JP6065785B2 - Cooling water temperature control system - Google Patents

Description

  The present invention relates to a cooling water temperature control system for controlling the temperature of engine cooling water.

  For example, Patent Document 1 discloses a heating control device for a hybrid vehicle that performs heating of a vehicle interior using engine coolant. In this heating control device, the temperature of the cooling water required for heating is set from environmental conditions such as outside air temperature, room temperature, and amount of solar radiation. Then, the actual temperature of the cooling water is detected by the water temperature sensor, and it is determined whether or not the detected temperature exceeds the set temperature. At this time, if it is determined that the detected temperature is lower than the set temperature, the engine ECU is requested to change the operating point of the engine. Then, the engine ECU changes the operating point of the engine so that the output power is the same and the efficiency is lowered. As a result, the amount of waste heat of the engine increases and the temperature of the cooling water rises.

JP-A-10-203145

  For example, when the vehicle starts to travel, the temperature of the engine and the cooling water is usually lowered to about the outside air temperature. When the temperature of the engine and the cooling water is low, not only the heating capacity is insufficient, but also the ratio of the energy used for combustion in the engine used to heat the engine becomes high, so that the thermal efficiency is deteriorated and the fuel consumption is deteriorated. Further, if the engine is not sufficiently warmed, the air-fuel mixture is not sufficiently vaporized, and the emission is likely to deteriorate.

  In the apparatus disclosed in Patent Document 1 described above, when the detected temperature of the cooling water is lower than the set temperature, the engine is operated at a low-efficiency operating point until the temperature of the cooling water reaches the set temperature. Therefore, the temperature of the engine and the cooling water can be raised to an appropriate temperature within a short time.

  However, for example, when the vehicle travels at a high load, the temperature of the engine and the cooling water may sufficiently increase due to heat generated by the engine when the vehicle travels without changing the operating point. In this case, as in Patent Document 1, if the engine operating point is changed to increase the amount of waste heat of the engine, fuel will be consumed wastefully.

  The present invention has been made in view of the above points, and provides a cooling water temperature control system capable of raising the temperature of engine cooling water to an appropriate temperature without wasting fuel. The purpose is to do.

In order to achieve the above object, a cooling water temperature control system according to a first aspect of the present invention provides:
Temperature detection means (22) for detecting the temperature of the cooling water of the engine;
Target value setting means (S100) for setting the target value of the cooling water temperature;
Target increase amount determining means (S140, S150) for determining a target increase amount of the coolant temperature per unit time when the coolant temperature detected by the temperature detection means is lower than the target value of the coolant temperature;
Control means ( S164, S172 , S190) for controlling the engine so that the amount of heat generated by the engine increases when the amount of increase in the coolant temperature detected by the temperature detection means per unit time is smaller than the target increase amount . ) and, with a,
The control means calculates a target temperature corresponding to the target increase amount based on the elapsed time after the target increase amount is determined, and the cooling water temperature detected by the temperature detection means does not reach the target temperature to increase the amount per unit time of the cooling water temperature, it characterized that you determined to be smaller than the target increase amount.

  As described above, in the present invention, the target increase amount of the cooling water temperature per unit time is determined, and the control to increase the heat generation amount of the engine depending on whether the actual increase amount of the cooling water temperature is smaller than the target increase amount It is determined whether or not is necessary. Therefore, according to the present invention, even when the temperature of the engine coolant is lower than the target value, when the actual amount of increase in the coolant temperature exceeds the target amount of increase, the heat generation amount of the engine is increased. Is not executed. In this case, it is because it can be considered that a necessary calorific value can be obtained by operating the engine for running the vehicle. As a result, it is possible to suppress consumption of excess fuel for heating the engine coolant.

Further, in the first invention described above, the control hand stage, based on the elapsed time from the target increase amount is determined, we calculate the target temperature in accordance with the target amount of increase. Thereby, in the control means, the amount of increase in the cooling water temperature per unit time is compared with the cooling water temperature detected by the temperature detecting means and the target temperature corresponding to the target increase amount, as in the prior art. However, it can be determined whether or not it is smaller than the target increase amount. Therefore, since most of the conventional control logic can be used as it is, it is possible to easily implement software and hardware for performing the control processing of the present invention. In addition, it is preferable that the target temperature according to the target increase amount calculated by the control means becomes larger as the elapsed time becomes longer. Thereby, it is possible to raise the cooling water temperature to the target value while suppressing wasteful consumption of fuel.

