JP2014204576A - Cooling system of electrical apparatus for driving vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling system of an electrical apparatus for driving a vehicle capable of suppressing decline of cooling performance for cooling the electrical apparatus for driving the vehicle, when a component of a refrigerant circulation passage is broken by collision of the vehicle.SOLUTION: A cooling system 10 includes: a refrigerant circulation passage 12 through which a refrigerant is circulated; a cooler 22 provided on the refrigerant circulation passage 12, for cooling an electrical apparatus 14 for driving a vehicle; a first valve 34 and a second valve 38 provided on the nearest upstream side and on the nearest downstream side of the cooler 22, on the refrigerant circulation passage 12; and a control device 80 for closing the first valve 34 and the second valve 38, when collision of a vehicle is detected.

Description

  The present invention relates to a cooling system for an electric device for driving a vehicle mounted on a vehicle, and particularly relates to suppression of a decrease in cooling performance of the electric device for driving a vehicle at the time of a vehicle collision.

  Patent Document 1 discloses the presence or absence of occurrence of abnormality in the refrigerant circulation path for circulating the coolant based on the temperature detected by the liquid temperature sensor provided in the vicinity of the coolant inlet of the inverter in the cooling system for the electric device for driving the vehicle. It is described to judge.

  Patent Document 2 describes that in a cooling system for an electric device for driving a vehicle, an electric device cooler is incorporated between a refrigerant outlet of a condenser for an air conditioner and a refrigerant inlet of an expansion valve.

  In Patent Document 3, in a cooling device including an evaporator for a vehicle air conditioner, a first capacitor, and a second capacitor, a motor generator for driving the vehicle between the refrigerant outlet of the first capacitor and the refrigerant inlet of the second capacitor; Incorporation of a cooling unit including an inverter is described.

JP 2008-256313 A JP 2011-110916 A JP2012-140060A

  In the cooling system described in Patent Document 1, abnormality in the refrigerant circuit is determined based on a change in the temperature of the refrigerant. Even if a component of the refrigerant circuit is damaged at the time of a light vehicle collision, until the temperature change of the refrigerant occurs. Abnormality cannot be judged including the damage. For this reason, it takes time to detect the abnormality, and there is a possibility that the refrigerant leaks from the damaged portion before the abnormality detection. For example, when a highly volatile refrigerant is used as the refrigerant, the refrigerant in the refrigerant circuit may be lost due to evaporation before the abnormality detection of the components of the refrigerant circuit. When the refrigerant leaks from the refrigerant circuit, the cooling performance for cooling the vehicle drive electric device is lowered. When this cooling performance is lowered, the vehicle running performance may be lowered. Patent Document 1 to Patent Document 3 do not disclose means for solving such inconvenience.

  An object of the present invention is to realize a cooling system for an electric device for driving a vehicle that can suppress a decrease in cooling performance for cooling the electric device for driving the vehicle when a component of the refrigerant circuit is damaged due to a collision of the vehicle. That is.

  A cooling system for an electric device for driving a vehicle according to the present invention is a cooling system for an electric device for driving a vehicle mounted on a vehicle, and is provided in the refrigerant circulation path through which the refrigerant circulates and the vehicle. When a collision between a cooler that cools the electric drive device, two valves provided on the most upstream side and the most downstream side of the cooler in the refrigerant circuit, and a vehicle collision is detected, the two And a control device for closing the valve. Note that “nearest upstream” and “nearest downstream” mean that neither another valve nor a branch flow path is arranged between the upstream side or downstream side of the cooler and the valve.

  According to the above configuration, when the collision of the vehicle is detected, the valves on both sides of the cooler of the vehicle drive electric device are closed, so that the refrigerant amount in the cooler can be easily maintained. For this reason, when the component of a refrigerant circuit is damaged by the collision of a vehicle, the fall of the cooling performance of the electric device for vehicle drive can be suppressed.

  In the cooling system for an electric device for driving a vehicle according to the present invention, preferably, a first condenser and a second condenser provided in the refrigerant circulation path are provided, and the two valves are connected to an outlet of the first condenser and the cooling condenser. A first valve provided in the refrigerant flow path between the cooler and a second valve provided in the refrigerant flow path between the cooler and the inlet of the second condenser.

  According to the above configuration, since the two condensers are provided in the refrigerant circulation path, it is possible to suppress the cooling performance of the cooler from being deteriorated even when cooling parts other than the cooler in addition to the cooler. Even if damage occurs, the amount of refrigerant in the cooler can be maintained by closing the two valves.

  In the cooling system for an electric device for driving a vehicle according to the present invention, preferably, the first valve includes a first port (1), a second port (2), a third port (3), and a fourth port (4). ), And the refrigerant circuit includes the cooler, the second valve, the second capacitor, the third port (3), the fourth port (4), the first capacitor, A route of the first port (1) and the second port (2) is included.

  According to the above configuration, in the case of the internal connection of the first port (1) and the second port (2) of the first valve and the internal connection of the third port (3) and the fourth port (4), the cooler , The second valve, the second condenser, the third port (3), the fourth port (4), the first condenser, the first port (1), the second port (2), and the refrigerant in which the refrigerant circulates in this order. When a circulation path is formed and the internal connection of the first port (1) and the fourth port (4) of the first valve and the internal connection of the second port (2) and the third port (3), the cooler , The second valve, the second condenser, the third port (3), the second port (2), the first refrigerant circulation path through which the refrigerant circulates in this order, the first condenser, the first port (1), the second A 4-port (4) and a second refrigerant circulation path through which the refrigerant circulates are formed in the order of the first condenser.

