JP5857899B2 - In-vehicle internal combustion engine cooling system - Google Patents

Description

  The present invention relates to a cooling system for an onboard internal combustion engine.

  2. Description of the Related Art Conventionally, a technique for heating hydraulic fluid of a transmission using heat of cooling water that cools a water-cooled internal combustion engine is known. For example, in the technique described in Patent Document 1, a heater core for heating, a heating device for heating hydraulic oil (oil warmer), and an electric motor that is driven independently from an internal combustion engine are provided in a circulation channel for circulating cooling water. And a bypass water channel that bypasses the heating device is provided on the downstream side of the heater core. As a result, it is possible to select a case where the hydraulic fluid of the transmission is preferentially heated by the heat of the cooling water and a case where the heating of the vehicle interior is preferentially performed. Specifically, when it is not necessary to heat the hydraulic fluid of the transmission, such as after the transmission is warmed up, the water pump is driven even when the internal combustion engine is in operation, and the heating device is bypassed for cooling. The water is circulated. Thereby, the fall of the circulating water amount to a heater core is prevented, and it is trying to improve the heating performance of a vehicle interior.

Japanese Patent Laid-Open No. 2001-263061

  However, in the above-described prior art, for example, even when the temperature of the hydraulic oil is low at the time of cold start of the internal combustion engine, if the heating request is generated, the heating request is given priority. Therefore, when the internal combustion engine is cold-started, the operating oil rises to the warm-up completion temperature, and the loss due to the operation of the transmission in the cold state is increased. Therefore, inconvenience for improving the fuel consumption of the internal combustion engine occurs.

  Moreover, in the control which switches on / off of a water pump, the result of whether the heating request | requirement has arisen is dominant. Therefore, for example, unless a heating request is generated, there is a problem that the cooling water cannot flow through the heating device while the internal combustion engine is stopped, and the hydraulic oil cannot be warmed.

  The present invention relates to a cooling system for an in-vehicle internal combustion engine capable of distributing an appropriate amount of cooling water to a cooling water path in a vehicle in which both a heating request and a hydraulic oil heating request can occur. The main purpose is to provide

  Hereinafter, means for solving the above-described problems and the effects thereof will be described.

In the present invention, the water pump (31) provided in the cooling water path (15) connected to the internal combustion engine (10) and driven separately from the internal combustion engine to distribute the cooling water to the cooling water path, A heater core (21) for heating a vehicle interior provided in the cooling water path; and a heating device (32) provided in the cooling water path for heating hydraulic oil for on-vehicle equipment by the cooling water. An amount of cooling water corresponding to the operating state is circulated through the cooling water path when the engine is operating. And the 1st calculation means which calculates the heating required flow rate which is the cooling water flow rate required for the heating at the time of a heating request, and the oil warmer required flow rate which is the cooling water flow rate required to heat the hydraulic oil to the warm-up completion temperature The heater core using at least the larger required flow rate of the heating required flow rate and the oil warmer required flow rate respectively calculated by the second calculation means for calculating the flow rate, and the first calculation means and the second calculation means. And a third calculating means for calculating a required cooling water flow rate required for heating the heating device, and a control for controlling the driving of the water pump based on the required cooling water flow rate calculated by the third calculating means. And means.

  In a vehicle including a heater core for heating a vehicle interior and a heating device that heats hydraulic oil for in-vehicle devices, the hydraulic oil is warmed early when the hydraulic oil is at a low temperature while responding to a heating request from the user. There is a need. For example, in a configuration including a transmission as an in-vehicle device, when the hydraulic oil (lubricating oil) supplied to the transmission is in a low temperature state, it is heated early, thereby reducing the motion loss of the internal combustion engine, and thus Improved fuel economy. In this case, in the configuration in which the heater core and the heating device each use the cooling water of the internal combustion engine as the heat source, it is possible to adjust the flow state of the cooling water while taking into account both the convenience on the heater core side and the convenience on the heating device side. desirable.

  In this regard, according to the configuration of the present invention, the required heating flow rate at the time of the heating request (cooling water flow rate required for heating) and the oil warmer required flow rate (the cooling water flow rate required to heat the hydraulic oil to the warm-up completion temperature) Further, the required cooling water flow rate required for heating the heater core and the heating device is calculated using at least the larger required flow rate among the required flow rates. Then, the driving of the water pump is controlled based on the required coolant flow rate. Thereby, both a heating request | requirement and the heating request | requirement of hydraulic oil (oil warmer request | requirement) can be grasped | ascertained, and cooling water can be distribute | circulated with a suitable request | required cooling water flow rate. For example, even in a situation where only a heating oil heating request is generated, an appropriate amount of cooling water according to the request can be circulated. In addition, a water pump that is driven separately from the internal combustion engine is used as the water pump, and in addition, since the control that takes into account both requirements as described above is performed, even when the internal combustion engine is stopped, An appropriate amount of cooling water according to each request can be distributed.

  As described above, in a vehicle in which both a heating request and a hydraulic oil heating request can occur, an appropriate amount of cooling water can be circulated through the cooling water path reflecting both the requests.

