JP2020062910A - Vehicular motor device - Google Patents

Abstract

To suppress power consumption by a motor while suppressing an occupant in a vehicle from listening to audible sound.SOLUTION: A driver 56B includes: a transistor Tr1 that can open and close a space between one end of winding of a wiper motor 18 and a positive electrode of a battery 80; a transistor Tr2 that can open and close a space between the other end of the winding of the wiper motor 18 and the positive electrode of the battery 80; a transistor Tr3 that can open and close a space between the one end of the winding of the wiper motor 18 and a negative electrode of the battery 80; and a transistor Tr4 that can open and close a space between the other end of the winding of the wiper motor 18 and the negative electrode of the battery 80. A wiper ECU 58 and a pre-driver 56A supply PWM signals for driving the wiper motor 18 by PWM to the transistors of the driver 56B and control frequencies of the PWM signals according to sound volumes in a vehicle interior of a vehicle.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle motor device.

  In Patent Document 1, an H bridge circuit is formed by four field effect transistors, and a PWM (Pulse Width Modulation) signal is supplied to each transistor to control the rotation direction and rotation speed of the wiper motor. The configuration is described.

Patent No. 6294138

  When a vehicle-mounted motor such as a wiper motor is driven by PWM, the motor (coil) vibrates at the frequency of the PWM signal as the transistor turns on and off. Therefore, in order to suppress the vibration of the motor (coil) from being heard as an audible sound by the occupant of the vehicle and giving the passenger an uncomfortable feeling, the frequency of the PWM signal is higher than the audible range (for example, 20 [ kHz]) is set.

  However, when the in-vehicle motor is driven by the H-bridge circuit, it is necessary to provide a dead time in order to prevent a through current that does not pass through the in-vehicle motor from flowing. Then, as the frequency of the PWM signal increases, the time ratio of the dead time occupied in the PWM signal increases, and the driving efficiency of the motor decreases. Therefore, set the frequency of the PWM signal to a higher frequency side than the audible range. Had a problem of increasing the power consumption of the motor.

  The present invention has been made in consideration of the above facts, and an object of the present invention is to obtain a vehicle motor device capable of suppressing power consumption of a motor while suppressing audible sound from being heard by a vehicle occupant. Is.

  A vehicle motor device according to a first aspect of the present invention is a motor mounted on a vehicle, a first switching element capable of opening and closing between one end of a winding of the motor and a power supply end, winding of the motor. A second switching element capable of opening / closing between the other end of the motor and the feeding end, a third switching element capable of opening / closing between one end of the winding of the motor and a ground end, and another winding of the motor A drive unit including a fourth switching element that can be opened and closed between an end and the grounded end, and a PWM signal for driving the motor by PWM are supplied to each switching element of the drive unit, and the PWM signal A control unit that controls the frequency according to the volume of the vehicle interior of the vehicle.

  According to a first aspect of the present invention, a first switching element, a second switching element, a third switching element, and a fourth switching element of a drive unit form an H bridge circuit, and a PWM for driving a motor by PWM. A signal is supplied to each switching element. Here, based on the fact that various sounds are heard in the vehicle interior of the vehicle, in the first aspect of the present invention, the frequency of the PWM signal is controlled according to the volume in the vehicle interior of the vehicle.

  As a result, when the vibration of the motor (winding) due to the switching on / off of the switching element is in a volume state in which it is difficult for the occupant of the vehicle to hear as audible sound, the time ratio of the dead time in the PWM signal is reduced. It becomes possible to control the frequency of the PWM signal so that the driving efficiency of the motor can be reduced by improving the frequency. Therefore, according to the first aspect of the present invention, it is possible to suppress power consumption of the motor while suppressing audible sound from being heard by a vehicle occupant.

  According to a second aspect of the present invention, in the first aspect of the present invention, the control unit controls the volume of the vehicle interior is less than a predetermined value when the volume of the vehicle interior is a predetermined value or more. Also lowers the frequency of the PWM signal.

  As a result, when the vibration of the motor due to the turning on / off of the switching element is in a volume state where it is difficult for the occupant of the vehicle to hear as an audible sound, the frequency of the PWM signal is lowered to reduce the time ratio of the dead time in the PWM signal. The size can be reduced to improve the driving efficiency of the motor.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the control unit is configured to: when the vehicle speed detected by a vehicle speed detection unit that detects the speed of the vehicle is equal to or higher than a predetermined value. The frequency of the PWM signal is set lower than when the vehicle speed is less than a predetermined value.

  According to the third aspect of the present invention, based on the vehicle speed detected by the vehicle speed detecting unit, indirectly estimates a volume situation in which the vibration of the motor due to the turning on / off of the switching element is difficult to be heard as an audible sound by a vehicle occupant. There is. As a result, it is not necessary to separately provide a means for detecting the volume inside the vehicle, and the number of parts of the device can be reduced.

  A fourth aspect of the present invention is the air conditioner according to any one of the first to third aspects of the present invention, wherein the control unit is a first detection unit that detects ON / OFF of an air conditioner mounted on the vehicle. When ON is detected, the frequency of the PWM signal is made lower than when OFF of the air conditioner is detected.

  According to the fourth aspect of the present invention, based on the on / off state of the air conditioner mounted on the vehicle, the volume situation in which the vibration of the motor accompanying the on / off state of the switching element is hard to be heard as an audible sound by the vehicle occupant is indirectly estimated. ing. As a result, it is not necessary to separately provide a means for detecting the volume inside the vehicle, and the number of parts of the device can be reduced.

