Cooling System

Abstract

To suppress abnormality occurring to a first fan or a second fan caused by freezing lock while suppressing an increase in number of dedicated components for detecting the freezing lock.SOLUTION: A cooling system includes: a first cooling device which is mounted on a vehicle equipped with an engine and a motor device having a motor, has a first radiator and a first fan that cools cooling water of the first radiator, and cools one of the engine and the motor device; a second cooling device which has a second radiator and a second fan that cools cooling water of the second radiator, and cools the other of the engine and the motor device; and a control device controlling the first fan and the second fan. The system is provided with a freezing lock detection part detecting a freezing lock of the first fan. The control device stops driving the first fan and the second fan when the freezing lock of the first fan is detected by the freezing lock detection part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a cooling system. [Background technology]

[0002] Conventionally, a cooling system of this type has been proposed that is mounted on a vehicle having an engine, a motor, and a PCU incorporating an inverter for driving the motor, and that includes a first cooling device having a first radiator and a first fan that blows air to the first radiator and cools the engine, and a second cooling device having a second radiator and a second fan that blows air to the second radiator and cools the motor and the PCU (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-119242 A Summary of the Invention [Problem to be solved by the invention]

[0004] In such a cooling system, if the first fan or the second fan continues to be controlled to rotate at a high rotation speed when the fan is freeze-locked, there is a possibility that an abnormality due to freeze lock will occur in the first fan or the second fan. For this reason, it is necessary to detect freeze lock in the first fan or the second fan, but providing a dedicated sensor for each of them would result in a large number of dedicated parts.

[0005] The cooling system of the present invention has a primary objective to prevent abnormalities in the first fan and the second fan caused by freeze lock while preventing an increase in the number of dedicated parts for detecting freeze lock. [Means for solving the problem]

[0006] In order to achieve the above-mentioned main object, the cooling system of the present invention employs the following means.

[0007] The cooling system of the present invention comprises: The vehicle is equipped with a motor device having an engine and a motor, a first cooling device that has a first radiator and a first fan that cools the cooling water of the first radiator and cools one of the engine and the motor device; a second cooling device that has a second radiator and a second fan that cools the cooling water of the second radiator and cools the other of the engine and the motor device; A control device that controls the first fan and the second fan; A cooling system comprising: a freeze lock detection unit that detects a freeze lock of the first fan, When the freeze lock detection unit detects a freeze lock of the first fan, the control device stops driving the first fan and the second fan. The gist of the present invention is as follows.

[0008] In the cooling system of the present invention, when a freeze lock of the first fan is detected by a freeze lock detection unit that detects a freeze lock of the first fan, the first fan and the second fan are stopped. When the first fan is freeze locked, it is considered that the second fan is also freeze locked. Therefore, by stopping the first fan and the second fan when a freeze lock of the first fan is detected by the freeze lock detection unit, it is possible to prevent the occurrence of abnormalities in the first fan or the second fan due to freeze lock without providing a dedicated part for detecting freeze lock of the second fan, that is, while preventing an increase in the number of dedicated parts for detecting freeze lock.

[0009] In the cooling system of the present invention, the first fan may cool a refrigerant of an air conditioner that conditions the vehicle interior in addition to cooling the coolant of the first radiator, and the freeze lock detection unit may determine whether the first fan is freeze locked based on a refrigerant pressure of the refrigerant. In this case, the freeze lock detection unit may determine whether the first fan is freeze locked by comparing a first refrigerant pressure, which is the refrigerant pressure when the first fan is stopped, with a second refrigerant pressure, which is the refrigerant pressure when the first fan is driven.

[0010] In the cooling system of the present invention, the freeze lock detection unit may determine whether or not the first fan is freeze locked only when the outside air temperature is equal to or lower than a predetermined temperature, because when the outside air temperature is high, the possibility of the first fan or the second fan being freeze locked is sufficiently low.