The block diagram which shows the outline of the vehicle system in embodiment of invention. The figure which shows the structure of an air conditioner. The functional block diagram which shows the calculation logic of water pump drive amount. The block diagram which shows the structure of the calculation part M1. The block diagram which shows the structure of the calculation part M2. The block diagram which shows the structure of the calculation part M3. The block diagram which shows the structure of the calculation part M4. The block diagram which shows the structure of the calculation part M5. The figure for setting a drive duty. The flowchart which shows the procedure of the calculation process which calculates water pump drive amount. The time chart which shows the behavior at the time of the cold start of an engine. The figure which shows another structure of a cooling system.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. The present embodiment is applied to a vehicle equipped with a water-cooled internal combustion engine and a transmission. First, the configuration of the vehicle system will be described with reference to FIG.

  In FIG. 1, an engine 10 (internal combustion engine) is a combustion engine that generates a desired torque by burning fuel supplied by a fuel injection valve (not shown). A transmission 11 is provided on an output shaft of the engine 10. It is connected. The transmission 11 is a known transmission such as an automatic transmission or a CVT (non-transmission). When the engine 10 rotates, the rotation is transmitted via the transmission 11 and the wheels rotate.

  Next, the configuration of the cooling system of the engine 10 will be described. In the engine 10, an engine internal water passage 12 is formed in a cylinder block and a cylinder head, and the engine 10 is cooled by circulating and supplying cooling water to the engine internal water passage 12. A circulating water passage 15 (cooling water passage) composed of a cooling water pipe or the like is connected to the engine internal water passage 12. The circulating water passage 15 is provided with a mechanical water pump 13 that is driven to rotate by the engine 10 on the outlet side thereof, and the water pump 13 is driven during operation of the engine 10 to cool the circulating water passage 15. Water circulates.

  The circulating water channel 15 branches in two directions below the water pump 13, one of which is a radiator side water channel 16 and the other is a heater core side water channel 17. The radiator-side water channel 16 is provided with a radiator 18 as an atmospheric heat radiating portion, and a thermostat 19 is provided downstream thereof. The thermostat 19 is a flow path switching means that changes the flow path of the cooling water by operating according to the cooling water temperature. Therefore, when the cooling water is at a low temperature (below the thermostat operating temperature), the inflow of the cooling water into the radiator side water channel 16 is blocked by the thermostat 19, and the cooling water is not radiated by the radiator 18, and is circulated through the circulation water channel 15. Circulate. For example, cooling of the cooling water (radiation) at the radiator 18 is suppressed before the warm-up of the engine 10 is completed (during warm-up operation). Further, when the cooling water reaches a high temperature (above the thermostat operating temperature), the cooling water is allowed to flow into the radiator side water passage 16 by the thermostat 19, and the cooling water circulates in the circulation water passage 15 while being radiated by the radiator 18. Thereby, the cooling water is maintained at an appropriate temperature (for example, about 80 ° C.) under the engine operating condition.

  The heater core side water channel 17 is provided with a heater core 21 that is a heat exchanger for heating the passenger compartment. Air conditioned air (inside air or outside air) is sent from the blower fan 22 to the heater core 21, and the air conditioned air passes through the heater core 21, whereby the air conditioned air is heated by the heat received from the heater core 21, and the warm air Is supplied to the passenger compartment.

  The heater core 21 and the blower fan 22 constitute an air conditioner 23 (in particular, a heating device in the present embodiment) that air-conditions the passenger compartment. The configuration of the air conditioner 23 will be briefly described with reference to FIG. In the air conditioner 23, a blower fan 22, an evaporator 25, an air mix damper 26, a heater core 21 and the like are accommodated in a case 24. The blower fan 22 is an electric blower capable of adjusting the air volume. When the blower fan 22 is driven, air flows through the flow passage in the case, and the air passes through the evaporator 25 and the heater core 21. Thereby, air is cooled and cooling air is produced | generated, or air is heated and heating air is produced | generated. Air-conditioned air, such as cooling air and heating air, is blown out to the blow-out destination determined by the blow-out switching damper. The evaporator 25 constitutes a refrigeration cycle together with a compressor, a condenser and the like (not shown).

  The air mix damper 26 is air-conditioning air switching means for distributing the ventilation air to either the heating passage on the heater core side or the cooling air passage on the opposite side on the downstream side of the evaporator 25. By adjusting the degree (damper opening), the air volume ratio between the heating passage and the cold air passage can be adjusted.

  Returning to the description of FIG. 1, an electric water pump 31 is provided downstream of the heater core 21 in the heater core side water channel 17. The water pump 31 is driven independently of the engine 10 and is driven by power supply from the in-vehicle battery. Thereby, it is possible to circulate cooling water through the heater core side water channel 17 regardless of the operating state of the engine 10. The water pump 31 is driven by a control signal such as a duty ratio signal, and the flow rate of the cooling water can be adjusted by changing the driving state.

