JP5189461B2 - Cooling device for internal combustion engine - Google Patents

Description

  The present invention relates to a cooling device for an internal combustion engine including a heat storage device (heat storage tank) that stores cooling water of an internal combustion engine (hereinafter also referred to as an engine) mounted on a vehicle or the like in a heat-retaining state.

  In a water-cooled engine mounted on a vehicle, a water jacket is provided as a cooling water passage in the engine, and the cooling water is circulated through the water jacket by a water pump so that the entire engine is uniformly cooled. However, when the engine is cold started, the low-temperature cooling water circulates through the water jacket of the engine, and the engine cannot be warmed up early. In this case, since the wall surface temperature of the intake port, the combustion chamber, etc. of the engine is lowered, the fuel is difficult to atomize, and startability and exhaust emission may be deteriorated. Further, at the time of cold start, since the temperature of the lubricating oil is low and the viscosity is high, the friction loss at the sliding portion such as between the cylinder and the piston may be high.

  As a technique for solving this problem, a part of the cooling water (high temperature water) warmed during engine operation is stored in a heat storage tank, and the high temperature water stored in the heat storage tank is used. There is a cooling device that warms the engine at the next engine start (see, for example, Patent Document 1).

In the cooling device described in Patent Document 1, a cooling circuit that circulates cooling water via an engine and a heater core, a mechanical water pump that is driven by the engine to circulate the cooling water, an engine cooling water outlet, and a heater core A heat storage tank connected between the cooling water inlet and a control valve (three-way valve) connected between the engine cooling water outlet and the cooling water inlet of the heat storage tank. The control valve (three-way valve) is controlled to switch the cooling water circuit in response to demands for hot water supply) and heat recovery (hot water recovery to the heat storage tank).
Japanese Patent Laid-Open No. 10-71838 Japanese Patent Laid-Open No. 10-77839

  By the way, in the cooling device described in Patent Document 1, since the water pump depends on the engine speed, a dedicated control valve for switching the above-described cooling water circuit is necessary. This control valve (three-way valve) is a rotary type valve that rotationally drives the valve body by an actuator such as a servo motor, so that the product cost increases. Further, it is necessary to provide a water temperature sensor dedicated to valve control on the downstream side of the cooling water in the heat storage tank to perform control control of the control valve.

  The present invention has been made in view of such a situation, and in a cooling device incorporating a heat storage device for storing cooling water heated by an internal combustion engine mounted on a vehicle or the like in a heat-retaining state, It is an object of the present invention to provide a technique capable of achieving a heat release function and a heat recovery function for a heat storage device with a simple configuration.

The present invention is a cooling device incorporating a heat storage device (heat storage tank) for storing a part of cooling water heated by an internal combustion engine in a heat-retaining state, and the cooling water is supplied to the internal combustion engine and a heat exchanger (for example, A cooling system for an internal combustion engine, comprising: a first cooling water circuit that circulates via a heater, etc .; a second cooling water circuit that circulates the cooling water via the internal combustion engine and the heat storage device; and a water pump. In such a cooling device, the cooling water outlet of the heat exchanger and the cooling water outlet of the heat storage device communicate with the cooling water inlet of the internal combustion engine, and the first cooling water circuit and the cooling device A water pump having a variable pump discharge pressure is used in combination with the cooling water circulation with the second cooling water circuit without depending on the rotational speed of the internal combustion engine. Further, provided at the cooling water inlet side or the cooling water outlet side of the heat exchanger, the valve is closed when the pump discharge pressure of the water pump is smaller than a first set value (set value α), and the pump discharge pressure is A first valve (for example, a device relief valve 7 ) that opens when the temperature is equal to or higher than the first set value and a cooling water outlet side of the heat storage device, and the coolant temperature is higher than the set value (set value A). When the temperature is lower, the valve is in an open state, and the outlet-side second valve (for example, a heat storage thermostat 9 ) has a response delay from when the coolant temperature reaches or exceeds the set value until the valve is closed (fully closed ). When the heat storage device radiates heat, the outlet-side second valve is open, and when the outlet-side second valve is open, the first valve is closed. Said water pump with pump discharge pressure Is operated to supply high-temperature cooling water stored in the heat storage device to the internal combustion engine .

  According to the present invention, heat discharge from the heat storage device to the internal combustion engine (hereinafter also referred to as hot water supply) and from the internal combustion engine by discharge control of one water pump without using a control valve (three-way valve) or the like. Since heat recovery to the heat storage device (hereinafter also referred to as hot water recovery) is possible, the hot water supply and hot water recovery functions can be realized with a simple configuration. The specific configuration will be described below.

First, in the present invention, the pump discharge pressure ( discharge flow rate ) of the water pump is set so that the outlet-side second valve is open and the first valve is closed when hot water is supplied ( when heat is released ). To control. Specifically, when the first valve is a relief valve and hot water is supplied, the water pump is controlled so that the relief valve is not opened by the pump discharge pressure, so that the high-temperature cooling water ( Hereinafter, the high-temperature water is also supplied to the internal combustion engine side through the outlet-side second valve. By such control, high-temperature water can be supplied from the heat storage device to the internal combustion engine only by discharge control of the water pump. In addition, since the first valve is closed when hot water is supplied (when the engine is started), the flow of cooling water to the heat exchanger (such as a heater) can be shut off. It can be used effectively only for warming up the engine. As a result, warm-up of the internal combustion engine by supplying hot water can be promoted, and fuel consumption and exhaust emission can be improved.

In the present invention, in consideration of the responsiveness of the valve closing against the cooling water temperature at the outlet side second valve, cold water recovered to the heat storage device from the internal combustion engine is completely timing (outlet-side second valve does not flow into the internal combustion engine side If the water pump is stopped at the timing before the valve is closed), the low-temperature water is not mixed with the high-temperature water supplied to the internal combustion engine, so that warm-up due to the operation of the internal combustion engine can be more effectively promoted. When the warm-up of the internal combustion engine is started after such hot water recovery, the water pump that has been stopped is operated according to the engine operation.

In the present invention, after heat dissipation of the heat storage device, the pump discharge pressure ( discharge flow rate ) of the water pump is controlled so that the first valve is opened. By such control, securing of the heater performance after warming up by supplying hot water can be realized only by discharge control of the water pump.

As another configuration of the present invention, a cooling device incorporating a heat storage device for storing a part of cooling water heated by an internal combustion engine in a heat-retaining state, the cooling water being routed through the internal combustion engine and the heat exchanger. In the cooling apparatus for an internal combustion engine, comprising: a first cooling water circuit that is circulated, a second cooling water circuit that circulates the cooling water via the internal combustion engine and the heat storage device, and a water pump. A cooling water outlet of the storage device and a cooling water outlet of the heat storage device communicate with the cooling water inlet of the internal combustion engine, and the internal combustion engine is connected to the cooling water circulation between the first cooling water circuit and the second cooling water circuit. A water pump having a variable pump discharge pressure is used in combination without depending on the rotation speed. Further, provided at the cooling water inlet side or the cooling water outlet side of the heat exchanger, the valve is closed when the pump discharge pressure of the water pump is smaller than a first set value, and the pump discharge pressure is set to the first set value. A first valve (for example, device relief valve 7) that opens when the temperature is equal to or higher than (set value α) and the heat storage device, and the coolant temperature is equal to or higher than the set value (set value A) An internal second valve (for example, a heat storage thermostat 190) that is opened, and when the heat storage device radiates heat, the internal second valve is open, and the internal second valve is open. In addition, by operating the water pump at a pump discharge pressure such that the first valve is closed, high temperature cooling water stored in the heat storage device is supplied to the internal combustion engine. Door can be. Also in the present invention, the water pump is operated at a pump discharge pressure such that the first valve is opened after the heat storage device has released heat .

  Even in this configuration, high-temperature water can be supplied from the heat storage device to the internal combustion engine only by the discharge control of the water pump. In addition, mixing of the high-temperature water supplied to the internal combustion engine and the low-temperature water recovered by the heat storage device during heat dissipation of such a heat storage device can be suppressed.

As a specific configuration of the present invention , the pump is closed when the pump discharge pressure of the water pump is smaller than a second set value (set value β) larger than the first set value (set value α). A third valve (for example, a heat storage relief valve) that opens when the pressure is equal to or higher than the second set value (set value β) is provided in parallel to the outlet-side second valve or the internal second valve; At the time of heat recovery to the heat storage device, the water pump is operated at a pump discharge pressure such that the third valve is opened during operation of the internal combustion engine, thereby cooling water heated by the internal combustion engine. The structure which collect | recovers one part in a thermal storage apparatus can be mentioned.

  According to this structure, the collection | recovery of the high temperature water to a thermal storage apparatus is realizable only by discharge control of a water pump. Further, for example, even when the internal combustion engine is stopped before warming up, it is possible to collect relatively high-temperature cooling water on the internal combustion engine side in the heat storage device by discharge control of the water pump.

In this case, as the outlet-side second valve or the internal second valve provided in the second cooling water circuit (heat storage circuit), a thermostat having a compression coil spring that presses the valve body toward the closing side is used, and the valve body and the compression coil are used. If the relief valve is configured using a spring, the outlet-side second valve or the internal second valve can have the function of the third valve, so that the third valve can be omitted.

  Further, in the present invention, there is provided water temperature storage means for storing the temperature of the cooling water at the time of heat recovery to the heat storage device, the cooling water temperature stored in the water temperature storage means, and the current cooling water temperature during operation of the internal combustion engine. And the heat recovery is executed when the current coolant temperature is equal to or higher than the previously stored coolant temperature. By adopting such a configuration, it is possible to collect the high-temperature water having the highest cooling water temperature in the heat storage device during the operation of the internal combustion engine (between ignition on and ignition off). Thereby, the fuel consumption and exhaust emission at the next driving can be further improved.

  In the present invention, the heat recovery to the heat storage device may be performed in a plurality of times. When such a recovery method is adopted, the temperature of the cooling water in the first cooling water circuit (a circuit for circulating the cooling water via a heat exchanger such as an internal combustion engine and a heater) at the time of heat recovery (at the time of hot water recovery). Can be suppressed. As a result, fuel consumption can be improved, and deterioration of the heater function can be suppressed.

  In addition, when heat recovery (hot water recovery) to the heat storage device is performed in a plurality of times, the heat recovery time is made variable according to the number of times of heat recovery to the heat storage device. For example, when the internal combustion engine is shut down (ignition off), the heat recovery time is set shorter as the number of times heat recovery is performed is increased according to the number of times heat recovery is performed before the operation is stopped. To do. Moreover, you may change 1 time of warm water collection | recovery time according to the frequency | count of implementation of warm water collection | recovery. In this case, for example, a recovery method in which the hot water recovery time at the start of hot water recovery is set short and the hot water recovery time is set longer as the number of hot water recoveries progresses.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Embodiment 1>
FIG. 1 is a schematic configuration diagram showing an example of the cooling device of the present invention.

  The cooling device of this example is a cooling device applied to a vehicle on which the engine 1 is mounted, and includes an electric water pump 2, a radiator 3, an engine thermostat 4, a heater 5, an EGR (Exhaust Gas Recirculation) cooler 6, and a device relief. A valve 7, a heat storage tank 8, a heat storage thermostat 9, a heat storage relief valve 10, and a cooling water circuit 100 for circulating cooling water to these devices are provided.

