JP2011111910A - Engine cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine cooling device stable in control of warming-up operation and giving no influence to an engine even in circulation of cooling water when receiving a request of a circulation flow rate from a heat exchanging means while operating the engine for warming-up without circulating the cooling water. <P>SOLUTION: The engine cooling device 1 includes: a cooling part 2 formed in the engine for flowing of the cooling water; a cooling water temperature sensor part 3 detecting water temperature T of the cooling water; the heat exchanging means 4 using heat possessed by the cooling water; a circulation flow rate varying means 5 varying a circulation flow rate Qc of the cooling water; a circulation water path 6; and a control means 7 regulating the circulation flow rate Qc by controlling the circulation flow rate varying means while referring to the water temperature T upon receipt of a request for a requested flow rate Qr from the heat exchanging means 4. The control means 7 determines a condition of engine warming-up operation according to the water temperature T, performs the warming-up operation without circulating the cooling water by controlling the circulation flow rate varying means, and increases the circulation flow rate Qc to the requested flow rate Qr for a predetermined period of time when receiving the request of the requested flow rate Qr during the warming-up operation. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cooling apparatus that circulates cooling water to cool an engine, and more particularly to an engine cooling apparatus that includes a heat exchange means that uses heat of cooling water.

  2. Description of the Related Art A water-cooled cooling device that cools an engine by forcibly circulating cooling water is widely used for an engine mounted on a vehicle. For circulating the cooling water, a mechanical water pump driven by an engine crankshaft or an electric water pump driven by electric power supplied from a vehicle-mounted battery is generally used. In this type of cooling device, when the engine is warmed up, the cooling water is made efficient without circulating the cooling water until a constant water temperature is reached, and an example thereof is disclosed in Patent Document 1. .

  In the water pump control device for an internal combustion engine of Patent Document 1, an electric motor is attached to a cooling water circulation water pump, and the control means controls the electric motor according to a cooling water temperature detected by a temperature sensor arranged near the cooling water outlet. A configuration is disclosed. When the cooling water temperature is equal to or lower than the normal start lower limit water temperature, the water pump is stopped. When the cooling water temperature is lower than the normal start lower limit water temperature and equal to or lower than the warm-up promotion upper limit water temperature, the water pump is rotated at high speed. As a result, it is said that the starter cranking time and the time to self-running are shortened by stopping the water pump, and the entire engine is warmed up quickly by the high speed rotation of the water pump, enabling smooth engine operation. Yes.

  Further, the cooling device for an internal combustion engine of Patent Document 2 includes a water level detection means provided in a part of the cooling water conduit and a boiling detection means for detecting boiling of the cooling water based on the rising rate of the water level. Is disclosed. The boiling detection based on the water level has a faster response than the boiling detection based on the temperature, and the difference is particularly noticeable when the water pump is stopped especially during warm-up operation. Furthermore, it is described that when the water pump is stopped, boiling of the cooling water can be detected quickly, and the flow rate of the cooling water can be increased to lower the water temperature. That is, the reliability when warming up by stopping the water pump is increased.

  On the other hand, the heat of cooling water is widely used for heating and defrosting in a vehicle, which is preferable from the viewpoint of effective use of energy. For example, the embodiment of Patent Document 1 discloses a mode in which a heating air conditioner is provided separately from a radiator that dissipates heat of the cooling water, and the heating air conditioner uses a part of the cooling water as a heat source. .

JP-A-8-14043 JP 2008-303775 A

  By the way, if the engine is warmed up without circulating cooling water in a cooling device combined with heat exchange means such as a heating air conditioner, and a request for the circulation flow rate is received from the heat exchange means, There is a concern that inconvenience occurs when the cooling water is circulated. More specifically, the warm-up operation conditions when the engine is warmed-up, such as the idling speed, the fuel injection amount, the ignition timing, etc., are determined and controlled according to the coolant temperature. However, the temperature of the cooling water is generally detected at one point of the cooling water temperature sensor located at the outlet of the engine cooling unit. When the circulation is started, first the high-temperature cooling water in the engine and then the engine Outside low-temperature cooling water flows to the sensor unit. Therefore, fluctuations in the detected water temperature become large, the warm-up operation conditions are not stabilized, and it becomes difficult to control the warm-up operation. In particular, when the required flow rate is circulated suddenly in a state where the warm-up operation has progressed to a certain extent, the detected water temperature fluctuates greatly, which may affect the engine. As a countermeasure, if the warm-up operation is performed while circulating the cooling water, the fluctuation of the water temperature can be reduced, but the efficiency of the warm-up operation is reduced by the amount of heat dissipated from the cooling water by the circulation.

