JP2007182175A - Cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device capable of more effectively utilizing heat and contributing to improvement of fuel economy and reduction of emission of a vehicle. <P>SOLUTION: The cooling device 100 includes an electric pump 108 for circulating cooling water; an engine side flow passage 110 provided on an engine 2; a device side flow passage 112 for cooling an electric device 106, i.e., a device to be cooled; a heater core 114 having a flow passage 116 for cooling water; a by-pass flow passage 118 provided in parallel to the heater core 114; a radiator 122 provided in parallel to at least any one of the by-pass flow passage 118 and the heater core 114; and an integration valve 120. As a result of circulation by the electric pump 108, the integration valve 120 controls a ratio for dividingly flowing the cooling water flowing out from at least any one of the engine side flow passage 110 and the device side flow passage 112 to at least the heater core 114 and the by-pass passage 118. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cooling device, and more particularly to a cooling device mounted on a vehicle.

  In recent years, hybrid vehicles equipped with an engine and a motor as driving devices have attracted attention as environmentally friendly vehicles. Both power elements for driving the engine and the motor generate heat during operation.

  Some hybrid vehicles in practical use have two independent cooling systems, a cooling system for cooling the engine and a cooling system for cooling the periphery of the motor. However, the engine is not as good as it is cooled, and warm-up is required for efficient operation. For this reason, techniques for utilizing the heat generated around the motor to warm up the engine are being studied.

Japanese Patent Application Laid-Open No. 2004-218600 (Patent Document 1) includes a refrigerant circulation system that cools an engine and a refrigerant circulation system that cools a motor, and when the cooling water temperature on the engine side is low, the motor is driven by a three-way valve. A technique for promoting engine warm-up with cooling water that has been incorporated into the refrigerant circulation system on the side and deprived of heat from the motor is disclosed.
JP 2004-218600 A JP 2004-301041 A JP 2001-73765 A JP-A-7-253020 Japanese Utility Model Publication No. 5-69328

  Some hybrid vehicles perform traveling (EV traveling) by stopping the engine and traveling only by the motor when the state of charge of the battery is good. However, engine cooling water is also used as a heat source of a heater for heating. Therefore, if the engine is stopped for a long time, the room temperature decreases during heating, and the engine needs to be restarted. In addition, if the engine is stopped for a long time, the engine temperature falls from the appropriate temperature, and exhaust emission deteriorates. Therefore, there are driving conditions in which EV traveling for a long time cannot be performed and fuel consumption is deteriorated. For this reason, the current cooling device for hybrid vehicles still has room for optimization.

  An object of the present invention is to provide a cooling device that can use heat more effectively and contributes to improvement of fuel consumption of a vehicle and reduction of emissions.

  In summary, the present invention is a cooling device mounted on a vehicle, and the vehicle includes an internal combustion engine and a device to be cooled that requires cooling. The cooling device includes an electric pump that circulates the liquid medium, an engine-side flow path that cools the internal combustion engine, a device-side flow path that is arranged in parallel to the engine-side flow path and cools the device to be cooled, and a liquid A heater core having a medium flow path, a bypass flow path provided in parallel with the heater core, a radiator provided in parallel with at least one of the bypass flow path and the heater core, and an engine side flow path and device as a result of circulation by the electric pump And a control valve for controlling a ratio of flowing the liquid medium flowing out from at least one of the side flow paths into at least a heater core and a bypass flow path.

  Preferably, the control valve restricts the ratio of flowing the liquid medium to the bypass passage when there is a request for heating using the heater core when the internal combustion engine is stopped.

  Preferably, the engine side flow path and the apparatus side flow path are provided in parallel in the circulation path of the liquid medium, and both the outlet side is coupled to the control valve. The control valve selects the flow path so that the liquid medium flows through the bypass flow path, the engine-side flow path, and the apparatus-side flow path without going through the heater core when there is no heater request when the internal combustion engine is stopped. To do.

  Preferably, the control valve limits the ratio of the liquid medium flowing through the bypass flow path and the radiator when there is a heater request when the internal combustion engine is stopped.

  Preferably, the cooled device includes at least one of a vehicle propulsion motor, an inverter that drives the vehicle propulsion motor, and an auxiliary machine.

