JP2002176795A - Motor control circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable motor driving control by switch operation when leakage is generated in a switch contact part by an accident of sinking under water or the like. SOLUTION: The respective switch signal input ports P1, P2 for comparing the respective voltage signals whose amplitudes change in accordance with operations of switches 5a, 5b for opening and closing a window with a first threshold value and recognizing the signals, and the respective analog signal input ports A1, A2 for inputting the respective voltage signals in parallel, are installed. When water attaches to the switch contact part and input voltages in the respective ports P1, P2 become lower than the first threshold value, switching-over to an emergency mode is performed, and switching operation is judged by comparing the input voltages with a second threshold value lower than a leak voltage at the analog signal input ports. The switching operation can be judged in the case of accident of sinking under water or the like, and the motor driving in accordance with the switching operation can be surely performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a motor control circuit for rotating a motor forward and backward.

[0002]

2. Description of the Related Art Various motor devices are mounted on an automobile, and when the automobile is submerged in water, the motor control circuits may not operate. This is because even if the motor and the control circuit unit are completely waterproof, even if each of the contact points for opening and closing in the power window device leaks due to water in the operation switch unit, for example, both switches are operated. This is because the control circuit cannot recognize an arbitrary switch signal.

FIG. 4 shows an example of a motor control circuit for a power window. In the illustrated example, a window closing up switch 5a and a window opening down switch 5b, and a control unit 11 for controlling the forward / reverse rotation of the power window motor 1 according to the input of the switch signal. The control unit 11 includes a CPU 12 for which control is programmed,
A drive circuit 7 for supplying a drive current to the motor 1 based on a motor control signal output from the CPU 12;
an interface circuit 13 for converting a switch signal from the a · 5b into a signal recognizable by the CPU 6;
A constant voltage circuit 9 is provided as a constant voltage source of the circuit.

In this example, as shown in FIG. 5, when the switches 5a and 5b are not operated and the input ports P1 and P2 of the CPU 12 are in an open state, a constant voltage Vcc A high-level signal is input, and when the switches 5a and 5b are closed, a low-level signal L that is grounded is input to the input ports P1 and P2 of the CPU 12. In response to the input of the low level signal L to each of the input ports P1 and P2, a forward / reverse rotation signal is output from the output ports O1 and O2 of the CPU 12, and a driving current corresponding to the output is output to the motor 1 via the driving circuit 7. It is supposed to be.

[0005]

However, in the above structure, when the operation switch unit itself is submerged, water adheres to the contact portions of the switches 5a and 5b, and as the amount of adhered water increases. As shown in FIG. 5, the input voltage to each of the input ports P1 and P2 decreases. When the input voltage drops below the threshold value Vp for discriminating between high and low levels at both input ports P1 and P2, it is determined that both switches 5a and 5b are operated together. There is a problem that the operation cannot be recognized.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problem, the present invention has been made in order to realize a motor drive control by a switch operation even when a switch contact portion leaks due to a water submersion accident or the like. A first input port connected to a forward switch and a second input port connected to a reverse switch, and a voltage applied to any one of the input ports is a first input port. A motor control circuit that drives the motor to rotate forward or reverse according to the input port to which the input port is applied when the threshold value is lower than the threshold value;
, The second threshold value lower than the leak voltage when water adheres to the switch is set to the first threshold value.
Is used in place of the threshold value.

[0007] According to this, it has been confirmed that water has adhered to the switch due to a submergence accident and the contact portion has been leaked.
It can be determined that the voltage applied to both input ports connected to each switch is lower than the first threshold value for determining the normal switch operation. Since the switch operation state is determined by comparing the low second threshold value with the input voltage, the switch operation can be determined even in the case of a submergence accident, and the motor can be driven according to the switch operation. it can.

Each of the input ports comprises a switch signal input port and an analog signal input port provided in parallel with each of the switches, and the first threshold value is provided at the switch signal input port. According to the comparison with the second threshold value at the analog signal input port, using the switch signal input port for switch operation signal input in the conventional circuit as it is, The circuit can be realized with a simple configuration in which only an analog signal input port is added for discriminating switch operation in the event of a submergence accident.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to specific examples shown in the accompanying drawings.

FIG. 1 is an external view showing a motor unit of a power window device for a vehicle to which the present invention is applied. In the figure, the motor unit has a motor 1, a gear unit 2 connected to the motor 1 by a worm gear, and a control unit 3, and are integrally connected via a case. The forward and reverse rotation of the motor 1 causes the gear unit 2 to rotate.
The sector gear 4 swings via a pinion 2a formed on the shaft of the worm wheel, and the window is opened and closed via a link mechanism (not shown) connected to the sector gear 4. An operation switch box 5 for an occupant to operate when opening and closing the window is connected to the control unit 3 via a wire harness.

FIG. 2 is a circuit diagram schematically showing a main part of a motor control circuit of the power window device according to the present invention. As shown in FIG. 2, in the control unit 3, a CPU 6 programmed to control the present apparatus, a driving circuit 7 for supplying a driving current to the motor 1 by a motor control signal output from the CPU 6, An interface circuit 8 for converting each switch signal from a window closing up switch 5a and a window opening down switch 5b provided in the operation switch box 5 into a signal recognizable by the CPU 6.
And a constant voltage circuit 9 for supplying a constant voltage Vcc of the circuit. In addition, each of the above switches 5a and 5b
Are independently operable switches, which are grounded when closed.

In the circuit of FIG. 2, the CPU 6
As in the example of FIG. 4, each of the switch signal input ports P1 and P2 for recognizing each of the voltage signals whose level changes according to the operation of each of the switches 5a and 5b, and for inputting each of the voltage signals in parallel. Each analog signal input port A1, A2
Are provided. At each of the input ports P1 and P2, as in the example of FIG. 5, the input voltage level is compared with the first threshold value Vp to determine whether each of the switches 5a and 5b has been operated (grounded). Determine.

