JP2010007570A - Warm-up control system of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a warm-up control system of an internal combustion engine in which warm-up operation is completed earlier while reducing the thermal damage to an exhaust heat recovering device. <P>SOLUTION: This warm-up control system of the internal combustion engine comprises: an electric pump W/P11 for circulating the cooling water of the engine 10; the exhaust heat recovering device 30 for recovering the exhaust heat by exchanging heat between the engine exhaust gas and the cooling water; a warm-up necessity determination means S20 for determining whether the warm-up operation of the engine 10 is required or not; an engine circulation path J1 for circulating the cooling water in such a manner that the cooling water flows into the engine 10 and the exhaust heat recovering device 30; and a bypass circulation path J2 for circulating the cooling water by bypassing the engine 10 in such a manner that the cooling water flows into the exhaust heat recovering device 30. The operations of solenoid valves V1, V2 are controlled in such a manner that when the warm-up is determined unnecessary, the cooling water is circulated in the engine circulation path J1 and when the warm-up is determined necessary, the cooling water is circulated in the bypass circulation path J2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an internal combustion engine warm-up control system including an exhaust heat recovery device that recovers exhaust heat.

  Conventionally, in order to complete the warm-up operation of the internal combustion engine at an early stage, the following two means are disclosed in Patent Documents 1 and 2 and the like.

That is, in Patent Document 1, the pump that circulates the coolant (engine coolant) of the internal combustion engine is an electric type, and the operation of the electric pump is stopped during the warm-up operation so that the heat exchange with the internal combustion engine (water jacket) ) Engine coolant is stopped to promote a temperature rise, thereby achieving early completion of warm-up operation. Patent Document 2 discloses an exhaust heat recovery device that recovers exhaust heat by exchanging heat between exhaust discharged from an internal combustion engine and engine cooling water. If the engine coolant is heated by the exhaust heat recovery device, the warm-up operation can be completed early.
JP 2004-360509 A JP 2007-24424 A

  Here, the present inventors considered further early completion of the warm-up operation by providing the means for stopping the electric pump during the warm-up operation described above, the means for recovering the exhaust heat, and both means. As a result of the examination, it has been found that the following problems occur when these two means are provided.

  That is, if the electric pump is stopped during the warm-up operation, the circulation of the engine cooling water in the exhaust heat recovery device is also stopped, so that the heat transfer from the high-temperature exhaust to the engine cooling water is delayed. . Then, the exhaust heat recovery device may be damaged by the heat of the high-temperature exhaust.

  The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a warm-up control system for an internal combustion engine that achieves early completion of warm-up operation while reducing thermal damage of the exhaust heat recovery device. Is to provide.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

In invention of Claim 1,
A pump for circulating the coolant of the internal combustion engine;
An exhaust heat recovery unit that recovers exhaust heat by exchanging heat between the exhaust discharged from the internal combustion engine and the coolant;
A warm-up necessity determination unit for determining whether the internal combustion engine requires a warm-up operation;
An engine circulation path for circulating the coolant to flow into the internal combustion engine and the exhaust heat recovery unit;
A bypass circulation path for circulating the coolant to bypass the internal combustion engine and flow into the exhaust heat recovery device;
A switching valve that switches the circulation path to either the engine circulation path or the bypass circulation path;
The operation of the switching valve is controlled so that the engine circulation path is circulated when the warm-up necessity determination unit determines that the warm-up is not required, and the bypass circulation path is circulated when it is determined that the warm-up is necessary. Valve control means;
It is characterized by providing.

  According to this, since the bypass circulation path is circulated when warming-up is required, the coolant in the exhaust heat recovery device is retained while the coolant in the portion (for example, in the water jacket) where heat exchange with the internal combustion engine is stopped. It can be circulated. Therefore, by stopping the coolant in the internal combustion engine, the temperature rise of the internal combustion engine can be promoted to achieve early completion of the warm-up operation, and the coolant circulates that the heat of the high-temperature exhaust gas moves to the coolant. Since it can promote, a possibility that an exhaust heat recovery device may be damaged by exhaust heat can be reduced.

  Further, even during the warm-up operation in which the coolant is not circulated to the internal combustion engine, the coolant is heated by the exhaust heat recovery device, so that the effect of promoting the warm-up by the exhaust heat recovery device is exhibited. In addition, when the warm-up operation is completed and the engine circulation path is switched, the coolant in a place other than the place where the internal combustion engine is stopped (that is, the bypass circulation path) is preheated by the exhaust heat recovery device. Immediately after switching, low temperature coolant can be prevented from flowing into the internal combustion engine (for example, inside the water jacket). Therefore, it helps to promote warm-up operation.

  As specific examples of the pump arrangement for switching the coolant circulation to both paths as in the first aspect, the following arrangements in the second and fourth aspects can be cited. That is, in claim 2, the pump is disposed so as to be able to discharge the coolant to both the engine circulation path and the bypass circulation path (see FIG. 1). In claim 4, when the pump is arranged in the engine circulation path, and a sub-pump different from the pump is arranged in the bypass circulation path, and when switched to circulate through the bypass circulation path, The pump is controlled to stop driving, and the sub-pump is controlled to drive (see FIG. 6).

  In the pump arrangement according to the second aspect, the sub-pump according to the fourth aspect can be omitted, so that the number of parts can be reduced. On the other hand, in the pump arrangement of claim 4, for example, when it is desired to reduce the circulation flow rate to the bypass circulation path compared to the circulation flow rate to the engine circulation path, the sub pump is a small pump having a smaller maximum discharge flow rate than the pump. Can be selected. Therefore, it is possible to control the circulation flow rate with higher accuracy than in the case of controlling the low flow rate circulation with a large pump.

  Here, when switching to the bypass circulation path and recovering exhaust heat with the exhaust heat recovery unit, the knowledge that the circulation flow rate that maximizes the exhaust heat recovery efficiency is lower than the circulation flow rate to the engine circulation path The present inventors have obtained. Based on this knowledge, in the invention according to claim 3, when the bypass circulation path is switched to be circulated, the discharge flow rate of the pump is made smaller than when the engine circulation path is switched to be circulated. It is characterized by. Therefore, it is possible to improve exhaust heat recovery efficiency when switching to the bypass circulation path.

  Similarly, in the invention according to claim 5, the discharge flow rate of the sub-pump when switched to circulate the bypass circulation path is the same as that of the pump when switched to circulate the engine circulation path. It is characterized by being set smaller than the discharge flow rate. Therefore, it is possible to improve exhaust heat recovery efficiency when switching to the bypass circulation path.

  Even in the case where a thermal device that functions as a heat source is provided as described in claim 6, in the invention described in claim 1, in the warm-up operation in which the coolant is not circulated to the internal combustion engine. Even if it exists, since the cooling fluid of locations other than the location where it stops in an internal combustion engine (namely, bypass circulation path) can be heated with an exhaust heat recovery device, the amount of heat supplied to thermal equipment at the time of warm-up operation can be increased.

  According to a seventh aspect of the present invention, the valve control means is provided when the heat source is required to be supplied to the thermal device and the temperature of the coolant is higher than a predetermined lower limit temperature. The operation of the switching valve is controlled so as to circulate the engine circulation path even if it is determined that According to this, when the warm-up operation is executed by switching to the bypass circulation path when the heat source supply is required, the warm-up operation completion time is delayed, but a sufficient amount of heat is supplied to the thermal equipment. The time when you can do it early.

