JP2016191312A - Cooling device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device of an internal combustion engine in which a flow rate variable mechanism for varying a circulation amount of a cooling liquid between the internal combustion engine and an auxiliary heat exchanger can be reduced in size.SOLUTION: A cooling device 1A of an internal combustion engine absorbs heat from an engine 2 and dissipates the heat into a cabin via a heater 4 by making a cooling liquid C circulate between the engine 2 (internal combustion engine) and the indoor heater 4 (auxiliary heat exchanger). The cooling device 1A of the internal combustion engine comprises an electric pump 5, a flow rate variable mechanism 43, a pump control part 50, and a flow rate control part 44. The electric pump 5 makes the cooling liquid C circulate. The flow rate variable mechanism 43 varies a circulation amount of the cooling liquid C between the engine 2 and the heater 4. When blocking the circulation of the cooling liquid to the heater 4, the pump control part 50 temporarily stops the electric pump 5. The flow rate control part 44 limits the circulation amount of the cooling liquid C by the flow rate variable mechanism 43 in conjunction with the stop of the electric pump 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to cooling an internal combustion engine that circulates a coolant between the internal combustion engine and an auxiliary heat exchanger to absorb heat from the internal combustion engine and to dissipate heat through the auxiliary heat exchanger. Relates to the device. In particular, the present invention relates to a cooling device for an internal combustion engine that can downsize a flow rate variable mechanism that varies the flow rate of a coolant between the internal combustion engine and an auxiliary heat exchanger.

  In automobiles, a coolant is circulated between the internal combustion engine (engine) and the radiator to absorb heat from the internal combustion engine and to dissipate the heat to the atmosphere via the radiator. A cooling device for an internal combustion engine for cooling the engine is provided. This cooling device for an internal combustion engine uses a part of the coolant as a heat source for room heating (for example, Patent Document 1).

  The cooling device for an internal combustion engine of Patent Document 1 circulates cooling water between the internal combustion engine and the indoor heater core by a water pump, and radiates heat absorbed by the internal combustion engine into the room through the indoor heater core. . A flow control valve (flow rate) that restricts the flow rate of the cooling water to the indoor heater core when the temperature of the cooling water is equal to or lower than a predetermined temperature in the middle of the communication path to the heater core for circulating the coolant from the internal combustion engine to the indoor heater core. Variable mechanism).

JP-A-11-117739

  There is a demand for further miniaturization of a flow rate variable mechanism that varies the flow rate of the coolant between the internal combustion engine and an auxiliary heat exchanger such as a heater. Since the flow rate of the coolant through the variable flow mechanism is limited by closing the coolant flow path with the coolant flowing through the water pump, the drag is large and the flow rate variable mechanism is small. It was difficult to do.

  The present invention has been made in view of the above circumstances, and one of its purposes is to reduce the size of a variable flow rate mechanism that varies the flow rate of coolant between the internal combustion engine and the heat exchanger for auxiliary equipment. An object of the present invention is to provide a cooling device for an internal combustion engine.

  An internal combustion engine cooling apparatus according to an aspect of the present invention is configured to circulate a coolant between an internal combustion engine and an auxiliary heat exchanger to absorb heat from the internal combustion engine and to add an auxiliary heat exchanger. Heat dissipation. The cooling device for an internal combustion engine includes an electric pump, a flow rate variable mechanism, a pump control unit, and a flow rate control unit. The electric pump circulates the coolant. The variable flow rate mechanism varies the flow rate of the coolant between the internal combustion engine and the auxiliary heat exchanger. The pump control unit temporarily stops the electric pump when blocking the flow of the coolant to the auxiliary heat exchanger. The flow rate control unit limits the flow rate of the coolant by the flow rate variable mechanism in conjunction with the stop of the electric pump.

  In the cooling device for the internal combustion engine, the flow rate variable mechanism can be reduced in size. When blocking the flow of coolant to the heat exchanger for auxiliary equipment, the pump control unit stopped the electric pump to limit the amount of coolant flow between the internal combustion engine and the heat exchanger for auxiliary equipment. This is because the resistance of the coolant to the variable flow rate mechanism can be substantially eliminated by performing the flow rate control unit after controlling the variable flow rate mechanism. By downsizing the variable flow mechanism, (a) the power consumption of the variable flow mechanism can be reduced, contributing to improved fuel efficiency, (b) contributing to weight reduction, (c) contributing to cost reduction, (d ) Easy to suppress the generation of noise caused by water hammer.