  In the cooling system for an electric device for driving a vehicle according to the present invention, preferably, the pressure provided in the refrigerant flow path on the first capacitor side connected to the fourth port (4) and the first port (1). A temperature sensor provided in a refrigerant flow path on the cooler side connected to the second port (2) and the third port (3), wherein the refrigerant is of a vapor compression refrigeration cycle type. An air-conditioning refrigerant, wherein the control device detects a vehicle collision, and after the first valve and the second valve are closed, the detected pressure of the pressure sensor is lower than a predetermined pressure; and When the temperature detected by the temperature sensor is equal to or higher than a predetermined temperature, the second valve is opened, and the first valve is connected to the first port (1) and the fourth port (4), and The second port (2) and the third port The refrigerant is circulated in the order of the cooler, the second valve, the second condenser, the third port (3), the second port (2), and the cooler. Then, a first refrigerant circulation path that is cut off from the first capacitor is formed.

  According to the above configuration, when there is an abnormality in the flow path component on the first capacitor side due to a vehicle collision, but there is no abnormality in the flow path component on the cooler side, the abnormal position is identified as the first refrigerant circulation on the cooler side. Cooling of the electric device for driving the vehicle can be promoted by circulating the refrigerant in the first refrigerant circulation path while being separated from the road.

  According to the cooling system for an electric device for driving a vehicle of the present invention, it is possible to suppress a decrease in cooling performance for cooling the electric device for driving the vehicle when a component of the refrigerant circuit is damaged due to a vehicle collision.

It is a figure which shows a refrigerant circuit and a control apparatus in the cooling system of the electric equipment for vehicle drive of embodiment of this invention. In the refrigerant circuit of FIG. 1, it is a schematic diagram of the refrigerant circuit formed including the internal coupling | bonding of each port of a four-way valve. It is a figure which shows a mode that the refrigerant | coolant circulation path of FIG. 1 is isolate | separated into two refrigerant | coolant circulation paths by intense heat determination. 2 is a flowchart showing normal time control and collision time control in the cooling system of FIG. 1. In the refrigerant circuit of FIG. 1, it is a figure which shows the valve closed state when the 2nd capacitor | condenser is damaged at the time of a collision. In another example of an embodiment of the present invention, it is a flowchart which shows normal time control, control at the time of collision, and return control after a collision. In the configuration of FIG. 5, when refrigerant leakage occurs at the time of collision in each of the first capacitor side flow path and the second capacitor side flow path, changes in detected values of impact acceleration, refrigerant pressure, and refrigerant temperature over time are changed. FIG. In another example of FIG. 6, it is a figure which shows the valve closed state when the 1st capacitor | condenser is damaged at the time of a collision. In FIG. 8, it is a figure which shows a mode that the 1st refrigerant circuit cut off from the 1st capacitor | condenser side is formed by the return control after a collision. It is a flowchart which shows normal time control, control at the time of collision, and return control after collision in 2nd example of another example of embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, the case where the vehicle on which the vehicle drive electrical device is mounted is a hybrid vehicle on which the engine and the travel motor are mounted will be described. Good. For example, it may be a fuel cell vehicle or an electric vehicle. In addition, you may use the motor generator which has the function of both a motor and a generator as a motor for driving | running | working. In the following description, like reference numerals denote like elements in all drawings.

  FIG. 1 shows a refrigerant circulation path 12 and a control device 80 in the cooling system 10 of the vehicle drive electric device 14 of the present embodiment. The cooling system 10 cools the vehicle drive electric device 14 with a vapor compression refrigeration cycle type air-conditioning refrigerant so that the vehicle drive electric device 14 called a PCU mounted on the hybrid vehicle can be cooled and the vehicle interior air conditioning can be performed. To do. An alternative chlorofluorocarbon can be used as the refrigerant. In FIG. 1, a pressure sensor 72 and a refrigerant temperature sensor 74 used in another example of FIGS. 8 to 10 described later are indicated by broken lines. Hereinafter, the vehicle drive electrical device 14 is referred to as “PCU 14”. First, the PCU 14 will be described.

  The PCU 14 includes an inverter 16, a DC / DC converter 18, and a motor control device 20 for driving a travel motor (not shown) for driving the vehicle. The DC / DC converter 18 is connected between a battery (not shown) and the inverter 16, boosts the DC voltage of the battery, and supplies the boosted voltage to the inverter 16. The inverter 16 converts the DC voltage supplied from the DC / DC converter 18 into a three-phase AC voltage, and supplies the driving motor for driving. The motor control device 20 is controlled by a control device 80 which will be described later, and controls the driving of the traveling motor via the inverter 16 and the DC / DC converter 18. Since the inverter 16 and the DC / DC converter 18 generate heat during use, the PCU 14 is cooled by a cooler 22 described later. The PCU 14 may be provided integrally with a transaxle (not shown) including a traveling motor.

  The first valve 34 is an electromagnetically switched four-way valve having a first port 1, a second port 2, a third port 3 and a fourth port 4. The second valve 38 is an electromagnetic switching type on-off valve. The refrigerant circuit 12 includes a path of the cooler 22, the second valve 38, the second capacitor 28, the third port 3, the fourth port 4, the first capacitor 26, the first port 1 and the second port 2. The first capacitor 26 is called an air conditioning capacitor, and the second capacitor 28 is called a cooler capacitor.

  The first valve 34 and the second valve 38 are provided in the refrigerant circulation path 12 on the immediate upstream side and the immediate downstream side of the cooler 22. The first valve 34 includes a first refrigerant passage 30 between the outlet P1a of the first condenser 26 and the cooler 22, and a second part between the outlet P2a of the second condenser 28 and the inlet P1b of the first condenser 26. It is provided in common with the refrigerant flow path 32.

