JP6604540B2 - Engine cooling system - Google Patents

Description

  The present invention relates to an inlet-controlled engine cooling apparatus.

  There are a so-called inlet control method and an outlet control method for controlling the coolant temperature in the engine cooling device mounted on the vehicle (see, for example, Patent Documents 1 and 2).

  An example of the former inlet control type engine cooling system is shown in FIG. In this engine cooling device, the cooling water that has passed through the engine 50 flows through the main radiator 52 and / or the bypass passage 53, and is then supplied again to the engine 50 through the water pump 55 after the flow rate is adjusted by the thermostat 54. It is like that. A part of the cooling water sent out by the water pump 55 passes through the sub-radiator 56 disposed opposite to the main radiator 52 and is then supplied to the intercooler 57 which is a heat exchanger for low water temperature. In addition to the intercooler 57, examples of the low water temperature heat exchanger include an EGR cooler and an air conditioner condenser.

JP 2012-188988 A JP 2007-263034 A

  However, with the recent increase in engine output, not only the engine but also low water temperature heat exchangers such as an intercooler tend to become higher in temperature. There is a risk of reducing fuel consumption or exhaust gas. On the other hand, as the cooling performance of the engine cooling device is improved to lower the cooling water flowing to the low water temperature heat exchanger, the completion of warming up may be delayed when the engine is warmed up.

  Accordingly, an object of the present invention is to provide an inlet-control-type engine cooling apparatus that can improve cooling capacity and promote engine warm-up.

  In order to solve the above problems, an engine cooling device of the present invention includes a main cooling circuit, a flow path switching valve, a water pump, a sub-cooling circuit, a connection flow path, a first on-off valve, and a second on-off valve. The main cooling circuit includes a first flow path that communicates the engine coolant outlet and the cooling water inlet of the main radiator, a second flow path that communicates the cooling water outlet of the main radiator and the engine coolant inlet, A bypass channel that branches from the first branch portion of the one channel and connects to the first junction portion of the second channel. The flow path switching valve is disposed at the first merging portion of the second flow path, and bypasses the engine side flow path on the engine side of the second merging section from the first merging section during warm-up of the engine. During normal operation when the engine has been warmed up, the cooling water flow path is switched so as to communicate with the main radiator side flow path on the main radiator side with respect to the first merging portion of the second flow paths. A water pump is arrange | positioned at the engine side flow path of a 2nd flow path, and pumps cooling water to the cooling water inlet side of an engine. The sub-cooling circuit includes a third flow path that branches from the second branch portion downstream of the water pump of the engine-side flow path of the second flow path and communicates with the cooling water inlet of the sub-radiator, and cooling water of the sub-radiator. Than the 4th flow path which connects the exit and the cooling water inlet of the heat exchanger which cools gas or liquid with cooling water, and the water outlet of the cooling water outlet of the heat exchanger, and the engine side flow path of the 2nd flow path And a fifth flow path connecting the second merging portion on the upstream side. The connection flow path connects the third branch portion of the third flow path of the sub cooling circuit and the third merge portion of the main radiator side flow path of the second flow path of the main cooling circuit. The first on-off valve is disposed in the connection channel. The second on-off valve is disposed closer to the engine coolant inlet side than the second branch part or the second branch part of the second channel of the main cooling circuit, and opens and closes the channel to the engine coolant inlet side. When the flow path switching valve communicates the radiator side flow path and the engine side flow path of the second flow path during normal operation of the engine, the first open / close valve is closed and the second open / close valve is opened. When the flow path switching valve communicates the bypass flow path and the engine flow path of the second flow path during warm-up, the first open / close valve is opened and the second open / close valve is closed.

  In the above configuration, during normal operation of the engine that has been warmed up, the flow path switching valve communicates the main radiator side flow path and the engine side flow path of the second flow path. Flows into the main radiator and is cooled by the main radiator. Further, when the flow path switching valve communicates the radiator side flow path and the engine side flow path of the second flow path during normal operation of the engine, the second on-off valve is opened, so that the cooling cooled by the main radiator is performed. Water flows into the engine and cools the engine.