  Here, when it is desired to increase the heat supply amount to the thermal equipment, there is a case where the heat supply amount can be increased by setting the flow rate lower than the maximum flow rate of the engine circulation path. In view of this point, in the invention according to claim 8, when the heat source supply to the thermal equipment is requested and when switching is made to circulate the engine circulation path, the coolant is supplied to the thermal equipment. The circulation flow rate of the engine circulation path is variably controlled so that the heat supply amount of the engine satisfies the requirement. Therefore, it becomes easy to secure the required heat supply amount.

  In a ninth aspect of the invention, the thermal device is a heater core provided in an air conditioning unit that blows warm air into a vehicle interior, and when the heat source supply to the heater core is required, and the engine circulation path When there is a shortage of heat supply from the coolant in response to the request, the heat supply is determined by the heat supply shortage determination means. When it is determined that the air flow is insufficient, the air flow rate by the air conditioning unit is reduced or made zero.

  As described above, when the thermal device is a heater core, there is a concern that wind having a temperature lower than a desired temperature may be blown into the vehicle interior if the heat supply is insufficient. On the other hand, in the invention according to the ninth aspect, the amount of air blown by the air conditioning unit is reduced or made zero when the heat supply is insufficient, so that the vehicle occupant is caused by the wind lower than the desired temperature being blown into the vehicle interior. The discomfort given to can be suppressed.

  In a tenth aspect of the present invention, when a heat source supply to the thermal device is requested and when switching is made to circulate the bypass circulation path, the heat supply from the coolant in response to the request. A heat supply shortage determining means for determining whether or not the amount is insufficient, and the valve control means determines that the warm-up is required when the heat supply shortage determination means determines that the heat supply is insufficient. Even in such a case, the operation of the switching valve is controlled so that the engine circulation path is circulated.

  According to this, when the heat source supply is requested, when switching to the bypass circulation path and executing the circulation warmer operation, when the heat supply is insufficient, the engine circulation path is switched, so the circulation warmer operation is completed. Although the time is delayed, the time when the amount of heat supplied to the thermal equipment can be sufficiently secured can be accelerated.

  In the invention according to claim 11, the heat supply shortage determining means determines that the heat supply is insufficient when the temperature of the cooling liquid at or near the outlet of the thermal device is lower than a predetermined heat supply shortage determination threshold. It is characterized by. According to this, it can be easily determined whether heat supply is insufficient.

  In the twelfth aspect of the invention, the warm-up necessity determination means determines that the warm-up is necessary when the temperature of the coolant at the outlet of the internal combustion engine or in the vicinity thereof is lower than a predetermined warm-up determination threshold. It is characterized by. According to this, it is possible to easily determine whether the warm-up is necessary.

  According to a thirteenth aspect of the present invention, the exhaust heat recovery device includes an exhaust / refrigerant heat exchanging unit that internally forms a refrigerant passage through which a refrigerant circulates to exchange heat between the exhaust and the refrigerant, and the refrigerant and the cooling. It has a refrigerant / coolant liquid heat exchanging section for exchanging heat with the liquid, and the refrigerant is configured to circulate through the refrigerant passage by convection.

  Here, when the exhaust heat recovery unit has the above-described structure in which the heat exchange between the coolant and the exhaust is performed via the refrigerant, the refrigerant temperature increases due to the heat of the high-temperature exhaust during the pump limit warm-up control, and the pressure increases. There is a concern that the refrigerant passage may be damaged by the pressure of the high-pressure refrigerant. Therefore, if the invention according to claim 1 is applied to the warm-up control system including the exhaust heat recovery device having such a structure, the above-mentioned concern is preferably solved.

  Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are denoted by the same reference numerals in the drawings, and the description of the same reference numerals is used.

(First embodiment)
FIG. 1 is a diagram showing a circulation path of an engine coolant (hereinafter simply referred to as cooling water) that cools the engine 10 for an engine 10 (internal combustion engine) that is mounted on a vehicle and serves as a travel drive source.

  An electric W / P 11 driven by an electric motor is used for a water pump 11 (hereinafter referred to as W / P) that circulates engine cooling water, and an electric W / P 11 driven by an electric control unit (hereinafter referred to as ECU 12). The operation of / P11 is duty controlled.

  The circulation path includes a bypass circulation path J2 that bypasses the engine 10 and circulates cooling water as indicated by an arrow in FIG. 1A, and cools the engine 10 as indicated by an arrow in FIG. 1B. An engine circulation path J1 for circulating water so as to flow in is provided. The circulation path is provided with a first solenoid valve V1 (switching valve) and a second solenoid valve V2 (switching valve). By switching the operation of these solenoid valves V1, V2, both paths J1, J2 is switched to which cooling water is circulated.

  More specifically, the circulation path of the cooling water is provided with a bypass passage B1 that flows by bypassing the engine 10, and the first solenoid valve V1 is provided at the upstream branch point of the bypass passage B1, and the downstream branch point. Is provided with a second electromagnetic valve V2. These solenoid valves V1 and V2 are three-way valves. The first solenoid valve V1 is changed from the symbol A to C (hereinafter referred to as A → C) in FIG. 1, and the second solenoid valve V2 is changed. When operated to circulate from C to B, the cooling water circulates in the bypass circulation path J2, and when operated to circulate the first electromagnetic valve V1 from A to B and the second electromagnetic valve V2 from A to B, the engine The cooling water circulates through the circulation path J1.

  The bypass passage B1 branches off from a route from the electric W / P 11 to the engine 10. Therefore, the electric W / P 11 can discharge the cooling water to both the engine circulation path J1 and the bypass circulation path J2 in accordance with the operating state of both electromagnetic valves V1, V2.

  Next, the flow of the cooling water in a state where both the solenoid valves V1, V2 are switched so as to circulate through the engine circulation path J1 (state in FIG. 1B) will be described.

  When the electric W / P 11 is operated in the switching state of FIG. 1 (b), the cooling water in the water jacket 13 attached to the engine 10 is connected to the circulation path J3 leading to the radiator 14 (cooling heat exchanger) and later. It branches and flows to a circulation path leading to the exhaust heat recovery unit 30 to be described in detail.

  The cooling water that has flowed to the radiator 14 flows through the thermostat 15 and returns to the electric W / P 11. Outside air is blown to the radiator 14 by a cooling fan (not shown), whereby the cooling water heated by the engine 10 in the water jacket 13 is cooled by exchanging heat with the outside air. The thermostat 15 controls the circulation opening degree of the circulation path in accordance with the temperature of the cooling water. The higher the cooling water temperature, the larger the circulation opening degree and the circulation flow rate of the cooling water, and the degree of cooling by the radiator 14. To raise.

  The cooling water that has flowed to the exhaust heat recovery device 30 flows through the heater core 41 and the thermostat 15 described later in detail, and returns to the electric W / P 11. A part of the cooling water flowing through such a circulation path is branched and distributed to a throttle valve 16 (thermal device) that controls the intake flow rate to the combustion chamber. According to this, even if the condensed water adhering to the throttle valve 16 is frozen when the engine 10 is stopped, it can be thawed early by the heat of the cooling water flowing to the throttle valve 16. Therefore, the malfunction due to the freezing of the throttle valve 16 can be eliminated at an early stage.

