JP4146372B2 - Cooling system control method for vehicle power source - Google Patents

Description

  The present invention relates to a cooling system control method for a vehicle power source such as an engine mounted on an automobile.

  As a conventional method for controlling a cooling system of a vehicle power source, for example, there is a cooling device for a liquid-cooled internal combustion engine disclosed in Patent Document 1. In this conventional technique, in a cooling system with a heater in a passenger compartment, the cooling water is circulated to the heater core side when the heater is turned on, and the cooling water is not circulated to the heater core side when the heater is turned off. In addition, in order to control the cooling water temperature, the pump flow rate and the amount of water to be circulated to the radiator are adjusted by the deviation between the target water temperature and the actual water temperature to improve the warm-up performance at the time of cold start. At the same time, it aims to reduce exhaust gas, improve fuel efficiency, improve heating performance and reduce pump current consumption.

JP 2001-248439 A

  Since the conventional cooling system control method for an internal combustion engine is configured as described above, it has the following problems. During the cooling water temperature control, the pump rotation speed and the valve opening are adjusted according to the deviation between the target water temperature and the actual water temperature. However, the driving state and environmental conditions of the vehicle vary, and even in the same driving state, the change in water temperature varies depending on the water temperature, temperature, and water volume (pump rotation speed). Further, when the valve passage is switched to change the water passage, the circulating water capacity of the cooling system changes. Before and after the water capacity change, the change in water temperature is different even in the same engine operating state.

  That is, even if the deviation between the target water temperature and the actual water temperature is 10 ° C., for example, the control amount varies depending on the operating conditions, environmental conditions, and cooling system capacity. However, when the cooling system is controlled based on the water temperature deviation, that is, when the pump rotation speed and the valve opening are adjusted based on the water temperature deviation, the pump rotation speed and the valve opening depend on the water temperature deviation. In other words, even if the passage of the cooling system is changed by changing the valve opening and the capacity of the cooling water circulating in the cooling system is changed, the pump speed and the valve opening are the same as long as the water temperature deviation is the same. Control value. This indicates that the followability of the water temperature is different depending on the passage configuration of the cooling system, and occurs when the followability is not good. Even when the engine operating conditions change, the heat dissipation given to the cooling system of the engine differs, so that good controllability may not be obtained.

  As described above, in the conventional technique, the cooling system is controlled based on the water temperature deviation, and the amount of cooling water circulating through the cooling system path at that time, the flow rate of cooling water, and the like are not taken into consideration. This is a control that depends on the current cooling water temperature, and does not incorporate a future control element that occurs when the state changes. For this reason, when the control state changes as described above, a phenomenon in which the water temperature rapidly decreases occurs. For the engine, a rapid temperature change should not be desirable, and it may adversely affect the internal combustion engine body, such as distortion, and may cause a deterioration in fuel consumption and exhaust gas due to a temporary decrease in cooling water temperature.

  In addition, in the conventional technique, it is necessary to manage the water temperature at two locations of the pump inlet water temperature and the bypass water temperature, and a plurality of water temperature sensors are required, which raises a problem that the system cost increases. The valve opening / closing differs between heater priority control and warm-up priority control. However, when switching from heater priority control to warm-up priority control, the water passage is suddenly closed when the valve is suddenly moved from opening to closing. As a result, a water hammer occurs, and in the worst case, the valve or pump may be destroyed.

A vehicle power source cooling system control method according to the present invention includes a vehicle power source rotation speed detecting means for detecting the rotation speed of a rotating shaft attached to a vehicle power source and rotating in synchronization with the vehicle power source; The vehicle power source rotation speed calculation means for calculating the rotation speed of the vehicle power source from the detection signal of the rotation speed detection means, the water temperature sensor for detecting the cooling water temperature of the vehicle power source, and the tire axis of the vehicle. Vehicle speed calculating means for detecting the rotation speed and calculating the vehicle speed, a water pump attached to the cooling water path of the vehicle power source and circulating the cooling water, and the discharge of the water pump based on the rotation speed of the water pump A water pump flow rate calculating means for calculating a flow rate, a radiator for heat exchange of the cooling water, a radiator fan for adjusting a wind speed passing through the radiator, and the radiator A radiator fan control device that adjusts the wind speed of the fan, a heater core that exchanges heat with the cooling water to adjust the vehicle interior temperature of the vehicle, and the cooling water that is output from the cooling water outlet of the vehicle power source. A bypass passage that circulates to the cooling water inlet of the vehicle power source without going through the vehicle, and an opening area of the passage is changed to divert the flow rate of the cooling water of the vehicle power source between the radiator side and the bypass side. An adjustment valve for adjusting the shunt flow rate, passage area adjusting means for adjusting the passage area of the bypass passage attached to the bypass passage, and electronic control for controlling the adjustment valve and the passage area adjusting means and a device, the cooling system heat cooling system of the vehicle power source store and to the vehicle power source radiation amount of the vehicle power source to radiate according to the operating conditions The total heat quantity of the cooling system is estimated, and based on the total heat quantity of the cooling system and the target cooling system total heat quantity calculated from the target water temperature determined by the operation state of the vehicle power source, the target heat dissipation amount in the radiator it is obtained to perform the cooling system control by determining the.

