JP4730316B2 - Cooling device for internal combustion engine - Google Patents

Description

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

As one of the cooling devices for the internal combustion engine, a refrigerant for cooling the internal combustion engine, a first pump for circulating the refrigerant, and a second pump for assisting the first pump, the first pump is abnormal. First pump abnormality determining means for determining whether or not, and second pump operating means for circulating the refrigerant by operating the second pump when it is determined that the first pump is abnormal. In some cases, even when an abnormality occurs in the first pump, the internal combustion engine is cooled by the operation of the second pump, so that the vehicle to which the internal combustion engine is applied can be self-run. Is described in Patent Document 1 below.
JP 2001-165022 A

  In such a cooling apparatus for an internal combustion engine, in general, the second pump often does not operate for a long period of time. In this case, there is a problem that a phenomenon that the movable part such as the impeller of the second pump becomes hard and does not move (hereinafter, this phenomenon is referred to as “fixing”) occurs.

  Moreover, since the 2nd pump did not operate | move over a long period as mentioned above, there existed a problem that the 2nd pump was not utilized effectively. In addition, when an abnormality occurs in the first pump, the refrigerant circulation flow rate is often small when only the second pump is operated. In this case, since the internal combustion engine is difficult to be sufficiently cooled, there is a problem that the temperature of the internal combustion engine rises excessively.

  Accordingly, a first object of the present invention is to provide a cooling apparatus for an internal combustion engine of the above type that can suppress the occurrence of sticking of the second pump. A second object of the present invention is to provide a cooling device for an internal combustion engine of the above type in which the second pump can be used effectively. In addition, a third object of the present invention is to provide a cooling device for an internal combustion engine of the above type, in which the temperature of the internal combustion engine is maintained even when only the second pump is operated due to an abnormality in the first pump. It is providing the thing which can suppress rising too much.

  When it is determined that the refrigerant, the first pump, the second pump, the first pump abnormality determining unit, and the first pump are abnormal, the cooling device according to the present invention includes the second And a second pump operating means for circulating the refrigerant by operating the pump.

  Here, the “second pump” is used for the circulation of the refrigerant, for example, when it is determined that the first pump is abnormal, and in other cases (that is, the first pump is operating normally). ), It may be a pump that is not used for other purposes.

  In addition, the state where the “first pump is abnormal” is, for example, when the first pump is an electric power type pump, when the wiring of the electrical system of the pump is disconnected or short-circuited, or when the pump itself is broken. When the first pump is a mechanically powered pump, there are a state where the drive transmission system of the pump is broken, a state where the pump itself is broken, and the like.

  The first cooling device according to the present invention is characterized in that the second pump is operated for a predetermined period after the start of the internal combustion engine. According to this, generation | occurrence | production of adhering of the 2nd pump by not operating for a long period can be suppressed.

  The second cooling device according to the present invention includes the same refrigerant, a first pump, a second pump, a first pump abnormality determining means, and a second pump operating means as those provided in the first cooling device. I have.

  The second cooling device according to the present invention is characterized in that the current operating state of the internal combustion engine is an operating state in which a future temperature of the refrigerant at a portion where the refrigerant flows out of the internal combustion engine is expected to rise excessively. A pump combined means for operating the second pump together with the operation of the first pump even when the first pump is not determined to be abnormal when the temperature rise operation state is There is.

  According to this, when the operation state of the internal combustion engine becomes the above-described temperature rise operation state, the circulation flow rate of the refrigerant is increased by operating the second pump without increasing the load of the first pump. Can do. Accordingly, it is possible to suppress an excessive increase in the temperature of the refrigerant (that is, the temperature of the internal combustion engine) at the portion where the refrigerant flows out from the internal combustion engine while reducing the load on the first pump. In addition, the second pump can be effectively used.

  Further, in the second cooling device according to the present invention, the pump combined means is in the temperature rising operation state, the operating speed of the internal combustion engine is larger than a predetermined value, and is sucked into the combustion chamber of the internal combustion engine. It is preferable that the air quantity to be used is configured to be larger than a predetermined value. According to this, it can be easily determined whether or not the current operating state of the internal combustion engine is the temperature rising operation state.

  A third cooling device according to the present invention includes the same refrigerant as that provided in the first and second cooling devices, a first pump, and first pump abnormality determining means, and assists the first pump. When it is determined that the third pump and the first pump are abnormal, the third pump is provided with third pump operating means for operating the third pump to circulate the refrigerant.

  Here, the “third pump” is used for refrigerant circulation, for example, when it is determined that the second pump or the first pump described above is abnormal, and in other cases (that is, When the first pump is operating normally), the pump may be used other than the circulation of the refrigerant.

