Motor drive device

Abstract

Provided is a motor drive device with which stable circuit operation can be obtained when a vehicle is flooded.　This motor drive device includes: first and second switch units that connect first and second terminals of a motor to a first power supply or a reference potential point; a first operation switch that causes the motor to rotate in a first direction; a water immersion detection circuit that switches the first and second switch units by causing first and second switching elements to operate when water immersion is detected; and a third switching element that is connected to the second switching element. The water immersion detection circuit has a fourth switching element that is conductive during water immersion and outputs a water immersion detection signal. One end of the first operation switch is connected to the third switching element and a control unit, the other end of the first operation switch is connected to the first power supply via the fourth switching element and is connected to a second power supply. When operated during water immersion, the first operation switch connects the first power supply to the third switching element, and the third switching element causes the second switching element to operate and causes the motor to rotate in the first direction.

Description

Motor drive unit

[0001] The present disclosure relates to a motor drive device.

[0002] Conventionally, there has been provided a motor drive circuit including a first switching means for switching one end of the motor to be connected to a power supply or a ground, a second switching means for switching the other end of the motor to be connected to a power supply or a ground, a first operation switch that is operated when rotating the motor in one direction, a second operation switch that is operated when rotating the motor in the other direction, a first switching element that drives the first switching means so that one end of the motor is connected to a power supply and the other end is connected to ground when the first operation switch is operated, a second switching element that drives the second switching means so that one end of the motor is connected to ground and the other end is connected to a power supply when the second operation switch is operated, and a power supply circuit including a first switching element that drives the first operation switch so that one end of the motor is connected to ground and the other end is connected to a power supply when the second operation switch is operated. a control unit that operates the first switching element based on operation of the first operation switch and the second switching element based on operation of the second operation switch, a water flood detection circuit that detects water flooding and outputs a water flood detection signal, and applies the water flood detection signal to a control terminal of the first switching element and a control terminal of the second switching element, respectively, to operate each switching element, and a third switching element that is connected between the control terminal of the second switching element and the first operation switch and that operates when the first operation switch is operated while the water flood detection circuit is outputting the water flood detection signal, thereby prohibiting operation of the second switching element. The third switching element has a control terminal (base) connected to the water flood detection circuit and an emitter connected to the first operation switch (see, for example, Patent Document 1).

[0003] JP 2013-249724 A

[0004] In a conventional motor drive device (power window device), the third switching element, which is an NPN transistor, has a control terminal (base) connected to the flood detection circuit and a current output terminal (emitter) connected to the first operation switch. When the first operation switch is off, the current output terminal (emitter) receives voltage from the battery, but when the first operation switch is on, the current output terminal (emitter) is connected to ground and receives 0 V.

[0005] As described above, in conventional motor drive devices (power window devices), the potential of the current output terminal (emitter) of the third switching element fluctuates greatly, which may cause the operation of the third switching element to become unstable, resulting in unstable circuit operation.

[0006] Therefore, an object of the present invention is to provide a motor drive device that can ensure stable circuit operation when a vehicle is submerged in water.

[0007] A motor drive device according to an embodiment of the present disclosure includes a first switching unit that switches either a first terminal or a second terminal of a motor to be connected to a first power supply or a reference potential point, a second switching unit that switches either the first terminal or the second terminal of the motor to be connected to the first power supply or the reference potential point, a first operation switch that is operated when rotating the motor in a first direction, a second operation switch that is operated when rotating the motor in a second direction, a first switching element that drives the first switching unit, a second switching element that drives the second switching unit, a third switching element that operates the first switching element based on operation of the first operation switch, and operates the second switching element based on operation of the second operation switch. and a water flood detection circuit that outputs a water flood detection signal when it detects water flooding and switches between the first switching unit and the second switching unit by operating the first switching element and the second switching element in response to the water flood detection signal, the water flood detection circuit has a fourth switching element that operates when water flooding occurs and outputs the water flood detection signal, the first operation switch has one end connected to the third switching element and the control unit and the other end connected to the first power source via the fourth switching element and also connected to a second power source, and when the first operation switch is operated when water flooding occurs, the first power source is connected to the third switching element, and the third switching element operates the second switching element, causing the motor to rotate in the first direction.

[0008] It is possible to provide a motor drive device that can obtain stable circuit operation even when the vehicle is submerged in water.

[0009] FIG. 1 is a diagram illustrating an example of the configuration of a motor drive device of an embodiment; FIG. 2 is a diagram illustrating an example of the operation of the motor drive device of an embodiment when not being operated and not submerged in water; FIG. 3 is a diagram illustrating an example of the operation of the motor drive device of an embodiment when not being operated and submerged in water; FIG. 4 is a diagram illustrating an example of the operation of the motor drive device of an embodiment when an UP operation is performed when not submerged in water; FIG. 5 is a diagram illustrating an example of the operation of the motor drive device of an embodiment when an UP operation is performed when submerged in water; FIG. 6 is a diagram illustrating an example of the operation of the motor drive device of an embodiment when an DOWN operation is performed when not submerged in water; FIG. 7 is a diagram illustrating an example of the operation of the motor drive device of an embodiment when an DOWN operation is performed when submerged in water; FIG. 8 is a diagram illustrating an example of the configuration of a motor drive device of a modified embodiment; FIG. 9 is a diagram illustrating an example of the operation of the motor drive device of a modified embodiment when not being operated and not submerged in water; FIG. 10 is a diagram illustrating an example of the operation of the motor drive device of a modified embodiment when not being operated and submerged in water; FIG. 11 is a diagram illustrating an example of the operation of the motor drive device of a modified embodiment when an UP operation is performed when not submerged in water; 10A and 10B are diagrams illustrating an example of the operation of a motor drive device according to a modified example of an embodiment when the DOWN button is pressed when the device is not submerged in water, and FIG. 10C are diagrams illustrating an example of the operation of a motor drive device according to a modified example of an embodiment when the DOWN button is pressed when the device is submerged in water.

[0010] Hereinafter, an embodiment to which the motor drive device of the present disclosure is applied will be described.