  Further, when the flow path switching valve communicates the radiator side flow path and the engine side flow path of the second flow path during normal operation of the engine, the first on-off valve is closed, so that the second flow of the main cooling circuit is closed. The cooling water that has flowed into the sub-cooling circuit from the second branch portion of the path flows into the sub-radiator without flowing into the main cooling circuit from the connection flow path, and is further cooled by the sub-radiator, and gas or liquid is passed through the heat exchanger. Cooling.

  Further, when the flow path switching valve communicates with the bypass flow path and the second engine flow path during engine warm-up, the second on-off valve is closed, so that the cooling pressure fed to the water pump is reduced. Water flows into the sub-cooling circuit without flowing into the engine. Thus, since the cooling water does not flow into the engine during the warm-up of the engine, the warm-up of the engine can be promoted.

  Further, when the flow path switching valve communicates between the bypass flow path and the second flow path on the engine side during engine warm-up, the first on-off valve opens, so that the cooling that has flowed into the sub-cooling circuit. The water branches and flows into the sub-radiator side and the connection flow path side at the third branch portion. The cooling water that has flowed to the sub-radiator side at the third branch portion flows into the sub-radiator and is cooled, and the gas or liquid is cooled by the heat exchanger. The cooling water that has flowed to the connection flow path side at the third branch portion flows into the main radiator side flow path of the second flow path and is cooled by the main radiator. In this way, since the cooling water can be cooled using two radiators (main radiator and sub radiator), for example, the cooling water can be cooled at a lower temperature than when cooling water is cooled only by the sub radiator. The cooling performance of the engine cooling device can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, while improving a cooling capability, warming up of an engine can be promoted.

It is a lineblock diagram of the engine cooling device concerning one embodiment of the present invention. It is a block diagram explaining the flow of the cooling water in the engine cooling device during normal operation. It is a block diagram explaining the flow of the cooling water in the engine cooling device during warm-up. It is a block diagram of the engine cooling device which concerns on other embodiment of this invention. It is a block diagram which shows the example of the engine cooling device of the conventional entrance control system.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the figure, the arrow on the cooling circuit indicates the flow direction of the cooling water, and the alternate long and short dash line indicates that there is no cooling water flow. In the valve symbols, white indicates an open state, and black indicates a closed state.

  As shown in FIG. 1, the engine cooling device 10 cools an engine 1 mounted on a vehicle, and uses an inlet control method for temperature control of cooling water. The vehicle is equipped with two radiators (a main radiator 2 and a sub radiator 6) for cooling the cooling water.

  Air A sucked into the intake passage 3 during traveling of the vehicle is compressed by a compressor (not shown) of a turbocharger (not shown) and becomes high temperature, and is cooled by a water-cooled intercooler (heat exchanger) 4. After that, the intake air is supplied to the engine 1 through the intake manifold 5. The intake air supplied to the engine 1 is mixed with fuel and combusted to generate thermal energy, then becomes combustion gas, exhausted from the exhaust manifold 7 to the exhaust passage 8, and then becomes exhaust gas G in the atmosphere. Is released.

  The engine cooling device 10 includes a main cooling circuit 11, a water pump 12, a sub cooling circuit 13, a connection flow path 14, first to third electromagnetic valves 15 to 17, a water temperature sensor 18, and a controller 19.