  The cooling water circuit 100 includes a radiator circuit 101 that circulates cooling water (for example, LLC: Long Life Coolant) through the engine 1, the radiator 3, and the engine thermostat 4, and the cooling water for the engine 1, the heater 5, and the EGR cooler. 6. A heater circuit 102 that circulates through the device relief valve 7 and the engine thermostat 7 and a heat storage circuit 103 that circulates the cooling water through the engine 1, the heat storage tank 8 and the heat storage thermostat 9 are provided. In this example, one electric water pump 2 is used in combination with the cooling water circulation of the radiator circuit 101, the heater circuit 102, and the heat storage circuit 103.

  The electric water pump 2 is a water pump capable of variably setting the discharge flow rate (discharge pressure) by controlling the rotation speed of the electric motor, and the discharge port is a cooling water inlet (an inlet of a water jacket) of the engine 1. ) It is arranged to communicate with 1a.

  The engine thermostat 4 is a valve device that operates, for example, by expansion / contraction of thermowax in the heat sensitive part. When the cooling water temperature is relatively low (when cold), a cooling water passage between the engine 1 and the radiator 3 is used. Is shut off and the cooling water is not allowed to flow through the radiator 3 (the radiator circuit 101), so that the warm-up operation of the engine 1 can be completed early. On the other hand, after the warm-up of the engine 1 is completed, that is, when the cooling water temperature is relatively high, the engine thermostat 4 operates (opens) according to the cooling water temperature, and a part of the cooling water flows to the radiator 3. Thus, the heat recovered by the cooling water is released from the radiator 3 to the atmosphere.

  The heater circuit 102 includes a cooling water supply pipe 121 that supplies the cooling water from the engine 1 to the heater 5 and the EGR cooler 6, and a cooling water return pipe that returns the cooling water that has passed through the heater 5 and the EGR cooler 6 to the engine 1 side. 122 is formed. The cooling water supply pipe 121 is connected to the cooling water outlet 1 b of the engine 1. The cooling water return pipe 122 is connected to the suction port 2a of the electric water pump 2, and the cooling water outlet (cooling water outlet of the heat exchanger) of the heater 5 and the EGR cooler 6 is connected to the cooling water return pipe 122 and the electric water pump. 2 is connected to the cooling water inlet 1 a of the engine 1. A device relief valve 7 and an engine thermostat 4 are disposed in the cooling water reflux pipe 122 in order from the upstream side (upstream side of the cooling water flow).

  The heater 5 is for heating the passenger compartment using the heat of the cooling water, and is disposed facing the air duct of the air conditioner. In other words, during heating of the passenger compartment, the conditioned air flowing in the air duct is passed through the heater 5 and supplied as warm air to the passenger compartment, while in other cases (for example, during cooling), the conditioned air bypasses the heater 5. ing.

  The EGR cooler 6 is a heat exchanger for cooling the EGR gas that is disposed in the EGR passage that recirculates part of the exhaust gas flowing through the exhaust passage of the engine 1 to the intake passage, and that passes through (recirculates) the EGR passage. .

  The device relief valve 7 is closed when the pump discharge pressure Pw [kPa] of the electric water pump 2 is smaller than the set value α (Pw <α), and the pump discharge pressure Pw is not less than the set value α (α ≦ Pw). Sometimes open. When the device relief valve 7 is closed, the cooling water passage (cooling water return pipe 122) between the EGR cooler 6 and the engine thermostat 4 is blocked. The set value α set for the pump discharge pressure Pw is, for example, in consideration of the use range of the discharge flow rate (water pump discharge pressure) of the electric water pump 2 during normal running, and the pump discharge pressure Pw is below the normal running use range. The value is set so that the device relief valve 7 does not open at the pressure of.

  The heat storage tank 8 is a tank having a heat insulating structure that stores the cooling water heated by the engine 1 in a heat-retaining state. An inner pipe 81 extending from the lower part of the tank to the vicinity of the upper part is provided in the heat storage tank 8, and an upper end opening of the inner pipe 81 serves as a cooling water outlet 8b. A cooling water inlet 8 a is provided on the bottom wall of the heat storage tank 8. One end of a cooling water introduction pipe 131 is connected to the cooling water inlet 8 a of the heat storage tank 8. The other end of the cooling water introduction pipe 131 is connected to a cooling water supply pipe 121 on the upstream side of the heater 5 (upstream side of the cooling water flow).

  One end of a cooling water outlet pipe 132 is connected to the inner pipe 81 of the heat storage tank 8, and the cooling water outlet 8 b of the heat storage tank 8 and the cooling water outlet pipe 132 communicate with each other. The other end of the cooling water outlet pipe 132 communicates with the cooling water inlet 2 a of the electric water pump 2, and the cooling water outlet 8 b of the heat storage tank 8 is connected to the engine 1 via the cooling water outlet pipe 132 and the electric water pump 2. It is connected to the cooling water inlet 1a. In addition, a heat storage thermostat 9 is provided in the cooling water outlet pipe 132, and a heat storage relief valve 10 is provided in a bypass pipe 133 that bypasses the heat storage thermostat 9.

  The heat storage thermostat 9 is a valve device that operates, for example, by expansion / contraction of the thermowax in the heat sensitive part, and is open when the cooling water temperature Thw [° C.] is lower than the set value A (Thw <A), and the cooling water temperature Thw. Is closed when A is greater than or equal to the set value A [A ≦ Thw]. The set value A set for the coolant temperature Twh is a temperature (A <B) lower than the operating temperature of the engine thermostat 4 (set value B: 82 ° C., for example), and is circulated in the warm-up process. Even if water contacts the heat sensitive part 93 of the heat storage thermostat 9, a value is set so that the heat storage thermostat 9 does not open at the cooling water temperature.

  In addition, since the thermal storage thermostat 9 is a valve device that operates by expansion / contraction of the thermowax, there is a response delay. For this reason, the thermal storage thermostat 9 is not immediately closed when the cooling water temperature Thw becomes equal to or higher than the set value A, but when the cooling water temperature Thw of the cooling water contacting the heat sensitive part becomes equal to or higher than the set value A. There is a delay time from the time it is completely closed.

  The heat storage relief valve 10 arranged in parallel with the heat storage thermostat 8 is closed when the pump discharge pressure Pw of the electric water pump 2 is smaller than the set value β (Pw <β), and the pump discharge pressure Pw is set to the set value. Open when β is greater than or equal to (β ≦ Pw). When the heat storage relief valve 10 is opened, the cooling water outlet 8 b of the heat storage tank 8 and the suction port 2 a of the electric water pump 2 communicate with each other through the bypass pipe 133. The set value β set for the pump discharge pressure Pw is, for example, in consideration of the upper limit of the use range of the discharge flow rate (discharge pressure) of the electric water pump 2 during normal travel, and the pump discharge flow rate (discharge pressure) during normal travel ), The heat storage relief valve 10 is not opened, and the value is set so that the heat storage relief valve 10 opens when the electric water pump 2 is operated at the maximum discharge flow rate (discharge pressure).

  In the above cooling device, the operation of the electric water pump 2 is controlled by an ECU (Electronic Control Unit) 200. Control of the cooling device of the present invention is realized by a program executed by the ECU 100.

-ECU-
The ECU 200 includes a CPU, a ROM, a RAM, a backup RAM, and the like. The ROM stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU executes arithmetic processing based on various control programs and maps stored in the ROM. The RAM is a memory that temporarily stores calculation results from the CPU, data input from each sensor, and the like. The backup RAM is a non-volatile memory that stores data to be saved when the engine 1 is stopped. is there.

  The ECU 200 is connected to various sensors that detect the operating state of the engine 1, such as a water temperature sensor 11 that detects the temperature (cooling water temperature) of the cooling water flowing through the water jacket of the engine 1. The ECU 200 is connected to an ignition switch 12 for starting the engine.

  Then, the ECU 200 performs various types of the engine 1 including throttle valve opening control, ignition timing control, fuel injection amount control (injector opening / closing control), etc., based on output signals from various sensors that detect engine operating conditions. Execute control. Moreover, ECU200 performs the above-mentioned cooling water circulation control of the cooling device. An example of the control will be described with reference to the flowchart of FIG. The control routine of FIG.

  This control routine is started when the ignition switch 12 is turned on (IG-ON). When the circulating water control routine is started, in step ST101, the electric water pump 2 is operated at a minute flow rate such that the pump discharge pressure Pw is lower than the set value α (Pw <α).

  When the electric water pump 2 is operated (when the engine is started), the temperature of the cooling water in contact with the heat storage thermostat 9 is low (Thw <A), so the heat storage thermostat 9 is open. When the electric water pump 2 is operated at a minute flow rate in this state, as shown in FIG. 3A, the cooling water (low temperature water) from the engine 1 flows into the heat storage tank 8 through the cooling water introduction pipe 131. Accordingly, high-temperature water stored in the heat storage tank 8 (the storage of high-temperature water in the heat storage tank 8 will be described later) flows out to the cooling water outlet pipe 132 through the cooling water outlet 8 b and passes through the heat storage thermostat 9. It is supplied to the water jacket inside the engine 1 later.

  Next, in step ST102, it is determined whether or not a predetermined time ta has elapsed from the time when the operation of the electric water pump 2 is started, and the electric water pump 2 is stopped when the determination result is affirmative (step ST102). ST103).

  Here, the time ta (fixed time) for operating the electric water pump 2 is the time until the low-temperature water existing in the engine 1 is replaced with the high-temperature water from the heat storage tank 8, and the electric water pump The time is set so that the low temperature water does not return to the engine 1 again due to the circulation by 2. Specifically, since the response time until the heat storage thermostat 9 is changed from the open state to the closed state is long, the response delay (time lag) and the volume of the heat storage tank 8 (including the volume of the piping system of the heat storage circuit 103) In consideration, the timing when the high temperature water from the heat storage tank 8 is present in the heat storage thermostat 9 (for example, the high temperature water exists up to the X position in FIG. 3A, and the low temperature water that has passed through the heat storage tank 8 enters the heat storage thermostat 9. The operation time ta of the electric water pump 2 is set so that the closing of the heat storage thermostat 9 is completed at a timing not reached), and the electric water pump 2 is stopped at a timing before the heat storage thermostat 9 is completely closed.

  Then, when the response of the heat storage thermostat 9 is completed and the heat storage thermostat 9 is closed (step ST104 is affirmative determination), the process proceeds to step ST105.

  Thus, by supplying high temperature water from the heat storage tank 8 to the engine 1 and warming the engine 1, the volatility of the fuel can be increased at an early stage, and the ignitability of the air-fuel mixture can be increased. As a result, engine startability at the time of cold start or the like is improved, and fuel efficiency and exhaust emission can be improved. Moreover, by stopping the electric water pump 2 at the above-described timing, it is possible to avoid mixing the high-temperature water supplied to the engine 1 at the time of supplying hot water and the low-temperature water collected in the heat storage device 8.

  Next, after the above hot water supply is completed, in step ST105, the electric water pump 2 is controlled to have a discharge flow rate (pump discharge pressure Pw ≧ α) according to the operating state of the engine 1. The device relief valve 7 is activated (opened) by the control of the electric water pump 2. Here, when the hot water supply is completed, the engine thermostat 4 is closed because the cooling water temperature Thw has not reached the warm-up temperature. Since the heat storage thermostat 9 is also closed, as shown in FIG. 3B, [Electric water pump 2] → [Engine 1] → [Heater 5] → [EGR cooler 6] → [Device relief valve] 7] → [Engine Thermostat 4] → [Electric Water Pump 2], a cooling water circulation circuit (heater circuit 102) is formed, and in the circulation process, the cooling water is heated by the engine 1 and the cooling water temperature rises.