  The present invention has been made in view of the above problems, and when the engine is warmed up without circulating the cooling water and a request for the circulation flow rate is received from the heat exchange means, the cooling water is circulated. It is an object of the present invention to provide an engine cooling device that stabilizes warm-up operation control and does not affect the engine.

The invention of the engine cooling device according to claim 1 that solves the above-described problems includes a cooling unit that is formed in the engine and through which cooling water flows, a cooling water temperature sensor that detects a temperature of the cooling water, and the cooling water. Exchanging heat, means for changing the circulating flow rate of the cooling water, variable cooling means for changing the circulating flow rate, cooling unit, temperature sensor for cooling water, heat exchanging means, and variable circulating flow rate means A circulation channel through which the cooling water flows, and a control unit that receives the request for the required flow rate from the heat exchange unit and controls the circulation flow rate variable unit while referring to the water temperature to adjust the circulation flow rate. An engine cooling device comprising:
The control means determines a warm-up operation condition when warming up the engine according to the water temperature, and controls the circulation flow rate variable means to warm up the engine without circulating the cooling water. When the request for the required flow rate is received during the warm-up operation, the circulating flow rate is increased to the required flow rate over a predetermined time.

  The invention according to claim 2 is characterized in that, in claim 1, the control means increases the circulating flow rate stepwise.

  According to a third aspect of the present invention, in the first aspect, the control means increases the circulation flow rate in proportion to an elapsed time.

  The invention according to claim 4 is characterized in that, in claim 1, the control means increases the circulating flow rate in accordance with characteristics of a first-order lag filter.

  The invention according to claim 5 is characterized in that, in claim 1, the control means adjusts the circulation flow rate while performing feedback control so as to limit fluctuations in the water temperature.

  The invention of the engine cooling device according to claim 6 utilizes a cooling part formed in the engine through which cooling water flows, a cooling water temperature sensor part for detecting a temperature of the cooling water, and heat of the cooling water. Circulates through the heat exchanging means, the circulating flow rate varying means for varying the circulating flow rate of the cooling water, the cooling unit, the cooling water temperature sensor unit, the heat exchanging unit, and the circulating flow rate varying unit, An engine comprising: a circulating water channel through which cooling water flows; and a control unit that receives a request for a required flow rate from the heat exchange unit and controls the circulating flow rate variable unit while adjusting the circulating flow rate while referring to the water temperature. In the cooling device, the control means determines a warm-up operation condition when the engine is warm-up according to the water temperature, and controls the circulation flow rate variable means to circulate the cooling water without circulating the cooling water. Warm up the engine In response to a request for the required flow rate during warm-up operation, the circulating flow rate is immediately increased to the required flow rate, and after that, the water temperature is subjected to a filtering process to obtain a gently changing correction water temperature. And determining the warm-up operation conditions.

  The invention according to claim 7 is the electronic water pump according to any one of claims 1 to 6, wherein the circulating flow rate varying means is a variable flow type electric water pump, or a mechanical water pump driven by the engine and a flow rate adjustment. It is a valve.

  According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the circulating flow rate varying means is an electric water pump having a variable flow rate, and the cooling water feeling is provided at an outlet of the cooling unit of the engine. A temperature sensor unit is disposed, an outlet of the electric water pump is connected to an inlet of the cooling unit, and the temperature sensor unit is diverted from the circulation water channel between the cooling water temperature sensor unit and the heat exchange unit, and It is characterized by comprising a radiating water channel that joins the circulating water channel at the suction port of an electric water pump, and a radiator and a thermostat valve provided in the radiating water channel.

  The invention according to claim 9 is characterized in that, in any one of claims 1 to 8, the engine is mounted on a vehicle, and the heat exchange means is a heating device or a defroster.

  The engine cooling device according to claim 1 includes an engine cooling unit, a cooling water temperature sensor unit, a heat exchange unit, a circulation flow rate varying unit, a circulation channel, and a control unit. The warm-up operation conditions are determined when the engine is warmed up, and the engine is warmed up without circulating the cooling water by controlling the circulating flow rate variable means. When the request is received, the circulating flow rate is increased to the required flow rate over a predetermined time. That is, after receiving the request, the cooling water starts to flow at a circulation flow rate smaller than the required flow rate. Thereby, the cooling water outside the engine which has not been warmed by the warm-up operation slowly passes through the cooling part of the engine and reaches the cooling water temperature sensor part after being warmed. On the other hand, in the conventional apparatus that suddenly controls the circulation flow rate to the required flow rate, the cooling water outside the engine flows too quickly through the cooling part of the engine, so that it is not warmed very much. Therefore, according to the present invention, the temperature difference between the cooling water that has been warmed in the engine from the beginning and the cooling water that has been outside the engine and that has been warmed by passing through the cooling section of the engine is smaller than before, and the cooling water feeling is reduced. The fluctuation of the water temperature detected by the temperature sensor is reduced, the control of the warm-up operation is stabilized, and the engine is not affected.