[0011] 1 is a diagram showing an example of the configuration of a motor drive device 100 according to an embodiment. The motor drive device 100 is mounted on a vehicle and controls the drive of a motor 10 that drives an opening / closing body such as a window of the vehicle to open and close. Here, the circuit configuration of the motor drive device 100 will be described using FIG. 1.

[0012] Motor 10 has terminals 11 and 12. Terminal 11 is an example of a first terminal, and terminal 12 is an example of a second terminal. The direction in which motor 10 rotates when opening (lowering) the window is an example of a first direction, and the direction in which motor 10 rotates when closing (raising) the window is an example of a second direction.

[0013] When opening (lowering) the window, current is input from relay 111 to motor 10 via terminal 11, and the current flows in the direction from terminal 12 to relay 112, as indicated by the wiring marked “>>DOWN.” When closing (raising) the window, current is input from relay 112 to motor 10 via terminal 12, and the current flows in the direction from terminal 11 to relay 111, as indicated by the wiring marked “>>UP.” The direction in which motor 10 rotates when opening (lowering) the window is an example of the first direction, and the direction in which motor 10 rotates when closing (raising) the window is an example of the second direction.

[0014] 1 shows a power supply VB and a power supply Vcc. The power supply VB is an example of a first power supply, and is supplied with power directly from the vehicle's battery. The voltage of the power supply VB is, for example, 12 V. Even if the vehicle is submerged in water, power is supplied to the power supply VB from the battery.

[0015] The power supply Vcc is an example of a second power supply. The power supply Vcc is supplied by processing the power output from the vehicle's battery using an on-board IC (Integrated Circuit). An example of the on-board IC is an MCU (Micro Controller Unit) 150. The processing performed by the on-board IC includes control processing of a regulator that reduces the power output from the vehicle's battery. The voltage of the power supply Vcc is, for example, 5 V. If the vehicle is flooded and the on-board IC becomes inoperable, the power supply Vcc will no longer be supplied. Note that the power supply Vcc is not limited to 5 V, and may be any voltage capable of driving a transistor Q3, which will be described later. The power supply Vcc may be 12 V, which is the same as the power supply VB.

[0016] <Motor drive device 100> The motor drive device 100 includes a relay device 110, operation switches 120D and 120U, transistors Q1 and Q2, a flood control circuit 130, a flood detection circuit 140, and an MCU 150. The operation switch 120D is an example of a first operation switch, and the operation switch 120U is an example of a second operation switch. The transistor Q1 is an example of a first switching element, and the transistor Q2 is an example of a second switching element. The MCU 150 is an example of a control unit.

[0017] <Relay Device 110> The relay device 110 has relays 111 and 112 and is connected between the power supply VB and ground. The relay 111 is an example of a first switching unit, and the relay 112 is an example of a second switching unit. The ground is an example of a reference potential point. The relays 111 and 112 have an electromagnetic coil and an open / close contact. The relay 111 is connected to a terminal 11 of the motor 10 and connects the terminal 11 to either the power supply VB or ground. The relay 112 is connected to a terminal 12 of the motor 10 and connects the terminal 12 to either the power supply VB or ground.

[0018] The relays 111 and 112 are switched by the transistors Q1 and Q2, respectively. When the transistors Q1 and Q2 are in a non-conductive state (off), the relays 111 and 112 are connected to ground. When the transistor Q1 is on, the relay 111 is connected to the power supply VB. When the transistor Q2 is on, the relay 112 is connected to the power supply VB.

[0019] <Operation Switches 120D, 120U> The operation switch 120D is a switch that an operator operates to open (lower) the window, and the operation switch 120U is a switch that an operator operates to close (raise) the window. The operation switches 120D, 120U are provided, for example, on the doors or center console inside the vehicle.

[0020] One end of each of the operation switches 120D and 120U (the terminals on the left side in FIG. 1) is connected to input terminals 153D and 153U of the MCU 150 via resistors R8 and R10, respectively. Resistors R5 and R7 are inserted in series into a line that branches off from the middle of two wires that connect the operation switches 120D and 120U to the input terminals 153D and 153U via the resistors R8 and R10 and is connected to ground.

[0021] The other ends of the operation switches 120D and 120U (the terminals on the right side in FIG. 1) are connected to the output terminals of the diode circuit 130C of the flood control circuit 130. The other ends of the operation switches 120D and 120U are connected to the power supply VB and the power supply Vcc via the diode circuit 130C.

[0022] <Transistors Q1, Q2> Transistors Q1 and Q2 are, for example, NPN bipolar transistors. The base of transistor Q1 is connected to the output terminal of diode circuit 130A of flood control circuit 130 via resistor R1, the collector is connected to relay 111 of relay device 110, and the emitter is connected to ground.

[0023] The base of transistor Q2 is connected to the output terminal of diode circuit 130B of flood control circuit 130 via resistor R3, the collector is connected to relay 112 of relay device 110, and the emitter is connected to ground. The base of transistor Q2 is an example of the control terminal of the second switching element.

[0024] Note that operating the transistors Q1 and Q2 means controlling the base voltages of the transistors Q1 and Q2 to switch the connection state (conduction state or non-conduction state) between the emitter and collector of the transistors Q1 and Q2. The same applies to the transistors Q3 and Q4.

[0025] <Flooding Control Circuit 130> The flooding control circuit 130 has diode circuits 130A, 130B, and 130C and a transistor Q3. The transistor Q3 is an example of a third switching element. The base of the transistor Q3 is an example of a control terminal of the third switching element. The flooding control circuit 130 is a circuit that controls the motor 10 so that it can be driven even if the MCU 150 becomes inoperable when the vehicle is flooded.

[0026] Each of the diode circuits 130A, 130B, and 130C includes two diodes. In each of the diode circuits 130A, 130B, and 130C, the anodes of the two diodes are connected to different locations, and the cathodes of the two diodes are connected to each other. Therefore, each of the diode circuits 130A, 130B, and 130C outputs a signal that corresponds to the logical sum of the signals input to the two anodes.

