JP2013113118A - Engine cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable promotion of temperature rising of a supercharger 2 only when the warming-up of the supercharger 2 is needed, in an engine cooling device provided with: a high-temperature coolant circulation path 20 for extracting coolant for an engine 1 with the supercharger 2 to the outside followed by returning; and a low-temperature coolant circulation path 30 for circulating coolant to be supplied to a water-cooled intercooler 3.SOLUTION: The engine cooling device includes flow path control means (41, 42) for forming a first flow path (refer to the solid line arrow) for circulating the coolant extracted from the engine 1 to a water jacket 2b provided on the supercharger 2 or a second flow path for circulating the coolant in the low-temperature coolant circulation path 30 to the water jacket 2b (refer to the dashed line arrow in Fig.2). A control unit 100 controls the flow path control means (41, 42) to form the first flow path (refer to the solid line arrow) when coolant temperature thw2 in the low-temperature coolant circulation path 30 is a predetermined threshold Y or less.

Description

  The present invention supplies a high-temperature coolant circulation path for taking out and returning the coolant of an engine with a supercharger to the outside, and a water-cooled intercooler for cooling compressed intake air from the compressor of the supercharger The present invention relates to an engine cooling device including a low-temperature coolant circulation path through which coolant to be circulated.

  For example, Patent Document 1 discloses a cooling water circuit in which a coolant circulates between a water jacket and a radiator of an engine with a turbocharger, and an intercooler and a radiator for cooling compressed intake air from a compressor of the turbocharger. The coolant is circulated between the water jacket of the engine and the radiator during engine operation, with a coolant circuit in which the coolant circulates and a switching valve provided on the inlet side and the outlet side of the water jacket of the turbocharger. Is distributed to the water jacket of the turbocharger, and the cooling water of the intercooler is distributed to the water jacket of the turbocharger for a predetermined time after the engine is stopped.

  In this patent document 1, the turbocharger is cooled while the engine is operating to maintain the cooling capacity of the intercooler, and after the engine is stopped, the residual heat of the turbocharger is removed and the bearing for supporting the turbine shaft is seized. The aim is to prevent.

Japanese Utility Model Publication No. 4-21724

  In the case of the above-mentioned Patent Document 1, a part of the coolant circulating between the water jacket of the engine and the radiator is circulated to the water jacket of the turbocharger regardless of the coolant temperature of the water jacket of the turbocharger during engine operation. I am doing so. Therefore, for example, although it is possible to promote the temperature increase of the turbocharger, there is a concern that the turbocharger will be excessively heated after the engine is warmed up.

  In view of such circumstances, the present invention provides a high-temperature coolant circulation path for taking out the coolant of an engine with a supercharger and returning it to the outside, and cooling compressed intake air from the compressor of the supercharger. In an engine cooling device having a low-temperature coolant circulation path through which coolant supplied to a water-cooled intercooler is circulated, the temperature rise of the turbocharger can be promoted only when the turbocharger needs to be warmed up The purpose is to do.

  An engine cooling device according to the present invention includes a high-temperature coolant circulation path for taking out and returning a coolant of an engine with a supercharger to the outside, and a water-cooling type for cooling compressed intake air from a compressor of the supercharger A low-temperature coolant circulation path through which the coolant supplied to the intercooler is circulated, and the low-temperature coolant through the water jacket provided in the supercharger and the first flow path through which the coolant taken out from the engine flows. A flow path control means for creating a second flow path for circulating the coolant in the coolant circulation path, and a control section for controlling the operation of the flow path control means, wherein the control section is configured to circulate the low-temperature coolant. The flow path control means is controlled so as to create the first flow path when the coolant temperature of the path is equal to or lower than a predetermined threshold value.