1 is a schematic configuration diagram illustrating a cooling device for an internal combustion engine according to a first embodiment.

  An embodiment of a cooling device for an internal combustion engine of the present invention will be described below.

Embodiment 1
[Cooling device for internal combustion engine]
With reference to FIG. 1, a cooling apparatus 1A for an internal combustion engine according to Embodiment 1 will be described. The internal combustion engine cooling device 1 </ b> A circulates a coolant C between the internal combustion engine (engine 2) and the radiator 3, absorbs heat from the engine 2, and absorbs the heat into the atmosphere via the radiator 3. The engine 2 is cooled by performing heat dissipation. The cooling device 1A for the internal combustion engine circulates the coolant C between the internal combustion engine (engine 2) and the heat exchanger for auxiliary equipment to absorb heat from the engine 2 and to heat the auxiliary equipment. Heat dissipation via The main feature of the cooling device 1A for the internal combustion engine is that the flow rate of the coolant C from the engine 2 to the auxiliary heat exchanger when the flow of the coolant C to the auxiliary heat exchanger is blocked. This is because the electric pump 5 that circulates the coolant C is stopped. Hereinafter, after describing each structure of the cooling device 1A for the internal combustion engine, a control procedure for the operation of the cooling device 1A for the internal combustion engine when the flow of the coolant C to the auxiliary heat exchanger is blocked will be described. Here, the cooling apparatus 1A for the internal combustion engine is configured such that the heat exchanger for the auxiliary machine is configured by the heater 4 for the vehicle interior, and the heat of the engine 2 absorbed by the coolant C is used as a heat source for heating the vehicle interior. Will be described as an example. FIG. 1 shows the flow direction of the coolant C with black arrows, and shows the flow state of the coolant C during the warm-up operation and when the heater 4 is in operation.

(Cooling liquid)
The coolant C cools the engine 2 by absorbing heat from the engine 2 (internal combustion engine). The absorption of heat of the engine 2 by the coolant C can be performed by circulating the coolant C through water jackets 211 and 221 (described later) of the engine 2. The coolant C that has absorbed the heat of the engine 2 is cooled by radiating the heat to the atmosphere via the radiator 3 or radiated into the vehicle compartment via the heater 4. The coolant C is circulated between the engine 2 and the radiator 3 and between the engine 2 and the heater 4 by using the electric pump 5, and the radiator side circulation path 30, the radiator bypass path 6, and the heater side. This can be done by circulating each of the circulation path 40 and the radiator bypass path 6 (both will be described later). The circulation path of the coolant C by the electric pump 5 is as follows: the electric pump 5 → in the engine 2 (the water jacket 211 of the cylinder block 21 → the water jacket 221 of the cylinder head 22) → the radiator 3 or the heater 4 → the electric pump 5. As the cooling liquid C, a liquid containing an antifreeze liquid or LLC (long life coolant) can be suitably used.

(Water jacket)
The water jackets 211 and 221 are flow paths for the coolant C. The water jackets 211 and 221 are provided on each of the cylinder block 21 and the cylinder head 22 of the engine 2.

(Electric pump)
The electric pump 5 circulates the coolant C. The coolant C is pumped by the electric pump 5. Here, the outlet of the electric pump 5 communicates with the water jacket 211 of the cylinder block 21. An outlet of a radiator bypass passage 6 (described later) communicates with the inlet of the electric pump 5, and the coolant C that has passed through the radiator 3 and the heater 4 is returned to the electric pump 5 through the radiator bypass passage 6. Here, “inlet” and “outlet” are described based on “in” and “out” of the coolant C. This “entrance” and “exit” are the same in the following description. The electric pump 5 is not driven by the rotation of the engine 2 but is driven by a motor (not shown). Therefore, the operation and stop of the electric pump 5 can be freely controlled regardless of the rotational speed of the engine 2. The pump controller 50 controls the operation and stop of the electric pump 5.

