JP2002327671A - Internal combustion engine with heat storage device - Google Patents

Abstract

(57) Abstract: Provided is a technique capable of preventing an excessive consumption of energy stored in a power storage means such as a battery in an internal combustion engine provided with a heat storage device and performing a suitable heat storage. A heat storage means, a heat supply means for supplying a heat medium stored in the heat storage means to an internal combustion engine, a power storage means for storing energy, a heating means for heating the heat medium, and an internal combustion engine. A consumption limit calculating unit 22 for calculating an amount of energy that can be consumed by the heating unit 32 based on the operation time of the engine 1. The heating unit 32 has a range of the amount of energy that can be consumed calculated by the consumption limit calculating unit 22. The heating of the heat medium is performed in the inside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an internal combustion engine provided with a heat storage device.

[0002]

2. Description of the Related Art Generally, when an internal combustion engine is operated in a state in which the temperature around a combustion chamber has not reached a predetermined temperature, that is, in a so-called cold state, the fuel supplied to the combustion chamber becomes difficult to atomize and the combustion becomes difficult. Since extinction occurs near the wall surface of the room, the startability is reduced and the exhaust emission is deteriorated.

Therefore, a heat storage device is provided for storing heat generated during operation of the internal combustion engine and supplying the stored heat to the internal combustion engine when the engine is stopped or when the engine is started to increase the temperature of the internal combustion engine. Internal combustion engines are known. However, in order to improve emission performance and fuel efficiency immediately after starting the internal combustion engine, heat is supplied to the internal combustion engine before starting the internal combustion engine, and the internal combustion engine is heated to a predetermined temperature when the internal combustion engine is started. It is necessary to reach the above.

However, since the timing of starting the internal combustion engine differs depending on the situation, if the time until the internal combustion engine starts after the heat is supplied from the heat storage device becomes longer, the heat supplied to the internal combustion engine becomes longer. Is released into the atmosphere,
The temperature of the internal combustion engine gradually decreases. Also, since heat is released from the heat storage device to a small amount to the outside, if the internal combustion engine is not operated for a long time, the heat stored in the heat storage device decreases, and it is difficult to raise the internal combustion engine to a predetermined temperature. May be caused.

To solve such a problem, for example, Japanese Patent No. 25
In JP 76488, a heater such as an electric heater is provided outside a heat-insulating tank so that cold water in the heat-insulating tank can be heated, and cooling water for supplying hot water from a heat-insulating tank and cooling water to a heat-insulating tank. There is disclosed a hot water supply device capable of concentrating a water passage at one location at the bottom of an insulated tank to minimize heat leakage from the insulated tank.

[0006]

The above-mentioned conventional hot water supply apparatus requires a considerable amount of power supply to the electric heater or the like in order to perform heating by the electric heater or the like. In consideration of the mounting of the heat storage device on the vehicle, it is preferable that the power supply to the electric heater and the like be performed from a battery mounted on the vehicle. This battery stores energy generated from the internal combustion engine during operation of the internal combustion engine, and can take it out as electrical energy when necessary. Then, even when the internal combustion engine is stopped, power can be supplied to the electric heater and the like.

However, since the amount of electricity that can be stored in the battery is limited, if heating by an electric heater or the like is performed for a long time, the energy stored in the battery is excessively consumed, and the internal combustion engine is started. At times, power cannot be supplied to the starter motor, the ignition plug, and the like, which may affect the startability of the internal combustion engine.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is suitable for an internal combustion engine equipped with a heat storage device while preventing excessive consumption of energy stored in power storage means such as a battery. An object is to provide a technology capable of storing heat.

[0009]

Means for Solving the Problems To achieve the above object, an internal combustion engine provided with a heat storage device of the present invention employs the following means. That is, heat storage means for storing heat of the heat medium,
Heat supply means for supplying the heat medium stored in the heat storage means to the internal combustion engine; power storage means for storing energy generated during operation of the internal combustion engine; and energy supplied from the power storage means and stored in the heat storage means. Heating means for heating the heated heat medium, and consumption limit calculation means for calculating the amount of energy that can be consumed by the heating means based on the operation time of the internal combustion engine, wherein the heating means comprises the consumption limit calculation means Is characterized in that the heating of the heat medium is performed within the range of the consumable energy amount calculated by.

The most significant feature of the present invention is that in an internal combustion engine equipped with a heating means for heating the heat medium of the heat storage device using the energy stored in the heat storage means, the minimum necessary for starting the internal combustion engine or the like is provided. The point is to heat the heat medium of the heat storage device to the maximum while securing the minimum energy in the power storage means.

In the internal combustion engine provided with the heat storage device configured as described above, heat generated during operation of the internal combustion engine is stored in the heat storage means even after the operation of the internal combustion engine is stopped. The heat stored by the heat storage means is supplied to the internal combustion engine via a heat medium when the internal combustion engine is cold started. When such heat is supplied, even when the internal combustion engine is cold started, the internal combustion engine is warmed up early.