  In the first place, when the engine is cold started, the temperature of the coolant in the high-temperature coolant circulation path rises relatively quickly with the heat of the combustion chamber of the engine, and when the engine is warmed up, Circulation keeps the coolant temperature at the warm-up completion temperature. On the other hand, since the low-temperature coolant circulation path is provided for the purpose of cooling the compressed intake air from the compressor of the supercharger with a water-cooled intercooler, the coolant temperature in the low-temperature coolant circulation path is relatively low. Need to be low temperature. For this reason, the coolant circulation path for cooling the engine is referred to as a “high temperature coolant circulation path”, and the coolant circulation path for cooling the intercooler is referred to as a “low temperature coolant circulation path”.

  Here, for example, when the engine is started in a situation where the outside air temperature is low, since the lubricating oil viscosity of the bearing portion for supporting the turbine shaft of the turbocharger is high and the lubricity is insufficient, the friction of the turbocharger is reduced. There is a concern that the oil film damping of the bearing portion becomes worse as it becomes larger.

  Therefore, in the present invention, for example, when the engine is started in a situation where the outside air is at a low temperature, that is, in a situation where the coolant temperature in the low-temperature coolant circulation path is equal to or lower than a predetermined threshold, the controller and the flow path control means By forming the first flow path, the coolant taken out from the engine is circulated through a water jacket provided in the supercharger.

  As a result, the turbocharger is warmed by the engine coolant that rises relatively quickly, so that the viscosity of the lubricating oil decreases relatively quickly and the lubricity increases. As a result, it is possible to stabilize the operation of the supercharger such that the friction of the bearing portion is reduced and the oil film damping of the bearing portion is improved. In addition, since the supercharger is warmed by the engine coolant only when the coolant temperature in the low-temperature coolant circulation path is equal to or lower than a predetermined threshold, the supercharger is excessively heated at other times. You do n’t have to.

  Preferably, the control unit controls the flow path control means so as to create the second flow path when the coolant temperature of the low-temperature coolant circulation path exceeds the predetermined threshold. can do.

  Here, in the state in which the first flow path is secured, the coolant temperature of the low-temperature coolant circulation path increases as the coolant temperature of the high-temperature coolant circulation path increases. When the coolant temperature in the low-temperature coolant circulation path exceeds the predetermined threshold value, it is not necessary to warm up the supercharger. Therefore, the second flow path is created by the control unit and the flow path control means. ing.

  As a result, the coolant in the low-temperature coolant circulation path flows through the water jacket provided in the supercharger, so that the supercharger is gradually cooled.

  Preferably, the high-temperature coolant circulation path is provided with a water pump for circulating the coolant, and a radiator for exchanging heat with the outside air from the water jacket of the engine. The liquid circulation path includes an electric water pump for circulating the coolant, a radiator for exchanging heat between the circulating coolant and the outside air, a bypass for the radiator, and a water jacket for the supercharger on the way. A radiator bypass path connected in series; an upstream communication path connected to communicate an outlet of the water jacket of the engine and an inlet side portion of the water jacket of the supercharger in the radiator bypass path; The outlet side portion of the water jacket of the supercharger in the radiator bypass path and the A downstream side communication passage connected them to communicate with the cooling liquid inlet side to the radiator in the hot cooling fluid circulation passage is provided, it can be configured.

  Here, the configurations of the high-temperature coolant circulation path and the low-temperature coolant circulation path are specified. Thereby, the form which implements this invention becomes clear.

  Preferably, the flow path control unit is installed at an upstream three-way valve installed at a connection portion of the upstream communication passage with respect to the radiator bypass passage and at a connection portion of the downstream communication passage with respect to the radiator bypass passage. A downstream three-way valve, and the upstream three-way valve directs the coolant of the engine water jacket to the water jacket of the supercharger through the upstream communication path and the radiator bypass path. And a second state in which the coolant in the low-temperature coolant circulation path is switched from the radiator bypass path to the water jacket of the turbocharger, and the downstream three-way valve is connected to the turbocharger. A first state in which the coolant is led from the outlet side of the water jacket to the radiator of the high-temperature coolant circulation path through the downstream-side flow passage, and the supercharger It is configured to be switched to a second state in which the coolant is led from the outlet side of the water jacket to the low-temperature coolant circulation path, and when the control unit creates the first flow path, the upstream three-way valve and the Both the downstream three-way valve is controlled to be in the first state, and when the second flow path is formed, the upstream three-way valve and the downstream three-way valve are both controlled to be in the second state. It can be configured.