  During the warm-up by such engine operation, the cooling water passage (cooling water outlet pipe 132) between the suction port 2a of the electric water pump 2 and the cooling water outlet 8b of the heat storage tank 8 is blocked by the heat storage thermostat 9. (The bypass pipe 133 is also shut off by the heat storage relief valve 10), so that the low-temperature water accumulated in the heat storage tank 8 in the above-described hot water supply process does not flow out to the heater circuit 102. In addition, the capacity of the cooling water flowing through the heater circuit 102 can be reduced by the amount of the cooling water accumulated in the heat storage tank 8 (including the piping of the heat storage circuit 103). The warm-up can be completed early.

  Then, in this warm-up process, it is determined whether or not the ignition switch 12 is turned off (IG-OFF) (step ST106). If the determination result is affirmative, the process proceeds to step ST114. If the determination result of step ST106 is negative, the process proceeds to step ST107.

  In step ST107, it is determined whether or not the warm-up is completed. Specifically, it is determined whether or not the coolant temperature Thw obtained from the output signal of the water temperature sensor 11 has reached a temperature immediately before the engine thermostat 4 operates (opens) (for example, a temperature immediately before 82 ° C.). If the determination result is affirmative, it is determined that warm-up by engine operation has been completed, and the process proceeds to step ST108. If the determination result of step ST107 is negative, the process returns to step ST105.

  Here, after it is determined that the warm-up has been completed, when the coolant temperature Thw becomes equal to or higher than the operating temperature of the engine thermostat 4 (B ≦ Thw), the vehicle shifts to the normal running state. During this normal running, as shown in FIG. 4A, in addition to the heater circuit 102, [electric water pump 2] → [engine 1] → [radiator 3] → [engine thermostat 4] → [electric water A cooling water circuit of the pump 2] is formed. That is, the radiator circuit 101 is connected in parallel to the heater circuit 102, a part of the cooling water (high temperature water) circulating through the heater circuit 102 flows into the radiator 3, and the heat of the cooling water is released from the radiator 3 to the outside. During normal running, the discharge flow rate is controlled so that the pump discharge pressure Pw of the electric water pump 2 is within the range [α ≦ Pw <β].

  Next, in step ST108, it is determined whether the number n of hot water collections described later is smaller than the set number N (n <N). If the determination result is affirmative, the process proceeds to step ST109. If the determination result of step ST108 is negative, the process proceeds to step ST113.

  In step ST109, it is determined whether or not the cooling water temperature Thw has been stabilized after the previous hot water recovery. Specifically, it waits until a predetermined time elapses from the previous hot water recovery completion time (when the electric water pump 2 is stopped), and determines that the cooling water temperature Thw is stable when the standby time tb elapses. Then, the process proceeds to step ST110.

  In step ST110, the electric water pump 2 is operated at the maximum flow rate (pump discharge pressure Pw ≧ β). With the operation of the electric water pump 2 as described above, the heat storage relief valve 10 is opened, and as shown in FIG. 4B, in addition to the heater circuit 102, [electric water pump 2] → [engine 1] → A cooling water circuit of [heat storage tank 8] → [heat storage relief valve 10] → [electric water pump 2] is formed. That is, since the heat storage circuit 103 is connected in parallel to the heater circuit 102, a part of the cooling water (high temperature water) circulating through the heater circuit 102 is supplied from the engine 1 to the heat storage tank 8, and the hot water is stored in the heat storage tank 8. Collected.

  At the time of such hot water recovery, when the cooling water temperature Thw is equal to or higher than the operating temperature of the engine thermostat 4 (set value B: 82 ° C., for example), as shown by the dashed arrow in FIG. A part of the cooling water (hot water) from the engine 1 also flows to the radiator 3.

  Next, in step ST111, it is determined whether or not a certain period of time (warm water recovery time [T1 / N]) has elapsed since the start of hot water recovery. When the determination result is affirmative, the nth warm water is determined. It determines with collection having been completed, and progresses to step ST112.

  Here, the “warm water recovery count” used in the determination process of step ST108, the “hot water recovery time” used in the determination process of step ST111, the standby time tb used in the determination process of step ST109, and the determination process of step ST116 described below The “hot water recovery time during IG-OFF” to be used will be described with reference to FIG.

-Number of hot water recovery and hot water recovery time-
First, when the cold / hot water exchange between the low temperature water in the heat storage tank 8 and the high temperature water in the engine 1 is performed at a time with the electric water pump 2 operating at the maximum discharge flow rate, the electric water pump 2 flows into the engine 1 and the heater circuit 102. The temperature of the cooling water decreases, which may adversely affect the engine operation and the heater function.

  In order to solve this, in this example, the hot water recovery is performed in N times. Specifically, if T1 time is required to replace the low-temperature water in the heat storage tank 8 with high-temperature water, it is set as one hot water recovery time [T1 / N], and N times in the heat storage tank 8 All of the cooling water can be exchanged with hot water from the engine 1 (see FIG. 5).

  By dividing the hot water recovery into N times in this way, it is possible to prevent the temperature of the cooling water flowing through the engine 1 and the heater circuit 102 from rapidly decreasing. As a result, fuel consumption can be improved, and a decrease in heater function can be suppressed. However, if the hot water recovery is to be executed after the number of times of hot water recovery is N times or more (after the determination result of step ST108 is negative), in step ST111 The hot / cold water exchange between the low-temperature water in the heat storage tank 8 and the high-temperature water in the engine 1 is performed at a time with the hot water recovery time of T1 (see FIG. 5).

-Standby time-
When the hot water recovery is executed in N times, if the interval from the end of the previous hot water recovery to the start of the current hot water recovery is short, the above-described effect of suppressing the cooling water temperature decrease is reduced. Considering this point, every time n-th warm water recovery is completed, a waiting time Tb from the completion of the n-th warm water recovery until the cooling water temperature Thw is stabilized is provided. The standby time tb is a value obtained by performing experiments and calculations in advance to obtain a time until the cooling water temperature Thw is stabilized after performing the hot water recovery at the hot water recovery time [T1 / N]. Set.

-Hot water recovery time at IG-OFF-
The hot water recovery time Toff at the time of IG-OFF is the number of times hot water recovery is performed at the hot water recovery time [T1 / N] until the operation is stopped when the operation of the engine 1 is stopped (the number n of hot water recovery times). ). Specifically, as shown in FIG. 5, when the number of hot water recovery times is 1 (n = 1), 2 times (n = 2)... N times, the hot water recovery time Toff at the time of IG-OFF is set to [(N−1) / N × T1], [(N−2) / N × T1]... [(N−n) / N × T1]. However, the collection time is set to “0” when the number n of hot water collections at the time of IG-OFF is N or more (N ≦ n). Note that the hot water recovery time Toff shown in FIG. 5 may be stored in the ROM of the ECU 200 as a map of the hot water recovery frequency n as a parameter.

  In step ST112, the current cooling water temperature is read from the output signal of the water temperature sensor 11, and the cooling water temperature (recovered water temperature) is stored in the RAM of the ECU 200 or the like. This cooling water temperature is sequentially stored and updated to the latest value. Further, in step ST112, the hot water collection number n is stored in the RAM of the ECU 200 or the like. The number n of hot water collections is incremented (n ← n + 1) every time hot water collection is executed (see FIG. 5). The number n of hot water collections is initialized (n ← 0) when IG-OFF.

  In this way, the hot water recovery at the hot water recovery time [T1 / N] is sequentially repeated, and when the number of executions n reaches N (n ≧ N), the determination result of step ST108 is negative, and the step Proceed to ST113.

  In step ST113, the current cooling water temperature Thw is read from the output signal of the water temperature sensor 11, and it is determined whether or not the current cooling water temperature Thw is larger than the cooling water temperature stored last time by the process in step ST112. If the result is affirmative, warm water recovery is executed (step ST110). Since this hot water recovery is [N + 1] th, the hot water recovery is executed at the hot water recovery time T1 (see FIG. 5). On the other hand, when the current coolant temperature Thw is lower than the previously stored coolant temperature (determination result in step ST113 is negative), the process returns to step ST107 and enters a standby state. During this standby state, the current coolant temperature Thw is When the cooling water temperature is equal to or higher than the previously stored cooling water temperature, the hot water is recovered at the hot water recovery time T1.

  By performing the hot water recovery in such a process, the hot water having the highest cooling water temperature Thw is recovered (stored) in the heat storage tank 8 during the operation of the engine 1 (between IG-ON and IG-OFF). )can do.

  On the other hand, when the determination result in step ST106 is affirmative (when IG-OFF is set), it is determined in step ST114 whether the number n of hot water collections is less than N. If the determination result in step ST114 is affirmative, the warm water recovery is not completed in the warm water recovery time [T1 / N], so the warm water recovery is executed in step ST115.

  Specifically, when IG-OFF (engine operation is stopped), the number n of hot water collections in which hot water collection is performed in the warm water collection time [T1 / N] until the IG-OFF time (step ST112). The hot water recovery time Toff at the time of IG-OFF is obtained from the table (map) shown in FIG. 5 on the basis of the latest hot water recovery frequency n) stored in, and the maximum flow rate of the electric water pump 2 is determined based on the hot water recovery time Toff. It operates at (pump discharge pressure Pw ≧ β) and executes hot water recovery. By performing such warm water recovery, all the cooling water in the heat storage tank 8 can be replaced with high temperature water even if IG-OFF (engine operation stop) occurs during the warm water recovery.

  If the engine is warmed up during engine operation (ie, the number of times hot water is recovered n = 0), the hot water is recovered at the hot water recovery time T1, and the hot water on the engine 1 side is recovered in the heat storage tank 8. (Store). At this time, since hot water is recovered at a temperature immediately before the engine thermostat 4 is actuated (opened) (immediately before radiator radiation), even if the operation of the engine 1 is stopped before completely warming up, Relatively hot water can be recovered. Thereby, it is possible to improve the fuel consumption and exhaust emission at the next driving.

  On the other hand, when the determination result in step ST114 is negative, hot water recovery during the hot water recovery time [T1 / N] has been performed N times or more (n ≧ N), and all cooling in the heat storage tank 8 has been performed. Since the water has been replaced with hot water, this control routine is terminated.

  As described above, according to this example, the hot water supply from the heat storage tank 8 to the engine 1 and the hot water recovery to the heat storage tank 8 of the engine 1 can be performed by the discharge control of one electric water pump 2. The hot water supply and hot water recovery functions can be realized with a simple configuration.

  In this example, as the heat storage thermostat 9, for example, a heat storage thermostat 90 having a structure shown in FIG. In this case, the pressure (pump discharge pressure Pw) that the valve body 91 of the heat storage thermostat 90 opens against the elastic force of the first compression coil spring 94 is the water pump discharge that opens the heat storage relief valve 10 when the hot water is recovered. As a value higher than the pressure (set value β), the heat storage thermostat 9 is maintained closed even when the heat storage relief valve 10 is opened, and when the pump discharge pressure Pw is larger than the set value β by a predetermined value. The heat storage thermostat 9 is set to open.

  In the above example, when the hot water recovery is performed in N times, one hot water recovery time [T1 / N] is set to a fixed time, but the present invention is not limited to this, and one hot water recovery is performed. You may change time according to the implementation frequency of warm water collection | recovery. In this case, for example, a recovery method in which the hot water recovery time at the start of hot water recovery is set short and the hot water recovery time is set longer as the number of hot water recoveries progresses.

