JP7142534B2 - Wiper motor and control method - Google Patents

Description

The present invention relates to wiper motors and control methods.

A control wiper motor uses one temperature detection sensor, and when the temperature reaches a certain level or higher, it performs a thermal protection operation from the viewpoint of motor protection (see Patent Documents 1 and 2, for example). Here, the thermal protection operation is an operation to suppress the amount of heat generated when it is detected that the amount of heat generated by the wiper motor has increased during continuous operation under a high load (the number of times of wiping is changed from high to low. Switching to intermittent operation). etc.) to use the function to protect the motor. In the thermal protection operation, when the temperature of the motor drops, the normal wiping operation is resumed.

JP-A-2006-94590 Japanese Patent No. 5122845

However, if there is a circuit abnormality (the temperature sensor value sticks within the normal range), the failure cannot be determined, and there is a possibility that the temperature of the controller will rise and the motor will be destroyed.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a wiper motor and a control method that can use a temperature detection sensor to determine whether the motor is overheated or not. and

In one aspect of the present invention, a motor section, a gear section coupled to the motor section to reduce rotation of the motor section, a gear housing that houses the gear section, a gear housing that accommodates the gear housing, the a speed reduction mechanism section including a control section that controls rotation of the motor section, wherein the control section includes a first temperature sensor that detects a temperature of the wiper motor; and a temperature sensor that detects the temperature of the wiper motor. a second temperature sensor arranged close to the first temperature sensor; a determination unit that determines a state of exceeding a threshold or a state of less than a third threshold, which is a lower limit value of the temperature detected by at least one of the first temperature sensor and the second temperature sensor; , measuring the elapsed time since the temperature detected by at least one of the first temperature sensor and the second temperature sensor exceeds the second threshold value or becomes less than the third threshold value. The temperature detected by at least one of the first temperature sensor and the second temperature sensor is lower than the third threshold, or the first temperature sensor and A state in which the temperature detected by at least one of the second temperature sensors is higher than the second threshold, and the time measured by the abnormality determination timer exceeds a second predetermined time. and a motor rotation state changing section for changing the rotation of the motor section.

Further, in one aspect of the present invention, in the wiper motor, the rotation speed of the motor portion is made lower than the rotation speed of the motor portion when the temperature is detected by the motor rotation state changing portion. Characterized by

Further, one aspect of the present invention is the wiper motor, wherein the motor rotation state changing unit changes the motor unit to intermittent operation.
Further, one aspect of the present invention is the wiper motor described above, wherein the control unit includes a temperature difference calculation unit that calculates a temperature difference between the first temperature sensor and the second temperature sensor, and the determination a temperature difference between the first temperature sensor and the second temperature sensor that exceeds a first threshold; Elapsed time is measured from when the threshold is exceeded, and the motor rotation state changing unit determines that the temperature difference exceeds the first threshold and the time measured by the abnormality determination timer is a first predetermined time. is changed when the rotation of the motor unit is exceeded.

Further, one aspect of the present invention is the wiper motor, wherein the control unit includes a temperature difference calculation unit that calculates a temperature difference between the first temperature sensor and the second temperature sensor, and the determination unit. and a recovery judgment timer for measuring the elapsed time from when the temperature difference becomes equal to or less than a first threshold, and in a state where the time measured by the abnormality judgment timer exceeds a second predetermined time. At some point, the determination unit determines that the temperature difference between the first temperature sensor and the second temperature sensor is equal to or less than the first threshold value, and the temperature difference between the first temperature sensor and the second temperature sensor The temperature detected by both is equal to or lower than the fourth threshold, which is a temperature value that is lower than the second threshold, which is the upper limit of temperature, by a predetermined temperature, and is a temperature value that is higher than the third threshold, which is the lower limit of temperature, by a predetermined voltage. 5 threshold or more, the return determination timer measures the elapsed time after the determination unit determines that the temperature difference and the temperature are in the relevant state, and changes the motor rotation state. The part changes the rotation of the motor part when the time measured by the return determination timer exceeds a third predetermined time.

In one aspect of the present invention, the wiper motor is characterized in that the first temperature sensor and the second temperature sensor are arranged on a control board of the control unit.