  The main cooling circuit 11 includes a first flow path 20, a second flow path 21, and a bypass flow path 22. The first flow path 20 communicates the cooling water outlet 1b of the engine 1 through which cooling water flows out and the cooling water inlet 2a of the main radiator 2 through which cooling water flows in. The second flow path 21 communicates the cooling water outlet 2b of the main radiator 2 through which the cooling water flows out and the cooling water inlet 1a of the engine 1 into which the cooling water flows in. The bypass flow path 22 branches from the first branch portion 23 provided in the first flow path 20 and is connected to the first merge section 24 provided in the second flow path 21. A first electromagnetic valve (flow path switching valve) 15 is disposed in the first merging portion 24 of the second flow path 21 of the main cooling circuit 11. The cooling water inlet 2a of the main radiator 2 refers to an opening through which the cooling water flows during a normal operation in which the engine 1 to be described later has been warmed up among the plurality of openings of the main radiator 2.

  The first electromagnetic valve 15 opens and closes the opening of the first merging portion 24 on the main radiator 2 side, and opens and closes the opening of the first merging portion 24 on the bypass flow path 22 side. Can be set. In the bypass state, the first electromagnetic valve 15 closes the opening on the main radiator 2 side of the first merging portion 24 and opens the opening on the bypass flow path 22 side, thereby opening the first flow path 21 in the second flow path 21. Cooling water from the main radiator side flow path 25 on the cooling water outlet 2b side of the main radiator 2 relative to the first merging section 24 to the engine side flow path 26 on the engine 1 (cooling water inlet 1a) side of the first merging section 24 The flow of the cooling water is blocked from the bypass flow path 22 to the engine side flow path 26 (see FIG. 3). In the non-bypass state, the opening of the first merging portion 24 on the main radiator 2 side is opened and the opening on the bypass flow path 22 side is closed, so that the cooling water from the bypass flow path 22 to the engine side flow path 26 is closed. The circulation is blocked, and the circulation of the cooling water from the main radiator side flow path 25 to the engine side flow path 26 is allowed (see FIG. 2). As will be described later, the first electromagnetic valve 15 is controlled by the controller 19 to switch between the bypass state and the non-bypass state, thereby switching the flow path of the cooling water communicating with the engine side flow path 26.

  The water pump 12 is provided in the engine side flow path 26 of the second flow path 21 of the main cooling circuit 11 and is driven by the power of the engine 1 or an electric motor to pump the cooling water.

  The sub-cooling circuit 13 includes a third flow path 27, a fourth flow path 28, and a fifth flow path 29. The third flow path 27 branches from a second branch portion 30 provided between the water pump 12 and the cooling water inlet 1 a of the engine 1 in the engine side flow path 26 of the second flow path 21 of the main cooling circuit 11. To the cooling water inlet 6 a of the sub-radiator 6. The fourth flow path 28 communicates the cooling water outlet 6 b of the sub radiator 6 and the cooling water inlet 4 a of the intercooler 4. The fifth flow path 29 is provided between the cooling water outlet 4 b of the intercooler 4 and the engine side flow path 26 of the second flow path 21 of the main cooling circuit 11 between the first junction 24 and the water pump 12. The 2 junction part 31 is connected. A second electromagnetic valve (second on-off valve) 16 is disposed in the second branch portion 30 of the second flow path 21 of the main cooling circuit 11.

  The second electromagnetic valve 16 opens and closes the opening of the second branch portion 30 on the cooling water inlet 1a side of the engine 1. The second electromagnetic valve 16 circulates the cooling water from the water pump 12 side to the cooling water inlet 1a side of the engine 1 in the closed state in which the opening of the second branch portion 30 on the cooling water inlet 1a side of the engine 1 is closed. Is opened (see FIG. 3), and the cooling water from the water pump 12 side to the cooling water inlet 1a side of the engine 1 is opened in the open state in which the opening of the second branch portion 30 on the cooling water inlet 1a side of the engine 1 is opened. Distribution is permitted (see FIG. 2).

  The connection flow path 14 includes a third branch part 32 provided in the third flow path 27 of the sub cooling circuit 13 and a third merge part provided in the main radiator side flow path 25 of the second flow path 21 of the main cooling circuit 11. 33 is connected. A third electromagnetic valve (first on-off valve) 17 is disposed in the connection flow path 14.