<Embodiment 2>
Next, another example of the cooling device of the present invention will be described with reference to FIG.

  In the cooling device of this example, the cooling water introduction pipe 131a of the heat storage circuit 103 is connected to the cooling water recirculation pipe 122 on the downstream side of the EGR cooler 6 (downstream side of the cooling water flow) with respect to the above-described first embodiment. The other points are basically the same as the above-described <Embodiment 1>.

  Also in this example, the ECU 200 performs the processing of <Embodiment 1> described above based on the output signal of the water temperature sensor 11 and the operation signal (ON / OFF signal) of the ignition switch 12, that is, FIG. Circulating water control is executed by the same processing as in steps ST101 to ST116. The circulating water control (each control at the time of hot water supply, warm-up process, travel traveling, and hot water recovery) will be described with reference to FIGS.

-When supplying hot water-
At the time of supplying hot water, the heat storage thermostat 9 is in an open state (Thw <A), and in this state, the electric water pump 2 is set to a pressure (Pw <α) where the pump discharge pressure Pw is smaller than the set value α. It operates with such a small flow rate. By the operation of the electric water pump 2, as shown in FIG. 7A, the low temperature water from the engine 1 passes through the heater 5, the EGR cooler 6 and the cooling water introduction pipe 131a and flows into the heat storage tank 8. Along with this, the high temperature water stored in the heat storage tank 8 (the storage of the high temperature water in the heat storage tank 8 will be described later) flows out from the cooling water outlet 8b of the heat storage tank 8 to the cooling water outlet pipe 132 to store heat. After passing through the thermostat 9, it flows into the water jacket inside the engine 1.

  Thus, by supplying high temperature water from the heat storage tank 8 to the engine 1 and warming the engine 1, the volatility of the fuel can be increased at an early stage, and the ignitability of the air-fuel mixture can be increased. As a result, engine startability at the time of cold start or the like is improved, and fuel efficiency and exhaust emission can be improved.

  Also in this example, similarly to the above-described <Embodiment 1>, the operation time ta of the electric water pump at the time of supplying hot water is the response delay of the heat storage thermostat 9 and the volume of the heat storage tank 8 (the piping of the heat storage circuit 103). In consideration of the system volume), a time is set so that the closing of the heat storage thermostat 9 is completed at a timing when the high temperature water from the heat storage tank 8 is present in the heat storage thermostat 9. By stopping the electric water pump 2 at such timing, it is possible to avoid mixing the high-temperature water supplied to the engine 1 during the supply of hot water and the low-temperature water recovered by the heat storage device 8.

-Warm-up process-
After the above hot water supply is completed, the electric water pump 2 is controlled to have a discharge flow rate (pump discharge pressure Pw ≧ α) corresponding to the operating state of the engine 1. The device relief valve 7 is actuated (opened) by the control of the electric water pump 2. Here, when the hot water supply is completed, the engine thermostat 4 is closed because the cooling water temperature Thw has not reached the warm-up temperature. Since the heat storage thermostat 9 is also closed, as shown in FIG. 7B, [Electric water pump 2] → [Engine 1] → [Heater 5] → [EGR cooler 6] → [Device relief valve] 7] → [Engine thermostat 4] → [Electric water pump 2] cooling water circuit (heater circuit 102) is formed, and in the circulation process, the cooling water is heated by the engine 1 and the cooling water temperature rises.

  During the warm-up by such engine operation, the cooling water passage (cooling water outlet pipe 132) between the suction port 2a of the electric water pump 2 and the cooling water outlet 8b of the heat storage tank 8 is blocked by the heat storage thermostat 9. Therefore, the low-temperature water accumulated in the heat storage tank 8 in the above-described hot water supply process does not flow out to the heater circuit 102. In addition, the capacity of the cooling water flowing through the heater circuit 102 can be reduced by the amount of the cooling water accumulated in the heat storage tank 8 (including the piping of the heat storage circuit 103). The warm-up can be completed early.

-During normal driving-
During normal traveling, as shown in FIG. 8A, in addition to the heater circuit 102, [electric water pump 2] → [engine 1] → [radiator 3] → [engine thermostat 4] → [electric water pump 2] The cooling water circuit is formed. That is, the radiator circuit 101 is connected in parallel to the heater circuit 102, a part of the cooling water (high temperature water) circulating through the heater circuit 102 flows into the radiator 3, and the heat of the cooling water is released from the radiator 3 to the outside. During normal running, the discharge flow rate is controlled so that the pump discharge pressure Pw of the electric water pump 2 is within the range [α ≦ Pw <β].

-When recovering hot water-
At the time of hot water recovery, the electric water pump 2 is operated at the maximum flow rate (pump discharge pressure Pw ≧ β). The heat storage relief valve 10 is opened by such an operation of the electric water pump 2. As a result, as shown in FIG. 8B, the low temperature water from the heat storage tank 8 flows into the engine 1 after passing through the heat storage relief valve 10, and accordingly, the high temperature water on the engine 1 side becomes the heater 5 and After passing through the EGR cooler 6, it flows into the heat storage tank 8 and high temperature water is recovered in the heat storage tank 8.

  It should be noted that when the cooling water temperature Thw is equal to or higher than the operating temperature of the engine thermostat 4 (for example, 82 ° C.) at the time of this hot water recovery, as shown by the dashed arrow in FIG. A part of the hot water also flows to the radiator 3.

  Also in this example, as in the above-described <Embodiment 1>, at the time of hot water recovery, the cold / hot water exchange between the low temperature water in the heat storage tank 8 and the high temperature water in the engine 1 is not performed at a time, By performing the hot water recovery in N times, the temperature of the cooling water flowing through the engine 1 and the heater circuit 102 is prevented from rapidly decreasing, and the fuel consumption and the heater function are improved.

  Further, after the number of times of hot water recovery becomes N times or more and the current cooling water temperature Thw becomes equal to or higher than the previously stored cooling water temperature during engine operation, the hot water at the hot water recovery time T1 (see FIG. 5). By the recovery (one-time warm water recovery), the high-temperature water on the engine 1 side is recovered in the heat storage tank 8 (see steps ST113 and ST110 to ST112 in FIG. 2). By performing the hot water recovery in such a process, the hot water having the highest cooling water temperature Thw is recovered (stored) in the heat storage tank 8 during the operation of the engine 1 (between IG-ON and IG-OFF). )can do.

  In addition, when IG-OFF (engine stoppage) occurs during hot water recovery, the number n of hot water recovery times (the latest hot water is recovered) during the hot water recovery time [T1 / N] until the IG-OFF. Using the number of times of recovery n), the hot water recovery time Toff described above is obtained based on the number of times of hot water recovery n, and hot water recovery is performed at the temperature of the hot water recovery time Toff (see steps ST114 to ST116 in FIG. 2). By performing such warm water recovery, all the cooling water in the heat storage tank 8 can be replaced with high temperature water even if IG-OFF (engine operation stop) occurs during the warm water recovery.

  In addition, when the engine is warmed up during operation of the engine and becomes IG-OFF (warm water recovery number n = 0), the hot water recovery is executed with the hot water recovery time Toff, and the relatively hot water on the engine 1 side is stored in the heat storage tank. 8 is collected (stored).

  As described above, also in this example, the hot water supply from the heat storage tank 8 to the engine 1 and the hot water recovery to the heat storage tank 8 of the engine 1 can be performed by the discharge control of one electric water pump 2. Therefore, the hot water supply and hot water recovery functions can be realized with a simple configuration.

  In the above example, when the hot water recovery is performed in N times, one hot water recovery time [T1 / N] is set to a fixed time. However, the present invention is not limited to this, and one hot water recovery is performed. You may change time according to the implementation frequency of warm water collection | recovery. In this case, for example, a recovery method in which the hot water recovery time at the start of hot water recovery is set short and the hot water recovery time is set longer as the number of hot water recoveries progresses.

<Embodiment 3>
Next, another example of the cooling device of the present invention will be described with reference to FIG.

  The cooling device of this example omits the heat storage relief valve 10 from the cooling device of <Embodiment 1> described above, and the function of the heat storage relief valve 10 is the same as the valve body 91 of the heat storage thermostat 90 and the first compression coil spring. It is characterized in that 94 (see FIG. 10) is substituted.

  A heat storage thermostat 90 used in the cooling device of this example will be described with reference to FIGS.

  The heat storage thermostat 90 of this example includes a valve body 91, an operating rod 92, a temperature sensing portion 93, a first compression coil spring 94, a rod holding member 95, a second compression coil spring 96, a spring support plate 97, and a cylindrical shape. A housing 90h is provided.

  The housing 90h is provided with a cooling water inlet 90a and a cooling water outlet 90b. The inner surface of the vertical wall on the cooling water inlet 90a side of the housing 90h serves as a valve seat 90c, and a valve body 91 is disposed opposite to the valve seat 90c. The valve body 91 is movably supported by an operating rod 92 disposed along the axis of the housing 90h.

  A stopper 92 a for preventing the valve body 91 from coming off is provided at one end of the operating rod 92 (end on the cooling water inlet 90 a side). The other end of the operation rod 92 is connected to a case 93a of a temperature sensing unit 93 described later. A first compression coil spring 94 is sandwiched between one end surface of the case 93a (surface on the cooling water inlet 90a side) and the valve body 91, and the valve body 91 is biased toward the stopper 92a.

  An operating plate 93e is fixed to the other end of the case 93a of the temperature sensing portion 93 (the end on the cooling water outlet 90b side). A spring support plate 97 is disposed between the operation plate 93e and the valve body 91. A second compression coil spring 96 is sandwiched between the spring support plate 97 and the operating plate 93e of the temperature sensing section 93, and the entire temperature sensing section 93 is cooled by the elastic force of the second compression coil spring 96. It is biased toward the outlet 90b. Further, a rod holding member 95 is provided between the temperature sensing part 93 and the cooling water outlet 90b. The rod holding member 95 and the spring support plate 97 are fixed to the housing 90h. The rod holding member 95 and the spring support plate 97 are processed into a shape that does not hinder the flow of cooling water.

  The temperature sensing part 93 includes a cylindrical case 93a and a piston rod 93b. The piston rod 93b is slidably disposed on the case 93a. The tip of the piston rod 93 b is inserted into the holding hole 95 a of the rod holding member 95. The case 93a is filled with a thermowax 93c that expands and contracts due to a change in cooling water temperature, and the expansion and contraction of the thermowax 93c changes the amount of protrusion of the piston rod 93b with respect to the case 93a. Yes. The thermowax 93c is accommodated in a sealing material 93d made of rubber or the like.

  In the heat storage thermostat 90 having the above structure, when the cooling water temperature Thw of the cooling water contacting the temperature sensing portion 93 is lower than the set value A described in <Embodiment 1> (Thw <A), the thermowax 93c is The amount of protrusion of the piston rod 93b from the case 93a is reduced, and the entire temperature sensing portion 93 (including the operation rod 92) is moved toward the cooling water outlet 90b by the elastic force of the second compression coil spring 96. . As a result, the valve body 91 is separated from the valve seat 90c and is opened (FIG. 10 (a)). From this state, when the cooling water temperature Thw of the cooling water that contacts the temperature sensing unit 93 is equal to or higher than the set value A (A ≦ Thw), the thermowax 93c expands. Due to the expansion of the thermowax 93c, the protruding amount of the piston rod 93b from the case 93a increases, and the entire temperature sensing portion 93 (including the operation rod 92) moves toward the cooling water inlet 90a. As a result, the valve body 91 is seated on the valve seat 90c and is closed (FIG. 10B).

