Control device, control method, and program

Abstract

A control device (34) that controls a fan motor (22) that rotates a fan (24) that blows air to an object to be cooled (14) is provided with a processor (74) and memories (76, 78). The processor determines whether or not the fan motor is submerged in water, and when it is determined that the fan motor is submerged in water, the fan motor is operated after the water submersion of the fan motor is eliminated.

Description

Citation of related applications

[0001] This application claims priority based on Japanese patent application No. 2022-161886 filed on October 6, 2022, and all the contents of the patent application are incorporated into this specification by reference. Technical Field

[0002] The present disclosure relates to a control device, a control method, and a program for controlling a fan motor that rotates a fan that sends air to a cooling object. Background Art

[0003] In the past, a fan motor that rotates a fan that blows air to a cooling object is known (for example, refer to Japanese Patent Laid-Open No. 2019-73200). Among such fan motors, there is a fan motor that is arranged at a position that may be submerged in water. Summary of the invention

[0004] As a result of detailed studies, the inventors have found that a fan motor disposed at a location that may be flooded may have water droplets remaining inside after the flooding is eliminated.

[0005] The present disclosure is made in view of the above-mentioned technical problems, and as an example, an object thereof is to provide a control device, a control method, and a program that can suppress water droplets from remaining inside after water submergence is eliminated.

[0006] A first method disclosed herein is a control device for controlling a fan motor that rotates a fan that supplies air to a cooling object, the control device comprising a processor and a memory, wherein the processor determines whether the fan motor is submerged in water, and when it is determined that the fan motor is submerged in water, the processor operates the fan motor after the submergence of water in the fan motor is eliminated.

[0007] According to the control device of the first aspect of the present disclosure, it is possible to suppress water droplets from remaining inside the fan motor after the fan motor is no longer submerged in water.

[0008] A second aspect of the present disclosure is a control method for controlling a fan motor that rotates a fan that supplies air to a cooling object, the control method comprising: determining whether the fan motor is submerged in water, and if it is determined that the fan motor is submerged in water, operating the fan motor after the submergence of the fan motor is eliminated.

[0009] According to the control method of the second aspect of the present disclosure, it is possible to suppress water droplets from remaining inside the fan motor after the fan motor is no longer submerged in water.

[0010] The third method of the present disclosure is a program for causing a computer to execute a process for controlling a fan motor that rotates a fan that supplies air to a cooling object, the process comprising: determining whether the fan motor is submerged in water, and if it is determined that the fan motor is submerged in water, operating the fan motor after the water submergence of the fan motor is eliminated.

[0011] According to the program of the third aspect of the present disclosure, it is possible to suppress water droplets from remaining inside the fan motor after the fan motor is no longer submerged in water. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram showing an example of a cooling system. Figure 2 It is a longitudinal sectional view showing an example of a fan motor. Figure 3 This is a block diagram showing an example of a control circuit. Figure 4 This is an explanatory diagram for explaining an example of how water droplets adhering to the rotor are scattered by the centrifugal force of the rotor. Figure 5 This is a flowchart showing an example of the motor control process. DETAILED DESCRIPTION

[0013] First, the structure of the cooling system 10 according to one embodiment of the present disclosure will be described.

[0014] As an example, Figure 1 As shown, a cooling system 10 according to an embodiment of the present disclosure is a system for cooling an engine 12 of a vehicle such as an automobile, and includes a radiator 14 and a fan device 16. The radiator 14 is connected to the engine 12 via a pipe 18. Cooling water circulates through the pipe 18 inside the radiator 14 and inside the engine 12. The radiator 14 is an example of a "cooling object" in the present disclosure.

[0015] The fan device 16 includes a shroud 20, a fan motor 22, and a fan 24. The fan motor 22 is fixed to the radiator 14 via the shroud 20. The fan 24 is fixed to the fan motor 22 and rotates as the fan motor 22 operates. The fan 24 sends air to the radiator 14 while rotating.

[0016] As an example, Figure 2 As shown, the fan motor 22 is an outer rotor type brushless motor including a rotor 26 , a stator 28 , a shaft 30 , a center piece 32 , a control circuit 34 , a substrate housing 36 , and a connector member 38 .