  In this invention, the control of the cooling system is managed by the amount of heat, and the total amount of heat of the cooling system is estimated from the amount of heat of the cooling system stored by the cooling system of the engine and the amount of heat released from the engine according to the operating state. Since it did in this way, the heat quantity of the cooling water which changes with the circulating water quantity of a cooling system can be managed, and water temperature control with sufficient precision can be performed.

Embodiment 1 FIG.
FIG. 1 shows the configuration of an engine that is a vehicle power source. The engine 101 is attached to an intake passage through an electronically controlled throttle valve 102 that changes the intake passage opening according to the driver's accelerator operation. Inhale. The crank angle of the engine 101 is detected by a crank angle sensor 103 that is attached in the vicinity of the crank angle vane attached to the crankshaft and detects an angle signal of the crank angle vane. A fuel control valve 104 is provided in the intake passage of the engine 101, and this is a fuel injection amount calculated from engine speed information calculated from detection information of the crank angle sensor 103 and engine operation information such as engine load and water temperature. Based on the above, fuel is injected into the intake pipe. Further, ignition control means 105 for controlling the ignition timing based on the ignition timing calculated based on the engine operation information is provided, and the engine control is performed by the electronic control unit 106.

  Next, FIG. 2 shows the system configuration of the engine cooling system according to the present invention, which will be described based on the drawing. This figure is a view of the system viewed from the upper side of the engine 101. The amount of cooling water flowing through the cooling system of the engine 101 is electrically adjusted by the electric water pump 201. A radiator 202 is connected to the cooling system of the engine 101 through a radiator upper hose 203 and a radiator lower hose 204. An adjustment valve (hereinafter referred to as a thermo valve) 206 that adjusts the diversion is attached to a joint portion between the cooling water outlet of the engine 101 and the radiator lower hose 204. Further, a bypass passage 205 is provided between the thermo valve 206 and the electric water pump 201, and the mixing ratio of the cooling water from the outlet of the engine 101 and the radiator lower hose 204 is adjusted by the opening degree of the thermo valve 206. .

  The opening degree of the thermo valve 206 is electrically controlled, and if the opening degree of the thermo valve is fully closed (the state indicated by the solid line in FIG. 2), the cooling water output from the engine 101 is all bypassed via the thermo valve 206. It flows into the passage 205. When the opening degree of the thermo valve 206 is fully open (the state indicated by the broken line in FIG. 2), engine cooling water is not output from the thermo valve 206, and engine cooling water is output from the radiator upper hose 203. The heat is exchanged and flows through the radiator lower hose 204 and the thermo valve 206 to the bypass passage 205. Further, the opening degree of the thermo valve 206 can be continuously (linearly) controlled. When the thermo valve opening degree is an intermediate opening degree, the thermo valve 206 is output from the thermo valve 206 portion. The cooling water that is output from the upper hose 203 portion and heat-exchanged by the radiator 202 is mixed in the bypass passage 205.

  The engine 101 is provided with a heater core 207 communicating with a heater in hose 208, and performs heat exchange with cooling water in order to supply warm air into the vehicle interior with an air conditioner. The heater core 207 communicates with the bypass passage 205 through a heater out hose 209. Thus, the cooling water output from the engine 101 returns to the bypass passage 205 through the passage as described above, and is sucked into the engine 101 by the water pump 201.

  A passage area adjusting means (hereinafter referred to as a passage switching valve) 210 is attached to the bypass passage 205 to change the passage area of the bypass passage 205. When the passage switching valve 210 is fully opened, the cooling water from the radiator 202 side and the cooling water from the heater core 207 side are mixed and returned to the water pump 201 as described above. When the passage switching valve 210 is fully closed, the cooling water does not flow from the radiator 202 side to the pump 201 side, so that all the cooling water flows to the bypass passage 205 via the heater core 207. The coolant temperature immediately before the pump 201 is detected by a water temperature sensor 211 provided on the wall surface of the bypass passage 205. The radiator 202 is cooled by a radiator fan 212, and the rotation speed of the radiator fan 212 is controlled by a radiator fan control device 213. The cooling system is controlled by the electronic control unit 106.

