JP2013100724A - Cooling device and cooling method of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device and a cooling method of an internal combustion engine by means of which even during various kinds of operational states of a vehicle or the internal combustion engine, the internal combustion engine can be put into an optimum condition, and a fuel economy, an exhaust gas performance, and an output performance can be improved by adequately controlling a cooling water pump for which requested contents are complicated and diversified.SOLUTION: The cooling device of the internal combustion engine includes a variable cooling water pump 13 of which the discharge rate can be changed even at the same engine speed, and a control device for controlling the variable cooling water pump 13. The control device controls the operation of the variable cooling water pump 13 divided into an idle operating state, a deceleration operating state, an acceleration operating state, and other normal operating state.

Description

  The present invention relates to a cooling device for an internal combustion engine having a variable cooling water pump and a cooling method for the internal combustion engine in an internal combustion engine such as an automobile engine or an industrial engine, and more specifically, according to the operating state of the internal combustion engine, The present invention relates to a cooling device for an internal combustion engine and a cooling method for the internal combustion engine that can improve the fuel efficiency of the internal combustion engine by controlling the cooling water pump so that the efficiency of the internal combustion engine is good and optimal.

  In recent years, exhaust gas regulations in automobile engines, industrial engines, and the like that use internal combustion engines have become stricter year by year. In addition to this, strict fuel efficiency regulations have been introduced in recent years as a countermeasure to global warming. In order to meet these requirements, the latest internal combustion engines (engines) have research and development to improve fuel efficiency by improving combustion in the cylinder, and research and development to improve fuel efficiency by reducing engine friction. Has also been done at the same time.

  However, since the improvement of the combustion efficiency in the engine body as a means for improving the fuel efficiency of the internal combustion engine has reached the limit, research and development for reducing the friction of the engine body has recently been activated. In particular, in this research on reducing engine friction, the conventional operation of the cooling water pump (water pump) is problematic in that it is wasteful and does not achieve the optimum work required by the internal combustion engine. It has become.

  That is, normally, the cooling water pump used in the internal combustion engine is connected to the engine drive unit by a gear, a belt, or the like, and is rotationally driven by directly transmitting the power of the engine drive unit. Therefore, generally, the rotation speed of the cooling water pump increases in proportion to the engine rotation speed.

  On the other hand, the cooling water is supplied to each part that needs to be cooled in order to cool each part of the internal combustion engine. The specification of the cooling water pump and the selection of the flow rate are the most severe engine in the operation of the internal combustion engine. This is based on full load operating conditions. Therefore, considering the optimum flow rate of the cooling water required for the internal combustion engine, it is optimal that the flow rate of the cooling water is adjusted according to each engine speed and each engine load. However, in the current cooling water pump, since the amount of cooling water supplied is determined according to the engine speed, depending on the operating state of the internal combustion engine, a wasteful work is performed. It has become important to reduce this wasteful work and improve fuel efficiency.

  For this reason, attention has been paid to the improvement of fuel consumption by “variation of the cooling water pump” that enables the discharge amount of the cooling water pump to be changed even at the same engine speed. Devices and systems have been developed. For example, an electric cooling water pump in which a motor is rotated using electricity as a driving force, and a cooling water pump is attached to the tip of the motor to rotate the wings. A mechanical variable cooling water pump that covers the wings of a normal mechanical cooling water pump with a metal plate to change the amount of work, and a machine that divides the cooling water channel into several parts and arranges thermostats with different temperature settings for each. Type variable cooling water system.

  In this connection, the flow rate of the cooling fluid flowing into the water jacket is the normal flow rate when the engine is in an extremely cold state, and is lost or less than the normal flow rate when the engine is in a cold state. There has been proposed an engine cooling device that reduces the normal flow rate when the engine is in a warm state and allows the heater path to flow at least when the engine is in an extremely cold state (for example, Patent Documents). 1).

  As described above, the development of the variable cooling water pump is advancing. On the other hand, the flow rate of the cooling water required for the cooling water pump by each device attached to the internal combustion engine is also complicated. Various contents required for this cooling water pump are related to "fuel consumption", "exhaust gas performance", and "output performance", and optimal operation control of the cooling water pump is required to improve these. .

  In order to improve the “fuel consumption”, it is necessary to stop the operation of the useless cooling water pump and reduce the engine friction for driving the cooling water pump. Further, it is necessary to reduce the engine friction by rapidly increasing the temperature of the internal combustion engine and lowering the viscosity of the circulating oil. From this aspect, it is necessary to optimally control the cooling water pump.

  In terms of “exhaust gas performance”, the EGR system plays an important role in meeting the recent severe exhaust gas regulations in internal combustion engines. . Therefore, in order to appropriately perform EGR for ensuring high exhaust gas performance, it is necessary to efficiently cool the EGR cooler, and also from this aspect, optimum control of the cooling water pump is necessary.