  On the other hand, when the electric W / P11 is operated in a state where both the solenoid valves V1 and V2 are switched so as to circulate through the bypass circulation path J2 (the state shown in FIG. 1A), the cooling water discharged from the electric W / P11 is The engine 10 is bypassed, the exhaust heat recovery device 30, the heater core 41 (thermal equipment), and the thermostat 15 are circulated in order, and the electric W / P 11 is returned. At this time, the cooling water does not flow into the water jacket 13, and the cooling water in the water jacket 13 stops and is continuously heated by the combustion heat of the engine 10.

  Next, the structure of the exhaust heat recovery device 30 will be described with reference to FIG. FIG. 2 is a schematic view showing a single unit of the exhaust heat recovery device 30 as seen from the upstream side in the exhaust flow direction.

  The exhaust heat recovery device 30 forms therein a refrigerant passage (a portion with a halftone dot in FIG. 2) through which the refrigerant circulates, and an evaporator 31 (exhaust gas) that exchanges heat between the exhaust discharged from the engine 10 and the refrigerant. / Refrigerant heat exchanging part) and a condensing part 32 (refrigerant / coolant liquid heat exchanging part) for exchanging heat between the refrigerant and the coolant, and the refrigerant is configured to circulate through the refrigerant passage by convection. .

  The evaporating unit 31 is provided in a first housing 33 disposed in the exhaust pipe 17 of the engine 10, and is configured to exchange heat between the exhaust and the refrigerant to evaporate the refrigerant. . Incidentally, reference numeral 18 in FIG. 1 indicates a catalyst device for purifying exhaust gas, and the first casing 33 is disposed in the exhaust pipe 17 on the downstream side of the exhaust gas flow of the catalyst device 18.

  The condensing unit 32 is provided outside the exhaust pipe 17 and is provided in the second casing 34 disposed in the cooling water circulation path J2. And the condensation part 32 is comprised so that a refrigerant | coolant may be condensed by performing heat exchange between the refrigerant | coolant evaporated in the evaporation part 31, and engine cooling water. The second housing 34 is provided with an inlet 34a through which the cooling water flowing out from the water jacket 13 flows into the internal space 34c of the housing 34, and an outlet 34b through which the cooling water flows out from the internal space 34c of the housing 34. It has been.

  Next, a specific configuration of the evaporation unit 31 will be described. The evaporation unit 31 includes a plurality of evaporation side heat pipes 31a and corrugated fins 31b joined to the outer surface of the evaporation side heat pipe 31a. A plurality of the evaporation side heat pipes 31a are arranged in parallel (stacked arrangement) in a direction perpendicular to the flow direction of the exhaust gas (perpendicular to the plane of FIG. 2). Evaporation side heat pipes 31a are respectively provided with evaporation side headers 31c communicating with all the evaporation side heat pipes 31a at both ends in the longitudinal direction.

  Next, a specific configuration of the condensing unit 32 will be described. The condensing unit 32 includes a plurality of condensing side heat pipes 32a and straight fins 32b joined to the outer surface of the condensing side heat pipe 32a. A plurality of condensing-side heat pipes 32a are arranged in parallel (stacked arrangement) in a direction perpendicular to the flow direction of the exhaust gas. Condensation side headers 32c communicating with all the condensation side heat pipes 32a are provided at both ends in the longitudinal direction of the evaporation side heat pipe 31a.

  The evaporation side header 31c and the condensation side header 32c are connected in a communicating state. A closed loop is formed by the evaporation side and condensation side heat pipes 31a and 32a and the evaporation side and condensation side headers 31c and 32c, and a refrigerant capable of evaporating and condensing such as water and alcohol is enclosed in these. Yes.

  In addition, you may make it arrange | position the valve mechanism 35 shown by the dashed-dotted line in FIG. 2 to the condensation side header 32c. The valve mechanism 35 is a diaphragm type opening / closing means that opens and closes the flow path according to the internal pressure (refrigerant pressure) of the evaporation side heat pipe 31a. Specifically, the valve mechanism 35 closes when the internal pressure rises at a predetermined cooling water temperature and exceeds a first predetermined pressure from a normal valve opening state, and conversely the internal pressure decreases and the first predetermined pressure decreases. When the pressure falls below the lower second predetermined pressure, the valve is opened again. As a result, the exhaust heat recovery amount can be reduced in order to avoid an overheating state of the cooling water due to excessive heating of the cooling water with the exhaust heat during a high engine load in summer.

  Next, the configuration of the air conditioning unit 40 provided with the heater core 41 will be described with reference to FIG.

  The air conditioning unit 40 air-conditions the vehicle interior by blowing warm air or cold air into the vehicle interior, and is disposed outside the engine room (for example, inside the instrument panel). The air conditioning unit 40 includes an air conditioning case 42 that forms an air passage therein. A heater core 41 (heating heat exchanger) and an evaporator 43 (cooling heat exchanger) are disposed in the air conditioning case 42. Then, the air blown into the air passage by the blower 44 passes through the evaporator 43 and the heater core 41 and is subjected to heat exchange so as to reach a desired temperature, and then blown out as conditioned air toward the vehicle interior.

  Therefore, even when the air conditioning unit 40 is requested to perform the heating operation, if the temperature of the cooling water flowing through the heater core 41 is not equal to or higher than a predetermined temperature (for example, 60 ° C. or higher), the desired temperature is exceeded. The operation of the blower 44 is prohibited in order to avoid blowing out low-temperature conditioned air into the passenger compartment.

  Next, the control content of both electromagnetic valves V1, V2 and electric W / P11 by the ECU 12 will be described.

  The ECU 12 includes a detection signal output from the Eng outlet water temperature sensor 20 that detects the temperature of the cooling water at the outlet portion of the water jacket 13 (hereinafter referred to as “Eng outlet water temperature Tw”), and the temperature of the cooling water at the outlet portion of the heater core 41 ( Hereinafter, the detection signal output from the H / C outlet water temperature sensor 41a for detecting the H / C outlet water temperature Twh) is input.

  A microcomputer (hereinafter referred to as a microcomputer) (not shown) provided in the ECU 12 performs duty control on the operation of the electric W / P 11 based on detection signals from the water temperature sensors 20 and 41a, and the first electromagnetic valve V1 and The operation of the second solenoid valve V2 is controlled. Thus, ECU12 which controls the action | operation of both electromagnetic valves V1, V2 is corresponded to the "valve control means" as described in a claim. FIG. 3 is a flowchart showing a processing procedure that is repeatedly executed by the CPU of the microcomputer of the ECU 12, and the processing execution is started when an ignition switch (not shown) is turned on.