  Further, in the heater core side water channel 17, oil as a hydraulic oil heating device (heat converter for heating hydraulic oil) for heating the hydraulic oil (lubricating oil) supplied to the transmission 11 is provided downstream of the water pump 31. A warmer 32 is provided. The transmission 11 and the oil warmer 32 are connected via an oil passage 33, and the hydraulic oil warmed by the oil warmer 32 is supplied to the transmission 11 through the oil passage 33.

  In the present embodiment, the heater core-side water channel 17 is provided with a heater core 21, a water pump 31, and an oil warmer 32 in series in this order. In the following description, for convenience, the mechanical water pump 13 provided on the engine outlet side is referred to as a mechanical water pump 13, and the electric water pump 31 provided on the heater core outlet side is referred to as an electric water pump 31. And

  The ECU 40 is an electronic control device that performs various controls of the vehicle. That is, as is well known, the ECU 40 is mainly composed of a microcomputer including a CPU, ROM, RAM, and the like, and executes various control programs stored in the ROM, thereby executing various controls in this system. In this system, as a detection means for detecting various information, a rotation speed sensor that detects the engine rotation speed, a water temperature sensor that detects the temperature of the cooling water (water temperature), and the temperature (oil temperature) of the hydraulic fluid for the transmission are detected. An oil temperature sensor that detects the outside air temperature, an evaporator temperature sensor that detects the air temperature (evaporator temperature) after passing the evaporator in the air conditioner 23, and the detection signals of these various sensors are appropriately sent to the ECU 40. Entered. Of the sensors described above, the temperature sensor is provided at the engine outlet portion in the circulation channel 15 and the engine outlet water temperature is calculated from the detection signal.

  Further, the vehicle of the present embodiment has an idle stop function for automatically stopping the engine in accordance with the vehicle running state when the ignition switch is on. When a predetermined automatic stop condition is satisfied, the vehicle-mounted ECU ( The engine is automatically stopped by the idle stop ECU). When a predetermined restart condition is satisfied after the engine is automatically stopped, the starter device (not shown) is driven by the in-vehicle ECU and the engine is restarted. Examples of the automatic stop condition include that the accelerator is off, that the brake is on, and that the vehicle speed is equal to or lower than a predetermined value. In addition, the restart condition includes, for example, that the accelerator is on, the brake is off, and the like.

  By the way, in the structure provided with the heater core 21 for heating the vehicle interior and the oil warmer 32 for heating the hydraulic oil as described above, the hydraulic oil is used when the hydraulic oil is at a low temperature while responding to the heating request from the user. It is necessary to warm up early. Therefore, in the present embodiment, both the heating request and the hydraulic oil heating request (oil warmer request) are grasped, and the flow rate of the cooling water is controlled by driving the electric water pump 31 in order to satisfy each of these requests. To do. In addition, since the cooling water is circulated through the circulating water passage 15 by driving the mechanical water pump 13 when the engine 10 is operated, the electric water is taken into account by adding the circulation amount of the cooling water by driving the mechanical water pump 13. The flow rate of the cooling water is controlled by driving the pump 31.

  First of all, in brief, when a heating request is made, the heating request flow rate that is the cooling water flow rate required for heating and the oil warmer request flow rate that is the cooling water flow rate required to heat the hydraulic oil to the warm-up completion temperature are calculated. Then, based on these required flow rates, the required coolant flow rate required for heating the heater core 21 and the oil warmer 32 is calculated. Further, the circulation amount of the cooling water (machine W / P flow rate) that circulates through the cooling water path with the driving of the mechanical water pump 13 during the operation of the engine 10 is calculated. The electric water pump 31 is driven such that the driving amount of the electric water pump 31 increases as the required cooling water flow rate increases, and the driving amount of the electric water pump 31 increases as the cooling water circulation amount decreases. Control.

  FIG. 3 is a functional block diagram showing logic for calculating the driving amount of the electric water pump 31, which is realized by the ECU 40.

In FIG. 3, the ECU 40
(1) A calculation unit M1 that calculates a heating required heat flow that is a heat flow (heat amount per unit time) necessary for heating based on the target outlet temperature TAO, the evaporator temperature, and the water temperature of the air conditioner 23;
(2) A calculation unit M2 that calculates an oil warmer required heat flow that is a heat flow (heat amount per unit time) necessary for heating the hydraulic oil based on the outside air temperature and the oil temperature;
(3) A calculation unit M3 that calculates a machine W / P flow rate that flows through the mechanical water pump 13 during engine operation based on the engine rotation speed;
(4) A calculation unit M4 that calculates a required cooling water flow rate based on the heating required heat flow and the blown air amount calculated by the calculation unit M1, and the oil warmer required heat flow calculated by the calculation unit M2.
(5) A calculation unit M5 that calculates the water pump drive amount based on the machine W / P flow rate calculated by the calculation unit M3 and the required coolant flow rate calculated by the calculation unit M4 is provided.

