JP2008082225A - Cooling device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device for an engine capable of surely supplying high temperature cooling water to a heat storage tank after engine stop and supplying high temperature cooling water from the heat storage tank to the engine at a time of cold start thereafter. <P>SOLUTION: The cooling device 10 for the engine is provided with a main circuit 1 circulating liquid heat medium between a radiator 12 and the engine 13, the heat storage tank 19 storing heat of heat medium in the main circuit 1, a circuit 3 for the heat storage tank supplying heat medium from the heat storage tank to the engine side, and an oil cooler 18. The device is provided with an after-halt circuit 4 having a pump 21 forcibly supplying heat medium to the heat storage tank 19 from the oil cooler 18 after engine stop installed therein. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an engine cooling apparatus.

  In general, in an engine cooling device, cooling water (liquid heat medium) is passed through a water jacket of the engine to exchange heat between the cooling water and the engine, thereby suppressing an increase in engine temperature.

  Here, in order to improve the cold startability of the engine, it is known to use the heat of the cooling water whose temperature has been raised by heat exchange with the engine described above.

For example, Patent Document 1 discloses the use of a heat storage tank that stores heat of cooling water that has passed through an engine in order to improve the cold startability. This heat storage tank is provided on a circuit capable of circulating the cooling water between the engine and the engine by the arrangement of the electric pump. That is, by starting the electric pump after stopping the engine, the cooling water heated by the heat exchange with the engine is supplied to the heat storage tank to store the heat, and then the electric pump is started again at the cold start, thereby storing the heat. Cooling water stored in the tank is supplied to the engine to warm up the engine and improve engine startability.
JP 2002-309936 A

  However, for example, when the outside air temperature is low, the cooling water supplied from the engine to the heat storage tank does not become a high temperature even by heat exchange with the engine, so that it may not be possible to store heat sufficiently in the heat storage tank. In this case, high-temperature cooling water cannot be supplied to the engine side at the time of subsequent engine start, for example, at the time of cold start.

  The present invention has been made in view of the above points, and the object of the present invention is to reliably supply high-temperature cooling water to the heat storage tank after the engine is stopped, and from the heat storage tank at the subsequent cold start. An object of the present invention is to provide an engine cooling device capable of supplying high-temperature cooling water to the engine side.

  In the present invention, a heat medium is forcibly supplied from an oil cooler to a heat storage tank after the engine is stopped.

  Specifically, in the invention of claim 1, there is provided a main circuit for circulating a liquid heat medium between a radiator and an engine, and a heat storage tank connected to the main circuit and storing heat of the heat medium of the main circuit. An engine cooling device that is disposed and includes a heat storage tank circuit that supplies a heat medium from the heat storage tank to the engine side, and that includes an oil cooler.

  Thus, a post-stop circuit is provided that opens from the closed state during engine operation when the engine is stopped and forcibly supplies the heat medium from the oil cooler to the heat storage tank by a pump that operates when the engine is stopped.

  According to the present invention, after the engine is stopped, the heat medium is supplied from the oil cooler to the heat storage tank. However, the cooling water passage portion in the oil cooler exchanges heat with oil having a temperature higher than that of the cooling water, so The temperature is raised compared to the jacket. Therefore, the cooling water that passes through the oil cooler becomes higher in temperature than the cooling water that has passed through the engine due to heat exchange with the cooling water passage portion.

  Thus, the coolant that has passed through the oil cooler and has become high temperature is supplied to the heat storage tank via the post-stop circuit by the pump after the engine is stopped. As a result, the heat storage tank is sufficiently stored, and cooling water maintained at a high temperature in the heat storage tank can be supplied to the engine side at the time of a cold start later.

  In the invention of claim 2, further comprising a heater circuit that is connected to the main circuit so as to bypass the radiator, and that is provided with a heater for air conditioning in the vehicle interior, the downstream portion of the heat storage tank circuit is: The heater circuit is connected upstream of the heater.

