JP4771969B2 - Cooling control device - Google Patents

Description

  The present invention relates to a technical field of a cooling control device that controls a cooling device that cools, for example, an internal combustion engine or the like with cooling water.

  As this type of device, a device for reducing unnecessary pump work has been proposed (for example, see Patent Document 1). According to the cooling apparatus for a liquid-cooled internal combustion engine disclosed in Patent Document 1 (hereinafter referred to as “prior art”), a target in which the discharge flow rate of the pump is determined based on the rotational speed and load of the internal combustion engine. By controlling the discharge flow rate, for example, as the engine load decreases, the discharge flow rate can be reduced, and unnecessary pump work can be reduced.

  In addition, the technique which performs the rotational speed control of an electric water pump and the valve opening control of a flow control valve according to the driving | running state is also proposed (for example, refer patent document 2).

  In addition, a technique for intermittently operating an electric water pump when the water temperature is equal to or lower than a predetermined value has been proposed (see, for example, Patent Document 3).

JP 2000-45774 A JP 2005-36729 A JP 2006-214281 A

  In the case of injecting cooling water in the prior art, for example, it is possible to increase water injection by setting a large target discharge amount, but on the other hand, the cooling water cannot be supplied to a pump bearing or the like. Air biting may occur, causing problems such as seizure in the pump or the internal combustion engine in addition to the pump. That is, the conventional technique has a technical problem that it is difficult to safely inject cooling water in some cases.

  This invention is made | formed in view of the problem mentioned above, and makes it a subject to provide the cooling control apparatus which can protect an electric pump at the time of water injection of cooling water.

In order to solve the above-described problem, a cooling control device according to the present invention includes an electric pump, and the electric pump can cool the cooled system by circulatingly supplying cooling water to the cooled system including the internal combustion engine. A cooling control device for controlling a cooling device, wherein target rotational speed determination means for determining a target rotational speed of the electric pump according to predetermined operating conditions in the internal combustion engine, and the rotational speed of the electric pump is the target rotational speed A first control means for controlling the electric pump so as to achieve a rotational speed; an actual rotational speed specifying means for specifying the actual rotational speed of the electric pump; and the target rotation when the cooling water is injected. And a second control means for controlling the electric pump so that the intermittent operation is performed when the deviation between the number and the actual rotational speed is equal to or greater than a predetermined allowable value .

  The “internal combustion engine” provided in the vehicle of the present invention has, for example, a plurality of cylinders, and an explosion that occurs when fuel such as gasoline, light oil or various alcohols burns in the combustion chambers of each of the plurality of cylinders. It is a concept that encompasses an engine that can output powerful power as power through an output shaft such as a crankshaft via a mechanical transmission path such as a piston and a connecting rod. Refers to the engine. The cooled system including the internal combustion engine is cooled by a cooling device.

  The “cooled system” is a concept that can appropriately include a part, mechanism, or device different from the internal combustion engine, for example, that generates heat during operation or is exposed to external heat radiation as long as the internal combustion engine is included. It is.

  In the present invention, the “cooling device” includes at least an electric pump that includes at least an electrically driven portion, and can take various forms such as a centrifugal type or a spiral type. Cooling water such as LLC (Long Life Coolant) is caused by, for example, physical, mechanical, mechanical, electrical or chemical action by the electric pump, for example, by rotation of a pump impeller that is driven to rotate by a motor or the like. It is a concept encompassing means capable of cooling the system to be cooled by circulating and supplying cooling water as working fluid.

  In the cooling apparatus defined by such a concept, for example, the electric pump is installed in a circulation path or the like that can take a physical form such as a water jacket stretched around a metal or resin cooling water pipe or a cylinder, The cooling water is circulated and supplied by discharging the cooling water to the circulation path. At this time, the system to be cooled is cooled mainly by heat exchange between the system to be cooled and the cooling water.

  According to the cooling control device of the present invention, at the time of operation, the target rotational speed that can take the form of various processing units such as an ECU (Electronic Control Unit), various controllers, various computer systems such as a microcomputer device, or the like. By the action of the determining means, the target rotational speed of the electric pump is determined according to predetermined operating conditions in the internal combustion engine such as the engine rotational speed and load.

  Here, “the number of revolutions” according to the present invention includes the number of revolutions itself, and as a preferred form, for example, the number of revolutions per unit time (that is, the rotational speed in other words) is associated with the concept of time. This is a concept that includes the rotation speed. The target rotational speed refers to a target value for controlling the rotational speed defined by such a concept. For example, the electric pump can be made experimentally, empirically, theoretically or based on simulations in advance. It is determined according to a map, an algorithm, a calculation formula, or the like set to be able to operate efficiently (for example, to save power resources as much as possible). That is, the target rotational speed can be calculated by selecting a value corresponding to the operating condition of the internal combustion engine at that time from such a map or the like, It is determined by performing a numerical operation.

  Note that the “rotation speed of the electric pump” means that in the electric pump, the circulating supply amount (for example, discharge amount) of the cooling water can be associated with the one-to-one, one-to-many, many-to-one, or many-to-many rotation. It refers to the rotational speed of the part, and preferably refers to the rotational speed of a motor that can function as a power source of the electric pump, or for example, a pump impeller that rotates with the rotation of the motor.