(Pump control unit)
The pump control unit 50 controls the operation and stop of the electric pump 5. For example, the operation timing of the electric pump 5 by the pump control unit 50 may be matched with the start of the engine 2 or when the temperature of the engine 2 becomes equal to or higher than a predetermined temperature after the engine 2 is started. It is done. As will be described later, when the electric pump 5 is temporarily stopped by the pump control unit 50 during operation of the engine 2, the timing of operation (re-operation) of the electric pump 5 by the pump control unit 50 is described later. When the closing of the flow rate variable mechanism 43 by 44 is completed and the heater-side circulation path 40 is disconnected.

  On the other hand, the timing at which the electric pump 5 is stopped by the pump control unit 50 may be linked when the coolant C is prevented from flowing to the heater 4. For example, the timing of this stop is linked to the stop of the heater 4 when the coolant C is below a predetermined temperature (low temperature). As described later, by closing the variable flow rate mechanism 43 by the flow rate control unit 44 after the electric pump 5 is stopped, the heater 4 is stopped, the electric pump 5 is stopped, the flow rate variable mechanism 43 is closed, Control is performed in this order. The timing of stopping the electric pump 5 by the pump control unit 50 is also matched to the stop of the engine 2. The pump control unit 50 is controlled by an ECU (Engine Control Unit). This also applies to the flow rate controller 44 described later.

(heater)
The heater 4 circulates the coolant C that has absorbed the heat of the engine 2 and radiates the heat into the vehicle interior to warm the vehicle interior. Since the heater 4 dissipates the heat of the coolant C, the heater 4 also cools the coolant C. The heater 4 includes a heater core (heat exchanger: not shown) through which the coolant C flows. Heat dissipation / cooling of the coolant C by the heater 4 is performed by circulating the coolant C through the heater core.

(Heater side circulation path)
The heater-side circulation path 40 has a heater-side supply path 41 that allows the coolant C to flow from the engine 2 to the heater 4, and a heater-side discharge path 42 that discharges the coolant liquid C that has flowed through the heater 4 and radiated and cooled. With. The inlet of the heater side supply path 41 communicates (opens) with the water jacket 221 of the cylinder head 22, and the outlet communicates (opens) with the heater 4. The inlet of the heater side discharge path 42 communicates with the heater 4, and the outlet communicates with a radiator bypass path 6 described later. A flow rate variable mechanism 43 is provided in the heater side circulation path 40.

(Variable flow rate mechanism)
The flow rate variable mechanism 43 varies the flow rate of the coolant C between the engine 2 and the heater 4. The above variable of the flow rate variable mechanism 43 is performed according to an instruction from a flow rate control unit 44 described later. The flow rate variable mechanism 43 may be an appropriate valve that opens and closes the heater-side circulation path 40, and is an electromagnetic valve here. The installation location of the flow rate variable mechanism 43 may be in the middle of the heater side supply path 41 and the heater side discharge path 42, and here is in the middle of the heater side supply path 41. The flow rate variable mechanism 43 is closed, for example, when the engine 2 is started or after the pump is stopped in conjunction with the stop of the heater 4 and the heater-side supply path 41 is disconnected. The heater side supply path 41 is opened.

(Flow control unit)
The flow rate control unit 44 controls opening and closing of the flow rate variable mechanism 43. Thereby, the heater side supply path 41 is opened / closed. The above-described control of the flow rate control unit 44 may be performed based on, for example, the temperature of the coolant C and the operation and stop of the heater 4. The timing of opening the flow rate variable mechanism 43 by the flow rate control unit 44 may be interlocked when the coolant C reaches a high temperature. On the other hand, the closing timing of the flow rate variable mechanism 43 by the flow rate control unit 44 is immediately after the electric pump 5 is stopped in conjunction with the switching to the heater 4 being stopped as described above. Then, the flow rate variable mechanism 43 can be easily closed. This is because when the electric pump 5 is stopped, the drag on the flow rate variable mechanism 43 by the coolant C flowing through the heater-side circulation path 40 can be substantially eliminated. The timing of closing the flow rate variable mechanism 43 by the flow rate control unit 44 is when the coolant C becomes low temperature while the heater 4 is stopped or when the temperature of the coolant C is low immediately after the engine 2 is started. Also match.

(Radiator)
The radiator 3 cools the coolant C by circulating the coolant C that has absorbed the heat of the engine 2 and dissipating the heat into the atmosphere.