  The third cooling device according to the present invention is characterized by a heat exchanger that suppresses the generation of heat of the internal combustion engine or cools the refrigerant when the first pump is determined to be abnormal. The present invention is provided with heat generation suppression means for increasing the degree of cooling of the refrigerant. According to this, even when the circulating flow rate of the refrigerant is small, it is possible to suppress an excessive increase in the temperature of the internal combustion engine. In other words, a small capacity pump can be used as the second pump, and the range of selection of a pump used as an auxiliary to the first pump can be expanded.

  Specifically, for example, when the heat generation suppression unit determines that the first pump is abnormal, the internal combustion engine is prohibited from exceeding a predetermined value by opening the throttle valve of the internal combustion engine. You may be comprised so that generation | occurrence | production of the heat of an engine may be suppressed. In general, the amount of fuel injection in the internal combustion engine (and hence the amount of heat generated by the combustion of the fuel) is often controlled to increase as the throttle valve opening increases. Therefore, in this case, according to the above configuration, heat generation of the internal combustion engine can be easily suppressed.

  Further, for example, when the heat generation suppression means determines that the first pump is abnormal, the internal combustion engine is prevented from generating heat by prohibiting the operating speed of the internal combustion engine from exceeding a predetermined value. It may be configured to suppress. As the operating speed of the internal combustion engine increases, the amount of heat generated from the sliding part of the moving parts of the internal combustion engine increases, and the amount of heat generated by the entire internal combustion engine also increases.

  Therefore, even with the above configuration, the generation of heat in the internal combustion engine can be suppressed. In the case where the heat generation suppressing unit is configured as described above, for example, when it is determined that the first pump is abnormal, for example, a shift that is interposed in a driving system of a vehicle to which the driving force of the internal combustion engine is transmitted. By shifting the reduction ratio of the machine in a small direction (to the speed increasing side), even if the speed of the vehicle to which the internal combustion engine is applied is constant, the operation speed of the internal combustion engine can be easily reduced. According to this, it is easy to prohibit the operating speed of the internal combustion engine from exceeding a predetermined value.

  In addition, for example, when the heat generation suppression unit determines that the first pump is abnormal, the heat exchanger increases the operation speed of a blower that blows air toward the heat exchanger. The cooling degree of the refrigerant may be increased, and when it is determined that the first pump is abnormal, the operation of the blower is permitted, and the refrigerant flows out of the internal combustion engine. By lowering the lower limit value of the temperature range (that is, the temperature of the internal combustion engine) in the portion, the degree to which the refrigerant is cooled by the heat exchanger may be increased.

  Further, for example, when the heat generation suppression unit determines that the first pump is abnormal, the air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine is set to an air-fuel ratio richer than the stoichiometric air-fuel ratio, or By controlling the air-fuel ratio to be leaner than the stoichiometric air-fuel ratio, the internal combustion engine may be configured to suppress heat generation. When an air-fuel mixture richer than the stoichiometric air-fuel ratio is supplied to the internal combustion engine, when the air-fuel mixture burns, excess fuel cools the internal combustion engine. On the other hand, when an air / fuel mixture leaner than the stoichiometric air / fuel ratio is supplied to the internal combustion engine, the excess air cools the internal combustion engine when the air / fuel mixture burns. Therefore, even with the above configuration, the generation of heat in the internal combustion engine can be suppressed.

  In addition, for example, when the heat generation suppression unit determines that the first pump is abnormal, it prohibits the speed of the vehicle to which the internal combustion engine is applied from exceeding a predetermined value. You may be comprised so that generation | occurrence | production of a heat | fever may be suppressed. In general, the speed of the vehicle increases as the fuel injection amount in the internal combustion engine increases. Therefore, the amount of heat generated from the internal combustion engine increases as the vehicle speed increases.

  Therefore, even with the above configuration, the generation of heat in the internal combustion engine can be suppressed. In the case where the heat generation suppression unit is configured as described above, when it is determined that the first pump is abnormal, for example, the throttle valve opening of the internal combustion engine is reduced (that is, the fuel in the internal combustion engine). The vehicle speed can be easily prohibited from exceeding a predetermined value by automatically applying a braking force independently of the braking operation by the vehicle driver. .

  In the third cooling device according to the present invention, the vehicle is driven by the driving force of the internal combustion engine and the driving force of the electric motor, and the ratio of the driving force of the internal combustion engine to the driving force of the electric motor. Means for determining a driving force ratio according to the state of the vehicle, wherein the cooling device for the internal combustion engine comprises slope judgment means for judging whether or not the road on which the vehicle travels is a downhill, and the heat generation Preferably, the suppression unit is configured to cancel the prohibition when it is determined that the first pump is abnormal and the road determination unit determines that the road is a downhill. It is.