[0027] <Diode Circuit 130A> The anode of one diode in the diode circuit 130A (upper side in FIG. 1) is connected to the collector of the transistor Q4 in the water intrusion detection circuit 140, and more specifically, is connected to the power supply VB via the collector-emitter of the transistor Q4. The anode of the other diode in the diode circuit 130A (lower side in FIG. 1) is connected to the output terminal 151 of the MCU 150. The output terminal 151 is a terminal that outputs a signal for lowering the window. The cathodes of the two diodes in the diode circuit 130A are connected to the base of the transistor Q1 via a resistor R1.

[0028] Even if the MCU 150 becomes inoperable when the vehicle is submerged in water, the diode circuit 130A can output the power supplied from the power source VB via the submersion detection circuit 140 to the relay 111.

[0029] <Diode Circuit 130B> The anode of one diode in the diode circuit 130B (upper side in FIG. 1) is connected to the collector of transistor Q4 in the water intrusion detection circuit 140, and more specifically, is connected to power supply VB via the collector-emitter of transistor Q4. The anode of the other diode in the diode circuit 130B (lower side in FIG. 1) is connected to output terminal 152 of the MCU 150. Output terminal 152 is a terminal that outputs a signal to raise the window. The cathodes of the two diodes in the diode circuit 130B are connected to the base of transistor Q2 via resistor R3.

[0030] Even if the MCU 150 becomes inoperable when the vehicle is submerged in water, the diode circuit 130B can output the power supplied from the power source VB to the relay 112 via the submersion detection circuit 140.

[0031] <Diode Circuit 130C> One diode (on the left side in FIG. 1) of the diode circuit 130C is an example of a first diode. The anode of the one diode (on the left side in FIG. 1) of the diode circuit 130C is connected to the collector of the transistor Q4 of the water intrusion detection circuit 140, and more specifically, is connected to the power supply VB via the collector-emitter of the transistor Q4.

[0032] The other diode (on the right side in FIG. 1) of the diode circuit 130C is an example of a second diode. The anode of the other diode (on the right side in FIG. 1) of the diode circuit 130C is connected to the power supply Vcc. The cathodes of the two diodes of the diode circuit 130C are connected to the operation switches 120D and 120U.

[0033] Even if the MCU 150 becomes inoperable when the vehicle is submerged in water and power supply Vcc is no longer supplied, the diode circuit 130C can output power supplied from power supply VB via the flood detection circuit 140 to the base of transistor Q3 via operation switch 120D. Furthermore, when the voltage values ​​of power supply VB and power supply Vcc differ, the diode circuit 130C can prevent backflow between power supply VB and power supply Vcc.

[0034] <Transistor Q3> The transistor Q3 is, for example, an NPN bipolar transistor. The base of the transistor Q3 is connected to one end of the operation switch 120D (the terminal on the left side in FIG. 1 ), the collector is connected to the output terminal of the diode circuit 130B (the cathodes of the two diodes) via a resistor R3, and is also connected to the base of the transistor Q2, and the emitter is connected to ground. The transistor Q3 is a switching element that switches the connection state between the base of the transistor Q2 and ground.

[0035] <Water Flooding Detection Circuit 140> The water flooding detection circuit 140 includes a transistor Q4 and a water flooding detection unit 141. The transistor Q4 is an example of a fourth switching element.

[0036] <Transistor Q4> The transistor Q4 is, for example, a PNP transistor. The base of the transistor Q4 is connected to the water flood detection unit 141, the collector is connected to the anode of one of the diodes in the diode circuits 130A, 130B, and 130C of the water flood control circuit 130, and the emitter is connected to the power supply VB.

[0037] <Water Flooding Detection Unit 141> The water flooding detection unit 141 has two spaced-apart pads inserted in series between the base of transistor Q4 and ground. For example, the water flooding detection unit 141 is located at a predetermined height from the ground, inside a power window motor drive device, etc. When the vehicle is not flooded, there is no electrical continuity between the two pads. Therefore, voltage is supplied to the base of transistor Q4 from power source VB via a resistor connecting the emitter and base, resulting in a non-conductive state between the emitter and collector of transistor Q4. Furthermore, when the vehicle is flooded and water causes electrical continuity between the two pads, the base of transistor Q4 is connected to ground, thereby establishing electrical continuity between the emitter and collector.

[0038] Therefore, when water is flooded, the output of the water flood detection circuit 140 becomes H level as the transistor Q4 becomes conductive. The H level output of the water flood detection circuit 140 is an example of a water flood detection signal. The transistor Q4 outputs a water flood detection signal that is an H level output.

[0039] <MCU 150> The MCU 150 is realized by a computer including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an input / output interface, an internal bus, etc. The MCU 150 has output terminals 151 and 152 and input terminals 153D and 153U.

[0040] Output terminal 151 is connected to the anode of the other diode (lower in FIG. 1) of diode circuit 130A, and outputs a signal for lowering the window. For this reason, output terminal 151 is labeled "DOWN output." Output terminal 152 is connected to the anode of the other diode (lower in FIG. 1) of diode circuit 130B, and outputs a signal for raising the window. For this reason, output terminal 152 is labeled "UP output."

[0041] The input terminal 153D is connected to one end of the operation switch 120D (the terminal on the left in FIG. 1) via a resistor R8. When the operation switch 120D is closed (turned on), an H-level signal is input from the diode circuit 130A, which is supplied with power from the power supply Vcc or VB. This allows the MCU 150 to determine that the operation switch 120D has been operated (that the window has been lowered). The input terminal 153D is labeled "DOWN input."

[0042] Input terminal 153U is connected to one end of operation switch 120U (the terminal on the left in FIG. 1) via resistor R10. When operation switch 120U is closed (turned on), an H-level signal is input from diode circuit 130A, which is supplied with power from power supply Vcc or power supply VB. This allows MCU 150 to determine that operation switch 120U has been operated (that an operation to raise the window has been performed). Input terminal 153U is labeled "UP input."

[0043] When an H-level signal is input to input terminal 153D, MCU 150 determines that operation switch 120D has been operated, and outputs a signal to lower the window from output terminal 151. When an H-level signal is input to input terminal 153U, MCU 150 determines that operation switch 120U has been operated, and outputs a signal to raise the window from output terminal 152.