  Furthermore, with regard to “output performance”, recent internal combustion engines are actively competing for development of internal combustion engines with high fuel efficiency, and one of them is that the internal combustion engine with a small displacement is increased in output. The organization is downsizing. Thereby, it becomes possible to mount a small-sized internal combustion engine with small engine friction instead of a large-sized internal combustion engine with large engine friction, and to achieve fuel efficiency reduction. Specifically, the fuel efficiency can be improved by drawing the full load performance curve of the internal combustion engine that has achieved higher output above the full load performance curve of the conventional internal combustion engine.

  However, there is a problem that the temperature of each part of the engine rises as the engine load increases. That is, it is required to increase the flow rate of the cooling water in an engine high load state by increasing the engine output. On the other hand, when the size of the cooling water pump is simply increased while satisfying this requirement, there arises a problem that fuel consumption deteriorates. Another problem is that the starting performance is insufficient because the internal combustion engine is downsized. In other words, there is a demand for reducing engine friction as much as possible when starting. Furthermore, in order to supply to the auxiliary brake device that enhances the braking force of the vehicle, the cooling water pump needs to be increased in pressure and flow rate. There is also the problem of being.

  In other words, the cooling water pump is becoming more variable, but the contents required for the cooling water pump are complicated and diversified, and the internal combustion engine is operated in an optimal state even in various operating states of the vehicle and the internal combustion engine. In spite of the necessity of controlling the cooling water pump for this purpose, there is a problem that the current internal combustion engine cooling apparatus and internal combustion engine cooling method cannot cope with these complicated controls.

JP 2006-266196 A

  The present invention has been made in view of the above-described situation, and its object is to appropriately control various cooling water pumps whose required contents are complicated and diversified, thereby performing various operations of vehicles and internal combustion engines. A cooling device for an internal combustion engine and a cooling method for the internal combustion engine that can bring the internal combustion engine into an optimal state even in a state, and can improve fuel efficiency, exhaust gas performance, and output performance There is to do.

  In order to achieve the above object, a cooling apparatus for an internal combustion engine of the present invention includes a variable cooling water pump capable of changing a discharge amount even at the same engine speed and a control device for controlling the variable cooling water pump. In the cooling device for an internal combustion engine, the control device is configured to control the operation of the variable coolant pump separately for an idle operation state, a deceleration operation state, an acceleration operation state, and other normal operation states.

  The variable cooling water pump is not only proportional to the engine rotation speed but also ON (operation) -OFF (operation stop) or the discharge amount even if the engine rotation speed is the same. This is a cooling water pump that can change the temperature, and an electromagnetic clutch cooling water pump that can be turned on and off by providing an electromagnetic clutch at the tip of the cooling water pump. A cooling water pump (electric cooling water pump), a mechanical variable cooling water pump provided with a transmission between the drive shaft of the internal combustion engine and the cooling water pump, or the like can be used. Therefore, the change in the discharge amount of the variable cooling water pump here includes ON-OFF of the variable cooling water pump.

  According to this configuration, the discharge amount of the variable cooling water pump can be finely changed in accordance with various operating states of the internal combustion engine, so that comprehensive control of the variable cooling water pump that is optimal for the internal combustion engine can be performed. It is possible to improve fuel efficiency, exhaust gas performance, and output performance.

  Further, in the internal combustion engine cooling apparatus, the variable cooling water pump is formed of a variable cooling water pump capable of increasing or decreasing the discharge amount, and the control device is configured to detect a temperature at which the internal combustion engine is overheated in the normal operation state. When the measured temperature of the sensor is equal to or lower than a first determination temperature set in advance, the variable cooling water pump is set to the first operation state, and when the measured temperature exceeds the first determination temperature, the variable cooling is performed. When normal operation control is performed to increase the discharge amount of the water pump from the first operation state, and in the idle operation state, the measured temperature is equal to or lower than a second determination temperature set in advance higher than the first determination temperature The variable cooling water pump is set to the first operating state, and when the measured temperature exceeds the second determination temperature, the discharge amount of the variable cooling water pump is increased from that of the first operating state. In the decelerating operation state, the variable cooling water pump is set to the first operation state when there is fuel injection, and when there is no fuel injection, the variable cooling water pump is controlled. Control is performed during deceleration operation in which the discharge amount is increased from that in the first operation state. In the acceleration operation state, when the measured temperature is equal to or lower than a preset third determination temperature, the variable coolant pump is In addition to the one operating state, when the measured temperature exceeds the third determination temperature, the control is performed during acceleration operation in which the discharge amount of the variable cooling water pump is increased from that in the first operating state. .