In one aspect of the present invention, a motor section, a gear section coupled to the motor section to reduce rotation of the motor section, a gear housing that houses the gear section, a gear housing that accommodates the gear housing, the and a deceleration mechanism section having a control section for controlling rotation of the motor section, wherein the control section includes a first temperature sensor, and a wiper motor which is positioned close to the first temperature sensor. a second temperature sensor, a determination unit, an abnormality determination timer, and a motor rotation state changing unit; the first temperature sensor detects the temperature of the wiper motor; A temperature sensor detects the temperature of the wiper motor, and the determination unit determines a state in which the temperature detected by at least one of the first temperature sensor and the second temperature sensor exceeds a second threshold, which is an upper limit value. or a state of less than a third threshold, which is a lower limit value of the temperature detected by at least one of the first temperature sensor and the second temperature sensor, and the abnormality determination timer is controlled by the determination unit to determine the measuring the elapsed time since the temperature detected by at least one of the first temperature sensor and the second temperature sensor exceeds the second threshold value or becomes less than the third threshold value; The motor rotation state changing unit determines that the temperature detected by at least one of the first temperature sensor and the second temperature sensor is lower than the third threshold value, or the temperature detected by the determination unit is lower than the first temperature A state in which the temperature detected by at least one of the sensor and the second temperature sensor is higher than the second threshold, and the time measured by the abnormality determination timer exceeds a second predetermined time. The control method is characterized by changing the rotation of the motor unit when .
Further, one aspect of the present invention is the above control method, wherein the control unit has a temperature difference calculation unit that calculates a temperature difference between the first temperature sensor and the second temperature sensor, The determination unit determines a state in which a temperature difference between the first temperature sensor and the second temperature sensor exceeds a first threshold value, and the abnormality determination timer causes the determination unit to detect that the temperature difference has exceeded the first threshold value. 1 threshold is exceeded, and the motor rotation state changing unit determines that the temperature difference exceeds the first threshold and the time measured by the abnormality determination timer is a first predetermined time. It is characterized in that the rotation of the motor section is changed when the time is exceeded.

According to the present invention, failure determination can be performed by detecting temperatures and temperature differences between two temperature sensors, and overheat protection of the motor can be performed appropriately.

It is a mimetic diagram showing a wiper device concerning one embodiment of the present invention. 2 is a configuration diagram showing a configuration example of a brushless motor 1a shown in FIG. 1; FIG. It is a block diagram showing an outline of an example of composition of control part 12 concerning this embodiment. FIG. 10 is a diagram for explaining control for changing the rotation of the motor unit, which is performed by the motor rotation state changing unit 12c in (change condition 1); FIG. 11 is a diagram for explaining control for changing the rotation of the motor unit, which is performed by the motor rotation state changing unit 12c in (change condition 2); FIG. 12 is a diagram for explaining control for changing the rotation of the motor unit, which is performed by the motor rotation state changing unit 12c in (change condition 3);

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the overall configuration of a wiper device 10 according to one embodiment of the present invention. The wiper device 10 shown in FIG. 1 has a wiper arm 3a on the side of the driver's seat and a wiper arm 3b on the side of the passenger's seat which are swingably provided on the vehicle body. A wiper blade 4a on the driver's seat side and a wiper blade 4b on the passenger's seat side are attached to each of the wiper arms 3a and 3b. The wiper blades 4a and 4b are pressed against the windshield 300 by spring members (not shown) installed in the wiper arms 3a and 3b. The vehicle body is provided with two output shafts 9a and 9b, and the wiper arms 3a and 3b are attached at their base ends to the output shafts 9a and 9b, respectively.

The wiper device 10 is provided with two motor devices 100a and 100b for the oscillating movement of the wiper arms 3a and 3b. In the wiper device 10, the two motor devices 100a and 100b are synchronously controlled for forward and reverse rotation, so that the wiper blades 4a and 4b swing in the wiping ranges 5a and 5b indicated by dashed lines. The motor device 100a is composed of a brushless motor (hereinafter sometimes simply referred to as a motor) 1a and a speed reduction mechanism 2a. The motor device 100b is composed of a brushless motor 1b and a reduction mechanism 2b. The brushless motor 1a is connected to an ECU 200, which is a vehicle-side controller, via an in-vehicle LAN (Local Area Network) 400. FIG. Switch information such as wiper switch ON/OFF, Lo, Hi, and INT (intermittent operation), engine start information, vehicle speed information, and the like are input from the ECU 200 to the brushless motor 1a via the in-vehicle LAN 400 . A communication line 500 is connected between the brushless motors 1a and 1b. In the wiper device 10 shown in FIG. 1, the brushless motors 1a and 1b cooperate to control the operation of the wiper blades 4a and 4b by transmitting and receiving predetermined information via the communication line 500. FIG. The brushless motor 1a and the brushless motor 1b differ in part of the contents of the programs and the like, but the basic configuration can be the same.

Next, a configuration example of the brushless motor 1a shown in FIG. 1 will be described with reference to FIG. The brushless motor 1a includes an inverter 11, a control section 12, a rotor 13, a stator 14, and hall sensors 15u, 15v and 15w.

The stator 14 has a stator core (not shown) and windings 14u, 14v and 14w wound in a plurality of slots of the stator core. Windings 14u, 14v and 14w are delta-connected three-phase windings. However, not only delta connection but also star connection may be used.