  That is, the fact that the downstream portion of the heat storage tank circuit is connected to the upstream side of the heater in the heater circuit means that high-temperature cooling water is supplied from the heat storage tank to the heater as the engine starts. is there. Thereby, even at the time of a cold start, the temperature of a heater can be raised rapidly and the immediate effect of heating is acquired.

  According to a third aspect of the present invention, the oil cooler is disposed on the downstream side of the heater in the heater circuit, and the upstream portion of the post-stop circuit is connected to the downstream side of the oil cooler of the heater circuit.

  Thereby, the effect of the invention of claim 1 can be obtained with certainty.

  According to a fourth aspect of the present invention, the upstream portion of the heat storage tank circuit is connected to a path from the radiator of the main circuit to the engine, and the intake air of the engine is disposed downstream of the heat storage tank of the heat storage tank circuit. An intake air cooler for cooling the engine is disposed.

  That is, the intake air cooler of the engine is disposed downstream of the heat storage tank of the heat storage tank circuit. This means that the cooling water flowing out of the radiator when the engine starts is passed through the heat storage tank. It is to be supplied to. Therefore, it is possible to cool the intake air cooler by supplying the cooling water that has passed through the radiator and becomes low temperature to the intake air cooler during the warm period. As a result, the intake air temperature can be stabilized at a low level during the warm period, and the intake air charging efficiency of the engine can be increased.

  According to the first aspect of the present invention, after the engine is stopped, the heat medium is supplied from the oil cooler to the heat storage tank, but the cooling water passage portion in the oil cooler is heated with oil having a temperature higher than that of the cooling water. As a result of the replacement, the temperature is increased compared to the water jacket of the engine. Then, the cooling water that has become high temperature through the oil cooler in this way is supplied to the heat storage tank through the circuit after the stop by the pump after the engine is stopped, so that the heat storage tank is sufficiently stored, At the time of cold starting later, the cooling water maintained at a high temperature in the heat storage tank can be supplied to the engine side.

  According to the second aspect of the present invention, since the downstream portion of the heat storage tank circuit is connected to the upstream side of the heater in the heater circuit, high-temperature cooling water is supplied from the heat storage tank as the engine starts. , Supplied to the heater. Thereby, even at the time of a cold start, the temperature of a heater can be raised rapidly and the immediate effect of heating is acquired.

  According to the third aspect of the present invention, the oil cooler is disposed on the downstream side of the heater in the heater circuit, and the upstream portion of the post-stop circuit is connected to the downstream side of the oil cooler of the heater circuit. Is done. Thereby, the effect of the invention of claim 1 can be obtained with certainty.

  According to the fourth aspect of the present invention, since the intake air cooler of the engine is disposed downstream of the heat storage tank of the circuit for the heat storage tank, the cooling water flowing out from the radiator with the start of the engine is reduced. , Can be supplied to the intake air cooler. Therefore, it is possible to cool the intake air by supplying the cooling water having passed through the radiator and having a low temperature to the intake air cooler when it is warm. As a result, the intake air temperature can be stabilized at a low level and the engine output can be increased when warm.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a configuration of an engine cooling apparatus 10 according to the first embodiment.

  Reference numeral 1 denotes a main circuit for circulating cooling water between a radiator (R / D in the figure) 12 and an engine 13, and a thermostat (T / S in the figure) is connected to a cooling water supply path 1a from the radiator 12 to the engine 13. ) 14 and a water pump (WP in the figure) 15 are arranged in series so as to be arranged in order from the upstream side.

  Further, in the main circuit 1, a bypass passage 1c branches from a return path 1b from the engine 13 toward the radiator 12, bypasses the radiator 12, and has a downstream end connected to the upstream side of the water pump 15 of the cooling water supply path 1a. Is provided. A throttle 16 is provided in the bypass passage 1c.

  Further, the main circuit 1 includes a heater circuit 2 in which a heater 17 and an oil cooler 18 for air conditioning in a vehicle compartment are arranged in order from the upstream side, a heat storage tank 19 for storing heat of cooling water of the main circuit 1, and A heat storage tank circuit 3 is connected in series so that the intake air coolers 20 for cooling the intake air of the engine are arranged in order from the upstream side.