[0017] The rotor 26 includes a rotor housing 40 and a rotor magnet 42. The rotor housing 40 is formed in a top cylindrical shape, and a cylindrical bearing receiving portion 44 (i.e., an inner cylindrical portion) is formed in the central portion of the top wall portion of the rotor housing 40. A pair of bearings 46 are received in the bearing receiving portion 44, and the rotor 26 is rotatably supported on the shaft 30 via the pair of bearings 46. The rotor magnet 42 is fixed to the inner circumferential surface of the outer cylindrical portion of the rotor housing 40 by, for example, an adhesive.

[0018] The stator 28 is housed inside the rotor housing 40 and includes a stator core 48, an insulator 50, and a plurality of windings 52. The stator core 48 has a plurality of pole teeth 54 extending radially around the shaft 30, and each winding 52 is wound around each pole tooth 54 via the insulator 50.

[0019] The center piece 32 has a plate-like portion 56. The plate-like portion 56 faces the opening of the rotor housing 40. The stator 28 is fixed to the plate-like portion 56 by screws or the like, whereby the stator 28 is held by the plate-like portion 56. A recessed portion 58 opening toward the stator 28 is formed in the center of the plate-like portion 56, and the shaft 30 is fixed in the recessed portion 58.

[0020] The control circuit 34 includes a plurality of switching elements for driving the stator 28. The control circuit 34 is arranged opposite to the plate-shaped portion 56 on the side opposite to the rotor 26 of the plate-shaped portion 56. The control circuit 34 is fixed to the plate-shaped portion 56 by screws or the like. The control circuit 34 is an example of a "control device" of the present disclosure.

[0021] The substrate housing 36 is fixed to the plate-shaped portion 56 from the side opposite to the rotor 26. The control circuit 34 is accommodated inside the substrate housing 36. The connector member 38 is fixed to the plate-shaped portion 56 by screws or the like. The connector member 38 has a connector terminal 60 electrically connected to the control circuit 34 and a connector housing 62 accommodating the connector terminal 60.

[0022] In the fan motor 22, the current flowing through the plurality of windings 52 is switched by the switching operation of the plurality of switching elements, and the stator 28 forms a rotating magnetic field. When the stator 28 forms a rotating magnetic field, an attractive force and a repulsive force are generated between the stator 28 and the rotor magnet 42, thereby rotating the rotor 26. The fan 24 (see Figure 1 ) is fixed to the rotor 26, and the fan 24 rotates integrally with the rotor 26.

[0023] As an example, Figure 3As shown, the control circuit 34 includes a computer 72. The computer 72 includes a CPU 74 (Central Processing Unit), a ROM 76 (Read Only Memory), and a RAM 78 (Random Access Memory). The CPU 74, the ROM 76, and the RAM 78 are connected via a bus 80 so as to be able to communicate with each other. A motor control program 82 is stored in the ROM 76. The computer 72 is an example of a "computer" in the present disclosure, the CPU 74 is an example of a "processor" in the present disclosure, the ROM 76 and the RAM 78 are examples of "memory" in the present disclosure, and the motor control program 82 is an example of a "program" in the present disclosure.

[0024] The CPU 74 reads out the motor control program 82 from the ROM 76, and executes the read motor control program 82 in the RAM 78. The CPU 74 executes the motor control process according to the motor control program 82 executed in the RAM 78. The motor control process is realized by operating the CPU 74 as a vehicle operation signal determination unit 84, a motor trial operation control unit 86, an abnormality determination unit 88, a motor stop control unit 90, a predetermined time determination unit 92, a flooding history determination unit 94, and a motor operation control unit 96.

[0025] The vehicle operation signal determination unit 84 determines whether a vehicle operation signal (i.e., a signal indicating that the rotor 26 is rotated relative to the fan motor 22) output from an ECU (Electronic Control Unit, not shown) installed in the vehicle is input to the CPU 74. The vehicle operation signal is output from the ECU, for example, when the temperature of the radiator 14 rises and reaches a predetermined temperature.

[0026] In addition, the vehicle operation signal may be output from the ECU at a predetermined constant time interval. In addition, the vehicle operation signal may be output from the ECU when, for example, raindrops are detected by a raindrop sensor (not shown). In addition, the vehicle operation signal may be output from the ECU when the water level detected by a water level sensor (not shown) provided around the fan motor 22 rises and reaches a predetermined water level.