  Next, the control method of the present invention will be described based on the control block diagram of FIG. Control is performed by the electronic control unit 106. Reference numeral 301 denotes a block for performing filter processing of engine speed information (Ne) calculated from engine cycle information detected by the crank angle sensor 103 in the electronic control unit 106. Reference numeral 302 denotes a block for performing filter processing of engine load information (Pe) calculated by the electronic control unit 106. Although the driving state of the engine 101 is not constant and the vehicle running state changes frequently, the temperature change of the cooling water is slow, so that the driving information used for control of the cooling system is subjected to filter processing to obtain an average driving in the near future. The state is used.

An arithmetic expression in the block 301 for performing the filter processing of the engine rotation speed information is as follows.
Ne_h = C1 ・ Ne_h + (1−C1) ・ Ne
Ne_h: Engine speed after filtering
Ne: Instantaneous engine speed
C1: Filter constant

An arithmetic expression in the block 302 that performs the filter processing of the engine load information is as follows.
Pe_h = C2 ・ Pe_h + (1−C2) ・ Pe
Pe_h: Net average effective pressure after filtering
Pe: Instantaneous net average effective pressure
C2; filter constant Here, Pe (net average effective pressure) is used as an example of engine load information, but it can be replaced by, for example, charging efficiency or engine torque.

Similarly, reference numeral 303 denotes a block for filtering the vehicle speed information calculated by a detection signal from a vehicle speed sensor (not shown) in the electronic control unit 106, and the calculation formula is as follows.
Vs_h = C3 ・ Vs_h + (1-C3) ・ Vs
Vs_h; vehicle speed after filter
Vs: Instantaneous vehicle speed
C3: Filter constant

A block 304 determines the target water temperature. The target water temperature is determined by the following map using the filter information calculated above.
Twt = T1 (Ne_h, Pe_h)
Twt; target water temperature (℃)
T1 (Ne_h, Pe_h); Ne_h and Te_h map

Reference numeral 305 denotes a block that calculates a target cooling system heat quantity possessed by a cooling system in a range where the cooling water circulates with respect to the target water temperature. Using the target water temperature determined in block 304, the target cooling system heat quantity is calculated in block 305.
Tcq = Kc ・ (Twt + 273) ・ Vc
Tcq; target cooling system heat (Kcal)
Kc: Specific heat of coolant (Kcal / L)
Twt; target water temperature (℃)
Vc: Circulation cooling system capacity (L)
The numerical value 273 used in the formula is for converting the Celsius temperature into an absolute temperature.

Reference numeral 306 denotes an engine heat dissipation amount calculation block that calculates the amount of heat that the engine 101 radiates to the cooling system from the current operating state. The engine heat dissipation is calculated by the following calculation formula using the filter information described above.
qe = F1 (Pe_h, Ne_h)
qe: Engine heat dissipation (Kcal / hr)
Since the heat dissipation amount of the engine is determined from the engine load and the engine speed, the heat dissipation amount that the engine 101 gives to the cooling system is calculated by the function (F1).

A block 308 calculates the amount of heat of the cooling system held by the cooling system in the range where the current cooling water is circulating from the current water temperature. The amount of heat of the cooling system is calculated based on the water temperature detected by the water temperature sensor 211.
Qt = Kc ・ (Wt + 273) ・ Vc
Qt: Actual cooling system heat (Kcal)
Kc: Specific heat of coolant (Kcal / L)
Wt: Water temperature (℃)
Vc: Circulation cooling system capacity (L)

Reference numeral 307 denotes a block for calculating a cooling system heat amount (predicted amount) predicted from the calculated engine heat radiation amount and cooling system heat amount. The amount of heat released from the engine in addition to the current heat quantity of the cooling system is the future heat quantity of the cooling system. The cooling system heat quantity after the control cycle T (sec) is as follows.
Qn = Qt + qe ・ (T / 3600)
Qn: Prediction amount of cooling system heat (Kcal)
Qt: Actual cooling system heat (Kcal)
qe: Engine heat dissipation (Kcal / hr)
T: Control cycle (sec)

Reference numeral 309 denotes a block for calculating a target radiator heat dissipation amount. Here, the amount of heat that needs to be released by the radiator 202 is calculated based on the target cooling system heat amount and the predicted cooling system heat amount calculated above.
Trq '= Qn-Tcq
Trq ': Calorie deviation (Kcal)
Qn: Prediction amount of cooling system heat (Kcal)
Tcq; target cooling system heat (Kcal)

  The target radiator heat dissipation amount in the radiator 202 is set in accordance with the calorie deviation (Trq ′) obtained above. When the heat quantity of the actual cooling system is sufficiently lower than the target cooling system heat quantity, and it is necessary to further increase the heat quantity of the actual cooling system, cooling with the radiator 202 is not necessary. At this time, the heat radiation amount in the radiator 202 becomes zero.