  Here, the configuration of the flow path control means is specified. Thereby, the form which implements this invention becomes clear.

  The present invention supplies a high-temperature coolant circulation path for taking out and returning the coolant of an engine with a supercharger to the outside, and a water-cooled intercooler for cooling compressed intake air from the compressor of the supercharger In the engine cooling device including the low-temperature coolant circulation path through which the coolant to be circulated, the temperature rise of the turbocharger can be promoted only when the turbocharger needs to be warmed up. In addition, the engine cooling device according to the present invention can prevent an excessive temperature rise of the supercharger after the warm-up of the supercharger is completed.

It is a figure which shows schematic structure of one Embodiment of the engine cooling apparatus which concerns on this invention, and has shown the flow of the cooling fluid when both three-way valves are in a 1st state. It is a figure which shows schematic structure of one Embodiment of the engine cooling apparatus which concerns on this invention, and has shown the flow of the cooling fluid when both three-way valves are in a 2nd state. It is a flowchart used for operation | movement description by ECU of FIG. 1 and FIG.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.

  1 to 3 show an embodiment of the present invention. A supercharger 2 is attached to the engine 1 of this embodiment.

  Although not shown in detail in the supercharger 2, the turbine is rotated by exhaust gas flowing from the exhaust passage of the engine 1 into the turbine housing, and from the intake passage of the engine 1 by a compressor that rotates integrally with the turbine. The intake air taken into the compressor housing is compressed (supercharged), and this compressed air is taken into the engine 1.

  Since the compressed intake air supplied to the engine 1 increases in density and temperature, a water-cooled intercooler 3 is provided to cool the compressed intake air. The water-cooled intercooler 3 includes a heat exchanger for exchanging heat between the compressed intake air from the compressor and the coolant.

  A bearing portion (not shown) for rotatably supporting the turbine shaft (not shown) of the supercharger 2 lubricates and cools the floating bush (not shown) with lubricating oil. Since the bearing portion becomes hot, a water jacket 2b is provided on the bearing housing 2a of the supercharger 2 in order to further cool the bearing portion.

  The engine 1 is provided with a high-temperature coolant circulation path 20 and a low-temperature coolant circulation path 30. The coolant filled in the high-temperature coolant circulation path 20 and the low-temperature coolant circulation path 30 are both antifreezes such as a general ethylene glycol aqueous solution. The engine cooling device of the present invention is configured to include a high-temperature coolant circulation path 20, a low-temperature coolant circulation path 30, and components related thereto.

  First, the high-temperature coolant circulation path 20 is closed loop so that the coolant in the water jacket 1a of the engine 1 is once taken out and then returned to the outside, and in the middle, a mechanical water pump 21 and a radiator 22 are provided. Are provided at least.

  When the water pump 21 is operated in the high-temperature coolant circulation path 20, the coolant circulates as shown by the solid line arrow 100 in FIGS. In this high-temperature coolant circulation path 20, a region for guiding the coolant taken out from the water jacket 1 a of the engine 1 to the radiator 22 is a coolant introduction part 23, and the coolant is recirculated from the radiator 22 to the water jacket 1 a of the engine 1. The region is a coolant reflux unit 24.

  The water pump 21 is provided downstream of the coolant circulation direction in the coolant circulation part 24 of the high-temperature coolant circulation path 20. The water pump 21 is called a mechanical type, and although not shown, the rotational power of the crankshaft of the engine 1 is transmitted through a power transmission device (including a pulley, a belt, etc.) and driven. . The radiator 22 is a heat exchanger that exchanges heat between the coolant circulating in the high-temperature coolant circulation path 20 and the outside air.

  Next, the low-temperature coolant circulation path 30 is a closed loop so that coolant for cooling the water-cooled intercooler 3 is circulated, and an electric water pump 31 and a radiator are disposed in the middle of the low-temperature coolant circulation path 30. 32 is provided.

