JP7020364B2 - Vehicle motor device - Google Patents

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.

Japanese Patent No. 6294138

When an in-vehicle motor such as a wiper motor is driven by PWM, the motor (coil) vibrates at the frequency of the PWM signal as the transistor is turned on and off. Therefore, in order to suppress the vibration of the motor (coil) from being heard by the occupants of the vehicle as audible sounds and causing discomfort to the occupants, the frequency of the PWM signal is on the higher frequency side 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 to the PWM signal increases, and the efficiency of driving the motor decreases. Therefore, the frequency of the PWM signal should be set to a higher frequency side than the audible range. Has a problem that it leads to an increase in 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 the power consumption of a motor while suppressing the audible sound from being heard by the occupants of the vehicle. Is.

The vehicle motor device according to the 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 feeding end, and a winding of the motor. A second switching element that can be opened and closed between the other end of the motor and the feeding end, a third switching element that can be opened and closed between one end of the winding of the motor and the ground end, and the winding of the motor. A drive unit including a fourth switching element that can be opened and closed between the 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 is used. It includes a control unit that controls the frequency according to the volume in the vehicle interior of the vehicle.

In the first aspect of the present invention, the first switching element, the second switching element, the third switching element and the fourth switching element of the driving unit form an H-bridge circuit, and PWM for driving the 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 of the vehicle interior of the vehicle.

As a result, when the vehicle interior is in a volume condition in which the vibration of the motor (winding) due to the on / off of the switching element is difficult to be heard as an audible sound by the occupants of the vehicle, 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 size becomes smaller and the efficiency of driving the motor is improved. Therefore, according to the first aspect of the present invention, it is possible to suppress the power consumption of the motor while suppressing the audible sound from being heard by the occupants of the vehicle.

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

As a result, when the vibration of the motor due to the on / off of the switching element is in a volume condition where it is difficult for the occupants of the vehicle to hear it as an audible sound, the frequency of the PWM signal is lowered to reduce the time ratio of the dead time to the PWM signal. It can be made smaller to improve the efficiency of driving the motor.

A third aspect of the present invention is the first or second aspect of the present invention, wherein the control unit is described when the vehicle speed detected by the vehicle speed detection unit that detects the speed of the vehicle is a predetermined value or more. The frequency of the PWM signal is lower than when the vehicle speed is less than a predetermined value.

In the third aspect of the present invention, based on the vehicle speed detected by the vehicle speed detection unit, it is indirectly estimated that the vibration of the motor due to the on / off of the switching element is hard to be heard as an audible sound by the occupants of the vehicle. There is. This eliminates the need to separately provide a means for detecting the volume in the vehicle interior, and can reduce the number of parts of the device.

A fourth aspect of the present invention is, in any one of the first to third aspects of the present invention, the control unit is the air conditioner by the first detection unit that detects the on / off of the air conditioner mounted on the vehicle. When the on is detected, the frequency of the PWM signal is lowered as compared with the case where the off of the air conditioner is detected.

In the fourth aspect of the present invention, based on the on / off of the air conditioner mounted on the vehicle, it is indirectly estimated that the vibration of the motor due to the on / off of the switching element is hard to be heard as an audible sound by the occupants of the vehicle. ing. This eliminates the need to separately provide a means for detecting the volume in the vehicle interior, and can reduce the number of parts of the device.

A fifth aspect of the present invention is, in any one of the first to fourth aspects of the present invention, the control unit has the air volume measured by a second detection unit that detects the air volume by the air conditioner mounted on the vehicle. When it is detected that the value is equal to or higher than the predetermined value, the frequency of the PWM signal is lowered as compared with the case where the air volume is less than the predetermined value.

In the fifth aspect of the present invention, based on the air volume of the air conditioner mounted on the vehicle, it is indirectly estimated that the vibration of the motor due to the on / off of the switching element is hard to be heard as an audible sound by the occupants of the vehicle. ing. This eliminates the need to separately provide a means for detecting the volume in the vehicle interior, and can reduce the number of parts of the device.