  The second determination temperature and the third determination temperature are each set to a temperature higher than the first determination temperature, but the third determination temperature is set without being related to the second determination temperature. Therefore, the third determination temperature may be the same as or different from the second determination temperature. The first operating state is an operating state of the variable cooling water pump for circulating the cooling water with the minimum amount of cooling water in the operation of the internal combustion engine, and is set in advance by the time of determination of the measured temperature. It is a driving state.

  In addition, when there are a plurality of temperature sensors that detect the overheating state of the internal combustion engine, the temperatures detected by these temperature sensors are compared with the judgment temperatures set in advance for the respective temperature sensors, and one of them is detected. If one, some, or all of the following are the following, it is determined that the temperature of the temperature sensor that detects the overheating state of the internal combustion engine is equal to or lower than a preset determination temperature. Further, when it is not determined that the temperature is equal to or lower than the determination temperature, it is determined that the temperature is higher than the determination temperature.

  It should be noted that this determination is determined to be lower than the determination temperature when one of the temperatures of these temperature sensors is lower than the determination temperature, or some of the temperatures of these temperature sensors are respectively determined. Whether or not it is determined that the temperature is lower than the determination temperature or whether the temperature of all of these temperature sensors is equal to or lower than each determination temperature is not particularly limited in the present invention. This control is set in advance.

  According to this configuration, in the normal operation state, the variable cooling water pump can be brought into the first operation state when the measured temperature of the temperature sensor that detects the overheat state of the internal combustion engine is equal to or lower than the first determination temperature set in advance. Aim to improve fuel efficiency as much as possible.

  Even in the idling operation state, when the measured temperature is equal to or lower than the second determination temperature, the temperature of the entire engine is unlikely to rise rapidly. Therefore, the variable cooling water pump is set to the first operation state and fuel consumption is as much as possible. Aim to improve.

  Further, in the deceleration operation state, when there is fuel injection, the fuel necessary for maintaining the rotation of the internal combustion engine and for driving accessories (friction) such as an oil pump is being injected, When there is fuel injection, it is better not to rotate the variable cooling water pump as much as possible. Therefore, the variable cooling water pump is set to the first operating state to reduce engine friction and reduce fuel consumption. Further, when there is no fuel injection, the variable cooling water pump does not affect the fuel consumption even if the discharge amount of the variable cooling water pump is increased from the first operating state, and also for reducing damage to the internal combustion engine. The time to reach the temperature limit in the next operating state (for example, acceleration) as much as the temperature decreased by cooling, while the cooling water is circulated to stabilize the temperature of the entire engine, That is, since the time until the cooling pump is rotated is increased, the fuel consumption can be improved.

  Further, in the acceleration operation state, when the measured temperature is equal to or lower than the third determination temperature, the engine cooling is reduced by setting the variable cooling water pump to the first operation state to improve the vehicle starting power performance, acceleration performance, and fuel consumption. Can do.

  However, even when the internal combustion engine is in each operating state, if the measured temperature exceeds each judgment temperature, the discharge amount of the variable cooling water pump is increased from the first operating state to cool the internal combustion engine. Prioritize.

  Furthermore, in the cooling device for an internal combustion engine, the discharge amount of the variable cooling water pump is increased or decreased by turning the variable cooling water pump on and off, and the operation of the variable cooling water pump is performed in the first operation state. When in the OFF state, the same effect can be obtained by using a variable cooling water pump having a simple configuration of ON-OFF control.

  And the cooling method of the internal combustion engine of the present invention for achieving the above object is the operation of the internal combustion engine even when the discharge amount of the variable coolant pump provided in the cooling device of the internal combustion engine is the same engine speed. A method of cooling an internal combustion engine that can change depending on a state, wherein the operation of the variable cooling water pump is controlled by being divided into an idle operation state, a deceleration operation state, an acceleration operation state, and other normal operation states. is there.

  In the internal combustion engine cooling method, the variable cooling water pump is controlled by increasing or decreasing the discharge amount, and in the normal operation state, a measurement temperature of a temperature sensor for detecting an overheat state of the internal combustion engine is preset. When the temperature is equal to or lower than the first determination temperature, the variable cooling water pump is set to the first operation state, and when the measured temperature exceeds the first determination temperature, the discharge amount of the variable cooling water pump is set to the first amount. Control during normal operation that increases more than the operating state is performed, and in the idle operating state, the variable cooling water pump is turned on when the measured temperature is equal to or lower than the second determination temperature set in advance higher than the first determination temperature. In the first operation state, when the measured temperature exceeds the second determination temperature, the discharge amount of the variable cooling water pump is increased from the first operation state, and in the deceleration operation state, fuel injection is performed. In some cases, the variable cooling water pump is set to the first operation state, and when fuel injection is lost, the discharge amount of the variable cooling water pump is increased from the first operation state, and the acceleration operation state is set. Then, when the measured temperature is equal to or lower than a preset third judgment temperature, the variable cooling water pump is set to the first operating state, and the measured temperature exceeds a preset third judgment temperature. The discharge amount of the variable cooling water pump is increased from that in the first operating state.