  First, in step S10, the detection signal from the Eng outlet water temperature sensor 20 and the H / C outlet water temperature sensor 41a and the heating request signal from the air conditioning unit 40 are read as parameters representing the operating state of the vehicle. That is, the Eng outlet water temperature Tw at the engine 10 outlet portion, the H / C outlet water temperature Twh at the heater core 41 outlet portion, and the heating request signal are acquired. The heating request signal is output according to the operation state of an air conditioning switch (not shown) by a vehicle occupant, and in the case of an auto air conditioner that automatically controls the air conditioning air temperature, it is selected based on the indoor set temperature, the outside air temperature, etc. When the air conditioning mode is the heating mode, a heating request signal is output, and in the case of a manual air conditioner that manually operates the air conditioning air temperature, a heating request signal is output with the heating operation by the passenger.

  Next, in step S20 (warm-up necessity determination means), it is determined whether or not the acquired Eng outlet water temperature Tw is higher than a preset warm-up determination threshold Ta. The determination in step S20 is for determining whether or not the engine 10 requires a warm-up operation. Therefore, the warm-up determination threshold value Ta is set to about 95 ° C., for example.

  If it is determined that Tw> Ta (S20: YES), it is determined that the warm-up operation is unnecessary, and the process proceeds to step S30, and both solenoid valves V1, V2 are operated so that the cooling water flows into the engine 10. Subsequently, in step S40, duty control is performed so as to maximize the discharge flow rate of the electric W / P 11 (see FIG. 1A). Incidentally, in the present embodiment employing on-duty control, the discharge flow rate is maximized by setting the duty ratio to 100%. As described above, the cooling water circulates at the maximum flow rate in the engine circulation path J1 when the warm-up is unnecessary.

  As a result, the degree to which the cooling water is cooled by the radiator 14 is maximized, thereby avoiding insufficient cooling of the engine 10. In this case, the circulating flow rate of the cooling water is adjusted by the action of the thermostat 15 so that the engine 10 reaches the optimum temperature.

  On the other hand, if it determines with Tw <= Ta (S20: NO), it will consider that warming-up operation is required, and a process will progress to step S21, and it will be determined whether the heating request signal is read. If there is no heating request (S21: YES), the process proceeds to step S31, where both solenoid valves V1, V2 are operated so that the cooling water flows through the bypass passage B1, and the discharge flow rate of the electric W / P 11 is reduced in the subsequent step S41. Duty control is performed so that the flow rate (for example, the duty ratio is 5%) (see FIG. 1A). As described above, when there is a warm-up request and no heating request, the cooling water circulates at a low flow rate in the bypass circulation path J2.

  Thereby, the cooling water in the water jacket 13 stops. Therefore, since the temperature rise of the cooling water in the water jacket 13 is promoted, the temperature rise of the engine 10 can be promoted, and as a result, the warm-up operation of the engine 10 can be completed early.

  Next, when there is a heating request (S21: NO), it is determined in subsequent step S22 whether the H / C outlet water temperature Twh is lower than the Eng outlet water temperature Tw. In the case of Twh <Tw (S22: YES), it is determined whether or not the Eng outlet water temperature Tw is higher than a predetermined warm-up water temperature Tb (lower limit temperature). In the case of Twh ≧ Tw (S22: NO) Then, it is determined whether or not the H / C outlet water temperature Twh is higher than a predetermined lower limit temperature Tb.

  When the temperature of the cooling water flowing into the heater core 41 reaches the warm-up water temperature Tb, it is assumed that even if the blower 44 of the air conditioning unit 40 is operated, cool air that does not feel strange to the vehicle occupant who requests heating is assumed. is doing. Therefore, the warm-up water temperature Tb is set to a temperature that satisfies this assumption, that is, a temperature lower than the warm-up determination threshold value Ta (for example, 60 ° C.). When it is estimated that the temperature of the cooling water flowing into the heater core 41 has not reached the warm-up water temperature Tb, the operation of the blower 44 is stopped. Thereby, it is avoided that cold air is blown out into the passenger compartment when heating is requested.

  When Tw ≦ Tb (S23: NO), both solenoid valves V1, V2 are operated so that the cooling water flows through the bypass passage B1 (S31), and the discharge flow rate of the electric W / P11 is reduced ( For example, the duty control is performed so that the duty ratio is 5% (S41). Therefore, even when there is a warm-up request and there is a heating request, when it is estimated that the warm-up water temperature Tb has not been reached (that is, when Tw ≦ Tb), the bypass circulation path J2 is cooled at a low flow rate. Water circulates. Thereby, the cooling water in the water jacket 13 is stopped and the warm-up operation of the engine 10 is promoted, and the temperature rise to the warm-up water temperature Tb is promoted.

  Here, when the exhaust heat recovery unit 30 recovers exhaust heat by switching to the bypass circulation path J2, the circulation flow rate at which the exhaust heat recovery efficiency is maximized is compared with the circulation flow rate (that is, the maximum flow rate) to the engine circulation path J1. The present inventors have found that the flow rate is low. The low flow rate is set to a flow rate with a duty ratio of 5% based on the results of tests and the like conducted in advance. Based on this knowledge, in step S41, since the discharge flow rate of the electric W / P 11 is set to a low flow rate, the heating of the cooling water by the exhaust heat recovery device 30 can be promoted, and the effect of promoting the warm-up by the exhaust heat recovery device 30 is achieved. Is done. In addition, when the warm-up operation is finished and switching to the engine circulation path J1 in step S30, the degree to which the exhaust water heat recovery device 30 preliminarily heats the cooling water in places other than the water jacket 13 (that is, the bypass circulation path J2). Therefore, it is possible to suppress the low-temperature cooling water from flowing into the water jacket 13 immediately after switching to the engine circulation path J1. Therefore, it helps to promote warm-up operation.

  On the other hand, when it is determined that the Eng outlet water temperature Tw has risen to the warm-up water temperature Tb (Tw> Tb) (S23: YES), both solenoid valves V1, V2 are set so that the cooling water flows into the engine 10. Is operated (S32), and duty control is performed so that the discharge flow rate of the electric W / P11 is set to a low flow rate (for example, the duty ratio is 5%) (S41). According to this, although it is determined that warm-up is required (Tw ≦ Ta) in step S20, it is not necessary to wait for the Eng outlet water temperature Tw to rise to the warm-up determination threshold Ta (95 ° C.). Thus, the cooling water having a high temperature is supplied to the heater core 41. Therefore, the cooling water flowing into the heater core 41 at the time of the heating request can be quickly brought to the warm-up temperature Tb, and when the heating request is made at the cold start of the engine 10, the blower is operated at an early stage to Wind can be blown into the passenger compartment.

  Here, when switching to the bypass circulation path J2, it should be basically Twh <Tw. However, when the exhaust heat recovery efficiency in the exhaust heat recovery unit 30 is high, it is determined that the H / C outlet water temperature Twh has increased to the warm-up water temperature Tb (Twh> Tb) (S24: YES). There is.

  In this case, if the H / C outlet water temperature Twh has reached the warm-up water temperature Tb (S24: YES), both electromagnetics are set so that the cooling water flows through the bypass passage B1 on condition that the heat supply amount described later is not insufficient. The valves V1 and V2 are operated (S34), and duty control is performed so that the discharge flow rate of the electric W / P11 is low (for example, the duty ratio is 5%) (S43). Thereby, the cooling water in the water jacket 13 is stopped and the warm-up operation of the engine 10 is promoted, and the cooling water having a temperature that has reached the warm-up water temperature Tb can be supplied to the heater core 41.