  As described above, the heat storage thermostat 90 in this example is in the valve open state when the cooling water temperature Thw of the cooling water contacting the temperature sensing unit 93 is lower than the set value A, and the cooling water of the heat storage tank 8 shown in FIG. The outlet 8b and the cooling water inlet 1a of the engine 1 (suction port 2a of the electric water pump 2) communicate with each other. On the other hand, when the cooling temperature Thw becomes equal to or higher than the set value A, the heat storage thermostat 90 is closed, and the cooling water outlet pipe 132 between the cooling water outlet 8b of the heat storage tank 8 and the cooling water inlet 1a of the engine 1 is provided. Blocked.

  Moreover, in the heat storage thermostat 90 of this example, even if the cooling temperature Thw is not less than the set value A (A ≦ Tw) and the valve is closed, the pump discharge pressure Pw of the electric water pump 2 is the above <Embodiment 1>. When the value is equal to or greater than the set value β described in (β ≦ Pw), the valve body 91 moves toward the cooling water outlet 90b against the elastic force of the first compression coil spring 94. As a result, the heat storage thermostat 90 is opened (valve opened) from the valve seat 90c (FIG. 10C), and the cooling water outlet 8b of the heat storage tank 8 and the cooling water of the engine 1 shown in FIG. The inlet 1a communicates.

  Also in this example, the ECU 200 performs the processing of <Embodiment 1> described above based on the output signal of the water temperature sensor 11 and the operation signal (ON / OFF signal) of the ignition switch 12, that is, FIG. Circulating water control is executed by the same processing as in steps ST101 to ST116. The circulating water control (each control at the time of hot water supply, warm-up process, travel traveling, and hot water recovery) will be described with reference to FIGS.

-When supplying hot water-
At the time of hot water supply, the temperature of the cooling water that contacts the temperature sensing portion 93 of the heat storage thermostat 90 is low (cooling water temperature Thw <A), and the heat storage thermostat 90 is open (FIG. 10A). In this state, the electric water pump 2 is operated at a minute flow rate such that the pump discharge pressure Pw becomes a pressure (Pw <α) smaller than the set value α described in the above <Embodiment 1>. By the operation of the electric water pump 2, as shown in FIG. 11A, the cooling water (low temperature water) from the engine 1 flows into the heat storage tank 8 through the cooling water introduction pipe 131, and accordingly, the heat storage tank. 8 is stored in the heat storage tank 8 (which will be described later) after flowing out from the cooling water outlet 8b of the heat storage tank 8 to the cooling water outlet pipe 132 and passing through the heat storage thermostat 90. It flows into the water jacket inside the engine 1.

  Thus, by supplying high temperature water from the heat storage tank 8 to the engine 1 and warming the engine 1, the volatility of the fuel can be increased at an early stage, and the ignitability of the air-fuel mixture can be increased. As a result, engine startability at the time of cold start or the like is improved, and fuel efficiency and exhaust emission can be improved.

  Also in this example, similarly to the above-described <Embodiment 1>, the operation time ta of the electric water pump 2 at the time of supplying hot water is the response delay of the heat storage thermostat 90 and the volume of the heat storage tank 8 (of the heat storage circuit 103). In consideration of the fact that the volume of the piping system is also included), a time is set so that the closing of the heat storage thermostat 90 is completed at the timing when the high temperature water from the heat storage tank 8 is present in the heat storage thermostat 90. By stopping the electric water pump 2 at such timing, it is possible to avoid mixing the high-temperature water supplied to the engine 1 during the supply of hot water and the low-temperature water recovered by the heat storage device 8.

-Warm-up process-
After the above hot water supply is completed, the electric water pump 2 is controlled to have a discharge flow rate corresponding to the operating state of the engine 1. Here, when the hot water supply is completed, the engine thermostat 4 is closed because the cooling water temperature Thw has not reached the warm-up temperature. Since the heat storage thermostat 90 is also closed, as shown in FIG. 11B, [Electric water pump 2] → [Engine 1] → [Heater 5] → [EGR cooler 6] → [Device relief valve] 7] → [Engine thermostat 4] → [Electric water pump 2] cooling water circuit (heater circuit 102) is formed, and in the circulation process, the cooling water is heated by the engine 1 and the cooling water temperature rises.

  During warm-up by such engine operation, a cooling water passage (cooling water outlet pipe 132) between the suction port 2a of the electric water pump 2 and the cooling water outlet 8b of the heat storage tank 8 is formed by the heat storage thermostat 90. Since it is shut off, the low-temperature water accumulated in the heat storage tank 8 in the above-described hot water supply process does not flow out to the heater circuit 102. In addition, the capacity of the cooling water flowing through the heater circuit 102 can be reduced by the amount of the cooling water accumulated in the heat storage tank 8 (including the piping of the heat storage circuit 103). The warm-up can be completed early.

-During normal driving-
During normal traveling, as shown in FIG. 12A, in addition to the heater circuit 102, [electric water pump 2] → [engine 1] → [radiator 3] → [engine thermostat 4] → [electric water pump 2] The cooling water circuit is formed. That is, the radiator 3 is connected in parallel to the heater circuit 102, and a part of the cooling water (high temperature water) circulating through the heater circuit 102 flows into the radiator 3, and the heat of the cooling water is released from the radiator 3 to the outside. During normal running, the discharge flow rate is controlled so that the pump discharge pressure Pw of the electric water pump 2 is within the range [α ≦ Pw <β].

-When recovering hot water-
At the time of hot water recovery, the electric water pump 2 is operated at the maximum flow rate (pump discharge pressure Pw ≧ β). The heat storage thermostat 90 is opened by the operation of the electric water pump 2 (FIG. 10C). Thereby, as shown in FIG. 12B, the low temperature water from the heat storage tank 8 flows into the engine 1 after passing through the heat storage thermostat 90, and a part of the high temperature water on the engine 1 side is cooled accordingly. The hot water is recovered into the heat storage tank 8 by flowing into the heat storage tank 8 through the water introduction pipe 131.

  When the cooling water temperature Thw at the time of such hot water recovery is equal to or higher than the operating temperature of the engine thermostat 4 (for example, 82 ° C.), the cooling from the engine 1 is performed as indicated by the dashed arrow in FIG. Part of the water (hot water) also flows into the radiator 3.

  Also in this example, as in the above-described <Embodiment 1>, at the time of hot water recovery, the cold / hot water exchange between the low temperature water in the heat storage tank 8 and the high temperature water in the engine 1 is not performed at a time, By performing the hot water recovery in N times, the temperature of the cooling water flowing through the engine 1 and the heater circuit 102 is prevented from rapidly decreasing, and the fuel consumption and the heater function are improved.

  Further, after the number of times of hot water recovery becomes N times or more and the current cooling water temperature Thw becomes equal to or higher than the previously stored cooling water temperature during engine operation, the hot water at the hot water recovery time T1 (see FIG. 5). By the recovery (one-time warm water recovery), the high-temperature water on the engine 1 side is recovered in the heat storage tank 8 (see steps ST113 and ST110 to ST112 in FIG. 2). By performing the hot water recovery in such a process, the hot water having the highest cooling water temperature Thw is recovered (stored) in the heat storage tank 8 during the operation of the engine 1 (between IG-ON and IG-OFF). )can do.

  In addition, when IG-OFF (engine stoppage) occurs during hot water recovery, the number n of hot water recovery times (the latest hot water is recovered) during the hot water recovery time [T1 / N] until the IG-OFF. Using the number of times of recovery n), the hot water recovery time Toff described above is obtained based on the number of times of hot water recovery n, and hot water recovery is performed at the temperature of the hot water recovery time Toff (see steps ST114 to ST116 in FIG. 2). By performing such warm water recovery, all the cooling water in the heat storage tank 8 can be replaced with high temperature water even if IG-OFF (engine operation stop) occurs during the warm water recovery.

  If the engine is warmed up during engine operation and becomes IG-OFF (when the number of times hot water is recovered n = 0), the hot water is recovered during the hot water recovery time Toff and the relatively hot water on the engine 1 side is removed. It is recovered (stored) in the heat storage tank 8.

  As described above, also in this example, the hot water supply from the heat storage tank 8 to the engine 1 and the hot water recovery to the heat storage tank 8 of the engine 1 can be performed by the discharge control of one electric water pump 2. Therefore, the hot water supply and hot water recovery functions can be realized with a simple configuration.

  In the above example, when the hot water recovery is performed in N times, one hot water recovery time [T1 / N] is set to a fixed time. However, the present invention is not limited to this, and one hot water recovery is performed. You may change time according to the implementation frequency of warm water collection | recovery. In this case, for example, a recovery method in which the hot water recovery time at the start of hot water recovery is set short and the hot water recovery time is set longer as the number of hot water recoveries progresses.

<Embodiment 4>
Next, another example of the cooling device of the present invention will be described with reference to FIGS.

  In the cooling device of this example, the cooling water introduction pipe 131a of the heat storage circuit 103 is connected to the cooling water recirculation pipe 122 on the downstream side of the EGR cooler 6 (downstream side of the cooling water flow) with respect to the above-described third embodiment. In other respects, the other configuration is basically the same as the above-described <Embodiment 3>.

  Also in this example, the ECU 200 performs the processing of <Embodiment 1> described above based on the output signal of the water temperature sensor 11 and the operation signal (ON / OFF signal) of the ignition switch 12, that is, FIG. Circulating water control is executed by the same processing as in steps ST101 to ST116. The circulating water control (each control during warm water supply, warm-up process, travel traveling, and hot water recovery) will be described with reference to FIGS.

-When supplying hot water-
At the time of supplying hot water, the heat storage thermostat 90 is in an open state, and in this state, the electric water pump 2 is operated at a pressure (Pw <α) where the pump discharge pressure Pw is smaller than the set value α described in the above <First Embodiment>. ) With a minute flow rate such that By the operation of the electric water pump 2, as shown in FIG. 14A, low temperature water from the engine 1 passes through the heater 5, the EGR cooler 6, and the cooling water introduction pipe 131a and flows into the heat storage tank 8. Along with this, high-temperature water stored in the heat storage tank 8 (storage of high-temperature water in the heat storage tank 8 will be described later) flows out to the cooling water outlet pipe 132 through the cooling water outlet 8b and passes through the heat storage thermostat 90. After that, it is supplied to the water jacket inside the engine 1.

  Thus, by supplying high temperature water from the heat storage tank 8 to the engine 1 and warming the engine 1, the volatility of the fuel can be increased at an early stage, and the ignitability of the air-fuel mixture can be increased. As a result, engine startability at the time of cold start or the like is improved, and fuel efficiency and exhaust emission can be improved.

  Also in this example, similarly to the above-described <Embodiment 1>, the operation time ta of the electric water pump 2 at the time of supplying hot water is the response delay of the heat storage thermostat 90 and the volume of the heat storage tank 8 (of the heat storage circuit 103). In consideration of the fact that the volume of the piping system is also included), a time is set so that the closing of the heat storage thermostat 90 is completed at the timing when the high temperature water from the heat storage tank 8 is present in the heat storage thermostat 90. By stopping the electric water pump 2 at such timing, it is possible to avoid mixing the high-temperature water supplied to the engine 1 during the supply of hot water and the low-temperature water recovered by the heat storage device 8.