  In the invention according to claim 2, the control means increases the circulation flow rate stepwise. In the invention according to claim 3, the control means increases the circulation flow rate in proportion to the elapsed time. Further, in the invention according to claim 4, the control means increases the circulating flow rate according to the characteristics of the first-order lag filter. In the inventions according to claims 2 to 4, after receiving the request for the required flow rate from the heat exchange means, the cooling water starts flowing at a circulating flow rate less than the required flow rate, and increases to the required flow rate over a predetermined time. Actions and effects similar to those of the first aspect are produced.

  In the invention which concerns on Claim 5, a control means adjusts a circulating flow volume, performing feedback control so that the fluctuation | variation of water temperature may be restrict | limited. Therefore, the fluctuation of the water temperature can be surely limited within a range that does not affect the control of the warm-up operation, and the circulation flow rate can be quickly increased within the possible range to meet the demand from the heat exchange means.

  The invention of the engine cooling device according to claim 6 comprises an engine cooling section, a cooling water temperature sensor section, a heat exchanging means, a circulating flow rate varying means, a circulating water channel, and a control means, the control means depending on the water temperature. The warm-up operation conditions are determined when the engine is warmed up, and the engine is warmed up without circulating the cooling water by controlling the circulating flow rate variable means. When the request is received, the circulation flow rate is immediately increased to the required flow rate, and thereafter, the warming-up operation condition is determined according to the corrected water temperature which is obtained by performing a filtering process on the water temperature. In other words, after the start of the circulation of the cooling water, the warm-up operation condition is determined according to the corrected water temperature that changes more gently than the actually detected water temperature, so that the control of the warm-up operation is not affected. Further, by immediately increasing the circulation flow rate to the required flow rate, it is possible to meet the demand from the heat exchange means.

  In the invention according to claim 7, an electric water pump with variable flow rate, or a mechanical water pump and a flow rate adjusting valve driven by an engine can be used as the circulating flow rate varying means. The present invention is not limited to the type and structure of the water pump, and has a wide range of applications.

  According to an eighth aspect of the present invention, an electric water pump having a variable flow rate is used as the circulating flow rate varying means, and a heat radiating water channel is formed that diverts from the circulating water channel and merges with the circulating water channel through the radiator and the thermostat valve. Here, the thermostat valve automatically adjusts the opening according to the coolant temperature, and as the coolant temperature rises, the flow rate of the radiating water passage increases and the amount of heat released from the radiator increases. Thereby, the structure which discharge | releases the heat which a cooling water preferentially with a heat exchange means, and can heat | radiate the surplus which cannot be discharged | emitted with a radiator is realizable. The present invention can be realized in various modes such as a configuration in which heat is radiated only by heat exchange means, a configuration in which heat is radiated preferentially by heat exchange means, and a surplus is radiated by a radiator, and a configuration in which heat exchange means and a radiator are used in combination.

  In the invention according to claim 9, the engine is mounted on the vehicle, and the heat exchange means is a heating device or a defroster. The present invention is suitable for a cooling device that cools an in-vehicle engine.

It is a whole lineblock diagram explaining the engine cooling device of a 1st embodiment typically. In 1st Embodiment, it is a figure explaining the control method which increases circulating flow volume over predetermined time in engine control ECU. In 1st Embodiment, it is a figure of the cooling water control flow at the time of engine warming-up operation by engine control ECU. In 1st Embodiment, it is a figure explaining the effect when circulating flow volume is increased over predetermined time based on FIG. In 1st Embodiment, it is a figure explaining another control method which increases a circulation flow rate in proportion to elapsed time in engine control ECU. In 1st Embodiment, it is a figure explaining another control method which increases circulation flow volume according to the characteristic of a primary delay filter in engine control ECU. It is a figure of the cooling water control flow at the time of engine warming-up operation by engine control ECU in 2nd Embodiment. In 3rd Embodiment, it is a figure explaining the effect which performs a filter process to the water temperature of cooling water, and calculates | requires correction | amendment water temperature.