At this time, if the amount of heat stored in the heat storage means becomes small, it becomes impossible to supply a sufficient amount of heat from the heat storage means to the internal combustion engine, so that the heating means uses the heat medium stored in the heat storage means. Appropriate heating is performed to increase the amount of heat stored in the heat storage means.

By the way, since the heating means heats the heat medium using the energy stored in the heat storage means, if the heating means heats the heating medium indiscriminately, the energy of the power storage means becomes excessive. Will be consumed.

Therefore, the internal combustion engine provided with the heat storage device according to the present invention is provided with a consumption limit calculating means for calculating the amount of energy that can be consumed by the heating means, so as to limit the amount of energy consumed by the heating means.

In this case, the heating means heats the heat medium within the range of the energy amount calculated by the consumption limit calculating means, so that the energy stored in the power storage means may be excessively consumed. Disappears.

As a result, the heat storage amount of the heat storage means is maximized within a range in which the necessary minimum energy amount to be stored in the power storage means can be secured.

Here, since the amount of energy stored in the power storage means has a correlation with the operating time of the internal combustion engine, the consumption limit calculating means calculates the amount of energy that can be consumed by the heating means by calculating the operating time of the internal combustion engine. It may be used as a parameter, and more specifically, the amount of energy that can be consumed by the heating means, using the amount of energy stored in the power storage means before the previous start of the internal combustion engine and the last operation time of the internal combustion engine as parameters. The amount may be calculated.

According to the present invention, there is provided a heat medium temperature measuring means for measuring a temperature of the heat medium stored in the heat storing means, wherein the heating means measures the temperature of the heat medium while the internal combustion engine is stopped. The heating medium may be heated for a predetermined time each time the temperature becomes equal to or lower than a predetermined temperature, and the heating may be stopped when the total energy consumption during stoppage of the internal combustion engine becomes larger than the calculation result of the consumption limit calculation means. With this configuration, the heat medium can be maintained at a predetermined temperature or higher within the range of the amount of energy that can be consumed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of a heat storage device for an internal combustion engine according to the present invention will be described below with reference to the drawings. Here, a case where the heat storage device for an internal combustion engine according to the present invention is applied to a gasoline engine for driving a vehicle will be described as an example.

FIG. 1 is a schematic configuration diagram showing an engine 1 to which a heat storage device for an internal combustion engine according to the present invention is applied, and cooling water passages (circulation passages) A, B, and C through which cooling water circulates. The arrow shown in the circulation passage is the direction of flow of the cooling water when the engine 1 is operating.

The engine 1 shown in FIG. 1 is a water-cooled four-cycle gasoline engine.

The outer shell of the engine 1 includes a cylinder head 1
a, a cylinder block 1b connected to a lower portion of the cylinder head 1a, and an oil pan 1c connected to a lower portion of the cylinder block 1b.

The cylinder head 1a and the cylinder block 1b are provided with a water jacket 23 as a passage for circulating cooling water. At the inlet of the water jacket 23, a water pump 6 for sucking cooling water from outside the engine 1 and discharging the cooling water into the engine 1 is provided. The water pump 6 is a pump that operates using the rotation torque of the output shaft of the engine 1 as a drive source. That is, the water pump 6 operates only when the engine 1 is operating. Further, the engine 1 is provided with an in-engine cooling water temperature sensor 29 for transmitting a signal corresponding to the temperature of the cooling water in the water jacket 23.

The passage for circulating the cooling water through the engine 1 is divided into a circulation passage A for circulating the radiator 9, a circulation passage B for circulating the heater core 13, and a circulation passage C for circulating the heat storage device 10. Some of the circulation passages have portions shared with other circulation passages.

The circulation passage A mainly has a function of lowering the temperature of the cooling water by releasing the heat of the cooling water from the radiator 9.

The circulation passage A is a radiator inlet side passage A.
1, a radiator outlet side passage A2, a radiator 9, and a water jacket 23. Cylinder head 1
a is connected to one end of a radiator inlet side passage A1;
The other end of the radiator entrance side passage A1 is connected to the entrance of the radiator 9.

One end of a radiator outlet side passage A2 is connected to the outlet of the radiator 9, and the radiator outlet side passage A2
The other end of 2 is connected to the cylinder block 1b. A thermostat 8 is provided on the radiator outlet side passage A2 from the outlet of the radiator 9 to the cylinder block 1b when the temperature of the cooling water reaches a predetermined temperature.
Also, the radiator outlet side passage A2 and the cylinder block 1
b is connected via the water pump 6.

The circulation passage B mainly has a function of increasing the ambient temperature of the vehicle cabin by releasing the heat of the cooling water from the heater core 13.