  The first refrigerant channel 30 includes pipes 40a and 40b. The second refrigerant flow path 32 includes a pipe 42a, a liquid storage tank 48, a refrigerant pump 50, pipes 42b and 42c, an expansion valve 56, a pipe 42d, an evaporator 60, a pipe 42e, a compressor 58, and a pipe 42f.

  The second valve 38 is provided in the third refrigerant flow path 33 between the cooler 22 and the inlet P <b> 2 b of the second condenser 28. The third refrigerant channel 33 includes pipes 43a and 43b. With this configuration, by reducing the first valve 34 and the second valve 38 when a vehicle collision is detected, it is possible to suppress a decrease in the refrigerant amount inside the cooler 22. This will be described in detail later.

  In the first valve 34, switching of the internal coupling of the ports 1, 2, 3, 4 is controlled by a control device 80 described later. More specifically, as shown in FIG. 2, the first valve 34 can be switched between a normal position indicated by a solid line position of the valve element 94 and a flow path separation position indicated by a broken line position of the valve element 94. is there.

  In the normal position of the first valve 34, as shown in FIGS. 1 and 2, the first port 1 and the second port 2 are internally coupled, and the third port 3 and the fourth port 4 are internally coupled. On the other hand, in the flow path separation position of the first valve 34 in which the valve element 94 in FIG. 2 is at the broken line position, the internal connection of the first port 1 and the fourth port 4 and the internal connection of the second port 2 and the third port 3 are performed. It becomes. When the control signal is transmitted from the control device 80 to an actuator (not shown), the actuator is driven, and the valve body 94 is rotated by the actuator, whereby the first valve 34 is switched. The normal refrigerant circulation path 12 (FIG. 1) is formed at the normal position of the first valve 34, and at the flow path separation position of the first valve 34, as shown in FIG. A refrigerant circulation path 44 and a second refrigerant circulation path 46 are formed. This will be described in detail later.

  The first valve 34 is controlled by the control device 80 (FIG. 1), and each port 1, 2, 3, 4 is blocked from any other port inside, as indicated by a dashed line in FIG. It is also possible to switch to a closed valve state. In FIG. 5, the state where the first valve 34 indicates X inside the circle is a closed valve state. The first valve 34 is not limited to a rotary four-way valve that switches the internal coupling of the ports by the rotation of the valve element 94 as shown in FIG. As long as it has a structure that can be switched to a shut-off valve closed state, it may be a spool type four-way valve that switches the internal coupling of the ports by moving the spool.

  The liquid storage tank 48 is connected to the outlet P2a of the second condenser 28 by a pipe 42a, and stores the liquid refrigerant flowing from the second condenser 28. The refrigerant pump 50 is integrally connected to the outlet of the liquid storage tank 48 and is driven by a motor or engine (not shown) as a power source, and the driving is controlled by a control device 80 described later. The refrigerant pump 50 sends the liquid refrigerant sucked from the liquid storage tank 48 to the expansion valve 56 during driving. The refrigerant pump 50 may be connected to the liquid storage tank 48 via a pipe. The expansion valve 56 sends the decompressed liquid refrigerant to the evaporator 60.

  The evaporator 60 includes a plurality of tubes and fins provided between the tubes, and allows the low-temperature liquid refrigerant flowing from the expansion valve 56 to pass through the internal flow path inside the tubes. An air-conditioning blower 62 is provided in an air-conditioning duct in which the evaporator 60 is disposed, and air passes outside the evaporator 60 by driving the air-conditioning blower 62. The evaporator 60 exchanges heat between the air passing outside and the liquid refrigerant flowing through the internal flow path. The air that has passed through the outside of the evaporator 60 is blown into the passenger compartment as cooling air to cool the passenger compartment. The liquid refrigerant flowing inside the evaporator 60 is vaporized by heat exchange to become a gaseous refrigerant. An air conditioning unit 54 is formed by the evaporator 60 and the expansion valve 56.

  The compressor 58 is driven by using a motor or an engine (not shown) as a power source, and the driving is controlled by a control device 80 described later. The compressor 58 sucks and compresses the gaseous refrigerant flowing from the evaporator 60 during driving, and discharges the gaseous refrigerant.

  The first capacitor 26 is arranged on the front side of the vehicle so as to be able to capture the traveling wind, and includes a capacitor body 64 and a supercooling unit 66 having a plurality of tubes and fins provided between the tubes, It includes a receiver 68 and a liquid level gauge 70 attached to the cooling unit 66. The condenser main body 64 passes the high-temperature gaseous refrigerant discharged from the compressor 58 and sent from the inlet P1b through the internal flow path inside the tube, and performs heat exchange between the gaseous refrigerant and the air passing outside. Make it. In this case, the gaseous refrigerant flowing in the condenser main body 64 is condensed by exchanging heat with the air flowing outside and becomes a low-temperature liquid refrigerant. The liquid refrigerant flowing out from the outlet of the capacitor body 64 is separated into a liquid refrigerant and a gas refrigerant by the receiver 68, and only the liquid refrigerant passes through the supercooling unit 66.

  The supercooling unit 66 allows the liquid refrigerant to pass through the internal flow path inside the tube and exchange heat between the liquid refrigerant and the air passing outside. In this case, the temperature of the liquid refrigerant further decreases. The outlet P1a of the supercooling unit 66 is connected to the first port 1 of the first valve 34 by a pipe 40a. The liquid refrigerant that has flowed out of the outlet P1a of the supercooling section 66 flows out to the first valve 34. The level gauge 70 has a confirmation unit that can visually confirm the amount of liquid refrigerant. The second port 2 of the first valve 34 is connected to the cooler 22 by a pipe 40b.

