal. Further, since the output signal B from the filter/amplifier circuit 10 does not exceed the set reference voltage, the first comparator circuit 9 outputs a signal in the same manner as described above, and the second NAND circuit 20 outputs a signal as described above. Only the signal from the first comparator circuit 9 is input, and the signal is output from the second NAND circuit 20. This output signal causes the transistor 22
conducts, the relay 12 operates, and the normally closed contact 12
a opens, the electric motor 4 stops rotating, and the opening/closing body stops moving. (4) When fully closed Since a large force is required to fully close, the relay 12 is activated and the electric motor 4 is stopped immediately before fully closing, in the same way as in the case of the above-mentioned abnormality. Then, turn off switch 2 and relay 1.
2, the normally closed contact 12a is closed, and then connected again in the closing direction, the timer 19 acts as a delay circuit in the same way as in the startup described above, the abnormality detection circuit no longer operates, and the rising current As a result, the electric motor 4 rotates. When fully closed, a very large load is applied to the electric motor 4, and the output signal from the filter/amplifier circuit 10 exceeds the set reference level.
The signal from the comparison circuit 9 is no longer output,
The indicator lamp 21 goes out. The first NAND circuit 18 outputs a signal as in the case of startup, and only this signal is input to the second NAND circuit 20. The signal is output, transistor 22 becomes conductive, and relay 1
2 is activated, and the electric motor 4 is stopped. This can prevent damage to the electric motor 4 and the opening/closing mechanism of the opening/closing body. The display lamp 21 shows the following information in the above-mentioned abnormality.
It lights up even when the relay 12 is activated and the normally closed contact 12a opens, and it turns off only when the switch is fully closed, so it can also be used as a fully closed confirmation lamp (fully open). The same is true for ). Although the above explanation was for the case where the opening/closing body is closed, the same effect will occur when the opening/closing body is opened. The above operations can be summarized as follows. Note that "1" indicates that there is an output, and "0" indicates that there is an output.
indicates the case where there is no output.

[Table] The diode 15 in the above-mentioned circuit causes the signal D to fall following the fall of the signal C when the load on the electric motor 4 is reduced and the current returns to normal, thereby preventing the next abnormality from occurring. The connection is made to prevent detection failure or detection delay. As this diode 15, it is desirable to use a germanium diode with a small forward voltage drop. Since this invention is configured as described above, it has the following effects. (1) It has good sensitivity, good responsiveness, and reliable operation, so if a human body, etc. is caught in the opening/closing body, the progress of the opening/closing body can be immediately stopped, so the human body, etc. will not be damaged. Also, the opening/closing body side will not be damaged. (2) It is not affected by variations in the characteristics of the electric motor, variations in the operating resistance of the opening/closing body, or changes in operating resistance due to long-term use, and provides highly stable operation without malfunction. (3) There is no need for any modification to the opening/closing body, the opening, the electric motor, and the operating mechanism of the opening/closing body; they are all constructed from electric circuits;
It can be easily attached to existing switchgear. (4) When fully closed, the large torque of the electric motor generated by the starting current can be used to completely close the door, ensuring reliable sealing against rainwater, dust, etc. (5) There is no detection failure or detection delay, and indicator lamps ensure confirmation of fully closed or fully open.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is a graph showing the operation of the circuit shown in FIG. 1... Battery, 2... Changeover switch, 3...
Safety control device, 4... Electric motor, 7... Constant voltage power supply circuit, 9... First comparison circuit, 10... Filter/amplifier circuit, 11... Shunt resistor, 12
... Relay, 12a ... Normally closed contact, 13 ... Variable resistor, 14 ... Second comparison circuit, 16 ... Resistor, 17 ... Capacitor, 18 ... First NAND circuit, 19 ... Timer, 20...second NAND circuit, 22...transistor.

Claims (1)

[Claims] 1 A shunt resistor and relay contacts connected in series to the power supply circuit of the electric motor that drives the switching body, a filter/amplifier circuit with the shunt resistor and relay contacts connected to the input end, and the filter/amplifier a first comparator circuit that compares the output voltage of the circuit with a reference voltage; and an integrator circuit that integrates the output voltage of the filter/amplifier circuit with a lower level level via a variable resistor and the output voltage of the filter/amplifier circuit. a second comparison circuit that compares the voltage after passing;
a timer that generates a constant voltage after a predetermined period of time has elapsed after the start of energization of the electric motor; a first NAND circuit that inputs the output voltage of the timer and the output voltage of the second comparison circuit; a second NAND circuit that inputs the output voltage of the circuit and the output voltage of the first comparison circuit; and a contact that is controlled by the output of the second NAND circuit and connected to the power supply circuit of the electric motor. A safety control device for an electric switchgear, characterized by comprising a relay that opens and closes.