Preferably, the control valve is a valve that controls four or more flow paths.
Preferably, the control valve is connected to an outlet portion of the engine side passage, an outlet portion of the apparatus side passage, an inlet portion of the radiator, an inlet portion of the bypass passage, and an inlet portion of the heater core in a path through which the liquid medium circulates. Is done. The electric pump sucks the liquid medium discharged from the outlet of the radiator, the outlet of the bypass channel, and the outlet of the heater core, and discharges it toward the inlet of the engine side channel and the inlet of the device side channel. To do.

  According to the present invention, by realizing a cooling device that can more effectively use heat, it is possible to contribute to improving the fuel consumption of the vehicle and reducing emissions.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a schematic diagram showing a configuration of a hybrid vehicle 1 on which a cooling device of the present invention is mounted.

  Referring to FIG. 1, hybrid vehicle 1 includes front wheels 20R and 20L, rear wheels 22R and 22L, an engine 2, a planetary gear 16, a differential gear 18, and gears 4 and 6.

  The hybrid vehicle 1 further includes a battery B disposed behind the vehicle, a booster unit 32 that boosts DC power output from the battery B, an inverter 36 that transfers DC power between the booster unit 32, and the planetary gear 16 The motor generator MG1 coupled to the engine 2 via the main shaft and mainly generating electric power, and the motor generator MG2 whose rotation shaft is connected to the planetary gear 16 are included. Inverter 36 is connected to motor generators MG <b> 1 and MG <b> 2 and performs conversion between AC power and DC power from booster unit 32.

  Planetary gear 16 has first to third rotation shafts. The first rotation shaft is connected to engine 2, the second rotation shaft is connected to motor generator MG1, and the third rotation shaft is connected to motor generator MG2.

  A gear 4 is attached to the third rotating shaft, and the gear 4 drives the gear 6 to transmit power to the differential gear 18. The differential gear 18 transmits the power received from the gear 6 to the front wheels 20R and 20L, and transmits the rotational force of the front wheels 20R and 20L to the third rotating shaft of the planetary gear via the gears 6 and 4.

  Planetary gear 16 serves to divide the power between engine 2 and motor generators MG1, MG2. That is, if the rotation of two of the three rotation shafts of the planetary gear 16 is determined, the rotation of the remaining one rotation shaft is naturally determined. Accordingly, the vehicle speed is controlled by controlling the power generation amount of the motor generator MG1 and driving the motor generator MG2 while operating the engine 2 in the most efficient region, thereby realizing an overall energy efficient vehicle. Yes.

  A reduction gear that reduces the rotation of motor generator MG2 and transmits it to planetary gear PG may be further provided.

  Battery B, which is a DC power source, is composed of a secondary battery such as nickel metal hydride or lithium ion, for example, and supplies DC power to boost unit 32 and is charged by DC power from boost unit 32.

  Booster unit 32 boosts the DC voltage received from battery B and supplies the boosted DC voltage to inverter 36. Inverter 36 converts the supplied DC voltage into AC voltage, and drives and controls motor generator MG1 when the engine is started. Further, after the engine is started, AC power generated by motor generator MG1 is converted into DC by inverter 36, and converted to a voltage suitable for charging battery B by boosting unit 32, and battery B is charged.

  Inverter 36 drives motor generator MG2. Motor generator MG2 assists engine 2 to drive front wheels 20R and 20L. During braking, the motor generator performs a regenerative operation and converts the rotational energy of the wheels into electric energy. The obtained electric energy is returned to the battery B via the inverter 36 and the booster unit 32. Battery B is an assembled battery and includes a plurality of battery units B0 to Bn connected in series. System main relays 28 and 30 are provided between boost unit 32 and battery B, and the high voltage is cut off when the vehicle is not in operation.

  The control unit 14 controls the engine 2, the inverter 36, the booster unit 32, and the system main relays 28 and 30 in accordance with the driver's instructions and outputs from various sensors attached to the vehicle.