  The cooler 22 cools the entire cooler 22 with a low-temperature liquid refrigerant flowing through the internal flow path, and cools the PCU 14 adjacent to the cooler 22. The cooler 22 may have an internal flow path provided so as to pass through the inside of the case that accommodates the PCU 14, and may be formed so as to cool the components of the PCU 14 with a refrigerant flowing through the internal flow path. The cooler 22 may be formed to cool not only the PCU 14 but also a traveling motor disposed in the vicinity of the PCU 14.

  The second valve 38 is an electromagnetic valve that is provided on the immediate downstream side of the cooler 22 and is controlled to be opened and closed by the control device 80, and can be switched in two stages of opening and closing. When the triangle representing the second valve 38 is white as shown in FIG. 1, the second valve 38 is in the open state, and when the triangle of the second valve 38 is black as shown in FIG. Is closed. Note that the first valve 34 and the second valve 38 are preferably arranged close to the cooler 22 in terms of distance, but piping between the cooler 22 and the first valve 34 and the second valve 38 is preferable. If 40b and 43a are arrange | positioned in the vehicle interior space which is hard to be crushed at the time of a vehicle collision, it will not be limited to the structure close | similar to the cooler 22 in distance.

  The second capacitor 28 is arranged on the front side of the vehicle so as to be able to capture the traveling wind. For example, the 2nd capacitor | condenser 28 is arrange | positioned with the 1st capacitor | condenser 26 at the further front side of the radiator for engine cooling which is arrange | positioned at the front side of the cooler 22 and is not shown.

  The second capacitor 28 includes a capacitor main body 75 and a supercooling unit 76 including a plurality of tubes and fins provided between the tubes, and a receiver 77 and a liquid level gauge 78 attached to the capacitor main body 75 and the supercooling unit 76. Including. The condenser body 75 allows the liquid refrigerant flowing from the second valve 38 to pass through the internal flow path inside the tube, and exchanges heat between the liquid refrigerant and the air passing outside. In this case, the temperature of the liquid refrigerant flowing inside the condenser main body 75 and the supercooling unit 76 is lowered by exchanging heat with the air flowing outside. When the temperature of the refrigerant that has passed through the first capacitor 26 increases due to passing through the cooler 22, the temperature is decreased again by the second capacitor 28. The configurations of the receiver 77 and the liquid level gauge 78 are the same as those of the first capacitor 26. Further, the first capacitor 26 and the second capacitor 28 may have the same cooling performance. On the other hand, the first condenser 26 is used exclusively for air conditioning that requires higher cooling performance than the cooling of the PCU 14 by switching the first valve 34 to the flow path separation position as will be described later. The cooling performance may be higher than the cooling performance of the second capacitor 28.

  The collision acceleration sensor 24 is fixed to the cooler 22 and forms a vehicle collision detection unit together with a vehicle collision determination unit 82 included in the control device 80. The collision acceleration sensor 24 uses the acceleration generated by the sensor component as an impact acceleration and transmits a signal representing the detected value to the control device 80. The collision acceleration sensor 24 is not limited to the configuration fixed to the cooler 22, and the collision acceleration sensor 24 may be fixed to any component as long as it is a component fixed to the vehicle body.

  The indoor temperature sensor 92 detects the temperature in the vehicle interior and transmits a signal representing the detected temperature to the control device 80.

  The control device 80 is also called an HV controller, and includes a microcomputer having a CPU and a memory. The control device 80 receives a signal representing a pedal operation amount from an accelerator pedal sensor (not shown), and receives a plurality of signals including a signal representing a detected value of the vehicle speed from a vehicle speed sensor (not shown), and the motor control device 20 and an engine (not shown). The control device is controlled to control the operation of the traveling motor and the engine. The control device 80 may be a control device different from the control device that controls the operation of the traveling motor and the engine.

  The control device 80 includes a vehicle collision determination unit 82 and a valve control unit 84. The vehicle collision determination unit 82 determines that the vehicle has collided with some object (not shown) and has received a predetermined impact when the impact acceleration detected by the collision acceleration sensor 24 is equal to or greater than a predetermined value. Is detected, and the collision detection is output to the valve controller 84.

  When the vehicle collision determination unit 82 detects a vehicle collision, the valve control unit 84 closes the first valve 34 and the second valve 38 as shown in FIG.

  The valve control unit 84 also has a function of determining that the temperature is extremely hot when the temperature detected by the indoor temperature sensor 92 is equal to or higher than a predetermined temperature, and switching the first valve 34 to the flow path separation switching position in FIG. Have.

  According to the cooling system 10 described above, as shown by the solid line in FIG. 2, the first valve 34 is in the normal position, and the refrigerant 58 is driven in the direction indicated by the solid line arrow in FIG. 1 by driving the compressor 58 and the refrigerant pump 50. The refrigerant circulates in the circulation path 12. In this case, the refrigerant is the cooler 22, the second valve 38, the second condenser 28, the liquid storage tank 48, the refrigerant pump 50, the third port 3, the fourth port 4, the expansion valve 56, the evaporator 60, the first valve 34, A refrigerant circulation path 12 that circulates in the order of the compressor 58, the first condenser 26, the first port 1 of the first valve 34, the second port 2, and the cooler 22 is formed. In this case, the refrigerant changes phase to a gas phase, a liquid phase, or a gas-liquid mixed state.

  On the other hand, when it is determined that the heat is detected from the temperature detected by the indoor temperature sensor 92, the valve element 94 is in a broken line position as shown in FIG. In this case, as shown in FIG. 3, the first refrigerant circulation path 44 and the second refrigerant circulation path 46 are formed. In the first refrigerant circulation path 44, as indicated by an arrow α in FIG. 3, the refrigerant is the third of the cooler 22, the second valve 38, the second condenser 28, the liquid storage tank 48, the refrigerant pump 50, and the first valve 34. It circulates in order of the port 3, the 2nd port 2, and the cooler 22. In the second refrigerant circulation path 46, as indicated by the arrow β, the refrigerant is the first condenser 26, the first port 1, the fourth port 4, the expansion valve 56, the evaporator 60, the compressor 58, the first condenser 34 of the first valve 34. It circulates in order of 26. In this case, the refrigerant pump 50 circulates the refrigerant in the first refrigerant circuit 44, and the compressor 58 circulates the refrigerant in the second refrigerant circuit 46.