A sixth aspect of the present invention is, in any one of the first to fifth aspects of the present invention, the control unit is set by a wiper switch for setting a wiping speed by a wiper device mounted on the vehicle. When the wiping speed is at least a predetermined value, the frequency of the PWM signal is lower than when the wiping speed is less than a predetermined value.

In the sixth aspect of the present invention, it is indirectly estimated that the vibration of the motor due to the on / off of the switching element is hard to be heard as an audible sound by the occupants of the vehicle based on the wiping speed by the wiper device mounted on the vehicle. is doing. This eliminates the need to separately provide a means for detecting the volume in the vehicle interior, and can reduce the number of parts of the device.

A seventh aspect of the present invention is, in any one of the first to sixth aspects of the present invention, the control unit has a predetermined value when the amount of rainfall detected by the rainfall detection unit is equal to or greater than a predetermined value. The frequency of the PWM signal is lower than that in the case of less than.

In the seventh aspect of the present invention, based on the amount of rainfall, it is indirectly estimated that the vibration of the motor due to the on / off of the switching element is hard to be heard as an audible sound by the occupants of the vehicle. This eliminates the need to separately provide a means for detecting the volume in the vehicle interior, and can reduce the number of parts of the device.

An eighth aspect of the present invention is, in any one of the first to seventh aspects of the present invention, the control unit is the audio device by a third detection unit that detects on / off of the audio device mounted on the vehicle. When the on is detected, the frequency of the PWM signal is lowered as compared with the case where the off of the audio device is detected.

In the eighth aspect of the present invention, based on the on / off of the audio device mounted on the vehicle, it is indirectly estimated that the vibration of the motor due to the on / off of the switching element is hard to be heard as an audible sound by the occupants of the vehicle. ing. This eliminates the need to separately provide a means for detecting the volume in the vehicle interior, and can reduce the number of parts of the device.

A ninth aspect of the present invention is, in any one of the first to eighth aspects of the present invention, the control unit has the volume measured by a fourth detection unit that detects the volume by an 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 lowered as compared with the case where the volume is lower than the predetermined value.

In the ninth aspect of the present invention, based on the volume of the audio device mounted on the vehicle, it is indirectly estimated that the vibration of the motor due to the on / off of the switching element is hard to be heard as an audible sound by the occupants of the vehicle. ing. This eliminates the need to separately provide a means for detecting the volume in the vehicle interior, and can reduce the number of parts of the device.

A tenth aspect of the present invention is any of the first to ninth aspects of the present invention, wherein the vehicle is equipped with an engine and the engine is selectively driven while the ignition switch is on. The control unit lowers the frequency of the PWM signal when the engine is driven than when the engine is stopped.

In the tenth aspect of the present invention, based on the driving condition of the engine mounted on the vehicle, the volume condition in which the vibration of the motor due to the on / off of the switching element is hard to be heard as an audible sound by the occupant of the vehicle is indirectly estimated. ing. This eliminates the need to separately provide a means for detecting the volume in the vehicle interior, and can reduce the number of parts of the device.

In the eleventh aspect of the present invention, in any one of the first to tenth aspects of the present invention, the motor is a wiper motor.

The wiper motor is arranged near the passenger compartment of the vehicle, and the vibration of the motor due to the on / off of the switching element is easily heard by the occupants of the vehicle as an audible sound, which is suitable for the present invention.