The rotor 13 has permanent magnets and rotates facing the stator 14 . The rotor 13 may have an inner rotor type structure arranged inside the stator 14 or an outer rotor type structure arranged outside the stator 14 . The structures of the rotor 13 and the stator 14 are not limited. .

Hall sensors (position detectors) 15u, 15v and 15w detect the rotational position of the rotor 13 using Hall elements and output the detected results. Hall sensors 15u, 15v and 15w detect positions shifted by 120 electrical degrees. The Hall sensors 15u, 15v, and 15w are digital signals obtained by converting, for example, analog signals having magnitudes proportional to magnetic fields generated using Hall elements into high-level (H-level) or low-level (L-level) signals by means of comparators. is output to the control unit 12 . In this embodiment, the Hall sensor 15u outputs a digital signal (position detection signal Hu) corresponding to the U phase, the Hall sensor 15v outputs a digital signal (position detection signal Hv) corresponding to the V phase, and the Hall sensor 15w outputs a digital signal (position detection signal Hw) corresponding to the W phase. The Hall sensors 15u, 15v and 15w of this embodiment change the output of the inverter 11 immediately at each position where the level of the output signal of the Hall sensor 15u, 15v or 15w changes, that is, at each position where an edge occurs in the output signal. It is installed with respect to the rotor 13 so that the lead angle is 30 degrees in electrical angle.

Inverter 11 has a plurality of switching elements 11u1, 11u2, 11v1, 11v2, 11w1, and 11w2, and external power supply 600 is used as a DC power supply, and a plurality of switching elements 11u1, 11u2, 11v1, 11v2, 11w1, and 11w2 are combined in a predetermined manner. By turning on or off, an alternating current is supplied to the three-phase windings 14u, 14v and 14w. External power source 600 includes, for example, a battery, a capacitor, and the like mounted on the vehicle. In the example shown in FIG. 2, the six switching elements 11u1, 11u2, 11v1, 11v2, 11w1 and 11w2 are composed of n-channel MOSFETs (metal oxide semiconductor field effect transistors). The drains of the switching elements 11u1, 11v1 and 11w1 are commonly connected to the positive electrode of the external power supply 600 . The source of the switching element 11u1 is connected to a connection terminal (U-phase terminal) between the windings 14u and 14w and the drain of the switching element 11u2. The source of the switching element 11v1 is connected to a connection terminal (V-phase terminal) between the windings 14v and 14u and the drain of the switching element 11v2. The source of the switching element 11w1 is connected to a connection terminal (referred to as a W-phase terminal) between the windings 14w and 14v and the drain of the switching element 11w2. The sources of the switching elements 11u2, 11v2 and 11w2 are commonly connected to the negative electrode (for example, the ground terminal) of the external power supply 600 . The ON/OFF operations of the switching elements 11u1, 11u2, 11v1, 11v2, 11w1 and 11w2 are controlled by the controller 12. FIG.

The control unit 12 includes, for example, a microcomputer having a CPU (central processing unit), RAM (random access memory), ROM (read only memory), etc. and peripheral circuits thereof, and switching elements 11u1, 11u2, 11v1 and 11v2. , 11w1 and 11w2. Control unit 12 also transmits and receives predetermined information to and from ECU 200 and brushless motor 1b. In addition, the control unit 12 selects a low-speed energization pattern for low-speed energization control or a high-speed energization pattern for low-speed energization control, which indicates a change in the energization state of the windings 14u, 14v, and 14w of each phase of the three-phase winding according to the rotation of the rotor 13. The ON/OFF states of the plurality of switching elements 11u1, 11u2, 11v1, 11v2, 11w1, and 11w2 are controlled by switching to the high-speed energization pattern for control. Further, when controlling the plurality of switching elements 11u1, 11u2, 11v1, 11v2, 11w1, and 11w2 to be on or off, the control unit 12 sets the rotation speed (also referred to as motor speed) of the rotor 13 to a predetermined target value. PWM (Pulse Width Modulation) is used to control the duty ratio (also referred to as Duty output value) for each constant cycle with a predetermined limit value (also referred to as DutyLimit value). Here, the control with a predetermined limit value is a control for setting the current value flowing through the windings 14u, 14v, and 14w, and the limit value is the rotation speed of the rotor 13, the voltage value of the external power supply 600, the ambient temperature, and the like. change depending on By setting this limit value, the wiper device 10 including the motor device 100a is protected. Note that the duty ratio is a value obtained by dividing the ON time in one cycle of PWM by the total value of the ON time and the OFF time.