  However, if it is determined in step S25 (heat supply shortage determination means) that the heat supply amount is insufficient (described later) (S25: YES), both solenoid valves V1 and V2 are operated so that the cooling water flows into the engine 10. (S33), duty control is performed so that the discharge flow rate of the electric W / P 11 is set to a low flow rate (for example, the duty ratio is 5%) (S42).

  In step S25, the engine 10 is bypassed by determining whether or not the H / C outlet water temperature Twh has greatly decreased as a result of operating the blower 41 when the H / C outlet water temperature Twh becomes the warm-up temperature Tb. Then, it is determined whether or not the heat supply amount to the heater core 41 is insufficient by merely heating the cooling water in the exhaust heat recovery unit 30. Specifically, it is determined that the heat supply amount is insufficient when the H / C outlet water temperature Twh is lower than the heat supply shortage determination threshold value Tc.

  According to this, even if it is determined that Twh ≧ Tw (S22: NO) and Twh> Tb (S24: YES), if it is determined that the amount of heat supplied to the heater core 41 is insufficient (S25: YES), the cooling water supplied to the heater core 41 is heated by the engine 10 in addition to the exhaust heat recovery device 30. Therefore, the shortage of heat supply can be solved.

  Next, the effect by this embodiment provided with the said structure and control is demonstrated using FIG.4 and FIG.5.

  FIGS. 4 and 5 are time charts showing one mode when the control of FIG. 3 is performed, and the Eng outlet water temperature Tw, the engine warm-up request flag, the duty ratio when duty-controlling the electric W / P 11, It is a figure which shows each change about the control position (switching state) of 1 solenoid valve V1 and 2nd solenoid valve V2, and the output level (air volume) of the blower 44. FIG. FIG. 4A shows one mode when there is no heating request (S21: YES), and FIG. 4B shows one mode when there is a heating request (S21: NO). Further, in the case where there is a heating request, FIG. 5A shows one mode in which the necessary heat supply amount to the heater core 41 can be secured only by the exhaust heat recovery device 30 (S25: NO), and FIG. Indicates one mode when the necessary heat supply amount cannot be secured (S25: YES).

<When there is no heating request: FIG. 4A>
First, when the engine 10 is started, the Eng outlet water temperature Tw gradually increases. Then, until the time point t10 when the Eng outlet water temperature Tw reaches the warm-up determination threshold Ta (95 ° C.), the cooling water is circulated to the bypass circulation path J2 in accordance with the determination that warm-up is required in step S20 (S31, S41). When the Eng outlet water temperature Tw reaches 95 ° C., the cooling water is caused to flow into the engine 10 in accordance with the determination that the warm-up is unnecessary in step S20 (S30, S40).

<When there is a heating request: FIG. 4B>
First, when the engine 10 is started, the Eng outlet water temperature Tw gradually increases. Then, until the time point t1 when the Eng outlet water temperature Tw reaches the warm-up water temperature Tb (60 ° C.), the cooling water is circulated to the bypass circulation path J2 by determining that Tw ≦ Tb in step S23 (S31, S41). ).

  When the Eng outlet water temperature Tw reaches 60 ° C., it is determined that Tw> Tb in step S23, and the cooling water is caused to flow into the engine 10 (S32, S41) and the output level (air volume) of the blower 44 is set. Increase gradually. Thereafter, at the time t10 when the Eng outlet water temperature Tw reaches the warm-up determination threshold Ta (95 ° C.), the coolant is caused to flow into the engine 10 in accordance with the determination that warm-up is not required in step S20 (S30, S40).

  Here, until the Eng outlet water temperature Tw reaches 95 ° C. and the warm-up is not required, the exhaust heat recovery unit 30 recovers the exhaust heat so that the exhaust heat recovery efficiency is maximized. In the example of FIG. 4B, the circulation flow rate (for example, duty ratio 50%) from t1 to t10 switched to the engine circulation path J1 is the circulation flow rate (for example, duty ratio) to the time t1 when switching to the bypass circulation path J2. Ratio 5%).

<When the heat supply amount necessary for heating can be secured only by the exhaust heat recovery device 30: FIG. 5A>
First, when the engine 10 is started, the Eng outlet water temperature Tw gradually increases. Then, until the time point t2 when the H / C outlet water temperature Twh reaches the warm-up water temperature Tb (60 ° C.), the cooling water is circulated to the bypass circulation path J2 in accordance with the determination of Twh ≦ Tb in step S24 (S34). , S43), and then when the H / C outlet water temperature Twh reaches 60 ° C. at time t2, the blower 44 is started to operate.

  And since the H / C outlet water temperature Twh did not fall below the heat supply shortage determination threshold value Tc (55 ° C.) with the start of the operation of the blower 44, the heat supply amount can be secured only by the exhaust heat recovery device 30. It is determined (S25: NO), and the cooling water circulation to the bypass circulation path J2 is continued (S34, S43). In addition, the heating flow performance is secured by increasing the discharge flow rate of the electric W / P11.

  Thereafter, at the time t10 when the Eng outlet water temperature Tw reaches the warm-up determination threshold Ta (95 ° C.), the coolant is caused to flow into the engine 10 in accordance with the determination that warm-up is not required in step S20 (S30, S40). Further, the discharge flow rate of the electric W / P 11 is increased to avoid an abnormal rise (overheat) of the Eng outlet water temperature Tw.

<When the exhaust heat recovery device 30 alone cannot secure the amount of heat supply required for heating: FIG. 5B>
First, when the engine 10 is started, the Eng outlet water temperature Tw gradually increases. Then, until the time point t3 when the H / C outlet water temperature Twh reaches the warm-up water temperature Tb (60 ° C.), the cooling water is circulated to the bypass circulation path J2 by determining that Twh ≦ Tb in step S24 (S34). , S43), and thereafter, when the H / C outlet water temperature Twh reaches 60 ° C. at time t3, the operation of the blower 44 is started. In addition, the heating flow performance is secured by increasing the discharge flow rate of the electric W / P11.

  Thereafter, at time t4, the H / C outlet water temperature Twh has decreased below the heat supply shortage determination threshold Tc (55 ° C.) with the start of operation of the blower 44 at time t3. It is determined that it cannot be secured (S25: YES), and the operation of the blower 44 is stopped. Thereafter, the operation of the blower 44 is restarted when Twh> 55 ° C. is reached at time t5 when a predetermined time has elapsed, and as a result, if Twh ≦ 55 ° C. is not satisfied, the output level (air volume) of the blower 44 is gradually increased. Raise.

  Thereafter, at time t6, when the H / C outlet water temperature Twh (or the Eng outlet water temperature Tw) reaches 60 ° C. again, it is determined that there is a history that the heat supply amount cannot be secured only by the exhaust heat recovery device 30 (S25: YES). The cooling water circulation to the bypass circulation path J2 is switched to the engine circulation path J1 (S33, S42). As a result, the cooling water supplied to the heater core 41 is also heated by the engine 10 in addition to the exhaust heat recovery device 30, and the shortage of the heat supply amount is solved.