  The electric water pump 31 circulates the coolant in the low-temperature coolant circulation path 30. The operation of the water pump 31 is controlled by the following electronic control unit (hereinafter referred to as ECU) 50. The radiator 32 is a heat exchanger that exchanges heat between the coolant circulating in the low-temperature coolant circulation path 30 and the outside air.

  When the water pump 31 is operated in the low-temperature coolant circulation path 30, the coolant circulates as shown by the solid line arrows 200 in FIGS. In this low-temperature coolant circulation path 30, a region for introducing the coolant from the intercooler 3 to the radiator 32 is a coolant introduction part 33, and a region for returning the coolant from the radiator 32 to the intercooler 3 is a coolant return part 34. Has been.

  The low-temperature coolant circulation path 30 of this embodiment is provided with a radiator bypass path 35 for bypassing the radiator 32, and the water jacket 2 b of the supercharger 2 is in series with the radiator bypass path 35. It is connected to the. That is, the coolant flowing through the radiator bypass path 35 can flow through the water jacket 2 b of the supercharger 2.

  Further, in this embodiment, an upstream side communication path 36 for connecting the outlet 1b of the water jacket 1a of the engine 1 and the inlet side portion of the water jacket 2a of the supercharger 2 in the radiator bypass path 35 is connected. Has been. Further, in the radiator bypass path 35, a downstream side communication path 37 for communicating the outlet side portion of the water jacket 2b of the supercharger 2 and the position closer to the radiator 22 in the take-out path 23 of the high-temperature coolant circulation path 20 is provided. It is connected.

  Further, an upstream three-way valve 41 is provided at a connection portion of the upstream communication passage 36 with respect to the radiator bypass passage 35, and a downstream three-way valve 42 is provided at a connection portion of the downstream communication passage 37 with respect to the radiator bypass passage 35. It has been.

  The upstream three-way valve 41 is configured to be switched between a first state and a second state. Specifically, the first state of the upstream three-way valve 41 is a state in which the coolant of the water jacket 1a of the engine 1 is guided to the water jacket 2b of the supercharger 2 through the upstream communication passage 36 and the radiator bypass passage 35. That is. The second state of the upstream three-way valve 41 is a state in which the coolant in the low-temperature coolant circulation path 30 is guided from the radiator bypass path 35 to the water jacket 2b of the supercharger 2.

  The downstream three-way valve 42 is configured to be switched between a first state and a second state. Specifically, the first state of the downstream three-way valve 42 is a state in which the coolant is led from the outlet side of the water jacket 2b of the supercharger 2 to the radiator 22 of the high-temperature coolant circulation path 20 through the downstream flow passage 37. That is. The second state of the downstream side three-way valve 42 is a state in which the coolant is guided from the outlet side of the water jacket 2 b of the supercharger 2 to the coolant introduction part 33 of the low-temperature coolant circulation path 30.

  These two three-way valves 41 and 42 are electromagnetic or electric, and their operations are controlled by the ECU 50. The two three-way valves 41 and 42 constitute “flow path control means” described in the claims.

  The ECU 50 is an engine control computer for controlling various operations of the engine, for example. Although not shown in detail, the ECU 50 has a known configuration including a CPU (central processing unit), a ROM (program memory), a RAM (data memory), a backup RAM (nonvolatile memory), 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 in the CPU, data input from each sensor, and the backup RAM is a non-volatile memory that stores data to be saved when the engine is stopped. It is.

  In this embodiment, the existing ECU 50 is equipped with a function for controlling the operation of the electric water pump 31 and the two three-way valves 41 and 42.

  In this embodiment, a first temperature sensor 43 for detecting the temperature thw1 of the coolant flowing through the outlet 1b of the water jacket 1a of the engine 1 is provided. A second temperature sensor 44 is provided on the discharge side of the water pump 31 to detect the temperature thw2 of the coolant flowing therethrough.