  Hereinafter, each part will be described in detail. As shown in FIG. 4, the calculation unit M1 includes an air volume calculation unit M11, an actual blowing temperature calculation unit M12, an air mix ratio calculation unit M13, and a heat flow calculation unit M14. Among these, the air volume calculation unit M11 calculates the blown air volume based on the target blow temperature TAO. For example, in the region where TAO = 5 to 60 ° C., the blown air volume is fixed at 100 kg / h, and in the lower and higher regions, a predetermined upper limit value is set and the blown air volume is variably set based on TAO. .

In addition, although the calculation method of the target blowing temperature TAO is well-known and various methods are proposed, it is good to calculate, for example by following Formula.
Tao = Ktset / Tset-Kr / Tr-Kam / Tam + C
Tset is the set temperature in the passenger compartment, Tr is the room temperature, and Tam is the outside air temperature. Further, Ktset, Kr, and Kam are gains for each of the above temperatures, and C is a constant.

  The actual blowing temperature calculation unit M12 calculates the actual blowing temperature based on the target blowing temperature TAO. At this time, the evaporator temperature + α (constant) is set as the lower limit value, and the water temperature −β (constant) is set as the upper limit value. When TAO is high, the actual blowout temperature is calculated to be higher than when it is low. To do. The air mix ratio calculation unit M13 calculates the air mix ratio based on the target blowing temperature TAO. At this time, when the TAO is high, the air mix ratio is larger than when the TAO is low, that is, the air mix ratio is calculated so that the heater core side passage amount increases in the air conditioner 23.

And the heat flow calculation part M14 calculates a heating request | requirement heat flow by following Formula.
Heating requirement heat flow = Cp x blowing air volume x air mix ratio x (actual blowing temperature-evaporator temperature)
Cp is air specific heat.

  Further, as shown in FIG. 5, the calculation unit M2 includes a heat flow base value calculation unit M21, a correction value calculation unit M22, and a correction unit M23. Among these, the heat flow base value calculation unit M21 calculates a heat flow base value based on the oil temperature (the temperature of the hydraulic oil), and the correction value calculation unit M22 calculates a correction value based on the outside air temperature. The correction unit M23 calculates the oil warmer required heat flow by multiplying the heat flow base value and the correction value. In the calculation unit M2, for example, when the outside air temperature is equal to or lower than a predetermined temperature (10 ° C.), the oil warmer required heat flow is set at a maximum value of 3 kW.

  As shown in FIG. 6, the calculation unit M3 calculates the machine W / P flow rate so as to increase as the engine speed increases.

  Further, as shown in FIG. 7, the calculation unit M4 includes a heating request flow rate calculation unit M41, a γ calculation unit M42, a guard flow rate calculation unit M43, and an oil warmer request flow rate calculation unit M44. Of these, the heating request flow rate calculation unit M41 calculates the heating request flow rate so that the heating request flow rate increases as the heating request heat flow increases. In particular, γ is a heat flow reference value for limiting the required heating flow rate to the maximum value (12 L / min), and γ is calculated based on the difference between the water temperature and the evaporator temperature in the γ calculating unit M42. It has come to be. In the γ calculation unit M42, for example, when the water temperature increases, γ shifts to a large value. Thereby, when water temperature becomes high, even if heating request | requirement heat flow is the same, heating request | requirement flow volume will become small. This is because the higher the water temperature (engine outlet water temperature), the more heat energy available in the heater core 21 is considered.

  The guard flow rate calculation unit M43 calculates the guard flow rate so as to increase as the amount of blown air increases. The oil warmer required flow rate calculation unit M44 calculates the oil warmer required flow rate so as to increase as the oil warmer required heat flow increases.

  The heating request flow rate calculated by the heating request flow rate calculation unit M41 is guarded as necessary with the guard flow rate calculated by the guard flow rate calculation unit M43, and the heating request flow rate and the oil warmer request flow rate calculation unit M44 are calculated. The larger one of the required oil warmer flow rates is calculated as the required cooling water flow rate.

  Further, as shown in FIG. 8, the calculation unit M5 uses a three-dimensional map having the machine W / P flow rate and the required coolant flow rate as parameters, and calculates the drive duty as the water pump drive amount. At this time, the drive duty is calculated to a larger value as the machine W / P flow rate is smaller, and on the other hand, the drive duty is calculated to be larger as the required coolant flow rate is larger.

  The relationship shown in FIG. 8 can be rewritten as shown in FIG. That is, in FIG. 9, a relationship is defined in which “requested coolant flow rate−machine W / P flow rate” is used as a parameter and the drive duty increases as it increases.

  FIG. 10 is a flowchart showing a procedure of calculation processing for calculating the water pump drive amount, and this processing is performed by the ECU 40 at a predetermined time period.

  In FIG. 10, in step S <b> 11, it is determined whether or not a heating request is currently made (whether heating is being performed). This request determination is performed, for example, according to the operation state of the air conditioning setting switch in the passenger compartment. If the heating request has occurred, the process proceeds to step S12, and the heating request heat flow and the heating request flow rate Q1 are calculated. These calculation methods are as described in the calculation unit M1 in FIG. 4 and the calculation units M41 to M43 in FIG. If no heating request is generated, the process proceeds to step S13, where the heating request flow rate Q1 is set to zero.