  A fifth aspect of the present invention is the device according to any one of the first to fourth aspects of the present invention, wherein the control unit controls the amount of air flow by a second detection unit that detects an amount of air flow by an air conditioner mounted on the vehicle. When it is detected that the air volume is equal to or more than the predetermined value, the frequency of the PWM signal is made lower than that when the air volume is less than the predetermined value.

  According to the fifth aspect of the present invention, based on the air volume of the air conditioner mounted on the vehicle, the vibration of the motor due to the on / off of the switching element is indirectly estimated as a audible sound to the occupants of the vehicle. ing. As a result, it is not necessary to separately provide a means for detecting the volume inside the vehicle, and the number of parts of the device can be reduced.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, the control unit is set by a wiper switch that sets a wiping speed by a wiper device mounted on the vehicle. When the wiping speed is equal to or higher than the predetermined value, the frequency of the PWM signal is lower than when the wiping speed is lower than the predetermined value.

  In the sixth aspect of the present invention, based on the wiping speed of the wiper device mounted on the vehicle, indirectly estimates the volume situation in which the vibration of the motor due to the turning on / off of the switching element is difficult to be heard as an audible sound by the occupants of the vehicle. is doing. As a result, it is not necessary to separately provide a means for detecting the volume inside the vehicle, and the number of parts of the device can be reduced.

  In a seventh aspect of the present invention according to any one of the first to sixth aspects of the present invention, the control unit controls the rain amount to be a predetermined value when the rain amount detected by the rain amount detection unit is a predetermined value or more. The frequency of the PWM signal is made lower than that in the case of less than.

  In the seventh aspect of the present invention, the volume situation in which the vibration of the motor due to the turning on / off of the switching element is difficult to be heard as an audible sound by the occupants of the vehicle is indirectly estimated based on the rainfall amount. As a result, it is not necessary to separately provide a means for detecting the volume inside the vehicle, and the number of parts of the device can be reduced.

  An eighth aspect of the present invention is the audio device according to any one of the first to seventh aspects of the present invention, wherein the control section uses a third detection section that detects whether the audio apparatus mounted in the vehicle is on or off. Is detected, the frequency of the PWM signal is made lower than that when the audio device is detected to be off.

  According to the eighth aspect of the present invention, based on the on / off state of the audio device mounted on the vehicle, the volume situation in which the vibration of the motor accompanying the on / off state of the switching element is hard to be heard as an audible sound by the vehicle occupant is indirectly estimated. ing. As a result, it is not necessary to separately provide a means for detecting the volume inside the vehicle, and the number of parts of the device can be reduced.

  According to a ninth aspect of the present invention, in any one of the first to eighth aspects of the present invention, the control unit controls the volume by the fourth detection unit that detects the volume by the audio device mounted on the vehicle. When it is detected that the volume is equal to or higher than the predetermined value, the frequency of the PWM signal is set lower than when the volume is lower than the predetermined value.

  According to a ninth aspect of the present invention, based on the volume of an audio device mounted on a vehicle, the volume situation in which the vibration of the motor accompanying the switching on / off of the switching element is hard to be heard as an audible sound by an occupant of the vehicle is indirectly estimated. ing. As a result, it is not necessary to separately provide a means for detecting the volume inside the vehicle, and the number of parts of the device can be reduced.

  According to a tenth aspect of the present invention, in any one of the first to ninth aspects of the present invention, the vehicle is equipped with an engine, and the engine is selectively driven while an ignition switch is on. The control unit lowers the frequency of the PWM signal when the engine is being driven, as compared with when the driving of the engine is stopped.

  In the tenth aspect of the present invention, based on the driving state of the engine mounted on the vehicle, the volume situation in which the vibration of the motor due to the turning on / off of the switching element is hard to be heard as audible sound by the vehicle occupant is indirectly estimated. ing. As a result, it is not necessary to separately provide a means for detecting the volume inside the vehicle, and the number of parts of the device can be reduced.

  An eleventh aspect of the present invention is the wiper motor according to any one of the first to tenth aspects of the present invention.

  The wiper motor is disposed near the vehicle compartment of the vehicle, and the vibration of the motor due to the switching elements being turned on and off is easily perceived as an audible sound by an occupant of the vehicle, which is suitable for the present invention.

It is a schematic diagram showing composition of a wiper device concerning a 1st embodiment. It is a block diagram showing composition of a wiper control device concerning an embodiment. 6 is a flowchart showing a wiper drive control process according to the first embodiment. 6 is a timing chart showing an example of a PWM signal at low volume and high volume. 6 is a timing chart showing an example of switching the frequency of the PWM signal with respect to a change in vehicle speed. It is a schematic diagram showing composition of a wiper device concerning a 2nd embodiment and a 3rd embodiment. It is a flow chart which shows wiper drive control processing concerning a 2nd embodiment. It is a flow chart which shows wiper drive control processing concerning a 3rd embodiment. It is a diagram showing an example of a map of the volume evaluation value.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
As shown in FIG. 1, a wiper device 100 according to an embodiment is a device for wiping a windshield glass 12 provided in a vehicle such as a passenger car, and includes a pair of wipers 14, 16, a wiper motor 18, a link mechanism 20, and A wiper control device 10 is included. In this embodiment, the wiper motor 18 is a brushed DC motor. The wiper motor 18 is an example of a motor.