  The third electromagnetic valve 17 opens and closes the connection channel 14. In the open state in which the connection flow path 14 is opened, the third electromagnetic valve 17 allows the coolant to flow between the third branch portion 32 of the sub cooling circuit 13 and the third junction portion 33 of the main cooling circuit 11. However, in the closed state in which the connection flow path 14 is closed, the flow of the cooling water between the third branch part 32 of the sub cooling circuit 13 and the third junction part 33 of the main cooling circuit 11 is blocked. (See FIG. 2).

  The water temperature sensor 18 is disposed in the vicinity of the cooling water outlet 1 b of the engine 1, sequentially detects the temperature of the cooling water of the engine 1 at a position close to the engine 1, and outputs the detected cooling water temperature to the controller 19. In the present embodiment, the water temperature sensor 18 is provided, but other sensors may be used as long as information capable of determining the warm-up state of the engine 1 (whether it is necessary to warm up) can be acquired. Good.

  The controller 19 includes a CPU, a memory, and the like (not shown), and includes a warm-up completion determination unit 34 and a valve control unit 35. When the coolant temperature detected by the water temperature sensor 18 is lower than a predetermined temperature set in advance, the warm-up completion determination unit 34 determines that the engine 1 is warming up (hereinafter simply referred to as warming up). When the cooling water temperature is equal to or higher than the predetermined temperature, it is determined that the engine 1 has been warmed up during normal operation (hereinafter simply referred to as normal operation). That is, the water temperature sensor 18 and the warm-up completion determination unit 34 function as a warm-up completion determination unit that determines whether or not the engine 1 has been warmed up. When the warm-up completion determination unit 34 determines that the warm-up completion determination unit 34 is warming up, the valve control unit 35 sets the first electromagnetic valve 15 to the bypass state and sets the second electromagnetic valve 16 to the closed state. Then, the third electromagnetic valve 17 is set to the open state. On the other hand, when the warm-up completion determination unit 34 determines that the warm-up completion determination unit 34 is operating normally, the valve control unit 35 sets the first electromagnetic valve 15 to the non-bypass state and opens the second electromagnetic valve 16. The third electromagnetic valve 17 is set to the closed state.

  Next, the flow of cooling water during normal operation and warm-up will be described with reference to FIGS.

  During normal operation, as shown in FIG. 2, the first electromagnetic valve 15 is in the non-bypass state, the second electromagnetic valve 16 is in the open state, and is controlled by the valve control unit 35 of the controller 19. The electromagnetic valve 17 is closed. The cooling water pumped to the water pump 12 branches at the second branch portion 30 of the second flow path 21. The cooling water that has flowed to the engine 1 side at the second branch portion 30 flows into the engine 1 from the cooling water inlet 1 a of the engine 1 and cools the engine 1. Cooling water that has been cooled to a high temperature by cooling the engine 1 flows out from the cooling water outlet 1b of the engine 1 and flows into the main radiator 2, is cooled by the main radiator 2, and returns to the water pump 12 for circulation. On the other hand, the cooling water that has flowed into the third flow path 27 of the sub-cooling circuit 13 in the second branch section 30 flows into the sub-radiator 6 and is further cooled and flows into the intercooler 4, and is compressed by the turbocharger to increase the temperature. After cooling the air A, the air A is circulated back to the second junction 31 on the upstream side of the water pump 12 of the main cooling circuit 11.

