JP6529026B2 - Internal combustion engine cooling system - Google Patents

Description

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

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

  In the cooling device for an internal combustion engine of Patent Document 1, cooling water is circulated between the internal combustion engine and the heater core for the room by a water pump, and the heat absorbed by the internal combustion engine is radiated to the room through the heater core for the room. . A flow control valve (flow rate control valve for limiting the amount of cooling water flowing to the indoor heater core, if the temperature of the cooling water is lower than a predetermined temperature, in the middle of the heater core connecting passage for circulating the coolant from the internal combustion engine to the indoor heater core. Variable mechanism) is provided.

Unexamined-Japanese-Patent No. 11-117739

  It is desirable to further miniaturize a flow rate variable mechanism that changes the flow rate of the coolant between an internal combustion engine and a heat exchanger for accessories such as a heater. Since the restriction of the flow of the coolant to the heater by the flow rate variable mechanism is performed by closing the flow passage of the coolant in a state where the coolant is circulated by 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-described circumstances, and one of its objects is to miniaturize a flow rate variable mechanism that changes the flow rate of the coolant between the internal combustion engine and the heat exchanger for accessories An object of the present invention is to provide a cooling system for an internal combustion engine.

  A cooling device for an internal combustion engine according to one aspect of the present invention circulates a coolant between the internal combustion engine and the heat exchanger for auxiliary equipment to absorb heat from the internal combustion engine, and a heat exchanger for auxiliary equipment And heat dissipation. The cooling device for the 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 flow rate variable mechanism changes the flow rate of the coolant between the internal combustion engine and the heat exchanger for auxiliary devices. The pump control unit temporarily stops the electric pump when blocking the flow of the coolant to the accessory heat exchanger. The flow rate control unit limits the flow rate of the coolant by means of the flow rate variable mechanism in conjunction with the stop of the electric pump.

  The above-described cooling device for an internal combustion engine can miniaturize the flow rate variable mechanism. When blocking the flow of coolant to the heat exchanger for accessories, the pump controller stopped the restriction of the amount of flow of coolant between the internal combustion engine and the heat exchanger for accessories, by the pump control unit After that, by controlling the flow rate variable mechanism by the flow rate control unit, it is possible to substantially eliminate the drag of the coolant to the flow rate variable mechanism. The miniaturization of the flow rate variable mechanism contributes to (a) reduction of power consumption of the flow rate variable mechanism and improvement of fuel consumption, (b) contribution to weight reduction, (c) contribution to cost reduction, (d) ) It is easy to suppress the generation of abnormal noise due to water hammer.

FIG. 1 is a schematic configuration view showing a cooling device for an internal combustion engine according to a first embodiment.

  Embodiments 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]
A cooling device 1A for an internal combustion engine according to a first embodiment will be described with reference to FIG. Cooling device 1A for an internal combustion engine circulates coolant C between the internal combustion engine (engine 2) and radiator 3 to absorb heat from engine 2 and to transfer the heat to atmosphere through radiator 3. The engine 2 is cooled by performing heat radiation. Further, the cooling device 1A of the internal combustion engine circulates the cooling fluid C between the internal combustion engine (engine 2) and the heat exchanger for accessories, thereby absorbing the heat from the engine 2 and the heat exchanger for accessories To dissipate heat. The main feature of the cooling device 1A for an internal combustion engine is that the flow rate of the coolant C from the engine 2 to the heat exchanger for accessories when blocking the flow of the coolant C to the heat exchanger for accessories The above limitation is performed after the electric pump 5 for circulating the coolant C is stopped. Hereinafter, after explaining each composition of cooling device 1A of an internal-combustion engine, a control procedure of operation of cooling device 1A of an internal-combustion engine in blocking circulation of cooling fluid C to a heat exchanger for accessories is explained. Here, the cooling device 1A of the internal combustion engine is configured such that the heat exchanger for auxiliary equipment is configured by the heater 4 for the passenger compartment, and the heat of the engine 2 absorbed by the coolant C is used as a heat source for heating the passenger compartment. Will be described by way of example. FIG. 1 shows the flow direction of the coolant C by black arrows, and shows the flow state of the coolant C during warm-up operation and when the heater 4 is in operation.