  Next, a method for performing the normal control and the collision control using the cooling system 10 will be described with reference to the flowchart shown in FIG. The control method shown in FIG. 4 may be executed by a program stored in the control device 80. First, in step S10 (hereinafter, the step is simply referred to as S), the vehicle collision determination unit 82 sets an initial value 0 to “maximum G” representing the maximum impact acceleration up to this time. In S <b> 12, the impact acceleration detected by the collision acceleration sensor 24 is input to the control device 80.

  The vehicle collision determination unit 82 determines whether or not the maximum G is less than the current G in S14. “Current G” is the impact acceleration detected in the current control cycle. If the determination result in S14 is negative, the process proceeds to S18. On the other hand, when the determination result of S14 is affirmative, since the current G exceeds the maximum G, the current G is updated with the larger maximum G. On the other hand, if the determination result in S14 is negative, the maximum G is maintained because G is currently not more than the maximum G. Therefore, the maximum impact acceleration up to this time is set as the maximum G.

  In S18, the vehicle collision determination unit 82 determines whether or not the maximum G is less than the predetermined value A. If the determination result is affirmative, it is determined that there is no vehicle collision (S19), and S20 to S26. Perform normal control. In S20, the second valve 38 is opened, and in S22, the first valve 34 is in the normal position. Subsequently, the compressor 58 is driven (S24), and the refrigerant pump 50 is driven (S26).

  On the other hand, if the determination result in S18 is negative, the maximum G is equal to or greater than the predetermined value A, it is determined that a vehicle collision has been detected (S27), and the collision control from S28 to S34 is performed. In S28, the second valve 38 is closed, and in S30, the first valve 34 is closed. Next, the drive of the compressor is stopped (S32), and the drive of the refrigerant pump is also stopped (S34). After the process of S26 or S34, the process returns to S12 and the above process is repeated.

  According to the cooling system 10 described above, the first valve 34 and the second valve 38 on both sides of the cooler 22 that cools the PCU 14 are closed when a vehicle collision is detected by the vehicle collision detection means. It is easy to maintain the amount of refrigerant in the vessel 22. For this reason, when the component of the refrigerant circuit 12 is damaged by the collision of the vehicle, it is possible to suppress a decrease in cooling performance for cooling the PCU 14. For this reason, the fall of vehicle running performance can be suppressed. On the other hand, when the PCU 14 is not cooled to a desired state, the control device 80 can limit the output for protecting the parts. In this case, however, the running performance of the vehicle may be greatly reduced. In this invention, since the fall of the cooling performance of PCU14 can be suppressed, the fall of the driving performance including the acceleration performance of a vehicle can be suppressed.

  FIG. 5 shows a valve closed state in the refrigerant circulation path 12 when the second capacitor 28 is damaged at the time of a vehicle collision. In this case, since the first valve 34 and the second valve 38 on both sides of the cooler 22 are quickly closed by detection of the vehicle collision, the cooler is in spite of the damage of the second capacitor 28. The refrigerant is prevented from leaking from the inside through the damaged portion, and the amount of refrigerant in the cooler 22 is easily maintained. In the event of a vehicle collision, in addition to the case of FIG. 5, when the first capacitor 26 is damaged as shown in FIG. 8 described later, or other than between the first valve 34 and the second valve 38 across the cooler 22. Although damage may occur in the piping, the amount of refrigerant in the cooler 22 can be easily maintained even in this case.

  In addition, the abnormality of the components of the refrigerant circuit 12 is determined from the detection value of the temperature sensor that detects the refrigerant temperature as the refrigerant state, and the valves on both sides of the cooler 22 are closed when the abnormality is determined. Unlike the case, in the present invention, the first valve 34 and the second valve 38 can be closed before the abnormality of the refrigerant state is detected by the sensor. For this reason, when the component of the refrigerant circuit 12 is damaged by the collision of the vehicle, it is possible to quickly suppress the deterioration of the cooling performance of the PCU 14. Therefore, when there is no problem in the traveling parts including the power source including the engine and the traveling motor, the power transmission unit transmitting the power of the power source to the wheels, and the wheel supporting unit due to a slight collision. In addition, there is a high possibility that the vehicle can run on its own. Moreover, since the discharge | release of the refrigerant | coolant from the inside of the cooler 22 can be suppressed, when a refrigerant | coolant is a global warming effect gas, the bad influence to the atmosphere of the gas can be suppressed.

  In addition, since the first condenser 26 and the second condenser 28 are provided in the refrigerant circulation path 12, the evaporator 60 is cooled as a component other than the cooler 22 in addition to the cooler 22, and the air passing through the evaporator 60 is cooled. However, the cooling performance decline of the cooler 22 can be suppressed. Moreover, even if any of the two capacitors 26 and 28 is damaged due to a collision, the amount of refrigerant in the cooler 22 can be maintained by closing the first valve 34 and the second valve 38.

  Further, according to the control method described in the flowchart of FIG. 4, the maximum G is updated to the current G only when the impact acceleration detected this time by the collision acceleration sensor 24 exceeds the maximum G before the previous time. When G exceeds a predetermined value A for collision detection, the first valve 34 and the second valve 38 on both sides of the cooler 22 are kept closed. For this reason, the refrigerant inside the cooler 22 can be maintained even after the impact acceleration is reduced. Note that the initial setting of the maximum G may be performed by reset means including a reset switch (not shown) provided in the vehicle. In this case, after the breakage of the component parts of the refrigerant circuit 12 is repaired at the repair shop, the initial setting of the maximum G can be performed by operating the reset means. The same applies to the case of minimum T, minimum P, maximum ΔT, and maximum ΔP described later.