[0027] When the vehicle operation signal determination unit 84 determines that the vehicle operation signal is input to the CPU 74, the motor test control unit 86 performs a test operation (i.e., a test run) of the fan motor 22. As described later, the rotation speed of the fan motor 22 when the fan motor 22 is tested can be set to the rotation speed when the fan motor 22 is normally operated (hereinafter referred to as "normal rotation speed"), or can be set to a rotation speed lower than the normal rotation speed.

[0028] The abnormality determination unit 88 determines the abnormality of the fan motor 22 based on the current value and the rotation speed of the fan motor 22. Specifically, first, the abnormality determination unit 88 determines whether the current value supplied to the stator 28 exceeds a predetermined reference current value (i.e., whether it is an overcurrent). The reference current value is set to, for example, an upper limit value of the current value in a state where the fan motor 22 is operating normally without foreign matter intruding into the fan motor 22 or the fan motor 22 being flooded.

[0029] When foreign matter enters the fan motor 22 and locks the rotor 26, or when the fan motor 22 is submerged in water and the resistance of water 98 acts on the rotor 26 via the fan 24, the current value supplied to the stator 28 exceeds the reference current value. When the current value supplied to the stator 28 exceeds the reference current value, abnormalities such as the rotor 26 locking or the fan motor 22 being submerged in water may occur. Figure 3 The fan motor 22 is shown to be located at a lower position than the water 98 infiltrating the engine room and is submerged in the water.

[0030] Next, when it is determined that the current value supplied to the stator 28 exceeds the reference current value, the abnormality determination unit 88 determines whether the rotation speed of the fan motor 22 is above a predetermined rotation speed. The predetermined rotation speed is set, for example, to a rotation speed higher than the rotation speed (for example, zero rotation speed) in a state where foreign matter has penetrated into the fan motor 22 and the rotor 26 is locked.

[0031] Although the rotor 26 is not locked due to foreign matter intruding into the fan motor 22, the rotation speed of the fan motor 22 becomes higher than the predetermined rotation speed in a state where the resistance of the water 98 acts on the rotor 26 via the fan 24 because the fan motor 22 is submerged in water. Therefore, based on the rotation speed of the fan motor 22, it is possible to determine whether the rotor 26 is locked or whether the fan motor 22 is submerged in water.

[0032] Thus, when the current value supplied to the stator 28 exceeds the reference current value and the rotation speed of the fan motor 22 is equal to or higher than the prescribed rotation speed, the abnormality determination unit 88 determines that the fan motor 22 is submerged in water. On the other hand, when the current value supplied to the stator 28 exceeds the reference current value but the rotation speed of the fan motor 22 is not equal to or higher than the prescribed rotation speed, the abnormality determination unit 88 determines that the rotor 26 is locked.

[0033] The motor stop control unit 90 stops the fan motor 22 when the abnormality determination unit 88 determines that the fan motor 22 is submerged in water. The motor stop control unit 90 also stops the fan motor 22 when the abnormality determination unit 88 determines that the rotor 26 is locked.

[0034] The prescribed time determination unit 92 determines whether the time (hereinafter referred to as "elapsed time") that has elapsed since the motor stop control unit 90 stopped the fan motor 22 exceeds a predetermined prescribed time. The prescribed time is set, for example, to the time required from when the fan motor 22 is submerged in water to when the water submersion of the fan motor 22 is eliminated to when the drainage from the inside of the fan motor 22 is completed. Even if the water submersion of the fan motor 22 is eliminated, if the elapsed time is within the prescribed time, water still remains in the fan motor 22. On the other hand, if the elapsed time exceeds the prescribed time after the water submersion of the fan motor 22 is eliminated, the drainage from the inside of the fan motor 22 is completed.