  The wiper 14 includes a wiper arm 24 having a base end fixed to the pivot shaft 42, and a wiper blade 28 connected to a tip end of the wiper arm 24. The wiper 16 has a base end attached to the pivot shaft 44. It includes a wiper arm 26 connected to the wiper arm 26 and a wiper blade 30 fixed to the tip of the wiper arm 26. In the wipers 14 and 16, when the wiper arms 24 and 26 are rotated about the pivot shafts 42 and 44, the wiper blades 28 and 30 reciprocate on the windshield glass 12, and the wiper blades 28 and 30 are windshield glass. Wipe off 12.

  The wiper motor 18 has an output shaft 32 that is decelerated by a deceleration mechanism 52 mainly composed of a worm gear and is normally and reversely rotated in a predetermined rotation angle range θ1. The link mechanism 20 includes a crank arm 34, a first link rod 36, a pair of pivot levers 38 and 40, a pair of pivot shafts 42 and 44, and a second link rod 46.

  One end of the crank arm 34 is fixed to the output shaft 32 of the wiper motor 18, and the other end of the crank arm 34 is rotatably connected to one end of the first link rod 36. The other end of the first link rod 36 is rotatably connected to an intermediate portion of the pivot lever 38. One end of the second link rod 46 is rotatably connected to an end of the pivot lever 38 opposite to the end fixed to the pivot shaft 42, and the other end thereof is pivotally connected to the pivot lever 40. Of the two, it is rotatably connected to an end opposite to the end fixed to the pivot shaft.

  Further, the pivot shafts 42 and 44 are rotatably supported by a pivot holder (not shown) provided on the vehicle body, and the end portions of the pivot levers 38 and 40 on the side fixed to the pivot shafts 42 and 44 are The wiper arms 24 and 26 are connected via pivot shafts 42 and 44, respectively.

  In the wiper device 100, the output shaft 32 of the wiper motor 18 is normally and reversely rotated within a predetermined rotation angle range θ1, and the rotational force of the output shaft 32 is transmitted to the wiper arms 24 and 26 via the link mechanism 20. The wiper blades 28 and 30 reciprocate between the lower reversal position P2 and the upper reversal position P1 on the windshield glass 12 in accordance with the reciprocating rotation of the. The rotation angle range θ1 can take various values depending on the configuration of the link mechanism of the wiper device 100 and the like, but as an example, θ1 = 140 °.

  A storage position P3 is provided below the lower reversal position P2. When the output shaft 32 rotates by the rotation angle θ2 from the state where the wiper blades 28, 30 are in the lower reversal position P2, the wiper blades 28, 30 move to the storage position P3. The rotation angle θ2 can take various values depending on the configuration of the link mechanism of the wiper device 100 and the like, but as an example, θ2 = 10 °. When the rotation angle θ2 = 0 °, the lower reversal position P2 coincides with the storage position P3, and the wiper blades 28 and 30 are stopped and stored at the lower reversal position P2. When the rotation angle θ2 = 0 °, for example, the rotation angle θ1 = 150 ° may be set so that the lower reversal position P and the storage position P3 coincide with each other.

  On the other hand, the wiper control device 10 includes a wiper control unit 22 for controlling the rotation of the wiper motor 18, and the wiper control unit 22 is connected to the wiper motor 18. The wiper control unit 22 includes a wiper ECU (Electronic Control Unit) 58, a drive circuit 56, and a rotation angle sensor 54.

  The wiper ECU 58 includes a CPU 58A, a memory 58B, and a non-volatile storage unit 58C. The wiper ECU 58 rotates the position of the wiper blades 28, 30 on the windshield glass 12 and the rotation of the output shaft 32 based on the detection result of the rotation angle sensor 54 that detects the rotation speed and the rotation angle of the output shaft 32 of the wiper motor 18. The speed is calculated, and the drive circuit 56 is controlled so that the rotation speed of the output shaft 32 changes according to the calculated position. The rotation angle sensor 54 is provided in the speed reduction mechanism 52 of the wiper motor 18, and detects the magnetic field (magnetic force) of the sensor magnet that rotates in conjunction with the output shaft 32 by converting it into a current.

  In the present embodiment, since the output shaft 32 of the wiper motor 18 is decelerated by the speed reduction mechanism 52, the rotation speed and the rotation angle of the output shaft 32 are not the same as the rotation speed and the rotation angle of the wiper motor body. However, in the present embodiment, since the wiper motor main body and the speed reduction mechanism 52 are inseparably integrated, the rotation speed and the rotation angle of the output shaft 32 will be regarded as the rotation speed and the rotation angle of the wiper motor 18 hereinafter. The data related to the control of the drive circuit 56 is stored in the storage unit 58C in advance.

  A wiper switch 50 and a vehicle speed sensor 51 are connected to the wiper ECU 58 of the wiper controller 22 via a main ECU 92 that controls the engine of the vehicle. The wiper switch 50 is a switch that turns on or off the electric power supplied from the battery 80 of the vehicle to the wiper motor 18. The wiper switch 50 includes a low speed operation position (LOW) for operating the wiper blades 28 and 30 at a low speed, a high speed operation position (HIGH) for operating the high speed, an intermittent operation position (INT) for intermittently operating the wiper blades 28 at a constant cycle, and a stop. The contact can be switched to the position (OFF). The main ECU 92 detects the contact position of the wiper switch 50, and outputs the detection result as a command signal to the wiper ECU 58 via the signal input circuit 62 (FIG. 2). The vehicle speed sensor 51 detects the vehicle speed V, and the vehicle speed V detected by the vehicle speed sensor 51 is output to the wiper ECU 58 via the main ECU 92.