  FIG. 6 is a flowchart illustrating normal time control, collision time control, and post-collision return control in another example of the embodiment of the present invention. In this example, the pressure sensor 72 and the refrigerant temperature sensor 74 are provided in the refrigerant circulation path 12 in the configuration shown in FIGS.

  The pressure sensor 72 is provided in the pipe 42 c of the second refrigerant channel 32 in the refrigerant channel on the first capacitor 26 side connected to the fourth port 4 and the first port 1 of the first valve 34. The pressure sensor 72 detects the refrigerant pressure in the pipe 42 c and transmits a signal representing the detected pressure to the control device 80. The pressure sensor 72 is one of the pipes 42d, 42e, and 42f on the first capacitor 26 side of the first valve 34 of the second refrigerant flow path 32, or the pipe 40a of the first refrigerant flow path 30 other than the pipe 42c. May be provided.

  The refrigerant temperature sensor 74 is provided in the pipe 42 a of the second refrigerant flow path 32 in the refrigerant flow path on the cooler 22 side connected to the second port 2 and the third port 3 of the first valve 34. The refrigerant temperature sensor 74 detects the refrigerant temperature in the pipe 42 a and transmits a signal representing the detected temperature to the control device 80. The refrigerant temperature sensor 74 is provided on the pipe 40b of the first refrigerant flow path 30, the pipe 42b of the second refrigerant flow path 32, or the pipe 43a or the pipe 43b of the third refrigerant flow path 33 other than the pipe 42a. Also good.

  After the collision of the vehicle is detected and the first valve 34 and the second valve 38 are closed, the control device 80 reduces the detected pressure P of the pressure sensor 72 below the predetermined pressure C (P <C). In addition, when the detected temperature T of the refrigerant temperature sensor 74 is equal to or higher than the predetermined temperature B (T ≧ B), “post-collision return control” is executed. “Return control after collision” is a control in the case where an abnormality has occurred in the flow path component on the first capacitor 26 side, but no abnormality has occurred in the flow path component on the cooler 22 side. Opens the second valve 38 and switches the first valve 34 to the flow path separation switching position of FIG.

  With this configuration, as will be described in detail later, an abnormality has occurred in the flow path component on the first capacitor 26 side due to a vehicle collision, but no abnormality has occurred in the flow path component on the cooler 22 side. In addition, it is possible to promote the cooling of the PCU 14 by circulating the refrigerant in the first refrigerant circulation path 44 with the abnormality occurrence portion being separated from the cooler 22 side.

  Next, normal control, collision control, and post-collision return control will be described using the flowchart shown in FIG. First, in S40, the vehicle collision determination unit 82 sets initial values 0 to the maximum G up to the current time point, the minimum T up to the current time point, and the minimum P up to the current time point. “Minimum T” is the lowest value of the detected temperature T of the refrigerant temperature sensor 74. “Minimum P” is the minimum value of the detected pressure P of the pressure sensor 72.

  In S <b> 42, the control device 80 acquires acceleration, refrigerant temperature, and refrigerant pressure from the collision acceleration sensor 24, the refrigerant temperature sensor 74, and the pressure sensor 72. The detected values of the refrigerant temperature and the refrigerant pressure may be acquired by the control device 80 continuously for a few seconds as a preset period, and may be obtained by averaging each of the refrigerant temperature and the refrigerant pressure. The processing from S44 to S48 is the same as the processing from S14 to S18 in FIG. In S48, if the determination result is negative and the maximum G is greater than or equal to a predetermined value A, it is a case where a vehicle collision is detected, and therefore, control at the time of collision is performed (S50). This collision control process is the same as the process from S28 to S34 in FIG. On the other hand, if the determination result of S44 is affirmative, the process proceeds to S58.

  After the process of S50, it is determined in S52 whether or not the minimum T is larger than the current T. “Current T” is the refrigerant temperature detected in the current control cycle. If the determination result in S52 is negative, the process proceeds to S56. On the other hand, if the determination result in S52 is affirmative, since the current T is less than the minimum T, the current T is updated with a smaller minimum T. On the other hand, if the determination result in S52 is negative, the minimum T is maintained because the current T is equal to or greater than the minimum T.

  In S56, the valve control unit 84 determines whether or not the minimum T is greater than or equal to the predetermined value B. If the determination result is negative, the flow path on the second capacitor 28 side is the same as in the case of FIG. It is determined that the component is damaged, and the process returns to S42 in a state where the first valve 34 and the second valve 38 are maintained closed.

  The reason why this determination is made in S56 will be described. FIG. 7 shows the detection of the impact acceleration, the refrigerant pressure and the refrigerant temperature when the refrigerant leaks in the collision between the flow path on the second capacitor 28 side and the flow path on the first capacitor 26 side in the configuration of FIG. The time change of the value is shown. In this case, it is determined that a collision has occurred because the impact acceleration suddenly increases at time t1.

  Further, the refrigerant temperature rapidly decreases at time t2. This is because if the highly volatile air-conditioning refrigerant leaks from the flow path to the outside, vaporization of the refrigerant is promoted, so that the surroundings are cooled by absorption of the vaporization heat and the detected temperature decreases in a short time. For this reason, it is determined that a refrigerant leak has occurred due to a breakage in the flow path component on the second capacitor 28 side where the refrigerant temperature sensor 74 is disposed due to a temperature drop. In this case, it is possible to determine that the refrigerant has leaked when the refrigerant temperature is lower than the predetermined value B that is arbitrarily set in advance, the determination result of S56 of FIG. 6 is negative, and the minimum T is lower than the predetermined value B ( With the minimum T <B), it can be determined that the second capacitor 28 is damaged, and the first valve 34 and the second valve 38 are kept closed.