The cooling water temperature control system according to the second invention is:
Temperature detection means (22) for detecting the temperature of the cooling water of the engine;
Target value setting means (S100) for setting the target value of the cooling water temperature;
Target increase amount determination means for determining a target increase amount of the coolant temperature per unit time when the coolant temperature detected by the temperature detection means is lower than the coolant temperature target value set by the target value setting means (S140, S150),
Control means (S170, S190) for controlling the engine so that the amount of heat generated by the engine increases when the amount of increase in the coolant temperature detected by the temperature detection means per unit time is smaller than the target increase amount; ,
A load detecting means for calculating or estimating the load of the engine (S210), provided with,
Target increase amount determining means, when the engine load calculated or estimated by the load detecting means is high, as compared with the case lower than, you relatively small target increased amount of the cooling water temperature. Generally, when the engine load is high, the amount of heat generated by the engine is larger than when the engine load is lower. Therefore, when the engine load is high, there is a high possibility that the temperature of the cooling water will eventually rise to the target value without executing control for forcibly increasing the heat generation amount of the engine. Therefore, when the engine load is high, the target increase amount of the coolant temperature is relatively reduced. This makes it difficult to execute control for increasing the amount of heat generated by the engine, so that it is possible to more reliably suppress wasteful consumption of fuel.

Furthermore, the cooling water temperature control system according to the third invention is:
Temperature detection means (22) for detecting the temperature of the cooling water of the engine;
Target value setting means (S100) for setting the target value of the cooling water temperature;
Target increase amount determination means for determining a target increase amount of the coolant temperature per unit time when the coolant temperature detected by the temperature detection means is lower than the coolant temperature target value set by the target value setting means (S140, S150, S240-S270),
Control means (S170, S190) for controlling the engine so that the amount of heat generated by the engine increases when the amount of increase in the coolant temperature detected by the temperature detection means per unit time is smaller than the target increase amount; ,
Load detection means (S210) for calculating or estimating the engine load;
A calorific value calculating means (S220) for calculating the calorific value generated in the engine when the engine is operated so as to generate an engine output corresponding to the engine load calculated or estimated by the load detecting means;
A required heat quantity estimating means (S230) for estimating a required heat quantity for heating the cooling water,
Target increased amount determination hand stage, the amount of heat generated heat calculation means has calculated is greater than the required amount of heat is required heat estimating means estimated, compared to when smaller than the request heat, coolant temperature of you relatively small target increase amount. Judge whether the engine heat generation increase control is necessary with higher accuracy by considering the balance between the heat generation amount of the engine according to the engine load and the required heat amount for cooling water heating It is because it can do.

The cooling water temperature control system according to the fourth invention is:
Temperature detection means (22) for detecting the temperature of the cooling water of the engine;
Target value setting means (S100) for setting the target value of the cooling water temperature;
Target increase amount determination means for determining a target increase amount of the coolant temperature per unit time when the coolant temperature detected by the temperature detection means is lower than the coolant temperature target value set by the target value setting means (S140, S150, S410 to S430),
Control means (S170, S190) for controlling the engine so that the amount of heat generated by the engine increases when the amount of increase in the coolant temperature detected by the temperature detection means per unit time is smaller than the target increase amount; With
Target increased amount determination hand stage, from the cooling water temperature detected by the temperature detection means calculates the actual increase of the cooling water temperature per unit time, when the amount of increase in the actual is large, than compared to smaller, relatively reduced target increased amount of the cooling water temperature. When the actual amount of increase calculated from the cooling water temperature detected by the temperature detecting means is large, the temperature of the cooling water is likely to increase thereafter. Therefore, the target increase amount of the cooling water temperature is relatively reduced so that the control for increasing the heat generation amount of the engine is difficult to be executed. Thereby, it can suppress more reliably that fuel is consumed wastefully.

  Note that the reference numerals in the parentheses merely show an example of a correspondence relationship with a specific configuration in an embodiment described later in order to facilitate understanding of the present invention, and limit the scope of the present invention. It is not intended.

  Further, the features of the present invention described in the claims other than the features described above will be apparent from the description of embodiments and the accompanying drawings described later.

It is the block diagram which showed the structure of the whole cooling water temperature control system by 1st Embodiment. It is the flowchart which showed the control processing for raising a cooling water temperature, when a cooling water temperature is lower than suitable temperature performed in a cooling water temperature control system. It is a time chart which shows an example of the mode of change of the cooling water temperature at the time of performing the emitted-heat amount increase control of an engine, when the detected cooling water temperature is lower than target cooling water temperature. FIG. 3 is a time chart showing an example of a change in cooling water temperature when the control process of FIG. 2 is executed when the engine load is high and therefore the engine heat generation amount is large. FIG. FIG. 3 is a time chart showing an example of a change in cooling water temperature when the control process of FIG. 2 is executed when the engine load is low and therefore the amount of heat generated by the engine is small. It is a flowchart which shows the content of the control process in the modification of 1st Embodiment. It is a flowchart which shows the target raise amount correction process in 2nd Embodiment. It is a flowchart which shows the detail of an example of the engine load calculation process of step S210 of the flowchart of FIG. It is a flowchart which shows the target raise amount correction process in 3rd Embodiment.