  Furthermore, in the cooling method for an internal combustion engine, the discharge amount of the variable cooling water pump is increased or decreased by turning the variable cooling water pump on and off, and the operation of the variable cooling water pump is performed in the first operating state. Set to the OFF state.

  According to these internal combustion engine cooling methods, the same operational effects as the above-described internal combustion engine cooling apparatus can be obtained.

  According to the internal combustion engine cooling apparatus and internal combustion engine cooling method according to the present invention, in addition to temperature control using a thermostat or the like, the variable cooling water pump is operated in an idle operation state, a deceleration operation state, an acceleration operation state, and others. Therefore, the overall control controls the cooling effect for each part of the internal combustion engine and the driving force of the variable cooling water pump necessary for this cooling into the operating state of the internal combustion engine. Together, it can be in an optimal state.

  Therefore, in various operating states of the vehicle and the internal combustion engine, it is possible to cope with the complicated and diversified supply of the cooling water by appropriately controlling the variable cooling water pump, thereby improving the fuel consumption of the internal combustion engine. In addition, exhaust gas performance and output performance can be improved.

It is a figure which shows the structure of the cooling water channel of the internal combustion engine of embodiment of this invention. It is a figure which shows an example of the control flow of the cooling method of the internal combustion engine of 1st Embodiment of this invention. It is a figure which shows an example of the control flow of the cooling method of the internal combustion engine of 2nd Embodiment of this invention. It is a figure which shows the operation instruction | indication (1) and operation stop (0) of the variable cooling water pump in a deceleration state.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an internal combustion engine cooling apparatus and an internal combustion engine cooling method according to embodiments of the present invention will be described with reference to the drawings. The present invention is applicable not only to a diesel engine mounted on a vehicle but also to other internal combustion engines such as other internal combustion engines mounted on a vehicle, industrial internal combustion engines, and internal combustion engines for power generation.

  FIG. 1 shows an example of the configuration of a cooling water passage of an internal combustion engine (engine). The cooling water enters the oil cooler 14 from the cooling water tank 11 via the cooling water supply path 12 by the variable cooling water pump 13, and is variably cooled by the thermostat 15 via the cooling water flow path 16 and the radiator 17 according to the cooling water temperature. It returns to the water pump 13 or returns to the variable cooling water pump 13 via the cooling water pool 18 without passing through the cooling water flow path 16 and the radiator 17. A part of the cooling water cools the oil cooler 14, then enters the EGR cooler 20 via the cooling water passage 19, and returns to the variable cooling water pump 13 via the cooling water passage 21. The cooling water pool 18 and the EGR cooler 20 are provided with air venting pipes 22 and 23.

  In the internal combustion engine cooling apparatus and internal combustion engine cooling method according to the first embodiment of the present invention, the variable coolant pump 13 is configured to be capable of ON-OFF control. Specifically, it is constituted by a variable cooling water pump 13 of an electromagnetic clutch type cooling water pump in which an electromagnetic clutch is attached to the tip of a general cooling water pump.

  This electromagnetic clutch type variable cooling water pump is an electromagnetic clutch used in a compressor of an internal combustion engine attached to a drive shaft of the cooling water pump. A magnet installed in the electromagnetic clutch is activated by an electric signal. This is a device in which the magnet plate sucks and the main body operates, and the variable cooling water pump 13 can be turned on and off at the same engine speed. In this electromagnetic clutch variable cooling water pump, only two patterns of ON circulation operation and OFF circulation stop are operated, and in the case of OFF operation stop, the cooling water does not circulate.

  Further, in order to grasp in detail the temperature and performance of the internal combustion engine, a temperature sensor is provided in a portion where cooling of the internal combustion engine is important and the temperature is measured, and the variable cooling water pump 13 is turned on based on the measured temperature. -Configure to control OFF. Examples of the temperature sensor include a cooling water temperature sensor, a circulating oil temperature sensor, an exhaust gas temperature sensor, an EGR cooling water temperature sensor, an exhaust gas temperature sensor, a head temperature sensor, and a body temperature sensor.

  If a temperature sensor is provided in the EGR cooler and the variable cooling water pump 13 is controlled to be turned on and off based on the measured temperature, a high EGR rate can be maintained and NOx generated by combustion in the cylinder can be maintained. The generation amount can be reduced, and the exhaust gas performance can be improved.

  In other words, internal combustion engines have parts that want to lower the temperature quickly, and conversely, they also serve as temperature limit conditions. The location and temperature are clarified and used for control.