(Coolant)
The coolant C absorbs the heat of the engine 2 (internal combustion engine) to cool the engine 2. The heat of the engine 2 can be absorbed by the coolant C 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 is radiated to the vehicle interior via the heater 4. The circulation of the coolant C between the engine 2 and the radiator 3 and between the engine 2 and the heater 4 is carried out using the electric pump 5 by using the radiator side circulation passage 30 and the radiator bypass passage 6 and the heater side. This can be done by circulating the circulation passage 40 and the radiator bypass passage 6 (both will be described later). The circulation path of the coolant C by the electric pump 5 is as follows: electric pump 5 → inside the engine 2 (water jacket 211 of cylinder block 21 → water jacket 221 of cylinder head 22) → radiator 3 and heater 4 → electric pump 5. As the coolant C, those containing antifreeze, LLC (long life coolant), and the like can be suitably used.

(Water jacket)
The water jackets 211 and 221 are flow paths of 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 is in communication with the water jacket 211 of the cylinder block 21. An outlet of a radiator bypass passage 6, which will be described later, is in communication with the inlet of the electric pump 5, and the coolant C flowing through the radiator 3 and the heater 4 is returned to the electric pump 5 via the radiator bypass passage 6. The “inlet” and “outlet” mentioned here are described on the basis of “on” and “out” of the coolant C. The “inlet” and “outlet” are the same in the following description. The electric pump 5 is driven by a motor (not shown) without being driven by the rotation of the engine 2. Therefore, control of the operation and stop of the electric pump 5 can be freely performed regardless of the rotational speed of the engine 2. Control of the operation and stop of the electric pump 5 is performed by the pump control unit 50.

(Pump controller)
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 may be matched when the temperature of the engine 2 reaches a predetermined temperature or more after the start of the engine 2 Be As described later, when the electric pump 5 is temporarily stopped by the pump control unit 50 at the time of operation of the engine 2, the timing of operation (re-operation) of the electric pump 5 by the pump control unit 50 is the flow control unit described later When the closing of the flow rate variable mechanism 43 by 44 is completed and the heater side circulation path 40 is interrupted, the timing is adjusted.

  On the other hand, the stop timing of the electric pump 5 by the pump control unit 50 may be interlocked when blocking the flow of the coolant C to the heater 4. The timing of this stop may be, for example, interlocked with the stop of the heater 4 when the coolant C is at or below a predetermined temperature (low temperature). By the interlocking and the closing of the flow rate variable mechanism 43 by the flow rate control unit 44 after stopping the electric pump 5 as described later, the heater 4 is stopped → the electric pump 5 is stopped → the flow rate variable mechanism 43 is closed, Control is performed in the order of The stop timing of the electric pump 5 by the pump control unit 50 is also matched with the stop of the engine 2. The pump control unit 50 is controlled by an ECU (engine control unit). The same applies to the flow rate control unit 44 described later.

(heater)
The heater 4 circulates the coolant C which has absorbed the heat of the engine 2 and radiates the heat into the passenger compartment, thereby warming the passenger compartment. The heater 4 also cools the coolant C in order to dissipate the heat of the coolant C. The heater 4 includes a heater core (heat exchanger: not shown) through which the coolant C flows. Heat dissipation and cooling of the coolant C by the heater 4 are performed by the coolant C flowing through the heater core.

(Heater side circulation path)
The heater-side circulation passage 40 includes a heater-side supply passage 41 for circulating the coolant C from the engine 2 to the heater 4 and a heater-side discharge passage 42 for circulating the heat within the heater 4 and discharging the cooled refrigerant liquid C. And The inlet of the heater side supply passage 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 passage 42 communicates with the heater 4, and the outlet communicates with a radiator bypass passage 6 described later. A flow rate variable mechanism 43 is provided in the heater side circulation passage 40.

(Flow rate variable 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 by an instruction of the flow rate control unit 44 described later. The flow rate variable mechanism 43 includes a suitable valve for opening and closing the heater side circulation path 40, and here is a solenoid valve. The installation location of the flow rate variable mechanism 43 may be either in the middle of the heater side supply passage 41 or in the middle of the heater side discharge passage 42, and here, it is in the middle of the heater side supply passage 41. The flow rate variable mechanism 43 is closed, for example, after start of the engine 2 or after stopping of the pump interlocked with the stop of the heater 4 described above, and the heater side supply passage 41 is interrupted. At the time), the heater side supply passage 41 is opened.