  On the other hand, during warm-up, as shown in FIG. 3, the first electromagnetic valve 15 is in the bypass state, the second electromagnetic valve 16 is in the closed state, and is controlled by the valve control unit 35 of the controller 19. 3 electromagnetic valve 17 is open. The cooling water pumped to the water pump 12 flows to the third flow path 27 of the sub-cooling circuit 13 at the second branch portion 30 of the second flow path 21 and branches at the third branch portion 32 of the third flow path 27. . The cooling water that has flowed to the connection flow path 14 side at the third branch portion 32 flows into the main radiator 2 from the cooling water outlet 2b, which is the outlet of the cooling water, during normal traveling, and is cooled by the main radiator 2 and travels normally. It flows out from the cooling water inlet 2a which is the cooling water inlet. The cooling water that has flowed out of the main radiator 2 flows from the first branch portion 23 of the first flow path 20 through the bypass flow path 22 and returns to the water pump 12 to circulate. On the other hand, the cooling water that has flowed to the sub-radiator 6 side at the third branch portion 32 flows into the sub-radiator 6 and is further cooled and flows into the intercooler 4 and is compressed by the turbocharger, as in the normal operation. After cooling the heated air A, it returns to the second merging portion 31 upstream of the water pump 12 of the main cooling circuit 11 and circulates.

  In the engine cooling device 10 configured as described above, the second electromagnetic valve 16 is closed during warm-up, and the cooling water pumped to the water pump 12 does not flow into the engine 1. Warm-up can be promoted.

  Further, during the warm-up, the main radiator 2 is used for cooling the intercooler 4 in addition to the sub-radiator 6, so that the cooling performance of the engine cooling device 10 (as compared to the case where only the sub-radiator 6 is used for cooling the intercooler 4 ( In particular, the cooling performance on the side of the sub cooling circuit 13) can be improved.

  Therefore, according to the present embodiment, the cooling capacity can be improved and the warm-up of the engine 1 can be promoted.

  Further, since the cooling water does not flow into the engine 1 during the warm-up, the work amount of the water pump 12 can be suppressed correspondingly, and the lost horsepower can be reduced and the fuel consumption can be improved.

  The heat exchanger to be cooled by the sub-cooling circuit 13 is not limited to the intercooler 4 and may be an EGR cooler, an air conditioner condenser, or the like.

  Further, the valves arranged in the first junction 24 of the second flow path 21, the second branch 30 of the second flow path 21, and the connection flow path 14 are not limited to the electromagnetic valves 15 to 17. For example, an electric valve driven by a motor may be used.

  Further, the valve that blocks the inflow of the cooling water to the engine 1 at the time of warm-up is not limited to the second electromagnetic valve 16 disposed in the second branch portion 30 of the second flow path 21.

  For example, as shown in FIG. 4, the second branch part 30 of the second flow path 21 is not provided with the second electromagnetic valve 16, and the second branch part 30 of the second flow path 21 and the coolant inlet of the engine 1 are provided. You may provide the thermostat 40 between 1a. The thermostat 40 has a valve that opens and closes by wax that expands or contracts according to the temperature of the cooling water, and opens and closes a flow path between the second branch portion 30 and the cooling water inlet 1 a of the engine 1. That is, the thermostat 40 opens and closes the flow path between the second branch portion 30 and the coolant inlet 1 a of the engine 1 without being controlled by the controller 19. The characteristics of the wax are preset so that the temperature of the cooling water flowing from the water pump 12 side (the second branch portion 30 side) melts and expands at a target valve opening temperature described later. The thermostat 40 is closed when the temperature of the cooling water flowing from the water pump 12 side is lower than the target valve opening temperature, and the cooling water from the second branch portion 30 side to the cooling water inlet 1a side of the engine 1 is closed. Block distribution. On the other hand, in the thermostat 40, when the temperature of the cooling water flowing from the water pump 12 side rises and reaches the target valve opening temperature, the wax gradually expands and opens, and the engine 1 from the second branch part 30 side opens. The cooling water is allowed to flow toward the cooling water inlet 1a. When the controller 19 determines that the warm-up completion determination unit 34 is in normal operation, the valve control unit 35 sets the first electromagnetic valve 15 to the non-bypass state and sets the second electromagnetic valve 16 to the open state. To do. The target valve opening temperature at which the thermostat 40 opens is determined by the warm-up completion determination unit 34 being in normal operation, the valve control unit 35 sets the first electromagnetic valve 15 to the non-bypass state, and the second After setting the electromagnetic valve 16 to the open state, the temperature is set to a temperature at which the thermostat 40 can be opened early. For example, the temperature of the cooling water flowing from the water pump 12 side after the valve control unit 35 sets the first electromagnetic valve 15 to the non-bypass state and the second electromagnetic valve 16 to the open state The target valve opening temperature is set based on the calculated temperature calculated by simulation or the like. As shown by a two-dot chain line in FIG. 4, the thermostat 40 has a heater that generates heat when energized to melt and expand the wax, and the heater is controlled by the controller 19 as in the above embodiment. An electronically controlled thermostat may be used.