[0044] 2A is a diagram illustrating an example of the operation of the motor drive device 100 when not in operation and not submerged in water. When not in water, the two pads of the submersion detection unit 141 of the submersion detection circuit 140 are not electrically connected. When not in operation, the operation switches 120D and 120U are not being operated.

[0045] In the following description, the emitter-collector non-conduction of transistors Q1 to Q4 is referred to as "off," and the emitter-collector conductive state is referred to as "on." Furthermore, the rotation of motor 10 in the second direction to raise the window is referred to as "forward rotation of motor 10," and the rotation of motor 10 in the first direction to lower the window is referred to as "reverse rotation of motor 10."

[0046] Since the MCU 150 can operate normally when not submerged in water, the outputs from the output terminals 151 and 152 of the MCU 150 are at L (low) level when not in operation and not submerged in water. Also, the transistor Q4 of the water submersion detection circuit 140 is turned off because the base is at H (high) level due to the supply of power from the power supply VB via the resistor between the emitter and base. Therefore, the output of the water submersion detection circuit 140 is at L level.

[0047] As a result, the output of diode circuit 130A is at L level, turning off transistor Q1. Also, transistor Q3 is turned off because the input to its base is at L level. Also, the output of diode circuit 130B is at L level, turning off transistor Q2.

[0048] When both the transistors Q1 and Q2 are turned off, the relays 111 and 112 are connected to ground, so that no current flows through the motor 10, and the motor 10 is stopped.

[0049] 2B is a diagram illustrating an example of the operation of the motor drive device 100 when the device is not being operated and the device is submerged in water. The submerged state refers to a state in which two pads of the submerged detection unit 141 of the submerged detection circuit 140 are electrically connected.

[0050] When the device is not being operated during flooding, the outputs of output terminals 151 and 152 of MCU 150 will be L level if MCU 150 is operating normally, and will be in an indeterminate state that is neither H level nor L level if MCU 150 is inoperable. For this reason, the output levels of output terminals 151 and 152 are shown in parentheses in Figure 2B.

[0051] Furthermore, the transistor Q4 of the water inundation detection circuit 140 is turned on because the base of the transistor Q4 is at L level when the two pads of the water inundation detection unit 141 are conductive. As a result, the output of the water inundation detection circuit 140 becomes H level based on the output of the power supply VB.

[0052] As a result, an H-level signal is supplied to the diode of one of the diode circuits 130A and 130B (the upper side in FIG. 2B). That is, whether the MCU 150 is operating normally or inoperable, an H-level signal is input to the diode of one of the diode circuits 130A and 130B (the upper side in FIG. 2B).

[0053] At this time, since the switch is not being operated, the input to the base of transistor Q3 is at L level, turning transistor Q3 off. As a result, the bases of transistors Q1 and Q2 become H level, turning both transistors Q1 and Q2 on.

[0054] When both transistors Q1 and Q2 are turned on, both relays 111 and 112 are switched on and connected to power supply VB. As a result, terminals 11 and 12 of motor 10 have the same potential, and no current flows through motor 10, causing motor 10 to stop. When not in operation during flooding, motor 10 is stopped with power supplied from power supply VB to both terminals 11 and 12 of motor 10. Because power supply VB is directly connected to the vehicle's battery, power is supplied even during flooding.

[0055] 3A is a diagram illustrating an example of the operation of the motor drive device 100 during the UP operation when the vehicle is not submerged in water. The UP operation is an operation in which the operator operates the operation switch 120U to raise the window.

[0056] Since the MCU 150 can operate normally when the device is not submerged, when the UP operation is performed when the device is not submerged, the MCU 150 determines that the UP operation is being performed based on the input signal at input terminal 153U, and sets the output at output terminal 151 to L level and the output at output terminal 152 to H level. Furthermore, transistor Q4 of the water submersion detection circuit 140 is turned off because its base is at H level due to power being supplied from power source VB via a resistor between the emitter and base. Therefore, the output of diode circuit 130A is at L level, and transistor Q1 is turned off. Furthermore, transistor Q3 is turned off because its base input is at L level. Furthermore, the output of diode circuit 130B is at H level, and transistor Q3 is off, so transistor Q2 is turned on.

[0057] When transistor Q1 is turned off and transistor Q2 is turned on, relay 112 switches from a state in which both relays 111 and 112 are connected to ground (a state in which they are not operated when not submerged in water) to a state in which relay 112 is connected to power supply VB. As a result, current flows from relay 112 to terminal 12, terminal 11, and relay 111, causing motor 10 to rotate forward, raising the window.

[0058] <Operation During UP Operation When Submerged in Water> FIG. 3B is a diagram illustrating an example of the operation of motor drive device 100 during UP operation when submerged in water.

[0059] During UP during flooding, if MCU 150 is operating normally, the output of output terminal 151 of MCU 150 will be L level, and the output of output terminal 152 will be H level. If MCU 150 is inoperable, the outputs of output terminals 151 and 152 will be in an indefinite state, neither H level nor L level. For this reason, in Figure 3B, the output levels of output terminals 151 and 152 are shown in parentheses.

[0060] Furthermore, the transistor Q4 of the water inundation detection circuit 140 is turned on because the base goes low when the two pads of the water inundation detection unit 141 become conductive, causing the output of the water inundation detection circuit 140 to go high.

[0061] As a result, an H-level signal is supplied to the diode of one of the diode circuits 130A and 130B (the upper side in FIG. 2B). That is, whether the MCU 150 is operating normally or inoperable, an H-level signal is input to the diode of one of the diode circuits 130A and 130B (the upper side in FIG. 2B).

[0062] At this time, since the UP operation is in progress, the input to the base of transistor Q3 is at L level, turning transistor Q3 off. As a result, the bases of transistors Q1 and Q2 become H level, turning both transistors Q1 and Q2 on.

[0063] When both transistors Q1 and Q2 are on, both relays 111 and 112 are connected to power supply VB, and as a result, motor 10 is stopped with power supplied from power supply VB to both terminals 11 and 12 of motor 10.

[0064] If the UP operation is performed when the motor 10 is not being operated during flooding, power is supplied from the power source VB to both terminals 11 and 12 of the motor 10, and the motor 10 is therefore maintained in a stopped state. Therefore, even if the UP operation is performed accidentally when the window is somewhat open during flooding, the window will not close and will remain somewhat open.