The circulation passage B is a passage B on the inlet side of the heater core.
1, a heater core outlet side passage B2, a heater core 13, and a water jacket 23. One end of the heater core inlet side passage B1 is connected to a point in the radiator inlet side passage A1. A part of the heater core inlet side passage B1 from the cylinder head 1a to this connection portion is shared with the radiator inlet side passage A1. The other end of the heater core inlet side passage B <b> 1 is connected to the inlet of the heater core 13. A shutoff valve 31 that opens and closes in response to a signal from the ECU 22 is interposed in the middle of the heater core entrance side passage B1. One end of the heater core outlet side passage B2 is connected to the outlet of the heater core 13, and the other end of the heater core outlet side passage B2 is connected between the thermostat 8 and the water pump 6 in the middle of the radiator outlet side passage A2. . The passage from this connection to the cylinder block 1b and the water jacket 23 are shared with the radiator outlet side passage A2.

The circulation passage C mainly stores the heat of the cooling water,
Further, it has a function of discharging the stored heat to warm the engine 1.

The circulation passage C includes a heat storage device inlet-side passage C1,
It comprises a heat storage device outlet side passage C2, a heat storage device 10, and a water jacket 23. Heat storage device inlet side passage C1
Is connected in the middle of the heater core outlet side passage B2. The passage from the cylinder head 1a to this connection is
Shared with the circulation passages A and B. On the other hand, the other end of the heat storage device entrance-side passage C <b> 1 is connected to the inlet of the heat storage device 10.
One end of the heat storage device outlet-side passage C2 is connected to the outlet of the heat storage device 10, and the other end of the heat storage device outlet-side passage C2 is connected in the middle of the radiator inlet-side passage A1. Engine 1
Inside the circulation passages A and B and the water jacket 2
Part 3 is shared. A check valve 11 is provided at the inlet and outlet of the heat storage device 10 to allow the cooling water to flow only in the direction of the arrow in FIG. Inside the heat storage device 10, a cooling water temperature sensor 28 in the heat storage device that transmits a signal according to the temperature of the cooling water stored in the heat storage device is provided. Further, in the middle of the heat storage device inlet side passage C1 and upstream of the check valve 11, an electric water pump 12 is provided.
Is interposed.

In the heat storage device 10, a vacuum heat insulating space is provided between the outer container 10a and the inner container 10b, and a cooling water injection pipe through which cooling water flows when the cooling water flows into the heat storage device 10. 10c, a cooling water discharge pipe 10d through which the cooling water flows when flowing out, a heater 32, and a cooling water temperature sensor 28 in the heat storage device are provided.

In the circulating passage thus constructed, in the circulating passage A, when the engine 1 is operating, the rotational torque of the crankshaft (not shown)
The water pump 6 discharges the cooling water at a pressure corresponding to the rotational torque transmitted from the crankshaft to the input shaft of the water pump 6. on the other hand,
Since the water pump 6 stops while the engine 1 is stopped, the cooling water does not circulate in the circulation passage A.

The cooling water discharged from the water pump 6 flows through the water jacket 23. At this time, heat is transferred between the cooling water and the cylinder head 1a and the cylinder block 1b. Part of the heat generated by the combustion inside the cylinder 2 is transmitted to the wall surface of the cylinder 2, and furthermore, the cylinder head 1a and the cylinder block 1b
, The temperature of the entire cylinder head 1a and the cylinder block 1b rises. Part of the heat transmitted to the cylinder head 1a and the cylinder block 1b is transmitted to the cooling water inside the water jacket 23, and raises the temperature of the cooling water. Further, the temperatures of the cylinder head 1a and the cylinder block 1b that have lost the heat decrease.
Thus, the cooling water whose temperature has increased flows out of the cylinder block 1b to the radiator inlet side passage A1.

The cooling water flowing out of the radiator inlet side passage A1 flows into the radiator 9 after flowing through the radiator inlet side passage A1. In the radiator 9, heat exchange is performed between the outside air and the cooling water. Part of the heat of the cooling water having a higher temperature is transmitted to the wall surface of the radiator 9 and further transmitted inside the radiator 9 to increase the temperature of the entire radiator 9. Part of the heat transmitted to the radiator 9 is transmitted to the outside air and raises the temperature of the outside air. In addition, the temperature of the cooling water that has lost the heat decreases accordingly. Thereafter, the cooling water whose temperature has decreased flows out of the radiator 9.

The cooling water flowing out of the radiator 9 flows through the radiator outlet side passage A2 and reaches the thermostat. Here, when the temperature of the cooling water flowing through the heater core outlet side passage B2 reaches a predetermined temperature, the thermostat 8 automatically opens due to thermal expansion of the built-in wax.
That is, if the temperature of the cooling water flowing through the heater core outlet side passage B2 has not reached the predetermined temperature, the radiator outlet side passage A2 is shut off, and the cooling water inside the radiator outlet side passage A2 does not pass through the thermostat 8. Can not.

When the thermostat 8 is open, the cooling water having passed through the thermostat 8 flows into the water pump 6.