The control procedure will be described below with reference to FIG. In the control according to the present invention, a normal mode and an emergency mode are provided, and in the normal mode state, when the switches 5a and 5b are not operated, the input ports P1 and P2 are fixed. This is a state where a high-level signal of the voltage Vcc is applied. And down switch 5
When the terminal b is operated, the voltage level of the node A corresponding to the input port P1 is low (L <Vp) due to the ground.
, Whereby a normal rotation drive signal is output from the output ports O1 and O2.
Is supplied to the motor 1 in the forward direction from the
Turns forward and the window opens. When the up switch 5a is operated, the voltage level of the node B corresponding to the input port P2 is determined in the same manner as described above. In this case, the motor 1 rotates in the reverse direction and the window closes.

If the vehicle is submerged in water and enters the switch box 5 and water adheres to the contact portions of the switches 5a and 5b, as described in the conventional example, as the amount of adhered water increases, the amount of adhered water increases. As a result, the voltages of the nodes A and B decrease. When the input voltages to the input ports P1 and P2 are both lower than the first threshold value Vp, the CPU 6 switches from the normal mode to the emergency mode.

In this emergency mode,
Switch 5a at each analog signal input port A1, A2
-The operation state of 5b is determined. As a threshold value for this determination, an arbitrary value lower than the first threshold value Vp and between a leak voltage in a submerged state of each of the switches 5a and 5b and a low level (L) due to grounding. And a second threshold value Vw.

As shown in FIG. 3, when the down switch 5b is operated in the emergency mode, the input of the low level signal L by the ground is compared with the second threshold value Vw as described above. By doing so, it is determined that the down switch 5b has been operated. As a result, the motor drive signal is output from the output ports O1 and O2 by the CPU 6, and the window can be opened by reversing the motor 1.

The submerged state is eliminated and each of the input ports P1.
When both the input voltages to P2 return to the state higher than the first threshold value Vp, the emergency mode is released,
Return to normal mode. In the normal mode other than the emergency mode, the analog signal input port A1.
Changes in the input voltage to A2 are ignored.

In the illustrated example, the up switch 5a
The same control can be performed on the input port P2 and the analog signal input port A2 on the side, and in the event of a submergence accident, not only opening the window for escape but also closing the window is possible. For example, if the switch box is flooded for some reason while driving in heavy rain such as a storm, the window can be closed after opening the window for some reason, and equipment other than the switch box may be closed. This is effective when the vehicle can run normally.

In the illustrated example, the determination of the submerged state is made by the change of the input voltage to the input ports P1 and P2 for digitally determining, but the analog port A1 is used.
・ Only A2, and each threshold value Vp ・ Vw inside the CPU 6
May be changed. For example, in normal times, the first threshold value Vp is compared with the input voltage, and when the input voltages to the respective analog ports A1 and A2 are both lower than the first threshold value Vp, the emergency mode is set and the second mode is set. May be compared with the input voltage.

[0020]

As described above, according to the present invention, the fact that water has adhered to the switch and the contact portion has leaked due to a submersion accident is applied to both input ports connected to each switch. It can be determined that the voltage has become lower than the first threshold value for determining the normal switch operation, and in that case, the input voltage is compared with the second threshold value lower than the leak voltage. Since the switch operation state is determined in this manner, the switch operation can be determined even in the case of a water submergence accident, and the motor drive according to the switch operation can be reliably performed.

Further, a switch signal input port and an analog signal input port are provided in parallel with each other for the forward and reverse switches, and a comparison with a first threshold value is performed at the switch signal input port. Since the comparison with the second threshold value is performed at the analog signal input port, it is possible to use the switch signal input port for inputting the switch operation signal in the conventional circuit as it is to determine the switch operation in the event of a submersion accident or the like. The circuit to be performed can be realized with a simple configuration in which only an analog signal input port is added, and a circuit corresponding to a submergence accident or the like can be easily provided without a significant design change.

[Brief description of the drawings]

FIG. 1 is an external view showing a motor unit of an automotive power window device to which the present invention is applied.

FIG. 2 is a circuit diagram schematically showing a main part of a motor control circuit according to the present invention.

FIG. 3 is an explanatory diagram showing a control procedure by a motor control circuit according to the present invention.

FIG. 4 is a main part schematic circuit diagram showing an example of a circuit of a power window device for an automobile.

FIG. 5 is an explanatory diagram showing a control procedure in the circuit of FIG. 4;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Motor 2 Gear part 3 Control part 4 Sector gear 5 Switch box, 5a Up switch, 5b
Down switch 6 CPU 7 Drive circuit 8 Interface circuit 9 Constant voltage circuit 11 Control unit 12 CPU 13 Interface circuit

Claims (2)

[Claims] A first input port connected to a forward switch and a second input port connected to a reverse switch, wherein a voltage applied to one of the input ports is a first input port; A motor control circuit for driving the motor to rotate forward or reverse according to the input port to which the input port is applied when the voltage is lower than the threshold value, wherein the voltages applied to the input ports are both the first A motor control circuit, wherein when the voltage falls below a threshold value, a second threshold value lower than a leak voltage when water adheres to the switch is used in place of the first threshold value. 2. The switch device according to claim 2, wherein each of the input ports comprises a switch signal input port and an analog signal input port provided in parallel with each of the switches, and wherein the switch signal input port has the first threshold value. The motor control circuit according to claim 1, wherein the comparison is made with the second threshold value at the analog signal input port.