[0011] In the cooling system of the present invention, the first fan and the second fan may be disposed close to each other. In this case, when the first fan is freeze-locked, it is more likely that the second fan is freeze-locked. Therefore, the significance of applying the present invention is even greater. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing the configuration of an automobile 10 equipped with a cooling system according to an embodiment of the present invention. [Diagram 2] 4 is a flowchart showing an example of a processing routine executed by a main ECU 60. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Next, a mode for carrying out the present invention will be described using examples. EXAMPLES

[0014] FIG. 1 is a schematic diagram showing the configuration of an automobile 10 equipped with a cooling system according to an embodiment of the present invention. The automobile 10 of the embodiment is configured as a series hybrid vehicle or a parallel hybrid vehicle equipped with an engine 11 and a motor 12. In addition to the engine 11 and the motor 12, the automobile 10 also includes a power control unit (hereinafter referred to as "PCU") 13, a battery 14, an air conditioner 20, a cooling device 40, a cooling device 50, and a main electronic control unit (hereinafter referred to as "main ECU") 60. In the embodiment, the engine 11, the motor 12, the PCU 13, a part of the air conditioner 20, the cooling device 40, and the cooling device 50 are arranged in an engine room at the front of the vehicle. The cooling system of the embodiment corresponds to the cooling device 40, the cooling device 50, and the main ECU 60.

[0015] The engine 11 is configured as, for example, an internal combustion engine. The motor 12 is configured as, for example, a synchronous generator-motor. The PCU 13 has an inverter that converts DC power into AC power to drive the motor 12, a converter that boosts the power from a battery and supplies it to the inverter, and the like. The battery 14 is configured as, for example, a lithium ion secondary battery or a nickel-metal hydride secondary battery, and is connected to the PCU 13 via a power line.

[0016] The air conditioner 20 is configured as a device for conditioning the interior of a vehicle, and includes a refrigeration cycle 21, a blower fan 28, and an air conditioning electronic control unit (hereinafter referred to as "air conditioning ECU") 30. The refrigeration cycle 21 has a refrigerant circulation flow path 22, a compressor 23, a condenser 24, an expansion valve 25, and an evaporator 26. The circulation flow path 22 is formed by including the compressor 23, the condenser 24, the expansion valve 25, and the evaporator 26 in this order. The compressor 23 compresses the gaseous refrigerant at low temperature and low pressure to make it a high temperature and high pressure gas. The condenser 24 changes the gaseous refrigerant into a room temperature and high pressure liquid at high temperature and high pressure. The expansion valve 25 changes the liquid refrigerant at room temperature and high pressure into a low temperature and low pressure liquid. The evaporator 26 changes the liquid refrigerant into a low temperature and low pressure gas at low temperature and low pressure. The blower fan 28 blows the air that has been cooled by heat exchange with the evaporator 26 into the passenger compartment.

[0017] Although not shown, the air conditioning ECU 30 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. Various signals are input to the air conditioning ECU 30 via an input port. Examples of the signals input to the air conditioning ECU 30 include a refrigerant pressure Pr from a pressure sensor 27 attached between the condenser 24 and the expansion valve 25 of the circulation flow path 22, and an on / off signal from an air conditioning switch 31 that instructs turning on and off the air conditioning in the vehicle cabin. Various control signals are output from the air conditioning ECU 30 via an output port. Examples of the signals output from the air conditioning ECU 30 include a control signal to the compressor 23 and a control signal to the blower fan 28.

[0018] The cooling device 40 is configured as a device for cooling the engine 11, and includes a circulation flow path 41 for cooling water, a water pump 42, a radiator 43, and a fan 44. The circulation flow path 41 is formed to include the engine 11 and the radiator 43. The water pump 42 is provided in the circulation flow path 41, and circulates the cooling water in the circulation flow path 41. The radiator 43 is disposed at the front part of the engine room, and cools the cooling water by heat exchange with the air caused by running or the air by the fan 44. The fan 44 is rotationally driven by a motor 45, and blows air to the radiator 43 and the condenser 24 of the air conditioner 20, thereby cooling the cooling water in the radiator 43 and the refrigerant in the condenser 24. The motor 45 is configured as a DC motor.