(First embodiment)
Hereinafter, a cooling water temperature control system according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an overall configuration of a cooling water temperature control system according to the present embodiment. In the example shown in FIG. 1, the engine ECU (Electronic Control Unit) has a configuration that also functions as a cooling water temperature control ECU, which is one component of the cooling water temperature control system. . However, the cooling water temperature control ECU may be provided separately from the other ECUs, or an ECU (for example, an air conditioner ECU) other than the engine ECU has a function as a cooling water temperature control ECU. Also good.

  In FIG. 1, an engine 10 drives a wheel (not shown) by reciprocating a piston using thermal energy from combustion of fuel such as gasoline and converting the reciprocating motion into a rotational motion by a crank mechanism. Generates a driving force.

  The engine 10 is a water-cooled engine, and a so-called water jacket is formed in a cylinder head and a cylinder block around the combustion chamber. Cooling the cooling water through the water jacket by the pump 14 suppresses overheating due to combustion. The cooling water that has passed through the engine 10 circulates through the cooling water pipe 12. A radiator 16 is provided in the cooling water pipe 12 to reduce the temperature of the cooling water by exchanging heat with air. A radiator fan 18 is driven when the cooling air does not sufficiently hit the radiator 16 when the vehicle is traveling at a low speed or when the vehicle is stopped, and forcibly blows the cooling air to the radiator 16.

  Although not shown, a so-called thermostat valve is provided between the water jacket and the radiator 16. When the temperature of the cooling water after passing through the engine 10 is low (for example, 80 ° C. or lower), the thermostat valve switches the flow path so that the cooling water circulates without passing through the radiator 16.

  Here, if the engine 10 is overheated, the cylinder head may be deformed or the oil film of the lubricating oil may be cut off, possibly causing damage to the engine 10. On the contrary, if the engine 10 is cooled too much and the temperature of the engine 10 remains low, the thermal energy from combustion becomes higher in the ratio used to heat the engine 10, and the thermal efficiency becomes worse. Fuel consumption deteriorates. Further, if the engine is not sufficiently warmed, the air-fuel mixture is not sufficiently vaporized, leading to worse emission. Furthermore, when heating using cooling water, if the temperature of the engine 10 is low, there also arises a problem that sufficient heating capacity cannot be obtained.

  Therefore, the cooling water temperature control ECU 20 controls the cooling water of the engine 10 to an appropriate temperature by controlling the operation state of the pump 14 and the radiator fan 18 based on detection signals of various sensors. That is, the coolant temperature control ECU 20 includes a coolant temperature sensor 22 that detects the coolant temperature, an ambient temperature sensor 24 that detects the ambient temperature around the vehicle, a crank angle sensor 26 that detects the engine speed, and a throttle valve. Detection signals are taken in from a throttle opening sensor 28 that detects the opening, a vehicle speed sensor 30 that detects the traveling speed of the vehicle, and the like. Further, the coolant temperature control ECU 20 acquires information 32 related to the air conditioner set temperature from an air conditioner ECU (not shown). The cooling water temperature control ECU 20 determines a desirable engine temperature (cooling water temperature) based on these detection signals and information. Then, the cooling water temperature control ECU 20 controls the operating state of the pump 14 and the radiator fan 18 so that the temperature of the cooling water becomes the determined cooling water temperature, and the temperature of the engine 10 decreases at the time of starting or the like. If necessary, the engine ECU also controls the operating state of the engine 10 as necessary.

  Regarding the control of the operating state of the engine 10, conventionally, when the detected temperature of the cooling water is lower than the set temperature, the engine is operated at a low-efficiency operating point until the temperature of the cooling water reaches the set temperature. I was doing. Such change of the operating point is performed without considering the operating state of the engine. Therefore, even if the operating point is not changed, if the temperature of the cooling water sufficiently rises due to the heat generated by the engine when the vehicle travels, the fuel is consumed wastefully.

  Therefore, in the cooling water temperature control system according to the present embodiment, unless the operation state of the engine 10 is controlled, the operation state of the engine is controlled only when the cooling water temperature cannot be increased to an appropriate temperature. did. Hereinafter, the control process for increasing the cooling water temperature when the cooling water temperature is lower than the appropriate temperature, which is executed in the present embodiment, will be described with reference to the flowchart of FIG.

  First, in step S100, a target cooling water temperature is set. For example, when the vehicle includes an air conditioner, and the air conditioner includes a heater core and a pump, and has a heating device that performs heating using cooling water, and a cooling device that includes a refrigeration cycle including a compressor, an evaporator, and the like, The target cooling water temperature may be set according to whether or not the heater is in operation, that is, depending on whether the heater is on or off. As a specific example, when the heating device is turned on, the target cooling water temperature is set to 90 ° C. so that sufficient heating capacity can be secured. On the other hand, when the heating device is turned off, the target cooling water temperature is set to less than 70 ° C., and unnecessary heating of the engine 10 is suppressed. Alternatively, a predetermined constant temperature may be set as the target cooling water temperature.