-Warm-up process-
After the above hot water supply is completed, the electric water pump 2 is controlled to have a discharge flow rate corresponding to the operating state of the engine 1. Here, when the hot water supply is completed, the engine thermostat 4 is closed because the cooling water temperature Thw has not reached the warm-up temperature. Since the heat storage thermostat 90 is also closed, as shown in FIG. 14 (b), [Electric water pump 2] → [Engine 1] → [Heater 5] → [EGR cooler 6] → [Device relief valve] 7] → [Engine Thermostat 4] → [Electric Water Pump 2], a cooling water circulation path (heater circuit 102) is formed. In the circulation process, the cooling water is heated by the engine 1 and the cooling water temperature rises.

  During such warming up by engine operation, the cooling water passage (cooling water outlet pipe 132) between the suction port 2a of the electric water pump 2 and the cooling water outlet 8b of the heat storage tank 8 is blocked by the heat storage thermostat 90. Therefore, the low-temperature water accumulated in the heat storage tank 8 in the above-described hot water supply process does not flow out to the heater circuit 102. Moreover, the capacity of the cooling water flowing through the heater circuit 102 can be reduced by the amount of the cooling water accumulated in the heat storage tank 8 (including the piping of the heat storage circuit 103). And warm-up can be completed early.

-During normal driving-
During normal travel, as shown in FIG. 15A, in addition to the heater circuit 102, [electric water pump 2] → [engine 1] → [radiator 3] → [engine thermostat 4] → [electric water pump 2] The cooling water circulation path is formed. That is, the radiator circuit 101 is connected in parallel to the heater circuit 102, a part of the cooling water (high temperature water) circulating through the heater circuit 102 flows into the radiator 3, and the heat of the cooling water is released from the radiator 3 to the outside. During normal running, the discharge flow rate is controlled so that the pump discharge pressure Pw of the electric water pump 2 is within the range [α ≦ Pw <β].

-When recovering hot water-
At the time of hot water recovery, the electric water pump 2 is operated at the maximum flow rate (pump discharge pressure Pw ≧ β). The operation of the electric water pump 2 opens the heat storage thermostat 90 (FIG. 10C). As a result, as shown in FIG. 15B, the low temperature water from the heat storage tank 8 flows into the engine 1 after passing through the heat storage thermostat 90, and accordingly, the high temperature water on the engine 1 side becomes the heater 5 and EGR. After passing through the cooler 6, it flows into the heat storage tank 8, and high-temperature water is recovered in the heat storage tank 8.

  It should be noted that when the cooling water temperature Thw is equal to or higher than the operating temperature of the engine thermostat 4 (for example, 82 ° C.) during the recovery of the hot water, the cooling water (from the engine 1 ( A part of the hot water also flows to the radiator 3.

  Also in this example, as in the above-described <Embodiment 1>, at the time of hot water recovery, the cold / hot water exchange between the low temperature water in the heat storage tank 8 and the high temperature water in the engine 1 is not performed at a time, By performing the hot water recovery in N times, the temperature of the cooling water flowing through the engine 1 and the heater circuit 102 is prevented from rapidly decreasing, and the fuel consumption and the heater function are improved.

  Further, after the number of times of hot water recovery becomes N times or more and the current cooling water temperature Thw becomes equal to or higher than the previously stored cooling water temperature during engine operation, the hot water at the hot water recovery time T1 (see FIG. 5). By the recovery (one-time warm water recovery), the high-temperature water on the engine 1 side is recovered in the heat storage tank 8 (see steps ST113 and ST110 to ST112 in FIG. 2). By performing the hot water recovery in such a process, the hot water having the highest cooling water temperature Thw is recovered (stored) in the heat storage tank 8 during the operation of the engine 1 (between IG-ON and IG-OFF). )can do.

  In addition, when IG-OFF (engine stoppage) occurs during hot water recovery, the number n of hot water recovery times (the latest hot water is recovered) during the hot water recovery time [T1 / N] until the IG-OFF. Using the number of times of recovery n), the hot water recovery time Toff described above is obtained based on the number of times of hot water recovery n, and hot water recovery is performed at the temperature of the hot water recovery time Toff (see steps ST114 to ST116 in FIG. 2). By performing such warm water recovery, all the cooling water in the heat storage tank 8 can be replaced with high temperature water even if IG-OFF (engine operation stop) occurs during the warm water recovery.

  In addition, when the engine is warmed up during engine operation and becomes IG-OFF (when the number of times hot water is recovered n = 0), warm water is recovered at the warm water recovery time T1, and relatively hot water on the engine 1 side is removed. It is recovered (stored) in the heat storage tank 8.

  As described above, also in this example, the hot water supply from the heat storage tank 8 to the engine 1 and the hot water recovery to the heat storage tank 8 of the engine 1 can be performed by the discharge control of one electric water pump 2. Therefore, the hot water supply and hot water recovery functions can be realized with a simple configuration.

  In the above example, when the hot water recovery is performed in N times, one hot water recovery time [T1 / N] is set to a fixed time. However, the present invention is not limited to this, and one hot water recovery is performed. You may change time according to the implementation frequency of warm water collection | recovery. In this case, for example, a recovery method in which the hot water recovery time at the start of hot water recovery is set short and the hot water recovery time is set longer as the number of hot water recoveries progresses.

<Embodiment 5>
Next, another example of the cooling device of the present invention will be described with reference to FIG.

  In the cooling device of this example, the heat storage relief valve 10 is omitted with respect to the cooling device of <Embodiment 1> described above, and the function of the heat storage relief valve 10 is the valve body 191 of the heat storage thermostat 190 and the compression coil spring 194 (FIG. 17), and the heat storage thermostat 190 is housed in the heat storage tank 8.

  First, a heat storage thermostat 190 used in the cooling device of this example will be described with reference to FIGS.

  The heat storage thermostat 190 of this example includes a valve body 191, a valve seat plate 192, a temperature sensing portion 193, a compression coil spring 194, a rod holding member 195, a spring support plate 196, a cylindrical housing 190h, and the like.

  The housing 190h is provided with a cooling water inlet 190a and a cooling water inlet 190b. Inside the housing 190h, a valve seat plate 192 having a circular through hole in the center and a spring support plate 196 are arranged in a state of facing each other. Further, a rod holding member 195 is disposed on the cooling water inlet 190a side (the side opposite to the valve body 191) of the valve seat plate 192. The valve seat plate 192, the rod holding member 195, and the spring support plate 196 are fixed to the housing 190h. The rod holding member 195 and the spring support plate 196 are processed into a shape that does not hinder the flow of cooling water.

  The valve body 191 is disposed between the valve seat plate 192 and the spring support plate 196 and faces the valve seat plate 192. The valve body 191 and the case 193a of the temperature sensing unit 193 are integrated. Further, a compression coil spring 194 is sandwiched between the valve body 191 and the spring support plate 196, and the valve body 91 is biased toward the valve seat plate 192 by the elastic force of the compression coil spring 194. .

  The temperature sensing unit 193 includes a cylindrical case 193a and a piston rod 193b. The piston rod 193b is slidably disposed on the case 193a. The tip of the piston rod 193b is slidably inserted into the holding hole 195a of the rod holding member 195. The case 193a is filled with a thermowax 193c that expands and contracts due to changes in the cooling water temperature, and the amount of protrusion of the piston rod 193b relative to the case 193a changes due to the expansion and contraction of the thermowax 193c. Yes. The thermowax 193c is accommodated in a sealing material 193d made of rubber or the like.

  And in the heat storage thermostat 190 of the above structure, when the cooling water temperature Thw of the cooling water which contacts the temperature sensing part 193 is more than the setting value A demonstrated in said <Embodiment 1> (A <= Thw), a thermo wax 193c. Expands. Due to the expansion of the thermowax 193c, the protruding amount of the piston rod 193b from the case 193a is increased, and the entire temperature sensing portion 193, that is, the valve body 191, resists the elastic force of the compression coil spring 194 from the valve seat plate 192. The valve body 191 moves away from the valve seat plate 192 and opens (opens) (FIG. 17A). From this state, when the coolant temperature Thw of the coolant that contacts the temperature sensing unit 193 becomes lower than the set value A described in the above <Embodiment 1> (Thw <A), the thermowax 193c contracts, The protruding amount of the piston rod 193b from the case 193a is reduced, and the entire temperature sensing portion 193, that is, the valve body 91 is moved toward the valve seat plate 192 by the elastic force of the compression coil spring 194, and the valve body 91 is seated. The valve is closed (FIG. 17B).

  Thus, the heat storage thermostat 190 in this example is opened when the cooling water temperature Thw of the cooling water contacting the temperature sensing unit 193 is equal to or higher than the set value A, and the cooling water outlet 8b of the heat storage tank 8 shown in FIG. And the cooling water inlet 1a of the engine 1 (suction port 2a of the electric water pump 2) communicate with each other. On the other hand, when the cooling temperature Thw becomes smaller than the set value A, the cooling water passage (cooling water outlet pipe 132) between the cooling water outlet 8b of the heat storage tank 8 and the cooling water inlet 1a of the engine 1 is shut off.

  In the heat storage thermostat 190 of this example, even if the cooling temperature Thw is less than the set value A and the valve is closed, the pump discharge pressure Pw of the electric water pump 2 is the set value described in the above <Embodiment 1>. When β is greater than or equal to (β ≦ Pw), the valve body 191 is pushed away from the valve seat plate 192 against the elastic force of the compression coil spring 194 by the pump discharge pressure Pw, and the valve body 91 is separated (opened). Valve) (FIG. 17C). Thereby, the cooling water outlet 8b of the heat storage tank 8 shown in FIG. 16 and the cooling water inlet 1a of the engine 1 (suction port 2a of the electric water pump 2) communicate with each other.

  The heat storage thermostat 190 having the above structure is accommodated in the heat storage tank 8 (see FIG. 16). The cooling water inlet 190 a of the heat storage thermostat 190 communicates with the lower portion of the inner pipe 81, and the cooling water outlet 8 b of the heat storage tank 8 and the cooling water inlet 190 a of the heat storage thermostat 190 communicate with each other. In addition, the cooling water outlet 190 b of the heat storage thermostat 190 communicates with the cooling water outlet pipe 132.

  Also in this example, the ECU 200 performs the processing of <Embodiment 1> described above based on the output signal of the water temperature sensor 11 and the operation signal (ON / OFF signal) of the ignition switch 12, that is, FIG. Circulating water control is executed by the same processing as in steps ST101 to ST116. The circulating water control (each control at the time of hot water supply, warm-up process, travel traveling, and hot water recovery) will be described with reference to FIGS.

-When supplying hot water-
Since the high temperature water is stored in the heat storage tank 8 when hot water is supplied (the storage of the high temperature water in the heat storage tank 8 will be described later), the temperature of the cooling water contacting the temperature sensing part 193 of the heat storage thermostat 190 is high. The heat storage thermostat 190 is open (FIG. 17A). The cooling water temperature Twh on the engine 1 side obtained from the output signal of the water temperature sensor 11 at the start of hot water supply is equal to or lower than the set value A (Thw <A).

  In this state, the electric water pump 2 is operated at a minute flow rate such that the pump discharge pressure Pw becomes a pressure (Pw <α) smaller than the set value α described in the above <Embodiment 1>. By the operation of the electric water pump 2, as shown in FIG. 18A, the cooling water (low temperature water) from the engine 1 flows into the heat storage tank 8 through the cooling water introduction pipe 131, and accordingly, the heat storage tank The hot water stored in 8 passes through the heat storage thermostat 190 and the cooling water outlet 8 b in the heat storage tank 8, flows out of the tank, and is supplied to the water jacket inside the engine 1 through the cooling water outlet pipe 132.