[0019] The cooling device 50 is configured as a device for cooling the motor 12 and the PCU 13, and includes a circulation flow path 51 for cooling water, a water pump 52, a radiator 53, and a fan 54. The circulation flow path 51 is formed to include the motor 12, the PCU 13, and the radiator 53. The water pump 52 is provided in the circulation flow path 51 and circulates the cooling water in the circulation flow path 51. The radiator 53 is arranged adjacent to the radiator 43 in the left-right direction of the vehicle at the front part of the engine room, and cools the cooling water by heat exchange with the air caused by running wind and air by the fan 54. The fan 54 is arranged adjacent to the fan 44 in the left-right direction of the vehicle, and is rotationally driven by a motor 55 to blow air to the radiator 53 and cool the cooling water in the radiator 53. The motor 45 is configured as a DC motor.

[0020] Although not shown, the main ECU 60 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, an input / output port, and a communication port. Various signals are input to the main ECU 60 via an input port. Examples of the signals input to the main ECU 60 include signals from various sensors that detect the state of the engine 11 and signals from various sensors that detect the state of the motor 12. Examples of the signals input to the main ECU 60 include a cooling water temperature Tw1 from a temperature sensor (not shown) that detects the temperature of the cooling water of the cooling device 40, and a cooling water temperature Tw2 from a temperature sensor (not shown) that detects the temperature of the cooling water of the cooling device 50. Examples of the signals input to the main ECU 60 include an ignition signal from an ignition switch 61, a vehicle speed V from a vehicle speed sensor 62, and an outside air temperature Tout from an outside air temperature sensor 63. Various control signals are output from the main ECU 60 via an output port. Examples of the signals output from the main ECU 60 include various control signals for controlling the operation of the engine 11 and various control signals for controlling the drive of the PCU 13 (inverter and converter). Other examples of the control signals include a control signal to the water pump 42 and the fan 44 (motor 45) of the cooling device 40, and a control signal to the water pump 52 and the fan 54 (motor 55) of the cooling device 50. The main ECU 60 is communicatively connected to the air conditioning ECU 30 via a communication port.

[0021] In the cooling system thus configured and mounted on the automobile 10 of the embodiment, the main ECU 60 controls the operation of the water pump 42 and the fan 44 (motor 45) based on the coolant temperature Tw1 of the cooling device 40, and also controls the operation of the water pump 52 and the fan 54 (motor 55) based on the coolant temperature Tw2 of the cooling device 50. When the air conditioning switch 31 is on, the air conditioning ECU 30 controls the operation of the compressor 23 and the blower fan 28. Hereinafter, such control of the operation of the fans 44 and 54 is referred to as "normal control."

[0022] Next, the operation of the cooling system thus configured and mounted on the automobile 10 of the embodiment will be described. Fig. 2 is a flow chart showing an example of a processing routine executed by the main ECU 60. This routine is periodically executed when normal control of the fans 44 and 54 is not permitted in the current trip, the engine 11 is running, and the compressor 23 of the air conditioner 20 is operating.

[0023] 2 is executed, the main ECU 60 first inputs the vehicle speed V and the outside air temperature Tout (step S100). Here, the vehicle speed V is input with a value detected by the vehicle speed sensor 62. The outside air temperature Tout is input with a value detected by the outside air temperature sensor 63.

[0024] After the data is input in this manner, the outside air temperature Tout is compared with a threshold value Toutth (step S110). Here, the threshold value Toutth is a threshold value used to determine whether or not there is a possibility that the fan 44 or the fan 54 is frozen and locked, and is set to, for example, about 0°C to 5°C, taking into consideration the detection error of the outside air temperature sensor 63, etc.

[0025] If the outside air temperature Tout is higher than the threshold value Toutth in step S110, it is determined that the fan 44 and the fan 54 are not freeze-locked (step S220), normal control of the fan 44 and the fan 54 is permitted (step S230), and this routine is terminated.

