JP6992474B2 - Electronic control device - Google Patents

Description

The present invention relates to an electronic control device that drives a motor mounted on a vehicle.

Motors mounted on vehicles may be exposed to water depending on where they are mounted. In particular, in cold regions, the attached moisture may freeze and the motor may be locked. When the motor is locked, excessive current flows and heat is generated, which causes the motor to deteriorate or be damaged. Therefore, when the motor freezes and reaches a locked state, it is conceivable to warm up the motor to eliminate the frozen state. For example, Patent Document 1 discloses a technique for warming a motor by induction heating by passing a current about twice as much as usual through the winding of the motor.

Japanese Unexamined Patent Publication No. 2014-230434

However, it is assumed that it will take a considerable amount of time to eliminate the frozen state of the motor by applying the technique of Patent Document 1. Further, when the outside air temperature is low, the moisture thawed by heating may freeze again, resulting in poor efficiency.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electronic control device capable of eliminating a frozen state of a motor in a shorter time.

According to the electronic control device according to claim 1, when the lock detection unit detects that the motor mounted on the vehicle is locked, the control unit transfers an alternating current to the winding by a drive circuit to energize the motor. Is induced and heated, and torque is generated to vibrate the motor to release the freeze lock. With this configuration, in addition to inducing heating the motor, the motor can be vibrated to efficiently eliminate the locked state due to freezing in a shorter time.
Further, a frequency changing unit for changing the frequency of the alternating current and a temperature detecting unit for detecting the temperature or temperature of the motor are provided, and the control unit is capable of detecting the alternating current if the temperature detected by the temperature detecting unit is equal to or less than the threshold value. The freeze lock release process is performed without changing the frequency within the control cycle, and when the temperature exceeds the threshold value, the foreign matter removal process is performed to change the frequency of the alternating current according to the temperature detected within the control cycle.

According to the electronic control device according to claim 5 , a capacitor connected between the winding terminals of the motor is provided, and the control unit energizes an alternating current by LC resonance. For example, in a motor having a small allowable current amount, it cannot be expected to increase the calorific value by increasing the energizing current amount. Therefore, by connecting a capacitor and energizing a high frequency current due to LC resonance, heating can be performed more efficiently. In addition, the amount of heating can be adjusted by the capacity of the capacitor.

According to the electronic control device according to claim 6 , the capacitance of the capacitor is set so that the frequency of LC resonance does not match the harmonic component of the drive frequency of the motor. This makes it possible to avoid induction heating when driving the motor.

According to the electronic control device according to claim 7 , a switch is provided between the winding terminal of the motor and the capacitor, and the control unit turns on the switch when the alternating current for heating is applied. This makes it possible to avoid induction heating by turning off the switch when driving the motor, without considering the relationship between the drive frequency of the motor and the LC resonance frequency.

The figure which is 1st Embodiment and shows the structure of an ECU. A flowchart showing the freeze lock release process performed by the control circuit. The figure which shows the switching pattern of each phase arm of the inverter circuit in the warm-up mode and the normal drive of a motor. Cross-sectional view showing the structure of the motor The figure explaining the state which heat generated by induction heating is conducted and reaches ice. The figure which is 2nd Embodiment and shows the structure of an ECU. The figure which shows the relationship between the on / off setting of switches SW1 to SW3 and the resonance frequency in each mode. The figure which shows the change between the motor temperature and the circuit temperature when the resonance frequency is constant. The figure which shows the change between the motor temperature and the circuit temperature when the resonance frequency can be changed. A flowchart which is the third embodiment and shows a process in which a control circuit executes a warm-up mode and a foreign matter removal mode separately. A flowchart showing the execution contents of the warm-up mode Diagram explaining the definition of each temperature Flow chart showing the execution contents of the foreign matter removal mode FIG. 4 is a diagram showing a configuration of an ECU according to a fourth embodiment. Diagram showing different noise regulation patterns for each destination of the vehicle

(First Embodiment)

As shown in FIG. 1, the ECU 1 which is an electronic control device includes a control circuit 2, a temperature detection circuit 3, and an inverter circuit 4. The inverter circuit 4 corresponding to the drive circuit is configured by connecting six switching elements, for example, an N-channel MOSFET, with a three-phase bridge. The codes of the six FETs are Tr1 to Tr6. The inverter circuit 4 drives the motor 5 mounted on the vehicle. The motor 5 is, for example, a fan motor that blows air.