  The wiper ECU 58 rotates the output shaft 32 of the wiper motor 18 at high speed when the contact position of the wiper switch 50 input as a command signal is at a high speed operation position, and the contact position of the wiper switch 50 input as a command signal is at a low speed. In the operating position, the output shaft 32 of the wiper motor 18 is rotated at a low speed. When the contact position of the wiper switch 50 input as the command signal is the intermittent operation position, the wiper ECU 58 reciprocally wipes the wiper blades 28 and 30 between the upper reversal position P1 and the lower reversal position P2, and The wiper motor 18 is intermittently rotated so as to stop at the reverse position P2 for a predetermined time. The wiper switch 50 may have an automatic operating position (AUTO) that changes the rotation speed of the output shaft 32 of the wiper motor 18 in accordance with the amount of rain detected by a rain sensor or an in-vehicle camera.

  As shown in FIG. 2, the wiper ECU 58 is supplied with the electric power of the battery 80 via the diode 68, and the voltage of the electric power supplied from the battery 80 is provided between the diode 68 and the wiper ECU 58. It is detected by the voltage detection circuit 60, and the detection result is output to the wiper ECU 58.

  Further, one end (+ terminal) of the electrolytic capacitor C1 is connected between the diode 68 and the wiper ECU 58, and the other end (− terminal) of the electrolytic capacitor C1 is grounded. The electrolytic capacitor C1 is a capacitor for stabilizing the power supply of the wiper ECU 58. The electrolytic capacitor C1 protects the wiper ECU 58 by storing a sudden high voltage such as a surge and discharging it to a ground area.

  The wiper ECU 58 is also connected to a rotation angle sensor 54 that detects a magnetic field of the sensor magnet 70 that changes according to the rotation of the output shaft 32. The wiper ECU 58 detects the position of the wiper blades 28, 30 on the windshield glass 12 by calculating the rotation angle of the output shaft 32 based on the signal output by the rotation angle sensor 54.

  Further, the wiper ECU 58 refers to the data of the rotation speed of the wiper motor 18 which is stored in advance in the storage unit 58C and is defined according to the positions of the wiper blades 28 and 30, and the rotation of the wiper motor 18 is determined by the identified wiper blade. The drive circuit 56 is controlled so that the number of rotations corresponds to the positions of 28 and 30.

  The drive circuit 56, based on the control signal input from the wiper ECU 58, generates a PWM signal for turning on / off the transistor of the driver 56B at a frequency and a duty ratio designated by the control signal, a pre-driver 56A, and four transistors Tr1, In accordance with the PWM signal output from the pre-driver 56A including Tr2, Tr3 and Tr4, the transistors Tr1, Tr2, Tr3 and Tr4 are turned on / off (the driving circuit 56 is opened / closed by the transistors Tr1, Tr2, Tr3 and Tr4) to cause the coil of the wiper motor 18 to operate. And a driver 56B for energizing.

  The driver 56B is an example of a drive unit, and the wiper ECU 58 and the pre-driver 56A are an example of a control unit. The transistor Tr1 is an example of a first switching element, the transistor Tr2 is an example of a second switching element, the transistor Tr3 is an example of a third switching element, and the transistor Tr4 is an example of a fourth switching element.

The gates of the transistors Tr1, Tr2, Tr3, Tr4 of the driver 56B are connected to the pre-driver 56A, respectively. The drains of the transistors Tr1 and Tr2 are connected to the positive electrode of the battery 80 via the noise prevention coil 66, the source of the transistor Tr1 is connected to the drain of the transistor Tr3, and the source of the transistor Tr2 is connected to the drain of the transistor Tr4. There is. The sources of the transistors Tr3 and Tr4 are grounded. The source of the transistor Tr1 and the drain of the transistor Tr3 are connected to one end of the winding of the wiper motor 18, and the source of the transistor Tr2 and the drain of the transistor Tr4 are connected to the other end of the winding of the wiper motor 18. . In this way, the transistors Tr1, Tr2, Tr3, Tr4 of the driver 56B form an H bridge circuit. When the transistor Tr1 is turned on (closed), a current flows from the positive electrode of the battery 80 to one end of the winding. When the transistor Tr1 is turned off (opened), no current flows from the positive electrode of the battery 80 to one end of the winding.

  For example, when the wipers 14 and 16 are operated in the forward path, the pre-driver 56A constantly turns on the transistor Tr1, turns on and off the transistor Tr4 at a predetermined duty ratio, and turns the transistor Tr2 on and off, as shown in FIG. Is supplied to the driver 56B to turn it on when is off. However, if the transistors Tr2 and Tr4 are turned on at the same time, a through current that short-circuits the positive electrode and the negative electrode of the battery 80 without passing through the wiper motor 18 flows, causing a failure of the wiper device 100 or the like. Therefore, the PWM signal has a dead time (a time for turning on the transistor Tr1 and turning off both the transistors Tr2 and Tr4) in order to prevent a shoot-through current, as shown by a dashed line in FIG. 4, for example. It is provided. The PWM signal causes the wiper motor 18 to pass, for example, a motor current in a direction in which the wipers 14 and 16 are operated in the forward direction (the motor current flows so as to rotate the output shaft 32 of the wiper motor 18 forward).