Thus, only when the temperature of the cooling water becomes high, the thermostat 8 opens and the cooling water circulates through the radiator 9. The cooling water whose temperature has decreased in the radiator 9 is discharged from the water pump 6 to the water jacket 23, and the temperature rises again.

On the other hand, part of the cooling water flowing through the radiator inlet side passage A1 flows into the heater core inlet side passage B1.

The cooling water flowing into the heater core inlet side passage B1 flows through the heater core inlet side passage B1 and reaches the shutoff valve 31. The shutoff valve 31 is opened during operation of the engine 1 and closed when the engine 1 is stopped, based on a signal from the ECU 22. While the engine 1 is running,
The cooling water passes through the shutoff valve 31 and passes through the heater core inlet side passage B.
1 and reaches the heater core 13.

The heater core 13 exchanges heat with air in the vehicle interior, and the air heated by the movement of the heat is circulated in the vehicle interior by a blower (not shown), and the ambient temperature of the vehicle interior rises. Thereafter, the cooling water flows out of the heater core 13, flows through the heater core outlet side passage B2, and merges with the radiator outlet side passage A2. At this time, when the thermostat 8 is open, it joins the cooling water flowing through the circulation passage A and flows into the water pump 6. On the other hand, when the thermostat 8 is closed, the cooling water flowing through the circulation passage B flows into the water pump 6.

The cooling water whose temperature has dropped in the heater core 13 is discharged from the water pump 6 to the water jacket 23 again.

The engine 1 configured as described above is provided with an electronic control unit (ECU: Electronic Control Unit) 22 for controlling the engine 1. The ECU 22 controls the operating state of the engine 1 according to the operating conditions of the engine 1 and a request from the driver,
Further, this unit is a unit that performs a temperature rise control of the engine 1 (engine preheat control) while the operation of the engine 1 is stopped.

Various sensors such as a crank position sensor 27, a cooling water temperature sensor 28 in a heat storage device, and a cooling water temperature sensor 29 in an engine are connected to the ECU 22 via electric wiring.
2 is input.

The ECU 22 includes the electric water pump 12,
These are connected to the electric water pump 12, the shut-off valve 31, and the like via electric wiring so that the shut-off valve 31 and the like can be controlled.

Here, as shown in FIG.
Are CPs interconnected by a bidirectional bus 350
A U351, a ROM 352, a RAM 353, a backup RAM 354, an input port 356, and an output port 357 are provided, and an A / D converter (A / D) 355 connected to the input port 356 is provided.

The input port 356 inputs the output signals of a sensor that outputs a digital signal, such as the crank position sensor 27, and converts those output signals to C.
The data is transmitted to the PU 351 and the RAM 353.

The input port 356 is connected to the coolant temperature sensor 28 in the heat storage device, the coolant temperature sensor 29 in the engine,
Like the battery 30 or the like, the input is performed via an A / D 355 of a sensor that outputs a signal in an analog signal format, and the output signal is transmitted to the CPU 351 or the RAM 353.

The output port 357 is connected to the electric water pump 12, the shut-off valve 31 and the like via electric wiring.
The control signal output from the CPU 351 is transmitted to the electric water pump 12, the shutoff valve 31, and the like.

The ROM 352 stores application programs such as an engine preheating control routine for supplying heat from the heat storage device 10 to the engine 1 and a cooling water heating control routine by the heater 32.

The ROM 352 stores various control maps in addition to the above-described application programs. The control map includes, for example, a fuel injection amount control map indicating a relationship between an operating state of the engine 1 and a basic fuel injection amount (basic fuel injection time), and a fuel indicating a relationship between an operating state of the engine 1 and a basic fuel injection timing. An injection timing control map and the like.

The RAM 353 stores an output signal from each sensor, a calculation result of the CPU 351 and the like. The calculation result is, for example, an engine speed calculated based on a time interval at which the crank position sensor 27 outputs a pulse signal. These data are rewritten to the latest data every time the crank position sensor 27 outputs a pulse signal.

The backup RAM 354 is a nonvolatile memory capable of storing data even after the operation of the engine 1 is stopped. The operation time of the engine 1 and the like are stored.

Next, an outline of the temperature rise control of the engine 1 (hereinafter referred to as "engine preheat control") will be described.

When the ECU 22 sends a signal to the electric water pump 12 during operation of the engine 1 to operate the electric water pump 12, the cooling water circulates in the circulation passage C.

A part of the cooling water flowing through the heater core outlet side passage B2 flows into the heat storage device inlet side passage C1, and flows through the heat storage device inlet side passage C1 so as to flow through the electric water pump 1.
Reach 2. The electric water pump 12 includes an ECU 22
The cooling water is discharged at a predetermined pressure.