  Thereafter, at the time t10 when the Eng outlet water temperature Tw reaches the warm-up determination threshold Ta (95 ° C.), the coolant is caused to flow into the engine 10 in accordance with the determination that warm-up is not required in step S20 (S30, S40). Further, the discharge flow rate of the electric W / P 11 is increased to avoid an abnormal rise (overheat) of the Eng outlet water temperature Tw.

  As described above, according to this embodiment with the above configuration and control, when the warm-up is required, the bypass circulation path J2 is circulated, so that the cooling water in the water jacket 13 is stopped and the exhaust heat recovery device 30 is stopped. Cooling water can be circulated. Therefore, it is possible to accelerate the temperature rise of the engine 10 by stopping the cooling water in the engine 10 to achieve the early completion of the warm-up operation, and the cooling water circulates that the heat of the high-temperature exhaust gas moves to the cooling water. Therefore, the possibility that the exhaust heat recovery device 30 is damaged by the exhaust heat can be reduced.

  Further, even during the warm-up operation in which the cooling water does not flow into the engine 10, the cooling water is heated by the exhaust heat recovery device 30, so that the effect of promoting the warm-up by the exhaust heat recovery device 30 is exhibited. Moreover, since the cooling water in the bypass circulation path J2 is preheated by the exhaust heat recovery device 30 when the warm-up operation ends and the cooling water flows into the engine 10, the cooling water is cooled to the engine 10 at a low temperature. Water can be prevented from flowing into the engine 10. Therefore, it helps to promote warm-up operation.

(Second Embodiment)
FIG. 6 is a diagram illustrating a circulation path of the cooling water according to the present embodiment.

  The circulation path includes a bypass circulation path J20 that bypasses the engine 10 and circulates cooling water as indicated by an arrow in FIG. 6 (a), and cooling to the engine 10 as indicated by an arrow in FIG. 6 (b). An engine circulation path J10 that circulates water to flow in is provided. The circulation path is provided with a third solenoid valve V3 (switching valve) and a fourth solenoid valve V4 (switching valve). By switching the operation of these solenoid valves V3, V4, both paths J10, J20 is switched to which cooling water is circulated.

  More specifically, a three-way valve is adopted for both the electromagnetic valves V3 and V4, and the third electromagnetic valve V3 is changed from the symbol A to C (hereinafter referred to as A → C) in FIG. When the fourth solenoid valve V4 is operated to flow from C to B, the cooling water circulates in the bypass circulation path J20, the third solenoid valve V3 is passed from A to B, and the fourth solenoid valve V4 is passed from A to B. When operated, the cooling water circulates through the engine circulation path J10.

  Electric W / P11 (hereinafter referred to as main W / P11 in the present embodiment) is arranged on engine circulation path J10, and sub W / P11s different from main W / P11 is arranged on bypass circulation path J20. ing. Accordingly, when the third electromagnetic valve V3 is operated from A → C and the fourth electromagnetic valve V4 is operated from C → B to drive the sub W / P 11s, the cooling water circulates in the bypass circulation path J20. Further, when the main W / P 11 is driven by operating the third solenoid valve V3 from A → B and the fourth solenoid valve V4 from A → B, the coolant circulates through the engine circulation path J10.

  Next, the flow of the cooling water in a state where both the electromagnetic valves V3 and V4 are switched so as to circulate through the engine circulation path J10 (the state shown in FIG. 6B) will be described.

  When the main W / P 11 is operated in the switching state of FIG. 6B, the cooling water inside the water jacket 13 branches and flows into a circulation path J3 leading to the radiator 14 and a circulation path leading to the exhaust heat recovery device 30. . The cooling water flowing to the radiator 14 flows through the thermostat 15 and returns to the main W / P 11. The cooling water that has flowed to the exhaust heat recovery device 30 flows through the heater core 41 and the thermostat 15 in order and returns to the main W / P 11. A part of the cooling water flowing through such a circulation path is branched and distributed to a throttle valve 16 (thermal device) that controls the intake flow rate to the combustion chamber.

  On the other hand, when the sub W / P 11s is operated in a state where both the solenoid valves V3 and V4 are switched so as to circulate the bypass circulation path J20 (the state of FIG. 6A), the cooling water discharged from the sub W / P 11s is The engine 10 is bypassed, the exhaust heat recovery device 30, the heater core 41, and the thermostat 15 are circulated in order, and the process returns to the main W / P11. At this time, the cooling water does not flow into the water jacket 13, and the cooling water in the water jacket 13 stops and is continuously heated by the combustion heat of the engine 10.

  Next, the control contents of both solenoid valves V3 and V4 and both W / P11 and 11s by the ECU 12 will be described.

  The microcomputer of the ECU 12 controls the operations of the main W / P 11 and the sub W / P 11 s based on the detection signals from the water temperature sensors 20 and 41 a and controls the operations of the third electromagnetic valve V 3 and the fourth electromagnetic valve V 4. . FIG. 7 is a flowchart showing a processing procedure that is repeatedly executed by the CPU of the microcomputer of the ECU 12. When an ignition switch (not shown) is turned on, the processing is started.

  In steps S10 to S34 in FIG. 7, the same processes as those in steps S10 to S34 in FIG. And step S50, S60 of FIG. 7 concerning this embodiment is a process performed instead of step S40 of FIG.

  When the warm-up is not required (S20: YES), the discharge flow rate of the main W / P11 is maximized in step S50, and the drive of the sub W / P11s is stopped in step S60. Therefore, the cooling water circulates at the maximum flow rate in the engine circulation path J10 when the warm-up is unnecessary.

  If warming up is required (S20: NO) and there is no heating request (S21: YES), the sub W / P 11s is driven at the maximum discharge flow rate in step S51, and the main W / P 11 is set in step S61. Stop driving. As the sub W / P 11s, a small pump having a smaller maximum discharge flow rate than that of the main W / P 11 is selected. Therefore, the circulation flow rate in the bypass circulation path J20 in steps S51 and S61 is lower than the circulation flow rate in the engine circulation path J10 in steps S50 and S60 when the warm-up is not required.

  When warming up is required (S20: NO), heating is requested (S21: YES), and Tw> Tb (S23: YES), the main W / P11 is driven at a low flow rate in step S52. In step S62, the driving of the sub W / P 11s is stopped.

  Further, there is a history that warm-up is required (S20: NO), heating is requested (S21: YES), Twh> Tb (S23: YES), and the heat supply amount cannot be secured only by the exhaust heat recovery device 30 (S25: In the case of YES), the main W / P11 is driven at a low flow rate in step S53, and the driving of the sub W / P11s is stopped in step S63.

  Further, warm-up required (S20: NO), heating requested (S21: YES), Twh> Tb (S23: YES), and there is no history that the heat supply amount cannot be secured only with the exhaust heat recovery device 30 (S25: In the case of NO), the sub W / P 11s is driven at the maximum discharge flow rate in step S54, and the drive of the main W / P 11 is stopped in step S64.

  Next, the effect by this embodiment provided with the said structure and control is demonstrated using FIG.8 and FIG.9.

  FIG. 8A shows one mode when there is no heating request (S21: YES), and FIG. 8B shows one mode when there is a heating request (S21: NO). Further, in the case where there is a heating request, FIG. 9A shows one mode in which the necessary heat supply amount to the heater core 41 can be secured only by the exhaust heat recovery device 30 (S25: NO), and FIG. Indicates one mode when the necessary heat supply amount cannot be secured (S25: YES).