  The first and second temperature sensors 43 and 44 output a signal corresponding to the temperature of the coolant and input it to the ECU 50. For example, the ECU 50 detects the coolant temperature thw1 based on the input of the output signal of the first temperature sensor 43, and determines whether or not the detected coolant temperature thw1 is equal to or less than a predetermined threshold value X. In addition to executing the process of determining whether or not the engine 1 has been warmed up, the coolant temperature thw2 is detected based on the input of the output signal of the second temperature sensor 44, and the detected coolant temperature thw2 is predetermined. By determining whether or not the threshold value Y is equal to or less than the threshold value Y, processing for opening / closing control of the upstream three-way valve 41 and the downstream three-way valve 42 is executed.

  Incidentally, when it is determined that thw2 ≦ Y, the ECU 50 controls the upstream three-way valve 41 and the downstream three-way valve 42 to be in the first state by controlling the first flow path (the one-dot chain line in FIG. 1). On the other hand, when it is determined that thw2> Y, the second flow path (FIG. 2) is controlled by controlling both the upstream three-way valve 41 and the downstream three-way valve 42 to the second state. 2).

  The first flow path is a warm-up flow path for circulating the coolant taken out from the water jacket 1a of the engine 1 through the water jacket 2b of the supercharger 2. When this first flow path is formed, the turbocharger 2 is warmed by the coolant of the engine 1 that rises relatively quickly, so that the turbine shaft support bearing portion of the supercharger 2 (not shown). The viscosity of the lubricating oil becomes relatively low and the lubricity is improved. As a result, it is possible to stabilize the operation of the supercharger 2 such that the friction of the bearing portion is reduced and the oil film damping of the bearing portion is improved.

  The second flow path is a normal temperature control flow path for circulating the coolant in the low-temperature coolant circulation path 30 through the water jacket 2b of the supercharger 2. When this second flow path is formed, the coolant in the low-temperature coolant circulation path 30 passes through the intercooler 3 and the water jacket 2b of the supercharger 2 to recover the heat of the supercharger 2, and then the cooling As the liquid passes through the radiator 32, the recovered heat is released to the atmosphere by the radiator 32, so that the cooling liquid circulating in the low-temperature cooling liquid circulation path 30 does not excessively rise in temperature within a predetermined temperature range. Will be kept.

  Further, with respect to the threshold value Y, the coolant temperature thw2 of the low-temperature coolant circulation path 30 necessary to make the turbine shaft supporting bearing portion (not shown) of the turbocharger 2 have good lubricity. Can be determined by experiments or simulations, and can be set as appropriate (for example, in the range of about 40 to 50 ° C., preferably 50 ° C.) based on the acquired results. By the way, since the upper limit value of the coolant temperature thw2 of the low-temperature coolant circulation path 30 after the engine 1 is warmed up is about 50 ° C., if this is taken into consideration, the threshold value Y is less than the upper limit value. It can be said that it is preferable to do.

  Incidentally, since the coolant circulating in the low-temperature coolant circulation path 30 recovers their heat when passing through the intercooler 3 and the water jacket 2b of the supercharger, the coolant temperature near the inlet side of the radiator 32 is high. However, when the coolant passes through the radiator 32, the heat of the coolant is released to the atmosphere, so that the coolant temperature near the outlet side of the radiator 32 is lowered. That is, the coolant temperature near the inlet side of the radiator 32 in the coolant introduction part 33 of the low-temperature coolant circulation path 30 is the coolant temperature near the outlet side of the radiator 32 in the coolant reflux part 34 of the low-temperature coolant circulation path 30. Higher than

  Next, an example of the operation by the ECU 50 will be described with reference to the flowchart of FIG. The flowchart shown in FIG. 3 is started when the engine 1 is started.

  When this flowchart is started, first, in step S1, both the upstream three-way valve 41 and the downstream three-way valve 42 are brought into the second state. Thereby, the 2nd flow path (refer the dashed-two dotted line arrow 400 of FIG. 2) for distribute | circulating the coolant of the low-temperature coolant circulation path 30 to the water jacket 2b of the supercharger 2 is made.