  When the vehicle travels on a downhill, the fuel injection in the internal combustion engine is often controlled to stop, and no heat is generated by the combustion of the fuel, so the amount of heat generated from the internal combustion engine is small. Therefore, in this case, even when it is determined that the first pump is abnormal, the necessity of prohibiting the vehicle speed from exceeding a predetermined value is small.

  Further, when a vehicle (for example, a hybrid vehicle) having the above configuration travels on a downhill, the electric power generated by the regenerative drive increases as the vehicle speed increases. Therefore, in this case, even when it is determined that the first pump is abnormal, it is preferable that the prohibition of the vehicle speed from exceeding a predetermined value is canceled.

  The above configuration is based on such knowledge. Thereby, it is suppressed that the vehicle speed is unnecessarily prohibited from exceeding the predetermined value, and regenerative driving is performed as compared with the configuration in which the vehicle speed is prohibited from exceeding the predetermined value even on the downhill. The generated power can be increased. Therefore, the battery can be charged efficiently.

  As described above, when the heat generation suppression unit determines that the first pump is abnormal and the slope determination unit determines that the road is a downhill, the prohibition is canceled, and It is preferable to shift the reduction ratio of the transmission provided in the drive system of the vehicle to which the driving force of the internal combustion engine is transmitted in a large direction (to the deceleration side). Thereby, the electric power generated by the regenerative drive can be further increased. Therefore, the battery can be charged more efficiently.

  In the third cooling device according to the present invention, the vehicle to which the internal combustion engine is applied is driven by the driving force of the internal combustion engine and the driving force of the electric motor. Means for determining a driving force ratio, which is a ratio to the driving force, according to the state of the vehicle, and when the heat generation suppressing means determines that the first pump is abnormal, the stored amount of the battery is a predetermined value; It is preferable that the driving force ratio is set to “0” until the following is satisfied, so that generation of heat of the internal combustion engine is suppressed. Thus, only the electric motor is driven by the electric power stored in the battery without burning the fuel in the internal combustion engine, so that the amount of heat generated from the internal combustion engine can be maintained at a minute value.

  Hereinafter, embodiments of a cooling apparatus for an internal combustion engine according to the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a schematic configuration of a system in which a cooling device according to a first embodiment of the present invention is applied to a spark ignition type multi-cylinder (four-cylinder) internal combustion engine 10. The cooling device includes a cooling water cooling unit 20 that cools cooling water (the refrigerant) that cools the internal combustion engine 10 and includes a water cooling jacket formed on a side surface of a combustion chamber of a cylinder block portion of the internal combustion engine 10. A cooling water passage inside the engine 10, a radiator (the heat exchanger) 21 provided in the cooling water cooling unit 20, an outlet of the cooling water inside the cooling water passage inside the internal combustion engine 10, A radiator upper hose h1 that connects the coolant, and a radiator lower hose h2 that connects the coolant outlet of the radiator 21 and the coolant inlet of the coolant channel inside the internal combustion engine 10, and An electrically driven first pump 30 that is disposed at a predetermined position of the radiator lower hose h2 and circulates the cooling water in the first cooling water circulation passage, and the cooling of the radiator 21 The first connecting portion c1 which is a predetermined position of the radiator lower hose h2 between the water outlet and the cooling water inlet of the first pump 30, the cooling water outlet of the first pump 30, and the cooling water flow inside the internal combustion engine 10 A predetermined position of the bypass hose h3 that connects the second connecting portion c2 that is a predetermined position of the radiator lower hose h2 between the inlet of the cooling water of the road and the first disposed as described later on the bypass hose h3. An electrically driven second pump 40 that assists the pump 30 is provided.

  The internal combustion engine 10 includes an intake pipe 11 including an intake manifold that forms an intake passage communicating with a combustion chamber of a cylinder block portion, a throttle valve 12 in the intake pipe 11 and having a variable opening cross-sectional area of the intake passage, An exhaust pipe including an actuator 13 for the throttle valve 12, four injectors 14 for injecting fuel into the intake pipe 11 corresponding to the four combustion chambers, and an exhaust manifold that forms an exhaust passage communicating with the combustion chamber of the cylinder block portion 15.