(A) When Trq '<-C4 (when the predicted cooling system heat quantity is sufficiently lower than the target cooling system heat quantity)
Trq '' = 0
Trq ''; Real-time amount of target radiator heat dissipation (Kcal)
C4: Heat dissipation lower threshold (Kcal)

(B) When -C4 ≤ Trq '<C5 (when the predicted cooling system heat quantity is near the target cooling system heat quantity)
Trq '' = Trq '
Trq ''; Real-time amount of target radiator heat dissipation (Kcal)
C4: Heat dissipation lower threshold (Kcal)
C5: Heat dissipation upper threshold (Kcal)

  When the heat quantity of the actual cooling system is sufficiently higher than the target cooling system heat quantity, it is necessary to quickly dissipate heat from the radiator 202 to avoid combustion problems such as excessive knocking or overheating of the engine 101.

(C) When Trq '≥ C5 (when the predicted cooling system heat quantity is sufficiently higher than the target cooling system heat quantity)
In this case, since the predicted amount of heat of the cooling system is sufficiently higher than the target amount of heat of the cooling system, the target heat dissipation amount at the radiator is the maximum heat dissipation amount.
Trq '' = Trq (max)
Trq ''; Real-time amount of target radiator heat dissipation (Kcal)
Trq (max): Maximum radiator heat dissipation (Kcal)

  Reference numeral 310 denotes a block that feeds back the radiator heat dissipation amount so that the target cooling system heat amount matches the predicted cooling system heat amount when the actual cooling system heat amount is close to the target cooling system heat amount. The cooling system heat quantity used to calculate the radiator heat dissipation is calculated using the specific heat that depends on the cooling water concentration and the capacity of the cooling water, but in the market, the specific heat and capacity of the cooling water are not constant, and individual differences Need to absorb. This block has an individual difference absorption element.

(A) When Trq '<-C4 (when the predicted cooling system heat quantity is sufficiently lower than the target cooling system heat quantity)
Trq '''= 0

(B) When -C4 ≤ Trq '<C5 (when the predicted cooling system heat quantity is near the target cooling system heat quantity)
Trq '''= Ki * ΣTrq'
Trq '''; Target radiator heat dissipation F / B (Kcal)
C4: Heat dissipation lower threshold (Kcal)
C5: Heat dissipation upper threshold (Kcal)
Ki: integral gain ΣTrq '; calorie deviation integral value

  By adding an integral element ΣTrq 'for absorbing individual differences to Trq' obtained by calculation, individual differences between the target cooling system heat quantity and the predicted cooling system heat quantity are absorbed by F / B. A thermo valve opening degree to be described later can be adjusted. Here, an arithmetic expression for performing F / B by an integral term is used. However, the F / B method is not limited to this, and another method such as PI control in which weighting is changed depending on the amount of heat deviation can be used.

(C) When Trq '≥ C5 (When the predicted cooling system heat quantity is sufficiently higher than the target cooling system heat quantity)
Trq '''= 0
Trq '''; Target radiator heat dissipation F / B amount (Kcal)
From these, the target radiator heat dissipation amount is calculated as follows by adding the calculated values of blocks 309 and 310.
Trq = Trq '' + Trq '''
Trq: Target radiator heat dissipation (Kcal)
Trq ''; Target radiator heat dissipation amount in real time (Kcal)
Trq '''; Target radiator heat dissipation F / B amount (Kcal)

Reference numeral 311 denotes a block for calculating the radiator wind speed. The wind speed passing through the radiator 202 is calculated from the vehicle speed information calculated in the block 303 and the radiator fan rotation speed calculated using a rotation speed detection sensor (not shown) of the radiator fan 212.
Vr = T2 (Vs_h, Dr)
T2: Radiator wind speed calculation map
Vr: Radiator wind speed (m / s)
Dr: Radiant fan speed (rpm)

Reference numeral 312 denotes a block for calculating the flow rate of the water pump 201. The water pump flow rate is calculated by the electronic control unit 106 from the water pump rotation number calculated using a water pump rotation number detection sensor (not shown).
Fp = T3 (Np)
T3: Pump flow rate calculation map
Fp: Water pump discharge flow rate (L / min)
Np: Water pump speed (rpm)

Reference numeral 313 denotes a block for calculating a target radiator flow rate to be circulated to the radiator 202 from the target radiator heat radiation amount, the radiator wind speed, and the pump flow rate.
Tfr = T4 (Trq, Vr, Fp)
T4: Target radiator flow calculation map
Tfr: Target radiator flow rate (L / min)
Vr: Radiator wind speed (m / s)
Fp: Water pump discharge flow rate (L / min)

  A target thermo valve opening calculation block 314 calculates a thermo valve opening for controlling the thermo valve 206 in order to obtain a target radiator flow rate. In the cooling system control method of the present invention, the opening area on the engine outlet side differs depending on the switching valve. The thermo-valve opening is calculated from the engine outlet side opening, the pump flow rate, and the target radiator flow rate.