  In the subsequent step S110, the current cooling water temperature is detected based on the detection signal from the water temperature sensor 22. In step S120, it is determined whether the current cooling water temperature is lower than the target cooling water temperature set in step S100. In this determination process, if it is determined that the current coolant temperature is lower than the target coolant temperature, the process proceeds to step S130. If it is determined that the coolant temperature is equal to or higher than the target coolant temperature, it is necessary to increase the coolant temperature. Therefore, the processing shown in the flowchart of FIG.

  In step S130, a time until the current cooling water temperature reaches the target cooling water temperature is set. For example, when the air conditioner (heating device) has an eco mode that prioritizes fuel saving and a comfort mode that prioritizes comfort as the operation mode, this arrival time is selected. It may be set according to whether or not. Specifically, the arrival time is set shorter when the comfort mode is selected than when the eco mode is selected. Thereby, when the comfortable mode is selected, it becomes possible to obtain the required heating capacity from the cooling water earlier. Alternatively, a predetermined fixed time may be set as the arrival time, or a time corresponding to the temperature difference between the current cooling water temperature and the target cooling water temperature may be set.

  In the subsequent step S140, a target increase amount of the cooling water temperature per unit time is calculated. For example, the target increase amount per unit time is calculated by dividing the temperature difference between the current cooling water temperature and the target cooling water temperature by the arrival time set in step S130. Alternatively, when the temperature difference between the current cooling water temperature and the target cooling water temperature is large, the target increase amount increases, and the target increase amount is calculated so that the target increase amount decreases as the temperature difference decreases. Also good. By calculating the target increase amount in this way, for example, when the heating device is operating, the target increase amount is greater than when the heating apparatus is not operating. Further, when the comfort mode is selected as the driving mode, the target increase amount is larger than when the eco mode is selected. Thereby, it can suppress that the shortage of heating capability generate | occur | produces.

  In the subsequent step S150, the target increase amount is further corrected so as to ensure the necessary heating capacity. For example, the first correction amount is calculated by multiplying the result of subtracting the outside air temperature from the air conditioner set temperature by a predetermined first coefficient. Then, the target increase amount is corrected by adding the first correction amount to the target increase amount. Alternatively, the second correction amount may be calculated by multiplying the result obtained by subtracting the room temperature from the air conditioner set temperature by a predetermined second coefficient, and the target increase amount may be corrected by adding the second correction amount to the target increase amount. good. Furthermore, the target increase amount may be corrected using the first correction amount and the second correction amount simultaneously. By correcting the target increase amount, the target increase amount is corrected so as to increase as the temperature difference from the set temperature increases. As a result, the required heating capacity can be secured early. However, the correction process of the target increase amount in step S150 may be omitted.

  In step S160, the actual amount of increase in the cooling water temperature per unit time is measured from the detection signal of the water temperature sensor. In step S170, it is determined whether or not the actual increase amount is equal to or greater than the target increase amount. If it is determined that the actual amount of increase is equal to or greater than the target amount of increase, the heat generated by the engine 10 as a result of controlling the engine 10 as usual without performing special control for increasing the amount of heat generated by the engine, It can be said that the cooling water temperature is likely to rise toward the target cooling water temperature. Therefore, in this case, the control of the engine 10 is kept at the normal control in step S180. On the other hand, when it is determined that the actual increase amount is less than the target increase amount, it is necessary to increase the heat generation amount of the engine 10. Therefore, the process proceeds to step S190, and the control of the engine 10 is switched to the heat generation amount increase control.

  As the heat generation amount increase control, for example, control for increasing the fuel injection amount, advancing the ignition timing, or operating the engine at a low-efficiency operating point as in the prior art may be performed. . Alternatively, if the vehicle is a hybrid vehicle that includes a motor as a travel drive source in addition to the engine 10 or has a so-called idle stop function that stops the engine when the vehicle is stopped, the amount of heat generation increases. The control may prohibit the stop of the engine 10 when the operation of the engine 10 is to be stopped.

  In step S200, it is determined whether or not the actual cooling water temperature has reached the target cooling water temperature. When it is determined that the target cooling water temperature has not yet been reached, the processing from step S100 described above is repeated. On the other hand, if it is determined that the target cooling water temperature has been reached, the processing shown in the flowchart of FIG. 2 is terminated.

  The effect obtained by the processing described above will be described using the time charts of FIGS. In the example shown in FIGS. 3 to 5, as the heat generation amount increase control, a process for prohibiting the engine from being stopped is adopted even when the required power for the engine becomes zero and the engine can be stopped.