It is a schematic diagram which shows the structure of the wiper apparatus which concerns on 1st Embodiment. It is a block diagram which shows the structure of the wiper control device which concerns on embodiment. It is a flowchart which shows the wiper drive control processing which concerns on 1st Embodiment. It is a timing chart which shows an example of the PWM signal at the time of low volume and the time of loud volume. It is a timing chart which shows the example of the switching of the frequency of the PWM signal with respect to the change of the vehicle speed. It is a schematic diagram which shows the structure of the wiper apparatus which concerns on 2nd Embodiment and 3rd Embodiment. It is a flowchart which shows the wiper drive control processing which concerns on 2nd Embodiment. It is a flowchart which shows the wiper drive control processing which concerns on 3rd Embodiment. It is a diagram which shows an example of the 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, the wiper device 100 according to the embodiment is a device for wiping the windshield glass 12 provided in a vehicle such as a passenger car, and is a pair of wipers 14, 16, a pair of wipers 14, a wiper motor 18, a link mechanism 20, and a link mechanism 20. The wiper control device 10 is included. In this embodiment, the wiper motor 18 is a DC motor with a brush. The wiper motor 18 is an example of a motor.

The wiper 14 includes a wiper arm 24 whose base end is fixed to the pivot shaft 42 and a wiper blade 28 connected to the tip of the wiper arm 24, and the wiper 16 has a base end portion to the pivot shaft 44. The wiper arm 26 connected and the wiper blade 30 fixed to the tip end portion of the wiper arm 26 are included. When the wiper arms 24 and 26 are rotated around 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 move back and forth on the windshield glass 12. Wipe off 12.

The wiper motor 18 has an output shaft 32 that is decelerated by a reduction mechanism 52 mainly composed of a worm gear and is rotated forward and backward 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 side of the crank arm 34 is fixed to the output shaft 32 of the wiper motor 18, and the other end side of the crank arm 34 is rotatably connected to one end side of the first link rod 36. Further, the other end side of the first link rod 36 is rotatably connected to the intermediate portion of the pivot lever 38. One end of the second link rod 46 is rotatably connected to the end of the pivot lever 38 opposite to the end fixed to the pivot shaft 42, and the other end is the pivot lever 40. Of these, it is rotatably connected to the 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 of the pivot levers 38 and 40 on the side fixed to the pivot shafts 42 and 44 is The wiper arms 24 and 26 are connected to each other via the pivot shafts 42 and 44, respectively.

In the wiper device 100, the output shaft 32 of the wiper motor 18 is rotated in the forward and reverse directions in 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 to be transmitted to the wiper arms 24 and 26. The wiper blades 28 and 30 reciprocate between the lower inversion position P2 and the upper inversion position P1 on the windshield glass 12 with the reciprocating rotation of the windshield wiper blades 28 and 30. 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 °.

Further, the storage position P3 is provided below the lower inversion position P2. The wiper blades 28 and 30 move to the storage position P3 by rotating the output shaft 32 by the rotation angle θ2 from the state where the wiper blades 28 and 30 are in the downward inversion position P2. 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 θ2 = 10 ° as an example. When the rotation angle θ2 = 0 °, the lower inversion position P2 and the storage position P3 coincide with each other, and the wiper blades 28 and 30 stop at the lower inversion position P2 and are stored. When the rotation angle θ2 = 0 °, the lower inversion position P and the storage position P3 may be matched by setting, for example, the rotation angle θ1 = 150 °.

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 positions the wiper blades 28 and 30 on the windshield glass 12 and rotates 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 deceleration mechanism 52 of the wiper motor 18, and converts the magnetic field (magnetic force) of the sensor magnet that rotates in conjunction with the output shaft 32 into an electric current for detection.

In the present embodiment, since the output shaft 32 of the wiper motor 18 is decelerated by the deceleration 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 main body. However, in the present embodiment, the wiper motor main body and the reduction mechanism 52 are integrally inseparably configured. Therefore, hereinafter, the rotation speed and the rotation angle of the output shaft 32 are regarded as the rotation speed and the rotation angle of the wiper motor 18. The data related to the control of the drive circuit 56 is stored in advance in the storage unit 58C.