Assuming that the outlet side passage area is proportional to the flow rate, the relationship between the passage area and the flow rate is as follows.
Srt ・ Tos_r: So = Tfr: (Fp-Tfr)
Tos_r: Target thermo valve opening (%)
Tfr: Target radiator flow rate (L / min)
So: Engine outlet side opening area (other than radiator) (cm2)
Srt: Opening area when the thermo valve is fully open
Fp: Pump flow rate (L / min)

From this, transform the expression,
Tos_r = So · Tfr / (Srt · (Fp − Tfr))
It becomes.

Here, in order to prevent sensitive operation of the thermo valve opening, a filter is also applied to the target thermo valve opening, and the thermo valve opening Tos (n) calculated this time is the previously calculated thermo valve opening Tos ( Using n−1), the following calculation is performed.
Tos (n) = (1−C6) ・ Tos (n−1) + C6 ・ Tos_r
Tos (n): Target thermo valve opening (%)
Tfr: Target radiator flow rate (L / min) C6: Filter constant

When the target radiator heat dissipation is Trq '≥ C5 (when the predicted cooling system heat amount is sufficiently higher than the target cooling system heat amount), the target radiator heat dissipation is Trq (max). Is the maximum value.
Tos = Tos (max)
Tos (max): Maximum thermo-valve opening

  Reference numeral 315 denotes a block for calculating the target pump speed of the water pump 201. Here, the deviation between the information obtained by filtering the engine speed information (NE) and load information (Pe) described above, the actual water temperature detected by the water temperature sensor 211, and the target water temperature determined from the operating state of the engine (not shown). Determine the target pump speed.

  Next, a control method from the start of the cold machine will be described. FIG. 4 shows a state at the time of cold start. Here, the cooling system configuration is switched and controlled according to the water temperature, the state at the time of cooling is set to state (1), the state close to warming up is set to state (2), and the warming up state is set to state (3).

  First, the state (1) when cold is described. When the engine is cold, it is necessary to warm up the engine 101 quickly. Therefore, the opening of the thermo valve 206 is controlled so that the passage from the radiator lower hose 204 to the bypass passage 205 is fully closed. Further, the passage switching valve 210 is fully closed so that the circulation from the bypass passage 205 to the water pump 201 is stopped. Therefore, in this case, the cooling water discharged from the engine 101 reaches the water pump 201 through the heater-in hose 208, the heater core 207, and the heater-out hose 209, and the cooling water is introduced into the engine.

In the case of this cooling water circulation path, the target cooling system heat quantity is calculated as follows.
Tcq = Kc ・ (Twt + 273) ・ Vc1
Tcq; target cooling system heat (Kcal)
Kc: Specific heat of coolant (Kcal / L)
Twt; target water temperature (℃)
Vc1: Circulating cooling system capacity (L) in the cooling system configuration in state (1)

The actual cooling system heat quantity is as follows.
Qt = Kc ・ (Wt + 273) ・ Vc1
Qt: Actual cooling system heat (Kcal)
Kc: Specific heat of coolant (Kcal / L)
Wt: Water temperature (℃)
Vc1; Circulation cooling system capacity (L) in the cooling system configuration in state (1)

  In the state of FIG. 4, only the heater core 207 is circulated outside the engine 101, and since the cooling system capacity is small, the time required to warm up can be shortened. This state continues until the target water temperature (state (1)) is reached.

  When the water temperature exceeds the target water temperature (state (1)), the control is shifted to the state (2), so the configuration of the cooling system is changed as shown in FIG. In FIG. 5, the path from the radiator lower hose 204 to the bypass passage 205 remains completely closed in the thermo valve 206 as in FIG. 4. The passage switching valve 210 is increased in opening so that the cooling water is circulated from the bypass passage 205 to the water pump 201. Since the cooling system warm-up in the state of FIG. 4 has been completed, the cooling water in the bypass passage 205 is then warmed up.

In the case of this cooling water circulation path, the target cooling system heat quantity is calculated as follows.
Tcq = Kc ・ (Twt + 273) ・ Vc2
Tcq; target cooling system heat (Kcal)
Kc: Specific heat of coolant (Kcal / L)
Twt; target water temperature (℃)
Vc2: Circulation cooling system capacity (L) in the cooling system configuration in state (2)

The actual cooling system heat quantity is as follows.
Qt = Kc ・ (Wt + 273) ・ Vc2
Qt: Actual cooling system heat (Kcal)
Kc: Specific heat of coolant (Kcal / L)
Wt: Water temperature (℃)
Vc2: Circulation cooling system capacity (L) in the cooling system configuration in state (2)

  This state is continued until the target water temperature is reached (state (2)), whereby the cooling water warm-up except for the radiator path is completed.