The cooling water discharged from the electric water pump 12 flows through the heat storage device inlet side passage C1 and passes through the check valve 11
And reaches the heat storage device 10. Cooling water injection pipe 10
The cooling water flowing into the heat storage device 10 from c flows out of the heat storage device from the cooling water discharge pipe 10d.

The cooling water flowing into the heat storage device 10 is:
It is insulated from the outside and kept warm. Heat storage device 1
The cooling water flowing out of the radiator 0 passes through the check valve 11, flows through the heat storage device outlet side passage C2, and enters the radiator inlet side passage A1
Flows into.

As described above, the cooling water heated by the engine 1 flows inside the heat storage device 10, and the inside of the heat storage device 10 is filled with the high-temperature cooling water. Then, after the engine 1 is stopped, the ECU 22 sets the electric water pump 1
If the operation of Step 2 is stopped, high-temperature cooling water can be stored in the heat storage device 10. The stored cooling water is prevented from lowering in temperature due to the heat retaining effect of the heat storage device 10.

The engine preheat control is started by starting up the ECU 22 when a trigger signal is input to the ECU 22.

The trigger signal serving as the control execution start condition is, for example, a door opening / closing signal of a driver's seat side transmitted by a door opening / closing sensor (not shown). Before the vehicle driver starts the engine 1 mounted on the vehicle, an operation of opening the door of the vehicle and getting on the vehicle naturally occurs. Therefore,
If it is detected that the vehicle door has been opened, the ECU 2
When the vehicle driver starts the engine 1, the engine 1 is kept warm when the engine 2 is started.

The ECU 22 circulates the high-temperature cooling water stored in the heat storage device 10 through the circulation passage C while the engine 1 is stopped, and controls the temperature of the engine 1.

FIG. 3 shows the state of the heat storage device 1 while the engine 1 is stopped.
FIG. 3 is a diagram showing a passage in which cooling water circulates and a flow direction thereof when heat is supplied from 0 to the engine 1. The direction of cooling water flow in the water jacket 23 when heat is supplied from the heat storage device 10 to the engine
Is opposite to the direction of cooling water flow when is operated. Here, during execution of the engine preheat control, the shut-off valve 31 is closed by the ECU 22.

The electric water pump 12 operates based on a signal from the ECU 22, and discharges cooling water at a predetermined pressure. The discharged cooling water flows through the heat storage device inlet side passage C1, passes through the check valve 11, and reaches the heat storage device 10. At this time, the cooling water flowing into the heat storage device 10 is cooling water whose temperature has been reduced while the engine 1 is stopped.

The cooling water stored in the heat storage device 10 flows out of the heat storage device 10 through the cooling water discharge pipe 10d. At this time, the cooling water flowing out of the heat storage device 10 is
High-temperature cooling water that flows into the heat storage device 10 during operation of the engine 1 and is kept warm by the heat storage device 10. The cooling water flowing out of the heat storage device 10 passes through the check valve 11, flows through the heat storage device outlet side passage C2, and flows into the cylinder head 1a. Here, while the engine 1 is stopped, E
Since the shutoff valve 31 is closed by a signal from the CU 22, the coolant does not circulate through the heater core 13.
Further, when the cooling water temperature is higher than the valve opening temperature of the thermostat 8, there is no need to supply heat from the heat storage device 10 to the engine 1, so that engine preheating control is not performed. That is, the circulation of the cooling water while the engine 1 is stopped is performed only when the thermostat 8 is closed. Therefore, the temperature of the cooling water does not decrease due to the heat exchange performed by circulating the cooling water through the heater core 13 and the radiator 9 during the engine preheating control.

The cooling water flowing into the cylinder head 1a is
The water jacket 23 is distributed. In the water jacket 23, heat exchange is performed between the cylinder head 1a and the cooling water. Part of the heat of the cooling water is transmitted inside the cylinder head 1a and the cylinder block 1b, and the temperature of the entire engine 1 rises. In addition, the temperature of the cooling water that has lost the heat decreases accordingly.

Thus, the water jacket 23
The cooling water whose temperature has been lowered by the transfer of the heat flows out from the cylinder block 1b and reaches the electric water pump 12 through the heat storage device inlet side passage C1.

As described above, the ECU 22 operates the electric water pump 12 prior to starting the engine 1 to increase the temperature of the cylinder head 1a (engine preheat control).

The heater 32 heats the cooling water when the temperature of the cooling water stored in the heat storage device 10 decreases. The heater 32 has a PTC thermistor (Positive Temperature) formed by adding an additive to barium titanate.
Coefficient Thermistor). The PTC thermistor is a heat-sensitive resistance element having a property that the resistance value rapidly rises when a predetermined temperature (Curie point) is reached. An element that generates heat by applying a voltage has a large resistance when it reaches the Curie point, so that it becomes difficult for current to flow, and the temperature decreases.
Then, when the temperature decreases, the resistance is reduced, so that the current easily flows and the temperature increases. in this way,
The PTC thermistor can perform self-temperature control that stabilizes at a substantially constant temperature without externally controlling the temperature.