FIG. 2 is a block diagram showing a configuration of cooling device 100 according to the present embodiment.
Referring to FIG. 2, the hybrid vehicle includes an engine 2 and an electric device 106 that operates by receiving electric power and generates heat during operation and requires cooling. In FIG. 1, the motor generators MG1 and MG2, the control unit 14, the battery B, and the like including the booster unit 32 and the inverter 36 may correspond to the electric device 106 that generates heat during operation. That is, the electric device 106 includes at least one of a vehicle propulsion motor, an inverter that drives the vehicle propulsion motor, and an auxiliary machine. In addition, as an auxiliary machine, an electric air-conditioning compressor, an electric power steering pump, an alternator etc. are mentioned, for example.

  The cooling device 100 includes an electric pump 108 that circulates cooling water, an engine-side flow channel 110 provided in the engine 2, a device-side flow channel 112 that cools the electric device 106 that is a device to be cooled, and cooling water. A heater core 114 having a flow path 116, a bypass flow path 118 provided in parallel with the heater core 114, a radiator 122 provided in parallel with at least one of the bypass flow path 118 and the heater core 114, and an integrated valve 120 are included. The integrated valve 120 is a ratio in which cooling water flowing out from at least one of the engine-side flow path 110 and the apparatus-side flow path 112 as a result of circulation by the electric pump 108 is divided into at least the heater core 114 and the bypass flow path 118. To control.

  The integrated valve 120 is a valve that controls four or more flow paths, and is specifically a five-way valve. The integrated valve 120 includes an outlet portion of the engine-side passage 110, an outlet portion of the apparatus-side passage 112, an inlet portion of the radiator 122, an inlet portion of the bypass passage 118, and an inlet portion of the heater core 114 in the circulation path of the cooling water. The electric pump 108 sucks cooling water discharged from the outlet of the radiator 122, the outlet of the bypass passage 118, and the outlet of the heater core 114, and the inlet of the engine side passage 110 and the apparatus side. It discharges toward the inlet of the flow path 112.

  The integrated valve 120 can change which of the flow paths indicated by arrows A1 to A5 communicates according to the signal VSEL from the cooling system control unit 126. It is more preferable that the flow rate of each flow path communicated can be changed.

  The cooling system control unit 126 includes a signal HEON from the heating switch 128 operated by the driver, a temperature Te detected by the engine water temperature sensor 130 provided in the cooling water passage to detect the engine temperature, and an engine speed sensor 132. The signal VSEL is output on the basis of the detected engine speed Ne and the signal IGON that changes according to the operation of the ignition key switch. The cooling system control unit 126 may be an independent ECU (electronic control unit), or may be included in the control unit 14 of FIG.

  For example, when the vehicle is running in EV and the engine 2 is stopped, the electric pump 108 is driven, and the cooling water that has absorbed heat from the electric device 106 reaches the integrated valve 120 via the electric device 106. To do.

  When the engine 2 is stopped, the integrated valve 120 limits the rate at which the cooling water flows through the bypass passage 118 when there is a request for heating using the heater core 114.

  Further, the integrated valve 120 limits not only the bypass flow path 118 but also the ratio of the cooling water flowing to the radiator 122 when the heater 2 is requested when the engine 2 is stopped.

  By doing so, the heat generated in the electric device 106 is effectively used for heating, the temperature decrease of the heater core 114 is prevented, and the number of scenes where the engine 2 is restarted to increase the temperature of the heater core 114 is small. Become.

  The engine-side flow path 110 and the apparatus-side flow path 112 are provided in parallel in the cooling water circulation path, and both the outlet side is coupled to the integrated valve 120. The integrated valve 120 supplies cooling water to the bypass flow path 118, the engine side flow path 110, and the apparatus side flow path 112 without passing through the heater core 114 when the heater 2 is not requested when the engine 2 is stopped. The flow path is selected to flow.

  By doing so, it is avoided that heat is taken away by the heater core 114, and a part of the cooling water containing heat is introduced into the engine-side flow path 110, so that the warm-up is completed and the temperature becomes once suitable. In addition, the engine 2 can be avoided from being overcooled by traveling wind or natural heat radiation during traveling as much as possible, and the deterioration of emissions when the engine 2 is restarted is prevented. Further, it is possible to reduce the number of scenes in which the engine 2 has to be restarted for warm-up in order to avoid worsening of emissions.