[0065] Furthermore, when the state switches from a non-flooded state to a flooded state while the UP switch is in operation, the motor 10, which had been rotating forward, is stopped by maintaining a state in which power is supplied from the power source VB to both terminals 11 and 12 of the motor 10. Therefore, the motor 10 stops when the state switches to the flooded state, and if the window is open to some extent at that time, it will remain open.

[0066] 4A is a diagram illustrating an example of the operation of the motor drive device 100 during a DOWN operation when the vehicle is not submerged in water. The DOWN operation is an operation in which the operator operates the operation switch 120D to lower the window.

[0067] Since the MCU 150 can operate normally when the vehicle is not flooded, when the DOWN operation is performed when the vehicle is not flooded, the MCU 150 determines that the DOWN operation is being performed based on the input signal at input terminal 153D, and sets the output at output terminal 151 to H level and the output at output terminal 152 to L level. Furthermore, transistor Q4 of the flood detection circuit 140 is turned off because its base is at H level due to power supplied from power supply VB via a resistor between the emitter and base. Therefore, the output of diode circuit 130A is at H level, and transistor Q1 is turned on. Furthermore, transistor Q3 is turned on because the input to its base is at H level. This is because power is supplied to the base of transistor Q3 from power supply Vcc. Furthermore, the output of diode circuit 130B is at L level, and transistor Q3 is on. In this state, transistor Q2 is turned off.

[0068] When transistor Q1 is on and transistor Q2 is off, relay 111 switches from a state in which both relays 111 and 112 are connected to ground (a state in which they are not operated when not submerged in water) to a state in which relay 111 is connected to power supply VB. As a result, current flows from relay 111 to terminals 11 and 12 and relay 112, causing motor 10 to rotate in the reverse direction, lowering the window.

[0069] <Operation when DOWN operation is performed when flooded> FIG. 4B is a diagram illustrating an example of the operation of motor drive device 100 when DOWN operation is performed when flooded.

[0070] During a DOWN state due to flooding, if MCU 150 is operating normally, the output of output terminal 151 of MCU 150 will be H level, and the output of output terminal 152 will be L level. If MCU 150 is inoperable, the outputs of output terminals 151 and 152 will be in an indeterminate state, neither H level nor L level. For this reason, in Figure 4B, the output levels of output terminals 151 and 152 are shown in parentheses.

[0071] Furthermore, when the two pads of the water inundation detection unit 141 become conductive, the base of transistor Q4 of the water inundation detection circuit 140 becomes low, turning it on. As a result, the output of the water inundation detection circuit 140 becomes high. As a result, a high-level signal is supplied to the diode of one of the diode circuits 130A and 130B (the upper side in FIG. 2B). In other words, whether the MCU 150 is operating normally or inoperable, a high-level signal is input to the diode of one of the diode circuits 130A and 130B (the upper side in FIG. 2B).

[0072] Also, since the DOWN operation is in progress, the input to the base of transistor Q3 becomes H level. This is because power supply VB is supplied to the anode of one diode of diode circuit 130C (left side in FIG. 4B) via water intrusion detection circuit 140, and the power of power supply VB is input to the base of transistor Q3 as an H level signal. At this time, if MCU 150 is operating normally, power supply Vcc is supplied to the anode of the other diode of diode circuit 130C (right side in FIG. 4B). If MCU 150 is inoperable, power supply Vcc is not supplied, but power supply VB is supplied to the anode of the diode of one diode of diode circuit 130C (left side in FIG. 4B). As a result, regardless of whether power supply Vcc is supplied, diode circuit 130C outputs an H level signal based on power supply VB to the base of transistor Q3.

[0073] As a result, transistor Q3 turns on, and the base of transistor Q2 goes to L level because it is connected to ground via the emitter-collector of transistor Q3. As a result, the base of transistor Q1 goes to H level, the base of transistor Q2 goes to L level, transistor Q1 turns on, and transistor Q2 turns off.

[0074] When transistor Q1 is on and transistor Q2 is off, relay 111 is connected to power supply VB and relay 112 is connected to ground. As a result, current flows from relay 111 to terminals 11 and 12 and relay 112, causing motor 10 to rotate in the reverse direction, lowering the window. In other words, when operation switch 120D is operated during flooding, power supply VB is connected to transistor Q3, which operates transistor Q2, causing motor 10 to rotate in the first direction (DOWN direction).

[0075] If the DOWN operation is performed after the vehicle was not being operated during flooding, the relay 112 switches from a state in which power is supplied from the power source VB to both terminals 11 and 12 of the motor 10 to ground, causing the motor 10 to rotate in the reverse direction and lower the window. Since current flows to the motor 10 by switching the relay 112 to ground from a state in which power is supplied from the power source VB to both terminals 11 and 12 of the motor 10, the motor 10 can be reversed and the window can be lowered more reliably and stably than if current were to flow to the motor 10 from a state in which power is not being supplied to both terminals 11 and 12 of the motor 10.

[0076] Furthermore, when the state is switched from a DOWN operation when the vehicle is not flooded to a flooded state, relays 111 and 112 do not switch, and motor 10 can be reversed to lower the window while maintaining the connection state of relays 111 and 112 when the DOWN operation is performed when the vehicle is not flooded.

[0077] The above describes a configuration in which relays 111 and 112 are both connected to ground when not operated and not submerged in water, and are both connected to power supply VB when not operated and submerged in water. However, a configuration in which relays 111 and 112 are both connected to power supply VB when not operated and not submerged in water, and are both connected to ground when not operated and submerged in water, may also be used. In this case, for example, the connections in the connection paths from transistors Q2 and Q3 to terminals 11 and 12 of motor 10 are swapped. More specifically, the connections between relays 111 and 112 and terminals 11 and 12 of motor 10 are swapped, and relay 112 is switched to connect to power supply VB when the DOWN operation is performed when submerged in water.