When such a heater 32 is provided, the temperature of the cooling water circulated while the engine 1 is stopped and the temperature of which has decreased can be increased again, so that the temperature increasing function of the heat storage device 10 is maintained for a long time. It becomes possible. In the present embodiment, instead of constantly supplying power to the heater 32, C
The energization control is performed by the PU 351.

By the way, in the system applied in the present embodiment, that is, the system in which the heat exchange between the two members 1 and 10 is performed by the cooling water circulating between the engine 1 and the heat storage device 10,
Cooling water (hot water) stored in the heat storage device 10 is supplied to the engine 1, while cooling water in the engine 1 flows into the heat storage device 10. Therefore, while the temperature of the cooling water in the engine 1 gradually increases, the temperature of the cooling water in the heat storage device 10 gradually decreases. If the start of the engine 1 is postponed for some reason, the temperature of the heated engine 1 decreases and it is necessary to raise the temperature again. At this time, the temperature of the cooling water in the heat storage device 10 decreases. To achieve a sufficient effect. Here, the heat storage device 1
When the cooling water whose temperature in 0 is lowered is heated, it is possible to circulate hot water to the engine 1 again to supply heat, but heating of the cooling water requires power supply from the battery 30. . The battery 30 supplies electric power to a starter motor (not shown) and the like when the engine 1 is started, and if even the necessary electric power is used for heating the cooling water at this time, the startability of the engine 1 is reduced. May worsen.

Therefore, in the present embodiment, the cooling water heating time is determined based on the operation time of the engine 1. Here, there is a correlation between the operation time of the engine 1 and the amount of electricity charged in the battery 30.
Since there is a correlation between the power consumption of the heater 32 and the energizing time of the heater 32, the heater 3
It is possible to calculate the time during which power can be supplied to No. 2. As described above, in the present embodiment, since the cooling water is heated in consideration of the amount of electricity charged in the battery 30, the startability is not deteriorated, and the so-called battery exhaustion can be prevented. .

Next, a control flow when such cooling water heating control is performed will be described.

FIGS. 4 and 5 are flowcharts showing the flow of cooling water heating control. In this cooling water heating control, the cooling water temperature in the engine 1 is set to a predetermined temperature (for example, 80
° C. Hereinafter, it is referred to as a “retention target temperature”. ) When it falls below, the ECU 22 is started and started.

Here, when the ECU 22 is started, first, the CP
U351 resets the value of the counter n indicating the number of energizations of the heater 32 to 0.

In step S101, the amount of usable electricity remaining in the battery 30 after the previous cooling water heating control ends is calculated. Here, the available electric energy Ab charged to the battery before the previous execution of the cooling water heating control.
The difference between at0 and the amount of electricity Aex consumed by the heater 32 in the previous cooling water heating control is defined as a consumable additional amount of electricity Abat1 from the previous time.

The amount of electricity Abat0 charged to the battery before the previous execution of the cooling water heating control is obtained during the previous execution of the engine preheat control, and is stored in the backup RAM.
354. The amount of electricity Aex consumed by the heater 32 in the previous cooling water heating control is
Can be determined by multiplying this value by the measured energizing time of the heater 32 beforehand. The amount of electricity consumed each time the heater 32 is energized in the previous cooling water temperature increase control is added to the backup RAM 354 and becomes the amount of electricity Aex.

In step S102, it is determined whether the engine 1 has been started after the previous cooling water heating control. If it is determined that the engine 1 has been started, step S1
Go to 04. On the other hand, if a negative determination is made in step S102, the process proceeds to step S103.

In step S103, the previous engine 1
Of electricity Abat charged in the battery 30 during the operation of
Is set to 0. Here, since the engine 1 has not been operated after the previous cooling water heating control, no power is generated by the alternator, so that the amount of electricity charged in the battery 30 does not increase. The CPU 351 sets the Ab
At = 0 is stored in the RAM 353, and step S105 is performed.
Proceed to.

In step S104, the previous engine 1
Of electricity Abat charged in the battery 30 during the operation of
Is calculated.

FIG. 6 is a diagram showing the relationship between the charging time (the operating time of the engine 1) and the amount of electricity charged in the battery 30. If this map is stored in the ROM 352 in advance, the current charge amount Abat can be obtained from the operation time of the engine 1. This charge Abat
Is preferably determined in consideration of the amount of electricity consumed by the starter motor when the engine 1 is started. Specifically, the difference between the amount of electricity newly charged in the battery 30 obtained from FIG. 6 and the amount of electricity consumed by the starter motor at the time of starting the engine 1 is defined as the charged amount Abat. The operating time of the engine 1 uses the one stored in the backup RAM 354. The CPU 351 calculates the calculated charge amount A
The value of bat is stored in the RAM 353, and the process proceeds to step S10.
Go to 5.