[0035] When the predetermined time determination unit 92 determines that the elapsed time exceeds the predetermined time, the motor trial control unit 86 again trial-starts the fan motor 22. Even when the fan motor 22 is submerged in water, after the submergence of the fan motor 22 is eliminated, when the elapsed time exceeds the predetermined time, the water is discharged from the inside of the fan motor 22. Therefore, when the water is discharged from the inside of the fan motor 22, in a state where the rotor 26 is not locked (that is, when there is no abnormality in the fan motor 22), the current value supplied to the stator 28 becomes less than the reference current value. In this case, the abnormality determination unit 88 determines that the current value supplied to the stator 28 does not exceed the reference current value (that is, the submergence of the fan motor 22 is eliminated).

[0036] When the abnormality determination unit 88 determines that the current value supplied to the stator 28 does not exceed the reference current value (that is, the fan motor 22 has no abnormality), the flooding history determination unit 94 determines whether there is a history of determining that the fan motor 22 is flooded by the most recent determination processing of the abnormality determination unit 88. The history of the fan motor 22 being flooded determined by the abnormality determination unit 88 is stored in the RAM 78, for example.

[0037] When the flooding history determination unit 94 determines that there is a history of the fan motor 22 being flooded by the abnormality determination unit 88, the motor operation control unit 96 operates the fan motor 22 for a predetermined time. Figure 4An example of a situation in which water droplets 100 attached to the rotor 26 are scattered by the centrifugal force of the rotor 26 is shown. The predetermined time is set to, for example, the time required to scatter the water droplets 100 attached to the rotor 26 of the fan motor 22 by the centrifugal force of the rotor 26. By operating the fan motor 22 under the control of the motor operation control unit 96, the fan motor 22 is operated to perform a water scattering operation for scattering the water droplets 100 attached to the rotor 26 by the centrifugal force of the rotor 26. The rotation speed of the fan motor 22 when performing the water scattering operation may be set to, for example, the upper limit value of the rated rotation speed of the fan motor 22. The motor operation control unit 96 stops the fan motor 22 after the predetermined time of operation.

[0038] On the other hand, when the flooding history determination unit 94 determines that there is no history of the fan motor 22 being flooded by the abnormality determination unit 88, the motor operation control unit 96 starts the operation of the fan motor 22 at the rotation speed specified by the vehicle operation signal. Thus, the air supply operation in the air supply mode is performed on the fan motor 22. For example, the air supply operation is performed until the motor stop signal is input from the ECU to the CPU 74.

[0039] Next, refer to Figure 5 A control method according to an embodiment of the present disclosure will be described.

[0040] exist Figure 5 In the motor control process shown, first, in step ST10, the vehicle operation signal determination unit 84 determines whether the vehicle operation signal output from the ECU installed in the vehicle is input to the CPU 74. In step ST10, if the vehicle operation signal is input to the CPU 74, the determination is affirmative, and the motor control process shifts to step ST12. In step ST10, if the vehicle operation signal is not input to the CPU 74, the determination is negative, and the motor control process executes the process of step ST10 again.

[0041] In step ST12, the motor test control unit 86 test-operates the fan motor 22. After the process of step ST12 is executed, the motor control process proceeds to step ST14.

[0042] In step ST14, the abnormality determination unit 88 determines whether the current value supplied to the stator 28 exceeds the reference current value (i.e., whether it is an overcurrent). In step ST14, if the current value supplied to the stator 28 exceeds the reference current value, the determination is affirmative, and the motor control process is transferred to step ST16. In step ST14, if the current value supplied to the stator 28 does not exceed the reference current value, the determination is negative, and the motor control process is transferred to step ST24.

[0043] In step ST16, the abnormality determination unit 88 determines whether the rotation speed of the fan motor 22 is greater than or equal to a predetermined rotation speed. In step ST16, if the rotation speed of the fan motor 22 is greater than or equal to the predetermined rotation speed, the determination is affirmative, and the motor control process is transferred to step ST18. In step ST16, if the rotation speed of the fan motor 22 is not greater than or equal to the predetermined rotation speed, the determination is negative, and the motor control process is transferred to step ST20.

[0044] In step ST18, the motor stop control unit 90 stops the fan motor 22. After the process of step ST18 is executed, the motor control process proceeds to step ST22.

[0045] In step ST20, the motor stop control unit 90 stops the fan motor 22. After the process of step ST20 is executed, the motor control process proceeds to step ST22.