  The opening degree TA of the throttle valve 12 is controlled by an electric control device 60 (described later) so as to increase as the accelerator operation amount of the driver of the vehicle increases when the first pump 30 operates normally. ing. The fuel injection amount instructed to the injector 14 is estimated by a well-known method based on the opening degree TA of the throttle valve 12 and the operating speed NE of the internal combustion engine 10 detected by a crank position sensor 52 described later. Is determined so as to increase as the in-cylinder intake air amount Mc that is the amount of fresh air sucked into the cylinder increases, and based on the air-fuel ratio of the exhaust detected by an air-fuel ratio sensor 53 described later, When the first pump 30 operates normally, the electric control device 60 controls the air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine 10 to be the stoichiometric air-fuel ratio.

  The cooling water cooling unit 20 further includes an electrically driven blower 22 that blows air toward the radiator 21. The blower 22 is rotationally driven by an electric motor 23, and the number of rotations thereof is variable. When the first pump 30 operates normally, the electric motor 23 of the blower 22 has a predetermined number of revolutions when a cooling water temperature THW detected by a cooling water temperature sensor described later becomes equal to or higher than a predetermined second temperature THW2. It is controlled by the electric control device 60 so that the rotation drive is started.

  The 1st pump 30 and the 2nd pump 40 are rotationally driven by the electric motor 31 and the electric motor 41, and the rotation speed is variable. When the first pump 30 operates normally, the electric motor 31 of the first pump 30 starts rotating when the cooling water temperature THW is equal to or higher than a predetermined first temperature THW1 (<the second temperature THW2). As described above, the electric control device 60 is controlled. In this case, the number of revolutions of the electric motor 31 is controlled to increase as the cooling water temperature THW increases, the in-cylinder intake air amount Mc increases, and the operating speed NE increases. Thereby, in this case, the temperature of the internal combustion engine 10 becomes excessive because the cooling water circulates in the first cooling water circulation passage along the direction of the solid arrow shown in FIG. 1 at a flow rate corresponding to the cooling water temperature THW. The internal combustion engine 10 is cooled so as not to rise. The operation of the second pump 40 will be described with reference to the flowchart shown in FIG.

  In addition, the cooling device includes a cooling water temperature sensor 51 disposed at a connection portion of the radiator upper hose h1 with the cooling water outlet of the cooling water passage inside the internal combustion engine 10, and the cooling water is supplied from the cooling water outlet to the cooling water. The coolant temperature THW in the portion where the engine flows out is detected, and is further disposed in the exhaust pipe 15 and the crank position sensor 52 that is disposed at a predetermined position of the internal combustion engine 10 and detects the operating speed NE. An air-fuel ratio sensor 53 for detecting the air-fuel ratio of the exhaust gas.

  The cooling device further includes an electric control device 60, and signals from the sensors 51 to 53 are transmitted to the CPU of the electric control device 60. The CPU includes the actuator 13 of the throttle valve 12, the injector 14, and the blower. 22, drive signals are sent to the electric motors 23, 31, and 41 of the first pump 30 and the second pump 40.

  Hereinafter, the operation of the cooling device according to the first embodiment of the present invention will be described with reference to the routine for instructing the operation of the second pump 40 executed by the CPU of the electric control device 60 shown in the flowchart of FIG. .

  The CPU starts processing from step 200 and proceeds to step 205 to determine whether or not the internal combustion engine 10 has just been started. If the internal combustion engine 10 has just started, it determines “Yes” and proceeds to step 210. Proceed to instruct the electric motor 41 to operate the second pump 40 for a predetermined period.

  Thus, every time the internal combustion engine 10 is started, the second pump 40 is operated for a predetermined period immediately after the internal combustion engine 10 is started. As a result, a phenomenon that the movable part such as the impeller of the second pump 40 becomes hard and does not move due to the second pump 40 not operating for a long period of time (hereinafter, this phenomenon is referred to as “fixing”) occurs. This can be suppressed.

  On the other hand, if the internal combustion engine 10 is not immediately after starting, the CPU makes a “No” determination at step 205 to proceed to step 215 to determine whether or not the first pump 30 is abnormal. As this determination method, the flow rate of the cooling water circulating through the first cooling water circulation passage is “0” or is abnormally small, so that the cooling water temperature THW becomes a predetermined third temperature THW3 (> the second temperature THW2, For example, if the electrical system wiring of the first pump 30 is disconnected or short-circuited even if the cooling water temperature THW is lower than the third temperature THW3, the pump abnormal condition is satisfied. The first pump 30 is determined to be abnormal. This step 215 corresponds to a part of the first pump abnormality determining means.