In step S105, the amount of electricity Abat0 that can be consumed by the heater 32 when the temperature of the cooling water is raised this time is calculated. The amount of electricity Abat0 that can be consumed by the heater 32 when the temperature of the cooling water is increased this time is calculated by adding the amount of electricity Abat1 calculated in step S101 to step S103 or step S104.
It is obtained by adding the electric quantity Abat calculated in. The obtained electric quantity Abat0 is the backup RA
It is stored in M354.

In step S106, it is determined whether or not the temperature in the heat storage device 10 is higher than a target temperature for keeping heat (for example, 80 ° C.). If a positive determination is made, step S10
Then, at this time, it is not necessary to raise the temperature of the cooling water in the heat storage device 10. On the other hand, when a negative determination is made, the process proceeds to step S108, and the temperature rise control of the cooling water is performed.

In step S107, the initial water temperature Tw left unattended
0 is the cooling water temperature in the heat storage device 10 when the engine 1 is stopped.

In step S108, the power consumption Ab required by the heater 32 to heat the cooling water in the heat storage device 10 to a temperature at which the temperature of the heater 32 can be raised (for example, 90 ° C.)
At 90 is calculated. This value is obtained by storing in the ROM 352 the amount of cooling water (volume) in the heat storage device 10 and the amount of electricity consumed per unit time of the heater 32 in advance.
It can be determined by calculating the amount of energy required to raise the temperature of the cooling water within 0 from the current temperature to the temperature at which the heater 32 can be heated (for example, 90 ° C.).

In step S109, it is determined whether or not the amount of electricity required by the heater 32 has been charged in the battery 30. Here, the amount of electricity Abat that can be consumed by the heater 32 at the time of the current rise of the cooling water obtained in step S105.
Abat, which is a deviation between 0 and the amount of electricity consumed Abat90 required for the cooling water temperature in the heat storage device 10 to reach the temperature at which the temperature can be raised (for example, 90 ° C.) determined in step S108.
The determination is made based on whether or not r is greater than 0. When an affirmative determination is made, the process proceeds to step S112, and when a negative determination is made, the process proceeds to step S110.

In step S110, step S109
Time heater 3 corresponding to the amount of electricity Abatr calculated in
2 is energized. The energization time is determined by the amount of power consumption of the heater 32 per unit time.

In step S111, the current engine 1
During the stop, the temperature rise of the cooling water due to the energization of the heater 32 is prohibited, and the routine ends.

In step S112, step S108
The amount of power consumed by the heater 32 required to raise the temperature of the cooling water in the heat storage device 10 from the current temperature to the temperature at which the heater 32 can be heated (for example, 90 ° C.) is calculated. Energize. Even if the heater 32 consumes an amount of electricity equivalent to the amount of electricity Abat90, the battery 30 is charged with the amount of electricity Abat0 greater than that, so that the battery does not run out.

In step S113, the initial water temperature Tw for standing
0 is 90 ° C.

In step S114, the electric energy Abat0 calculated in step S109 is added to the consumable electric energy Abat0.
Substitute the value of atr. After the heater 32 is energized, the amount of electricity that can be used by the heater 32 remaining in the battery 30 decreases by the amount consumed in step S112. The value of the new electricity amount Abat0 is stored in the backup RAM 354.

In step S115, step S107
Alternatively, the standing initial water temperature Tw calculated in step S113
From Time 0 and the outside air temperature Ta0 when the engine 1 is stopped, a time Time1 at which the temperature of the cooling water in the heat storage device 10 falls to the target heat retention temperature Twh (for example, 80 ° C.) is calculated. For the calculation of the time Time1, the relationship between the initial water temperature Tw0, the outside air temperature Ta0 when the engine 1 is stopped, and the time Time1 may be mapped in advance.

In step S116, the amount of electricity Abat10 required to raise the temperature of the cooling water in the heat storage device 10 by a predetermined temperature (for example, 10 ° C.) is calculated. At this time, the temperature of the cooling water is the target water temperature Twh (for example, 80 ° C.), and the amount of electricity Abat required to raise the temperature of the cooling water again to a temperature at which the heater 32 can be heated (for example, 90 ° C.)
10 is calculated.

In step S117, it is determined whether or not the amount of electricity required by the heater 32 is sufficiently remaining in the battery 30. Here, the amount of electricity Abat that can be consumed by the heater 32 at the time of the current temperature rise of the cooling water obtained in step S114.
The determination is made based on whether or not the deviation between 0 and the amount of electricity Abat10 required to raise the temperature of the cooling water in the heat storage device 10 obtained in step S116 by a predetermined temperature (for example, 10 ° C.) is larger than 0. When an affirmative determination is made, the process proceeds to step S121, and when a negative determination is made, the process proceeds to step S118.

In step S118, the energization time Tt0 of the heater 32 corresponding to the amount of electricity Abat0 that can be consumed by the heater 32 when the temperature of the cooling water is raised this time is calculated.