[0046] In step ST22, the predetermined time determination unit 92 determines whether the elapsed time from the time when the fan motor 22 is stopped by the motor stop control unit 90 exceeds the predetermined time. In step ST22, if the elapsed time exceeds the predetermined time, the determination is affirmative, and the motor control process shifts to step ST12. In step ST22, if the elapsed time does not exceed the predetermined time, the determination is negative, and the motor control process executes the process of step ST22 again.

[0047] In step ST24, the flooding history determination unit 94 determines whether there is a history of determining that the fan motor 22 is flooded by the most recent determination process of the abnormality determination unit 88. In step ST24, if there is a history of determining that the fan motor 22 is flooded, the determination is affirmative, and the motor control process is transferred to step ST26. In step ST24, if there is no history of determining that the fan motor 22 is flooded, the determination is negative, and the motor control process is transferred to step ST28.

[0048] In step ST26, the motor operation control unit 96 operates the fan motor 22 for a predetermined time. As a result, the water droplets 100 attached to the rotor 26 are scattered by the centrifugal force of the rotor 26. The motor operation control unit 96 stops the fan motor 22 after the predetermined time. After executing the process of step ST26, the motor control process is transferred to step ST30.

[0049] In step ST28, the motor operation control unit 96 starts the operation of the fan motor 22 at the rotation speed specified by the vehicle operation signal. Thus, the fan motor 22 performs the air blowing operation in the air blowing mode. After the process of step ST28 is executed, the motor control process moves to step ST30.

[0050] In step ST30, the CPU 74 determines whether the condition for terminating the motor control process (i.e., the termination condition) is satisfied. As an example of the termination condition, a condition in which a motor stop signal is input from the ECU to the CPU 74 can be cited. When the motor stop signal is input to the CPU 74 while the fan motor 22 is operating, the operation of the fan motor 22 is stopped. In step ST30, if the termination condition is not satisfied, the determination is negative, and the motor control process is transferred to step ST14. In step ST30, if the termination condition is satisfied, the determination is positive, and the motor control process is terminated.

[0051] Next, the effects of one embodiment of the present disclosure will be described.

[0052] As described in detail above, the CPU 74 determines whether the fan motor 22 is submerged in water, and when it is determined that the fan motor 22 is submerged in water (step ST16: Yes), after the submergence of the fan motor 22 is eliminated (step ST14: No), the fan motor 22 is operated (step ST26). Therefore, it is possible to suppress water droplets from remaining inside the fan motor 22 after the submergence of the fan motor 22 is eliminated.

[0053] In addition, the CPU 74 determines whether the fan motor 22 is submerged in water based on the current value and the rotation speed of the fan motor 22. Therefore, for example, it is possible to determine whether the fan motor 22 is submerged in water without using a water level sensor or the like, and thus the number of components can be reduced compared to the case of using a water level sensor or the like.

[0054] In addition, after the water submergence of the fan motor 22 is eliminated (step ST14: No), the CPU 74 operates the fan motor 22 until the water droplets 100 attached to the rotor 26 of the fan motor 22 are scattered (step ST26). Therefore, by scattering the water droplets 100 attached to the rotor 26, it is possible to suppress the water droplets 100 from remaining inside the fan motor 22.

[0055] Next, a modification example of one embodiment of the present disclosure will be described.

[0056] In the above embodiment, the cooling object of the fan 24 is, for example, the radiator 14, but may be an object other than the radiator 14. In addition, for example, the cooling object may be a capacitor of an air conditioner, a battery of an HV (Hybrid Vehicle), a battery of an EV (Electric Vehicle), etc.

[0057] Furthermore, in the above-described embodiment, the cooling system 10 is applied to a vehicle such as an automobile as an example, but may also be applied to a special vehicle such as an amphibious vehicle.

[0058] In the above embodiment, the control circuit 34 is provided in the fan motor 22, but it may be provided independently of the fan motor 22. In addition, the control circuit 34 may be a part or the whole of the ECU.

[0059] In the above embodiment, the control circuit 34 includes a computer 72 having a CPU 74, a ROM 76, and a RAM 78, but a device including an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), and / or a PLD (Programmable Logic Device) may be applied instead of the computer 72. In addition, a combination of a hardware structure and a software structure may be applied instead of the computer 72.