  An engine cooling apparatus according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall configuration diagram schematically illustrating an engine cooling device 1 according to a first embodiment. The cooling device 1 according to the embodiment cools an in-vehicle engine and heats the inside of the vehicle using heat of cooling water. The cooling device 1 includes a water jacket 2, a cooling water temperature sensor unit 3, a heating device 4, an electric water pump 5, a circulating water channel 6, an engine control ECU 7, a radiating water channel 81, a radiator 82, a thermostat valve 83, and the like. Yes.

  The water jacket 2 is a part corresponding to the cooling part of the engine. The water jacket 2 is formed so as to surround a cylinder of an unillustrated engine so that cooling water flows inside. At the outlet 21 of the water jacket 2, the cooling water temperature sensor unit 3 that detects the coolant temperature T is disposed. The heating device 4 is a part corresponding to heat exchange means. The heating device 4 includes a heater core 41 (corresponding to the heat exchanger main body) that takes in the heat of the cooling water, a control unit 42 that controls the operation of the heater core 41, and the like. The electric water pump 5 is a circulation flow rate variable means that makes the circulation flow rate Qc variable by controlling input power. As the electric water pump 5, a general vane pump, a centrifugal pump, or the like can be used. The discharge port 51 of the electric water pump 5 is connected to the inlet 22 of the water jacket 2.

  The circulating water channel 6 is a water channel through which the cooling water flows so as to circulate through the water jacket 2, the cooling water temperature sensor unit 3, the heater core 41 of the heating device 4, and the electric water pump 5. In FIG. 1, the flow of the cooling water is indicated by an arrow F. The circulating water channel 6 includes a first water channel 61 that connects the cooling water temperature sensor 3 and the inlet 411 of the heater core 41, and a second water channel 62 that connects the outlet 412 of the heater core 41 and the junction 63. ing. The merge part 63 is a part where a later-described facility water channel 81 merges. The junction 63 is connected to the suction port 52 of the electric water pump 5.

  On the other hand, the radiating water channel 81 is a water channel that is diverted from the first water channel 61 in the circulating water channel 6, passes through the radiator 82, and is connected to the thermostat valve 83. When viewed from the electric water pump 5, the heater core 41 and the radiator 82 of the heating device 4 are arranged in parallel. The radiator 82 has an internal water channel, and the cooling water dissipates heat by passing through the internal water channel. The thermostat valve 83 is a valve that automatically adjusts the opening according to the coolant temperature. An outlet 831 having a variable opening degree of the thermostat valve 83 opens to the merging portion 63, and an unillustrated temperature sensing portion of the thermostat valve 83 is disposed in the merging portion 63. The thermostat valve 83 is in a closed state at a low water temperature when the engine is warming up, and automatically opens when the engine operates and the water temperature rises to flow cooling water through the radiating water channel 81, and heat is dissipated by the radiator 82. Is to be done. In addition, a reservoir tank 84 is provided connected to the radiating water channel 81 and the radiator 82 to absorb the change in the coolant level due to the temperature change and to compensate for the lack of the coolant.

  The engine control ECU 7 is an electronic control unit that controls the operation of the engine, and is a part corresponding to a control unit that adjusts the circulating flow rate Qc of the cooling water. The engine control ECU 7 receives the cooling water temperature T from the cooling water temperature sensor 3 and receives the required flow rate Qr required for heating from the control unit 42 of the heating device 4. The engine control ECU 7 controls the input power supplied to the electric water pump 5 to adjust the circulation flow rate Qc. Furthermore, the engine control ECU 7 determines and controls engine operating conditions according to the water temperature T. Specific control amounts controlled by the engine control ECU 7 include engine speed, fuel injection amount, ignition timing, and the like.

  Further, the engine control ECU 7 determines a warm-up operation condition according to the water temperature T, and controls the electric water pump 5 so as not to circulate the cooling water, that is, sets the circulation flow rate Qc = 0 to warm-up the engine ( Water stop warm-up). When the water temperature T reaches a predetermined value, the engine control ECU 7 controls the electric water pump 5 to circulate the cooling water, and continues the warm-up operation so that the entire system including the circulation water path 6 is warmed (water circulation warming). Machine). When the engine control ECU 7 receives a request for the required flow rate Qr from the control unit 42 of the heating device 4 during the water stop warm-up operation with the circulation flow rate Qc = 0, the engine control ECU 7 takes the predetermined time to reduce the circulation flow rate Qc to the required flow rate Qr. The electric water pump 5 is controlled so as to increase. The engine control ECU 7 has a timer for measuring the elapsed time tx from the request time t1 when the request for the required flow rate Qr is received.