  Here, the operation instruction of the first pump 30 will be described. Unless the CPU determines that the first pump 30 is abnormal, as described above, the electric motor 31 is driven to rotate according to the cooling water temperature THW or the like. By giving the instruction, the cooling water circulates through the first cooling water circulation passage. On the other hand, if it is determined that the first pump 30 is abnormal, the first pump 30 is stopped. 30 electric motors 31 are instructed.

  Returning to the description of the operation instruction of the second pump 40, when the pump abnormal condition is satisfied, the CPU makes a “Yes” determination at step 215 to proceed to step 220 to operate the second pump 40. After instructing the electric motor 41, the process proceeds to step 295, and this routine is temporarily terminated. Thereby, instead of circulating the cooling water through the first cooling water circulation passage (see the solid line arrow in FIG. 1), the cooling water is supplied from the first connection portion c1 of the radiator lower hose h2 of the first cooling water circulation passage. A second cooling water circulation passage, which is a cooling water passage in which a portion up to the second connection portion c2 is replaced by a bypass hose h3, is circulated along the direction of the broken arrow in FIG.

  Therefore, even when it is determined that the first pump 30 is abnormal and the first pump 30 is stopped, the second pump 40 is activated, so that the first pump 30 is normally operated. The internal combustion engine 10 can be cooled by cooling water. This step 220 corresponds to a part of the second pump actuating means.

  On the other hand, if the pump abnormal condition is not satisfied, the CPU makes a “No” determination at step 215 to proceed to step 225 where the current in-cylinder intake air amount Mc is greater than a predetermined value Mc1 and the current It is determined whether or not the operating speed NE is greater than a predetermined first operating speed NE1. When the current in-cylinder intake air amount Mc and the current operating speed NE are larger than these values Mc1 and the first operating speed NE1, the coolant temperature THW (that is, the temperature of the internal combustion engine 10) will be in the future. It is a value that is expected to rise excessively, and is determined by a table that has been adapted and prepared in advance through experiments or the like. That is, a state in which the current in-cylinder intake air amount Mc is larger than the value Mc1 and the current operation speed NE is greater than the first operation speed NE1 corresponds to the temperature increase operation state.

  When the current in-cylinder intake air amount Mc and the current operation speed NE are in the relationship of “Mc> Mc1 and NE> NE1”, the CPU makes a “Yes” determination at step 225 to proceed to step 230. After proceeding and instructing the electric motor 41 to operate the second pump 40, the routine proceeds to step 295 and this routine is temporarily terminated. In this case, since it is not determined that the first pump 30 is abnormal, the first pump 30 is instructed to continue to operate.

  As a result, when the second pump 40 is operated along with the operation of the first pump 30, the cooling water circulating in the first cooling water circulation passage passes through the bypass hose h3 in addition to the first cooling water circulation passage. To come. That is, the cooling water circulates in both the directions of the solid arrow and the broken arrow in FIG. 1 through the passage formed by the first cooling water circulation passage and the bypass hose h3.

  As a result, the flow rate of the cooling water passing through the cooling water flow path inside the internal combustion engine 10 is increased by an amount corresponding to the operation of the second pump 40, so that the operation state of the internal combustion engine 10 is the above-described temperature rise operation state. Even if it exists, it can suppress that the cooling water temperature THW (namely, temperature of the internal combustion engine 10) rises too much. Further, when the flow rate of the cooling water is increased, the load on the first pump 30 can be reduced. In addition, even if it is not determined that the first pump 30 is abnormal, the second pump 40 operates, so the second pump 40 can be used effectively. These steps 225 and 230 correspond to a part of the pump combination means.

  On the other hand, if the current in-cylinder intake air amount Mc and the current operating speed NE are not in the relationship of “Mc> Mc1 and NE> NE1”, the CPU makes a “No” determination at step 225 to step After proceeding to 235 and instructing the electric motor 41 to stop the second pump 40, the routine proceeds to step 295 and this routine is temporarily terminated. As a result, the cooling water circulates through the first cooling water circulation passage.

  As described above, according to the first embodiment of the cooling apparatus for an internal combustion engine according to the present invention, when it is determined that the first pump 30 for circulating the cooling water for cooling the internal combustion engine 10 is abnormal, In the cooling device for the internal combustion engine 10 that assists the first pump 30 by operating the two pumps 40 and circulating the cooling water, the second pump 40 is operated for a predetermined period immediately after the start of the internal combustion engine 10. Thereby, it can be suppressed that the second pump 40 is stuck due to the second pump 40 not operating for a long period of time.

  Even if it is not determined that the first pump 30 is abnormal, the current in-cylinder intake air amount Mc and the current operating speed NE are based on the value Mc1 and the first operating speed NE1. When each is in a large state, that is, when the current operation state is an operation state in which the coolant temperature THW (that is, the temperature of the internal combustion engine 10) is expected to increase excessively in the future, along with the operation of the first pump 30, The second pump 40 is activated.