  The heater circuit 2 branches from the return path 1 b of the main circuit 1, bypasses the radiator 12, and has a downstream end connected to the upstream side of the water pump 15 in the main circuit 1.

  The heat storage tank circuit 3 branches from the upstream side of the thermostat 14 in the cooling water supply path 1 a of the main circuit 1, and the downstream end is connected to the upstream side of the heater 17 in the heater circuit 2.

  The heater circuit 2 and the heat storage tank circuit 3 are connected by a post-stop circuit 4 in which an electric pump (pump) 21 is disposed.

  That is, the post-stop circuit 4 branches from the downstream side of the oil cooler 18 in the heater circuit 2, the downstream end is connected to the upstream side of the heat storage tank in the heat storage tank circuit 3, and the electric pump 21 is connected to the engine 13. Is provided so that the cooling water can be forcibly supplied directly from the oil cooler 18 to the heat storage pump.

 Further, the heat storage tank circuit 3 and the post-stop circuit 4 are provided with a first on-off valve 3a and a second on-off valve 4a for opening and closing each water channel upstream of the connection portion between the circuits 3 and 4. Has been.

 The cooling device 10 is also provided with an electronic control unit 22 (hereinafter, ECU 22) that controls the opening and closing of the first and second on-off valves 3a and 4a and the driving of the electric pump 21. The ECU 22 is connected to a water temperature sensor 23 that measures the temperature of the cooling water in the engine 13, and opens and closes the first and second on-off valves 3 a and 4 a based on a signal received from the water temperature sensor 23 and on / off of the engine 13. The driving of the electric pump 21 is controlled.

  That is, when the engine coolant temperature is warmer than a first set value (for example, 90 ° C.), the first on-off valve 3a is open, the second on-off valve 4a is closed, and the temperature is less than the first set value. The first on-off valve 3a is controlled to open and the second on-off valve 4a is controlled to open.

  Further, when the engine is stopped, the first on-off valve 3a is controlled to be closed and the second on-off valve 4a is controlled to open.

  The electric pump 21 is driven for a predetermined time after the engine is stopped.

  FIG. 2 shows the flow of cooling water in the cooling device 10 after the engine is stopped in the first embodiment.

  As the engine stops, the ECU 22 closes the first on-off valve 3a, opens the second on-off valve 4a, and drives the electric pump 21 for a predetermined time from when the engine is stopped. When the engine is stopped, the water pump 15 is stopped and the thermostat 14 is also closed because high-temperature cooling water is not supplied.

  By driving the electric pump 21, the cooling water flows from the oil cooler 18 to the circuit 4 after the stop, and the flowing cooling water flows to the heat storage tank 19.

  The temperature of the coolant passage in the oil cooler 18 is higher than that of the water jacket of the engine 13 due to heat exchange with high-temperature oil. Therefore, the cooling water that has passed through the oil cooler 18 becomes higher in temperature than the cooling water that has passed through the water jacket of the engine 13 due to heat exchange with the cooling water passage portion. Then, the cooling water that has become a high temperature by utilizing the heat of the oil is supplied to the heat storage tank 19 after the engine 13 is stopped, whereby the high-temperature cooling water is stored in the heat storage tank 19. The amount of stored heat increases.

  Further, since the upstream part of the post-stop circuit 4 is connected to the downstream part of the oil cooler 18 of the heater circuit 2, the coolant that has become hot due to the use of oil heat is After the stop, only the circuit 4 is passed and supplied to the heat storage tank 19. Thereby, the high-temperature cooling water is supplied to the heat storage tank 19 without being cooled by passing through another circuit.

  FIG. 3 is a schematic diagram illustrating the flow of cooling water in the cooling device 10 during the cold start according to the first embodiment.

  First, high-temperature cooling water is stored in the heat storage tank 19 when the engine 13 has been previously stopped as described above.