  FIG. 2 is a diagram for explaining a control method in which the engine control ECU 7 increases the circulation flow rate Qc over a predetermined time. In FIG. 2, the horizontal axis represents time t, the vertical axis represents the flow rate Q, the broken line graph represents the required flow rate Qr, and the solid line graph represents the circulation flow rate Qc. The graph illustrates a case where a request for the required flow rate Qr is received at the required time t1 during the water stop warm-up operation with the circulation flow rate Qc = 0. As shown in the figure, the engine control ECU 7 does not immediately increase the circulation flow rate Qc to the required flow rate Qr at the required time t1, but increases it to a reduced flow rate Qd smaller than the required flow rate Qr. Thereafter, at the time t2 when the elapsed time tx reaches the predetermined time tr, the circulating flow rate Qc is increased from the reduced flow rate Qd to the required flow rate Qr. That is, the engine control ECU 7 increases the circulation flow rate Qc stepwise as a transition process when increasing the circulation flow rate Qc to the required flow rate Qr. However, when the required flow rate Qr is as small as the constant flow rate Q0 or less, the engine warm-up operation is continued with the circulation flow rate Qc = 0.

  Note that the reduced flow rate Qd, the predetermined time tr, and the constant flow rate Q0 may be fixed amounts, but it is preferable to set the amount of change that can be changed according to the water temperature T and the required flow rate Qr at that time. In order to reduce the fluctuation of the water temperature T, it is preferable to reduce the reduced flow rate Qd, increase the predetermined time tr, and set the constant dragon amount Q0 to be large, but on the other hand, it does not meet the request from the heating device 4. Therefore, the start-up of the heating device 4 is delayed. Accordingly, an appropriate reduced flow rate Qd that allows the heating device 4 to be quickly started up while limiting the fluctuation of the water temperature T to a certain amount or less so as not to affect the control of the warm-up operation of the engine, the predetermined time tr, And a constant flow Q0. These appropriate values can be obtained, for example, by experiments performed by changing various conditions, and can be stored as a map in the engine control ECU 7.

  Next, the operation of the engine cooling apparatus 1 of the first embodiment configured as described above will be described with reference to FIG. FIG. 3 is a flowchart of a coolant control flow during engine warm-up operation by the engine control ECU 7. As shown in the figure, when the warm-up operation is started in step S1, the engine control ECU 7 determines in step S2 whether the water stop warm-up or the water circulation warm-up is in progress. Then, the process proceeds to step S8 when the water circulation is warming up, and the presence or absence of the required flow rate Qr from the heating device is determined at step 3 when the water stop is warming up. When the requested flow rate Qr is not present, the process proceeds to step S7. When the requested flow rate Qr is received for the first time, the timer is started and the elapsed time tx is started. Then, the process proceeds to step S4, and the requested flow rate Qr is continued. Also proceeds to step S4.

  Next, in step 4, it is determined whether the required flow rate Qr exceeds a certain flow rate Q0. When the required flow rate Qr does not exceed the constant flow rate Q0, the process proceeds to step S7. When the required flow rate Qr exceeds the predetermined flow rate Q0, it is determined in step S5 whether the elapsed time tx measured by the timer is equal to or longer than the predetermined time tr. When the elapsed time tx is equal to or longer than the predetermined time tr, the process proceeds to step S8, and when the elapsed time tx is less than the predetermined time tr, the process proceeds to step S6. Thus, one of the steps S6 to S8 is finally reached.

  When the conditions for reaching Step S6 are arranged, it is when the required flow rate Qr exceeding the constant flow rate Q0 is received during the water stop warm-up and the elapsed time tx is less than the constant time tr. At this time, the engine control ECU 7 controls the electric water pump 5 so that the circulation flow rate Qc becomes the reduced flow rate Qd. When the conditions for reaching step S7 are arranged, it is when the water stop is warming up and the required flow rate Qr is zero or less than the constant flow rate Q0. At this time, the engine control ECU 7 controls the circulation flow rate Qc = 0 to continue the water stop warm-up. The conditions for reaching step S8 are arranged when the water circulation is warming up and when the required flow rate Qr exceeds the constant flow rate Q0 and the elapsed time tx is equal to or longer than the predetermined time tr. The latter condition means after the transition processing for a certain time tr with the reduced flow rate Qd is completed. At this time, the engine control ECU 7 performs normal water circulation warm-up control. In other words, the circulation flow rate Qc is controlled so as to immediately respond to the change in the required flow rate Qr.