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to the content of the said embodiment, Of course, it can change suitably in the range which does not deviate from this invention. That is, it is needless to say that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

1: Engine 1a: Engine cooling water inlet 1b: Engine cooling water outlet 2: Main radiator 2a: Main radiator cooling water inlet 2b: Main radiator cooling water outlet 4: Intercooler (heat exchanger)
6: Sub radiator 6a: Sub radiator cooling water inlet 6b: Sub radiator cooling water outlet 10: Engine cooling device 11: Main cooling circuit 12: Water pump 13: Sub cooling circuit 14: Connection flow path 15: First electromagnetic Valve (flow path switching valve)
16: Second electromagnetic valve (second on-off valve)
17: Third electromagnetic valve (first on-off valve)
20: 1st flow path 21: 2nd flow path 22: Bypass flow path 23: 1st branch part 24: 1st junction part 25: Main radiator side flow path 26: Engine side flow path 27: 3rd flow path 28: 4th flow path 29: 5th flow path 30: 2nd branch part 31: 2nd junction part 32: 3rd branch part 33: 3rd junction part 40: Thermostat

Claims (1)

A first flow path that communicates the cooling water outlet of the engine and a cooling water inlet of the main radiator; a second flow path that communicates the cooling water outlet of the main radiator and the cooling water inlet of the engine; and the first flow A main cooling circuit having a bypass flow path branched from the first branch portion of the path and connected to the first merge portion of the second flow path;
The engine-side passage on the engine side with respect to the first joining portion of the second passages is disposed in the first joining portion of the second passage, and the bypass is provided during warm-up of the engine. During normal operation when the engine has been warmed up, the cooling water is communicated with the main radiator side channel on the main radiator side of the second merging portion in the second channel. A flow path switching valve for switching the flow path;
A water pump that is disposed in the engine side flow path of the second flow path and pumps cooling water to the cooling water inlet side of the engine;
A third flow path that branches from a second branch portion downstream of the water pump in the engine-side flow path of the second flow path and communicates with a cooling water inlet of the sub-radiator; and a cooling water outlet of the sub-radiator And a water passage in the engine-side flow path of the second flow path, a fourth flow path communicating with the cooling water inlet of the heat exchanger that cools the gas or liquid with the cooling water, and the cooling water outlet of the heat exchanger A sub-cooling circuit having a fifth flow path connecting the second confluence portion on the upstream side of the pump;
A connection flow path for connecting the third branch portion of the third flow path of the sub-cooling circuit and the third merging portion of the main radiator-side flow path of the second flow path of the main cooling circuit;
A first on-off valve disposed in the connection flow path;
The second cooling section of the main cooling circuit is arranged closer to the cooling water inlet side of the engine than the second branching section or the second branching section, and opens and closes the flow path to the cooling water inlet side of the engine A second on-off valve that
When the flow path switching valve communicates the radiator side flow path and the engine side flow path of the second flow path during the normal operation of the engine, the first on-off valve is closed and the second When the on-off valve is opened and the passage switching valve communicates the bypass passage with the engine-side passage of the second passage during the warm-up of the engine, the first on-off valve is The engine cooling device, wherein the second on-off valve is opened to close.

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