  Thereafter, in step S14, it is determined whether or not there is currently a request for heating the hydraulic oil. This request determination is performed according to, for example, the oil temperature. If the heating request has occurred, the process proceeds to step S15, and the oil warmer required heat flow and the oil warmer required flow rate Q2 are calculated. These calculation methods are as described in the calculation unit M2 in FIG. 5 and the calculation unit M44 in FIG. If no heating request is generated, the process proceeds to step S16 and the oil warmer required flow rate Q2 is set to zero.

  Thereafter, in step S17, the heating request flow rate Q1 and the oil warmer request flow rate Q2 are compared to determine whether or not Q1 ≧ Q2. And if it is Q1> = Q2, it will progress to Step S18 and will make heating demand flow volume Q1 into demand cooling water flow volume. If Q1 <Q2, the process proceeds to step S19, and the oil warmer required flow rate Q2 is set as the required cooling water flow rate.

  Thereafter, in step S20, it is determined whether or not the engine 10 is currently operating. That is, it is determined whether the mechanical water pump 13 is driven as the engine 10 is operated. If the engine is operating, the process proceeds to step S21 to calculate the machine W / P flow rate. This calculation method is as described in the calculation unit M3 in FIG. If the engine is not operating, the process proceeds to step S22 and the machine W / P flow rate is set to zero.

  Finally, in step S23, the water pump drive amount is calculated based on the required coolant flow rate and the machine W / P flow rate. This calculation method is as described in the calculation unit M5 in FIG.

  FIG. 11 is a time chart showing the behavior of each parameter when the engine 10 is cold started. In this example, both the water temperature and the oil temperature are −10 ° C. when the engine is started. Moreover, the behavior in the state with a heating request | requirement is shown.

  In FIG. 11, before the timing t1, the water temperature and the oil temperature gradually increase with the operation of the engine 10, and the water temperature (engine outlet water temperature) reaches the heating start temperature Ta (for example, 45 ° C.) at the timing t1. Thereby, execution of vehicle interior heating is permitted, the blower fan 22 is turned on, and heating is started. Prior to timing t1, heating is not performed regardless of whether there is a heating request, and both the heating heat flow and the heating required flow rate are zero. Further, after timing t1, execution of automatic stop of the engine 10 by idle stop control is permitted.

  Prior to timing t1, the oil warmer required flow rate is calculated according to the oil temperature, and this is the required cooling water flow rate. At this time, when the engine rotation speed decreases, the machine W / P flow rate decreases accordingly. However, since the required coolant flow rate is set according to the oil warmer required flow rate, the flow rate ((d The oil warmer flow rate) is maintained at a desired amount (A in the figure). That is, when the oil warmer flow rate is insufficient from the viewpoint of early warm-up of the hydraulic oil, the shortage is compensated by driving the electric water pump 31.

  After timing t1, the required heating flow rate is calculated based on the target blowing temperature, the water temperature, and the like, and the required cooling water flow rate is set according to the magnitude comparison between the required heating flow rate and the oil warmer required flow rate. Immediately after the timing t1, the control for gradually increasing the blowing temperature of the air conditioner 23 according to the water temperature is performed, and the required heating flow rate is gradually increased. After timing t1, the oil warmer flow rate is adjusted by the larger one of the heating required flow rate and the oil warmer required flow rate. Further, the electric water pump 31 is driven based on the machine W / P flow rate and the required coolant flow rate. For example, in the comparison of the machine W / P flow rate and the required coolant flow rate, if the machine W / P flow rate is less than the required coolant flow rate, the motor is driven with a drive duty corresponding to (requested coolant flow rate−machine W / P flow rate). When the water pump 31 is driven (B in the figure) and the machine W / P flow rate> the required coolant flow rate, the drive duty is set to 0 (C in the drawing).

  Thereafter, at timings t2 to t3, the engine 10 is automatically stopped by the idle stop function. At this time, the driving of the mechanical water pump 13 is stopped, but the circulation of the cooling water is continued by the driving of the electric water pump 31, and the oil warmer flow rate is maintained at a desired amount. The same applies to the timings t4 to t5 and t6 to t7.

  Here, as the water temperature and the oil temperature increase, the heating request flow rate and the oil warmer request flow rate respectively start to decrease after D in the figure and gradually approach zero. At time t8, the oil temperature reaches a warm-up completion temperature Tb (for example, 40 ° C.), and heating of the hydraulic oil (warming up of the transmission 11) is completed. In this case, according to the comparison between the required heating flow rate and the required oil warmer flow rate as described above, if the required heating flow rate <the required oil warmer flow rate, the required oil warmer flow rate should be ensured by using the required oil warmer flow rate. In addition, since the oil warmer flow rate is secured by driving the electric water pump 31 even while the engine is stopped, the temperature of the hydraulic oil is increased. Therefore, the mechanical loss of the transmission 11 can be reduced when the engine 10 is cold-started, and thus fuel consumption can be reduced.