  First, FIG. 3 shows an example of a change in the cooling water temperature when the heat generation amount increase control of the engine 10 is executed when the detected cooling water temperature is lower than the target cooling water temperature, as in the prior art. Is shown. In this case, it is possible that the amount of waste heat of the engine becomes too large and the cooling water temperature rises too much. As a result, as shown in FIG. 3, the cooling water is caused to flow through the radiator 16, and heat is released from the cooling water whose temperature has risen excessively. Such excessive heating and heat dissipation of the cooling water will waste fuel.

  On the other hand, FIG.4 and FIG.5 shows the mode of the cooling water temperature change at the time of performing the process mentioned above. Note that the time chart in FIG. 4 shows an example in which the engine load is high and the engine heat generation is large. Further, the time chart of FIG. 5 shows an example in which the engine load is low and therefore the heat generation amount of the engine is small. 4 and 5 show an example in which the target increase amount of the cooling water temperature is constant.

  By executing the processing described above, a target increase amount per unit time is determined. Therefore, as shown in the time charts of FIGS. 4 and 5, the target temperature line corresponding to the target increase amount gradually increases toward the target cooling water temperature as time elapses. When the actual cooling water temperature is lower than the target temperature line corresponding to the target increase amount, the heat generation amount increase control for prohibiting the engine stop is executed. On the other hand, when the cooling water temperature reaches the target temperature line corresponding to the target increase amount, the heat generation amount increase control ends, so that the engine can be stopped thereafter.

  In addition, when the cooling water temperature reaches the target temperature line corresponding to the target increase amount and the heat generation amount increase control is finished, the cooling water temperature is changed from the target temperature line (upper limit line) corresponding to the target increase amount. However, the heat generation amount increase control is not resumed unless it is lowered to a line (lower limit line) set lower by the hysteresis. Thereby, it is possible to prevent frequent repetition of the heat generation amount increase control being executed or stopped.

  As described above, in the cooling water temperature control system according to the present embodiment, the target increase amount of the cooling water temperature per unit time is determined, and whether the actual increase amount of the cooling water temperature is smaller than the target increase amount or not is determined. It is determined whether or not the control for increasing the heat generation amount is necessary. Therefore, according to the cooling water temperature control system of the present embodiment, even when the engine cooling water temperature is lower than the target cooling water temperature, when the actual cooling water temperature increase exceeds the target increase amount. The control for increasing the heat generation amount of the engine 10 is not executed. In this case, it is because it can be considered that a necessary calorific value is obtained by operating the engine 10 for running the vehicle. As a result, it is possible to suppress consumption of excess fuel in order to heat the cooling water of the engine 10.

(Modification of the first embodiment)
In the first embodiment described above, the actual amount of increase in cooling water temperature per unit time is measured in step S160 of the flowchart of FIG. 2, and in step S170, whether or not the actual amount of increase is equal to or greater than the target amount of increase. It was judged. However, instead of directly comparing the actual increase amount and the target increase amount, a target temperature corresponding to the target increase amount may be calculated, and the target temperature may be compared with the actual cooling water temperature.

  Specifically, as shown in the flowchart of FIG. 6, after executing the correction process of the target increase amount in step S150, first, as shown in step S162, the current coolant temperature is detected from the detection signal of the water temperature sensor 22. Is detected. In step S164, a target temperature corresponding to the target increase amount is calculated based on the elapsed time since the target increase amount was determined.

  In step S172, the detected current temperature is compared with the calculated target temperature to determine whether the current temperature is equal to or higher than the target temperature. If it is determined that the current temperature is equal to or higher than the target temperature, the process proceeds to step S180 in the flowchart of FIG. 2, and if it is determined that the temperature is lower than the target temperature, the process proceeds to step S190 in the flowchart of FIG. Proceed to processing.

  According to such a modification, the actual cooling water temperature per unit time is compared with the cooling water temperature detected by the water temperature sensor 22 and the target temperature corresponding to the target increase amount, as in the conventional case. It is possible to determine whether or not the increase amount is smaller than the target increase amount. Therefore, since most of the conventional control logic can be used as it is, it is possible to easily implement software and hardware.

  Further, the target temperature calculated in step S164 according to the target increase amount increases as the elapsed time becomes longer. Therefore, it is possible to reliably raise the cooling water temperature to the target cooling water temperature while suppressing wasteful consumption of fuel.

(Second Embodiment)
Next, a cooling water temperature control system according to a second embodiment of the present invention will be described. However, since the cooling water temperature control system according to the present embodiment is configured in the same manner as the cooling water temperature control system according to the first embodiment, description regarding the configuration is omitted.