  Further, for example, when the wipers 14 and 16 are operated in the return path, the pre-driver 56A constantly turns on the transistor Tr2, turns on and off the transistor Tr3 in small increments at a predetermined duty ratio, and turns on the transistor Tr1 when the transistor Tr3 is off. The PWM signal is supplied to the driver 56B. However, if the transistors Tr1 and Tr3 are turned on at the same time, a through current that short-circuits the positive electrode and the negative electrode of the battery 80 without passing through the wiper motor 18 flows, causing a failure of the wiper device 100 and the like. Therefore, the PWM signal is also provided with a dead time (time to turn on the transistor Tr2 and turn off both the transistors Tr1 and Tr3) in order to prevent a shoot-through current. Due to the PWM signal described above, a motor current flows in the wiper motor 18 in a direction in which the wipers 14 and 16 are operated to return (for example, a motor current flows so as to rotate the output shaft 32 of the wiper motor 18 forward).

  A reverse connection protection circuit 64 and a noise prevention coil 66 are provided between the battery 80, which is a power source, and the drive circuit 56, and an electrolytic capacitor C2 is connected in parallel to the drive circuit 56. The noise prevention coil 66 suppresses noise generated by the switching of the drive circuit 56. The electrolytic capacitor C2 alleviates noise generated from the drive circuit 56, stores a sudden high voltage such as a surge, and discharges it to the ground region to prevent an excessive current from being input to the drive circuit 56.

  The reverse connection protection circuit 64 is a circuit for protecting each element of the wiper control device 10 when the positive electrode and the negative electrode of the battery 80 are connected in the opposite manner to that of FIG. The reverse connection protection circuit 64 is configured by, for example, a so-called diode-connected FET in which its drain and gate are connected to each other.

  A chip thermistor RT that detects the temperature of the substrate as a resistance value is provided on the substrate of the wiper control device 10. The chip thermistor RT constitutes a kind of voltage dividing circuit, and a voltage that changes based on the resistance value of the chip thermistor RT is output from the output terminal of the voltage dividing circuit formed by the chip thermistor RT. The wiper ECU 58 calculates the temperature of the substrate of the wiper control device 10 based on the voltage output from the output terminal of the voltage dividing circuit formed by the chip thermistor RT, and when the temperature exceeds a predetermined threshold temperature, wiper control is performed. The operation of the device 10 is stopped.

  Further, a current detector 82 for detecting a current (motor current) between the coil of the wiper motor 18 and the driver 56B is provided between the sources of the transistors Tr3 and Tr4 included in the driver 56B and the battery 80. . The current detection unit 82 detects a potential difference between both ends of the shunt resistor 82A having a resistance value of about 0.2 mΩ to several Ω and the shunt resistor 82A that changes according to the current of the driver 56B, and amplifies the detected potential difference signal. The amplifier 82B is included. The wiper ECU 58 calculates the current value of the motor current from the signal output by the amplifier 82B.

  Next, as an operation of the first embodiment, a wiper drive control process according to the first embodiment will be described with reference to FIG. In step 100, the wiper ECU 58 drives the wiper motor 18 to drive the wiper motors 14 and 16 based on whether the wiper switch 50 is in the low speed operation position (LOW), the high speed operation position (HIGH) or the intermittent operation position (INT). It is determined whether or not the windshield glass 12 is wiped back and forth. When the wiper switch 50 is in the stop position (OFF), the determination at step 100 is denied and the determination at step 100 is repeated.

  When the wiper switch 50 is in the low speed operation position (LOW), the high speed operation position (HIGH) or the intermittent operation position (INT), the determination in step 100 is affirmative and the process proceeds to step 102. In step 102, the wiper ECU 58 determines whether the vehicle speed V detected by the vehicle speed sensor 51 is equal to or higher than a predetermined threshold value Vth. If the determination in step 102 is negative, for example, the volume of wind noise caused by traveling of the vehicle is relatively low, and therefore it can be estimated that the volume of the vehicle interior of the vehicle is relatively low (noise in the vehicle interior is low). Therefore, when the wiper motor 18 is driven, it can be determined that the vibration associated with the turning on / off of the transistors Tr1, Tr2, Tr3, Tr4 is easily heard as an audible sound by the vehicle occupant.

  Therefore, if the determination in step 102 is negative, the process proceeds to step 104, and in step 104, the wiper ECU 58 sets the frequency at the low volume as the frequency of the PWM signal. The frequency when the volume is low is set to a frequency at which vibrations associated with the on / off states of the transistors Tr1, Tr2, Tr3, and Tr4 are difficult to be heard as audible sound by vehicle occupants (an example is shown in FIG. 4A). Can be set to 20 [kHz]. As a result, it is possible to prevent the occupants of the vehicle from hearing vibrations associated with the on / off states of the transistors Tr1, Tr2, Tr3, Tr4 as audible sounds.

  If the determination in step 102 is affirmative, it can be estimated that, for example, the volume of wind noise caused by the traveling of the vehicle is relatively large, and the interior of the vehicle is relatively loud (the noise inside the vehicle is large). Therefore, even when the wiper motor 18 is driven, the vibrations caused by turning on / off the transistors Tr1, Tr2, Tr3, Tr4 are masked by other sounds even if the frequency of the vibrations is in the audible range, and the occupant of the vehicle is prevented from doing so. It can be judged that it is difficult to hear as audible sound.