<When there is no heating request: FIG. 8A>
First, when the engine 10 is started, the Eng outlet water temperature Tw gradually increases. Then, until the time t20 when the Eng outlet water temperature Tw reaches the warm-up determination threshold value Ta (95 ° C.), the cooling water is circulated to the bypass circulation path J20 as it is determined that the warm-up is required in step S20 (S31, S51, S61). Then, when the Eng outlet water temperature Tw reaches 95 ° C., the cooling water is caused to flow into the engine 10 as it is determined in step S20 that the warm-up is not required (S30, S50, S60).

<When there is a heating request: FIG. 8B>
First, when the engine 10 is started, the Eng outlet water temperature Tw gradually increases. Then, until the time point t11 when the Eng outlet water temperature Tw reaches the warm-up water temperature Tb (60 ° C.), the cooling water is circulated to the bypass circulation path J20 in accordance with the determination of Tw ≦ Tb in step S23 (S31, S51). , S61).

  When the Eng outlet water temperature Tw reaches 60 ° C., it is determined in step S23 that Tw> Tb, and the cooling water is caused to flow into the engine 10 (S32, S52, S62) and the output level (air volume) of the blower 44. ) Is gradually increased. Thereafter, at the time t20 when the Eng outlet water temperature Tw reaches the warm-up determination threshold Ta (95 ° C.), the coolant is caused to flow into the engine 10 in accordance with the determination that the warm-up is unnecessary in step S20 (S30, S50, S60). ).

  Here, until the Eng outlet water temperature Tw reaches 95 ° C. and the warm-up is not required, the exhaust heat recovery unit 30 recovers the exhaust heat so that the exhaust heat recovery efficiency is maximized. In the example of FIG. 8B, the circulation flow rate (for example, duty ratio 50%) from t11 to t20 is set to be smaller than the circulation flow rate (for example, duty ratio 100%) after time t20.

<When the heat supply amount necessary for heating can be ensured only with the exhaust heat recovery device 30: FIG. 9A>
First, when the engine 10 is started, the Eng outlet water temperature Tw gradually increases. Then, until the time point t12 when the H / C outlet water temperature Twh reaches the warm-up water temperature Tb (60 ° C.), the cooling water is circulated to the bypass circulation path J20 in accordance with the determination of Twh ≦ Tb in step S24 (S34). , S54, S64), and then when the H / C outlet water temperature Twh reaches 60 ° C. at time t12, the blower 44 is started to operate.

  And since the H / C outlet water temperature Twh did not fall below the heat supply shortage determination threshold value Tc (55 ° C.) with the start of the operation of the blower 44, the heat supply amount can be secured only by the exhaust heat recovery device 30. The determination (S25: NO) is made, and the cooling water circulation to the bypass circulation path J20 is continued (S34, S54, S64). Thereafter, at the time t20 when the Eng outlet water temperature Tw reaches the warm-up determination threshold Ta (95 ° C.), the coolant is caused to flow into the engine 10 in accordance with the determination that the warm-up is unnecessary in step S20 (S30, S50, S60). ).

<When the exhaust heat recovery device 30 alone cannot secure the amount of heat supply required for heating: FIG. 9B>
First, when the engine 10 is started, the Eng outlet water temperature Tw gradually increases. Then, until the time point t13 when the H / C outlet water temperature Twh reaches the warm-up water temperature Tb (60 ° C.), the cooling water is circulated to the bypass circulation path J20 in accordance with the determination of Twh ≦ Tb in step S24 (S34). , S54, S64), and then when the H / C outlet water temperature Twh reaches 60 ° C. at time t13, the blower 44 is started to operate.

  Thereafter, at time t14, the H / C outlet water temperature Twh has decreased below the heat supply shortage determination threshold Tc (55 ° C.) with the start of operation of the blower 44 at time t13. It is determined that it cannot be secured (S25: YES), and the operation of the blower 44 is stopped. Thereafter, the operation of the blower 44 is restarted as Twh> 55 ° C. at a time t15 when a predetermined time has elapsed, and if the result does not satisfy Twh ≦ 55 ° C., the output level (air volume) of the blower 44 is gradually increased. Raise.

  Thereafter, at time t16, when the H / C outlet water temperature Twh (or the Eng outlet water temperature Tw) reaches 60 ° C. again, it is determined that there is a history that the heat supply amount cannot be ensured only by the exhaust heat recovery device 30 (S25: YES). The cooling water circulation to the bypass circulation path J20 is switched to the engine circulation path J10 (S33, S53, S63). As a result, the cooling water supplied to the heater core 41 is also heated by the engine 10 in addition to the exhaust heat recovery device 30, and the shortage of the heat supply amount is solved. Thereafter, at the time t20 when the Eng outlet water temperature Tw reaches the warm-up determination threshold Ta (95 ° C.), the coolant is caused to flow into the engine 10 in accordance with the determination that the warm-up is unnecessary in step S20 (S30, S50, S60). ).

  As described above, the same effects as those of the first embodiment are also exhibited by this embodiment by the above configuration and control. That is, when the warm-up is required, the bypass circulation path J20 is circulated, so that the temperature rise of the engine 10 can be promoted by stopping the cooling water in the engine 10 and the warm-up operation can be completed early, and the exhaust heat The possibility that the collector 30 is damaged by the exhaust heat can be reduced. Further, even during the warm-up operation in which the cooling water does not flow into the engine 10, the cooling water is heated by the exhaust heat recovery device 30, so that the effect of promoting the warm-up by the exhaust heat recovery device 30 is exhibited. In addition, when the warm-up operation is finished and the cooling water is started to flow into the engine 10, it is possible to suppress the low-temperature cooling water from flowing into the engine 10, which helps to promote the warm-up operation.

(Other embodiments)
Each of the above embodiments may be modified as follows. In implementing the present invention, the characteristic configuration or control of each embodiment may be arbitrarily combined.

  In the second embodiment, the drive of the main W / P 11 is stopped when switching to the bypass circulation path J20. Instead of such stop control, the discharge flow rate of the main W / P 11 is less than a predetermined amount. It may be controlled to drive while limiting to the above. In this case, for example, the power supply duty ratio to the main W / P 11 may be limited to a predetermined value or less.

  In the above embodiment, the electrically driven W / P 11, 11s is employed for the pump according to the present invention. However, even when a pump driven by an engine output shaft (crankshaft) is employed, for example, If a clutch mechanism is provided in the power transmission path from the shaft to the pump, the discharge amount of the pump can be made zero (controllable) regardless of the operating state of the engine 10. Therefore, a pump with a clutch mechanism may be adopted instead of the electric W / P 11, 11s.

  Furthermore, in the first embodiment, since the electric W / P 11 may be always driven, a pump driven by a crankshaft that does not include a clutch mechanism may be employed.

  In the second embodiment, the drive of the sub W / P 11s is stopped when switching to the engine circulation path J10. At this time, the sub W / P 11s is driven to increase the circulation flow rate. Good.