(Flow control unit)
The flow rate control unit 44 controls the opening and closing of the flow rate variable mechanism 43. Thereby, the heater side supply passage 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 opening timing of the flow rate variable mechanism 43 by the flow rate control unit 44 may be interlocked when the temperature of the coolant C becomes high. 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 stop of the electric pump 5 interlocked with the switching to the stop of the heater 4 as described above. Then, the flow rate variable mechanism 43 can be easily closed. When the electric pump 5 is stopped, it is possible to substantially eliminate the resistance to the flow rate changing mechanism 43 by the cooling fluid C flowing through the heater side circulation path 40. The timing at which the flow rate variable mechanism 43 is closed by the flow rate control unit 44 is when the temperature of the coolant C is low when the temperature of the coolant C is low while the heater 4 is stopped, or immediately after the engine 2 is started. Also match.

(Radiator)
The radiator 3 cools the coolant C by circulating the coolant C which has absorbed the heat of the engine 2 and radiating the heat to the atmosphere.

(Radiator circuit)
The radiator circulation passage 30 includes a radiator supply passage 31 for supplying the cooling fluid C from the engine 2 to the radiator 3 and a radiator discharge passage 32 for discharging the cooling fluid C flowing through the radiator 3 from the radiator 3. The inlet of the radiator supply passage 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 passage 32 communicates with the radiator 3, and the outlet communicates with the radiator bypass passage 6.

(Radiator bypass)
When the coolant C is lower than a predetermined temperature, the radiator bypass passage 6 bypasses the flow of the coolant C to the radiator 3 and returns it to the electric pump 5. The coolant C bypassing the radiator 3 facilitates quick adjustment of the coolant C to a predetermined temperature or higher. The inlet of the radiator bypass passage 6 is in communication with the outlet of the heater side discharge passage 42 and the outlet of the radiator side discharge passage 32, and the outlet of the radiator bypass passage 6 is in communication with the electric pump 5. The radiator bypass passage 6 is provided with a thermostat 7 for adjusting the circulation of the cooling fluid C to the radiator 3 and the circulation of the cooling fluid C to the radiator bypass passage 6 without flowing the cooling fluid C to the radiator 3 There is.

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

(Others)
The cooling device 1A of the internal combustion engine can also circulate the coolant C in addition to the radiator 3 and the heater 4, for example, between the engine 2 and the throttle body 8, between the engine 2 and the EGR valve 9, etc. . The throttle body 8 houses a throttle valve (not shown). The EGR valve 9 adjusts the flow rate of exhaust gas to be recirculated to an intake port (not shown) of a cylinder of the engine 2 in 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 or to prevent the throttle valve (butterfly: not shown) from freezing. The circulation of the coolant C between the engine 2 and the EGR valve 9 can cool the EGR valve 9.

  In the circulation of the coolant C between the engine 2 and the throttle body 8, the throttle side supply passage 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 are throttled. It can be performed by the throttle side discharge passage 82 discharged from the body 8. The inlet of the throttle side supply passage 81 communicates with the middle of the heater side supply passage 41, and the outlet thereof communicates with the throttle body 8. Here, the communication point at the inlet of the throttle side supply passage 81 is on the upstream side of the flow variable mechanism 43 in the heater side supply passage 42. The coolant C can be circulated to the throttle body 8 regardless of whether the flow rate variable mechanism 43 is opened or closed. On the other hand, the inlet of the throttle side discharge passage 82 is in communication with the throttle body 8, and the outlet is in the middle of the heater side discharge passage 42. Here, the communication point of the outlet of the throttle side exhaust passage 82 is on the upstream side of the outlet of the EGR valve side exhaust passage 92 here.

  In the circulation of the coolant C between the engine 2 and the EGR valve 9, the EGR side supply passage 91 for supplying the coolant C from the engine 2 to the EGR valve 9 and the coolant C flowing in the EGR valve 9 are It can be performed by the EGR side discharge passage 92 discharged from the valve 9. The inlet of the EGR side supply passage 91 is in communication with the water jacket 221 of the cylinder head 22, and the outlet is in communication with the RGR valve 9. The inlet of the EGR side discharge passage 92 is in communication with a point different from the outlet of the EGR side supply passage 91 in the EGR valve 9, and the outlet is in the middle of the heater side discharge passage 42. Here, the communication point of the outlet of the EGR side discharge passage 92 is on the downstream side of the outlet of the throttle side discharge passage 82 in the heater side discharge passage 42.