[0026] When the outside air temperature Tout is equal to or lower than the threshold value Toutref in step S110, it is determined that the fan 44 or the fan 54 may be frozen and locked, and the vehicle speed V is compared with the threshold value Vth (step S120). Here, the threshold value Vth is a threshold value used to determine whether the vehicle is substantially stopped, i.e., whether the traveling wind is sufficiently weak or not, and is set to, for example, about 0 km / h to 5 km / h, taking into consideration the detection error of the vehicle speed sensor 62, etc. The reason for this process will be described later.

[0027] When the vehicle speed V is higher than the threshold value Vref in step S120, it is determined that the vehicle is not substantially stopped, i.e., the traveling wind is relatively large, and the process waits for the vehicle speed V to drop below the threshold value Vref. At this time, since it is unclear whether the fan 44 or the fan 54 is frozen and locked, it is preferable to limit the driving of the fan 44 or the fan 54. Examples of such limitations include stopping the driving of the fan 44 or the fan 54, or controlling the rotation speed of the fan 44 or the fan 54 to a relatively low rotation speed.

[0028] When the vehicle speed V is equal to or less than the threshold value Vth in step S120, it is determined that the vehicle is substantially stopped, i.e., the wind generated while the vehicle is moving is sufficiently small. If the fan 44 is being driven, it is stopped (step S130). The refrigerant pressure Pr of the air conditioning device 20 is input (step S140). The input refrigerant pressure Pr is set as the reference refrigerant pressure Pr (step S150. Here, the refrigerant pressure Pr is a value detected by the pressure sensor 27 and is input by communication via the air conditioning ECU 30.

[0029] Next, the fan 44 is driven to rotate at a relatively low rotation speed (step S160), the refrigerant pressure Pr of the air conditioner 20 is input (step S170), and the input refrigerant pressure Pr is compared with the reference refrigerant pressure Prref (step S180). Consideration is given to the case where the vehicle speed V is equal to or less than the threshold value Vref, that is, the traveling wind is sufficiently small. At this time, if the fan 44 rotates normally, the refrigerant is cooled in the condenser 24 of the air conditioner 20 by the air blown by the fan 44, and the refrigerant pressure Pr, which is the pressure of the refrigerant from the condenser 24, drops accordingly. On the other hand, if the fan 44 is frozen locked, the traveling wind is sufficiently small and the fan 44 does not blow air, so that the temperature of the refrigerant does not drop in the condenser 24 and the refrigerant pressure Pr is approximately maintained. The process of step S160 is performed taking this into consideration. When the vehicle speed V is relatively high, that is, when the wind generated while traveling is relatively high, even if the fan 44 is frozen-locked, the refrigerant temperature in the condenser 24 may drop due to the wind generated while traveling, causing the refrigerant pressure Pr to drop. Therefore, when the refrigerant pressure Pr drops, it is difficult to determine whether the drop in the refrigerant pressure Pr is due to the blowing of air by the fan 44 or the wind generated while traveling. For this reason, in this embodiment, the process from step S130 onwards is executed when the vehicle speed V is equal to or lower than the threshold value Vref.

[0030] When the refrigerant pressure Pr of the air conditioner 20 is equal to or greater than the reference refrigerant pressure Prref in step S180, it is determined whether or not the fan 44 has been driven for a predetermined time (e.g., several tens of seconds) (step S190), and if it is determined that the fan 44 has not been driven for the predetermined time, the process returns to step S160.

[0031] If it is determined in step S180 that the refrigerant pressure Pr of the air conditioner 20 is lower than the reference refrigerant pressure Prref before it is determined in step S190 that the drive of the fan 44 has continued for a predetermined time, it is determined that the fan 44 is not freeze locked (step S220). Since the fans 44 and 54 are arranged adjacent to each other in the left-right direction of the vehicle, it can be determined that when the fan 44 is not freeze locked, it is highly likely that the fan 54 is not freeze locked either. In this case, normal control of the fans 44 and 54 is permitted (step S230), and this routine ends.

