JP6170807B2 - Motor control device - Google Patents

Description

  The present invention relates to a motor control device.

  In a device having a circuit on which a semiconductor such as a microcomputer is mounted, when the user operates the switch, ESD (Electro-Static Discharge) is generated through which static electricity accumulated in the user's body flows through the switch. May damage the semiconductor. Patent Document 1 discloses a technique for preventing ESD to a circuit by disposing a capacitor between a switch and a microcomputer to absorb static electricity.

  Further, in a motor control device related to a power window device in a vehicle such as a passenger car, ESD to the circuit is prevented by using a technique having the same concept as the technique of Patent Document 1 described above. FIG. 5 shows a motor control apparatus 100 in which ESD countermeasure capacitors 192A and 192B are provided between a microcomputer 130 for controlling the rotation of the power window motor 30 and a power window switch (hereinafter referred to as “P / W switch”) 14. It is a figure which shows an example of a circuit. In FIG. 5, an ESD countermeasure capacitor 192A having one end grounded is connected between the UP switch 14A for raising the window glass of the vehicle and the UP input port 118A of the microcomputer 130. In FIG. 5, an ESD countermeasure capacitor 192 </ b> B having one end grounded is connected between the DOWN switch 14 </ b> B for lowering the window glass of the vehicle and the DOWN input port 118 </ b> B of the microcomputer 130.

  Further, in the microcomputer 130 shown in FIG. 5, a vehicle-side body ECU (Electronic Control Unit) 16 is connected to the LIN input port 118 </ b> C via a choke coil 194 and a LIN driver 174. The LIN driver 174 is a device that performs communication control of a LIN (Local Interconnect Network) that is a protocol used for control of a power window device or the like.

  The microcomputer 130 is applied with a control voltage from the 5V regulator 172, and drives the relay 162 to the relay driver 164 based on commands input from the UP input port 118A, the DOWN input port 118B, and the LIN input port 118C. A control command is transmitted. The relay driver 164 rotates the power window motor 30 by driving a relay 162 that turns on or off the power supplied to the motor based on a control command from the microcomputer 130, and the Hall IC 66 controls the rotation speed of the power window motor 30. A signal corresponding to the rotational speed of the power window motor 30 is output. The signal output from the Hall IC 66 is fed back to the microcomputer 130 via the dark current reduction circuit 168 that reduces the dark current included in the signal. Since the microcomputer 70 and the like are vulnerable to ESD, the ESD countermeasure capacitors 192A and 192B absorb the ESD electrical energy.

JP 2001-7455 A

  However, in the technique described in Patent Document 1 and the motor control device shown in FIG. 5, the electrical energy stored in the capacitor for preventing ESD becomes an inrush current when the switch is turned on, and the circuit elements and The switch contacts could be damaged.

  Further, the technique described in Patent Document 1 and the motor control device shown in FIG. 5 have a problem that it takes cost and trouble to mount a capacitor for preventing ESD in a circuit.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a motor control device that can prevent damage to elements due to a high voltage of an inrush current at the time of ESD and switching on with a simple configuration.

In order to solve the above-described problem, the motor control device according to claim 1 is provided between a control unit that controls rotation of a motor based on an operation of a switch, the control unit, and the switch. A signal converting means for converting an analog signal input from the digital signal into the control means, and one end connected between the switch and the signal converting means and the other end grounded, and the analog signal A bidirectional Zener diode that discharges to the ground side when the voltage of the voltage exceeds the breakdown voltage, and one end is connected between one end of the bidirectional Zener diode and the signal conversion means, and the other end is grounded, And a high voltage circuit having a clamp circuit that suppresses the voltage of the analog signal input to the signal conversion means to a predetermined voltage or lower .

  According to this motor control device, the high withstand voltage circuit that can withstand the high voltage applied from the switch side at the time of ESD or switch-on is provided in the front stage of the control means. Further, since the control means and the high withstand voltage circuit are integrated into one integrated circuit, the number of parts can be reduced and the cost can be reduced, and the circuit board of the motor control device can be made compact. As a result, the device can be prevented from being damaged by a high voltage of the inrush current at the time of ESD and switching on with a simple configuration.