  When the target rotational speed is thus determined, the rotational speed of the electric pump is determined by the first control means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device. Physical, mechanical, mechanical or electrical drive of the appropriate drive means, for example as part of the electric pump or at least partly as a separate part from the electric pump The electric pump is controlled through control or the like.

  Here, in particular, when cooling water is poured, for example, when the cooling water is exchanged, from a circulation path including, for example, a reservoir tank, a radiator hose, a water jacket, various cooling water pipes, etc. As the cooling water is extracted, gas such as air is likely to be mixed or generated in the circulation path of the cooling water. On the other hand, an electric pump is often driven even during such water injection because of a request for suitably extracting cooling water from such a circulation path that easily adopts a physically complicated configuration.

  However, in an electric pump, air mixed or generated in this manner is less likely to be discharged than in cooling water, so that a rotational drive part in the electric pump or a part corresponding to the rotational drive part, for example, a bearing part in the above-described motor, etc. In addition, the air mixed or generated in this way stays, and a state called “air biting” tends to occur. In such a portion where the air is biting, there is a relative shortage of cooling water, which inevitably causes various problems due to excessive heat load such as seizure of the bearing portion. In particular, when the rotational speed of the electric pump is relatively increased in order to relatively improve the water injection related to water injection, such a problem can be remarkably caused.

  Therefore, the cooling control apparatus according to the present invention further has the following configuration in order to quickly and safely inject cooling water. That is, the cooling control device of the present invention is provided with an actual rotational speed specifying means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, and the actual rotational speed of the electric pump can be specified. Is done.

  Note that “specific” in the present invention refers to, for example, detecting directly or indirectly as a physical numerical value or an electrical signal or the like corresponding to a physical numerical value via some detection means, appropriate storage means, etc. Selecting a corresponding numerical value from a map or the like stored in the map, or estimating through such selection, a preset algorithm based on the detected physical numerical value or electrical signal or the selected or estimated numerical value It is a broad concept encompassing derivation or estimation according to a calculation formula or the like, or simply acquiring a value detected, selected, estimated or derived as an electric signal or the like. Within the scope of such a concept, the actual rotation speed specifying means obtains the actual rotation speed by acquiring an electrical signal or the like corresponding to the actual rotation speed from various sensors such as a rotation sensor attached to the electric pump. Identify.

On the other hand, the cooling control apparatus according to the present invention includes a second control means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, and the second control means includes: When cooling water is injected, the electric pump is controlled so that intermittent operation is performed when the deviation between the target rotational speed and the actual rotational speed is greater than or equal to a predetermined allowable value .

  The rotational speed of the electric pump is controlled by the first control means so as to reach the target rotational speed. However, when the air is caught, the viscous resistance of the air is smaller than the viscous resistance of the cooling water. As a result, the rotational speed of the electric pump tends to increase with respect to the target rotational speed. That is, the degree of air biting preferably has a one-to-one, one-to-many, many-to-one or many-to-many relationship with the degree of relative increase in the rotational speed of the electric pump.

  Therefore, the relative relationship between the target rotational speed and the actual rotational speed indicates whether or not a malfunction of the electric pump due to excessive rotation of the electric pump, in other words, due to excessive heat load has already occurred, or It can be an index for determining whether or not it will occur in the near future, or whether or not the electric pump is in a situation where some measures should be taken from the viewpoint of protecting the electric pump.

Here, the “relative relationship” according to the present invention refers to the rotational state of the electric pump from the viewpoint of heat load, for example, whether or not the electric pump is in an over-rotation state with at least sufficient accuracy in practice. a concept including the estimated may relationship, the cooling controller in accordance with the present invention particularly refers to a deviation between the actual rotational speed and the target speed.

  On the other hand, the intermittent operation performed based on such a relative relationship is, for example, according to the target rotational speed described above, according to another target rotational speed set separately from the target rotational speed, or particularly as the target value. Is not set, and at least a part of the normal operation period in which the electric pump is operated so that the rotation speed is set at a relatively random speed so that the cooling water can be circulated and supplied to a considerable extent is caused by over-rotation. Is a concept that encompasses an operation mode that is replaced with an operation period in which the electric pump is operated in a low-rotation region to an extent that does not proceed at least substantially, and as a preferred form, such a normal operation period and It refers to an operation mode in which the low-rotation operation period alternates. Further, as a preferable operation mode of the electric pump in the low rotation operation period, the electric pump may be stopped, or may be operated in a low rotation region such that the rotation speed can be regarded as substantially zero. Good.