A vehicle battery 6 is connected between the positive and negative power lines of the inverter circuit 4. The motor 5 includes stator windings L1 to L3 that are delta-connected, and the U, V, and W phase output terminals of the inverter circuit 4 are connected to the winding terminals T1 to T3 of the motor 5. A capacitor C3 is connected between the terminals T1 and T2, a capacitor C1 is connected between the terminals T2 and T3, and a capacitor C2 is connected between the terminals T1 and T3.

The control circuit 2 corresponding to the control unit outputs a PWM signal as a drive signal to the gates of each FET_Tr1 to Tr6 constituting the inverter circuit 4. The temperature detection circuit 3 corresponding to the temperature detection unit is composed of, for example, a thermistor or the like, and detects the outside air temperature or the temperature of the motor 5. The detection signal is input to the control circuit 2. Further, the ECU 1 includes a motor lock detection unit 7. The motor lock detection unit 7 is, for example, a shunt resistance or current sensor that detects the energization current of the motor 5, a position sensor that detects the rotational state of the motor 5, or the like. Then, the control circuit 2 detects the energization current and the rotational state of the motor 5 by the motor lock detection unit 7, and determines that the motor 5 is in the locked state.

As shown in FIG. 4, the motor 5 is, for example, an outer rotor type. The module of the inverter circuit 4 is mounted on the upper surface side of the circuit board 11 in the drawing, and the motor 5 is mounted on the lower surface side of the circuit board 11. The end of the winding L is connected to the circuit board 11 via the housing 12 of the motor 5. The winding L is wound around the stator core 13 via the insulator 14. The stator core 13 is fixed to the housing 12 by screws 15. A shaft 16 is attached downward from the center of the housing 12. The upper end of the shaft 16 is fixed to the housing 12.

The rotor 17 has a bottomed cylindrical shape with an open upper portion, and a hole 18 for inserting the shaft 16 is formed in the central portion thereof. The rotor 17 is rotatably supported by the shaft 16 via a bearing 19. A rotor magnet 20 is arranged on the inner peripheral surface of the rotor 17 so as to face the side surface of the stator core 13.

Next, the operation of this embodiment will be described. As shown in FIG. 2, the control circuit 2 determines whether or not the motor 5 is in the locked state when the motor 5 is started (S1). That is, even if the windings L1 to L3 are energized via the inverter circuit 4 so as to rotate the motor 5, the motor 5 is locked when the motor 5 does not rotate or the energization current amount increases excessively. It can be judged that it is in a state. If the motor 5 is not in the locked state (NO), the motor 5 is driven as it is and normal control is started (S5).

On the other hand, if the motor 5 is in the locked state (S1; YES), it can be estimated that the motor 5 is locked due to freezing, as shown in FIG. 5, by referring to the outside air temperature or the temperature of the motor 5 at that time. Then, in order to release the freeze lock, the control circuit 2 induces and heats the motor 5 and causes the motor 5 to vibrate (S2). At this time, the capacitors C1 to C3 are connected in parallel to the windings L1 to L3 to generate an alternating current due to LC resonance.

In step S2, as shown in FIG. 3, the windings L1 to L3 are energized in the warm-up mode. In the warm-up mode, the portion of the stator core 13 around which the windings L1, L2, and L3 are wound is switched to be individually induced and heated. When heating the core 13 portion corresponding to the winding L1, the FET_Tr3 on the upper side of the V phase and the FET_Tr6 on the lower side of the W phase are switched. The switching frequency should match the LC resonance frequency. As a result, a resonance current is applied to the winding L1 connected between the terminals T2 and T3 to heat the corresponding core 13 portion. Further, the LC time constant is adjusted so that the resonance frequency does not match the harmonic frequency having the frequency when driving the motor 5 as the fundamental wave. The warm-up mode corresponds to the freezing lock release process.