Further, the wiper switch 50 and the vehicle speed sensor 51 are connected to the wiper ECU 58 of the wiper control unit 22 via a main ECU 92 that controls the engine of the vehicle and the like. The wiper switch 50 is a switch that turns on or off the electric power supplied from the vehicle battery 80 to the wiper motor 18. The wiper switch 50 has 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 wiper blades 28 and 30, an intermittent operation position (INT) for intermittent operation at regular intervals, 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 speed V of the vehicle, and the speed V of the vehicle detected by the vehicle speed sensor 51 is output to the wiper ECU 58 via the main ECU 92.

When the contact position of the wiper switch 50 input as a command signal is a high-speed operating position, the wiper ECU 58 rotates the output shaft 32 of the wiper motor 18 at high speed, and the contact position of the wiper switch 50 input as a command signal is low speed. In the case of the operating position, the output shaft 32 of the wiper motor 18 is rotated at a low speed. Further, in the wiper ECU 58, when the contact position of the wiper switch 50 input as a command signal is the intermittent operation position, the wiper blades 28 and 30 reciprocate between the upper inversion position P1 and the lower inversion position P2, and lower. The wiper motor 18 is intermittently rotated so as to stop at the inversion position P2 for a predetermined time. The wiper switch 50 may have an automatic operation position (AUTO) that changes the rotation speed of the output shaft 32 of the wiper motor 18 according to the detection result of rainfall or raindrops by the rain sensor or the vehicle-mounted camera.

As shown in FIG. 2, the electric power of the battery 80 is supplied to the wiper ECU 58 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 the ground region.

Further, the wiper ECU 58 is connected to a rotation angle sensor 54 that detects the magnetic field of the sensor magnet 70 that changes according to the rotation of the output shaft 32. The wiper ECU 58 detects the positions of the wiper blades 28 and 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 rotation speed data of the wiper motor 18 defined in advance according to the positions of the wiper blades 28 and 30 stored in the storage unit 58C, and the rotation of the wiper motor 18 is specified by the wiper blade. The drive circuit 56 is controlled so that the rotation speed corresponds to the positions of 28 and 30.

The drive circuit 56 includes a pre-driver 56A that generates a PWM signal that turns on and off the transistor of the driver 56B at a frequency and a duty ratio specified by the control signal based on a control signal input from the wiper ECU 58, and four transistors Tr1 and The transistors Tr1, Tr2, Tr3, and Tr4 are turned on and off (the drive circuit 56 is opened and closed by the transistors Tr1, Tr2, Tr3, and Tr4) according to the PWM signal output by the predriver 56A including Tr2, Tr3, and Tr4, and the coil of the wiper motor 18 is used. It includes a driver 56B that energizes and.

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. Further, 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, and 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. Further, the sources of the transistors Tr3 and Tr4 are grounded. Further, 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. .. As described above, the transistors Tr1, Tr2, Tr3, and 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. Further, when the transistor Tr1 is turned off (when the transistor Tr1 is 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 on the outward path, the predriver 56A always turns on the transistor Tr1, turns the transistor Tr4 on and off in small steps at a predetermined duty ratio, and turns the transistor Tr2 into the transistor Tr4, as shown in FIG. A PWM signal to be turned on when is off is supplied to the driver 56B. 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 flows without passing through the wiper motor 18, which causes a failure of the wiper device 100 and the like. Therefore, the above PWM signal has a dead time (time when the transistor Tr1 is turned on and both the transistors Tr2 and Tr4 are turned off) in order to prevent a through current, as shown by being surrounded by a broken line in FIG. 4 as an example. It is provided. Due to the above PWM signal, for example, a motor current in the direction of operating the wipers 14 and 16 in the outward path flows through the wiper motor 18 (motor current flows so as to rotate the output shaft 32 of the wiper motor 18 in the forward direction).