Here, a detailed configuration of the wiper device 10 will be described. The wiper device 10 is for wiping a windshield 300 provided in a vehicle such as a passenger car, for example. The wiper device 10 includes the above-described pair of wipers (comprised of wiper arms 3a and 3b and wiper blades 4a and 4b), brushless motors 1a and 1b (wiper motors), and controls provided by each of the brushless motors 1a and 1b. It includes a portion 12, a link mechanism (not shown in FIGS. 1 and 2), and speed reduction mechanisms 2a and 2b (speed reduction mechanism portions).
A worm is formed at the end of the rotor shaft extending from the rotor 13 in the reduction mechanism 2a (and 2b). The worm meshes with a worm wheel formed integrally with the output shaft (gear portion). In this embodiment, the worm and the worm wheel constitute the reduction mechanism 2a (and 2b). By meshing the worm and the worm wheel, the rotation of the rotor 13 can be reduced at a predetermined reduction ratio and transmitted to the output shafts 9a and 9b.
Further, the reduction mechanism 2a (and 2b) has a configuration in which a control section 12 for controlling the rotation of the motor section is provided in a gear housing that accommodates a worm wheel that reduces the rotation of the motor and an output shaft (gear section).

In the wiper device according to the present embodiment, when the pair of output shafts 9a and 9b are rotated forward and backward within a predetermined range of rotation angles, the rotational force of the output shafts is transmitted to the wiper arms 3a and 3b. and 3b reciprocate, the wiper blades 4a and 4b reciprocate between the downward reversing position and the upward reversing position on the windshield 300. As shown in FIG.

That is, the wiper device 10 includes brushless motors 1a and 1b (motor portions), output shafts (gear portions) of reduction mechanisms 2a and 2b that are coupled to the motor portions and reduce the rotation of the motor portions, and gear portions. It includes a wiper motor including a gear housing to be accommodated, and a reduction mechanism section that is accommodated in the gear housing and has a control section 12 that controls the rotation of the motor section.

Here, an example of the control unit 12 in the wiper device 10 will be described with reference to FIG. 3 . FIG. 3 is a block diagram showing an outline of an example of the configuration of the control section 12 according to this embodiment.
The control unit 12 includes a motor position estimation unit 12a, a command value calculation unit 12b, a motor rotation state change unit 12c, a first temperature sensor 12d, a second temperature sensor 12e, a temperature difference calculation unit 12f, It includes a determination unit 12g, an abnormality determination timer 12h, and a recovery determination timer 12i.
Note that the control board on which the control unit 12 is mounted has the inverter 11 shown in FIG. Further, the control board is arranged inside a gear housing that accommodates a worm wheel and an output shaft (gear portion) for decelerating the rotation of the motor.

A position detection signal Hu, a position detection signal Hv, and a position detection signal Hw, which are digital signals output by Hall sensors (position detection units) 15u, 15v, and 15w, are input to the motor position estimation unit 12a, and the position of the rotor 13 is calculated. do. The motor position estimation unit 12a outputs the calculated position of the rotor 13 to the motor rotation state change unit 12c.

Based on information input from the ECU 200 to the brushless motors 1a (and 1b), the command value calculation unit 12b selects Hi, Lo, and INT (intermittent values) for the wiper blades 4a and 4b in this order, which increases the time interval between wiping operations. ), and extracts a command signal relating to the rotation speed of the rotor 13 to set one of the three types of operation modes. The command value calculation unit 12b outputs the extracted command signal related to the rotation speed of the rotor 13 to the motor rotation state change unit 12c.

The motor rotation state changing unit 12c calculates the phase of the voltage that changes according to the position of the rotor 13 calculated by the motor position estimating unit 12a, and the calculated phase and the rotation of the rotor 13 extracted by the command value calculating unit 12b. Determine duty ratio based on speed. In addition, the motor rotation state changing unit 12c generates a PWM signal, which is a pulse signal corresponding to the duty ratio, and gates the plurality of switching elements 11u1, 11u2, 11v1, 11v2, 11w1 and 11w2 in the inverter 11 shown in FIG. PWM control is performed to output to.
In addition, the motor rotation state changing unit 12c performs control to change the rotation speed (rotation) of the brushless motor 1a (and 1b). After explaining the operation of 12h and the recovery determination timer 12i, the details will be described.

The first temperature sensor 12d and the second temperature sensor 12e are arranged close to each other on the control board of the control unit 12 . A first temperature sensor 12d and a second temperature sensor 12e detect the temperature of the brushless motor 1a (and 1b). The first temperature sensor 12d and the second temperature sensor 12e output the detected temperatures to the temperature difference calculator 12f and the determination unit 12g. It should be noted that first temperature sensor 12 d and second temperature sensor 12 e are preferably mounted near the elements forming inverter 11 . Also, if possible, a first temperature sensor 12d and a second temperature sensor 12e are implemented, for example, near windings 14u, 14v and 14w to detect overheating of brushless motor 1a (and 1b). You may

The temperature difference calculator 12f calculates a temperature difference (absolute value as a difference) between the temperature detected by the first temperature sensor 12d and the temperature detected by the second temperature sensor 12e. The temperature difference calculator 12f outputs the calculated temperature difference to the determination unit 12g.