  Therefore, when the determination in step 102 is affirmative, the process proceeds to step 106, and in step 106, the wiper ECU 58 sets the frequency at the loud volume as the frequency of the PWM signal. The frequency at high volume is set to a frequency at which the drive time of the wiper motor 18 can be improved and power consumption can be suppressed by reducing the time ratio of the dead time in the PWM signal. 4 (B)), for example, 10 [kHz] can be set. For example, if the frequency of the PWM signal is halved (20 [kHz] to 10 [kHz]), the frequency of occurrence of dead time in a predetermined time becomes 50%, and the drive efficiency of the wiper motor 18 is improved. Power consumption is suppressed.

  When the process of step 104 or step 106 is performed, the process proceeds to step 108. In step 108, the wiper ECU 58 drives the wiper motor 18 by the PWM signal of the frequency set in step 104 or step 106 to wipe the windshield glass 12 back and forth by the wipers 14 and 16, and then returns to step 100.

  As a result, as shown in FIG. 5 as an example, when the vehicle speed V is less than the predetermined threshold value Vth, the frequency of the PWM signal is set to the frequency when the volume is low, so that the transistors Tr1, Tr2, Tr3, It is possible to prevent the occupant of the vehicle from hearing the vibration associated with the turning on / off of Tr4 as an audible sound. Further, when the vehicle speed V becomes equal to or higher than the predetermined threshold value Vth, the frequency of the PWM signal is set to the frequency at the time of high volume, thereby improving the driving efficiency of the wiper motor 18 and suppressing the power consumption. be able to.

  The threshold value Vth of the vehicle speed V may be different when the vehicle speed V is increasing and when it is decreasing. For example, in a vehicle that uses an engine as a power source, when the vehicle speed V is increasing, the volume of the vehicle interior becomes a sound source as compared to when the vehicle speed V is decreasing. Since it is estimated to be larger, the threshold value Vth may be set to a smaller value (threshold value Vth when the vehicle speed V increases <threshold value Vth when the vehicle speed V decreases).

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

  In the second embodiment, the vehicle equipped with the wiper device 100 is a hybrid vehicle including an engine and a motor as power sources. Driving / stopping of the engine is controlled by the main ECU 92. The engine drive / drive stop state is detected by the engine drive state detection unit 84 shown in FIG. 6, and is notified from the main ECU 92 to the wiper ECU 58. Although the main ECU 92 and the engine drive state detection unit 84 are shown separately in FIG. 6, the engine drive state detection unit 84 may be included in the main ECU 92.

  Next, the wiper drive control processing according to the second embodiment will be described with reference to FIG. 7. In step 110, the wiper ECU 58 determines, based on the contact position of the wiper switch 50, whether to drive the wiper motor 18 to wipe the windshield glass 12 back and forth by the wipers 14 and 16. If the determination in step 110 is negative, the determination in step 110 is repeated.

  If the determination in step 110 is affirmative, the process proceeds to step 112. In step 112, the wiper ECU 58 acquires the drive state of the engine from the main ECU 92 (engine drive state detection unit 84) and determines whether or not the engine is being driven. When the engine has stopped driving, the determination at step 112 is denied and the routine proceeds to step 114, at which the wiper ECU 58 determines that the vehicle speed V detected by the vehicle speed sensor 51 is not less than the first threshold value Vth1. It is determined whether or not.

  If the determination in step 114 is negative, the process proceeds to step 116, and in step 116, the wiper ECU 58 sets the frequency at the low volume as the frequency of the PWM signal. When the determination in step 114 is affirmative, the process proceeds to step 118, and in step 118, the wiper ECU 58 sets the frequency at the loud volume as the frequency of the PWM signal.

  On the other hand, when the engine is driven, the determination at step 112 is affirmative and the routine proceeds to step 120, where the wiper ECU 58 causes the wiper ECU 58 to determine that the vehicle speed V detected by the vehicle speed sensor 51 is not less than the second threshold value Vth2. It is determined whether or not. The second threshold value Vth2 <the first threshold value Vth1.

  If the determination in step 120 is negative, the process proceeds to step 122, and in step 122, the wiper ECU 58 sets the frequency at the low volume as the frequency of the PWM signal. Further, when the determination in step 120 is affirmative, the process proceeds to step 124, and in step 124, the wiper ECU 58 sets the frequency at the loud volume as the frequency of the PWM signal.

  When any one of steps 116, 118, 122, and 124 is performed, the process proceeds to step 126. In step 126, the wiper ECU 58 drives the wiper motor 18 by the PWM signal having the frequency set in any of steps 116, 118, 122 and 124 to wipe the windshield glass 12 back and forth by the wipers 14 and 16, and then in step 110. Return.

  In the case of a hybrid vehicle, the engine may stop driving even when the vehicle is running, and the volume in the vehicle compartment changes depending on whether the engine is driving. In other words, in a hybrid vehicle capable of switching between motor drive and engine drive, the volume in the vehicle compartment changes between when the motor is driven and when the engine is driven. On the other hand, in the second embodiment, as the threshold value for the speed V of the vehicle, the first threshold value Vth1 is set when the engine stops driving (motor is driven), and the first threshold value Vth1 is set when the engine is driving. The frequency of the PWM signal is switched by using the two threshold values Vth2 (Vth1> Vth2). As a result, even in a hybrid vehicle capable of switching between motor driving and engine driving, it is possible to suppress power consumption of the wiper motor 18 while suppressing audible sounds from being heard by passengers.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. Since the third embodiment has the same configuration as the second embodiment, the same reference numerals are given to the respective parts and the description thereof will be omitted.