[0032] If it is not determined in step S180 that the refrigerant pressure Pr of the air conditioner 20 is lower than the reference refrigerant pressure Prref, and it is determined in step S190 that the driving of the fan 44 has continued for a predetermined time, it is determined that the fan 44 and the fan 54 are freeze-locked (step S200). Since the fan 44 and the fan 54 are arranged adjacent to each other in the left-right direction of the vehicle, when the fan 44 is freeze-locked, it can be determined that there is a high possibility that the fan 54 is also freeze-locked. In this case, the driving of the fan 44 and the fan 54 is stopped (step S210), and this routine ends.

[0033] In this way, whether or not the fan 44 is freeze locked is determined by comparing the refrigerant pressure Pr (reference refrigerant pressure Prref) when the fan 44 is stopped with the refrigerant pressure Pr of the air conditioner 20 when the fan 44 is driven, and when it is determined that the fan 44 is freeze locked, it is determined that there is a high possibility that the fan 54 is also freeze locked, and the driving of the fans 44 and 54 is stopped. This makes it possible to prevent abnormalities caused by freeze lock in the fans 44 and 54 without providing a dedicated part (sensor, etc.) for detecting freeze lock in the fan 54, in other words, to prevent an increase in the number of dedicated parts for detecting freeze lock.

[0034] During a trip, if the temperature in the engine compartment rises due to heat generated by the engine 11 or the motor 12, the freeze lock of the fans 44 and 54 may be released. For this reason, in this embodiment, as described above, the processing routine of Fig. 2 is periodically executed during the current trip when normal control of the fans 44 and 54 is not permitted, the engine 11 is running, and the compressor 23 of the air conditioner 20 is operating.

[0035] In the cooling system mounted on the automobile 10 of the embodiment described above, when it is determined that the fan 44 is freeze locked based on the refrigerant pressure Pr of the air conditioner 20, it is determined that there is a high possibility that the fan 54 is also freeze locked, and the driving of the fans 44 and 54 is stopped. This makes it possible to prevent the occurrence of abnormalities in the fans 44 and 54 due to freeze lock without providing a dedicated part (sensor, etc.) for detecting the freeze lock of the fan 54, in other words, to prevent an increase in the number of dedicated parts for detecting freeze lock.

[0036] In the cooling system mounted on the automobile 10 of the embodiment, when the outside air temperature Tout is equal to or lower than the threshold value Toutref and the vehicle speed V is equal to or lower than the threshold value Vref, it is determined whether or not the fan 44 is frozen-locked based on the refrigerant pressure Pr of the air conditioner 20. However, it may also be determined whether or not the fan 44 is frozen-locked based on the refrigerant pressure Pr of the air conditioner 20 when the vehicle speed V is equal to or lower than the threshold value Vref, regardless of the outside air temperature Tout.

[0037] In the cooling system mounted on the automobile 10 of the embodiment, when the outside air temperature Tout is equal to or lower than the threshold value Toutref and the vehicle speed V is equal to or lower than the threshold value Vref, it is determined whether the fan 44 is freeze-locked based on the refrigerant pressure Pr of the air conditioner 20, and when it is determined that the fan 44 is freeze-locked, it is determined that the fan 54 is also freeze-locked, and the driving of the fans 44 and 54 is stopped. However, it is also possible to provide a current sensor that detects the current of the motor 45, and when the outside air temperature Tout is equal to or lower than the threshold value Toutref, it is determined whether the fan 44 is freeze-locked based on whether an overcurrent flows through the motor 45, and when it is determined that the fan 44 is freeze-locked, it is determined that the fan 54 is also freeze-locked, and the driving of the fans 44 and 54 is stopped. Alternatively, a current sensor may be provided to detect the current of motor 55, and when the outside air temperature Tout is equal to or lower than a threshold value Toutref, it may be determined whether fan 54 is freeze locked based on whether an overcurrent is flowing through motor 55. If it is determined that fan 54 is freeze locked, it may be determined that there is a high possibility that fan 44 is also freeze locked, and the driving of fans 44 and 54 may be stopped.