The determination unit 12g determines whether the temperature detected by the first temperature sensor 12d and the temperature detected by the second temperature sensor 12e satisfy the following determination conditions.
(Determination Condition 1) The determination unit 12g determines whether or not the temperature difference between the first temperature sensor 12d and the second temperature sensor 12e exceeds the first threshold.
(Determination Condition 2) The determination unit 12g determines that the temperature detected by at least one of the first temperature sensor 12d and the second temperature sensor 12e exceeds the second threshold, which is the upper limit of temperature, or the lower limit of temperature. It is determined whether or not the value is less than the third threshold value.
(Determination condition 3) After the determination unit 12g determines that the state of the determination condition 2 is reached, the temperature difference between the first temperature sensor 12d and the second temperature sensor 12e becomes equal to or less than the first threshold value, and The temperature detected by both the first temperature sensor 12d and the second temperature sensor 12e is equal to or lower than a predetermined temperature value (hereinafter referred to as a fourth threshold) lower than the second threshold, which is the upper limit of the temperature, and It is determined whether or not the temperature is equal to or higher than the third threshold, which is the lower limit, by a predetermined voltage (hereinafter referred to as the fifth threshold).

The abnormality determination timer 12h and the recovery determination timer 12i are set to the elapsed time from when the determination unit 12g determines that the determination unit 12g is in the above-described (determination conditions 1) to (determination conditions 2), respectively, or the determination unit 12g measures the elapsed time from when it is determined to be "in the state" in the above (determination condition 3).
Specifically, the abnormality determination timer 12h measures the elapsed time from the time when the determination unit 12g determines that the condition is "in the state" in the above (determination conditions 1) to (determination conditions 2).
The recovery determination timer 12i measures the elapsed time from when the determination unit 12g determines that the device is in the "state" in the above (determination condition 3).

The motor rotation state changing unit 12c performs control to change the rotation of the motor unit based on the determination result of the determination unit 12g and the elapsed time measured by the abnormality determination timer 12h or the recovery determination timer 12i.
Here, the control for changing the rotation of the motor section means a command signal related to the rotation speed of the rotor 13 (three operation modes of Hi, Lo, and INT (intermittent) in which the time interval of the wiping operation becomes longer in this order). The operation mode of the motor unit (brushless motors 1a, 1b) whose operation mode is set based on the command signal set to either one) is changed from the rotation (rotation speed) according to the set operation mode. It is the control that changes.

Specifically, the motor rotation state changing unit 12c performs control to change the rotation of the motor unit based on the change conditions described below.
(Change condition 1) The motor rotation state change unit 12c determines that the determination unit 12g determines that the temperature difference between the first temperature sensor 12d and the second temperature sensor 12e exceeds the first threshold in the above (determination condition 1). When the elapsed time measured by the abnormality determination timer 12h exceeds the first predetermined time, control is performed to change the rotation of the motor unit.
(Change condition 2) The motor rotation state change unit 12c determines that the determination unit 12g determines in the above (determination condition 2) that the temperature detected by at least one of the first temperature sensor 12d and the second temperature sensor 12e is The second threshold, which is the upper limit of the temperature, is exceeded, or the temperature is less than the third threshold, which is the lower limit of the temperature." When the time is exceeded, control is performed to change the rotation of the motor section. Note that the modification condition 2 may include the modification condition 1 .
(Change condition 3) The motor rotation state change unit 12c determines that the determination unit 12g in the above (determination condition 3) “after determining that the state of the determination condition 2 has been reached, the first temperature sensor 12d and the second temperature sensor 12d The temperature difference with the temperature sensor 12e is equal to or less than the first threshold, and the temperatures detected by both the first temperature sensor 12d and the second temperature sensor 12e are equal to or less than the fourth threshold and equal to or greater than the fifth threshold. When the elapsed time measured by the recovery determination timer 12i exceeds the third predetermined time, control is performed to change the rotation of the motor unit.

More specifically, the motor rotation state changing unit 12c lowers the rotation speed of the motor units (brushless motors 1a and 1b) at the time when the temperature difference calculation unit 12f detects the temperature difference. , the rotational speed of the motor unit is reduced (the time interval between wiping operations is lengthened).
Alternatively, the motor rotation state changing unit 12c performs control to change the operation mode set to one of two types of operation modes, for example Hi and Lo, to INT (intermittent) operation.
Next, with reference to FIGS. 4 to 6, the control for changing the rotation of the motor section performed by the motor rotation state changing section 12c under the above-described (change conditions 1) to (change conditions 3) will be described.