  Thus, at the time of cold start (when the temperature of the cooling water in the engine 13 is 15 degrees or less, for example, when the engine 13 is started), the ECU 22 performs the first operation based on the signal received from the water temperature sensor 23. The on-off valve 3a is closed and the second on-off valve 4a is opened. Note that the ECU 22 stops the electric pump 21 during the cold start. Further, the thermostat 14 closes the cooling water supply path 1a, and the circulation of the cooling water between the radiator 12 and the engine 13 is stopped. In addition, the water pump 15 is driven by starting the engine 13.

  By driving the water pump 15, in the main circuit 1, the coolant passes through the engine 13, passes through the bypass passage 1 c so as to bypass the radiator 12 from the return passage 1 b, and flows to the water pump 15.

  Further, a part of the cooling water flowing out from the engine 13 and passing through the return path 1 b of the main circuit 1 flows into the heater circuit 2, and the flowing cooling water passes through the heater 17 and the oil cooler 18. Flow to the water pump 15.

  Further, part of the cooling water that has passed through the oil cooler 18 of the heater circuit 2 flows into the circuit 4 after the stop, and the flowing cooling water flows into the heat storage tank circuit 3.

  Therefore, in the heat storage tank circuit 3, first, the cooling water stored in a high temperature state in the heat storage tank 19 due to the previous engine stop flows to the intake cooler 20 and further to the heater 17.

  As described above, since the high-temperature cooling water flows from the heat storage tank 19 to the intake air cooler 20, the intake air is heated, so that the combustion property of the engine is improved and the cold startability is improved.

  Further, as described above, at the time of cold start, high-temperature cooling water further flows from the heat storage tank to the heater 17. Thereby, heater temperature rises rapidly and the immediate effect of heating is acquired.

  FIG. 4 is a schematic diagram showing the flow of cooling water in the cooling device 10 during the warm time of the first embodiment.

  When warm (when the water temperature in the engine 13 is 90 degrees or more, for example), the ECU 22 opens the first on-off valve 3a and closes the second on-off valve 4a based on the signal received from the water temperature sensor 23. To do. Even during the warm period, the ECU 22 stops the electric pump 21 as in the cold start. In addition, the thermostat 14 opens the cooling water supply path 1 a so as to circulate cooling water between the radiator 12 and the engine 13.

  As a result, in the main circuit 1, the cooling water flowing out from the engine 13 passes through the return path 1b and flows to the radiator 12, and further the cooling water flowing out from the radiator 12 passes through the cooling water supply path 1a, It flows to the water pump 15.

  Further, a part of the cooling water flowing out from the engine 13 and passing through the return path 1 b of the main circuit 1 flows into the heater circuit 2, and the flowing cooling water passes through the heater 17 and the oil cooler 18. Flow to the water pump 15.

  Further, a part of the cooling water flowing out of the radiator 12 and passing through the cooling water supply path 1 a of the main circuit 1 flows into the heat storage tank circuit 3, and the flowing cooling water passes through the heat storage tank 19. Then, it flows to the intake air cooler 20 and further to the heater 17.

  As described above, the cooling water flowing out from the radiator 12 is supplied to the intake air cooler 20 when it is warm. Therefore, the cooling water that has passed through the radiator 12 and has a low temperature is supplied to the intake air cooler 20 during the warm period. As a result, the intake air temperature is stabilized at a low level during warm periods, and the intake charging efficiency is increased.

  As is apparent from the above, the cooling device 10 of the present embodiment supplies high-temperature cooling water to the intake air cooler 20 and the heater 17 at the time of cold start, and supplies low-temperature cooling water to the intake air cooler 20 during the warm time. It is possible to do that. Thereby, the cooling device 10 of the present embodiment can exhibit a plurality of effects of improving the startability of the engine 13 at the time of cold start and the immediate effect of heating in the vehicle, and improving the engine output at the time of warm. is there.

  FIG. 5 is a schematic diagram showing the configuration of the engine cooling device 11 according to the second embodiment.

  The cooling device 11 in the second embodiment is different from the cooling device 10 in the first embodiment in the configuration of the heat storage tank circuit, and other configurations are the same as those in the first embodiment. It is the same as that shown. Therefore, the following description will focus on the differences from the first embodiment, and the points common to the first embodiment will be denoted by the same reference numerals as in the first embodiment in FIG. Description is omitted.