[0078] <Motor drive device 100M according to a modified example of the embodiment> Figure 5 is a diagram showing an example of a motor drive device 100M according to a modified example of the embodiment. The motor drive device 100M is mounted on a vehicle and controls the drive of a motor 10 that drives an opening / closing body such as a window of the vehicle to open and close. Here, the circuit configuration of the motor drive device 100M will be described using Figure 5. Furthermore, the same reference numerals are used for components that are the same as the components of the motor drive device 100 shown in Figure 1, and descriptions thereof will be omitted.

[0079] Motor driving device 100M has a configuration in which transistor Q3 of motor driving device 100 shown in FIG. 1 is changed to a PNP bipolar transistor and the connections are changed.

[0080] Motor driving device 100M is the same as transistor Q3 of motor driving device 100 shown in FIG. 1 in that the base of transistor Q3 is connected to one end (the left terminal in FIG. 5) of operating switch 120D.

[0081] In motor driving device 100M, the collector and emitter of transistor Q3 are connected to different locations than transistor Q3 of motor driving device 100 shown in FIG.

[0082] In motor driving device 100M, the emitter of transistor Q3 is connected to the output terminal of diode circuit 130B, and the collector is connected to the base of transistor Q2.

[0083] <Operation when not submerged and not in operation> FIG. 6A is a diagram illustrating an example of the operation of motor drive device 100M when not submerged and not in operation.

[0084] Since the MCU 150 can operate normally when not submerged in water, the outputs from the output terminals 151 and 152 of the MCU 150 are at L level when not being operated and not submerged in water. Also, the transistor Q4 of the water submersion detection circuit 140 is turned off because the base is at H level due to the supply of power from the power supply VB via the resistor between the emitter and base. As a result, the output of the water submersion detection circuit 140 is at L level.

[0085] As a result, the output of diode circuit 130A is at L level, turning off transistor Q1. Also, because the output of diode circuit 130B is at L level, the input to the emitter of transistor Q3 is at L level, and the input to the base is also at L level, turning off transistor Q3. As a result, the base of transistor Q2 is at L level, turning off transistor Q2.

[0086] When both the transistors Q1 and Q2 are turned off, the relays 111 and 112 are connected to ground, so that no current flows through the motor 10, and the motor 10 is stopped.

[0087] <Operation when not in operation when submerged in water> FIG. 6B is a diagram illustrating an example of the operation of motor drive device 100M when not in operation when submerged in water.

[0088] When the device is not being operated during flooding, the outputs of output terminals 151 and 152 of MCU 150 will be L level if MCU 150 is operating normally, and will be in an indeterminate state that is neither H level nor L level if MCU 150 is inoperable. For this reason, the output levels of output terminals 151 and 152 are shown in parentheses in Figure 6B.

[0089] Furthermore, the transistor Q4 of the water inundation detection circuit 140 is turned on because the base goes low when the two pads of the water inundation detection unit 141 become conductive, causing the output of the water inundation detection circuit 140 to go high.

[0090] As a result, an H-level signal is supplied to the diode of one of the diode circuits 130A and 130B (the upper side in FIG. 6B). That is, whether the MCU 150 is operating normally or inoperable, an H-level signal is input to the diode of one of the diode circuits 130A and 130B (the upper side in FIG. 2B).

[0091] At this time, since the switch is not being operated, the input to the base of transistor Q3 is at L level, turning transistor Q3 on. As a result, the bases of transistors Q1 and Q2 become H level, turning both transistors Q1 and Q2 on.

[0092] When both transistors Q1 and Q2 are turned on, both relays 111 and 112 are switched on and connected to power supply VB. As a result, terminals 11 and 12 of motor 10 have the same potential, and no current flows through motor 10, causing motor 10 to stop. When not in operation during flooding, motor 10 is stopped with power supplied from power supply VB to both terminals 11 and 12 of motor 10. Because power supply VB is directly connected to the vehicle's battery, power is supplied even during flooding.

[0093] <Operation During UP Operation When Not Submerged> FIG. 7A is a diagram illustrating an example of the operation of motor drive device 100M during UP operation when not submerged.

[0094] When the UP button is pressed when the device is not submerged in water, the output of output terminal 151 becomes L level and the output of output terminal 152 becomes H level, just as when the UP button is pressed when the device is not submerged in water in motor drive device 100 (see FIG. 3A). Because there is no submersion in water, the output of water submersion detection circuit 140 is L level.

[0095] Therefore, the output of diode circuit 130A is at L level, and transistor Q1 is turned off. Also, transistor Q3 is turned on because the input to its base is at L level. Also, the output of diode circuit 130B is at H level, and transistor Q3 is on, and transistor Q2 is turned on.

[0096] When transistor Q1 is turned off and transistor Q2 is turned on, relay 112 switches from a state in which both relays 111 and 112 are connected to ground (a state in which they are not operated when not submerged in water) to a state in which relay 112 is connected to power supply VB. As a result, current flows from relay 112 to terminal 12, terminal 11, and relay 111, causing motor 10 to rotate forward, raising the window.

[0097] <Operation During UP Operation When Submerged in Water> FIG. 7B is a diagram illustrating an example of the operation of motor drive device 100M during UP operation when submerged in water.

[0098] During UP during flooding, if MCU 150 is operating normally, the output of output terminal 151 of MCU 150 will be L level, and the output of output terminal 152 will be H level. If MCU 150 is inoperable, the outputs of output terminals 151 and 152 will be in an indeterminate state, neither H level nor L level. For this reason, in Figure 7B, the output levels of output terminals 151 and 152 are shown in parentheses.

[0099] Furthermore, when water is present, the transistor Q4 of the water flood detection circuit 140 turns on, causing the output of the water flood detection circuit 140 to go high.

[0100] As a result, an H-level signal is supplied to the diode of one of the diode circuits 130A and 130B (the upper side in FIG. 7B). That is, whether the MCU 150 is operating normally or inoperable, an H-level signal is input to the diode of one of the diode circuits 130A and 130B (the upper side in FIG. 7B).

[0101] At this time, since the UP operation is in progress, the input to the base of transistor Q3 is at L level, turning transistor Q3 on. As a result, the bases of transistors Q1 and Q2 become H level, turning both transistors Q1 and Q2 on.