  Since one cycle of control is completed by any one of steps S6 to S8, the process returns to step S2, and thereafter the same control is repeated.

  Next, the operation and effect of the engine cooling device 1 of the first embodiment will be described with reference to FIG. FIG. 4 is a diagram for explaining the effect when the circulation flow rate Qc is increased over a predetermined time based on FIG. In FIG. 4, the horizontal axis is time t, and the vertical axis is the coolant temperature T detected by the coolant temperature sensor 3. FIG. 4 illustrates a case where the warm-up operation of the engine is started at the warm-up start time t0 and the request for the required flow rate Qr is received at the request time t1. A solid graph 1 in the figure shows a change in the coolant temperature T when the circulating flow rate Qc is increased stepwise from the water stop warm-up to the required flow rate Qr through the reduced flow rate Qd based on FIG. Yes. A broken line graph 2 shows a change in the coolant temperature T when using the conventional control method in which the required flow rate Qr is immediately increased from the water stop warm-up to the required flow rate Q1. In addition, a dashed-dotted line graph 3 shows a change in the coolant temperature T when the conventional control method for circulating the coolant from the warm-up operation start time t0 is used.

  First, comparing the graph 1 and the graph 2 with the graph 3, the effect of the water stop warm-up without circulating the cooling water will be described. In graphs 1 and 2 in which the water stop warm-up is performed, the water temperature T increases sharply immediately after the warm-up operation start time t0, compared to the graph 3 in which the conventional water stop warm-up is not performed. This indicates that the inside of the engine including the piston is quickly warmed up.

  Next, the effect of increasing the circulation flow rate Qc stepwise will be described by comparing the graph 1 with the graph 2. In graph 2, the engine control ECU 7 immediately increases the circulation flow rate Qc to the required flow rate Qr at the required time t1. For this reason, while the cooling water heated in the engine water jacket 2 from the beginning flows, the water temperature T rises to P1 in the figure, but the cooling water in the second water passage 62 outside the engine is the cooling water. When flowing through the temperature sensor 3, the water temperature T drops to P2 in the figure, and the temperature fluctuates greatly. For this reason, it becomes difficult for the engine control ECU 7 to set a stable warm-up operation condition according to the water temperature T, and it becomes difficult to control the warm-up operation, which may affect the engine.

  On the other hand, in the graph 1, the engine control ECU 7 increases the circulation flow rate Qc to the reduced flow rate Qd immediately after the request time t1. For this reason, the cooling water in the second water passage 62 outside the engine passes through the water jacket 2 and is warmed up, and then reaches the cooling water temperature sensor 3. Therefore, as shown in the figure, the fluctuation of the water temperature T is smaller than that in the graph 2, and stable warm-up operation conditions can be determined, and the engine is not affected.

  In the first embodiment, the reduction flow rate Qd when the circulation flow rate Qc is increased stepwise over a predetermined time tr has been described in one step. However, a plurality of steps are provided to increase the flow rate stepwise. Alternatively, as a method of increasing the circulation flow rate Qc over a predetermined time tr, another method shown in FIGS. 5 and 6 may be used.

  FIG. 5 is a diagram for explaining another control method for increasing the circulation flow rate Qc in proportion to the elapsed time tx in the engine control ECU 7. As shown in the figure, the engine control ECU 7 increases the circulating flow rate Qc with a constant slope immediately after the requested time t1, and turns the electric water pump 5 so as to reach the requested flow rate Qr at a time t3 after a predetermined time tr. Control.

  FIG. 6 is a diagram for explaining another control method for increasing the circulation flow rate Qc in accordance with the characteristics of the first-order lag filter in the engine control ECU 7. As shown in the figure, the engine control ECU 7 increases the circulation flow rate Qc relatively steeply at the beginning according to the characteristics of the first-order lag filter immediately after the request time t1, and gradually decreases the increase amount to approach the request flow rate Qr. The electric water pump 5 is controlled. When the characteristics of the first-order lag filter are used as shown in FIG. 6, the circulating flow rate Qc and the required flow rate Qr are not equal, but both are substantially the same value, in other words, the circulating flow rate Qc is stable. The time required to reach the range of values for obtaining the warm-up operation condition can be defined as the predetermined time.

  In addition, various control methods can be used to reach the required flow rate Qr over a predetermined time.