Further, for example, when the wipers 14 and 16 are operated in the return path, the predriver 56A always turns on the transistor Tr2, turns the transistor Tr3 on and off in small steps at a predetermined duty ratio, and turns on the transistor Tr1 when the transistor Tr3 is off. A 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 flows without passing through the wiper motor 18, which causes a failure of the wiper device 100 and the like. Therefore, the above PWM signal is also provided with a dead time (time for turning on the transistor Tr2 and turning off both the transistors Tr1 and Tr3) in order to prevent the penetration current. Due to the above PWM signal, for example, a motor current in the direction of returning the wipers 14 and 16 flows through the wiper motor 18 (motor current flows so as to rotate the output shaft 32 of the wiper motor 18 in the forward direction).

A reverse connection protection circuit 64 and a noise prevention coil 66 are provided between the battery 80 as a power source and the drive circuit 56, and an electrolytic capacitor C2 is connected in parallel with the drive circuit 56. The noise prevention coil 66 suppresses noise generated by 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 reverse direction of FIG. As an example, the reverse connection protection circuit 64 is composed of a so-called diode-connected FET or the like in which its own drain and gate are connected.

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 end of the voltage dividing circuit configured 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 end of the voltage divider circuit configured by the chip thermistor RT, and if the temperature exceeds a predetermined threshold temperature, the wiper control The operation of the device 10 is stopped.

Further, a current detection unit 82 for detecting the current (motor current) between the coil of the wiper motor 18 and the driver 56B is provided between the source of the transistors Tr3 and Tr4 included in the driver 56B and the battery 80. .. The current detection unit 82 detects the potential difference between 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 signal of the detected potential difference. Includes amplifier 82B. The wiper ECU 58 calculates the current value of the motor current from the signal output by the amplifier 82B.

Next, as the operation of the first embodiment, the 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 by the wipers 14, 16 based on whether the wiper switch 50 is in the low speed operation position (LOW), high speed operation position (HIGH), or 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 in step 100 is denied and the determination in step 100 is repeated.

When the wiper switch 50 is in the low speed operation position (LOW), high speed operation position (HIGH), or intermittent operation position (INT), the determination in step 100 is affirmed and the process proceeds to step 102. In step 102, the wiper ECU 58 determines whether or not the speed V of the vehicle detected by the vehicle speed sensor 51 is equal to or greater than a predetermined threshold value Vth. When the determination in step 102 is denied, it can be estimated that the vehicle interior of the vehicle is relatively quiet (the noise in the vehicle interior is small) because the volume of the wind noise associated with the traveling of the vehicle is relatively low, for example. Therefore, when driving the wiper motor 18, it can be determined that the vibration accompanying the on / off of the transistors Tr1, Tr2, Tr3, and Tr4 is easily heard by the occupants of the vehicle as an audible sound.

Therefore, if the determination in step 102 is denied, the process proceeds to step 104, and in step 104, the wiper ECU 58 sets the frequency at low volume as the frequency of the PWM signal. The frequency at low volume is set to a frequency at which the vibration caused by turning on and off the transistors Tr1, Tr2, Tr3, and Tr4 is difficult for the occupants of the vehicle to hear as audible sound (an example is shown in FIG. 4 (A)), which is an example. Can be 20 [kHz]. As a result, the vibration caused by the on / off of the transistors Tr1, Tr2, Tr3, and Tr4 is suppressed from being heard as an audible sound by the occupants of the vehicle.

If the determination in step 102 is affirmed, it can be estimated that, for example, the volume of the wind noise associated with the traveling of the vehicle is relatively loud, and the interior of the vehicle is relatively loud (the noise inside the vehicle is loud). Therefore, even when driving the wiper motor 18, the vibration caused by turning on and off the transistors Tr1, Tr2, Tr3, and Tr4 is masked by other sounds even if the frequency of the vibration is within the audible range, and is masked by the occupant of the vehicle. It can be judged that it is difficult to hear as an audible sound.