FIG. 4 is a diagram for explaining the control for changing the rotation of the motor section performed by the motor rotation state changing section 12c in (change condition 1).
In FIG. 4, changes in time (Time) of temperatures detected by temperature sensor 1 (first temperature sensor 12d) and temperature sensor 2 (second temperature sensor 12e), measurement of abnormality determination timer (abnormality determination timer 12h) It shows the time change of time.
In order to indicate the time at which the wiper operation switches from the Hi or (or) Lo operation mode to the INT (intermittent) operation, a signal indicated by "temperature detection circuit abnormality" is considered for convenience, and the signal is L (Low ) level to H (High) level, the motor rotation state changing unit 12c changes the rotation of the motor unit.
In FIG. 4, at time t11, the determination unit 12g determines whether the temperature difference between the first temperature sensor 12d and the second temperature sensor 12e exceeds the first threshold value (30° C.). do. This determination result is a determination result that exceeds.
The abnormality determination timer 12h measures the elapsed time from the time when the determination unit 12g determines that "exceeds" in (determination condition 1). However, at time t12, the determination unit 12g determines that (determination condition 1) is "not exceeded", so the abnormality determination timer 12h resets the elapsed time to 0 ms (milliseconds).
The reason why the determination unit 12g determines that "not exceeded" in (determination condition 1) is that the temperature detected by the first temperature sensor 12d varies as shown in the figure, and the temperature difference is the first The reason for this is that the temperature is below the 1 threshold value (30° C.).
At time t13, as shown in the figure, the temperature difference detected by the first temperature sensor 12d has disappeared, so the temperature difference exceeds the first threshold value (30° C.), and the abnormality determination timer 12h determines that the determination unit 12g (determination condition In 1), measure again the elapsed time from the time when it is determined to be "exceeded".

At time t14, when the elapsed time measured by the abnormality determination timer 12h exceeds the first predetermined time (1008 ms), the motor rotation state changing unit 12c changes the rotation of the motor unit from Hi or Lo operation to INT ( control to change to intermittent) operation.
The second threshold (160° C.), which is the upper limit, and the third threshold (−50° C.), which is the lower limit, shown in FIG.
That is, the normal temperature value detectable by the temperature sensor is represented by the normal value range of second threshold≧temperature value≧third threshold. On the other hand, an abnormal temperature that can be detected by the temperature sensor is represented by an abnormal value range of second threshold<temperature or temperature<third threshold.
As described above, in the brushless motors 1a and 1b (wiper motors) of the present embodiment, even if there is a circuit abnormality (temperature sensor value sticks within the normal value range), it is possible to make a failure judgment, and the controller (control unit 12 Also, there is an effect that the possibility of the motor being destroyed by the temperature rise of the inverter 11) can be reduced. That is, by detecting the temperature and the temperature difference between the two temperature sensors, it is possible to determine the failure and appropriately protect the motor from overheating.

FIG. 5 is a diagram for explaining the control for changing the rotation of the motor section performed by the motor rotation state changing section 12c in (change condition 2).
In FIG. 5, changes in time (Time) of temperatures detected by temperature sensor 1 (first temperature sensor 12d) and temperature sensor 2 (second temperature sensor 12e) and measurement of an abnormality determination timer (abnormality determination timer 12h) It shows the time change of time.
In order to indicate the time at which the wiper operation switches from the Hi or (or) Lo operation mode to the INT (intermittent) operation, a signal indicated by "temperature detection circuit abnormality" is considered for convenience, and the signal is L (Low ) level to H (High) level, the motor rotation state changing unit 12c changes the rotation of the motor unit.
In FIG. 5, at time t21, the temperature detected by the first temperature sensor 12d begins to rise, and at time t22, the determination unit 12g sets the second threshold value (160 °C) is exceeded. This determination result is a determination result that exceeds.

The abnormality determination timer 12h measures the elapsed time from the time when the determination unit 12g determines that (determination condition 2) is "exceeded" at time t22. Note that the determination unit 12g may perform the determination indicated by (determination condition 1) between times t21 and t22.
Then, at time t23, when the elapsed time measured by the abnormality determination timer 12h exceeds the second predetermined time (108 ms), the motor rotation state changing unit 12c changes the rotation of the motor unit from Hi or Lo operation to INT ( control to change to intermittent) operation.