[0038] In the cooling system mounted on the automobile 10 of the embodiment, the cooling device 40 for cooling the engine 11 has a fan 44 for cooling the coolant of the radiator 43 and the refrigerant of the air conditioner 20, and the cooling device 50 for cooling the motor 12 and the PCU 13 has a fan 54 for cooling the coolant of the radiator 53. However, the cooling device 40 for cooling the engine 11 may have a fan 44 for cooling the coolant of the radiator 43, and the cooling device 50 for cooling the motor 12 and the PCU 13 may have a fan 54 for cooling the coolant of the radiator 53 and the refrigerant of the air conditioner 20. In this case, when the outside air temperature Tout is equal to or lower than the threshold value Toutref and the vehicle speed V is equal to or lower than the threshold value Vref, it may be determined whether or not the fan 54 is frozen locked based on the refrigerant pressure Pr of the air conditioner 20, and when it is determined that the fan 54 is frozen locked, it may be determined that the fan 44 is also frozen locked, and the driving of the fans 44 and 54 may be stopped.

[0039] The correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be described below. In the embodiment, one of the cooling devices 40, 50 corresponds to the "first cooling device", the other of the cooling devices 40, 50 corresponds to the "second cooling device", and the main ECU 60 corresponds to the "control device" and the "freeze lock detection unit".

[0040] The correspondence between the main elements of the Examples and the main elements of the invention described in the Summary of the Problem column does not limit the elements of the invention described in the Summary of the Problem column, since the Examples are examples for specifically explaining the mode for implementing the invention described in the Summary of the Problem column. In other words, the interpretation of the invention described in the Summary of the Problem column should be based on the description in that column, and the Examples are merely a specific example of the invention described in the Summary of the Problem column.

[0041] Although the form for carrying out the present invention has been described above using examples, the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be carried out in various forms without departing from the scope of the gist of the present invention. [Industrial Applicability]

[0042] The present invention can be used in the cooling system manufacturing industry and the like. [Explanation of symbols]

[0043] 1 automobile, 11 engine, 12 motor, 13 PCU, 14 battery, 20 air conditioning device, 21 refrigeration cycle, 22 circulation flow path, 23 compressor, 24 condenser, 25 expansion valve, 26 evaporator, 27 pressure sensor, 28 blower fan, 30 air conditioning ECU, 31 air conditioning switch, 40 cooling device, 41 circulation flow path, 42 water pump, 43 radiator, 44 fan, 45 motor, 50 cooling device, 51 circulation flow path, 52 water pump, 53 radiator, 54 fan, 55 motor, 60 main ECU, 61 ignition switch, 62 vehicle speed sensor, 63 outside air temperature sensor.

Claims

1. The vehicle is equipped with a motor device having an engine and a motor, a first cooling device that has a first radiator and a first fan that cools the cooling water of the first radiator and cools one of the engine and the motor device; a second cooling device that has a second radiator and a second fan that cools the cooling water of the second radiator and cools the other of the engine and the motor device; A control device that controls the first fan and the second fan; A cooling system comprising: a freeze lock detection unit that detects a freeze lock of the first fan, When the freeze lock detection unit detects a freeze lock of the first fan, the control device stops driving the first fan and the second fan, the first fan cools the cooling water of the first radiator and also cools the refrigerant of the evaporator in an air conditioning device that performs air conditioning of a vehicle interior and includes a refrigeration cycle in which a refrigerant circulates through a compressor, a condenser, an expansion valve, and an evaporator in this order; the freeze lock detection unit determines whether or not the first fan is freeze locked based on a refrigerant pressure of the refrigerant between the condenser and the expansion valve. Cooling system.

2. 2. The cooling system of claim 1, the freeze lock detection unit determines whether or not the first fan is freeze-locked by comparing a first refrigerant pressure, which is the refrigerant pressure when the first fan is stopped, with a second refrigerant pressure, which is the refrigerant pressure when the first fan is driven. Cooling system.

3. 3. The cooling system according to claim 1, the freeze lock detection unit determines whether or not the first fan is freeze locked only when the outside air temperature is equal to or lower than a predetermined temperature. Cooling system.

4. A cooling system according to any one of claims 1 to 3, The first fan and the second fan are disposed in close proximity to each other. Cooling system.

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