  As a result, an excessive increase in the coolant temperature THW can be suppressed by increasing the flow rate of the coolant passing through the coolant flow path inside the internal combustion engine 10 by an amount corresponding to the operation of the second pump 40. Further, when the flow rate of the cooling water is increased, the load on the first pump 30 can be reduced. In addition, even if it is not determined that the first pump 30 is abnormal, the second pump 40 can be used effectively because the second pump 40 operates.

  The present invention is not limited to the first embodiment, and various modifications can be employed within the scope of the present invention. For example, in the first embodiment, the second pump 40 is operated for a predetermined period immediately after the start of the internal combustion engine 10, but instead, a predetermined period has elapsed since the start of the internal combustion engine 10. The operation of the second pump 40 may be started later, and the second pump may be operated for a predetermined period.

(Second Embodiment)
Next, a cooling device for an internal combustion engine according to a second embodiment of the present invention will be described. In the second embodiment, as the pump for assisting the first pump 30, when the first pump 30 is operating normally, the pump used for purposes other than the circulation of the cooling water is used. When it is determined that the pump 30 is abnormal, it is different from the first embodiment in that control is performed to suppress the heat generation of the internal combustion engine 10 and increase the degree of cooling of the cooling water.

  Hereinafter, only such a difference will be described with reference to FIG. 3 which is a schematic configuration diagram of a system in which the cooling device according to the second embodiment of the present invention is applied to the internal combustion engine 10 of the first embodiment. 3, the same members and parts as those shown in FIG. 1 described above and parts, or equivalent members and parts, are denoted by the same reference numerals as those shown in FIG.

  The cooling device includes an electrically driven third pump 70 that is rotationally driven by an electric motor 71 at a position where the second pump 40 provided in the first embodiment is disposed, a first connection portion c1, and a third pump. At a predetermined position of the bypass hose h3 between the outlet of the third pump 70 and the second connection part c2 disposed at a predetermined position of the bypass hose h3 between the inlet of the 70. The second switching valve v2 is provided, and the electric control device 60 can switch the flow path in the directions indicated by the arrows A and B in FIG. As the third pump 70, a pump having a smaller capacity than the first pump 30 is used.

  The first switching valve v1 and the second switching valve v2 are instructed to switch the flow path in the direction indicated by the arrow A when the first pump 30 operates normally. Thereby, the window washer passage which is a passage formed by the first window washer hose h4, the bypass hose h3, and the second window washer hose h5 is communicated, and the operation of the third pump 70 according to the operation of the vehicle driver is performed. As a result, as shown by the one-dot chain line arrow in FIG. 3, the window washer fluid is allowed to be pumped from the window washer fluid tank 80 included in the vehicle to which the internal combustion engine 10 is applied to a window washer nozzle (not shown). ing. At the same time, the passage of cooling water through the bypass hose h3 is regulated. Accordingly, in this case, the operation of the first pump 30 causes the cooling water to circulate in the first cooling water circulation passage along the direction of the solid arrow in FIG.

  On the other hand, the first switching valve v1 and the second switching valve v2 are instructed to switch the flow path in the direction indicated by the arrow B when the first pump 30 is abnormal. Thereby, the passage of the window washer liquid in the window washer passage is restricted. At the same time, the passage of the cooling water through the bypass hose h3 is permitted, and the second cooling water circulation passage is formed as in the first embodiment. Therefore, in this case, instead of the operation of the first pump 30, the operation of the third pump 70 causes the cooling water to circulate in the second cooling water circulation passage along the direction of the broken arrow in FIG. ing. That is, in this case, the third pump 70 operates in the same manner as the second pump 40 provided in the first embodiment. As described above, since the capacity of the third pump 70 is smaller than the capacity of the first pump 30, the flow rate of the cooling water circulating through the second cooling water circulation passage is the same as that of the first cooling water circulation passage. Small compared to circulating coolant flow rate.

  As described above, the third pump 70 is used for pumping the window washer fluid when the first pump 30 is operating normally (see the one-dot chain line arrow in FIG. 3), while the first pump When it is determined that the engine 30 is abnormal, the cooling water is circulated in the second cooling water circulation passage to cool the internal combustion engine 10 so as to assist the first pump 30 instead of pumping the window washer fluid. (See the dashed arrow in FIG. 3).