  In the cooling water temperature control system according to the present embodiment, the target increase amount is determined from the magnitude relationship between the heat generation amount of the engine 10 and the required heat amount for heating the cooling water. Thus, by considering the balance between the heat generation amount of the engine 10 and the required heat amount for heating the cooling water, it is determined whether or not the heat generation amount increase control of the engine 10 is necessary with higher accuracy. Because it can.

  Hereinafter, a control process for increasing the coolant temperature, which is executed in the coolant temperature control system according to the present embodiment, will be described with reference to the flowchart of FIG. The basic process for determining the target increase amount is the same for both the cooling water temperature control system according to the first embodiment and the cooling water temperature control system according to the second embodiment. That is, even in the cooling water temperature control system according to the second embodiment, when it is necessary to increase the cooling water temperature, the processing shown in the flowchart of FIG. 2 is executed. However, in that case, the target increase correction processing in step S150 is different from that of the first embodiment. The flowchart of FIG. 7 shows the details of the target increase correction process executed by the coolant temperature control system of the second embodiment. Hereinafter, the target increase correction process according to the present embodiment will be described.

  First, in step S210, the engine load is evaluated by calculating or estimating the engine load. For example, it is also possible to estimate the engine load within a certain future time on the assumption that the same engine load will continue in the future using information on the past engine load (torque, rotation speed). Further, when the vehicle is equipped with a navigation device and route guidance is performed by the navigation device, the future engine load may be estimated based on the route. The latter example will be described in more detail with reference to the flowchart of FIG.

  In step S300, a destination setting process is executed. In step S310, the route to the set destination is calculated. In subsequent step S320, traffic jam information is acquired from a traffic information providing system such as VICS (registered trademark). In step S330, information related to the vehicle speed when the vehicle travels on the set route (stop time, acceleration / deceleration, average vehicle speed, etc.) is predicted and calculated in consideration of traffic jam information. The processing so far is executed in the navigation device. Then, in the coolant temperature control ECU 20, the process of step S340 is executed, and the state (torque, rotation speed) of the engine 10 is estimated based on the information related to the predicted vehicle speed. When the target vehicle is a hybrid vehicle, the operating state of the engine is maintained at an efficient operating point, and the operating point may be estimated.

  In this way, after the engine load is evaluated, in step S220, when the engine 10 is operated so as to generate an engine output corresponding to the engine load, the amount of heat generated in the engine 10 is calculated. For example, the heat generation amount of the engine can be calculated by using a map of the heat generation amount with respect to the state (torque, rotation speed) of the engine 10 and integrated to calculate the heat generation amount of the engine. Further, when the target vehicle is a hybrid vehicle, the heat generation amount with respect to the operating point is obtained from a map, and the heat generation amount can be calculated by integrating the obtained amount.

  In the subsequent step S230, a required heat amount for heating the cooling water is calculated. This required heat quantity is calculated as a heat quantity that is the sum of the heat quantity consumed for heating, the heat quantity for obtaining the minimum amount of increase in the cooling water temperature, and the heat quantity naturally radiated. The amount of heat consumed for heating can be calculated based on the outside air temperature, the passenger compartment temperature, and the set temperature. In order to improve accuracy, the vehicle speed, the amount of solar radiation, the number of passengers, etc. may be taken into consideration. Moreover, you may estimate the heat amount consumed for heating from the past heat consumption. For example, the heat consumption amount of heating may be calculated on the assumption that the past heat consumption amount is maintained. The past heat consumption can be calculated based on the cooling water temperature and the flow velocity.

  In step S240, the heat generation amount of the engine 10 is compared with the required heat amount for heating the cooling water. In this comparison process, when it is determined that the heat generation amount is equal to or greater than the required heat amount, it is predicted that the cooling water is sufficiently heated. Therefore, there is little need to execute the calorific value increase control. Therefore, a negative correction value is calculated as a correction value for correcting the target increase amount in step S250 so that the heat generation amount increase control is less likely to be executed. For example, the negative correction value can be calculated by subtracting the heat generation amount from the required heat amount and multiplying the subtraction result by a predetermined first coefficient. On the other hand, when it is determined that the heat generation amount is less than the required heat amount, it is predicted that heating of the cooling water will be insufficient. Therefore, the heat generation amount increase control is more easily performed, and as a result, in step S260, a positive correction value is calculated as a correction value for correcting the target increase amount so that heating of the cooling water temperature is promoted. To do. For example, the positive correction value can be calculated by subtracting the heat generation amount from the required heat amount and multiplying the subtraction result by a predetermined second coefficient.

  In step S270, the target increase amount is corrected by the correction value calculated in step S250 or S260, and the final target increase amount is determined.