  When the water temperature exceeds the target water temperature (state (2)), the control is shifted to the state (3), so the configuration of the cooling system is changed as shown in FIG. 6 (state (3)). In FIG. 6, the passage switching valve 210 remains open as in FIG. The thermo valve 206 performs opening degree control in order to realize the target radiator flow rate, and controls the water temperature to be a target value.

In the case of this cooling water circulation path, the target cooling system heat quantity is calculated as follows.
Tcq = Kc ・ (Twt + 273) ・ Vc3
Tcq; target cooling system heat (Kcal)
Kc: Specific heat of coolant (Kcal / L)
Twt; target water temperature (℃)
Vc3: Circulation cooling system capacity (L) in the cooling system configuration in state 3

The actual cooling system heat quantity is as follows.
Qt = Kc ・ (Wt + 273) ・ Vc3
Qt: Actual cooling system heat (Kcal)
Kc: Specific heat of coolant (Kcal / L)
Wt: Water temperature (℃)
Vc3: Circulation cooling system capacity (L) in the cooling system configuration in state 3

  When the cooling system circulation path is switched depending on the state, even if the amount of heat received from the engine 101 and the amount of heat released from the radiator 202 are the same, the ultimate water temperature varies depending on the capacity of the circulation path. For this reason, even if it is attempted to control the water temperature on the basis of the water temperature, the water temperature behavior differs depending on the path state, and accurate control cannot be performed. In the present invention, the control element is not the water temperature but the heat quantity of the cooling system. Therefore, if the amount of heat received and radiated is managed in any cooling system path, the amount of heat of the entire cooling system can be grasped, and the control water temperature can be managed.

  In the above, the cooling system control method and the configuration of the cooling water circulation have been described. From this, the control method of the water pump 201, the thermo valve 206, and the passage switching valve 210 when the above-described control states (states (1) to (3)) are switched will be described. FIG. 7 is a diagram showing an example of these control methods, and the horizontal axis is time. (A) has shown the change of the water temperature of a warming-up process. (B) is the rotation speed of the water pump 201. For convenience of explanation, the rotation speed is constant regardless of the water temperature. (C) shows the change in the opening degree of the thermo valve 206, and (d) shows the change in the opening degree of the passage switching valve 210. Further, reference numerals 316 to 318 in FIG. 3 show a control block diagram for performing this control, and this control will be described with reference to FIG. 7 and FIG.

  The time axis t0 to t1 in FIG. 7 is the state (1) described above immediately after the start of the cold machine, where the water temperature is T1 ° C. or lower. The water pump 201 is driven at a predetermined rotational speed in order to circulate the cooling water. The opening degree of the thermo valve 206 and the passage switching valve 210 at this time is as shown in FIG. 4, the opening degree of the thermo valve is fully closed (there is no circulation between the radiator and the engine), and the switching valve 210 is also fully closed. At this time, in 316 of FIG. 3, since the actual water temperature is low, the target switching valve opening is set to be fully closed.

  At time t1 in FIG. 7, the water temperature becomes T1 ° C. in the configuration of the state (1), so the control is changed to the control of the state (2) shown in FIG. The switching method will be described. When the water temperature detects the threshold value T1 ° C. at time t1, first, the rotation of the water pump 201 is decelerated. At this time, in 317 of FIG. 3, when the actual water temperature ≧ T1 ° C. is detected, the target pump rotational speed is decreased, and the pump rotational speed is decelerated by the pump rotational speed driving means (not shown). In FIG. 7, after the rotation of the water pump 201 is stopped, the passage switching valve 210 is driven from fully closed to fully opened (time t2). At this time, in 318 of FIG. 3, after the pump rotational speed is detected and the pump rotational speed becomes 0, the opening degree of the switching valve is changed by the switching valve driving means. In FIG. 7, after detecting that the passage switching valve 210 is fully opened, at a time t3, the water pump 201 is driven again to a predetermined water pump speed. At this time, at 317 in FIG. 3, the target pump speed is changed after detecting that the switching valve opening is fully open, and the pump speed is increased by a pump speed driving means (not shown). In FIG. 7, thereafter, the warm-up operation is continued in the state 2.

  At time t4, since the water temperature is T2 ° C. in the configuration of the state (2), the control is changed to the control of the state (3) shown in FIG. In the state (3), the valve opening of the thermo 206 is adjusted so that the target water temperature is reached. In order to perform feedback control, the thermo valve opening is repeatedly opened and closed in the figure. However, even when the opening change amount of the thermo valve 206 is large, the opening degree of the passage switching valve 210 is also changed. The valve opening degree is changed after the water pump rotation speed is reduced to reduce the circulation of the cooling water.

  In the present embodiment, the control of the cooling system is managed by the amount of heat, and the total amount of heat of the cooling system is determined by the amount of heat of the cooling system stored by the engine cooling system and the amount of heat released from the engine according to the operating state. Since it was made to guess, the heat quantity of the cooling water which changes with the circulating water quantity of a cooling system can be managed, and a precise water temperature control can be performed.