  In addition to the routine equivalent to the routine shown in FIG. 2 described above, the CPU of the electric control device 60 executes a heat generation suppression / cooling water cooling control routine of the internal combustion engine 10 shown in the flowchart of FIG. Yes. Hereinafter, the operation unique to the cooling device according to the second embodiment of the present invention will be described with reference to the routine shown in FIG. 4 unique to the second embodiment.

  The CPU starts the process from step 400 and proceeds to step 405 to determine whether or not the first pump 30 is abnormal. If the pump abnormal condition is not satisfied, the CPU determines “No” and immediately proceeds to step 495. Proceed to end this routine once. The determination method in step 405 is the same as the determination method of whether or not the first pump 30 in the first embodiment is abnormal. Thus, as described above, the cooling water circulates in the first cooling water circulation passage by the operation of the first pump 30 to cool the internal combustion engine 10 (see the solid line arrow in FIG. 3). In this case, the control for suppressing the generation of heat of the internal combustion engine 10 and the control for increasing the degree of cooling the cooling water by the radiator 21 are not executed.

  On the other hand, if the pump abnormal condition is satisfied, the CPU makes a “Yes” determination at step 405 to proceed to step 410 where the throttle valve 12 is opened so that the upper limit of the opening degree TA becomes a predetermined value TA1. An instruction is given to the actuator 13 of the valve 12. Thereby, even when the accelerator operation amount of the driver of the vehicle is excessively large, the opening degree of the throttle valve 12 is prohibited from exceeding the value TA1, and the injector 14 determined as described above is instructed. An excessively large fuel injection amount is also prohibited. Therefore, heat generation of the internal combustion engine 10 can be suppressed.

  Next, the CPU proceeds to step 415 to set the second temperature THW2 to a lower temperature than when the first pump 30 is operating normally. Thereby, even if the cooling water temperature THW is relatively low, the operation of the blower 22 is started, so that the degree of cooling of the cooling water by the radiator 21 can be increased. The cooling control of the cooling water in step 415 is particularly effective when it is determined that the first pump 30 is abnormal because the wiring of the electrical system of the first pump 30 is disconnected or short-circuited.

  Next, the CPU proceeds to step 420 to instruct the electric motor 23 of the blower 22 so that the rotation speed of the blower 22 becomes larger than the predetermined rotation speed and becomes higher as the cooling water temperature THW is higher. Thereby, the grade which cools cooling water with the radiator 21 can be enlarged.

  Subsequently, the CPU proceeds to step 425 to determine the fuel injection amount instructed to the injector 14 so that the air-fuel ratio of the air-fuel mixture supplied to the internal combustion engine 10 is leaner than the stoichiometric air-fuel ratio. . As a result, the internal combustion engine 10 is cooled by excess air that is not used for combustion in the combustion chamber of the internal combustion engine 10. Therefore, heat generation of the internal combustion engine 10 can be suppressed.

  Next, the CPU proceeds to step 430, where the vehicle to which the internal combustion engine 10 is applied is provided and the automatic transmission is performed so that the reduction ratio of the automatic transmission (not shown) independent of the operation of the driver of the vehicle becomes a smaller value. Instruct the machine actuator. Thereby, even if the speed of the vehicle is constant, the operating speed NE of the internal combustion engine 10 can be easily reduced, and the upper limit of the operating speed NE of the internal combustion engine 10 is a predetermined second operating speed NE2 (for example, 1500 rpm). ) Can be easily forbidden. Accordingly, the amount of heat generated from the sliding portion of the movable part of the internal combustion engine 10 is reduced, and the amount of heat generated by the internal combustion engine 10 as a whole is also reduced, so that the generation of heat of the internal combustion engine 10 can be suppressed.

  Next, the CPU proceeds to step 435, where the vehicle to which the internal combustion engine 10 is applied is provided and braking is applied by an automatic braking mechanism (not shown) independent of the operation of the driver of the vehicle, so that the upper limit of the vehicle speed is increased. After instructing the automatic braking mechanism to reach a predetermined value (for example, 40 km / h), the routine proceeds to step 495 and this routine is temporarily terminated. Thereby, it can be prohibited that the speed of the vehicle exceeds the predetermined value, and the generation of heat of the internal combustion engine 10 accompanying the increase in the speed of the vehicle can be suppressed.

  When the pump abnormal condition is satisfied, as described above, instead of the third pump 70 pumping the window washer liquid (see the arrow of the dashed line in FIG. 3), the cooling water is supplied to the second cooling. By circulating through the water circulation passage, the internal combustion engine 10 is cooled (see the broken arrow in FIG. 3). In addition, as described above, the execution of the routine processes of steps 410 to 435 by the CPU of the electric control device 60 suppresses the generation of heat of the internal combustion engine 10 and the degree of cooling of the cooling water by the radiator 21. Increased. The routine shown in FIG. 4 corresponds to a part of the heat generation suppressing means.