As shown in FIG. 5, the heat generated by the induction heating of the stator core 13 is conducted through the housing 14 to heat and melt the ice. Further, by energizing the winding L1 with an alternating current, torque is generated so that the rotor 17 vibrates. By adding vibration in this way, the freeze lock is eliminated. Similarly, when the core 13 portion corresponding to the winding L2 is heated and vibration is generated, the FET_Tr5 on the upper side of the W phase and the FET_Tr2 on the lower side of the U phase are switched. Further, when the core 13 portion corresponding to the winding L3 is heated and vibration is generated, the FET_Tr1 on the upper side of the U phase and the FET_Tr4 on the lower side of the V phase are switched.

See FIG. 2 again. In step S2, after energizing in the warm-up mode for a predetermined time, it is determined again whether or not the motor 5 is in the locked state (S3). Here, if the freezing lock is released, the process proceeds to (NO) step S5. On the other hand, if the locked state of the motor 5 is not released (YES), the motor 5 is not locked due to freezing, but the locked state that cannot be easily released, for example, due to the biting of a foreign substance, or the disconnection, etc. Occurrence is expected. Therefore, a diagnostic signal is output to the outside to notify the user to that effect (S4).

As described above, according to the present embodiment, when the lock detection unit 7 detects that the motor 5 mounted on the vehicle is locked, the control circuit 2 constituting the ECU 1 is wound L1 to the winding L1 by the inverter circuit 4. By energizing L3 with an alternating current, the motor 5 is induced and heated, and torque is generated so as to vibrate the motor 5 to perform the freeze lock release process. With this configuration, the locked state due to freezing can be efficiently eliminated in a shorter time by vibrating the motor 5 in addition to induction heating.

The capacitors C1 to C3 connected between the winding terminals T1 to T3 of the motor 5 are provided, and the control circuit 2 energizes an alternating current due to LC resonance. As a result, even when the allowable current amount of the motor 5 is small, heating can be performed more efficiently by energizing a high frequency current due to LC resonance. Further, the amount of heating can be adjusted by the capacity of the capacitors C1 to C3.

Further, by setting the capacitances of the capacitors C1 to C3 so that the LC resonance frequency does not match the harmonic component of the drive frequency of the motor 5, it is possible to avoid induction heating when the motor 5 is driven. It is possible to prevent the efficiency from decreasing and the deterioration of the motor 5 from progressing.

Further, the control circuit 2 switches the windings L1 to L3 at predetermined time intervals to energize the alternating current. As a result, the stator core 13 can be heated uniformly and evenly, and the freeze lock can be efficiently eliminated.

In addition, the control circuit 2 outputs a diagnostic signal for notifying the user to the outside if the 5 freeze lock of the motor is not released even after the freeze lock release process is executed for a predetermined time. In this case, it is possible to notify the user that the motor 5 is in a locked state that cannot be easily resolved, such as due to the biting of a foreign substance, and have the service center take measures such as taking action.
(Second Embodiment)

Hereinafter, the same parts as those in the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and different parts will be described. As shown in FIG. 6, in the ECU 21 of the second embodiment, the switch SW1 is inserted between the terminal T2 and the capacitor C1. Similarly, switches SW2 and SW3 are inserted between the terminals T1 and the capacitors C2 and C3, respectively. The on / off control of these switches SW1 to SW3 is performed by the control circuit 22. The control circuit 22 corresponds to a frequency changing unit.

Next, the operation of the second embodiment will be described. The control circuit 22 turns on the switches SW1 to SW3 when the motor 5 is energized in the warm-up mode, and turns off when the motor 5 is driven in the normal control. As a result, as in the first embodiment, induction heating is not performed when the motor 5 is driven, even if the relationship between the LC resonance frequency and the harmonic frequency of the drive frequency is not particularly considered.