(Control procedure)
A control procedure of the operation of the cooling device 1A of 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 device 1A of the internal combustion engine at the time of operation of the heater 4, a control procedure when the heater 4 is stopped will be described.

  When the heater 4 is in operation, the flow rate control mechanism 43 is open by the flow control unit 44, and the heater side circulation passage 40 is open. 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: electric pump 5 → engine 2 → heater side supply path 41 → heater 4 → heater side discharge Path 42 → radiator bypass path 6 → electric pump 5

  When the occupant of the vehicle 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 of the coolant C on the flow rate changing mechanism 43 is substantially eliminated. The flow rate control unit 44 closes the flow rate variable mechanism 43 when the electric pump 5 is stopped. When the closing of the flow rate variable mechanism 43 is completed, the heater side supply passage 41 is disconnected. The pump control unit 50 restarts the electric pump 5 when the closing of the flow rate variable mechanism 43 is completed. After stopping the electric pump 5 by the pump control unit 50, the time (restart time) until reactivation is a short time until the closing of the flow rate variable mechanism 43 is completed, so the influence on the cooling performance of the engine 2 is substantially It is thought that there is not.

  Thereafter, when the heater 4 is operated again, the flow control unit 44 opens the flow rate variable mechanism 43 while the pump control unit 50 operates without stopping the electric pump 5. The opening of the flow rate variable mechanism 43 by the flow rate control unit 44 at the time of circulation of the cooling fluid C is different from that at the time of closing, and no reaction by the cooling fluid C acts.

[Function effect]
In the cooling device 1A of the internal combustion engine described above, when the heater 4 is stopped, the flow control unit 44 can close the flow rate variable mechanism 43 after the pump control unit 50 stops the electric pump 5 in conjunction with the stop. Therefore, when the heater 4 is stopped, the drag of the coolant C to the flow rate variable mechanism 43 can be substantially eliminated. Since the flow rate variable mechanism 43 can be miniaturized along with this, (a) the power consumption of the flow rate variable mechanism 43 can be reduced, which contributes to the improvement of fuel consumption, (b) contributes to weight reduction, and (c) reduction of 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, is shown by the claims, and is intended to include all modifications within the scope and meaning equivalent to the claims. For example, the accessory heat exchanger can be a transmission warmer, an EGR cooler, a sub radiator, or the like.

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

1A Internal combustion engine cooling system C Coolant 2 Engine (internal combustion engine)
Reference Signs List 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 machine)
40 heater side circulation passage 41 heater side supply passage 42 heater side discharge passage 43 flow rate variable mechanism 44 flow control unit 5 electric pump 50 pump control unit 6 radiator bypass passage 7 thermostat 8 throttle body 81 throttle side supply passage 82 throttle side discharge passage 9 EGR valve 91 EGR side supply passage 92 EGR side exhaust passage

Claims (1)

A cooling device for an internal combustion engine, which circulates a coolant between the internal combustion engine and the heat exchanger for accessories, and absorbs heat from the internal combustion engine and dissipates heat through the heat exchanger for accessories. 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 heat exchanger for auxiliary devices;
A pump control unit for temporarily stopping the electric pump when blocking the flow of the cooling fluid to the accessory heat exchanger;
A flow rate control unit that limits the flow rate of the coolant by the flow rate variable mechanism in conjunction with the stop of the electric pump ;
A heater side supply passage for supplying the cooling fluid from the internal combustion engine to the heat exchanger for auxiliary devices, and a heater side discharge passage for discharging the cooling fluid from the heat exchanger for auxiliary devices to the internal combustion engine;
A throttle side supply passage for supplying the coolant from the internal combustion engine to the throttle body, and a throttle side discharge passage for discharging the coolant from the throttle body to the internal combustion engine;
The heater side supply path and the heater side discharge path, and the throttle side supply path and the throttle side discharge path are configured in parallel,
The variable flow mechanism, regardless of opening and closing, said to be able circulate throttle side supply passage and the cooling liquid to the throttle side discharge passage, that provided to the heater side supply path or the heater-side exhaust passage internal combustion Engine cooling system.

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