  Thus, by supplying high temperature water from the heat storage tank 8 to the engine 1 and warming the engine 1, the volatility of the fuel can be increased at an early stage, and the ignitability of the air-fuel mixture can be increased. As a result, engine startability at the time of cold start or the like is improved, and fuel efficiency and exhaust emission can be improved.

  Also in this example, as in <Embodiment 1> described above, the operating time ta of the electric water pump 2 during hot water supply takes into account the response delay of the heat storage thermostat 190, the volume of the heat storage tank 8, and the like. At the timing when the high temperature water in the tank 8 exists in the heat storage thermostat 190 (timing before the low temperature water from the engine 1 reaches the heat storage thermostat 190 in the heat storage tank 8), the closing of the heat storage thermostat 190 is completed. Set the time. By stopping the electric water pump 2 at such timing, it is possible to avoid mixing the high-temperature water supplied to the engine 1 during the supply of hot water and the low-temperature water recovered by the heat storage device 8.

-Warm-up process-
After the above hot water supply is completed, the electric water pump 2 is controlled to have a discharge flow rate corresponding to the operating state of the engine 1. Here, when the hot water supply is completed, the engine thermostat 4 is closed because the cooling water temperature Thw has not reached the warm-up temperature. Since the heat storage thermostat 190 is also closed, as shown in FIG. 18B, [Electric Water Pump 2] → [Engine 1] → [Heater 5] → [EGR Cooler 6] → [Device Relief Valve] 7] → [Engine thermostat 4] → [Electric water pump 2], a cooling water circulation circuit (heater circuit 102) is formed, and in the circulation process, the cooling water is heated by the engine 1 and the cooling water temperature rises.

  During the warm-up by such an engine operation, since the space between the cooling water outlet 8b of the heat storage tank 8 and the cooling water outlet pipe 132 is blocked by the heat storage thermostat 190, the heat storage tank 8 in the hot water supply process described above. The low-temperature water accumulated inside does not flow out to the heater circuit 102. Moreover, the capacity of the cooling water flowing through the heater circuit 102 can be reduced by the amount of the cooling water accumulated in the heat storage tank 8 (including the piping of the heat storage circuit 103). And warm-up can be completed early.

-During normal driving-
During normal travel, as shown in FIG. 19 (a), in addition to the heater circuit 102, [electric water pump 2] → [engine 1] → [radiator 3] → [engine thermostat 4] → [electric water pump 2] The cooling water circuit is formed. That is, the radiator circuit 101 is connected in parallel to the heater circuit 102, a part of the cooling water (high temperature water) circulating through the heater circuit 102 flows into the radiator 3, and the heat of the cooling water is released from the radiator 3 to the outside. During normal running, the discharge flow rate is controlled so that the pump discharge pressure Pw of the electric water pump 2 is within the range [α ≦ Pw <β].

-When recovering hot water-
At the time of hot water recovery, the electric water pump 2 is operated at the maximum flow rate (pump discharge pressure Pw ≧ β). By such an operation of the electric water pump 2, the heat storage thermostat 190 in the heat storage tank 8 is opened (FIG. 17C). As a result, as shown in FIG. 19B, the low-temperature water in the heat storage tank 8 passes through the heat storage thermostat 190 and the cooling water outlet 8b in the heat storage tank 8 and flows out to the outside of the tank. Through the engine 1. Accordingly, the high temperature water on the engine 1 side passes through the cooling water introduction pipe 131 and then flows into the heat storage tank 8, and the high temperature water is recovered in the heat storage tank 8.

  When the cooling water temperature Thw at the time of such hot water recovery is equal to or higher than the operating temperature of the engine thermostat 4 (for example, 82 ° C.), the cooling from the engine 1 is performed as shown by the broken arrow in FIG. Part of the water (hot water) also flows into the radiator 3.

  Also in this example, as in the above-described <Embodiment 1>, at the time of hot water recovery, the cold / hot water exchange between the low temperature water in the heat storage tank 8 and the high temperature water in the engine 1 is not performed at a time, By performing the hot water recovery in N times, the temperature of the cooling water flowing through the engine 1 and the heater circuit 102 is prevented from rapidly decreasing, and the fuel consumption and the heater function are improved.

  Further, after the number of times of hot water recovery becomes N times or more and the current cooling water temperature Thw becomes equal to or higher than the previously stored cooling water temperature during engine operation, the hot water at the hot water recovery time T1 (see FIG. 5). By the recovery (one-time warm water recovery), the high-temperature water on the engine 1 side is recovered in the heat storage tank 8 (see steps ST113 and ST110 to ST112 in FIG. 2). By performing the hot water recovery in such a process, the hot water having the highest cooling water temperature Thw is recovered (stored) in the heat storage tank 8 during the operation of the engine 1 (between IG-ON and IG-OFF). )can do.

  In addition, when IG-OFF (engine stoppage) occurs during hot water recovery, the number n of hot water recovery times (the latest hot water is recovered) during the hot water recovery time [T1 / N] until the IG-OFF. Using the number of times of recovery n), the hot water recovery time Toff described above is obtained based on the number of times of hot water recovery n, and hot water recovery is performed at the temperature of the hot water recovery time Toff (see steps ST114 to ST116 in FIG. 2). By performing such warm water recovery, all the cooling water in the heat storage tank 8 can be replaced with high temperature water even if IG-OFF (engine operation stop) occurs during the warm water recovery.

  If the engine is warmed up during engine operation and becomes IG-OFF (when the number of times hot water is recovered n = 0), the hot water is recovered during the hot water recovery time Toff and the relatively hot water on the engine 1 side is removed. It is recovered (stored) in the heat storage tank 8.

  As described above, also in this example, the hot water supply from the heat storage tank 8 to the engine 1 and the hot water recovery to the heat storage tank 8 of the engine 1 can be performed by the discharge control of one electric water pump 2. Therefore, the hot water supply and hot water recovery functions can be realized with a simple configuration.

  In the above example, when the hot water recovery is performed in N times, one hot water recovery time [T1 / N] is set to a fixed time. However, the present invention is not limited to this, and one hot water recovery is performed. You may change time according to the implementation frequency of warm water collection | recovery. In this case, for example, a recovery method in which the hot water recovery time at the start of hot water recovery is set short and the hot water recovery time is set longer as the number of hot water recoveries progresses.

<Embodiment 6>
Next, another example of the cooling device of the present invention will be described with reference to FIG.

  In the cooling device of this example, the cooling water introduction pipe 131a of the heat storage circuit 103 is connected to the cooling water recirculation pipe 122 on the downstream side of the EGR cooler 6 (downstream side of the cooling water flow) with respect to <Embodiment 5> described above. In other respects, the other configuration is basically the same as the above-described <Embodiment 5>.

  Also in this example, the ECU 200 performs the processing of <Embodiment 1> described above based on the output signal of the water temperature sensor 11 and the operation signal (ON / OFF signal) of the ignition switch 12, that is, FIG. Circulating water control is executed by the same processing as in steps ST101 to ST116. The circulating water control (each control during warm water supply, warm-up process, travel traveling, and hot water recovery) will be described with reference to FIGS.

-When supplying hot water-
Since the high temperature water is stored in the heat storage tank 8 when hot water is supplied (the storage of the high temperature water in the heat storage tank 8 will be described later), the temperature of the cooling water contacting the temperature sensing part 193 of the heat storage thermostat 190 is high. The heat storage thermostat 190 is open (FIG. 17A). The cooling water temperature Twh obtained from the output signal of the water temperature sensor 11 at the start of hot water supply is equal to or lower than the set value A described in <Embodiment 1> (Thw <A).

  In this state, the electric water pump 2 is operated at a minute flow rate such that the pump discharge pressure Pw becomes a pressure (Pw <α) smaller than the set value α described in the above <Embodiment 1>. By the operation of the electric water pump 2, low temperature water from the engine 1 flows into the heat storage tank 8 through the heater 5, the EGR cooler 6 and the cooling water introduction pipe 131a as shown in FIG. Accordingly, the high-temperature water stored in the heat storage tank 8 passes through the heat storage thermostat 190 and the cooling water outlet 8b in the heat storage tank 8 and flows out of the tank, and passes through the cooling water outlet pipe 132 to the inside of the engine 1. Supplied to the water jacket.

  Thus, by supplying high temperature water from the heat storage tank 8 to the engine 1 and warming the engine 1, the volatility of the fuel can be increased at an early stage, and the ignitability of the air-fuel mixture can be increased. As a result, engine startability at the time of cold start or the like is improved, and fuel efficiency and exhaust emission can be improved.

  Also in this example, as in <Embodiment 1> described above, the operating time ta of the electric water pump 2 during hot water supply takes into account the response delay of the heat storage thermostat 190, the volume of the heat storage tank 8, and the like. At the timing when the high temperature water in the tank 8 exists in the heat storage thermostat 190 (timing before the low temperature water from the engine 1 reaches the heat storage thermostat 190 in the heat storage tank 8), the closing of the heat storage thermostat 190 is completed. Set the time. By stopping the electric water pump 2 at such timing, it is possible to avoid mixing the high-temperature water supplied to the engine 1 during the supply of hot water and the low-temperature water recovered by the heat storage device 8.

-Warm-up process-
After the above hot water supply is completed, the electric water pump 2 is controlled to have a discharge flow rate corresponding to the operating state of the engine 1. Here, when the hot water supply is completed, the engine thermostat 4 is closed because the cooling water temperature Thw has not reached the warm-up temperature. Since the heat storage thermostat 190 is also closed, as shown in FIG. 21B, [Electric water pump 2] → [Engine 1] → [Heater 5] → [EGR cooler 6] → [Device relief valve] 7] → [Engine thermostat 4] → [Electric water pump 2], a cooling water circulation circuit (heater circuit 102) is formed, and in the circulation process, the cooling water is heated by the engine 1 and the cooling water temperature rises.

  During the warm-up by such an engine operation, since the space between the cooling water outlet 8b of the heat storage tank 8 and the cooling water outlet pipe 132 is blocked by the heat storage thermostat 190, the heat storage tank 8 in the hot water supply process described above. The low-temperature water accumulated inside does not flow out to the heater circuit 102. Moreover, the capacity of the cooling water flowing through the heater circuit 102 can be reduced by the amount of the cooling water accumulated in the heat storage tank 8 (including the piping of the heat storage circuit 103). And warm-up can be completed early.

-During normal driving-
During normal travel, the discharge flow rate is controlled so that the pump discharge pressure Pw of the electric water pump 2 is within the range of [α ≦ Pw <β]. By such control of the electric water pump 2, as shown in FIG. 22 (a), in addition to the heater circuit 102, [electric water pump 2] → [engine 1] → [radiator 3] → [engine thermostat 4] → A cooling water circuit of [electric water pump 2] is formed. That is, the radiator circuit 101 is connected in parallel to the heater circuit 102, a part of the cooling water (high temperature water) circulating through the heater circuit 102 flows into the radiator 3, and the heat of the cooling water is released from the radiator 3 to the outside.

-When recovering hot water-
At the time of hot water recovery, the electric water pump 2 is operated at the maximum flow rate (pump discharge pressure Pw ≧ β). By such an operation of the electric water pump 2, the heat storage thermostat 190 in the heat storage tank 8 is opened (FIG. 17C). Accordingly, as shown in FIG. 22B, the low-temperature water in the heat storage tank 8 passes through the heat storage thermostat 190 and the cooling water outlet 8b in the heat storage tank 8 and flows out of the tank, and the cooling water outlet pipe 132 is obtained. Through the engine 1. Accordingly, the hot water on the engine 1 side passes through the heater 5 and the EGR cooler 6 and then flows into the heat storage tank 8, and the high temperature water is recovered in the heat storage tank 8.