[0060] The control unit and method described in the present disclosure may also be implemented by a special-purpose computer, which is provided by constituting a processor, and the above-mentioned processor is programmed to execute one or more functions embodied by a computer program. Alternatively, the device and method described in the present disclosure may be implemented by a special-purpose computer, which is provided by constituting a processor composed of a dedicated hardware logic circuit. Alternatively, the device and method described in the present disclosure may be implemented by one or more special-purpose computers, which are constituted by a combination of a processor that executes a computer program and one or more hardware logic circuits. In addition, the computer program may also be stored in a computer-readable non-temporary tangible storage medium as an instruction executed by a computer.

[0061] As mentioned above, one embodiment of the present disclosure has been described, but the present disclosure is not limited to the above, and it is obvious that various modifications other than the above can be made and implemented without departing from the scope of the concept of the present disclosure.

[0062] The following supplementary notes are disclosed with respect to the above-mentioned embodiment. (Note 1) A control device (34) controls a fan motor (22) for rotating a fan (24) for sending air to a cooling object (14), wherein: comprising a processor (74) and memory (76, 78), The processor determines whether the fan motor is submerged in water. When it is determined that the fan motor is submerged in water, the fan motor is operated after the submergence of the fan motor is eliminated. (Note 2) The control device as described in Supplementary Note 1, wherein the processor determines whether the fan motor is submerged in water based on a current value and a rotation speed of the fan motor. (Note 3) A control device as described in Appendix 1 or Appendix 2, wherein the processor operates the fan motor until water droplets attached to the rotor (26) of the fan motor are dispersed after the water submergence of the fan motor is eliminated. (Note 4) A control method for controlling a fan motor that rotates a fan that blows air toward a cooling object, wherein the control method comprises: Determining whether the fan motor is submerged in water; When it is determined that the fan motor is submerged in water, the fan motor is operated after the submergence of the fan motor is eliminated. (Note 5) A control method as described in Supplementary Note 4, wherein whether the fan motor is submerged in water is determined based on a current value and a rotation speed of the fan motor. (Note 6) A control method as described in Appendix 4 or Appendix 5, wherein, after the water submergence of the fan motor is eliminated, the fan motor is operated until water droplets attached to the rotor (26) of the fan motor are dispersed. (Note 7) A program (82) for causing a computer (72) to execute a process for controlling a fan motor for rotating a fan for blowing air to a cooling object, wherein: The above processing includes: Determining whether the fan motor is submerged in water; When it is determined that the fan motor is submerged in water, the fan motor is operated after the submergence of the fan motor is eliminated. (Note 8) A program as recited in Supplementary Note 7, wherein whether or not the fan motor is submerged in water is determined based on a current value and a rotation speed of the fan motor. (Note 9) A control device as recorded in Supplement 7 or Supplement 8, wherein after the water submergence of the fan motor is eliminated, the fan motor is operated until water droplets attached to the rotor (26) of the fan motor are dispersed.

Claims

1. A control device, the control device (34) controlling a fan motor (22) for rotating a fan (24) for sending air to a cooling object (14), comprising a processor (74) and memory (76, 78), The processor determines whether the fan motor is submerged in water. When it is determined that the fan motor is submerged in water, the fan motor is operated after the submergence of the fan motor is eliminated.

2. The control device according to claim 1, It is characterized in that The processor determines whether the fan motor is submerged in water based on a current value and a rotation speed of the fan motor.

3. The control device according to claim 1 or 2, It is characterized in that After the water submergence of the fan motor is eliminated, the processor operates the fan motor until water droplets attached to the rotor (26) of the fan motor are dispersed.

4. A control method for controlling a fan motor that rotates a fan that blows air to a cooling object, the control method include: Determining whether the fan motor is submerged in water; When it is determined that the fan motor is submerged in water, the fan motor is operated after the submergence of the fan motor is eliminated.

5. A program (82) for causing a computer (72) to execute a process for controlling a fan motor for rotating a fan for blowing air toward a cooling object, The processing include: Determining whether the fan motor is submerged in water; When it is determined that the fan motor is submerged in water, the fan motor is operated after the submergence of the fan motor is eliminated.

Images