  Returning to FIG. 6, if the determination result is affirmative in S56, it is determined whether or not the minimum P is greater than the current P, which is the refrigerant pressure detected this time (S58), and if the determination result is negative. The process proceeds to S60. On the other hand, if the determination result in S58 is affirmative, since the current P is less than the minimum P in S59, the current P is updated with a smaller minimum P. On the other hand, when the current P is not less than the minimum P, the minimum P is maintained.

  In S60, the valve control unit 84 determines whether the minimum P is less than the predetermined value C. If the determination result is affirmative, the post-collision return control from S61 to S63 is performed. In this case, as shown in FIG. 8, the flow path component on the second capacitor 28 side is not damaged, but it is determined that the flow path component on the first capacitor 26 side is damaged and the refrigerant leaks. Is done. In the post-collision return control, the second valve 38 is opened in S61 of FIG. 6, and the first valve 34 is switched to the separation mode in FIG. In this case, the refrigerant circulation path 12 (FIG. 1) is separated by the first valve 34 into a flow path on the first condenser 26 side and a first refrigerant circulation path 44. Next, the refrigerant pump is driven in S63 of FIG. 6, and the refrigerant is circulated through the first refrigerant circulation path 44 as indicated by the solid line arrow in FIG.

  The reason why it is determined in S60 that the flow path component on the first capacitor 26 side is damaged will be described with reference to FIG. In FIG. 7, after a sudden increase in impact acceleration occurs at time t1, the refrigerant pressure rapidly decreases at time tA. The reason for this is that the flow path component on the first capacitor 26 side where the pressure sensor 72 is disposed is damaged and refrigerant leaks. In this case, it is possible to determine that the refrigerant has leaked when the refrigerant pressure is less than the predetermined value C set arbitrarily in advance, and the minimum P becomes less than the predetermined value C in the determination of S60 in FIG. 6 (minimum P <C Therefore, it can be determined that the first capacitor 26 is damaged. In S60 of k, it is a case where it is determined that there is no refrigerant leakage on the second capacitor 28 side by the determination using the temperature detected by the refrigerant temperature sensor 74 in S56, or a collision is not detected in S48. For this reason, the refrigerant is circulated through the first refrigerant circulation path 44 at the refrigerant flow path separation position of the first valve 34 as shown in FIG.

  On the other hand, if the determination result in S60 of FIG. 6 is negative, it is determined that no refrigerant leakage has occurred in any of the refrigerant circulation paths 12, so the normal time control from S64 to S70 is performed. This normal-time control is the same as S20 to S26, but in S66, the detected temperature of the indoor temperature sensor 92 (FIG. 1) is acquired by the control device 80 as the “first valve optional mode”, and according to the detected temperature. The first valve 34 is switched between the normal position (FIG. 1) and the flow path separation position (FIG. 3). After the processes of S63 and S70 in FIG. 6, the process returns to S42 and the above process is repeated.

  According to the cooling system 10 described above, there is an abnormality in the flow path component on the first condenser 26 side of the first valve 34 due to a vehicle collision as shown in FIG. When there is no, the 1st refrigerant circuit 44 by the side of cooler 22 can be intercepted from the 1st capacitor 26 side in which abnormality occurred. For this reason, it is possible to promote cooling of the PCU 14 by circulating the refrigerant through the first refrigerant circulation path 44 while the abnormal portion is separated from the first refrigerant circulation path 44. Other configurations and operations are the same as those in FIGS. 1 to 5 described above.

  FIG. 10 is a flowchart showing normal time control, collision time control, and post-collision return control in a second example of another example of the embodiment of the present invention. In the control device 80 of the present example, after the collision of the vehicle is detected and the first valve 34 and the second valve 38 are closed, the time change rate of the pressure drop detected by the pressure sensor 72 increases from a predetermined value. In addition, when the time change rate of the temperature decrease detected by the refrigerant temperature sensor 74 is equal to or less than a predetermined value, the “return control after collision” is executed. In the case of such a configuration as well, in the same manner as in the configurations of FIGS. 6 to 9 described above, in the state where the abnormality occurrence location where an abnormality has occurred due to a vehicle collision is separated from the first refrigerant circulation path 44 without any abnormality, It becomes possible to circulate the refrigerant in the circulation path 44.

  Next, normal control, collision control, and post-collision return control will be described using the flowchart shown in FIG. In this example, the refrigerant leakage is determined not by using the detected values of the temperature and pressure itself but by using the rate of change over time of the temperature and pressure drop. As shown in FIG. 7 above, when a refrigerant leak occurs in the refrigerant flow path, the rate of change over time of the respective decreases in the refrigerant temperature and the refrigerant pressure increases. In this example, the refrigerant leakage is determined based on the increase in the time change rate, and when it is determined that the refrigerant leakage has occurred, the control at the time of collision or the return control after the collision is performed.

  First, in S80 of FIG. 10, the vehicle collision determination unit 82 sets initial values 0 to the maximum G up to the current time, the maximum ΔT up to the current time, and the maximum ΔP up to the current time. “Maximum ΔT” is the maximum value of the time change rate of the temperature decrease detected by the refrigerant temperature sensor 74. “Maximum ΔP” is the maximum value of the time change rate of the pressure drop detected by the pressure sensor 72.