  FIG. 3 is a flowchart showing a control structure of control performed by cooling system control unit 126 of FIG. The process of this flowchart is called from the main routine and executed whenever a predetermined time elapses or a predetermined condition is satisfied.

  Referring to FIGS. 2 and 3, when the process is started, cooling system control unit 126 detects whether or not the vehicle is in operation in step S <b> 1 based on the state of signal IGON. If IGON is in an active state, that is, if the vehicle is driving, the process proceeds to step S2, and if the vehicle is not driving, the process proceeds to step S12.

  In step S <b> 2, the cooling system control unit 126 determines whether or not the engine 2 is stopped based on the engine speed Ne detected by the engine speed sensor 132. If the engine is not stopped, the process proceeds to step S3, and if the engine 2 is stopped, the process proceeds to step S6.

  In step S3, the cooling system control unit 126 determines whether or not the temperature Te detected by the engine water temperature sensor 130 is lower than a predetermined temperature T0. If Te <T0 is satisfied, that is, if the engine 2 needs to be warmed up, the process proceeds to step S4. If not established, that is, if the engine 2 has been warmed up, the process proceeds to step S5.

  FIG. 4 is a diagram showing the flow path selected by the integrated valve 120 in step S4 of FIG.

  Referring to FIGS. 3 and 4, cooling system control unit 126 drives electric pump 108 to send the cooling water in the direction indicated by arrow A6. Then, the cooling water flows into the engine side channel 110 and the device side channel 112 connected in parallel.

  The cooling water that has flowed through the engine-side channel 110 in the direction indicated by the arrow A1 and the cooling water that has flowed through the device-side channel 112 in the direction indicated by the arrow A2 are merged by the integrated valve, and the bypass channel 118 is indicated by the arrow A5. Flow into. The integrated valve 120 restricts the flow rate of the flow paths indicated by arrows A3 and A4 or closes the flow paths. Then, the cooling water reaches the electric pump 108 again.

  In this way, when the engine is running and the engine temperature is low, the heater core 114 and the radiator 122 are excluded from the flow path, and the temperature of the cooling water rises quickly due to the heat generated in the engine 2. Thereby, the warm-up of the engine 2 is completed quickly.

  When the warm-up of the engine 2 is completed, the process proceeds from step S3 to step S5.

  FIG. 5 is a diagram showing the flow path selected by the integrated valve 120 in step S5 of FIG.

  Referring to FIGS. 3 and 5, cooling system control unit 126 drives electric pump 108 to send the cooling water in the direction indicated by arrow A6. Then, the cooling water flows into the engine side channel 110 and the device side channel 112 connected in parallel.

  The cooling water flowing in the direction indicated by the arrow A1 in the engine side flow path 110 and the cooling water flowing in the direction indicated by the arrow A2 in the apparatus side flow path 112 are merged by the integrated valve, and the radiator 122 is indicated as indicated by arrows A3 and A4. The flow path 124 and the flow path 116 of the heater core 114. The integrated valve 120 restricts the flow rate of the flow path indicated by the arrow A5 or closes the flow path. Then, the cooling water reaches the electric pump 108 again.

  Thus, after the warm-up of the engine 2 is completed, the heater core 114 and the radiator 122 are incorporated in the flow path, and the heat generated in the engine 2 is radiated. As a result, the engine 2 is kept at the optimum temperature.

  Referring to FIG. 3 again, when the process of step S4 or step S5 is completed, the process proceeds to step S12.

  When the process proceeds from step S2 to step S6, the hybrid vehicle is in an EV traveling state or the vehicle is stopped with the engine stopped due to a signal or the like.

  In step S <b> 6, the cooling system control unit 126 determines whether or not there is a heater request based on the signal HEON indicating the setting state of the heating switch 128. In the case where the heating switch 128 is for setting the temperature, the presence / absence of a heater request may be determined by comparing the current room temperature with the set temperature.

  If it is determined in step S6 that there is a heater request, the process proceeds to step S7. If it is determined that there is no heater request, the process proceeds to step S9.