FIG. 6 is a diagram for explaining the control for changing the rotation of the motor section performed by the motor rotation state changing section 12c in (change condition 3).
In FIG. 6, changes in time (Time) of temperatures detected by temperature sensor 1 (first temperature sensor 12d) and temperature sensor 2 (second temperature sensor 12e), abnormality determination timer (abnormality determination timer 12h), and recovery It shows the time change of the measurement time of the determination timer (recovery determination timer 12i).
Also, as the wiper operation, in order to indicate the time at which the operation mode of Hi or (or) Lo is switched to INT (intermittent) operation, or the time at which the operation mode of INT (intermittent) operation is switched to Hi or (or) Lo operation, Considering for convenience the signal indicated by "temperature detection circuit abnormality", at the time when the signal switches from L (Low) level to H (High) level or from H level to L level, the motor rotation state changing unit 12c is supposed to change the rotation of the motor part.
In FIG. 6, at time t31, the temperature detected by the first temperature sensor 12d begins to rise, and at time t32, the determination unit 12g sets the second threshold value (160 °C) is exceeded. This determination result is a determination result that exceeds.

The abnormality determination timer 12h measures the elapsed time from the time when the determining unit 12g determines that (determination condition 2) is "exceeded" at time t32.
Then, at time t33, when the elapsed time measured by the abnormality determination timer 12h exceeds the second predetermined time (108 ms), the motor rotation state changing unit 12c changes the rotation of the motor unit from Hi or Lo operation to INT ( control to change to intermittent) operation.
The above operation is the same as the operation in (change condition 2) shown in FIG. is.

In FIG. 6, between times t33 and t34, the temperature detected by the first temperature sensor 12d begins to decrease. 12e (calculation result of the temperature difference calculation unit 12f) is equal to or less than the first threshold value (30° C.), and the temperature detected by both the first temperature sensor 12d (and the second temperature sensor 12e) is below the fourth threshold (140 ms) and above the fifth threshold (-30° C.). This determination result is a determination result indicating that such a state exists.
In addition, the recovery determination timer 12i measures the elapsed time from when the determining unit 12g determined that "it is in such a state" in (determination condition 3) at time t34. The abnormality determination timer 12h resets the elapsed time from the second predetermined time (108 ms) to 0 ms.
Then, at time t34, when the elapsed time measured by the return determination timer 12i exceeds the third predetermined time (108 ms), the motor rotation state changing unit 12c changes the rotation of the motor unit from INT (intermittent) operation to Hi. Or control to change to Lo operation.
The fourth threshold (140° C.) shown in FIG. 6 and the fifth threshold (−30° C.) not shown in FIG. 160° C.), which is a predetermined temperature value lower or higher than the third threshold value (-50° C.) which is the lower limit.
That is, the normal temperature value detectable by the temperature sensor is represented by the normal value range of second threshold>fourth threshold≧temperature value≧fifth threshold>third threshold.
As described above, in the brushless motors 1a and 1b (wiper motors) of the present embodiment, even if there is a circuit abnormality (temperature sensor value sticks within the normal value range), it is possible to make a failure judgment, and the controller (control unit 12 Also, there is an effect that the possibility of the motor being destroyed by the temperature rise of the inverter 11) can be reduced.

As described above, according to the embodiment of the present invention, it is possible to detect the temperature and the temperature difference between the two temperature sensors to perform failure determination and appropriately protect the motor from overheating.

In addition, embodiment of this invention is not limited to the above. For example, in the above-described embodiment, the rotor 13 and stator 14, the inverter 11 and the control unit 12 are integrally configured. and the inverter 11 may be configured separately from other components. In the above-described embodiment, the wiper device 10 is provided with the two motor devices 100a and 100b. However, the present invention is not limited to this configuration. 3b may be configured to swing. Also, in the above embodiment, the brushless motors 1a and 1b are used as components of the wiper device 10, but the field of application is not limited to the wiper device.

1a, 1b brushless motor 10 wiper devices 100a, 100b motor device 11 inverters 11u1, 11u2, 11v1, 11v2, 11w1, 11w2 switching element 12 control unit 12a motor position estimation unit 12b command value calculation unit 12c motor rotation state change unit 12d first temperature sensor 12e, second temperature sensor 12f, temperature difference calculator 12g, determination unit 12g
12h Abnormality determination timer 12i Recovery determination timer 13 Rotor 14 Stator 14u, 14v, 14w Windings 15u, 15v, 15w Hall sensor