Further, by providing the switches SW1 to SW3, it becomes possible to change the resonance frequency. Here, the inductance of the windings L1 to L3 is L, and the capacitances of the capacitors C1 to C3 are all C. For example, as shown in FIG. 7, when only the switch SW2 is turned on when heating the core 13 portion corresponding to the winding L2, the resonance frequency becomes 1 / {2π√ (LC)}. This is referred to as "intermediate frequency mode".

Further, when the switches SW1 and SW3 are turned on, the resonance frequency becomes 1 / {2π√ (LC / 2)}, which is higher than that in the “intermediate frequency mode”. This is referred to as "high frequency mode". Then, when all of the switches SW1 to SW3 are turned on, the resonance frequency becomes 1 / {2π√ (3LC / 2)}, which is lower than the "intermediate frequency mode". This is referred to as "low frequency mode". In this way, the resonance frequency can be changed. The amount of heat generated increases as the resonance frequency increases.

As shown in FIG. 8, if the resonance frequency is constant, in the warm-up mode, only the induction heating is performed at that frequency, and it is necessary to stop the induction heating before the superheat threshold is reached. Therefore, even if the heating temperature is controlled to be constant to some extent, there is no choice but to perform induction heating intermittently. In this case, the temperature of the circuit having a small heat capacity repeats a rapid rise and fall. Then, the solder used for connecting the circuit elements is strongly affected by the thermal cycle, which causes the life to be shortened.

On the other hand, if the heating amount can be adjusted by switching the resonance frequency as in the second embodiment, the warm-up mode can be continued while adjusting as shown in FIG. In this case, since the change width of the heat applied to the circuit is also small, it is possible to prevent the solder life from being shortened. The target temperature in the warm-up mode is set to, for example, about “(superheat threshold value) −5 ° C.”.

As described above, according to the second embodiment, switches SW1 to SW3 are provided between the winding terminals T1 and T2 of the motor 5 and the capacitors C1 to C3, and the control circuit 22 energizes an alternating current for heating. At that time, the switches SW1 to SW3 are turned on. As a result, even if the relationship between the drive frequency of the motor 5 and the LC resonance frequency is not taken into consideration, if the switches SW1 to SW3 are turned off when the motor 5 is driven, induction heating can be avoided.

Further, since the control circuit 22 changes the LC resonance frequency by changing the combination of turning on the switches SW1 to SW3, the warm-up mode can be continued while changing the heating amount.
(Third Embodiment)

In the third embodiment, the same configuration as in the second embodiment is adopted, and a "warm-up mode" for releasing the freezing lock according to the detected temperature and a "foreign matter removing mode" for removing the foreign matter caught by the motor 5. ”And separately. As shown in FIG. 10, after initializing the counter n for counting the number of times the locked state is detected (S11), it is determined whether or not the motor 5 is in the locked state (S12). If it is in the locked state (YES), the detection counter n is incremented (S13), and it is determined whether or not the temperature detected at that time is equal to or less than the specified value corresponding to the threshold value (S14).

If the temperature is equal to or lower than the specified value in step S14 (YES), it is presumed that the motor lock at that time is due to freezing, and the "warm-up mode" is executed (S15). On the other hand, if the temperature exceeds the specified value (NO), it is presumed that the motor lock is not due to freezing but due to the biting of foreign matter, and the "foreign matter removal mode" is executed (S16).

After the execution of steps S15 and S16, it is determined whether or not the value of the detection counter n has reached the predetermined value nset (S17), and if the value has not reached the predetermined value nset (NO), the process returns to step S12. If the predetermined value nset is reached (YES), it is determined that the motor lock is not released even by executing the "warm-up mode" or the "foreign matter removal mode", and the diagnostic output is performed (S18).

In the "warm-up mode", as shown in FIG. 11, first, a "warm-up timer" for measuring the execution time is started (S21). Then, the residual temperature ΔT and the convergence test temperature are compared (S22). Here, the “residual ΔT” is the difference between the target temperature Tref in the warm-up mode and the current detected temperature Treal, as shown in FIG. Further, as shown in the figure, the "convergence determination temperature" is two types of temperatures Tconv1 and Tconv2 set based on the warm-up target temperature Tref.
It is set to (Tconv1> Tconv2). In step S22, four branches are made to steps S23 to S26 according to the temperature comparison result.