By such intermittent operation, the heat load applied to the electric pump is relatively reduced, and the electric pump can be physically, mechanically, electrically, or chemically protected during water injection. Further, during the intermittent operation, the period of relatively high speed and the relatively low period of the electric pump is appropriately switched, so that the cooling water pulsation is likely to occur. Such pulsation makes it easier to eliminate the air biting of the electric pump than when no intermittent operation is performed. That is, according to the cooling control device of the present invention, the electric pump can be protected efficiently and effectively.
Here, in particular, in the cooling control device according to the present invention, the second control means performs the intermittent operation when the deviation between the actual rotational speed and the target rotational speed is equal to or greater than a predetermined allowable value. Control the electric pump.
The electric pump has a control amount that regulates the driving state of the electric pump based on, for example, experimentally, empirically, theoretically, or simulation in advance so that the target rotational speed is maintained by the first control unit. According to a map or the like that is associated with the rotational speed so as to ensure that there is no problem in practice, for example, the actual rotational speed specified by the actual rotational speed specifying means is fed back as appropriate. Control is performed while correcting or learning the amount. However, the actual rotational speed and the target rotational speed do not necessarily coincide with each other, and may be accompanied by a constant or indefinite deviation in terms of control. Further, the magnitude of this deviation can be correlated with the degree of air biting, but in the range where the deviation is relatively small, there is a possibility that the magnitude of the deviation will not cause a problem in the electric pump even if air biting occurs.
Therefore, when the deviation is equal to or larger than a tolerance that can be set as a deviation or the like that does not cause a malfunction of the electric pump in practice based on, for example, experimentally, empirically, theoretically, or simulation in advance. By performing the intermittent operation, a high benefit of protecting the electric pump while maintaining water injection is provided.

  In view of the fact that both the first control means and the second control means control the electric pump, the first control means and the second control means are physical, mechanical, or electrical. At least some of these configurations may be common to each other.

  In one aspect of the cooling control apparatus according to the present invention, the operating condition includes at least one of an engine speed and a load of the internal combustion engine.

  According to this aspect, the target rotational speed of the electric pump is determined according to at least one of the engine rotational speed and the load of the internal combustion engine. Here, the “load” is intended to be expressed by various index values correlated with the load of the internal combustion engine, such as an accelerator opening, a throttle opening, an intake air amount, or a load factor.

  The engine speed and load correlate with the degree of heat generation in the internal combustion engine, in other words, the degree of necessity of cooling. Thus, the target speed depends on at least one of the engine speed and the load, preferably both. When the number is set, the electric pump is efficiently and effectively used as a more specific example, for example, the circulation supply amount of cooling water as a concept including the discharge amount or the rotation speed of the pump, etc., as much as possible. It is possible to drive so as to be minimized. That is, it becomes possible to use power resources effectively.

  In another aspect of the cooling control apparatus according to the present invention, the second control unit is configured to perform the intermittent operation when a state where the actual rotational speed is higher than the target rotational speed continues for a predetermined time or more. Control the electric pump.

  When intermittent operation is performed, the circulating supply amount of the cooling water relatively decreases, so that the electric pump can be protected, but the water injection rate of the cooling water tends to decrease. According to this aspect, the actual rotational speed of the electric pump exceeds the target rotational speed for some temporary reason different from air biting, or even if air biting occurs, it has been eliminated in a sufficiently short period of time, etc. Since it is possible to reliably prevent the malfunction of the electric pump caused by the heat load while suppressing the execution of the intermittent operation in a situation where the necessity for the intermittent operation is low, it is practically beneficial.

In another aspect of the cooling control apparatus according to the present invention, the second control unit is configured such that when at least a part of the water injection is performed, a predetermined input indicating that the water injection is to be executed is made. The electric pump is controlled according to the deviation .

  According to this aspect, it is preferable because it is possible to easily and accurately determine whether or not the water is being poured based on the predetermined input. Note that “when input is made” means, for example, that a physical operation means such as a button, a switch, a knob, a lever, or a dial installed in the passenger compartment is intended to inject water into the driver. If it is operated artificially based on this, or without such artificial operation, for example, by using some control device or controller, etc., it is possible to maintain the accuracy to the extent that there is no practical problem as to whether or not it is during water injection. This is a broad concept including a case where, for example, an electrical signal, a command, or the like is automatically output in accordance with a determination criterion or the like that is determined to be discriminable.

  In another aspect of the cooling control apparatus according to the present invention, the target rotation speed determination means determines the target rotation speed so that the target rotation speed is higher when the water injection is performed than when the water injection is not performed. To do.

  According to this aspect, when water injection is performed, the target rotational speed is set relatively high, so that the circulating supply amount of cooling water is relatively increased and water injection is improved. In this case, preferably, at least a part other than at the time of water injection, the target rotational speed of the electric pump may be determined so that the usage amount of the electric power resource can be suppressed as much as possible. This is preferable because the driving state of the electric pump is controlled efficiently and effectively.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

<Embodiment of the Invention>
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate.

<Configuration of Embodiment>
First, with reference to FIG. 1, the structure of the vehicle 10 which concerns on one Embodiment of this invention is demonstrated. FIG. 1 is a schematic configuration diagram conceptually showing the configuration of the vehicle 10.

  In FIG. 1, the vehicle 10 includes an ECU 100, an engine 200, a cooling device 300, and a water injection button 400.

  The ECU 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown), and is configured to be able to control the entire operation of the vehicle 10 according to the present invention. It is an example of a “cooling control device”. The ECU 100 is configured to be able to execute a discharge amount control process and an air biting detection process, which will be described later, according to a control program stored in the ROM.