  FIG. 6 is a diagram showing the flow path selected by the integrated valve 120 in step S7 of FIG.

  3 and 6, cooling system control unit 126 drives electric pump 108 to send the cooling water in the direction indicated by arrow A6. Then, the cooling water flows into the apparatus side flow path 112.

  The cooling water that has flowed in the direction indicated by the arrow A2 through the apparatus-side flow path 112 flows into the flow path 116 of the heater core 114 as indicated by the arrow A4 via the integrated valve. The integrated valve 120 restricts the flow rate of the flow paths indicated by arrows A1, A3, and A5, or closes the flow paths. And the cooling water which passed the flow path 116 of the heater core 114 reaches | attains the electric pump 108 again.

  In this way, when the temperature of the heater core 114 needs to be maintained while the engine is stopped such as EV traveling, the engine-side flow path 110 is excluded from the flow path, and the heater core 114 is heated by the heat generated in the electric device 106. Is maintained at a temperature T1 or higher necessary for heating.

  Note that the amount of heat generated by the electric device 106 may not be sufficient to maintain the heater core 114 at a temperature required for heating. Therefore, when step S7 is completed, step S8 is performed.

  In step S8, the cooling system control unit 126 determines whether or not the temperature Te near the engine detected by the engine water temperature sensor 130 is lower than the temperature T1 required for heating. This determination may be made using a temperature detected by a temperature sensor attached to the heater core 114 instead of the temperature Te near the engine.

  If Te <T1 is satisfied in step S8, the process proceeds to step S11. If Te <T1 is not satisfied, the process proceeds to step S12.

  In step S11, since the calorific value of the electric device 106 is not sufficient to maintain the heater core 114 at the temperature required for heating, the cooling device is operated so that the engine 2 is restarted and the cooling water temperature rises. Even in this case, the time until the engine 2 is restarted can be lengthened a little, and the time during which EV traveling is possible increases.

Next, a case where the process proceeds from step S6 to step S9 will be described.
FIG. 7 is a diagram showing the flow path selected by the integrated valve 120 in step S9 of FIG.

  Referring to FIGS. 3 and 7, cooling system control unit 126 drives electric pump 108 to send the cooling water in the direction indicated by arrow A6. Then, the cooling water flows into the engine side channel 110 and the device side channel 112 connected in parallel.

  The cooling water that has flowed through the engine-side channel 110 in the direction indicated by the arrow A1 and the cooling water that has flowed through the device-side channel 112 in the direction indicated by the arrow A2 are merged by the integrated valve, and the bypass channel 118 is indicated by the arrow A5. Flow into. The integrated valve 120 restricts the flow rate of the flow paths indicated by arrows A3 and A4 or closes the flow paths. Then, the cooling water reaches the electric pump 108 again.

  In this manner, when the engine is stopped and there is no heater request, the heater core 114 and the radiator 122 are excluded from the flow path, and the temperature of the cooling water is maintained to some extent by the heat generated by the electric device 106. The cooling water is introduced into the engine 2 so that the warm-up completion state of the engine 2 is maintained.

  Note that the amount of heat generated by the electric device 106 may not be sufficient for maintaining the warm-up completion state of the engine 2, and therefore, when the process of step S9 is completed, the process of step S10 is performed.

  In step S10, the cooling system control unit 126 determines whether or not the temperature Te near the engine detected by the engine water temperature sensor 130 is lower than the temperature T2 necessary for maintaining the warm-up completion state.

  If Te <T2 is satisfied in step S10, the process proceeds to step S11. If Te <T2 is not satisfied, the process proceeds to step S12.

  In step S11, since the amount of heat generated by the electric device 106 is not sufficient to maintain the warm-up completion state of the engine 2, the cooling device is operated so that the engine 2 is restarted and the cooling water temperature rises. Even if it is, the time until the engine 2 is restarted can be lengthened a little.

On the other hand, if the process proceeds to step S12, control is transferred to the main routine.
As described above, according to the cooling device of the present embodiment, the heat of the engine 2 and the heat of the electric device 106 are effectively used for heating and warming up of the engine 2. Therefore, it is possible to realize a vehicle in which energy is effectively used and fuel consumption is improved while realizing comfort of heating and reduction of emissions.