  As described above, according to the second embodiment of the cooling apparatus for an internal combustion engine according to the present invention, when it is determined that the first pump 30 that circulates the cooling water for cooling the internal combustion engine 10 is abnormal, The cooling device for the internal combustion engine 10 that assists the first pump 30 by operating the third pump 70 used to pump the window washer fluid and circulating the cooling water when the one pump 30 is operating normally. When it is determined that the first pump 30 is abnormal, the generation of heat of the internal combustion engine 10 is suppressed, and the cooling degree of the cooling water is increased by the radiator 21.

  As described above, since the capacity of the third pump 70 is smaller than the capacity of the first pump 30, the flow rate of the cooling water circulating in the second cooling water circulation passage is small, and the internal combustion engine 10 is sufficiently operated. Difficult to cool. Here, as described above, the generation of heat of the internal combustion engine 10 is suppressed, and the degree of cooling of the cooling water is increased by the radiator 21, so that the capacity of the third pump 70 is small. The temperature of the internal combustion engine 10 can be suppressed from rising excessively. In other words, a small pump can be used as the third pump 70, and the range of selection of a pump used as an auxiliary to the first pump 30 can be expanded.

  The present invention is not limited to the second embodiment, and various modifications can be adopted within the scope of the present invention. For example, in the second embodiment, when the first pump 30 operates normally, the third pump 70 is configured to operate as a pump used for pumping the window washer fluid. Thus, for example, when the vehicle to which the internal combustion engine 10 is applied is a hybrid vehicle or the like, when the first pump 30 operates normally, the third pump 70 is used for circulation of cooling water for heating the vehicle interior. You may be comprised so that it may operate | move as a pump, and you may be comprised so that it may operate | move as a pump used for the circulation of the cooling water for cooling an inverter.

  Moreover, in the said 2nd Embodiment, when it determines with the 1st pump 30 being abnormal, it is controlled so that the upper limit of the speed of the vehicle to which the internal combustion engine 10 is applied becomes a predetermined value. However, if the vehicle is a hybrid vehicle or the like and it is determined by a known determination means that the road on which the vehicle is traveling is a downhill, the processing of step 435 of the routine shown in FIG. 4 is performed. It may be configured to be omitted. As a result, when the road on which the vehicle is traveling is a downhill, the vehicle speed can be increased by releasing the prohibition of the vehicle speed from exceeding the predetermined value, and the electric power generated by the regenerative drive Can be enlarged. As a result, the battery can be charged efficiently.

  In addition, in the second embodiment, when the vehicle to which the internal combustion engine 10 is applied is a hybrid vehicle or the like, and it is determined that the first pump 30 is abnormal, the driving force of the internal combustion engine 10 May be configured so that the electric motor is driven until the charged amount of the battery becomes a predetermined value or less. Thus, only the electric motor is driven by the electric power stored in the battery without burning the fuel in the internal combustion engine, so that the amount of heat generated from the internal combustion engine can be maintained at a minute value.

1 is a schematic view of a system in which a cooling device according to a first embodiment of the present invention is applied to an internal combustion engine. It is the flowchart which showed the routine for performing the operation | movement instruction | indication of the 2nd pump which CPU of the electric control apparatus shown in FIG. 1 performs. It is the schematic of the system which applied the cooling device concerning 2nd Embodiment of this invention to the internal combustion engine. 3 is a flowchart showing a routine for performing heat generation suppression and cooling water cooling control of the internal combustion engine executed by a CPU of the electric control device shown in FIG. 2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 12 ... Throttle valve, 20 ... Cooling water cooling part, 21 ... Radiator, 22 ... Blower, 30 ... 1st pump, 40 ... 2nd pump, 60 ... Electric control apparatus, 70 ... 3rd pump.

Claims (1)

A refrigerant for cooling the internal combustion engine;
A first pump for circulating the refrigerant;
A second pump that is not used for any other purpose than assisting the first pump and circulating the refrigerant ;
With
First pump abnormality determining means for determining whether or not the first pump is abnormal;
The second pump is stopped while it is determined that the first pump is normal, and the second pump is operated based on the determination that the first pump is abnormal. Second pump operating means for circulating the refrigerant;
An internal combustion engine cooling device comprising:
The second pump operating means includes
Regardless of whether or not the first pump is determined to be abnormal based on the start of the internal combustion engine, an internal combustion engine that operates the second pump for a predetermined period after the start of the internal combustion engine is started. Cooling system.

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