If the residual ΔT is the convergence test temperature Tconv1 or higher, the “high frequency mode” shown in the second embodiment is executed (S23). If the residual ΔT is less than the convergence test temperature Tconv1 and Tconv2 or more, the “intermediate frequency mode” is executed (S24). If the residual ΔT is less than the convergence test temperature Tconv2 and is “0” or more, the “low frequency mode” is executed (S25). That is, the amount of heating in the warm-up mode is changed according to the width of the residual ΔT. If the residual ΔT is less than “0”, the heating is sufficiently stopped, and the warm-up is temporarily stopped (S26).

Then, it is determined whether or not the "warm-up timer" has reached the operation time of the preset warm-up mode (S27), and if the operation time has not been reached, the process returns to step S22 (NO). If the operation time is reached (YES), the warm-up mode is terminated. The period from the "warm-up timer start" in step S21 to the determination of "YES" in the "warm-up timer end" in step S27 corresponds to the control cycle.

On the other hand, in the "foreign matter removal mode" corresponding to the foreign matter removal process, as shown in FIG. 13, the current detection temperature Treal and the environmental temperature set value are first compared (S31). Here, the "environmental temperature set value" is two types of temperatures Tset1 and Tset2, and is set to (Tset <Tset2). In step S31, there are three branches to steps S32, S35, and S37 according to the temperature comparison result.

When the detection temperature Treal is less than the set value Tset1 and is relatively low, the "high frequency mode" (S32), the "intermediate frequency mode" (S33), and the "low frequency mode" (S34) are sequentially executed for a predetermined time. As a result, the frequency of vibration is changed to remove foreign matter. If the detection temperature Treal is equal to or greater than the set value Tset1 and less than the set value Tset2, the "intermediate frequency mode" (S35) and the "low frequency mode" (S36) are sequentially executed for predetermined times. When the detected temperature Treal is equal to or higher than the set value Tset2 and is relatively high, only the "low frequency mode" is executed to prevent the motor 5 from becoming overheated (S37), and vibration is generated.
In both the "warm-up mode" and the "foreign matter removal mode", the period from "start" to "end" corresponds to the control cycle.

As described above, according to the third embodiment, if the temperature detected by the temperature detection circuit 3 is equal to or less than the specified value, the control circuit 22 "warms up" without changing the frequency of the alternating current within the control cycle. When the temperature exceeds the specified value, the "mode" is executed, and the "foreign matter removal mode" is executed in which the frequency of the alternating current is changed according to the temperature detected in the control cycle. This makes it possible to handle both cases of freezing lock and locking due to the biting of foreign matter or the like.

Further, the control circuit 22 is in the “high frequency mode” according to the magnitude of the difference ΔT between the temperature Treal detected by the temperature detection circuit 3 and the target temperature Tref for induction heating when the “warm-up mode” is executed. , "Intermediate frequency mode" and "Low frequency mode" are executed separately. As a result, the motor 5 can be heated without exceeding the overheat protection threshold value.

Further, when the control circuit 22 executes the "foreign matter removal mode", the control circuit 22 executes only the "low frequency mode" or also executes the "high frequency mode" and the "intermediate frequency mode" according to the detection temperature Treal. I tried to decide whether to do it. As a result, when the detection temperature Treal is relatively high, it is possible to generate vibration and remove foreign matter while avoiding the motor 5 from becoming overheated.
(Fourth Embodiment)

As shown in FIG. 14, the ECU 31 of the fourth embodiment includes an operation switch 32 for the user to switch on / off of the switches SW1 to SW3 of the second embodiment from the outside. The operation switch 32 is arranged so that, for example, the operator can be operated from outside the housing of the ECU 31. The operation switch 32 may directly and mechanically switch the on / off of the switches SW1 to SW3. Further, the control circuit 22 reads the high and low binary levels according to the setting of the operation switch 32 via the input port, and sets the on / off of the switches SW1 to SW3 by software processing as in the second embodiment. Is also good.