  In the present embodiment, the example in which the cooling water temperature control system determines the target increase amount from the magnitude relationship between the heat generation amount of the engine 10 and the required heat amount for heating the cooling water has been described. However, in general, when the predicted engine load is high, the heat generation amount of the engine increases compared to the case where the engine load is lower than that, and as a result, the temperature of the coolant temperature also increases. It can be said that it becomes easy. For this reason, the target increase amount may be corrected directly from the load of the engine 10 without performing a process such as comparison with the required heat amount of the cooling water heating. Specifically, when the calculated engine load is high, the target increase amount of the cooling water temperature may be made relatively small as compared with a case where the engine load is lower than that. When the engine load is high, there is a high possibility that the temperature of the cooling water will eventually rise to the target value without executing the heat generation increase control. Therefore, when the engine load is high, the target increase amount of the cooling water temperature is made relatively small so that the heat generation amount increase control becomes difficult to be executed. it can.

(Third embodiment)
Next, a cooling water temperature control system according to a third embodiment of the present invention will be described. However, since the cooling water temperature control system according to the present embodiment is configured in the same manner as the cooling water temperature control system according to the first embodiment, description regarding the configuration is omitted. Further, as in the case of the second embodiment, the basic process for determining the target increase amount is the same as that of the first embodiment in the present embodiment, and the description thereof is also omitted. .

  The cooling water temperature control system according to the present embodiment is characterized in that the final target increase amount is determined by correcting the target increase amount based on the actually detected increase amount of the cooling water temperature. There is. Hereinafter, the target increase correction process in the present embodiment will be described with reference to the flowchart of FIG.

  First, in step S400, the current cooling water temperature is detected based on the detection signal of the water temperature sensor 22. In the subsequent step S410, the actual amount of increase in the coolant temperature per unit time is calculated based on the current coolant temperature, the coolant temperature detected in the past, and the elapsed time between the two detection points.

  In step S420, a correction value is calculated according to the calculated actual increase amount. That is, when the actual increase amount is large, the correction amount is calculated so that the finally determined target increase amount of the cooling water temperature is smaller than when the actual increase amount is smaller than that. For this purpose, for example, the actual increase amount of the cooling water temperature is compared with a predetermined increase amount threshold value, and when the actual increase amount is larger than the predetermined increase amount threshold value, it is determined according to the difference. If the actual increase amount of the cooling water temperature is smaller than the increase amount threshold value, the determined target increase amount is increased according to the difference. It may be corrected as follows. In step S430, the target increase amount is corrected by the calculated correction value, and the final target increase amount is determined.

  As described above, the reason for calculating the correction value is as follows. In other words, when the calculated actual increase amount is relatively large, the temperature of the cooling water is likely to increase thereafter. Therefore, the target increase amount of the cooling water temperature is relatively reduced so that the heat generation amount increase control of the engine 10 is difficult to be executed. Thereby, it can suppress reliably that fuel is consumed wastefully.

  Further, an actual increase amount of at least two types of cooling water temperatures having different unit times is calculated, and a difference between the two types of increase amount threshold values respectively set for the actual increase amounts of the two types of cooling water temperatures. Depending on, two types of correction values may be calculated. In this way, when the actual amount of increase is calculated by varying the unit time, the target amount of increase increases unnecessarily when the amount of increase is large in the long term even if the amount of increase is small in the short term. Correction can be suppressed.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the second and third embodiments, when calculating the correction value for the target increase amount, the correction value for which the corrected target increase amount (the finally determined target increase amount) is zero or negative May be calculated. This is because it is possible to make it difficult for the engine heat generation amount increase control to be executed.

10 Engine 14 Pump 16 Radiator 18 Radiator Fan 20 Cooling Water Temperature Control ECU
22 Water temperature sensor 24 Outside air temperature sensor 26 Crank angle sensor 28 Throttle opening sensor 30 Vehicle speed sensor

Claims (12)