  In the present embodiment, the example in which the device side flow path for cooling the electric device is provided in parallel to the engine side flow path for cooling the engine 2 is shown, but the present invention is not limited to this. The apparatus to be cooled that is cooled in the apparatus-side flow path that is provided in parallel with the engine-side flow path may be a heat source such as an engine oil or transmission oil oil cooler or an EGR (Exhaust Gas Recirculation) cooler.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is the schematic which shows the structure of the hybrid vehicle 1 by which the cooling device of this invention is mounted. It is a block diagram which shows the structure of the cooling device 100 which concerns on this Embodiment. 3 is a flowchart showing a control structure of control performed by a cooling system control unit 126 of FIG. It is the figure which showed the flow path selected by the integrated valve 120 in step S4 of FIG. It is the figure which showed the flow path selected by the integrated valve 120 in step S5 of FIG. It is the figure which showed the flow path selected with the integrated valve 120 in step S7 of FIG. It is the figure which showed the flow path selected with the integrated valve 120 in step S9 of FIG.

Explanation of symbols

  1 Hybrid vehicle, 2 engine, 4, 6 gear, 14 control unit, 16 planetary gear, 18 differential gear, 20R, 20L front wheel, 22R, 22L rear wheel, 28, 30 system main relay, 32 boost unit, 36 inverter, 100 cooling Device, 106 Electric device, 108 Electric pump, 110 Engine side flow path, 112 Device side flow path, 114 Heater core, 116, 124 flow path, 118 Bypass flow path, 120 Integrated valve, 122 Radiator, 126 Cooling system control unit, 128 Heating switch, 130 Engine water temperature sensor, 132 Engine speed sensor, B battery, B0 to Bn battery unit, MG1, MG2 Motor generator, Ne Engine speed, PG planetary gear.

Claims (7)

A cooling device mounted on a vehicle,
The vehicle is
An internal combustion engine;
And a cooled device that requires cooling,
The cooling device is
An electric pump for circulating the liquid medium;
An engine side flow path for cooling the internal combustion engine;
An apparatus side flow path that is arranged in parallel to the engine side flow path and cools the cooled apparatus;
A heater core having a flow path for the liquid medium;
A bypass flow path provided in parallel with the heater core;
A radiator provided in parallel with at least one of the bypass flow path and the heater core;
Control for controlling the ratio of flowing the liquid medium flowing out from at least one of the engine-side flow path and the apparatus-side flow path into at least the heater core and the bypass flow path as a result of circulation by the electric pump A cooling device including a valve.   2. The cooling device according to claim 1, wherein the control valve restricts a ratio of flowing the liquid medium to the bypass passage when there is a request for heating using the heater core when the internal combustion engine is stopped. . The engine side flow path and the apparatus side flow path are provided in parallel in the circulation path of the liquid medium, and both outlet sides are coupled to the control valve,
The control valve is
When there is no heater request when the internal combustion engine is stopped, the liquid medium is allowed to flow through the bypass flow path, the engine side flow path, and the apparatus side flow path without passing through the heater core. The cooling device according to claim 1, wherein path selection is performed. The control valve is
The cooling device according to claim 1, wherein a ratio of flowing the liquid medium to the bypass flow path and the radiator is limited when there is a heater request when the internal combustion engine is stopped. The cooled device is
The cooling device according to claim 1, comprising at least one of a vehicle propulsion motor, an inverter that drives the vehicle propulsion motor, and an auxiliary machine.   The cooling device according to claim 1, wherein the control valve is a valve that controls four or more flow paths. The control valve includes an outlet portion of the engine-side flow passage, an outlet portion of the apparatus-side flow passage, an inlet portion of the radiator, an inlet portion of the bypass flow passage, and an inlet of the heater core in a path through which the liquid medium circulates. Connected to the
The electric pump sucks the liquid medium discharged from the outlet of the radiator, the outlet of the bypass channel, and the outlet of the heater core, and connects the inlet of the engine side channel and the device side channel. The cooling device according to claim 1, wherein the cooling device discharges toward the inlet portion.

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