Further, according to this motor control device, the voltage applied to the high withstand voltage circuit can be discharged to the GND via the bidirectional Zener diode, and the element can be prevented from being damaged due to the high voltage of the inrush current at the time of ESD and switching on. .

Further, according to this motor control device, the voltage of the analog signal input to the signal conversion means can be suppressed to a predetermined voltage or less by the clamp circuit.

The motor control device according to claim 2 is the motor control device according to claim 1 , further comprising a first resistor between the switch and the bidirectional Zener diode of the high voltage circuit. The circuit further includes a second resistor having a resistance value larger than that of the first resistor between the bidirectional Zener diode and the clamp circuit .

  According to this motor control device, the first resistor, the bidirectional Zener diode, and the second resistor constitute a kind of voltage dividing circuit, and the resistance value of the second resistor is set to be higher than that of the first resistor. By increasing the voltage, the applied high voltage can be largely divided toward the bidirectional Zener diode. As a result, the device can be prevented from being damaged by a high voltage of the inrush current at the time of ESD and switching on with a simple configuration.

The motor control device according to claim 3 is the motor control device according to claim 1 or 2 , wherein a gate, a source, and a back gate are short-circuited instead of the bidirectional Zener diode, and a drain is connected to the switch and the signal. An NMOSFET is connected between the conversion means and the source is grounded.

  According to this motor control device, an NMOSFET in which a gate, a source, and a back gate are short-circuited, which is simpler than a bidirectional Zener diode and easy to mount on an integrated circuit, is mounted instead of the bidirectional Zener diode. The circuit can be further simplified. As a result, the device can be prevented from being damaged by a high voltage of the inrush current at the time of ESD and switching on with a simple configuration.

It is the schematic which shows an example of the power window apparatus using the motor control apparatus which concerns on embodiment of this invention. It is a circuit diagram which shows an example of the motor control apparatus which concerns on embodiment of this invention. It is the schematic of the voltage dividing circuit comprised between the input stage and P / W switch of the motor control apparatus which concerns on this Embodiment. It is a figure which shows an example of the modification of this Embodiment which replaced with bidirectional Zener diode and mounted GGNMOSFET. 3 is a diagram illustrating an example of a circuit of a motor control device in which an ESD countermeasure capacitor is provided between a microcomputer and a P / W switch 14; FIG.

  FIG. 1 is a schematic diagram showing an example of a power window device 20 using a motor control device 10 according to the present embodiment. The power window device 20 is provided on the vehicle door 12 and includes a motor control device 10, a P / W switch 14, a power window motor 30, an elevating mechanism 40, and a window glass 54. Yes.

  The P / W switch 14 is a switch provided on the indoor side of the vehicle door 12, and inputs a command based on an operation for raising or lowering the window glass 54 to the motor control device 10. The motor control device 10 is a control device that controls the rotation of the power window motor 30 based on a command from the P / W switch 14 or the like. The power window motor 30 is decelerated with a motor main body 32 that is a brushed DC motor, for example. A mechanism 34 and an output shaft 36 are included. The motor body 32 may be a DC brushless motor in addition to the brushed DC motor.

  The speed reduction mechanism 34 is mainly composed of a worm gear, and reduces the rotational speed of the motor body 32 to a rotational speed suitable for raising and lowering the window glass 54 and increases the torque of the output shaft 36.

  A pinion gear 38A is attached to the output shaft 36, and a rack rail 38B provided at one end of a link arm 44A of the lifting mechanism is fitted to the pinion gear 38A. The rotation of the output shaft 36 is transmitted to the link arm 44A via the pinion gear 38A and the rack rail 38B.

  The link arm 44A has an upper pivot 50A fitted to a groove portion 50B provided in a window glass support portion 56 that is a metal member that reinforces the lower portion of the window glass 54 at the other end, and the upper pivot 50A is connected to the groove portion 50B. And is slidably attached.

  The elevating mechanism 40 includes a lower pivot 46A at one end and an upper pivot 48A at the other end, and has a link arm 44B that intersects the link arm 44A at a central pivot 42. The link arm 44A and the link arm 44B are attached so as to be rotatable with respect to each other by a central pivot 42.