  Further, for the control of the variable coolant pump 13 required in accordance with various operation modes of the internal combustion engine, a control map is set in advance with detection results of each sensor provided in each part of the internal combustion engine. By performing fine control according to each operation mode while referring to FIG. 6, it becomes possible to improve the fuel consumption of the internal combustion engine, the exhaust gas performance, and the power performance.

  The control device for controlling the variable cooling water pump 13 divides the operation of the variable cooling water pump 13 into the idle operation, the deceleration operation, the acceleration operation, and the other normal operation, and the overheated state of the internal combustion engine. It is configured to control the temperature measured by the temperature sensor for detecting the temperature while being set in advance or compared with each preset determination temperature.

  When there are a plurality of temperature sensors for detecting the overheat state of the internal combustion engine, the temperature detected by these temperature sensors is compared with a judgment temperature preset for each temperature sensor, and one of them is detected. Alternatively, when some or all of them are equal to or lower than the respective determination temperatures, it is determined that the measured temperature of the temperature sensor that detects the overheat state of the internal combustion engine is equal to or lower than a predetermined determination temperature. Further, when it is not determined that the temperature is equal to or lower than the determination temperature, it is determined that the temperature is higher than the determination temperature.

  As this determination, there are the following three determination methods. First, when one of the temperatures of these temperature sensors becomes equal to or lower than the determination temperature, it is determined to be equal to or lower than the determination temperature. Second, when some of the temperatures of these temperature sensors are below the respective judgment temperatures, the temperature is judged to be below the judgment temperature. Third, when all of the temperatures of these temperature sensors are below the respective determination temperatures, it is determined that the temperature is below the determination temperature. Which of these determination methods is selected depends on the internal combustion engine, but in actual control, it is necessary to select one of the determination methods in advance and set a determination criterion such as a determination temperature calculation method corresponding thereto. There is.

  This internal combustion engine cooling method will be described with reference to the control flow of FIG. The control flow of FIG. 2 is called and executed from the upper control flow when the internal combustion engine is started. When the operation of the internal combustion engine is stopped, an interrupt occurs and the control flow returns to the upper control flow. It is shown as ending with the end of the flow.

  When the operation of the internal combustion engine is started, the control flow in FIG. 2 is called together with this, and this control flow starts. In step S11, various information on the engine is acquired. Among the various types of information, there are the engine speed, the fuel injection amount, the measured temperature Tm that is the detection value of the temperature sensor that detects the overheating state of the internal combustion engine, and the like.

  The control device performs control by dividing into an idle operation state, a deceleration operation state, an acceleration operation state, and other normal operation states. Therefore, it is determined whether or not there is an idle operation state in step S12 of the control flow of FIG. 2, whether or not it is in a deceleration operation state in step S13, and whether or not it is in an acceleration operation state in step S14. And do. If all of the determinations in steps S12, S13, and S14 are negative (NO), it is determined that the operation is in the normal operation state, the process proceeds to step S15, and control during normal operation is performed.

  In this step S15, it is determined whether or not the measured temperature Tm is equal to or lower than a preset first determination temperature Ta. If the measured temperature Tm is equal to or lower than the first determination temperature Ta (YES), the process proceeds to step S20. Then, the electromagnetic clutch is turned off to stop the operation of the variable cooling water pump 13, that is, the variable cooling water pump 13 is turned off, and the process returns to step S11.

  If the measured temperature Tm exceeds the first determination temperature Ta in step S15 (NO), go to step S30 and refer to a preset control map based on the detected values of the engine speed and the fuel injection amount. Then, the electromagnetic clutch is turned on and off to control the variable cooling water pump 13 to operate and stop operation, and the process returns to step S11.

  In the normal operation control of step S15, when the measured temperature Tm exceeds the first determination temperature Ta (NO), according to the engine operating state determined by the engine speed and the fuel injection amount in step S30, The time of the ON / OFF operation of the electromagnetic clutch is adjusted, and the operation time and stop time of the variable cooling water pump 13 are adjusted. That is, the variable cooling water pump 13 is controlled in accordance with the operation state of the internal combustion engine and the state at that time by using the “steady-state stop period map” or the like for normal operation control used for this operation state. And aim to reduce fuel consumption as much as possible.

  In this normal operation control, a basic engine control map is input to the control device, and during operation of the internal combustion engine, an engine speed (engine speed) is detected from an engine speed sensor (not shown), and the fuel is Detecting the injection amount, refer to the variable coolant pump control map based on the basic engine control map set in advance based on the test result, measurement result, calculation simulation result, etc. The operation of the variable cooling water pump 13 is operated by calculating ON / OFF of the clutch.

  These variable cooling water pump control maps (basic maps) provide a control system that can be operated in an optimum state for the internal combustion engine. In this control, the variable cooling water pump control map can be effectively used to operate the variable cooling water pump 13, and each part of the internal combustion engine 1 can be cooled with a necessary and sufficient cooling water flow rate. It becomes like this.