Claims (8)

a motor section;
A speed reducer comprising: a gear unit that is coupled to the motor unit to reduce rotation of the motor unit; a gear housing that stores the gear unit; and a control unit that is housed in the gear housing and controls rotation of the motor unit. a mechanical part;
A wiper motor comprising
The control unit
a first temperature sensor that detects the temperature of the wiper motor;
a second temperature sensor that senses the temperature of the wiper motor and is positioned proximate to the first temperature sensor;
A state in which the temperature detected by at least one of the first temperature sensor and the second temperature sensor exceeds a second threshold, or at least of the first temperature sensor and the second temperature sensor a determination unit that determines a state of less than a third threshold, which is the lower limit value of the temperature detected by one;
From when the temperature detected by at least one of the first temperature sensor and the second temperature sensor exceeds the second threshold value or becomes less than the third threshold value by the determination unit an abnormality determination timer that measures the elapsed time;
The temperature detected by at least one of the first temperature sensor and the second temperature sensor by the determination unit is lower than the third threshold value, or the temperature detected by the first temperature sensor and the second temperature sensor is higher than the second threshold, and the time measured by the abnormality determination timer exceeds a second predetermined time, the motor unit a motor rotation state changing unit that changes the rotation of the
A wiper motor comprising: The wiper motor according to claim 1, wherein the motor rotation state changing unit lowers the number of rotations of the motor section below the number of rotations of the motor section when the temperature is detected. The wiper motor according to claim 1, wherein the motor rotation state changing portion changes the motor portion to intermittent operation. The control unit
a temperature difference calculator that calculates a temperature difference between the first temperature sensor and the second temperature sensor;
The determination unit determines a state in which a temperature difference between the first temperature sensor and the second temperature sensor exceeds a first threshold,
The abnormality determination timer measures the elapsed time from when the temperature difference exceeds the first threshold by the determination unit,
The motor rotation state changing section changes the rotation of the motor section when the temperature difference exceeds the first threshold and the time measured by the abnormality determination timer exceeds a first predetermined time.
The wiper motor according to any one of claims 1 to 3, characterized in that: The control unit
a temperature difference calculator that calculates a temperature difference between the first temperature sensor and the second temperature sensor;
a recovery determination timer that measures the elapsed time from when the temperature difference becomes equal to or less than a first threshold by the determination unit;
when the time measured by the abnormality determination timer exceeds a second predetermined time,
The determination unit determines that the temperature difference between the first temperature sensor and the second temperature sensor is equal to or less than the first threshold value, and both the first temperature sensor and the second temperature sensor detect The temperature is equal to or less than a fourth threshold, which is a temperature value lower than the second threshold, which is the upper limit of temperature, by a predetermined temperature, and is equal to or higher than a fifth threshold, which is a temperature value higher than the third threshold, which is the lower limit of temperature, by a predetermined voltage. determine that it is in a state of
The recovery determination timer measures the elapsed time after the determination unit determines that the temperature difference and the temperature are in the relevant state,
The motor rotation state changing unit changes the rotation of the motor unit when the time measured by the return determination timer exceeds a third predetermined time. 5. A wiper motor according to any one of claims 4 to 5. The first temperature sensor and the second temperature sensor are
The wiper motor according to any one of claims 1 to 5, wherein the wiper motor is arranged on a control board of the control unit. a motor section;
A speed reducer comprising: a gear unit that is coupled to the motor unit to reduce rotation of the motor unit; a gear housing that stores the gear unit; and a control unit that is housed in the gear housing and controls rotation of the motor unit. a mechanical part;
A wiper motor control method comprising
The control unit has a first temperature sensor, a second temperature sensor arranged close to the first temperature sensor, a determination unit, an abnormality determination timer, and a motor rotation state change unit. death,
The first temperature sensor detects the temperature of the wiper motor,
The second temperature sensor detects the temperature of the wiper motor,
The determination unit determines a state in which the temperature detected by at least one of the first temperature sensor and the second temperature sensor exceeds a second threshold value, or a state in which the temperature detected by the first temperature sensor and the second temperature sensor exceeds a second threshold value. Determine the state of less than the third threshold, which is the lower limit of the temperature detected by at least one of the temperature sensors,
The abnormality determination timer starts when the temperature detected by at least one of the first temperature sensor and the second temperature sensor exceeds the second threshold value or is less than the third threshold value. Measure the elapsed time from when it becomes
The motor rotation state changing unit determines that the temperature detected by at least one of the first temperature sensor and the second temperature sensor is lower than the third threshold value, or the temperature detected by the determination unit is lower than the first temperature A state in which the temperature detected by at least one of the sensor and the second temperature sensor is higher than the second threshold, and the time measured by the abnormality determination timer exceeds a second predetermined time. A control method characterized by changing the rotation of the motor section when . The control unit
a temperature difference calculator that calculates a temperature difference between the first temperature sensor and the second temperature sensor;
The determination unit determines a state in which a temperature difference between the first temperature sensor and the second temperature sensor exceeds a first threshold,
The abnormality determination timer measures the elapsed time from when the temperature difference exceeds the first threshold by the determination unit,
The motor rotation state changing section changes the rotation of the motor section when the temperature difference exceeds the first threshold and the time measured by the abnormality determination timer exceeds a first predetermined time.
8. The control method according to claim 7, characterized by:

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