Therefore, if the determination in step 102 is affirmed, the process proceeds to step 106, and in step 106, the wiper ECU 58 sets the frequency at the time of high volume as the frequency of the PWM signal. The frequency at high volume is set to a frequency that can improve the driving efficiency of the wiper motor 18 and suppress the power consumption by reducing the time ratio of the dead time to the PWM signal (an example is shown in the figure). 4 (B)), for example, 10 [kHz] can be set. For example, if the frequency of the PWM signal is halved (from 20 [kHz] to 10 [kHz]), the frequency of appearance of the dead time in a predetermined time becomes 50%, and the driving 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 reciprocate the windshield glass 12 by the wipers 14 and 16, and returns to step 100.

As a result, as shown in FIG. 5, when the speed V of the vehicle is less than the predetermined threshold value Vth, the frequency of the PWM signal is set to the frequency at the time of low volume, so that the transistors Tr1, Tr2, Tr3, It is possible to suppress the vibration accompanying the on / off of the Tr4 from being heard as an audible sound by the occupants of the vehicle. Further, when the speed V of the vehicle becomes equal to or higher than a predetermined threshold value Vth, the frequency of the PWM signal is set to the frequency at the time of high volume to improve the driving efficiency of the wiper motor 18 and suppress the power consumption. be able to.

The threshold value Vth of the vehicle speed V may be different depending on whether the vehicle speed V is increasing or decreasing. For example, in a vehicle powered by an engine, when the speed V of the vehicle is increasing, the volume of the vehicle interior is increased by the engine or the like as a sound source as compared with the case where the speed V of the vehicle is decreasing. Since it is estimated to be larger, the threshold Vth may be set to a smaller value (threshold Vth when the vehicle speed V increases <threshold 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 equipped with an engine and a motor as a power source. The drive / stop of the engine is controlled by the main ECU 92. The drive / drive stop state of the engine 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 separately shown in FIG. 6, the engine drive state detection unit 84 may be included in the main ECU 92.

Next, the wiper drive control process according to the second embodiment will be described with reference to FIG. 7. In step 110, the wiper ECU 58 determines whether or not the wiper motor 18 is driven to wipe the windshield glass 12 reciprocally by the wipers 14 and 16 based on the contact position of the wiper switch 50. If the determination in step 110 is denied, the determination in step 110 is repeated.

If the determination in step 110 is affirmed, 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 is stopped, the determination in step 112 is denied and the process proceeds to step 114. In step 114, the wiper ECU 58 has the vehicle speed V detected by the vehicle speed sensor 51 equal to or higher than the first threshold value Vth1. Judge whether or not.

If the determination in step 114 is denied, the process proceeds to step 116, and in step 116, the wiper ECU 58 sets the frequency at low volume as the frequency of the PWM signal. If the determination in step 114 is affirmed, the process proceeds to step 118, and in step 118, the wiper ECU 58 sets the frequency at the time of high volume as the frequency of the PWM signal.

On the other hand, when the engine is being driven, the determination in step 112 is affirmed and the process proceeds to step 120. In step 120, the wiper ECU 58 has the vehicle speed V detected by the vehicle speed sensor 51 equal to or higher than the second threshold value Vth2. Judge whether or not. The second threshold value Vth2 <first threshold value Vth1.

If the determination in step 120 is denied, the process proceeds to step 122, and in step 122, the wiper ECU 58 sets the frequency at low volume as the frequency of the PWM signal. If the determination in step 120 is affirmed, the process proceeds to step 124, and in step 124, the wiper ECU 58 sets the frequency at the time of high volume as the frequency of the PWM signal.

When any of the processes 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 of the frequency set in any of steps 116, 118, 122, 124 to reciprocate the windshield glass 12 by the wipers 14 and 16, and causes step 110. return.