  The engine 200 is a gasoline engine as an example of the “internal combustion engine” according to the present invention. Here, a detailed configuration of the engine 200 will be described with reference to FIG. Here, FIG. 2 is a schematic diagram of the engine 200. In FIG. 2, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof is omitted as appropriate.

  In FIG. 2, an engine 200 burns an air-fuel mixture through an ignition operation by an ignition device 202 in which a part of a spark plug (not shown) is exposed in a combustion chamber in a cylinder 201, and an explosive force due to such combustion. The reciprocating motion of the piston 203 that occurs in response to the above is converted into the rotational motion of the crankshaft 205 via the connecting rod 204. A crank position sensor 206 that detects the rotational position (ie, crank angle) of the crankshaft 205 is installed in the vicinity of the crankshaft 205. The crank position sensor 206 is electrically connected to the ECU 100, and the ECU 100 is configured to be able to control the ignition timing and the like of the ignition device 202 based on the crank angle detected by the crank position sensor 206. Yes. Further, the ECU 100 is configured to be able to calculate the engine speed Ne of the engine 200 based on the rotational position of the crankshaft 205.

  In the engine 200, the air sucked from the outside passes through the intake pipe 207 and is mixed with the fuel injected from the injector 214 at the intake port 213 to become the above-mentioned air-fuel mixture. The fuel is stored in the fuel tank 215, and is supplied by pressure to the injector 214 via the delivery pipe 216 by the action of the feed pump 217. The injector 214 is electrically connected to the ECU 100, and is configured to be able to inject the supplied fuel into the intake port 213 according to the control of the ECU 100. The form of the injection means for injecting the fuel does not have to adopt a so-called intake port injector configuration as shown in the figure. For example, the pressure of fuel pumped by a feed pump or other low-pressure pump is further increased by a high-pressure pump. It may have a form such as a so-called direct injection injector configured to be able to directly inject fuel into the high-temperature and high-pressure cylinder 201.

  The communication state between the inside of the cylinder 201 and the intake pipe 207 is controlled by opening and closing the intake valve 218. The air-fuel mixture combusted inside the cylinder 201 becomes exhaust and is led to the exhaust pipe 221 via the exhaust port 220 when the exhaust valve 219 that opens and closes in conjunction with the opening and closing of the intake valve 218 is opened.

  On the other hand, a cleaner 208 is disposed on the intake pipe 207 to purify the air sucked from the outside. An air flow meter 209 is further disposed on the downstream side (cylinder side) of the cleaner 208. The air flow meter 209 has a form called a hot wire type, and is configured to be able to directly detect the mass flow rate of the sucked air. The air flow meter 209 is electrically connected to the ECU 100, and the detected mass flow rate of the intake air is determined by the ECU 100 continuously or at a constant or indefinite period.

  A throttle valve 210 that adjusts the amount of intake air related to the air sucked into the cylinder 201 is disposed downstream of the air flow meter 209 in the intake pipe 207. A throttle position sensor 212 is electrically connected to the throttle valve 210, and is configured to be able to detect the throttle opening that is the opening.

  The slot valve motor 211 is a motor that is electrically connected to the ECU 100 and configured to drive the throttle valve 210. The ECU 100 controls the drive state of the throttle valve motor 211 based on an operation amount of an unillustrated accelerator pedal (hereinafter referred to as “accelerator opening” or the like as appropriate) detected by an accelerator position sensor 11 provided in the vehicle 10. Thus, the open / close state of the throttle valve 210 (that is, the throttle opening) is controlled. The throttle valve 210 is a kind of electronically controlled throttle valve as described above, and the throttle opening degree can be controlled by the ECU 100 regardless of the driver's intention (that is, the accelerator opening degree).

  A three-way catalyst 223 and an underfloor catalyst 224 are installed in the exhaust pipe 221. The three-way catalyst 223 is a catalyst capable of purifying CO (carbon monoxide), HC (hydrocarbon), and NOx (nitrogen oxide) discharged from the engine 200, respectively. The underfloor catalyst 224 is a three-way catalyst installed under the floor of the vehicle 10 and is configured to remarkably remove, for example, NOx that cannot be removed by the three-way catalyst 223.

  An air-fuel ratio sensor 222 is disposed upstream of the three-way catalyst 223 in the exhaust pipe 221. The air-fuel ratio sensor 222 is configured to detect the air-fuel ratio of the engine 200 from the exhaust gas discharged through the exhaust port 220. The air-fuel ratio sensor 222 is electrically connected to the ECU 100, and the detected air-fuel ratio is grasped by the ECU 100 constantly or at a constant or indefinite period. A water temperature sensor 225 for detecting the temperature of cooling water (cooling water temperature) that is circulated and supplied mainly for cooling the engine 200 is disposed on the water jacket installed in the cylinder block that houses the cylinder 201. ing. The water temperature sensor 225 is electrically connected to the ECU 100, and the detected coolant temperature is grasped by the ECU 100 constantly or at a constant or indefinite period.

  Referring back to FIG. 1, the cooling device 300 mainly includes an electric water pump (hereinafter, appropriately referred to as “electrical W / P”) 310, a cooling water circulation path 320, a thermostat 330, and a radiator 350. Is an example.