  In addition, because the target heat dissipation amount of the radiator is determined from the total heat amount of the cooling system and the target cooling system total heat amount calculated from the target water temperature determined by the engine operating state, even if the circulating water amount of the cooling system changes The followability to the target water temperature can be improved.

  In addition, it has a radiator wind speed calculating means for calculating the radiator passing wind speed from the vehicle speed and the radiator fan rotation speed, and has a target radiator flow rate calculating means for calculating a target radiator flow rate for realizing a target heat dissipation amount in the radiator. Since the radiator flow rate can be appropriately set according to the circulating water amount of the cooling system, the followability to the target water temperature can be improved.

  Also, a thermo valve control means for calculating the target opening of the thermo valve based on the target radiator flow rate and the water pump flow rate and controlling the thermo valve so as to reach the target opening amount, and feedback control of the thermo valve with respect to the target radiator heat dissipation amount Target radiator heat dissipation feedback means is provided so that it can respond to changing conditions such as changes in cooling water concentration (specific heat), changes in filling amount due to replenishment of cooling water, aging, engine differences, etc. And can respond flexibly.

Embodiment 2. FIG.
In the first embodiment, the water pump 201 is temporarily stopped at the time of switching from the state (1) to the state (2), and then the opening degree of the passage switching valve 210 is changed. However, the water pump 201 is not stopped. In addition, switching may be performed after decelerating to a predetermined rotational speed. In the first embodiment, the change from the closing side to the opening side of the valve has been described as an example. However, the same control can be performed for the change from the opening side to the closing side. Further, the degree of deceleration of the water pump may be changed between the open side and the closed side.

  In the present embodiment, when the target opening change amount of the thermo valve at a predetermined time is not less than a predetermined amount, or when the target passage area change amount at the passage area adjusting means at a predetermined time is not less than a predetermined amount. After the target opening or target passage area has changed, the rotational speed of the water pump is decelerated or stopped, and then the thermo valve opening or passage area is changed. Changes can be avoided, and the durability of the cooling system is improved.

  In addition, since the water pump rotation speed is increased after changing the thermo valve opening or passage area, sudden changes in the circulating water volume in the cooling path can be avoided, and the durability of the cooling system is improved. It is to improve.

Embodiment 3 FIG.
In the first and second embodiments, when the state (1) is switched to the state (2), the water pump 201 is temporarily stopped or decelerated to reduce the circulation of the cooling water, and then the opening degree of the switching valve is changed. However, the following method may be used.

  In FIG. 8, the horizontal axis of the graph and the items indicated by (a) to (d) are the same as those in FIG. The water temperature shows the change in the warm-up process after the start. The water pump rotation speed is constant rotation for convenience of explanation. The time axis t0 to t1 is the state (1) in which the water temperature is equal to or lower than the predetermined value T1 ° C., and the cooling system is configured as shown in FIG. 4, and the thermo valve 206 is fully closed (no recirculation between the engine 101 and the radiator 202 ), The passage switching valve 210 is fully closed.

  Since the water temperature in the configuration of the state (1) becomes the predetermined value T1 on the time axis t1, switching to the state (2) is performed. In the state (2), the opening degree of the passage switching valve 210 is fully opened. However, instead of changing from fully closed to full opening at once, a limit value (Δθ) is provided for the opening change amount for a predetermined time, and the bypass passage 205 is opened. Avoid sudden changes in the amount of water flowing through Thereafter, warm-up is continued with the cooling system configuration in the state (2). As described above, the limit value of the opening change amount can be set from the opening side to the closing side of the valve.

  When the water temperature reaches a predetermined value T2 that is a threshold value in the state (2) on the time axis t2, switching to the state (3) shown in FIG. 6 is performed. In the state (3), the thermo valve opening is adjusted so that the target water temperature is reached. In order to perform feedback control, the thermo valve opening is repeatedly opened and closed in the figure. However, even when the opening change amount of the thermo valve 206 is large, the opening degree of the passage switching valve 210 is also changed. A limit value is provided for the amount of change in the opening, and the valve opening is changed so that the circulation path of the cooling water does not change abruptly.

  In the second embodiment, in order to prevent water hammer generated when the passage switching valve 210 is switched, the number of rotations of the water pump 201 is once reduced and then the passage is switched. By limiting the opening change of the passage switching valve 210, it is possible to prevent a water hammer by reducing a sudden change in the amount of water without reducing the rotational speed of the water pump 201.

  In the present embodiment, when the target opening change amount of the thermo valve at a predetermined time is not less than a predetermined amount, or when the target passage area change amount at the passage area adjusting means at a predetermined time is not less than a predetermined amount. Since the change in the valve opening is limited after the target opening or the target passage area has changed, sudden changes in the circulating water volume in the cooling path can be avoided, and the durability of the cooling system Is to improve.