With this configuration, for example, as shown in FIG. 15, even if the band that regulates noise differs depending on the destination of the vehicle as in patterns A and B, the user operates the operation switch 32 for induction heating and It is possible to switch the AC frequency for adding vibration. For example, in the case of the noise regulation pattern A, since the band corresponding to the "low frequency mode" is restricted, it corresponds by switching to the "intermediate frequency mode" or the "high frequency mode". Further, in the case of the noise regulation pattern B, since the band corresponding to the "intermediate frequency mode" is restricted, it is sufficient to switch to the "low frequency mode" or the "high frequency mode".

As described above, according to the fourth embodiment, since the switch 32 that can be operated from the outside is provided in order to change the LC resonance frequency, the user can respond so as to clear the noise regulation for each destination of the vehicle.

(Other embodiments)
In the second to fourth embodiments, four or more sets of capacitors and switches may be provided, and the resonance frequency may be changed by four or more steps.
It may be applied to an in-vehicle motor other than a fan motor.
The present disclosure has been described in accordance with the examples, but it is understood that the present disclosure is not limited to the examples and structures. The present disclosure also includes various variations and variations within a uniform range. In addition, various combinations and forms, as well as other combinations and forms that include only one element, more, or less, are within the scope and scope of the present disclosure.

In the drawings, 1 is an ECU, 2 is a control circuit, 3 is a temperature detection circuit, 4 is an inverter circuit, 5 is a motor, and 7 is a motor lock detection unit.

Claims (10)

A drive circuit (4) that energizes the windings (L1, L2, L3) of the motor ( 5 ) mounted on the vehicle, and
A lock detection unit (7) that detects the locked state of the motor, and
When it is detected that the motor is locked, the drive circuit energizes the winding to induce and heat the motor, and at the same time, a torque is generated to vibrate the motor to release the freeze lock. The control unit (2, 22, 32) that performs processing, and
A frequency changing unit (22) that changes the frequency of the alternating current,
It is provided with a temperature detection unit that detects the temperature or air temperature of the motor.
If the temperature detected by the temperature detection unit is equal to or lower than the threshold value, the control unit performs the freeze lock release process without changing the frequency of the alternating current within the control cycle.
An electronic control device that performs foreign matter removal processing that changes the frequency of the alternating current according to the temperature detected within the control cycle when the temperature exceeds the threshold value . The control unit includes a timer that measures the control cycle of the freeze lock release process.
The electronic control device according to claim 1 , wherein the frequency of the alternating current is changed according to the difference between the temperature detected by the temperature detection unit and the target temperature of the induction heating, and the freeze lock release process is performed. The electronic control device according to claim 1 or 2 , wherein the control unit determines whether or not to change the frequency of the alternating current in the foreign matter removing process according to the temperature detected by the temperature detection unit. The electronic control device according to any one of claims 1 to 3 , further comprising a switch (32) that can be operated from the outside in order to change the frequency. A capacitor (C1, C2, C3) connected between the winding terminals of the motor is provided.
The electronic control device according to any one of claims 1 to 4, wherein the control unit energizes the alternating current by LC resonance. The electronic control device according to claim 5 , wherein the capacitance of the capacitor is set so that the frequency of the LC resonance does not match the harmonic component of the drive frequency of the motor. A switch (SW1, SW2, SW3) arranged between the winding terminal of the motor and the capacitor is provided.
The electronic control device according to claim 5 , wherein the control unit turns on the switch when the alternating current is applied. A plurality of the capacitors and the switches are provided according to the number of phases of the motor.
The electronic control device according to claim 7 , wherein the control unit changes the resonance frequency by changing the combination in which the switch is turned on. The electronic control device according to any one of claims 1 to 8 , wherein the control unit switches the phase of the winding that energizes the alternating current at predetermined time intervals. Any of claims 1 to 9 , wherein the control unit outputs a diagnostic signal for notifying the user if the freeze lock of the motor is not released even after the freeze lock release process is executed for a predetermined time. The electronic control device according to paragraph 1.

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