(Radiator circuit)
The radiator circulation path 30 includes a radiator supply path 31 that supplies the coolant C from the engine 2 to the radiator 3, and a radiator discharge path 32 that discharges the coolant C that has been circulated through the radiator 3 and cooled from the radiator 3. The inlet of the radiator supply path 31 communicates with the water jacket 221 of the cylinder head 22, and the outlet communicates with the radiator 3. The inlet of the radiator discharge path 32 communicates with the radiator 3, and the outlet communicates with the radiator bypass path 6.

(Radiator bypass)
When the coolant C is below a predetermined temperature, the radiator bypass 6 bypasses the flow of the coolant C to the radiator 3 and returns it to the electric pump 5. By allowing the coolant C to bypass the radiator 3, it is easy to quickly adjust the coolant C to a predetermined temperature or higher. The outlet of the radiator bypass path 6 communicates with the outlet of the heater side discharge path 42 and the outlet of the radiator side discharge path 32, and the outlet of the radiator bypass path 6 communicates with the electric pump 5. The radiator bypass 6 is provided with a thermostat 7 that adjusts the flow of the coolant C to the radiator 3 and the flow of the coolant C to the radiator bypass 6 without flowing the coolant C to the radiator 3. Yes.

(thermostat)
The thermostat 7 adjusts the temperature of the coolant C. The thermostat 7 closes the radiator side circulation path 30 so that the cooling liquid C does not flow through the radiator side circulation path 30 when the temperature of the cooling liquid C is lower than the predetermined temperature, and the temperature of the cooling liquid C is equal to or higher than the predetermined temperature. The radiator side circulation path 30 is opened so that the coolant C flows through the radiator side circulation path 30. The opening and closing of the radiator side circulation path 30 by the thermostat 7 may be performed before and after the engine 2 is warmed up. That is, the radiator side circulation path 30 is disconnected before the engine 2 is warmed up, and the radiator side circulation path 30 is opened after the engine 2 is warmed up. The location of the thermostat 7 includes the inlet of the radiator supply path 31 and the outlet of the radiator discharge path 32, and here the outlet of the radiator discharge path 32.

(Other)
In addition to the radiator 3 and the heater 4, the internal combustion engine cooling device 1 </ b> A can also circulate the coolant C between the engine 2 and the throttle body 8 or between the engine 2 and the EGR valve 9, for example. . The throttle body 8 houses a throttle valve (not shown). The EGR valve 9 adjusts the flow rate of exhaust gas recirculated to an intake port (not shown) of a cylinder of the engine 2 in an EGR (exhaust gas recirculation device: not shown). By circulating the coolant C between the engine 2 and the throttle body 8, it is possible to increase the idling speed during warm-up operation and to prevent the throttle valve (butterfly: not shown) from freezing. The EGR valve 9 can be cooled by circulating the coolant C between the engine 2 and the EGR valve 9.

  The coolant C is circulated between the engine 2 and the throttle body 8 by the throttle side supply path 81 for supplying the coolant C from the engine 2 to the throttle body 8 and the coolant C flowing through the throttle body 8 being throttled. This can be done with a throttle side discharge path 82 that discharges from the body 8. The inlet of the throttle side supply path 81 communicates with the heater side supply path 41 and the outlet communicates with the throttle body 8. In this embodiment, the communication part of the inlet of the throttle side supply path 81 is the upstream side of the variable flow mechanism 43 in the heater side supply path 42. Regardless of whether the flow rate variable mechanism 43 is opened or closed, the coolant C can be distributed to the throttle body 8. On the other hand, the inlet of the throttle side discharge path 82 communicates with the throttle body 8, and the outlet communicates with the heater side discharge path 42. Here, the communication point of the outlet of the throttle side discharge path 82 is upstream of the outlet of the EGR valve side discharge path 92.

  The coolant C is circulated between the engine 2 and the EGR valve 9 by the EGR side supply path 91 that supplies the coolant C from the engine 2 to the EGR valve 9 and the coolant C that flows through the EGR valve 9 through the EGR. This can be done with the EGR side discharge path 92 that discharges from the valve 9. The inlet of the EGR side supply path 91 communicates with the water jacket 221 of the cylinder head 22, and the outlet communicates with the RGR valve 9. The inlet of the EGR side discharge path 92 communicates with a location different from the outlet of the EGR side supply path 91 in the EGR valve 9, and the outlet communicates with the heater side discharge path 42. Here, the communication point of the outlet of the EGR side discharge path 92 is set downstream of the outlet of the throttle side discharge path 82 in the heater side discharge path 42.