In the case of a hybrid vehicle, the engine may stop driving even while the vehicle is running, and the volume in the vehicle interior changes depending on whether the engine is driving or not. In other words, it is a hybrid vehicle that can switch between motor drive and engine drive, and the volume inside the vehicle interior changes between when the motor is driven and when the engine is driven. On the other hand, in the second embodiment, as a threshold value for the speed V of the vehicle, the first threshold value Vth1 is used when the engine is stopped (motor driven), and the first threshold value Vth1 is used when the engine is driven. The frequency of the PWM signal is switched using the two threshold values Vth2 (Vth1> Vth2). As a result, even in a hybrid vehicle capable of switching between motor drive and engine drive, it is possible to suppress the power consumption of the wiper motor 18 while suppressing the audible sound from being heard by the occupants.

[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 and windshields the wipers 14 and 16. It is determined whether or not the glass 12 is wiped back and forth. If the determination in step 130 is denied, the determination in step 130 is repeated.

If the determination in step 130 is affirmed, the process proceeds to step 132. In step 132, the wiper ECU 58 acquires a volume evaluation value W1 for evaluating the volume in the vehicle interior due to the speed of the vehicle based on the speed V of the vehicle 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 defined. From the map. The map of FIG. 9A is an example, and the speed of the vehicle and the volume evaluation value W1 do not have to be in a proportional relationship.

In the next step 134, the wiper ECU 58 determines the wiper 14, based on the wiper wiping speed at which the wiper switch 50 differs depending on the low speed operating position (LOW) or the intermittent operating position (INT) or the high speed operating position (HIGH). The volume evaluation value W2 for evaluating the volume in the vehicle interior due to the wiping speed of 16 is acquired. Specifically, as shown in FIG. 9B as an example, a map that defines the relationship between the wiping speeds of the wipers 14 and 16 and the volume evaluation value W2 is defined, and the current wiping speeds of the wipers 14 and 16 are defined. The volume evaluation value W2 corresponding to is acquired from the map.

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

In step 138, the wiper ECU 58 calculates the volume evaluation value W that comprehensively evaluates the volume in the vehicle interior by adding the volume evaluation values W1, W2, and W3. The volume evaluation value W is not limited to being calculated by simply adding the volume evaluation values W1, W2, and W3, but is a logarithmic value obtained by adding the volume evaluation values W1, W2, and W3. May be. In step 140, the wiper ECU 58 determines whether or not 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 denied, the process proceeds to step 142, and in step 142, the wiper ECU 58 sets the frequency at low volume as the frequency of the PWM signal. If the determination in step 140 is affirmed, the process proceeds to step 144, and in step 144, the wiper ECU 58 sets the frequency at the time of high 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 reciprocally wipe the windshield glass 12 by the wipers 14 and 16, and returns to step 130.

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

In the above, the mode of estimating (evaluating) the volume in the vehicle interior based on the speed of the vehicle, the driving state of the engine, the wiping speed of the wipers 14 and 16, and switching the frequency of the PWM signal has been described. Not limited. The following modes can be considered as modes for indirectly estimating (evaluating) the volume in the vehicle interior and switching the frequency of the PWM signal.

For example, as shown in FIG. 6, when the on / off of the air conditioner is detected by the air conditioner switch 85 as the first detection unit for detecting the on / off of the air conditioner such as the air conditioner mounted on the vehicle, the off of the air conditioner is detected. The frequency of the PWM signal may be lower than that in the case of the above.

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

Further, for example, as shown in FIG. 6, when the rainfall detected by the rain sensor 87 as the rainfall detection unit is equal to or more than a predetermined value, the frequency of the PWM signal is lowered as compared with the case where the detected rainfall is less than the predetermined value. You may do so. In addition to the rain sensor 87, an in-vehicle camera may be provided as the raindrop detection unit.