  In FIG. 11, when the water temperature is low (for example, before t1), since the difference between the water temperature and the oil temperature is small, the amount of heat used in the oil warmer 32 is small, in other words, there is little influence on the warm-up of the engine 10. Further, when the engine 10 is automatically stopped in a state where there is a sufficient amount of heat during heating, the temperature of the hydraulic oil is promoted by continuing to flow the cooling water through the oil warmer 32. As a result, it is possible to optimize the heat flow required for heating and hydraulic fluid heating so that (total fuel consumption deterioration due to engine warm-up delay) <(fuel economy improvement due to hydraulic oil warm-up). Can contribute.

  According to the embodiment described in detail above, the following excellent effects can be obtained.

  Calculate the required heating flow rate (cooling water flow rate required for heating) and the oil warmer required flow rate (cooling water flow rate required for heating the hydraulic oil to the warm-up completion temperature), and the larger of the required flow rates. The required coolant flow rate required for heating the heater core 21 and the oil warmer 32 is calculated using the flow rate (calculation unit M4 in FIG. 7). The driving of the electric water pump 31 is controlled based on the required cooling water flow rate and the machine W / P flow rate that is the cooling water circulation amount by the mechanical water pump 13. Thereby, both a heating request | requirement and the heating request | requirement (oil warmer request | requirement) of hydraulic fluid are grasped | ascertained, and an appropriate amount of cooling water can be distribute | circulated. For example, even in a situation where only a heating oil heating request is generated, an appropriate amount of cooling water according to the request can be circulated. Further, by using the electric water pump 31, even when the engine 10 is stopped, it is possible to distribute an appropriate amount of cooling water according to each request. Furthermore, by taking into account the cooling water circulation amount by the mechanical water pump 13, the electric water pump 31 can be driven without excess or deficiency in heating or heating of the hydraulic oil.

  As described above, in a vehicle in which both a heating request and a hydraulic oil heating request can occur, an appropriate amount of cooling water can be circulated through the cooling water path reflecting both the requests. In this case, when the hydraulic oil (lubricating oil) supplied to the transmission 11 is in a low temperature state, it can be warmed up early, and the motion loss of the engine 10 can be reduced to improve fuel efficiency.

  Regarding the driving of the electric water pump 31, the driving amount of the electric water pump 31 increases as the required cooling water flow rate increases, and the driving of the electric water pump 31 decreases as the machine W / P flow rate (cooling water circulation amount) decreases. The drive of the water pump 31 was controlled by increasing the amount.

  In short, when the engine 10 is in operation, the cooling water circulates in the circulation channel 15 regardless of the heating request or the hydraulic oil heating request. In this case, in order to properly control the drive amount of the electric water pump 31 under such a cooling water circulation situation, in consideration of the machine W / P flow rate in each case, according to the heating request or the hydraulic oil heating request. It is desirable to drive the electric water pump 31. In this regard, according to the above-described configuration, it is possible to suppress the drive amount of the electric water pump 31 from becoming excessive during the operation of the engine 10.

  When the engine 10 is operated, the machine W / P flow rate is calculated based on the engine rotation speed. The machine W / P flow rate during engine operation depends on the engine rotation speed, and the machine W / P flow rate increases as the engine rotation speed increases. When the engine 10 is stopped, the machine W / P flow rate becomes zero. In this case, the machine W / P flow rate is calculated based on the engine rotation speed, and the drive of the electric water pump 31 is controlled according to the machine W / P flow rate, so that the engine 10 is in a low rotation state or a high rotation state. The electric water pump 31 can be driven appropriately depending on whether it is in a stopped state or the like.

  In the calculation unit M4 of FIG. 7, the heat quantity reference value γ is calculated based on the difference between the engine outlet water temperature and the evaporator temperature, and the required heating flow rate is limited to the maximum value by the γ. This is based on the engine outlet water temperature and calculates the required heating flow rate in consideration of the amount of cooling water thermal energy available in the heater core 21. That is, when the engine 10 is cold-started, the water temperature (engine outlet water temperature) gradually increases from a low temperature, and in the temperature increase process, the amount of heat energy that can be extracted by the heater core 21 depends on the water temperature at each time. Is different. In this respect, the electric water pump 31 can be made more appropriate in the situation where the heating request is generated by calculating the heating required flow rate in consideration of the amount of heat energy available in the heater core 21 based on the engine outlet water temperature. It can be driven.

  As a configuration of the cooling system, an oil warmer 32 is disposed on the downstream side of the heater core 21. Usually, the outlet temperature of the heater core 21 is 40 ° C. or higher, which is higher than the temperature required for heating the hydraulic oil in the oil warmer 32 (about 30 to 40 ° C.). Therefore, it becomes possible to heat the hydraulic oil while maintaining heating. In addition, when priority is given to heating the hydraulic oil, the heating function is stopped (for example, the air volume is set to 0 or the air mix ratio is set to 0%), so that only the oil warmer 32 is added without adding a new device. Can tell the amount of heat.

(Other embodiments)
You may change the said embodiment as follows, for example.