  The lower pivot 46A of the link arm 44B is fitted into the groove 46B provided in the vehicle door 12, and the upper pivot 48A of the link arm 44B is fitted into the groove 48B provided in the window glass support 56, respectively. The upper pivot 48A is slidably attached to the groove 46B and the groove 48B.

  In the power window device 20 according to the present embodiment, when the output shaft 36 of the power window motor 30 rotates, the rotational force of the output shaft 36 is transmitted to the link arm 44A via the pinion gear 38A and the rack rail 38B. 44A causes the transmitted force to act on the groove 50B of the window glass support 56 with the center pivot 42 as a lever and the upper pivot 50A as a lever.

  Further, the link arm 44B moves along with the movement of the link arm 44A via the central pivot 42, and applies a force based on the rotational force of the output shaft 36 to the groove 48B of the window glass support 56, and as a result, the window The glass 54 moves up and down.

  FIG. 2 is a circuit diagram showing an example of the motor control device according to the embodiment of the present invention. The motor control apparatus 10 according to the present embodiment includes an MCU (Micro Controller) that outputs a command for controlling the rotation of the power window motor 30 to the relay 62 in accordance with commands input from the P / W switch 14 and the body ECU 16. Unit) 60 and a relay 62 that turns on or off the power supplied to the power window motor 30 based on a command from the MCU 60. In addition, an actual rotation speed of the power window motor 30 is fed back to the MCU 60 by inputting a signal related to the rotation speed of the power window motor 30 detected by the Hall IC 66.

  As an example, the P / W switch 14 includes an UP switch 14A for raising the window glass of the vehicle and a DOWN switch 14B for lowering the window glass of the vehicle. As an example, the UP switch 14A and the DOWN switch 14B are respectively connected to the UP input port 18A and the DOWN input port 18B of the MCU 60 via a resistance R1A and a resistance R1B of 75 kΩ.

  Further, the body ECU 16 provided on the vehicle side and controlling the in-vehicle devices including the power window device 20 outputs a command related to the control of the power window device 20 to the MCU 60 in accordance with the LIN communication control. The command output by the body ECU 16 is different from a signal generated by operating the P / W switch 14 such as closing the window glass 54 when the vehicle engine is stopped.

  The body ECU 16 is connected to the LIN input port 18 </ b> C of the MCU 60 through the choke coil 94. Further, an anode of a Zener diode 96A is connected between the choke coil 94 and the MCU 60. The cathode of the Zener diode 96 </ b> A is connected to the cathode of a Zener diode 96 </ b> B whose anode is grounded to constitute a so-called bidirectional Zener diode 96. In the present embodiment, the high voltage generated between the body ECU 16 and the MCU 60 is grounded via the bidirectional Zener diode 96, thereby preventing damage to circuits such as the MCU 60.

  The MCU 60 is connected to the input stage 80 to which a signal is input from the P / W switch 14 via the UP input port 18A and the DOWN input port 18B, and the body ECU 16 via the LIN input port 18C, and is connected to the LIN communication control. LIN driver 74 for performing The input stage 80 and the LIN driver 74 are each connected to the microcomputer 70.

  The microcomputer 70 receives a control voltage from the 5V regulator 72 and controls the relay 62 to the relay driver 64 based on signals input from the UP input port 18A, the DOWN input port 18B, and the LIN input port 18C. Control command for output. A signal related to the rotational speed of the power window motor 30 detected by the Hall IC 66 is input to the microcomputer 70 via a dark current reduction circuit 68 that reduces the dark current included in the signal.

  As shown in FIG. 2, the MCU 60 included in the motor control apparatus 10 according to the present embodiment includes a microcomputer 70, a 5V regulator 72, a relay driver 64, a dark current reduction circuit 68, an input stage 80, a LIN driver 74, and the like. One integrated circuit. By consolidating the configuration of the microcomputer 70 and the like into one integrated circuit, the circuit of the motor control device 10 can be simplified, and the manufacturing cost of the motor control device 10 can be reduced. Further, unlike the example shown in FIG. 5, since an element such as a capacitor for preventing ESD is not mounted on the circuit, the electrical energy in the capacitor is discharged when the switch is turned on, and the circuit element and the switch Can be prevented from being damaged.