  As shown in FIG. 8, in the wiper drive control process according to the third embodiment, in step 130, the wiper ECU 58 drives the wiper motor 18 based on the contact position of the wiper switch 50 to cause the windshields 14 and 16 to windshield. It is determined whether or not the glass 12 is wiped back and forth. If the determination in step 130 is negative, the determination in step 130 is repeated.

  If the determination in step 130 is affirmative, the process proceeds to step 132. In step 132, the wiper ECU 58 obtains the volume evaluation value W1 for evaluating the volume of the vehicle interior due to the vehicle speed, based on the vehicle speed V detected by the vehicle speed sensor 51. Specifically, as shown in FIG. 9A as an example, a map defining the relationship between the vehicle speed and the volume evaluation value W1 is defined, and the volume evaluation value W1 corresponding to the current vehicle speed V is set. Get from the map. The map in FIG. 9A is an example, and the vehicle speed and the sound volume evaluation value W1 may not be in a proportional relationship.

  In the next step 134, the wiper ECU 58 causes the wiper switch 50 to determine the wiper 14, which is different depending on the low speed operation position (LOW), the intermittent operation position (INT), or the high speed operation position (HIGH), based on the wiper wiping speed. A sound volume evaluation value W2 for evaluating the sound volume in the vehicle compartment due to the wiping speed of 16 is acquired. Specifically, as shown in FIG. 9B as an example, a map defining the relationship between the wiping speed of the wipers 14 and 16 and the sound volume evaluation value W2 is set, and the current wiping speed of the wipers 14 and 16 is set. The volume evaluation value W2 corresponding to is acquired from the map.

  Subsequently, in step 136, the wiper ECU 58 acquires the engine drive state from the main ECU 92, and based on the acquired engine drive state, the volume evaluation value W3 for evaluating the volume of the vehicle interior due to the engine drive state. To get. Specifically, as shown in FIG. 9C as an example, a map defining the relationship between the engine drive state and the volume evaluation value W3 is defined, and the volume evaluation value corresponding to the current engine drive state is set. Get W3 from the map.

  In step 138, the wiper ECU 58 calculates the sound volume evaluation value W for comprehensively evaluating the sound volume in the vehicle interior by adding the sound volume evaluation values W1, W2, W3. The volume evaluation value W is not limited to the simple calculation of the volume evaluation values W1, W2, W3, and the logarithm of the value obtained by adding the volume evaluation values W1, W2, W3, etc. May be In step 140, the wiper ECU 58 determines whether the volume evaluation value W calculated in step 138 is equal to or greater than the threshold value Wth.

  If the determination in step 140 is negative, the process proceeds to step 142, and in step 142, the wiper ECU 58 sets the frequency at the low volume as the frequency of the PWM signal. When the determination in step 140 is affirmative, the process proceeds to step 144, and in step 144, the wiper ECU 58 sets the frequency at the loud volume as the frequency of the PWM signal.

  When the process of step 142 or step 144 is performed, the process proceeds to step 146. In step 146, the wiper ECU 58 drives the wiper motor 18 by the PWM signal of the frequency set in step 142 or step 144 to wipe the windshield glass 12 back and forth by the wipers 14 and 16, and then returns to step 130.

  In the third embodiment, in addition to the speed of the vehicle and the driving state of the engine, the sound volume evaluation value W for evaluating the sound volume in the passenger compartment is obtained in consideration of the wiping speed of the wipers 14 and 16, and the sound volume evaluation value W with respect to the threshold value Wth is obtained. The frequency of the PWM signal is switched according to the magnitude relationship of. Thereby, the volume in the vehicle compartment can be evaluated more accurately.

  In the above description, the mode in which the volume of the vehicle interior is estimated (evaluated) based on the vehicle speed, the engine driving state, the wiping speed of the wipers 14 and 16, and the frequency of the PWM signal is switched has been described. It is not limited. The following modes are conceivable as modes for indirectly estimating (evaluating) the volume in the vehicle compartment and switching the frequency of the PWM signal.

  For example, as shown in FIG. 6, when the air conditioner is turned on by an air conditioner switch 85 as a first detection unit that detects the on / off of an air conditioner such as an air conditioner installed in a vehicle, the air conditioner is detected as off. The frequency of the PWM signal may be set to be lower than that in the case.

  Further, for example, as shown in FIG. 6, the air volume detection unit 86 as a second detection unit that detects the air volume by the air conditioner such as an air conditioner mounted on the vehicle detects that the air volume by the air conditioner is equal to or more than a predetermined value. In this case, the frequency of the PWM signal may be set lower than when the air volume of the air conditioner is less than the predetermined value.

  Further, for example, as shown in FIG. 6, when the rain amount detected by the rain sensor 87 as the rain amount detecting unit is equal to or more than a predetermined value, the frequency of the PWM signal is made lower than when the detected rain amount is less than the predetermined value. You may do it. An in-vehicle camera may be provided separately from the rain sensor 87 as the raindrop detection unit.

  Further, for example, as shown in FIG. 6, when the audio device is detected to be on by an audio switch 88 as a third detection unit which detects the on / off of the audio device mounted on the vehicle, the audio device is detected to be off. The frequency of the PWM signal may be set to be lower than that in the case. The off state of the audio device may include a mute state.