  The electric W / P 310 is a spiral pump as an example of the “electric pump” according to the present invention. The electric W / P 310 sucks the cooling water by the rotational force of a motor (not shown) and has an amount corresponding to the rotational speed of the motor (that is, the rotational speed, which is an example of the “rotational speed of the electric pump” according to the present invention). The cooling water can be discharged.

  The motor is supplied with electric power from a power supply source (not shown) (for example, a 12V battery for vehicle mounting or another battery) and the like, and receives a control voltage (or current) supplied via a motor drive system (not shown). ) Is controlled to increase or decrease in accordance with the duty ratio DTY. In addition, this motor drive system is in a state of being electrically connected to the ECU 100, and the operation state including the above-described duty ratio DTY is controlled by the ECU 100. That is, the operation state of the electric W / P 310 is controlled by the ECU 100.

  On the other hand, the rotational speed of the motor in the electric W / P 310 (hereinafter referred to as “pump rotational speed Rp” as appropriate) is detected by a rotation sensor 311 disposed in the vicinity of the electric W / P 310. The rotation sensor 311 is electrically connected to the ECU 100, and the detected pump rotation speed Rp is grasped by the ECU 100 constantly or at a constant or indefinite period.

  The cooling water circulation path 320 is a pipe member made of, for example, metal or resin, including the above-described water jacket stretched around the cylinder block, and defining a supply path of cooling water discharged by the electric W / P 310. The cooling water circulation path 320 includes a branch pipe 340 that branches to the radiator 350 in the thermostat 330, and a branch pipe 360 that returns from the radiator 350 to the thermostat 330.

  The thermostat 330 is a temperature adjusting means provided for stabilizing the cooling water temperature. Inside the thermostat 330, a control valve for controlling the communication state between the branch pipes 340 and 360 communicating with the radiator 350 and the main pipe of the cooling water circulation path 320 is provided. The flow rate of the cooling water flowing into the radiator 350 can be adjusted by controlling the opening / closing state of the valve body of the control valve. The thermostat 330 is electrically connected to the ECU 100, and its operation is controlled by the ECU 100 to the upper level. For example, the control valve is configured to be fully closed when the cooling water temperature is lower than a predetermined value, and to be fully opened when the cooling water temperature is equal to or higher than the predetermined value. Yes.

  When the control valve is closed by the thermostat 330, the flow of cooling water in the thermostat 330 is as shown by the broken line in the figure. On the other hand, when the control valve is opened by the thermostat 330, the flow of cooling water in the thermostat 330 is as shown by the solid line in the figure.

  The radiator 350 includes a plurality of water pipes arranged in communication with the branch pipes 340 and 360, and includes a large number of corrugated fins on the outer periphery of the water pipe, and the cooling water flows through the water pipe. At this time, the cooling water can be relatively cooled by heat exchange with the atmosphere via the fins, that is, by dissipating the heat of the cooling water to the outside.

  The water injection button 400 is an operating means that is installed, for example, on a console panel or the like in the passenger compartment to enable operation by a driver or the like, and the cooling water discharge mode is set between a water injection mode and a fuel saving mode described later. It is possible to switch between them. The water injection button 400 can transmit to the ECU 100 via the electrical signal that the water injection mode has been selected while being pressed, and that the fuel saving mode has been selected without being pressed. It is configured. That is, the water injection button 400 is configured to be able to make a “predetermined input indicating that water injection should be performed” according to the present invention.

<Operation of Embodiment>
The cooling water discharge amount of the electric W / P 300 in the cooling device 300 is controlled by a discharge amount control process executed by the ECU 100. Here, the details of the discharge amount control process will be described with reference to FIG. FIG. 3 is a flowchart of the discharge amount control process.

  In FIG. 3, the ECU 100 determines whether or not the ignition is on (step S101). That is, it is determined whether or not there is a request for starting the engine 200. If the ignition is not on (step S101: NO), the ECU 100 waits without starting the engine 200.

  If the ignition is on (step AS101: YES), the ECU 100 starts the engine 200 and acquires the engine speed NE and the accelerator opening Acc (step S102). At this time, the ECU 100 acquires the engine rotational speed NE as a result of numerical calculation based on the rotational state of the crankshaft 205 detected by the crank position sensor 206, and calculates the accelerator opening Acc input from the accelerator position sensor 11. get. The engine speed NE may be acquired via a detection unit such as an NE sensor that detects the rotation speed of the crankshaft 205 or the like.

  Note that the processing according to step S102 is repeatedly executed at a predetermined cycle thereafter. That is, the ECU 100 substantially continuously acquires the engine speed NE and the accelerator opening Acc.

  Next, the ECU 100 determines whether or not the water injection mode is selected via the water injection button 400 (step S103). When the water injection mode is not selected (step S103: NO), that is, when the fuel saving mode is selected regardless of the presence or absence of the driver's positive intention, the ECU 100 performs the electric power W corresponding to the fuel saving mode. The target rotational speed RpB, which is the target value of the pump rotational speed Rp of / P310, is determined (step S105).

  Here, the details of the target rotation speed RpB will be described with reference to FIG. FIG. 4 is a schematic diagram conceptually showing a map that defines the target rotational speed RpB.