  Next, an engine cooling apparatus according to a second embodiment that uses feedback control to control the circulating flow rate Qc of the cooling water will be described with reference to FIG. In the second embodiment, the apparatus configuration itself is the same as that of the first embodiment shown in FIG. 1, and the control method of the engine control ECU 7, that is, the software is different. FIG. 7 is a flowchart of a coolant control flow during engine warm-up operation by the engine control ECU 7 in the second embodiment.

  As shown in FIG. 7, when the warm-up operation is started in Step S11, the engine control ECU 7 compares the required flow rate Qr of the heating device 4 at that time with the circulation flow rate Qc in Step S12. And when the request | requirement flow volume Qr is below the circulation flow volume Qc, since the request | requirement of the heating apparatus 4 has already been satisfy | filled, it progresses to step S17 and controls the electric water pump 5 so that the circulation flow volume Qc may be maintained. When the required flow rate Qr exceeds the circulation flow rate Qc, the process proceeds to step S13, and the variation ΔT of the coolant temperature T detected by the coolant temperature sensor 3 is compared with the allowable upper limit value ΔTU. When the fluctuation ΔT exceeds the allowable upper limit ΔTU and is excessive, the process proceeds to step S15 and the electric water pump 5 is controlled so as to decrease the circulation flow rate Qc. Thereby, fluctuation | variation (DELTA) T of the water temperature T can be suppressed.

  When the variation ΔT is less than or equal to the allowable upper limit value ΔTU in step S13, the process proceeds to step S14, where the variation ΔT of the water temperature T is set to an allowable lower limit value ΔTL smaller than the allowable upper limit value ΔTU (that is, ΔTL <ΔTU). Compare with When the fluctuation ΔT is less than the allowable lower limit ΔTU, the process proceeds to step S16 to control the electric water pump 5 so as to increase the circulation flow rate Qc. Thereby, it can respond to the request | requirement from the heating apparatus 4 quickly. Further, when the fluctuation ΔT is equal to or greater than the allowable lower limit ΔTU, the fluctuation ΔT of the water temperature T is properly maintained, so that the process proceeds to step S17 and the electric water pump 5 is set so as to maintain the circulating flow rate Qc. Control. Since one cycle of control is completed by any of steps S15 to S17, the process returns to step S12, and thereafter the same control is repeated.

  According to the cooling water control flow of the second embodiment described above, the fluctuation ΔT of the coolant temperature T falls within the allowable upper limit value ΔTU and the allowable lower limit value ΔTL that do not affect the control of the warm-up operation. Can be reliably restricted. In addition, the circulation flow rate Qc can be quickly increased within a possible range to meet the demand from the heat exchange means 4.

  Next, an engine cooling apparatus according to a third embodiment that corrects the detected water temperature T without adjusting the cooling water circulation flow rate Qc will be described with reference to FIG. In the third embodiment, the apparatus configuration itself is the same as that of the first embodiment shown in FIG. 1, and the control method of the engine control ECU 7, that is, the software is different from that of the first and second embodiments. In the third embodiment, the engine control ECU 7 immediately increases the circulation flow rate Qc to the required flow rate Qr when a request for the required flow rate Qr is received from the heating device 4 during the water stop warm-up operation. Thereafter, the cooling water temperature T detected by the cooling water temperature sensor unit 3 is filtered, and the warming-up operation conditions are determined according to the obtained correction water temperature TA that changes gently.

  FIG. 8 is a diagram for explaining the effect of obtaining the corrected water temperature TA by filtering the water temperature T of the cooling water in the third embodiment. The horizontal axis in the figure is the common time t, the upper graph shows the change in the circulation flow rate Qc, the lower graph shows the change in the water temperature T and the correction water temperature TA, and the request flow rate Qr is requested at the request time t1. In this example, the request flow rate Qr returns to 0 at time t4. As shown in the upper graph, the engine control ECU 7 controls the electric water pump 5 so that the circulation flow rate Qc immediately follows the change in the required flow rate Qr. Further, as shown in the lower graph, the engine control ECU 7 performs a filtering process on the detected water temperature T (solid line) to obtain a corrected water temperature TA (broken line). Then, the engine control ECU 7 determines the warm-up operation condition according to the corrected water temperature TA that changes gradually after the request time t1.

  Therefore, according to the third embodiment, since the warm-up operation condition can be determined according to the corrected water temperature TA that changes more gently than the actually detected water temperature T, the control of the warm-up operation is not affected. . Further, the request from the heating device 4 can be met by immediately increasing the circulation flow rate Qc to the required flow rate Qr at the required time t1.