  The input stage 80 includes a comparator 88A and a comparator 88B. The comparator 88A converts an analog signal from the UP input port 18A into a digital signal, and the comparator 88B converts the analog signal from the DOWN input port 18B into a digital signal. Output. As an example, the input ends of the comparator 88A and the comparator 88B are connected to the UP input port 18A and the DOWN input port 18B of the MCU 60 through a 372 kΩ resistor R2A and a resistor R2B, respectively.

  A clamp circuit 86A having one end grounded is connected to the input end of the comparator 88A. A clamp circuit 86B having one end grounded is connected to the input end of the comparator 88B. The clamp circuit 86A and the clamp circuit 86B suppress the voltage applied to the input terminals of the comparator 88A and the comparator 88B to, for example, 10 V or less.

  A cathode of a Zener diode 82A is connected between the UP input port 18A and the resistor R2A. The anode of the Zener diode 82A is connected to the anode of a Zener diode 84A whose cathode is grounded to constitute a so-called bidirectional Zener diode 90.

  The cathode of the Zener diode 82B is connected between the DOWN input port 18B and the resistor R2B. The anode of the Zener diode 82B is connected to the anode of a Zener diode 84B whose cathode is grounded to constitute a so-called bidirectional Zener diode 92. The breakdown voltages of the Zener diodes 82A, 82B, 84A, 84B are each 45V, for example.

  For example, when a voltage higher than the breakdown voltage is applied to the UP input port 18A by ESD, for example, the applied high voltage is applied from the cathode of the Zener diode 82A to the anode, and further from the anode of the Zener diode 84A to the GND through the cathode. Discharged. In addition, when a voltage higher than the breakdown voltage is applied to the DOWN input port 18B, the applied high voltage is applied to the GND from the cathode of the Zener diode 82B to the anode, and further from the anode to the cathode of the Zener diode 84B. Discharged. Due to the discharge through the bidirectional Zener diode, the input stage 80 is a high voltage circuit.

  The anodes of the Zener diodes 82A and 82B are connected between the UP input ports 18A and 18B and the resistors R2A and R2B, respectively. The cathodes of the Zener diodes 82A and 82B are connected to the cathodes of the Zener diodes 84A and 84B, respectively. Also good. In such a case, the anodes of the Zener diodes 84A and 84B are grounded.

  In addition, the resistor R1A, the resistor R2A, and the Zener diodes 82A and 84A, and the resistor R1B, the resistor R2B, and the Zener diodes 82B and 84B each form a kind of voltage dividing circuit. FIG. 3 is a schematic diagram of a voltage dividing circuit configured between the input stage 80 and the P / W switch 14 of the motor control device 10 according to the present embodiment.

As an example, the resistors R1A and R1B are 75 kΩ each, and the resistors R2A and R2B are 372 kΩ each. In such a case, the Zener diodes 82A and 84A and the Zener diodes 82B and 84B are respectively divided by 83% of the voltage applied from the P / W switch 14 side as shown in the following formula (1). The voltage applied to the comparators 88A and 88B can be reduced by the voltage division and the discharge to the GND by the bidirectional Zener diodes 90 and 92. As a result, it is possible to increase the breakdown voltage of the MCU 60 including the comparators 88A and 88B and the microcomputer 70 which are configured by CMOS (Complementary MOS).

  In order to greatly divide the applied voltage to the bidirectional Zener diodes 90 and 92 as calculated by the equation (1), the resistors R2A and R2B provided closer to the comparators 88A and 88B than the resistors R1A and R1B are used. The resistance value is made larger than the resistance values of the resistors R1A and R1B. However, if the voltage is excessively divided into the bidirectional Zener diodes 90 and 92, the signal to be output to the comparators 88A and 88B may be damaged. The resistance values of the resistors R1A and R1B and the resistors R2A and R2B are determined to be appropriate values through circuit design simulation and trial manufacture. 2 and 4, the resistors R1A and R1B are not mounted in the MCU 60, but may be mounted in the MCU 60 together with the bidirectional Zener diodes 90 and 92 and the resistors R2A and R2B.