  Further, for example, as shown in FIG. 6, when the audio volume detection unit 89 as a fourth detection unit that detects the volume of the audio device mounted on the vehicle detects that the volume of the audio device is equal to or higher than a predetermined value. In addition, the frequency of the PWM signal may be set lower than when the volume of the audio device is less than the predetermined value.

  Further, as shown in FIG. 6, for example, when it is detected that at least one of the side window and the sunroof is in an open state by the opening / closing detection unit 90 as a fifth detection unit that detects the opening / closing of the side window of the vehicle or the sunroof. The frequency of the PWM signal may be set lower than that when the side windows and the sunroof are closed. The open / close detection unit 90 can be configured to include, for example, a sensor magnet that detects the rotational positions of the power window motor and the sunroof motor, and a Hall IC.

  Further, for example, as shown in FIG. 6, the GPS device 91 as the sixth detection unit for detecting whether the road on which the vehicle is traveling is a highway or a general road, and it is detected that the vehicle is traveling on the highway. In this case, the frequency of the PWM signal may be lower than that when the vehicle is traveling on a general road. Specifically, whether the vehicle is traveling on a highway is detected based on the position information detected by the GPS device 91 and the map information provided on the vehicle.

  In each of the above-described modes, the volume of the vehicle interior is indirectly estimated (evaluated) and the frequency of the PWM signal is switched, and it is not necessary to separately provide a means for detecting the volume of the vehicle interior. The number of parts can be reduced. However, the present invention is not limited to each of the above-described aspects, and a volume detecting means for detecting the volume of the vehicle interior is provided, and when the volume of the vehicle interior detected by the volume detecting means is a predetermined value or more, The frequency of the PWM signal may be set lower than that when the volume in the room is less than the predetermined value.

  Further, although the wiper motor 18 has been described above as an example of the motor, the present invention is not limited to this, and a power window motor for raising and lowering a side window and a motor used as a drive source for a vehicle in a hybrid vehicle or an electric vehicle. It is also possible to apply to.

10 ... Wiper control device, 14, 16 ... Wiper, 18 ... Wiper motor, 22 ... Wiper control unit, 50 ... Wiper switch, 51 ... Vehicle speed sensor, 56 ... Drive circuit, 56B ... Driver, 56A ... Pre-driver, 58 ... Wiper ECU , 56A ... Pre-driver, 56B ... Driver, Tr1, Tr2, Tr3, Tr4 ... Transistor, 92 ... Main ECU, 100 ... Wiper device

Claims (11)

A motor mounted on the vehicle,
A first switching element capable of opening / closing between one end of the winding of the motor and a power feeding end, a second switching element capable of opening / closing between the other end of the winding of the motor and the power feeding end, winding of the motor A driving unit including a third switching element capable of opening / closing between one end of the wire and a ground end, and a fourth switching element capable of opening / closing between the other end of the winding of the motor and the ground end;
A control unit that supplies a PWM signal for driving the motor by PWM to each switching element of the drive unit, and controls the frequency of the PWM signal according to the volume of the vehicle interior of the vehicle.
A motor device for a vehicle including the.   The vehicle motor device according to claim 1, wherein the control unit lowers the frequency of the PWM signal when the volume of the vehicle interior of the vehicle is a predetermined value or more than when the volume of the vehicle interior is less than the predetermined value. .   The control unit lowers the frequency of the PWM signal when the vehicle speed detected by the vehicle speed detection unit that detects the speed of the vehicle is a predetermined value or more than when the vehicle speed is less than the predetermined value. The motor device for a vehicle according to claim 2.   The control unit detects the ON / OFF state of the air conditioner mounted on the vehicle when the ON state of the air conditioner is detected by the first detection unit, and the PWM signal is detected more than when the OFF state of the air conditioner is detected. The vehicle motor device according to any one of claims 1 to 3, wherein the frequency is reduced.   When the second detection unit that detects the air volume of the air conditioner mounted on the vehicle detects that the air volume is equal to or more than a predetermined value, the control unit is more likely to operate than the case where the air volume is less than the predetermined value. The vehicle motor device according to claim 1, wherein the frequency of the PWM signal is lowered.   When the wiping speed set by the wiper switch that sets the wiping speed of the wiper device mounted on the vehicle is equal to or higher than a predetermined value, the control unit outputs the PWM signal more than when the wiping speed is lower than the predetermined value. The vehicle motor device according to any one of claims 1 to 5, wherein the frequency is reduced.   The control unit lowers the frequency of the PWM signal when the amount of rainfall detected by the rainfall amount detection unit is equal to or more than a predetermined value, compared with the case where the amount of rainfall is less than the predetermined value. A motor device for a vehicle according to the item.   The control unit may detect the ON / OFF state of the audio device mounted on the vehicle, when the ON / OFF state of the audio device is detected by the third detection unit, as compared to when the OFF state of the audio device is detected. 9. The vehicle motor device according to claim 1, wherein the frequency of the motor is reduced.   When the fourth detection unit that detects the volume of the audio device mounted on the vehicle detects that the volume is equal to or higher than a predetermined value, the control unit is more likely than the case where the volume is lower than the predetermined value. 9. The vehicle motor device according to claim 1, wherein the frequency of the PWM signal is lowered. The vehicle is equipped with an engine, and the engine is selectively driven while an ignition switch is on.
The vehicle according to any one of claims 1 to 9, wherein the control unit lowers the frequency of the PWM signal when the engine is driven, compared to when the drive of the engine is stopped. Motor device.   The vehicle motor device according to any one of claims 1 to 10, wherein the motor is a wiper motor.