  In FIG. 4, the map that defines the target rotational speed RpB is a coordinate system in which the vertical axis and the horizontal axis are respectively arranged with the accelerator opening Acc (that is, an example of “load” according to the present invention) and the engine rotational speed NE. It is formed by arranging the target rotation speed RpB in a matrix on the top. In FIG. 4, as the target rotational speed RpB, the target rotational speeds up to RpB1, RpB2 (RpB2> RpB1),..., RpBN (RpBN> RpB (N-1)),. Is set. As is apparent from the level relationship between these target rotational speeds RpB, the constant rotational lines (see the broken lines in the figure) connecting the target rotational speeds equal to each other in the map are equal to each other from the lower left to the upper right in FIG. Arrange at intervals. That is, in the upper right part of the map shown in FIG. 4 (that is, the operation region corresponding to the high rotation and high load), the target rotation speed RpB is the highest value.

  In the process according to step S105 of FIG. 3, the ECU 100 selectively acquires values corresponding to the engine speed NE and the accelerator opening Acc acquired at step S102 from the map related to the target speed RpB, The rotational speed RpB is determined. Here, each target rotation speed RpB in the map is set as low as possible in order to save the amount of power used by the power supply source that supplies power to the electric W / P 310. Therefore, the amount of electric power used is suppressed by referring to the map, and the fuel consumption of the engine 200 can be improved. That is, fuel saving is realized.

  Returning to FIG. 3, when the target rotational speed RpB is set, the ECU 100 sets the duty ratio DTY of the voltage supplied to the electric W / P 310 so that the pump rotational speed Rp of the electric W / P 310 becomes the target rotational speed RpB. And the motor drive system described above is controlled in accordance with the determined duty ratio DTY, so that the electric W / P 310 is normally operated (step S106). Here, the normal operation is opposed to the intermittent operation described later, and refers to a normal operation mode in which the electric W / P 310 is operated so as to obtain the determined target rotational speed.

  The duty ratio DTY is set in a form associated with the pump speed Rp in a duty ratio map stored in advance in the ROM, and the ECU 100 determines the target speed RpB determined from the duty ratio map. The duty ratio DTY is determined by selectively acquiring one duty ratio DTY corresponding to.

  On the other hand, when it is determined in the determination process according to step S103 that the water injection mode has been selected (step S103: YES), the ECU 100 uses the target value of the pump rotation speed Rp of the electric W / P 310 corresponding to the water injection mode. A certain target rotational speed RpA is determined (step S104).

  Here, the details of the target rotational speed RpA will be described with reference to FIG. FIG. 5 is a schematic configuration diagram conceptually showing the characteristic of the target rotation speed RpA.

  In FIG. 5, the target rotational speed RpA and the engine rotational speed NE or the accelerator opening Acc are arranged on the vertical axis and the horizontal axis, respectively. The target rotational speed RpA takes a lower limit RpA1 that is low enough to prevent the electric W / P 310 from stalling in an operating region where the engine rotational speed NE is low (for example, about 1000 rpm) or the accelerator opening degree Acc is small. In the region, the engine linearly increases with respect to the engine speed NE or the accelerator opening degree Acc. A map corresponding to the characteristics shown in FIG. 5 is stored in advance in the ROM of the ECU 100. In the processing according to step S104 in FIG. 3, the ECU 100 sets the target corresponding to the value of the engine speed NE or the accelerator opening Acc. The target rotational speed RpA is determined by selectively acquiring the rotational speed RpA.

  The characteristic of the target rotational speed as shown in FIG. 5 is equivalent to that of a mechanical pump that can be rotationally driven with the rotation of the crankshaft 205 of the engine 200, for example. This is a characteristic that is imparted so that the pump rotational speed Rp increases when one of the engine rotational speed and the load is high. Therefore, in the fuel saving mode described above, the target rotational speed RpA is generally higher than the target rotational speed RpB determined so that the electric power resources can be used more efficiently based on the engine rotational speed NE and the accelerator opening degree Acc. Value.

  Thus, since the target rotational speed RpA takes a higher value than the target rotational speed RpB, the utilization efficiency of the electric power resource is not necessarily optimized in the water injection mode, but on the other hand, the cooling water discharge in the electric W / P 310 is performed. Since the amount is relatively increased, for example, water can be effectively and efficiently injected into a reservoir (not shown in FIG. 1) for storing cooling water or a cooling water circulation path 320 that easily adopts a complicated physical shape as a whole. Is possible. That is, when the pump rotation speed Rp of the electric W / P 310 is controlled to the target rotation speed RpA determined according to the water injection mode, the water injection efficiency of the cooling water is improved.

  Returning to FIG. 3, when the target rotational speed RpA is determined, the ECU 100 proceeds to step S106, determines the duty DTY corresponding to the target rotational speed RpA, as in the execution of the fuel saving mode, and performs the electric W / W The electric W / P 310 is normally operated by controlling the electric W / P 310 so that the pump rotational speed Rp of P310 becomes the target rotational speed RpA.