  In each embodiment, a mechanical water pump and a flow rate adjusting valve may be provided instead of the electric water pump 5. For example, an electrically controllable needle valve is used as the flow rate adjustment valve, and the flow control valve is configured to be controlled by the engine control ECU 7. In this aspect, by controlling the opening degree of the needle valve, the circulation flow rate Qc can be freely adjusted within the range of the discharge amount of the mechanical water pump depending on the engine speed.

  Further, a bypass water channel that immediately returns from the outlet 21 of the water jacket 2 to the junction 63 may be provided to improve the efficiency of the warm-up operation. In addition, the present invention can be applied in various ways.

1: Engine cooling device 2: Water jacket (cooling part) 21: Outlet 22: Inlet 3: Cooling water temperature sensor part 4: Heating device (heat exchange means) 41: Heater core 42: Control unit 5: Electric type Water pump (circulation flow rate varying means) 51: Discharge port 52: Suction port 6: Circulating water channel 61: First water channel 62: Second water channel 63: Merging unit 7: Engine control ECU (control unit)
81: Facility water channel 82: Radiator 83: Thermostat valve Qc: Circulating flow rate Qr: Required flow rate Qd: Reduced flow rate tr: Predetermined time

Claims (9)

A cooling part that is formed in the engine and through which cooling water flows, a cooling water temperature sensor part that detects a temperature of the cooling water, a heat exchange means that uses heat of the cooling water, and a circulating flow rate of the cooling water. A variable circulation flow rate means, a cooling part, a cooling water temperature sensor part, a heat exchange means, a circulation channel through which the circulation water flows through the circulation flow rate variable means, and the heat exchange means A control means for adjusting the circulating flow rate by controlling the circulating flow rate varying means while receiving the request for the required flow rate and referring to the water temperature,
The control means determines a warm-up operation condition when warming up the engine according to the water temperature, and controls the circulation flow rate variable means to warm up the engine without circulating the cooling water. An engine cooling apparatus characterized by increasing the circulating flow rate to the required flow rate over a predetermined time when the request for the required flow rate is received during warm-up operation.   2. The engine cooling apparatus according to claim 1, wherein the control means increases the circulating flow rate stepwise.   2. The engine cooling apparatus according to claim 1, wherein the control means increases the circulation flow rate in proportion to an elapsed time.   2. The engine cooling apparatus according to claim 1, wherein the control means increases the circulating flow rate in accordance with a characteristic of a first-order lag filter.   2. The engine cooling apparatus according to claim 1, wherein the control means adjusts the circulating flow rate while performing feedback control so as to limit fluctuations in the water temperature. A cooling part that is formed in the engine and through which cooling water flows, a cooling water temperature sensor part that detects a temperature of the cooling water, a heat exchange means that uses heat of the cooling water, and a circulating flow rate of the cooling water. A variable circulation flow rate means, a cooling part, a cooling water temperature sensor part, a heat exchange means, a circulation channel through which the circulation water flows through the circulation flow rate variable means, and the heat exchange means A control means for adjusting the circulating flow rate by controlling the circulating flow rate varying means while receiving the request for the required flow rate and referring to the water temperature,
The control means determines a warm-up operation condition when warming up the engine according to the water temperature, and controls the circulation flow rate variable means to warm up the engine without circulating the cooling water. In response to a request for the required flow rate during warm-up operation, the circulation flow rate is immediately increased to the required flow rate, and thereafter, the water temperature is subjected to a filtering process to obtain a gently changing correction water temperature. An engine cooling system characterized by determining a warm-up operation condition.   7. The circulating flow rate varying means according to claim 1, wherein the circulating flow rate varying means is a flow rate variable electric water pump, or a mechanical water pump and a flow rate adjusting valve driven by the engine. Engine cooling system. In any one of Claims 1-7, the said circulating flow rate variable means is an electric water pump of variable flow rate, the said cooling water temperature sensor part is arrange | positioned in the outflow port of the said cooling part of the said engine, The discharge port of the electric water pump is connected to the inlet of the cooling unit,
A radiating water channel that diverts from the circulating water channel between the cooling water temperature sensor unit and the heat exchanging means and merges with the circulating water channel at the suction port of the electric water pump, and is provided in the radiating water channel. An engine cooling apparatus comprising: a radiator and a thermostat valve.   9. The engine cooling device according to claim 1, wherein the engine is mounted on a vehicle, and the heat exchange means is a heating device or a defroster.

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