  In this embodiment, a GGNMOSFET (Gate Grounded NMOS FET), which is an NMOSFET in which the gate, the source, and the back gate are short-circuited, may be mounted instead of the bidirectional Zener diode.

  FIG. 4 is a diagram showing an example of a modification of the present embodiment in which the GGNMOSFET 98 is mounted. As shown in FIG. 4, the GGNMOSFET 98 is provided between the UP input port 18A and the resistor R2A, and between the DOWN input port 18B and the resistor R2B, instead of the bidirectional Zener diodes 90 and 92, respectively. ing.

  When a high voltage is applied to the UP input port 18A or the DOWN input port 18B due to an inrush current at the time of ESD and switching on, the GGNMOSFET 98 is applied in the same manner as the bidirectional Zener diodes 90 and 92. Discharge the voltage to GND.

  Further, the GGNMOSFET shown in FIG. 4 has a simple configuration and has an advantage that an area required for mounting on the integrated circuit is smaller than that of the bidirectional Zener diode. Therefore, when a bidirectional Zener diode is mounted on the MCU 60 as one integrated circuit together with the microcomputer 70 and other elements, it is effective to mount a GGNMOSFET instead of the bidirectional Zener diode as in this modification. is there.

  As described above, according to the present embodiment, damage to the elements due to the high voltage of the inrush current at the time of ESD and switching on is achieved with a simple configuration in which elements such as capacitors for preventing ESD are not mounted on the circuit. Can prevent

DESCRIPTION OF SYMBOLS 10 ... Motor control device, 12 ... Vehicle door, 14 ... P / W switch, 14A ... UP switch, 14B ... DOWN switch, 16 ... Body ECU, 18A ..UP input port, 18B ... DOWN input port, 18C ... LIN input port, 20 ... power window device, 30 ... power window motor, 32 ... motor body, 34. ..Deceleration mechanism 36 ... Output shaft 38A ... Pinion gear 38B ... Rack rail 40 ... Elevating mechanism 42 ... Center pivot 44A ... Link arm 44B Link arm, 46A ... lower pivot, 48A ... upper pivot, 48B ... groove, 50A ... upper pivot, 50B ... groove, 54 ... window glass, 56 ..Window glass support part, 60... MCU, 62... Relay, 64... Relay driver, 66 .. Hall IC, 68 .. dark current reduction circuit, 70. .. 5V regulator, 74 ... LIN driver, 80 ... input stage, 82A, 82B, 84A, 84B ... Zener diode, 86A, 86B ... clamp circuit, 88A, 88B ... comparator, 90 , 92... Bidirectional Zener diode, 94... Choke coil, 96... Bidirectional Zener diode, 96 A, 96 B... Zener diode, 98. ... UP input port, 118B ... DOWN input port, 118C ... LIN input port, 130 ... 162, relay, 164, relay driver, 168, dark current reduction circuit, 172, 5V regulator, 174, LIN driver, 192A, 192B, ESD protection capacitor, 194 ..Choke coils, R1A, R1B, R2A, R2B ... resistance

Claims (3)

Control means for controlling the rotation of the motor based on the operation of the switch;
A signal conversion unit provided between the control unit and the switch, which converts an analog signal input from the switch into a digital signal and inputs the digital signal;
A bidirectional Zener diode having one end connected between the switch and the signal converting means and the other end grounded, and discharging to the ground side when the voltage of the analog signal becomes a breakdown voltage or higher, and one end A clamp circuit which is connected between one end of the bidirectional Zener diode and the signal conversion unit and whose other end is grounded, and which suppresses the voltage of the analog signal input to the signal conversion unit to a predetermined voltage or less; High voltage circuit,
A motor control device comprising one integrated circuit including A first resistor provided between the switch and the bidirectional Zener diode of the high withstand voltage circuit;
2. The motor control device according to claim 1 , wherein the high breakdown voltage circuit further includes a second resistor having a resistance value larger than that of the first resistor between the bidirectional Zener diode and the clamp circuit . Instead of the bidirectional Zener diode, gate, shorted source and a back gate, the drain is connected between the signal converting means and said switch, according to claim 1 or source having a NMOSFET grounded 2. The motor control device according to 2.