  In the above embodiment, the larger required flow rate of the required heating flow rate (cooling water flow rate required for heating) and the oil warmer required flow rate (cooling water flow rate required to heat the hydraulic oil to the warm-up completion temperature) Although it was set as the structure which calculates a request | required cooling water flow rate using, you may change this. For example, both the heating required flow rate and the oil warmer required flow rate are used. Specifically, the larger required flow rate of the heating required flow rate and the oil warmer required flow rate is corrected to increase according to the smaller required flow rate, and the required cooling water flow rate is calculated from the corrected value. Good. In this case, the increase correction is increased as the smaller required flow rate is larger. Alternatively, the required heating flow rate and the oil warmer required flow rate may be added, and the required cooling water flow rate may be calculated from the added value.

  Even if the engine outlet water temperature is the same, the amount of heat energy that can be used in the oil warmer 32 varies depending on how much heat energy is used in the heater core 21. That is, the amount of heat that can be used by the oil warmer 32 to heat the hydraulic oil changes according to the water temperature on the outlet side of the heater core 21. Therefore, in FIG. 1, a temperature sensor is provided on the outlet side of the heater core 21 so that the heater core outlet water temperature can be detected. Then, in the oil warmer required flow rate calculation unit M44 in FIG. 7, the oil warmer required flow rate is calculated based on the oil warmer required heat flow and the heater core outlet water temperature. In this case, the oil warmer required flow rate may be calculated as a larger value as the heater core outlet water temperature is lower. As a result, the electric water pump 31 can be driven more appropriately in a situation where a heating oil heating request is generated.

  -You may change the structure of a cooling system as follows. In FIG. 12, a part thereof is changed based on the configuration of FIG.

  In FIG. 12A, a bypass water channel 51 that bypasses the oil warmer 32 is provided downstream of the electric water pump 31 in the circulation water channel 15 (heater core side water channel 17), and the heater core side water channel 17 and the bypass water channel 51 are provided. A water channel switching valve 52 is provided at the branch position. Then, the ECU 40 determines which of the heating request and the hydraulic oil heating request has priority, and switches the water channel switching valve 52 to the oil warmer bypass side when giving priority to the heating request (that is, to the oil warmer 32). Do not allow cooling water to flow). According to this configuration, when the amount of heat necessary for heating is insufficient, the oil warmer 32 can be bypassed and the cooling water can be circulated, and the heating performance can be ensured.

  In FIG. 12B, in the circulating water channel 15 (heater core side water channel 17), the heater core 21 and the oil warmer 32 are connected in parallel, and the electric water pump 31 is arranged before branching on the upstream side. Alternatively, the electric water pump 31 may be disposed after joining the heater core 21 and the oil warmer 32 on the downstream side. In such a configuration, the temperature of the cooling water flowing into the oil warmer 32 is higher than that in the configuration in which the oil warmer 32 is disposed on the downstream side of the heater core 21. Therefore, the effect of promoting heating of the hydraulic oil can be enhanced.

  In addition, the following configurations can be adopted. A configuration provided with heating means other than the heater core 21 may be used as the heating means of the air conditioner 23. For example, a heat pump or a PTC heater is used. In this configuration, vehicle interior heating is performed by heating means other than the heater core 21 in a state where the water temperature is low or the oil temperature is low. Thereby, the heating heat amount by the heater core 21 can be reduced, and the heat amount of the oil warmer 32 can be increased to promote the heating of the hydraulic oil while maintaining the heating performance.

  In addition, a cooling water heating means such as an exhaust heat recovery device or an electric heater is added in the circulation water channel 15 (heater core side water channel 17). The exhaust heat recovery device is a device that recovers heat of exhaust gas discharged from, for example, an engine and heats cooling water. According to this configuration, since the amount of heat that can be used for heating or heating of the hydraulic oil increases, heating of the heating or hydraulic oil can be promoted. In particular, the exhaust heat recovery device has a great practical effect because no additional fuel is required. Further, even in the case of heating by consuming energy such as an electric heater, a practical effect can be obtained if the loss reduction effect due to warming up of the transmission 11 is greater.

  In the above embodiment, the mechanical water pump 13 that is driven as the engine 10 is operated and the electric water pump 31 that is driven independently of the operation of the engine 10 are used as the water pump. However, a configuration using only an electric water pump is also possible. In practice, in the configuration of FIG. 1, the electric water pump 31 is eliminated, and an electric water pump is provided instead of the mechanical water pump 13. That is, the mechanical water pump is electrified, and the engine water pump and the water pump for heating and hydraulic oil heating are combined. Thereby, a structure can be simplified and cost reduction can be aimed at.