[0102] When both transistors Q1 and Q2 are on, both relays 111 and 112 are connected to power supply VB, and as a result, motor 10 is stopped with power supplied from power supply VB to both terminals 11 and 12 of motor 10.

[0103] That is, when the UP button is pressed in motor drive device 100M while the vehicle is submerged in water, the same operation and effect are obtained as when the UP button is pressed in motor drive device 100 while the vehicle is submerged in water (see FIG. 3B).

[0104] <Operation During DOWN Operation When Not Submerged> FIG. 8A is a diagram illustrating an example of the operation of motor drive device 100M during the DOWN operation when not submerged.

[0105] When the DOWN button is pressed when the vehicle is not submerged in water, the output of output terminal 151 becomes H level and the output of output terminal 152 becomes L level, just as when the DOWN button is pressed when the vehicle is not submerged in water (see FIG. 4A) in motor drive device 100. Since there is no submersion in water, the output of water submersion detection circuit 140 is L level.

[0106] As a result, the output of diode circuit 130A is at H level, turning transistor Q1 on. Also, transistor Q3 is turned off because the input to its emitter is at L level and the input to its base is at H level. This is because power is supplied to the base of transistor Q3 from power supply Vcc and an L level is input from diode circuit 130B. Also, because transistor Q3 is off, the base of transistor Q2 is at L level, turning transistor Q2 off.

[0107] When transistor Q1 is on and transistor Q2 is off, relay 111 switches from a state in which both relays 111 and 112 are connected to ground (a state in which they are not operated when not submerged in water) to a state in which relay 111 is connected to power supply VB. As a result, current flows from relay 111 to terminals 11 and 12 and relay 112, causing motor 10 to rotate in the reverse direction, lowering the window.

[0108] <Operation When DOWN Operation is Performed When the Vehicle is Submerged in Water> FIG. 8B is a diagram illustrating an example of the operation of motor drive device 100M when the DOWN operation is performed when the vehicle is submerged in water.

[0109] When the DOWN operation is performed when the motor drive device 100 is flooded (see FIG. 4B), if the MCU 150 is operating normally, the output of the output terminal 151 of the MCU 150 will be H level and the output of the output terminal 152 will be L level. If the MCU 150 is inoperable, the outputs of the output terminals 151 and 152 will be in an indefinite state that is neither H level nor L level. For this reason, in FIG. 8B, the output levels of the output terminals 151 and 152 are shown in parentheses.

[0110] Furthermore, because water has flooded the system, the output of the water flood detection circuit 140 becomes H level. As a result, an H level signal is supplied to the diode in one of the diode circuits 130A and 130B (the upper side in FIG. 2B ). In other words, whether the MCU 150 is operating normally or inoperable, an H level signal is input to the diode in one of the diode circuits 130A and 130B (the upper side in FIG. 2B ).

[0111] Also, since the DOWN operation is in progress, the input to the base of transistor Q3 becomes H level. This is because power supply VB is supplied to the anode of one diode of diode circuit 130C (left side in FIG. 4B) via water intrusion detection circuit 140, and the power of power supply VB is input to the base of transistor Q3 as an H level signal. At this time, if MCU 150 is operating normally, power supply Vcc is supplied to the anode of the other diode of diode circuit 130C (right side in FIG. 4B). If MCU 150 is inoperable, power supply Vcc is not supplied, but power supply VB is supplied to the anode of the diode of one diode of diode circuit 130C (left side in FIG. 4B). As a result, regardless of whether power supply Vcc is supplied, diode circuit 130C outputs an H level signal based on power supply VB to the base of transistor Q3.

[0112] As a result, transistor Q3 turns off, and an L level is input to the base of transistor Q2, so that the base of transistor Q1 becomes H level and the base of transistor Q2 becomes L level, turning transistor Q1 on and transistor Q2 off.

[0113] When transistor Q1 is on and transistor Q2 is off, relay 111 is connected to power supply VB and relay 112 is connected to ground. That is, the operation of relay 112 can be stopped so that relay 112 is not connected to power supply VB. As a result, current flows from relay 111 to terminal 11, terminal 12, and relay 112, and motor 10 rotates in the reverse direction, lowering the window.

[0114] That is, when the DOWN button is pressed in motor drive device 100M when the device is submerged in water, the same operation and effect are obtained as when the DOWN button is pressed in motor drive device 100 when the device is submerged in water (see FIG. 4B).

[0115] The above describes a configuration in which relays 111 and 112 are both connected to ground when not operated and not submerged in water, and are both connected to power supply VB when not operated and submerged in water. However, a configuration in which relays 111 and 112 are both connected to power supply VB when not operated and not submerged in water, and are both connected to ground when not operated and submerged in water, may also be used. In this case, for example, the connections in the connection paths from transistors Q2 and Q3 to terminals 11 and 12 of motor 10 are swapped. More specifically, the connections between relays 111 and 112 and terminals 11 and 12 of motor 10 are swapped, and relay 112 is switched to connect to power supply VB when the DOWN operation is performed when submerged in water.

[0116] <Effects> The motor drive device 100 includes a relay 111 (first switching unit) that switches either the terminal 11 (first terminal) or the terminal 12 (second terminal) of the motor 10 to be connected to the power supply VB (first power supply) or the ground (reference potential point), a relay 112 (second switching unit) that switches either the terminal 11 (first terminal) or the terminal 12 (second terminal) of the motor 10 to be connected to the power supply VB or the ground, an operation switch 120D (first operation switch) that is operated to rotate the motor 10 in a first direction (DOWN direction), an operation switch 120U that is operated to rotate the motor 10 in a second direction (UP direction), a transistor Q1 (first switching element) that drives the relay 111, a transistor Q2 (second switching element) that drives the relay 112, a transistor Q3 (third switching element) that is connected to the transistor Q2, and a transistor Q4 (third switching element) that switches the operation of the operation switch 120D based on the operation of the operation switch 120D. The control unit 120D includes an MCU 150 (control unit) that operates a transistor Q1 in response to the operation of the operation switch 120U and operates a transistor Q2 in response to the operation of the operation switch 120U, and a water flood detection circuit 140 that outputs a water flood detection signal when it detects water flooding and switches the relays 111 and 112 by operating the transistors Q1 and Q2 in response to the water flood detection signal. The water flood detection circuit 140 has a transistor Q4 (fourth switching element) that operates in the event of water flooding and outputs the water flood detection signal. The operation switch 120D has one end connected to the transistor Q3 and the MCU 150, and the other end connected to a power supply VB via the transistor Q4 and to a power supply Vcc (second power supply). When the operation switch 120D is operated in the event of water flooding, the power supply VB is connected to the transistor Q3, and the transistor Q3 operates the transistor Q1 or the transistor Q2, causing the motor 10 to rotate in the first direction (DOWN direction).