  In subsequent step S2, the coolant temperature thw2 on the coolant discharge side of the radiator 32 in the low-temperature coolant circulation path 30 is detected based on the input of the output signal from the second temperature sensor 44.

  Thereafter, in step S3, it is determined whether or not the coolant temperature thw2 detected in step S2 is equal to or lower than a predetermined threshold Y.

  Here, when the coolant temperature thw2 exceeds the threshold value Y, that is, when it is not necessary to warm up the supercharger 2, a negative determination is made in step S3, and the process returns to step S2.

  On the other hand, when the coolant temperature thw2 is equal to or lower than the predetermined threshold Y, that is, when the supercharger 2 needs to be warmed up, an affirmative determination is made in step S3, and the process proceeds to step S4.

  In step S4, both the upstream three-way valve 41 and the downstream three-way valve 42 are set to the first state. Thereby, the 1st flow path (refer the dashed-dotted arrow 300 of FIG. 1) for distribute | circulating the cooling fluid taken out from the water jacket 1a of the engine 1 to the water jacket 2b of the supercharger 2 is made.

  In the engine cooling device configured as described above, the supercharger 2 is warmed with the coolant that rises relatively quickly in the water jacket 1a of the engine 1 when the engine 1 is started in a situation where the outside air temperature is low. Thus, the lubricating oil viscosity of the bearing portion (not shown) for supporting the turbine shaft of the turbocharger 2 is lowered as quickly as possible to improve the lubricity.

  As a result, the friction of the supercharger 2 can be reduced, and the operation of the supercharger 2 can be stabilized, for example, the oil film damping of the bearing portion of the supercharger 2 is improved. .

  Moreover, after the supercharger 2 has been warmed up, the supercharger 2 is cooled by circulating the coolant in the low-temperature coolant circulation path 30 through the water jacket 2b of the supercharger 2. The supercharger 2 can be prevented from excessively rising in temperature.

  As described above, it is possible to achieve both stabilization of the operation of the supercharger 2 in a situation where the outside air temperature is low and prevention of excessive temperature rise of the supercharger 2 after the warm-up of the engine 1 is completed.

  In addition, this invention is not limited only to the said embodiment, It can change suitably in the range equivalent to the claim and the said range.

  (1) In the above embodiment, an example is given in which two three-way valves 41 and 42 are used as the flow path control means. However, the present invention is not limited to this, for example, although not shown, for example, a four-way valve It is possible to replace it.

  When such a four-way valve is used, for example, it is possible to create a state in which no coolant flows through the water jacket 2b of the supercharger 2. For example, in a hybrid vehicle in which the engine 1 and an electric motor are combined, power saving is important. Therefore, when the engine cooling device according to the present invention is applied to such a hybrid vehicle, as a stage before performing the warm-up process of the supercharger 2 when the engine 1 is started in a situation where the outside air temperature is low, The supercharger 2 is heated by the exhaust gas of the engine 1 by not allowing the coolant to flow through the water jacket 2b of the supercharger 2 with the four-way valve. It becomes possible to stop the operation of 31. In this way, it is possible to save electric power necessary for the operation of the water pump 31. Then, if the warm-up process of the supercharger 2 is performed after the temperature raising operation by the exhaust gas is performed for a predetermined time, the time required for completing the warm-up of the supercharger 2 can be shortened. Become.

  (2) Although not shown in the above embodiment, the high-temperature coolant circulation path 20 is provided with a radiator bypass path for bypassing the radiator 22, and the heating heat installed in the passenger compartment in the middle of the radiator bypass path Exchangers (heater cores) can be connected in series.

  In this case, for example, when the engine 1 is cold-started, the coolant in the water jacket 1a of the engine 1 is not allowed to flow to the radiator 22 and can be allowed to flow to the radiator bypass. . By doing so, it becomes possible to heat the passenger compartment at a relatively early stage after the engine 1 is cold started.