  In this case, when the engine 10 is operated, the ECU 40 drives the water pump according to the engine operating state such as the engine rotation speed and the engine load (intake pressure, intake air amount, etc.). In the functional block diagram shown in FIG. 3, the calculation unit M3 calculates the coolant circulation amount based on the engine speed and the engine load. This is also the required flow rate for engine cooling. Then, the calculation unit M5 considers the heating request and the hydraulic oil heating request from the “cooling water circulation amount” calculated by the calculation unit M3 and the “required cooling water flow rate” calculated by the calculation unit M4. The driving amount is calculated. The calculation unit M5 increases the amount of driving of the water pump in order to compensate for the amount of cooling water that circulates according to the operating state of the engine 10 and the flow rate that is considered to be insufficient due to the heating request or the heating request for hydraulic oil. Will be calculated. At this time, the driving of the water pump is controlled so that the driving amount of the water pump increases as the required cooling water flow rate increases, and the driving amount of the water pump increases as the cooling water circulation amount decreases.

  In the above embodiment, a transmission is assumed as the in-vehicle device, and the hydraulic oil for the transmission is heated by the oil warmer 32. In addition, a differential gear (differential gear) is assumed as the in-vehicle device. In addition, the hydraulic oil for the differential gear may be heated by the oil warmer 32.

  The cooling system of the present invention can be applied to a hybrid vehicle having a traveling motor and a traveling engine. In this case, since there are many opportunities to stop the engine operation while the vehicle is running (when the vehicle power switch is on), the electric water pump is used to meet the heating request and the hydraulic oil heating request as described above. It is very meaningful to respond.

  DESCRIPTION OF SYMBOLS 10 ... Engine (internal combustion engine), 15 ... Circulating water path (cooling water path), 21 ... Heater core, 31 ... Electric water pump, 32 ... Oil warmer (heating device), 40 ... ECU (1st-4th calculation means, control) means).

Claims (5)

A water pump (31) provided in a cooling water path (15) connected to the internal combustion engine (10) and driven separately from the internal combustion engine to distribute the cooling water to the cooling water path;
A heater core (21) for vehicle interior heating provided in the cooling water path;
Provided in series on the downstream side of Oite the heater core into the cooling water passage, a heating device for heating the working fluid for the vehicle device by the cooling water (32),
A cooling system for an on-vehicle internal combustion engine that circulates an amount of cooling water according to the operating state to the cooling water path when the internal combustion engine is operated,
First calculation means for calculating a heating request flow rate that is a cooling water flow rate required for heating at the time of a heating request;
Second calculating means for calculating an oil warmer required flow rate that is a cooling water flow rate required to heat the hydraulic oil to a warm-up completion temperature based on the water temperature on the outlet side of the heater core ;
For heating the heater core and the heating device using at least the larger required flow rate of the heating required flow rate and the oil warmer required flow rate calculated by the first calculation unit and the second calculation unit, respectively. Third calculating means for calculating a required cooling water flow rate,
Control means for controlling the driving of the water pump based on the required coolant flow rate calculated by the third calculation means;
An on-vehicle internal combustion engine cooling system comprising: A fourth calculating means for calculating a circulation amount of the cooling water circulating through the cooling water path in accordance with the operation of the internal combustion engine;
The control means increases the drive amount of the water pump as the required coolant flow rate calculated by the third calculation means increases, and decreases the coolant circulation amount calculated by the fourth calculation means. The cooling system for an on-vehicle internal combustion engine according to claim 1, wherein the driving amount of the water pump is controlled to increase the driving amount of the water pump. A mechanical water pump (13) that is driven by the rotation of the internal combustion engine and distributes the cooling water to the cooling water path is used as a first water pump, and when driven separately from the internal combustion engine. A cooling system for an internal combustion engine in which the water pump (31) is a second water pump,
The in-vehicle internal combustion engine according to claim 2, wherein the fourth calculating means calculates the flow rate of cooling water circulated by the first water pump during the operation of the internal combustion engine as the cooling water circulation amount, and calculates it based on the engine rotational speed. Engine cooling system.   The said 1st calculation means calculates the said heating request flow volume which considered the calorie | heat amount of the cooling water which can be utilized in the said heater core based on the temperature of the cooling water in the exit side of the said internal combustion engine. A cooling system for an in-vehicle internal combustion engine according to item. A water pump (31) provided in a cooling water path (15) connected to the internal combustion engine (10) and driven separately from the internal combustion engine to distribute the cooling water to the cooling water path;
A heater core (21) for vehicle interior heating provided in the cooling water path;
A heating device (32) which is provided in the cooling water path and heats hydraulic oil for on-vehicle equipment with the cooling water;
A cooling system for an on-vehicle internal combustion engine that circulates an amount of cooling water according to the operating state to the cooling water path when the internal combustion engine is operated,
First calculation means for calculating a heating request flow rate that is a cooling water flow rate required for heating at the time of a heating request;
Second calculating means for calculating an oil warmer required flow rate which is a cooling water flow rate required to heat the hydraulic oil to a warm-up completion temperature;
The larger required flow rate of the heating required flow rate and the oil warmer required flow rate calculated by the first calculation unit and the second calculation unit, respectively , is increased and corrected according to the smaller required flow rate, and the correction is performed. A third calculation means for calculating a required coolant flow rate required for heating the heater core and the heating device according to a later value ;
Control means for controlling the driving of the water pump based on the required coolant flow rate calculated by the third calculation means;
An on-vehicle internal combustion engine cooling system comprising:

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