[0117] In this way, when operated during flooding, power supply VB is connected to transistor Q3, which operates transistor Q1 or transistor Q2, causing motor 10 to rotate in the first direction (DOWN direction), allowing transistor Q3 to operate stably and stabilizing the circuit operation of motor drive device 100.

[0118] Therefore, it is possible to provide the motor drive device 100 that can provide stable circuit operation even when the vehicle is submerged in water.

[0119] The vehicle may further include a first diode (the diode on the left side of the diode circuit 130C) connected between the operation switch 120D and the power supply VB, and a second diode (the diode on the right side of the diode circuit 130C) connected between the operation switch 120D and the power supply Vcc. When the vehicle is submerged in water, connecting the first power supply to the operation switch 120D via the first diode (the diode on the left side of the diode circuit 130C) causes the transistor Q3 to operate the transistor Q1 or the transistor Q2, causing the motor 10 to rotate in the first direction (DOWN direction). Furthermore, the use of the first and second diodes prevents backflow even when the voltages of the power supplies VB and Vcc are different.

[0120] Furthermore, transistor Q3 may be a switching element that switches the connection state between transistor Q2 and ground. In motor drive device 100, when transistor Q3 is conductive, transistor Q2 is connected to ground, thereby stopping the operation of relay 112 so that relay 112 does not switch. As a result, motor 10 can be rotated in the first direction (DOWN direction).

[0121] Alternatively, one end of an operating switch 120D may be connected to the control terminal of transistor Q3, and when operating switch 120D during flooding, power supply VB is connected to the base (control terminal) of transistor Q3, causing transistor Q3 to conduct and connecting the control terminal of transistor Q2 to ground, thereby bringing transistor Q2 into a non-conductive state. Because power supply VB is connected to the base of transistor Q3 via operating switch 120D, the operation of transistor Q3 is stable.

[0122] Furthermore, the transistor Q3 may be a switching element that switches the connection state between the transistor Q2 and the MCU 150 and the water submersion detection circuit 140. In the modified motor drive device 100M, the transistor Q3 switches the connection state between the transistor Q2 and the MCU 150, thereby stopping the operation of the relay 112 so that the relay 112 is not connected to the power supply VB. As a result, the motor 10 can be rotated in the first direction (DOWN direction).

[0123] Furthermore, one end of the operation switch 120D is connected to the base of the transistor Q3, and the connection point between the base of the transistor Q3 and one end of the operation switch 120D is connected to ground via a resistor R5, so that when the operation switch 120D is operated during flooding, the base of the transistor Q3 is connected to the power supply VB, causing the transistor Q3 to enter a non-conductive state, which in turn causes the connection between the base of the transistor Q2 and the water flood detection circuit 140 to become non-conductive, thereby causing the transistor Q2 to enter a non-conductive state. When the DOWN operation is performed during flooding, the motor 10 can be rotated in the first direction (DOWN direction) by switching the relay 112 to ground.

[0124] The above describes a motor drive device according to an exemplary embodiment of the present disclosure. However, the present disclosure is not limited to the specifically disclosed embodiment, and various modifications and changes are possible without departing from the scope of the claims.

[0125] This international application claims priority based on Japanese Patent Application No. 2023-168410, filed on September 28, 2023, the entire contents of which are incorporated herein by reference.

[0126] 100 Motor drive device 111, 112 Relays (an example of a first switching unit and a second switching unit) 120D, 120U Operation switches (an example of a first operation switch and a second operation switch) Q1 to Q4 Transistors (an example of a first switching element to a fourth switching element) 130 Flood control circuit 130A, 130B, 130C Diode circuit 140 Flood detection circuit 150 MCU (an example of a control unit)

Claims

a control unit which operates the first switching element based on the operation of the first operation switch and operates the second switching element based on the operation of the second operation switch; and a water flood detection circuit which outputs a water flood detection signal when water flooding is detected and switches the first switching element and the second switching element in response to the water flood detection signal, the water flood detection circuit having a fourth switching element which operates when water flooding is detected and outputs the water flood detection signal, the first operation switch has one end connected to the third switching element and the control unit, and the other end connected to the first power source via the fourth switching element and to a second power source, when the first operation switch is operated while the vehicle is submerged in water, the first power source is connected to the third switching element, and the third switching element operates the second switching element, thereby rotating the motor in the first direction, said motor drive device.

2. The motor drive device of claim 1, further comprising: a first diode connected between the first operating switch and the first power supply; and a second diode connected between the first operating switch and the second power supply.

3. The motor drive device according to claim 1 or 2, wherein the third switching element is a switching element that switches a connection state between the second switching element and the reference potential point.

4. The motor drive device of claim 3, wherein the one end of the first operating switch is connected to a control terminal of the third switching element, and when the first operating switch is operated during flooding, the first power source is connected to the control terminal of the third switching element, the third switching element becomes conductive, and the control terminal of the second switching element is connected to the reference potential point, thereby bringing the second switching element into a non-conductive state.

5. The motor drive device according to claim 1 or 2, wherein the third switching element is a switching element that switches a connection state between the second switching element and the control unit and the water submersion detection circuit.

6. The motor drive device of claim 5, wherein the one end of the first operation switch is connected to the control terminal of the third switching element, and the connection point between the control terminal of the third switching element and the one end of the first operation switch is connected to the reference potential point via a resistor, and when the first operation switch is operated during flooding, the first power source is connected to the control terminal of the third switching element, the third switching element is brought into a non-conductive state, and the connection between the control terminal of the second switching element and the water flood detection circuit is made non-conductive, thereby bringing the second switching element into a non-conductive state.

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