  In other words, a temperature sensor is provided in a portion where cooling of the internal combustion engine 1 is important, the temperature is measured, and control is performed to increase or decrease the discharge amount of the variable cooling water pump 13 based on the temperature. Since each part of the internal combustion engine 1 can be quickly cooled to the optimum state for the internal combustion engine 1 with the flow rate of the cooling water, the operating efficiency and cooling efficiency of the variable cooling water pump 13 can be improved, and fuel consumption can be improved. .

  Moreover, when it determines with it being an idle driving | running state by determination of step S12 (YES), it goes to step S12a and performs control at the time of idle driving | running | working. In step S12a, it is determined whether or not the measured temperature Tm is equal to or lower than a preset second determination temperature Tb. The second determination temperature Tb is set to a temperature higher than the first determination temperature Ta. If the measurement temperature Tm is equal to or lower than the second determination temperature Tb in this determination (YES), the process goes to step S20 to perform control to turn off the electromagnetic clutch and stop the operation of the variable coolant pump 13, and return to step S11. . If the measurement temperature Tm exceeds the second determination temperature Tb (NO) in step S12a, control is performed to turn on the variable cooling water pump 13 in step S30, and the process returns to step S11.

  In this idling operation state, the temperature of the entire internal combustion engine is unlikely to rise significantly, so when the measured temperature Tm is equal to or lower than the second determination temperature Tb, the variable cooling water pump 13 is turned off and the fuel consumption is reduced as much as possible.

  If it is determined in step S13 that the engine is not in the deceleration operation state (NO), or if it is determined that the fuel injection amount is not zero (NO), the process goes to step S14, where the fuel cell is in the deceleration operation state and the fuel. If it is determined that the injection amount is zero (YES), the control at the time of deceleration operation is performed, the control to turn on the variable cooling water pump 13 at step S30, the variable cooling water pump 13 is operated, and the step is performed. Return to S11. An example of a control map of the electromagnetic clutch used in this deceleration operation state is shown in FIG. “1” display indicates ON, and “0” display indicates OFF.

  When there is no fuel injection in this deceleration operation state, there are many states when the vehicle is decelerated or the vehicle is braked to operate the engine brake, so the control device actually instructs the fuel injection device of the internal combustion engine. By using the fuel injection amount, it is possible to grasp the deceleration state and the braking state of the vehicle to which fuel is not reliably injected, and the electromagnetic clutch is turned on to operate the variable coolant pump 13 to increase the braking force of the internal combustion engine. Can help.

  In other words, since cooling is basically necessary for an internal combustion engine, it is active in a state that does not affect fuel consumption except when the cooling water temperature is abnormally low, that is, when cooling is excessive. Then, the variable cooling water pump 13 is operated to suppress and stabilize the temperature increase of the internal combustion engine. If fuel injection is present in this deceleration operation state, the electromagnetic clutch is turned off in step S20 to stop the variable coolant pump 13 to reduce engine friction.

  Further, if it is determined in step S14 that the vehicle is in the acceleration operation state (YES), the process goes to step S14a to perform acceleration operation control. In this acceleration operation state, it is determined whether or not the measured temperature Tm is equal to or lower than a preset third determination temperature Tc. The third determination temperature Tc is set higher than the first determination temperature Ta, but is set independently of the second determination temperature Tb. Therefore, the third determination temperature Tc may be the same as or different from the second determination temperature Tb.

  If it is determined in step S14a that the measured temperature Tm is equal to or lower than the third determination temperature Tc (YES), control is performed to turn off the variable coolant pump 13 in step S20, and the process returns to step S11. When the measurement temperature Tm exceeds the third determination temperature Tc in the determination in step S14a (NO), control is performed to turn on the variable cooling water pump 13 in step S30, and the process returns to step S11.

  In determining whether or not the engine is in the acceleration operation state in step S14, the internal combustion engine is compared by comparing the amount of increase in the fuel injection amount with a threshold value, the comparison of the injection amount in the time before and after, or the like. Know the acceleration state of the. In addition, this acceleration determination is used as a trigger, and during this time from the acceleration determination time until a certain time (preset) elapses, it is determined that the state is “accelerated operation state”. May be.

  If it is determined in step S14 that the vehicle is in the accelerated operation state, the electromagnetic clutch is turned ON / OFF according to the measured temperature Tm, and the variable cooling water pump 13 is turned ON (operation) or OFF (operation stopped). That is, control for operating or stopping the variable coolant pump 13 is performed based on the determination of the acceleration operation state of the internal combustion engine and the determination of the measured temperature Tm.