Temperature detection means (22) for detecting the temperature of the cooling water of the engine;
Target value setting means (S100) for setting the target value of the cooling water temperature;
A target increase amount for determining a target increase amount of the coolant temperature per unit time when the coolant temperature detected by the temperature detection means is lower than the coolant temperature target value set by the target value setting means Determining means (S140, S150);
Control means for controlling the engine so that the amount of heat generated by the engine increases when the amount of increase in the coolant temperature detected by the temperature detection means per unit time is smaller than the target increase amount ( S164). , S172 , S190) ,
The control means calculates a target temperature corresponding to the target increase amount based on an elapsed time after the target increase amount is determined, and the cooling water temperature detected by the temperature detection means becomes the target temperature. If not, it is determined that the amount of increase in the cooling water temperature per unit time is smaller than the target amount of increase . Said control means calculates a target temperature in accordance with the target amount of increase, the cooling water temperature control system according to claim 1, characterized in that as the elapsed time becomes longer, have a large radium. The cooling water is used as a heat source for heating the passenger compartment,
The target increase amount determining means, whether the operation of the apparatus for performing the vehicle interior heating, and in accordance with at least one type of operation mode during operation, according to claim 1 or, wherein the determining the target increase amount coolant temperature control system according to 2. The target increase amount determining means, when the device that performs the vehicle interior heating is operating, compared to when not operating, according to claim 3, characterized in that to increase the target increase amount Cooling water temperature control system. The apparatus for heating the passenger compartment has an eco mode and a comfort mode as operation modes,
4. The cooling water according to claim 3 , wherein when the comfort mode is selected, the target increase amount determination unit increases the target increase amount compared to when the eco mode is selected. Temperature control system. Based on at least one of the temperature difference between the heating set temperature and the passenger compartment temperature and the temperature difference between the heating set temperature and the outside air temperature, the target increase amount determining means increases as the temperature difference increases. The cooling water temperature control system according to any one of claims 3 to 5 , further comprising target increase amount correction means (S150) for correcting the determined target increase amount. Temperature detection means (22) for detecting the temperature of the cooling water of the engine;
Target value setting means (S100) for setting the target value of the cooling water temperature;
A target increase amount for determining a target increase amount of the coolant temperature per unit time when the coolant temperature detected by the temperature detection means is lower than the coolant temperature target value set by the target value setting means Determining means (S140, S150);
Control means (S170) for controlling the engine so that the amount of heat generated by the engine increases when the amount of increase in cooling water temperature detected by the temperature detection means per unit time is smaller than the target increase amount. , S190)
Comprising a load detecting means (S210) for calculating or estimating the load of the engine,
When the engine load calculated or estimated by the load detection unit is high, the target increase amount determination unit relatively decreases the target increase amount of the coolant temperature compared to a case where the engine load is lower than that. cooling water temperature control system that is characterized in that. Temperature detection means (22) for detecting the temperature of the cooling water of the engine;
Target value setting means (S100) for setting the target value of the cooling water temperature;
A target increase amount for determining a target increase amount of the coolant temperature per unit time when the coolant temperature detected by the temperature detection means is lower than the coolant temperature target value set by the target value setting means Determining means (S140, S150, S240-S270);
Control means (S170) for controlling the engine so that the amount of heat generated by the engine increases when the amount of increase in cooling water temperature detected by the temperature detection means per unit time is smaller than the target increase amount. , S190)
Load detection means (S210) for calculating or estimating the load of the engine;
A calorific value calculating means (S220) for calculating a calorific value generated in the engine when the engine is operated so as to generate an engine output corresponding to the engine load calculated or estimated by the load detecting means;
Wherein the required heat amount estimating means for estimating a required amount of heat for heating the cooling water (S230), the above target increased amount determination hand stage with a heating value of the calorific value calculation means has calculated, the heat value demand estimating means There is greater than the required heat amount estimated is the as compared with the case the request is smaller than the amount of heat, cooling water temperature control system that is characterized in that relatively small target increased amount of the cooling water temperature . When the heat generation amount is larger than the required heat amount, the target increase amount determination means corrects the determined target increase amount to be small according to the difference, and the heat generation amount is the required heat amount. 9. The apparatus according to claim 8 , further comprising target increase amount correction means (S250 to S270) for correcting the determined target increase amount so as to increase in accordance with the difference when the heat amount is smaller than the heat amount. Cooling water temperature control system. Temperature detection means (22) for detecting the temperature of the cooling water of the engine;
Target value setting means (S100) for setting the target value of the cooling water temperature;
A target increase amount for determining a target increase amount of the coolant temperature per unit time when the coolant temperature detected by the temperature detection means is lower than the coolant temperature target value set by the target value setting means Determining means (S140, S150, S410 to S430);
Control means (S170) for controlling the engine so that the amount of heat generated by the engine increases when the amount of increase in cooling water temperature detected by the temperature detection means per unit time is smaller than the target increase amount. , S190), and
The target increase amount determining hands stage, from the cooling water temperature detected by said temperature detecting means, calculates an actual increase of the cooling water temperature per unit time, when the actual increase amount is large, it compared to smaller than, cooling water temperature control system that is characterized in that relatively small target increased amount of the cooling water temperature. The target increase amount determination means corrects the determined target increase amount to be small according to the difference when the actual increase amount of the cooling water temperature is larger than a predetermined increase amount threshold value. When the actual increase amount of the cooling water temperature is smaller than the increase amount threshold value, the target increase amount correction means (S420, S420 ) corrects the determined target increase amount so as to increase according to the difference . The cooling water temperature control system according to claim 10 , further comprising: S430) . The target increase amount determination means calculates an actual increase amount of at least two types of cooling water temperatures having different unit times,
The target increase amount correction means corrects the determined target increase amount according to a difference between the two types of increase amount threshold values set for the actual increase amounts of the two types of cooling water temperatures. The cooling water temperature control system according to claim 11.

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