  When the cooling water temperature Thw at the time of such hot water recovery is equal to or higher than the operating temperature of the engine thermostat 4 (for example, 82 ° C.), the cooling from the engine 1 is performed as shown by the broken arrow in FIG. Part of the water (hot water) also flows into the radiator 3.

  Also in this example, as in the above-described <Embodiment 1>, at the time of hot water recovery, the cold / hot water exchange between the low temperature water in the heat storage tank 8 and the high temperature water in the engine 1 is not performed at a time, By performing the hot water recovery in N times, the temperature of the cooling water flowing through the engine 1 and the heater circuit 102 is prevented from rapidly decreasing, and the fuel consumption and the heater function are improved.

  Further, after the number of times of hot water recovery becomes N times or more and the current cooling water temperature Thw becomes equal to or higher than the previously stored cooling water temperature during engine operation, the hot water at the hot water recovery time T1 (see FIG. 5). By the recovery (one-time warm water recovery), the high-temperature water on the engine 1 side is recovered in the heat storage tank 8 (see steps ST113 and ST110 to ST112 in FIG. 2). By performing the hot water recovery in such a process, the hot water having the highest cooling water temperature Thw is recovered (stored) in the heat storage tank 8 during the operation of the engine 1 (between IG-ON and IG-OFF). )can do.

  In addition, when IG-OFF (engine stoppage) occurs during hot water recovery, the number n of hot water recovery times (the latest hot water is recovered) during the hot water recovery time [T1 / N] until the IG-OFF. Using the number of times of recovery n), the hot water recovery time Toff described above is obtained based on the number of times of hot water recovery n, and hot water recovery is performed at the temperature of the hot water recovery time Toff (see steps ST114 to ST116 in FIG. 2). By performing such warm water recovery, all the cooling water in the heat storage tank 8 can be replaced with high temperature water even if IG-OFF (engine operation stop) occurs during the warm water recovery.

  If the engine is warmed up during engine operation and becomes IG-OFF (when the number of times hot water is recovered n = 0), the hot water is recovered during the hot water recovery time Toff and the relatively hot water on the engine 1 side is removed. It is recovered (stored) in the heat storage tank 8.

  As described above, also in this example, the hot water supply from the heat storage tank 8 to the engine 1 and the hot water recovery to the heat storage tank 8 of the engine 1 can be performed by the discharge control of one electric water pump 2. Therefore, the hot water supply and hot water recovery functions can be realized with a simple configuration.

  In the above example, when the hot water recovery is performed in N times, one hot water recovery time [T1 / N] is set to a fixed time. However, the present invention is not limited to this, and one hot water recovery is performed. You may change time according to the implementation frequency of warm water collection | recovery. In this case, for example, a recovery method in which the hot water recovery time at the start of hot water recovery is set short and the hot water recovery time is set longer as the number of hot water recoveries progresses.

-Other embodiments-
In the above example, the electric water pump is used for circulating the cooling water. However, the present invention is not limited to this, and a mechanical water pump having a variable discharge flow rate (discharge pressure) may be used for the cooling water circulation. .

  In the above example, the device relief valve (first flow valve) is provided on the downstream side (downstream of the cooling water flow) of the heater (heat exchanger), but the device relief valve (first flow valve) is provided on the heater. You may provide in the upstream of.

  In the above example, an example in which the present invention is applied to a cooling device in which a heater and an EGR cooler are incorporated in a cooling water circuit as a heat exchanger has been shown. The present invention can also be applied to a cooling device in which another heat exchanger such as a recovery unit is incorporated.

It is a schematic block diagram which shows an example (Embodiment 1) of the cooling device of this invention. It is a flowchart which shows an example of cooling water circulation control. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of warm water supply (a) and a warming-up process (b) in the cooling device of FIG. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of normal driving | running | working in the cooling device of FIG. It is a figure which shows the number of warm water collection | recovery, warm water collection | recovery time, and warm water collection | recovery time at the time of IG-OFF. It is a schematic block diagram which shows the other example (Embodiment 2) of the cooling device of this invention. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of warm water supply (a) and a warming-up process (b) in the cooling device of FIG. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of normal driving | running | working (a) and a hot water collection | recovery (b) in the cooling device of FIG. It is a schematic block diagram which shows the other example (Embodiment 3) of the cooling device of this invention. It is sectional drawing which shows the structure of the thermal storage thermostat used for the cooling device of FIG. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of warm water supply (a) and a warming-up process (b) in the cooling device of FIG. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of normal driving | running | working (a) and the time of hot water collection | recovery (b) in the cooling device of FIG. It is a schematic block diagram which shows the other example (Embodiment 4) of the cooling device of this invention. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of warm water supply (a) and a warming-up process (b) in the cooling device of FIG. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of normal driving | running | working (a) and a hot water collection | recovery (b) in the cooling device of FIG. It is a schematic block diagram which shows the other example (Embodiment 5) of the cooling device of this invention. It is sectional drawing which shows the structure of the thermal storage thermostat used for the cooling device of FIG. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of warm water supply (a) and a warming-up process (b) in the cooling device of FIG. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of normal driving | running | working (a) and a hot water collection | recovery (b) in the cooling device of FIG. It is a schematic block diagram which shows the other example (Embodiment 6) of the cooling device of this invention. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of warm water supply (a) and a warming-up process (b) in the cooling device of FIG. It is a figure which shows the flow of the cooling water which circulates through a cooling water circuit at the time of normal driving | running | working (a) and warm water collection | recovery (b) in the cooling device of FIG.

Explanation of symbols

1 Engine 1b Coolant outlet 2 Electric water pump 3 Radiator 4 Engine thermostat 5 Heater core 6 EGR cooler 7 Device relief valve (first valve)
8 Thermal storage tank 9 Thermal storage thermostat (second valve)
90,190 Thermal storage thermostat (second and third valves)
94 First compression coil spring 194 Compression coil spring 10 Thermal storage relief valve (third valve)
100 Cooling Water Circuit 101 Radiator Circuit 102 Heater Circuit (First Cooling Water Circuit)
103 Heat storage circuit (second cooling water circuit)
200 ECU

Claims (10)

A cooling device incorporating a heat storage device for storing a part of cooling water heated by an internal combustion engine in a heat-retaining state, wherein the cooling water is circulated through the internal combustion engine and the heat exchanger. A cooling device for an internal combustion engine comprising a circuit, a second cooling water circuit for circulating cooling water via the internal combustion engine and the heat storage device, and a water pump,
The cooling water outlet of the heat exchanger and the cooling water outlet of the heat storage device communicate with the cooling water inlet of the internal combustion engine, and for cooling water circulation between the first cooling water circuit and the second cooling water circuit, A water pump with variable pump discharge pressure is used in combination without depending on the rotational speed of the internal combustion engine,
Provided on the cooling water inlet side or the cooling water outlet side of the heat exchanger, the valve is closed when the pump discharge pressure of the water pump is smaller than a first set value, and the pump discharge pressure is not less than the first set value. A first valve that opens at a certain time and a cooling water outlet side of the heat storage device are open when the cooling water temperature is lower than a set value, and the cooling water temperature is equal to or higher than the set value. A second valve on the outlet side that has a response delay from the point of time until the valve is closed ;
At the time of heat dissipation of the heat storage device, the outlet-side second valve is open, and when the outlet-side second valve is open, the pump discharge pressure is such that the first valve is closed. A cooling device for an internal combustion engine, which operates the water pump to supply high-temperature cooling water stored in the heat storage device to the internal combustion engine. The cooling apparatus for an internal combustion engine according to claim 1,
In consideration of the responsiveness of the valve closing with respect to the cooling water temperature of the outlet-side second valve, the water pump is stopped at a timing at which the low-temperature water recovered from the internal combustion engine to the heat storage device does not flow into the internal combustion engine. An internal combustion engine cooling device. The cooling apparatus for an internal combustion engine according to claim 1 or 2 ,
A cooling apparatus for an internal combustion engine , wherein the water pump is operated at a pump discharge pressure such that the first valve is opened after heat release from the heat storage device. A cooling device incorporating a heat storage device for storing a part of cooling water heated by an internal combustion engine in a heat-retaining state, wherein the cooling water is circulated through the internal combustion engine and the heat exchanger. A cooling device for an internal combustion engine comprising a circuit, a second cooling water circuit for circulating cooling water via the internal combustion engine and the heat storage device, and a water pump,
The cooling water outlet of the heat exchanger and the cooling water outlet of the heat storage device communicate with the cooling water inlet of the internal combustion engine, and for cooling water circulation between the first cooling water circuit and the second cooling water circuit, A water pump with variable pump discharge pressure is used in combination without depending on the rotational speed of the internal combustion engine,
Provided on the cooling water inlet side or the cooling water outlet side of the heat exchanger, the valve is closed when the pump discharge pressure of the water pump is smaller than a first set value, and the pump discharge pressure is not less than the first set value. A first valve that opens at a certain time, and an internal second valve that is provided inside the heat storage device and that opens when the coolant temperature is equal to or higher than a set value,
The internal second valve is in an open state when the heat storage device dissipates heat, and when the internal second valve is in an open state, the water pressure is such that the first valve is closed. A cooling device for an internal combustion engine, wherein a high-temperature cooling water stored in the heat storage device is supplied to the internal combustion engine by operating a pump . The cooling apparatus for an internal combustion engine according to claim 4 ,
A cooling apparatus for an internal combustion engine , wherein the water pump is operated at a pump discharge pressure such that the first valve is opened after heat release from the heat storage device. The cooling apparatus for an internal combustion engine according to any one of claims 1 to 5,
A third valve that closes when a pump discharge pressure of the water pump is smaller than a second set value that is larger than the first set value, and opens when a pump discharge pressure is equal to or greater than the second set value. In parallel with the outlet-side second valve or the internal second valve, and the third valve is opened during the operation of the internal combustion engine when recovering heat to the heat storage device. A cooling apparatus for an internal combustion engine, wherein a part of cooling water heated by the internal combustion engine is recovered in the heat storage device by operating the water pump with a discharge pressure . The cooling device for an internal combustion engine according to claim 6 ,
The outlet-side second valve or the internal second valve is a thermostat having a compression coil spring that presses the valve body toward the closing side, and a relief valve is configured using the valve body and the compression coil spring. the cooling system of an internal combustion engine to which the outlet-side second valve or inside the second valve, characterized in that have a function of said third valve. The cooling apparatus for an internal combustion engine according to claim 6 or 7 ,
Water temperature storage means for storing the temperature of the cooling water at the time of heat recovery to the heat storage device is provided, and the cooling water temperature stored in the water temperature storage means is compared with the current cooling water temperature during the operation of the internal combustion engine. The cooling system for an internal combustion engine , wherein the heat recovery is executed when the current coolant temperature is equal to or higher than the coolant temperature stored in the previous time . The cooling apparatus for an internal combustion engine according to any one of claims 6 to 8 ,
A cooling apparatus for an internal combustion engine, wherein heat recovery to the heat storage device is executed in a plurality of times . The cooling apparatus for an internal combustion engine according to claim 9 ,
A cooling apparatus for an internal combustion engine, wherein the heat recovery time is variable according to the number of times of heat recovery to the heat storage device.

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