  When the electric W / P 310 is normally operated at least temporarily in this manner, the ECU 100 next determines whether or not the air bit flag FG is set to ON (step S107). Here, the air biting flag FG is a flag that is turned on when it is estimated that air biting accompanying water injection occurs in the electric W / P 310, and is executed by the ECU 100 in parallel with the discharge amount control process. It is set appropriately by the air biting detection process. Here, the details of the air biting detection process will be described with reference to FIG. FIG. 6 is a flowchart of the air biting detection process.

  In FIG. 6, the ECU 100 determines whether or not the water injection mode is selected via the water injection button 400 (step S201). That is, this process is equivalent to the process related to step S103 in the discharge amount control process.

  When the water injection mode is not selected (step S201: NO), the ECU 100 unconditionally sets the air bit flag FG to off (step S206).

  On the other hand, when the water injection mode is selected (step S201: YES), the ECU 100 acquires the target rotation speed RpA determined in the discharge amount control process (step S202). Subsequently, the ECU 100 acquires the pump rotation speed Rp of the electric W / P 310 from the rotation sensor 311 (that is, an example of “actual rotation speed” according to the present invention) (step S203).

  When the actual rotational speed Rp is acquired, the ECU 100 calculates the rotational speed deviation ΔRp and determines whether the rotational speed deviation ΔRp is larger than a predetermined threshold value ΔRpth (step S204). Here, the rotational speed deviation ΔRp is a value obtained by subtracting the target rotational speed RpA from the pump rotational speed Rp.

  When air clogging occurs, due to the difference in viscosity resistance between cooling water and air, more specifically, when the air clogging occurs, the viscous resistance that inhibits the rotation of the motor decreases, so the pump rotation speed Rp tends to be higher than the target rotational speed RpA. Therefore, the rotational speed deviation ΔRp that can represent how much the actual rotational speed of the electric W / P 310 deviates from the target rotational speed can be used as an index for determining the degree of air engagement. When the rotational speed deviation ΔRp is equal to or smaller than the threshold value ΔRpth (step S204: NO), the ECU 100 sets the air bit flag FG to be off (step S206), assuming that no air bit is occurring.

  On the other hand, when the rotation speed deviation ΔRp is larger than the threshold value ΔRpth (step S204: YES), the ECU 100 sets the air bit flag FG to be on (step S205), assuming that the electric W / P 310 is air bit. . When the air biting flag FG is set, the ECU 100 returns the process to step A201 and repeatedly executes a series of processes.

  Here, the rotational speed deviation ΔRp is, for example, experimentally, empirically, theoretically or based on a simulation or the like in advance. Although it can be estimated that air biting has not occurred or it has been determined that it cannot be estimated that it has occurred, or no air biting has occurred or it can be estimated that no air biting will occur. The air biting occurs when it is larger than a threshold value ΔRpth that is set so that the air biting can be determined to such an extent that the air biting has occurred or that it is estimated that the air biting is likely to occur). Although the determination to this effect is made, the mode of determination related to the occurrence of air biting is not limited to this. For example, the ECU 100 determines that the air biting has occurred when the rotation speed sensor ΔRp is continuously greater than the threshold value ΔRpth or another threshold value different from the threshold value ΔRpth for a predetermined allowable time or longer. Also good.

  Returning to FIG. 3, when the air bit flag FG is OFF (step S107: NO), the ECU 100 proceeds to step S103 and repeats a series of processes. At this time, if the water injection mode is continued, the pump rotation speed Rp is controlled to be the target rotation speed RpA, and if the water injection mode is ended, the pump rotation speed Rp is controlled to be the target rotation speed RpB. Is done.

  On the other hand, when the air bit flag FG is set to ON (step S107: YES), the ECU 100 is electrically operated to prevent malfunction of the electric W / P 310 due to air biting, for example, seizure of a rotating shaft, a bearing or the like in the motor. The W / P 310 is intermittently operated (step S108).

  Here, the details of the intermittent operation will be described with reference to FIG. FIG. 7 is a characteristic diagram showing the time characteristic of the duty ratio DTY of the electric W / P 310 during intermittent operation.

  In FIG. 7, the vertical axis and the horizontal axis represent the duty ratio DTY and time, respectively. As is clear from FIG. 7, when intermittent operation is performed in the present embodiment, an operation period in which the electric W / P 310 is operated (for example, illustrated times T1 to T2, T3 to T4, T5 to T6, T7 to T8, and A period corresponding to T9 to T10) and a stop period in which the electric W / P 310 is stopped (that is, a period in which the duty ratio is set to zero, and illustrated times 0 to T1, T2 to T3, T4 to T5, T6 to The electric W / P 310 is controlled so as to alternate between the periods corresponding to T7 and T8 to T9.

  In this embodiment, the operation period and the stop period are the same length as each other, and a period defined by one operation period and one stop period adjacent to each other is expressed as “turn” for convenience. As shown in the figure, the turn is repeated every time ΔTbase. In addition, when a time ΔT corresponding to five turns elapses, one intermittent operation ends.

  In particular, when each turn is expressed as a first turn, a second turn, a third turn, a fourth turn, and a fifth turn in order from the left in FIG. 7, the duty ratio DTYn ( The size of n = 1, 2,..., 5) is DTYn> DTYn−1 (n = 2, 3, 4, 5), and during one intermittent operation, the duty ratio DTY is the time It is set so as to increase gradually as time passes.