(Control procedure)
A control procedure of the operation of the cooling device 1A for the internal combustion engine when the heater 4 is stopped during the warm-up operation will be described. After describing the operating state of the cooling apparatus 1A for the internal combustion engine when the heater 4 is operating, the control procedure when the heater 4 is stopped will be described.

  When the heater 4 is in operation, the flow rate control unit 44 opens the flow rate variable mechanism 43 and the heater side circulation path 40 is opened. At this time, since the electric pump 5 is operating, the circulation path of the coolant C between the engine 2 and the heater 4 is the electric pump 5 → the engine 2 → the heater side supply path 41 → the heater 4 → the heater side discharge. The path 42 → the radiator bypass path 6 → the electric pump 5.

  When the vehicle occupant stops the heater 4 in this state, the pump control unit 50 stops the electric pump 5 in conjunction with the stop. At this time, the circulation of the coolant C is immediately stopped, and the drag on the flow rate variable mechanism 43 by the coolant C is substantially eliminated. The flow rate control unit 44 closes the flow rate variable mechanism 43 when the electric pump 5 stops. When the closing of the flow rate variable mechanism 43 is completed, the heater side supply path 41 is disconnected. The pump control unit 50 restarts the electric pump 5 with the completion of the closing of the variable flow rate mechanism 43. After the electric pump 5 is stopped by the pump control unit 50, the time until the re-operation (stop time) is a short time until the closing of the flow rate variable mechanism 43, so the influence on the cooling performance of the engine 2 is substantial. It is thought that there is not.

  Thereafter, when the heater 4 is restarted, the flow controller 44 opens the flow variable mechanism 43 while the pump controller 50 is operating without stopping the electric pump 5. This is because, when the coolant C is circulated, the flow rate control unit 44 opens the flow rate variable mechanism 43 unlike the closed state, so that the drag force by the coolant C does not act.

[Function and effect]
When the heater 4 is stopped, the cooling device 1A for the internal combustion engine described above can close the flow rate variable mechanism 43 by the flow rate control unit 44 after stopping the electric pump 5 by the pump control unit 50 in conjunction with the stop. Therefore, when the heater 4 is stopped, the drag of the coolant C against the flow rate variable mechanism 43 can be substantially eliminated. Accordingly, the flow variable mechanism 43 can be reduced in size, so that (a) the power consumption of the variable flow mechanism 43 can be reduced, contributing to improved fuel consumption, (b) contributing to weight reduction, and (c) reducing cost. (D) It is easy to suppress the generation of noise due to the water hammer.

  The present invention is not limited to these exemplifications, but is defined by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. For example, the auxiliary heat exchanger can be a transmission warmer, an EGR cooler, a sub-radiator, or the like.

  The cooling device for an internal combustion engine of the present invention can be suitably used as a cooling device for cooling an automobile engine.

1A Cooling device for internal combustion engine C Coolant 2 Engine (internal combustion engine)
21 Cylinder block 22 Cylinder head 211, 221 Water jacket 3 Radiator 30 Radiator side circulation path 31 Radiator side supply path 32 Radiator side discharge path 4 Heater (heat exchanger for auxiliary equipment)
DESCRIPTION OF SYMBOLS 40 Heater side circulation path 41 Heater side supply path 42 Heater side discharge path 43 Flow variable mechanism 44 Flow rate control part 5 Electric pump 50 Pump control part 6 Radiator bypass path 7 Thermostat 8 Throttle body 81 Throttle side supply path 82 Throttle side discharge path 9 EGR valve 91 EGR side supply path 92 EGR side discharge path

Claims (1)

A cooling device for an internal combustion engine that circulates a coolant between the internal combustion engine and an auxiliary heat exchanger to absorb heat from the internal combustion engine and to dissipate heat through the auxiliary heat exchanger. There,
An electric pump for circulating the coolant;
A flow rate variable mechanism that varies the flow rate of the coolant between the internal combustion engine and the auxiliary heat exchanger;
A pump controller that temporarily stops the electric pump when blocking the flow of the coolant to the auxiliary heat exchanger;
A cooling device for an internal combustion engine, comprising: a flow rate control unit that restricts a flow rate of the coolant by the flow rate variable mechanism in conjunction with the stop of the electric pump.

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