  The present invention can be applied to a liquid cooling type cooling device for a vehicle power source.

It is a schematic sectional drawing which shows the vehicle drive source (engine) main body which concerns on this invention. It is a figure which shows the structure of the engine cooling system which concerns on Embodiment 1 of this invention. It is a block diagram which shows the control method of the engine cooling system which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the operation | movement aspect of the engine cooling system which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the operation | movement aspect of the engine cooling system which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the operation | movement aspect of the engine cooling system which concerns on Embodiment 1 of this invention. It is a figure which shows the control method at the time of changing the state of the engine cooling system which concerns on Embodiment 1 of this invention with a graph. It is a figure which shows the control method at the time of changing the state of the engine cooling system which concerns on Embodiment 2 of this invention with a graph.

Explanation of symbols

101 engine, 102 throttle valve,
103 crank angle sensor, 104 fuel control valve,
105 ignition control means, 106 electronic control device,
201 water pump, 202 radiator,
203 radiator upper hose, 204 radiator lower hose,
205 bypass passage, 206 thermo valve,
207 heater core, 208 heater in hose,
209 Heater out hose, 210 passage switching valve,
211 water temperature sensor, 212 radiator fan,
213 Radiator fan control device.

Claims (6)

A vehicle power source rotation speed detecting means for detecting a rotation speed of a rotating shaft attached to the vehicle power source and rotating in synchronization with the vehicle power source, and a detection signal from the rotation speed detection means. Vehicle power source rotation speed calculation means for calculating the rotation speed, a water temperature sensor for detecting the cooling water temperature of the vehicle power source, vehicle speed calculation means for calculating the vehicle speed by detecting the rotation speed proportional to the tire axis of the vehicle, A water pump that is attached to the cooling water path of the vehicle power source and circulates the cooling water, a water pump flow rate calculating means that calculates a discharge flow rate of the water pump based on the rotation speed of the water pump, and a cooling water A radiator for exchanging heat, a radiator fan for adjusting the wind speed passing through the radiator, and a radiator fan system for adjusting the wind speed of the radiator fan A heater core for exchanging heat with cooling water to adjust the vehicle interior temperature of the vehicle, and cooling water output from the cooling water outlet of the vehicle power source without passing through the radiator. A bypass passage that circulates to the cooling water inlet, and an adjustment valve that adjusts the diversion flow rate by changing the opening area of the passage to divert the cooling water outlet flow rate of the vehicle power source to the radiator side and the bypass side When, with the passage area adjusting means for adjusting the passage area of the cooling water passage is attached to the cooling water passage, and an electronic control device for controlling the regulating valve and the passage area adjusting means, the vehicle power The total amount of heat in the cooling system is estimated by the amount of cooling system heat stored in the cooling system of the source and the amount of heat released from the vehicle power source according to the driving state, and the total amount of heat in the cooling system, Serial based on the target cooling system the total amount of heat which is calculated by the target water temperature determined by the operating conditions of the vehicle power source, the vehicle being characterized in that to perform the cooling system control by determining a target heat radiation amount in the radiator Power source cooling system control method. Radiator wind speed calculation means for calculating the radiator passing wind speed from the vehicle speed of the vehicle and the rotation speed of the radiator fan, and for achieving the target heat dissipation amount in the radiator from the wind speed of the radiator and the discharge flow rate of the water pump. 2. The vehicle power source cooling system control method according to claim 1, further comprising target radiator flow rate calculation means for calculating a target radiator flow rate. A control valve control means for calculating a target opening of the control valve based on the target radiator flow rate and the discharge flow rate of the water pump, and controlling the control valve so as to reach the target opening; 3. The vehicle power source cooling system control method according to claim 2, further comprising target radiator heat radiation amount feedback means for feedback control of the regulating valve. When the target opening change amount of the adjusting valve at a predetermined time is not less than a predetermined amount, or when the target passage area change amount at the passage area adjusting means at a predetermined time is not less than a predetermined amount, the water pump is rotated. The vehicle power according to any one of claims 1 to 3, wherein the speed is decelerated or stopped, and then the adjustment valve opening or the passage area of the passage area adjusting means is changed. Source cooling system control method. 5. The cooling of a vehicle power source according to claim 4, wherein the speed of the water pump is increased after the opening of the adjusting valve or the passage area of the passage area adjusting means is changed. System control method. When the target opening change amount of the adjusting valve at a predetermined time is not less than a predetermined amount, or when the target passage area change amount of the passage area adjusting means at a predetermined time is not less than a predetermined amount, the adjusting valve or the passage The vehicle power source cooling system control method according to any one of claims 1 to 4, wherein the amount of change in the valve opening of the area adjusting means is limited.

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