  The present invention supplies a high-temperature coolant circulation path for taking out and returning the coolant of an engine with a supercharger to the outside, and a water-cooled intercooler for cooling compressed intake air from the compressor of the supercharger It can be suitably used for an engine cooling device including a low-temperature coolant circulation path through which the coolant to be circulated.

DESCRIPTION OF SYMBOLS 1 Engine 1a Water jacket of an engine 2 Supercharger 2a Bearing housing of a supercharger 2b Water jacket of a bearing housing 3 Intercooler 20 High-temperature coolant circulation path 21 Water pump 22 Radiator 23 Coolant introduction part 24 of a high-temperature coolant circulation path Coolant recirculation section of the high-temperature coolant circulation path 30 Low-temperature coolant circulation path 31 Water pump 32 Radiator 33 Coolant introduction section of the low-temperature coolant circulation path 34 Coolant recirculation section of the low-temperature coolant circulation path 35 Radiator bypass path 36 Upstream communication path of the low-temperature coolant circulation path 37 Downstream communication path of the low-temperature coolant circulation path 41 Upstream three-way valve 42 Downstream three-way valve 44 Second temperature sensor 50 ECU

Claims (4)

A high-temperature coolant circulation path for taking out the coolant of the supercharged engine and returning it to the outside;
A low-temperature coolant circulation path through which coolant supplied to a water-cooled intercooler for cooling compressed intake air from the compressor of the supercharger is circulated;
A flow for creating a first flow path for circulating the coolant taken out of the engine through a water jacket provided in the supercharger or a second flow path for circulating the coolant of the low-temperature coolant circulation path through the water jacket. Road control means;
A controller for controlling the operation of the flow path control means,
The engine cooling device, wherein the control section controls the flow path control means so as to create the first flow path when a coolant temperature in the low-temperature coolant circulation path is equal to or lower than a predetermined threshold value. . The engine cooling device according to claim 1, wherein
The control unit controls the flow path control means to create the second flow path when the coolant temperature of the low-temperature coolant circulation path exceeds the predetermined threshold value. Engine cooling device. The engine cooling device according to claim 1 or 2,
The high-temperature coolant circulation path is provided with a water pump for circulating the coolant and a radiator for exchanging heat with the outside of the coolant taken out of the water jacket of the engine,
The low-temperature coolant circulation path includes an electric water pump for circulating the coolant, a radiator for exchanging heat between the circulating coolant and the outside air, bypassing the radiator, and the supercharger on the way A radiator bypass path in which water jackets are connected in series, an upstream side connected to communicate with an outlet of the water jacket of the engine and an inlet side portion of the water jacket of the turbocharger in the radiator bypass path A downstream passage connected to communicate with a communication passage, an outlet side portion of a water jacket of the supercharger in the radiator bypass passage, and a coolant introduction side to the radiator in the high-temperature coolant circulation passage; An engine cooling device comprising a passage. The engine cooling device according to claim 3, wherein
The flow path control means includes an upstream three-way valve installed at a connection portion of the upstream communication path with respect to the radiator bypass passage, and a downstream three-way valve installed at a connection portion of the downstream communication passage with respect to the radiator bypass passage. And a structure including a valve,
The upstream three-way valve has a first state in which coolant in the water jacket of the engine is guided to the water jacket of the supercharger through the upstream communication path and the radiator bypass path, and cooling of the low-temperature coolant circulation path It is configured to be switched to a second state in which liquid is guided from the radiator bypass path to the water jacket of the supercharger,
The downstream three-way valve has a first state in which coolant is guided from the outlet side of the water jacket of the supercharger to the radiator of the high-temperature coolant circulation path through the downstream flow passage, and the water jacket of the supercharger And is configured to be switched to a second state for guiding the coolant from the outlet side to the low-temperature coolant circulation path,
The control unit controls the upstream three-way valve and the downstream three-way valve to be in the first state when making the first flow path, while creating the second flow path, An engine cooling apparatus characterized by controlling both the upstream three-way valve and the downstream three-way valve to be in the second state.

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