  S82 to S90 in FIG. 10 are the same as S42 to S50 in FIG. In S92, ΔT, which is the rate of change over time of the detected temperature drop of the refrigerant temperature sensor 74, is calculated from the change in the detected temperature T over a predetermined period set in advance. In S92, the detection unit T of the control device 80 may continuously acquire the detected temperature T as a preset period for several seconds, and the average of the time change rate of the decrease in the detected temperature T may be obtained as ΔT. . The processing from S94 to S96 is similar to the processing in which the minimum T in FIG. 6 is replaced with the maximum ΔT, the current T is replaced with the current ΔT, and the magnitude relationship is reversed. In S98, it is determined whether or not the maximum ΔT is equal to or less than the predetermined value Ba. If the determination result is negative, the maximum value of the time change rate of the temperature decrease is excessive, so the flow path on the second capacitor 28 side. It is determined that the component is damaged, and the process returns to S82 with the first valve 34 and the second valve 38 kept closed.

  If the determination result in S98 is affirmative, ΔP, which is a time change rate of the detected pressure drop of the pressure sensor 72, is calculated from the change in the detected pressure P in the predetermined period preset in S100. In S100, the calculation unit of the control device 80 may obtain the detected pressure P continuously for a few seconds as a preset period, and obtain an average of the time change rate of the decrease in the detected pressure P as ΔP. . The processing from S102 to S104 is the same as the processing in FIG. 6 in which the minimum P is replaced with the maximum ΔP, the current P is replaced with the current ΔP, and the magnitude relationship is reversed. In S106, it is determined whether or not the maximum ΔP exceeds a predetermined value Ca. If the determination result is affirmative, there is no damage in the flow path component on the second capacitor 28 side as shown in FIG. However, it is determined that the refrigerant is leaking due to the breakage of the flow path component on the first capacitor 26 side. In this case, return control after collision from S108 to S112 is performed.

  On the other hand, if the determination result in S106 is negative, normal control from S114 to S120 is performed. Other configurations and operations are the same as those in FIGS. 6 to 9 described above.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course. For example, a simple electromagnetic switching type on-off valve may be used as the first valve, and may be configured to be closed by the control device 80 upon collision detection.

  In the above description, the collision detection unit is formed by the collision acceleration sensor 24 and the vehicle collision determination unit 82. However, the collision detection unit has a function of detecting the occurrence of a collision when the detected impact acceleration is a predetermined value or more. You may form with the sensor which has. In this case, the detection signal of the sensor is input to the control device, and the control device closes the first valve 34 and the second valve 38 in response to detection of the occurrence of the collision.

  DESCRIPTION OF SYMBOLS 1 1st port, 2 2nd port, 3 3rd port, 4 4th port, 10 Cooling system, 12 Refrigerant circuit, 14 Vehicle drive electric equipment (PCU), 16 Inverter, 18 DC / DC converter, 20 Motor Control device, 22 cooler, 24 collision acceleration sensor, 26 first capacitor, 28 second capacitor, 30 first refrigerant flow path, 32 second refrigerant flow path, 33 third refrigerant flow path, 34 first valve, 38 first 2 valves, 40a, 40b piping, 42a-42f piping, 43a, 43b piping, 44 1st refrigerant circulation path, 46 2nd refrigerant circulation path, 48 liquid storage tank, 50 refrigerant pump, 54 air conditioning unit, 56 expansion valve, 58 Compressor, 60 evaporator, 62 Air conditioner blower, 64 Condenser body, 66 Supercooling section, 68 Receiver, 70 Liquid level gauge , 72 Pressure sensor, 74 Refrigerant temperature sensor, 75 Condenser body, 76 Supercooling section, 77 Receiver, 78 Level gauge, 80 Control device, 82 Vehicle collision determination section, 84 Valve control section, 92 Indoor temperature sensor, 94 Valve body .

Claims (4)

A cooling system for a vehicle driving electric device mounted on a vehicle,
A refrigerant circulation path through which the refrigerant circulates;
A cooler that is provided in the refrigerant circulation path and cools the electric device for driving the vehicle;
In the refrigerant circuit, two valves provided on the most upstream side and the most downstream side of the cooler;
A cooling system for an electric device for driving a vehicle, comprising: a control device that closes the two valves when a vehicle collision is detected. The cooling system for an electric device for driving a vehicle according to claim 1,
A first capacitor and a second capacitor provided in the refrigerant circuit;
The two valves include a first valve provided in a refrigerant flow path between the outlet of the first condenser and the cooler, and a refrigerant flow path between the cooler and the inlet of the second condenser. A cooling system for an electric device for driving a vehicle, characterized in that the second valve is provided. The vehicle drive electrical equipment cooling system according to claim 2,
The first valve is a four-way valve having a first port (1), a second port (2), a third port (3), and a fourth port (4);
The refrigerant circuit includes the cooler, the second valve, the second capacitor, the third port (3), the fourth port (4), the first capacitor, the first port (1), and A cooling system for an electric device for driving a vehicle, characterized by including a path of the second port (2). The vehicle drive electrical equipment cooling system according to claim 3,
A pressure sensor provided in the refrigerant passage on the first capacitor side connected to the fourth port (4) and the first port (1);
A temperature sensor provided in the refrigerant flow path on the cooler side connected to the second port (2) and the third port (3);
The refrigerant is a vapor compression refrigeration cycle type air conditioning refrigerant,
The control device detects a collision of a vehicle, and after the first valve and the second valve are closed, the detected pressure of the pressure sensor is lower than a predetermined pressure, and the temperature sensor detects When the temperature is equal to or higher than a predetermined temperature, the second valve is opened, and the first valve is connected to the internal connection of the first port (1) and the fourth port (4), and the second port (2 ) And the third port (3) are internally coupled to each other, and the cooler, the second valve, the second capacitor, the third port (3), the second port (2), and the cooler A cooling system for an electric device for driving a vehicle, characterized in that a refrigerant circulates in order and forms a first refrigerant circulation path that is cut off from the first capacitor.

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