  In the above embodiment, when Tw> Ta is determined in step S20 of FIGS. 3 and 7, the cooling water temperature Tw is detected by the Eng outlet water temperature sensor 20, and Tw> Ta is determined based on the detected value. However, a physical quantity that is highly correlated with the coolant temperature Tw (for example, the temperature of the cylinder head or cylinder block of the engine 10, the temperature of the lubricating oil of the engine 10, etc.) is detected by another sensor (not shown), and Tw is based on the detected value. > Ta may be determined.

  In the above-described embodiment, the duty ratio is controlled for the electric power supplied to the electric W / Ps 11 and 11s. However, on / off control that switches between energization and interruption of the electric W / Ps 11 and 11s may be used.

  In the above embodiment, the warm-up determination threshold Ta and the warm-up water temperature Tb are fixed, but at least one of both values Ta and Tb is variably set depending on, for example, whether or not there is a heating request to the air conditioning unit 40 It may be.

  In the above embodiment, the throttle valve 16 and the heater core 41 are exemplified as “thermal equipment” described in the claims, but in addition to this, for example, a heat storage tank that retains and stores heated cooling water. Is a specific example of a thermal device.

  An H / C inlet water temperature sensor that detects the temperature of the cooling water at the inlet portion of the heater core 41 instead of the H / C outlet water temperature sensor 41a that detects the temperature of the cooling water at the outlet portion of the heater core 41 (H / C outlet water temperature Twh). And the H / C outlet water temperature Twh used in the above various determinations may be replaced with the H / C inlet water temperature.

The figure which shows the circulation path of the cooling water of the engine to which the warm-up control system concerning 1st Embodiment of this invention is applied. The figure which shows the exhaust heat recovery device of FIG. The flowchart which shows the process sequence performed by ECU of FIG. The time chart which shows the one aspect | mode at the time of implementing control of FIG. The time chart which shows the one aspect | mode at the time of implementing control of FIG. The figure which shows the circulating path of the cooling water of the engine to which the warm-up control system concerning 2nd Embodiment of this invention is applied. The flowchart which shows the process sequence performed by ECU of FIG. The time chart which shows the one aspect | mode at the time of implementing control of FIG. The time chart which shows the one aspect | mode at the time of implementing control of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Engine (internal combustion engine), 11 ... Main W / P (pump), 11s ... Sub W / P (sub pump) 12 ... ECU (valve control means), 16 ... Throttle valve (thermal equipment), 30 ... Exhaust heat recovery 31 ... Evaporation part (exhaust / refrigerant heat exchange part), 32 ... Condensation part (refrigerant / coolant heat exchange part), 40 ... Air conditioning unit, 41 ... Heater core (thermal equipment), S20 ... Warming necessity determination means , S25 ... heat supply shortage determining means, J1, J10 ... engine circulation path, J2, J20 ... bypass circulation path, V1 ... first solenoid valve (switching valve), V2 ... second solenoid valve (switching valve), V3 ... first 3 solenoid valves (switching valve), V4... 4th solenoid valve (switching valve).

Claims (13)

A pump for circulating the coolant of the internal combustion engine;
An exhaust heat recovery unit that recovers exhaust heat by exchanging heat between the exhaust discharged from the internal combustion engine and the coolant;
A warm-up necessity determination unit for determining whether the internal combustion engine requires a warm-up operation;
An engine circulation path for circulating the coolant to flow into the internal combustion engine and the exhaust heat recovery unit;
A bypass circulation path for circulating the coolant to bypass the internal combustion engine and flow into the exhaust heat recovery device;
A switching valve that switches the circulation path to either the engine circulation path or the bypass circulation path;
The operation of the switching valve is controlled so that the engine circulation path is circulated when the warm-up necessity determination unit determines that the warm-up is not required, and the bypass circulation path is circulated when it is determined that the warm-up is necessary. Valve control means;
A warm-up control system for an internal combustion engine, comprising:   2. The warm-up control system for an internal combustion engine according to claim 1, wherein the pump is disposed so that the coolant can be discharged into both the engine circulation path and the bypass circulation path.   3. The internal combustion engine according to claim 2, wherein when the switching is made to circulate through the bypass circulation path, the discharge flow rate of the pump is made smaller than when the switching is made to circulate through the engine circulation path. Warm-up control system. The pump is arranged in the engine circulation path, and a sub pump different from the pump is arranged in the bypass circulation path,
2. The internal combustion engine according to claim 1, wherein the pump is controlled to stop driving and the sub-pump is controlled to drive when being switched to circulate through the bypass circulation path. Warm-up control system.   The discharge flow rate of the sub pump when switched to circulate through the bypass circulation path is set to be smaller than the discharge flow rate of the pump when switched to circulate through the engine circulation path. The warm-up control system for an internal combustion engine according to claim 4.   The warm-up control system for an internal combustion engine according to any one of claims 1 to 5, further comprising a thermal device that functions as a heat source of the coolant.   The valve control means is a case where supply of a heat source to the thermal equipment is required, and when the temperature of the coolant is higher than a predetermined lower limit temperature, it is determined that the warm-up is required. The warm-up control system for an internal combustion engine according to claim 6, wherein the operation of the switching valve is controlled so as to circulate the engine circulation path.   When supply of a heat source to the thermal device is required and when switching is made to circulate through the engine circulation path, the amount of heat supplied from the coolant to the thermal device will satisfy the request. The warm-up control system for an internal combustion engine according to claim 6 or 7, wherein the circulation flow rate of the engine circulation path is variably controlled. The thermal device is a heater core provided in an air conditioning unit that blows warm air into the vehicle interior,
Whether or not the amount of heat supplied from the coolant is insufficient with respect to the request when supply of a heat source to the heater core is requested and when switching is made to circulate the engine circulation path. A heat supply shortage determining means for determining,
9. The internal combustion engine according to claim 6, wherein when the heat supply shortage determining unit determines that the heat supply is insufficient, the air flow rate by the air conditioning unit is reduced or reduced to zero. Engine warm-up control system. Whether or not the amount of heat supplied from the coolant is insufficient with respect to the request when supply of a heat source to the thermal device is requested and when switching is made to circulate the bypass circulation path A heat supply shortage determining means for determining
When the heat supply shortage determining means determines that the heat supply is insufficient, the valve control means controls the switching valve to circulate through the engine circulation path even if it is determined that the warm-up is required. The warm-up control system for an internal combustion engine according to any one of claims 6 to 9, wherein the operation is controlled.   The heat supply shortage determining means determines that the heat supply is insufficient when the temperature of the coolant at or near the outlet of the thermal device is lower than a predetermined heat supply shortage determination threshold. The warm-up control system for an internal combustion engine according to claim 10.   The warm-up necessity determination unit determines that warm-up is necessary when the temperature of the coolant at the outlet of the internal combustion engine or in the vicinity thereof is lower than a predetermined warm-up determination threshold value. The warm-up control system for an internal combustion engine according to any one of 11.   The exhaust heat recovery unit includes a refrigerant passage in which a refrigerant circulates, an exhaust / refrigerant heat exchange unit that exchanges heat between the exhaust and the refrigerant, and a refrigerant / refrigerant that exchanges heat between the refrigerant and the coolant. A warm-up control for an internal combustion engine according to any one of claims 1 to 12, further comprising a coolant heat exchange unit, wherein the coolant circulates through the coolant passage by convection. system.

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