  In the second embodiment, the heat storage tank circuit 3A is not provided with the intake air cooler 20 shown in FIGS. 1 to 4 in the first embodiment, and the downstream end of the heat storage tank circuit 3A is a cylinder of the engine 13. Connected directly to the head water jacket.

  FIG. 6 is a schematic diagram showing the flow of cooling water in the cooling device 11 during cold start in the second embodiment.

  First, at the beginning of the cold start, similarly to the first embodiment, high-temperature cooling water from the oil cooler 18 is stored in the heat storage tank 19 due to the previous engine stop. Note that the process of storing high-temperature cooling water in the heat storage tank 19 is the same as in the first embodiment.

  Then, the ECU 22 closes the first on-off valve 3a and opens the second on-off valve 4a based on the signal received from the water temperature sensor 23. Note that the ECU 22 stops the electric pump 21 as in the cold start of the first embodiment. Further, the thermostat 14 closes the cooling water supply path 1a so as to stop the circulation of the cooling water between the radiator 12 and the engine 13. Further, the water pump 15 starts to be driven by the start of the engine 13.

 As a result, the flow of the cooling water in the main circuit 1, the heater circuit 2, and the post-stop circuit 4 accompanying the driving of the water pump 15 is the same as that shown in FIG.

  On the other hand, in the heat storage tank circuit 3 </ b> A, high-temperature cooling water stored in the heat storage tank flows directly into the water jacket of the cylinder head of the engine 13. As a result, at the time of cold start, high-temperature cooling water is directly supplied into the engine 13, so that the temperature of the cylinder head of the engine rises, the engine combustion stability is improved, and the engine startability is improved. .

It is the schematic diagram which showed the structure of the cooling device of the engine in 1st Embodiment. In 1st Embodiment, it is the schematic diagram which showed the flow of the cooling water in the cooling device after an engine stop. It is the schematic diagram which showed the flow of the cooling water in the cooling device at the time of the cold start of 1st Embodiment. It is the schematic diagram which showed the flow of the cooling water in the cooling device at the time of warm of 1st Embodiment. It is the schematic diagram which showed the structure of the cooling device of the engine in 2nd Embodiment. In 2nd Embodiment, it is the schematic diagram which showed the flow of the cooling water in the cooling device at the time of a cold start.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main circuit 2 Heater circuit 3, 3A Thermal storage tank circuit 4 Stopped circuit 10, 11 Cooling device 12 Radiator 13 Engine 17 Heater 18 Oil cooler 19 Thermal storage tank 20 Intake cooler 21 Pump

Claims (4)

A main circuit for circulating a liquid heat medium between the radiator and the engine;
A heat storage tank connected to the main circuit, storing a heat storage tank that stores heat of the heat medium of the main circuit, and supplying the heat medium from the heat storage tank to the engine; and
An engine cooling device comprising an oil cooler to which the heat medium is supplied,
An engine comprising a post-stop circuit that is opened when the engine is stopped from a closed state during engine operation, and forcibly supplies a heat medium from the oil cooler to the heat storage tank by a pump that operates when the engine is stopped. Cooling system. The heater circuit is further connected to the main circuit so as to bypass the radiator, and is provided with a heater for air conditioning in the vehicle interior,
The engine cooling device according to claim 1, wherein a downstream portion of the heat storage tank circuit is connected to an upstream side of a heater in the heater circuit. The oil cooler is disposed on the downstream side of the heater in the heater circuit,
The engine cooling device according to claim 2, wherein an upstream portion of the post-stop circuit is connected to a downstream side of an oil cooler of the heater circuit. The upstream part of the heat storage tank circuit is connected to a path from the radiator of the main circuit to the engine,
The engine cooling according to any one of claims 1 to 3, wherein an intake air cooler that cools intake air of the engine is disposed downstream of the heat storage tank of the heat storage tank circuit. apparatus.

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