  In the acceleration operation state, when the measured temperature Tm is equal to or lower than the third determination temperature Tc, the electromagnetic clutch is turned off and the variable coolant pump 13 is stopped to reduce the engine friction. And improve fuel economy. Further, when the measured temperature Tm is higher than the third determination temperature Tc in the acceleration operation state, the variable cooling water pump 13 is operated to supply the cooling water to increase the cooling capacity of the internal combustion engine. Thereby, sufficient cooling water is supplied to each part of the internal combustion engine in a high load state to prevent overheating.

  According to the control flow of FIG. 2, one of steps S11 to S20 and S11 to S30 is performed depending on the operating state of the internal combustion engine, the measured temperature Tm, and the presence or absence of the fuel injection amount, and then the process returns to step S11. Any one of S11 to S20 and S11 to S30 is repeated. Then, when the operation stop of the internal combustion engine is input, an interruption of step S40 occurs in the control flow of FIG. 2, the process returns to the upper control flow, and with the end of the upper control flow accompanying the stop of the internal combustion engine, The control flow in FIG. 2 is also terminated.

  According to the cooling method of the internal combustion engine carried out according to the control flow of FIG. 2, the variable cooling water pump 13 is finely operated (ON) or stopped (OFF) in accordance with various operating states of the internal combustion engine. Since the discharge amount of the cooling water pump 13 can be changed and the cooling water can be supplied to each part of the internal combustion engine such as an EGR cooler as needed, the overall variable cooling water pump 13 that is optimal for the internal combustion engine Control can be performed. Thereby, since the operating efficiency and cooling efficiency of the variable cooling water pump 13 are improved, fuel consumption can be improved. As a result, it is possible to improve fuel efficiency, exhaust gas performance, and output performance.

  Next, an internal combustion engine cooling device and an internal combustion engine cooling method according to a second embodiment will be described. In the internal combustion engine cooling apparatus and internal combustion engine cooling method of the second embodiment, the variable coolant pump 13 is discharged continuously or stepwise at the same engine speed, such as an electric coolant pump. Instead of turning the variable cooling water pump 13 off, instead of turning the variable cooling water pump 13 off, instead of turning on the variable cooling water pump 13, The point that the discharge amount of the variable coolant pump 13 is increased from the first operating state is different from the cooling device and the cooling method of the internal combustion engine of the first embodiment.

  With regard to the control flow, “switch the variable cooling water pump OFF” and S30 “turn the variable cooling water pump ON” in step S20 of the control flow of FIG. 2 of the cooling method for the internal combustion engine of the first embodiment. In the control flow of FIG. 3 for the cooling method of the internal combustion engine of the second embodiment, step S20A “sets the variable cooling water pump to the first operation state” and S30A “discharge amount of the variable cooling water pump to the first operation. It will be changed to “increased from state”.

  The first operation state of step S20A is an operation of the variable cooling water pump 13 for circulating the cooling water with the minimum amount of cooling water in the operation of the internal combustion engine, and is an operation state set in advance. Further, the control for increasing the discharge amount of the variable cooling water pump 13 in step S30A from the first operation state is control for increasing the discharge amount due to a change in the rotational speed of the variable cooling water pump 13 or the like.

  In addition, although the variable cooling water pump 13 can be selected as the first operating state of the control of the second embodiment, the state where the variable cooling water pump 13 is stopped (OFF) can be selected. In this case, the second embodiment However, the control of the second embodiment not only simply turns on the variable cooling water pump 13 but also increases the discharge amount of the variable cooling water pump 13 in the control of the second embodiment. It is possible to perform finer control, such as increasing or decreasing.

  Therefore, according to this configuration, the discharge amount of the variable cooling water pump 13 can be finely changed according to various operating states of the internal combustion engine, and necessary and sufficient cooling water is supplied to each part of the internal combustion engine such as an EGR cooler. Therefore, it is possible to perform comprehensive control of the variable coolant pump 13 that is optimal for the internal combustion engine. Thereby, since the operating efficiency and cooling efficiency of the variable cooling water pump 13 are remarkably improved, the fuel consumption can be remarkably improved. As a result, it is possible to further improve fuel consumption, exhaust gas performance, and output performance.

  According to the internal combustion engine cooling device and the internal combustion engine cooling method described above, in addition to temperature control using a thermostat or the like, the variable cooling water pump 13 is operated in an idle operation state, a deceleration operation state, an acceleration operation state, and other operations. Since control is performed separately for the normal operating state, these comprehensive controls make the cooling effect for each part of the internal combustion engine and the driving force of the variable cooling water pump necessary for this cooling match the operating state of the internal combustion engine. In an optimal state.

  In addition, the control of the variable cooling water pump 13 improves the fuel consumption at low temperature start and low temperature operation, improves the starting power performance and acceleration performance of the vehicle, improves the fuel consumption by reducing the warm-up time of the internal combustion engine, and accelerates. It is possible to improve the fuel consumption by reducing the work amount of the variable cooling water pump 13 using the determination, and improving the fuel consumption by actively operating the variable cooling water pump 13 in a deceleration state where fuel is not injected.