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

Further, for example, when it is detected by the audio volume detection unit 89 as the fourth detection unit that detects the volume by the audio device mounted on the vehicle that the volume by the audio device is equal to or higher than a predetermined value, as shown in FIG. In addition, the frequency of the PWM signal may be lower than when the volume of the audio device is less than a 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 the open state by the open / close detection unit 90 as the fifth detection unit for detecting the opening / closing of the side window or the sunroof of the vehicle. , The frequency of the PWM signal may be lower than when the side window and the sunroof are closed. The open / close detection unit 90 can be configured to include, for example, a sensor magnet for detecting the rotational position 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 detects 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, it detects whether the vehicle is traveling on the highway based on the position information detected by the GPS device 91 and the map information provided in the vehicle.

In each of the above-described embodiments, the volume in the vehicle interior is indirectly estimated (evaluated) and the frequency of the PWM signal is switched. Therefore, it is not necessary to separately provide a means for detecting the volume in the vehicle interior, and the device is used. The number of parts can be reduced. However, the present invention is not limited to each of the above-described aspects, and the vehicle is provided with a volume detecting means for detecting the volume in the vehicle interior, and when the volume in the vehicle interior detected by the volume detecting means is equal to or higher than a predetermined value. The frequency of the PWM signal may be lower than when the volume in the room is less than a 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 the present invention is not limited to this, and the power window motor for raising and lowering the side window, and the motor used as a drive source of the 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)

The motor mounted on the vehicle and
A first switching element that can open and close between one end of the winding of the motor and the feeding end, a second switching element that can open and close between the other end of the winding of the motor and the feeding end, and a winding of the motor. A drive unit including a third switching element that can be opened and closed between one end of the wire and the grounded end, and a fourth switching element that can be opened and closed between the other end of the winding of the motor and the grounded 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.
Vehicle motor equipment including. The vehicle motor device according to claim 1, wherein the control unit lowers the frequency of the PWM signal when the volume in the vehicle interior of the vehicle is equal to or higher than a predetermined value, as compared with the case where the volume in the vehicle interior is less than a predetermined value. .. Claim 1 or 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 equal to or higher than a predetermined value, as compared with the case where the vehicle speed is less than the predetermined value. The vehicle motor device according to claim 2. When the first detection unit that detects the on / off of the air conditioner mounted on the vehicle detects the on / off of the air conditioner, the control unit has the PWM signal as compared with the case where the off of the air conditioner is detected. The vehicle motor device according to any one of claims 1 to 3, wherein the frequency of the vehicle is lowered. When the second detection unit that detects the air volume by 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 than the case where the air volume is less than the predetermined value. The vehicle motor device according to any one of claims 1 to 4, wherein the frequency of the PWM signal is lowered. The control unit has the PWM signal when the wiping speed set by the wiper switch for setting the wiping speed by the wiper device mounted on the vehicle is equal to or higher than a predetermined value, as compared with the case where the wiping speed is less than a predetermined value. The vehicle motor device according to any one of claims 1 to 5, wherein the frequency of the vehicle is lowered. One of claims 1 to 6, wherein the control unit lowers the frequency of the PWM signal when the rainfall detected by the rainfall detection unit is equal to or more than a predetermined value, as compared with the case where the rainfall is less than a predetermined value. Vehicle motor device according to the item. When the third detection unit that detects the on / off of the audio device mounted on the vehicle detects the on / off of the audio device, the control unit has the PWM signal as compared with the case where the off of the audio device is detected. The vehicle motor device according to any one of claims 1 to 7, wherein the frequency of the vehicle is lowered. When the fourth detection unit that detects the volume by the audio device mounted on the vehicle detects that the volume is equal to or higher than the predetermined value, the control unit is more likely than the case where the volume is less than the predetermined value. The vehicle motor device according to any one of claims 1 to 8, wherein the frequency of the PWM signal is lowered. The vehicle is equipped with an engine and is configured to selectively drive the engine while the 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 than when the engine is stopped. For motor equipment. The vehicle motor device according to any one of claims 1 to 10, wherein the motor is a wiper motor.

Images