  The duty ratio DTY during intermittent operation may be equal to each other at each turn. Also in this case, protection of the electric W / P 310 at the time of water injection is sufficiently secured in practice. Further, during the intermittent operation, the operation period and the stop period come alternately, for example, so that the pulsation of the cooling water discharged from the electric W / P 310 is likely to occur, and the above-described performance recovery of the cooling device 300 can be sufficiently achieved.

  Note that the length of each turn during intermittent operation and the ratio between the operation period and the stop period in each turn may be variable depending on, for example, the degree of air biting. The degree of air biting may be set in advance in a plurality of stages or continuously in accordance with, for example, the magnitude of the rotational speed deviation ΔRp described above.

  Returning to FIG. 3, when the W / P 310 is intermittently operated, the ECU 100 determines whether or not the above-described one-time intermittent operation is completed (step S109). When one intermittent operation is continuing (step S109: NO), the ECU 100 repeatedly executes the processing according to step S108, and when one intermittent operation is completed (step S109: YES), the ECU 100 The process returns to step S103. At this time, if it is determined in the air biting detection process that the air biting has been eliminated, that is, if the air biting flag FG is set to OFF, normal operation according to the target rotational speed RpA is performed again, and the air If it is not determined that the bite has been eliminated, the intermittent operation is executed again. The discharge amount control process is executed as described above.

  When such an intermittent operation is performed, first, the operation period and the stop period are alternately visited, so that the electric W / P 310 can be relatively viewed and cooled. It is possible to prevent the occurrence of various problems such as image sticking. In addition, since the period during which the electric W / P 310 is in operation is shorter than the normal operation described above, it is possible to efficiently use power resources and improve fuel consumption. For example, when priority is given to the protection of the electric W / P 310, the operation period and the stop period may not be set to the same length, for example, the stop period is about several tens of seconds with respect to the operation period of several seconds. It may be provided.

  Further, in the present embodiment, the duty ratio DTY during intermittent operation is set in advance to be suitable for intermittent operation, unlike the duty ratios corresponding to the target rotational speeds RpB and RpA in the fuel saving mode and the water injection mode, for example, For example, it is set to a fixed value stored in a ROM or the like. At this time, since the duty ratio is gradually increased during the intermittent operation as described above, while the electric W / P 310 is protected, in the process of gradually increasing the duty ratio, that is, in any turn, There is a relatively high possibility that an air reservoir or the like that is a factor will be removed. That is, when intermittent operation is performed in this way, in addition to protecting the electric W / P 310 and effectively using power resources, the performance recovery of the cooling device 300 is actively promoted, which is extremely useful in practice. It is.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. Moreover, it is included in the technical scope of the present invention.

1 is a schematic configuration diagram conceptually illustrating a configuration of a vehicle according to an embodiment of the present invention. It is a schematic diagram of the engine in the vehicle of FIG. 2 is a flowchart of a discharge amount control process executed by an ECU in the vehicle of FIG. It is a schematic diagram conceptually showing a map that defines a target rotation speed RpB determined in the discharge amount control process. FIG. 3 is a schematic configuration diagram conceptually showing characteristics of a target rotation speed RpA determined in a discharge amount control process. 2 is a flowchart of an air biting detection process executed by an ECU in the vehicle of FIG. It is a characteristic view showing the time characteristic of duty ratio DTY at the time of intermittent operation performed in discharge amount control processing.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 100 ... ECU, 200 ... Engine, 300 ... Cooling device, 310 ... Electric power W / P, 320 ... Cooling water circulation path, 330 ... Thermostat, 340 ... Branch pipe, 350 ... Radiator, 360 ... Branch pipe, 400 ... Water injection button.

Claims (5)

A cooling control device that includes an electric pump and controls a cooling device capable of cooling the cooled system by circulatingly supplying cooling water to the cooled system including the internal combustion engine by the electric pump,
Target rotational speed determination means for determining a target rotational speed of the electric pump according to predetermined operating conditions in the internal combustion engine;
First control means for controlling the electric pump so that the rotational speed of the electric pump becomes the target rotational speed;
An actual rotational speed specifying means for specifying the actual rotational speed of the electric pump;
Second control for controlling the electric pump so that intermittent operation is performed when a deviation between the target rotational speed and the actual rotational speed is equal to or greater than a predetermined allowable value when the cooling water is injected. And a cooling control device. The cooling control device according to claim 1, wherein the operating condition includes at least one of an engine speed and a load of the internal combustion engine. The said 2nd control means controls an electric pump so that the said intermittent operation may be performed when the state where the said actual rotation speed is higher than the said target rotation speed continues more than predetermined time. Or the cooling control apparatus of 2. The second control means controls the electric pump according to the deviation when a predetermined input indicating that the water injection should be performed is made as at least a part of the case where the water injection is performed. The cooling control apparatus according to any one of claims 1 to 3 , wherein the cooling control apparatus is characterized in that: The target rotational speed determining means, when the water injection is carried out, any of claims 1 to 4, characterized by determining the target rotational speed to be higher as compared with the case where the water injection is not performed The cooling control device according to claim 1.

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