  The internal combustion engine cooling apparatus and internal combustion engine cooling method according to the present invention includes a variable cooling water pump operation in an idle operation state, a deceleration operation state, an acceleration operation state, and other normal operations in addition to temperature control using a thermostat or the like. The control is divided into states, and through these comprehensive controls, the cooling effect for each part of the internal combustion engine and the driving force of the cooling water pump necessary for this cooling are optimally matched to the operating state of the internal combustion engine. Therefore, it can be used in a wide range of internal combustion engines such as internal combustion engines mounted on automobiles, construction machinery, and power generation internal combustion engines.

11 Cooling water tank 12 Cooling water supply path 13 Variable cooling water pump 14 Oil cooler 15 Thermostat 17 Radiator 18 Cooling water pool 20 EGR cooler

Claims (6)

  In a cooling device for an internal combustion engine having a variable cooling water pump capable of changing a discharge amount even at the same engine speed and a control device for controlling the variable cooling water pump, the control device includes an idle operation state and a deceleration operation. A cooling apparatus for an internal combustion engine, which is configured to control the operation of the variable coolant pump separately for a state, an acceleration operation state, and a normal operation state other than that. The variable cooling water pump is formed with a variable cooling water pump that can increase or decrease the discharge amount,
The control device;
In the normal operation state, when the measured temperature of the temperature sensor for detecting the overheat state of the internal combustion engine is equal to or lower than the first determination temperature set in advance, the variable cooling water pump is set to the first operation state,
When the measured temperature exceeds the first determination temperature, performing a control during normal operation to increase the discharge amount of the variable cooling water pump from the first operation state,
In the idle operation state, when the measured temperature is equal to or lower than a second determination temperature set higher than the first determination temperature in advance, the variable cooling water pump is set to the first operation state, and the measured temperature is When the second determination temperature is exceeded, the idle operation control is performed to increase the discharge amount of the variable cooling water pump from the first operation state,
In the deceleration operation state, when there is fuel injection, the variable cooling water pump is set to the first operation state, and when fuel injection is not performed, the discharge amount of the variable cooling water pump is set to the first operation state. Control during deceleration operation that increases more than
In the accelerated operation state, when the measured temperature is equal to or lower than a preset third determination temperature, the variable cooling water pump is set to the first operation state, and the measured temperature exceeds the third determination temperature. 2. The cooling apparatus for an internal combustion engine according to claim 1, wherein in this case, the control is performed during acceleration operation in which the discharge amount of the variable cooling water pump is increased from the first operation state.   The discharge amount of the variable cooling water pump is increased or decreased by turning on and off the variable cooling water pump, and the operation state of the variable cooling water pump is turned off in the first operation state. Item 3. A cooling device for an internal combustion engine according to Item 2.   In a cooling method for an internal combustion engine in which the discharge amount of a variable coolant pump provided in the cooling device for the internal combustion engine can be changed according to the operation state of the internal combustion engine even at the same engine speed, the idle operation state, the deceleration operation state, and the acceleration A cooling method for an internal combustion engine, wherein the operation of the variable cooling water pump is controlled separately for an operation state and a normal operation state other than the operation state. Increase and decrease the discharge amount of the variable cooling water pump to control,
In the normal operation state, when the measured temperature of the temperature sensor for detecting the overheat state of the internal combustion engine is equal to or lower than the first determination temperature set in advance, the variable cooling water pump is set to the first operation state,
When the measured temperature exceeds the first determination temperature, performing a control during normal operation to increase the discharge amount of the variable cooling water pump from the first operation state,
In the idle operation state, when the measured temperature is equal to or lower than a second determination temperature set higher than the first determination temperature in advance, the variable cooling water pump is set to the first operation state, and the measured temperature is When the second determination temperature is exceeded, the discharge amount of the variable cooling water pump is increased from the first operating state,
In the deceleration operation state, when there is fuel injection, the variable cooling water pump is set to the first operation state, and when fuel injection is not performed, the discharge amount of the variable cooling water pump is set to the first operation state. More than
In the accelerated operation state, when the measured temperature is equal to or lower than a preset third determination temperature, the variable cooling water pump is set to the first operation state, and the measured temperature exceeds the third determination temperature. 5. The cooling method for an internal combustion engine according to claim 4, wherein the discharge amount of the variable cooling water pump is increased in comparison with the first operating state.   The discharge amount of the variable cooling water pump is increased or decreased by turning on and off the variable cooling water pump, and the operation state of the variable cooling water pump is turned off in the first operation state. Item 6. The cooling method for an internal combustion engine according to Item 5.

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