In step S119, the previous heater 32
Time Time calculated in step S115 from the end of energization
Time T calculated in step S118 when 1 has elapsed
Power is supplied to the heater 32 for t0.

In step S120, during the subsequent stop of the engine 1, the temperature rise of the cooling water due to the energization of the heater 32 is prohibited, and this routine ends.

In step S121, step S116
The energization time Tt10 of the heater 32 corresponding to the amount of electricity Abat10 calculated in the above is calculated.

In step S122, the previous heater 32
Time Time calculated in step S115 from the end of energization
Time T calculated in step S121 when 1 has elapsed
Power is supplied to the heater 32 for t10.

In step S123, the electric quantity Abat0
The deviation between the electric quantity Abat10 and the electric quantity Abat
Set to 0. At this time, the available electricity amount of the battery 30 is the newly calculated electricity amount Abat0. The value of the new electricity amount Abat0 is stored in the backup RAM 354.

In step S124, 1 is added to the value of the counter n.

In the step S125, it is determined whether or not the value of the counter n is 2. When the value of the counter n is 2, it means that the heater 32 is energized once in step S112 and then energized twice in step S122. That is, the temperature of the cooling water is increased three times in total.
Is not started, it is considered that the start of the engine 1 is postponed for some reason. Therefore, when an affirmative determination is made, the routine is terminated without energizing the heater 32 any more, and the amount of electricity that can be energized to the heater 32 again is stored in the battery when the temperature of the cooling water needs to be raised next time. I will keep it. On the other hand, when a negative determination is made, the process returns to step S106 to raise the temperature of the cooling water again.

FIG. 7 is a diagram showing the transition of the temperature of the cooling water in the heat storage device 10 when this routine is executed. In this manner, the temperature of the cooling water in the heat storage device 10 is repeatedly increased based on the amount of electricity stored in the battery until the engine 1 is started.

Here, in the conventional engine, a decrease in heat retention due to aging or the like in the heat storage device has not been considered. After the engine preheat control is completed, a considerable period may elapse before the driver actually starts the engine.Even if the engine preheat control is completed, the engine will maintain the temperature after the engine preheat control is completed. It is desirable to keep it for as long as possible. Further, when the operation of the engine for a relatively short period is intermittently repeated, or when the engine has not been started for a long time since the end of the previous operation of the engine, a sufficient amount of heat is stored in the heat storage device. Not always. In such a case, it is necessary to heat the cooling water with a large-capacity heater. However, a large current may flow for a long period of time during the heat retention unless the heat retention is reduced, which may cause so-called battery exhaustion. In order to solve such a problem, it is necessary to provide an ammeter or the like and monitor the charge amount of the battery.

In this regard, the heat storage device 10 according to the present embodiment
According to the engine 1 provided with, the heating of the cooling water by the heater 32 is intermittently performed while taking into account the operation time of the engine 1, thereby preventing the battery from running out without using a measuring device such as an ammeter. be able to.

As described above, according to the present embodiment, heater 32 can heat the cooling water within the range of the amount of electricity stored in battery 30.

[0107]

According to the present invention, there is provided an internal combustion engine provided with a heat storage device, comprising a heating means for heating a heat medium of the heat storage device using energy stored in the heat storage means. It is possible to heat the heat medium of the heat storage device to the maximum while securing the necessary minimum energy to be kept.

Therefore, according to the internal combustion engine provided with the heat storage device of the present invention, it is possible to store the maximum heat without affecting the startability of the internal combustion engine.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing both an engine to which a heat storage device of an internal combustion engine according to an embodiment of the present invention is applied and a cooling water passage through which cooling water circulates.

FIG. 2 is a block diagram showing an internal configuration of an ECU.

FIG. 3 is a diagram showing a passage in which cooling water circulates and a flow direction thereof when heat is supplied from the heat storage device to the engine while the engine is stopped.

FIG. 4 is a first half of a flowchart illustrating a flow of cooling water heating control according to the embodiment of the present invention.

FIG. 5 is a second half of a flowchart illustrating a flow of cooling water heating control according to the embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between a charging time (engine operating time) and an amount of electricity charged to a battery.

FIG. 7 is a time chart showing transition of the temperature of the cooling water in the heat storage device when the cooling water heating control is executed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine 1a ... Cylinder head 1b ... Cylinder block 1c ... Oil pan 2 ... Cylinder 6 ... Water pump 8 ... Thermostat 9 ... Radiator 10 ··· Thermal storage device 10a ··· Outer container 10b ··· Inner container 10c ··· Cooling water injection pipe 10d ··· Cooling water discharge pipe 11 ··· Check valve 12 ··· Electric water pump 13 ··· Heater core 22 ... ECU 23 ... Water jacket 27 ... Crank position sensor 28 ... Cooling water temperature sensor in heat storage device 29 ... Cooling water temperature sensor in engine 30 ... Battery 31 ... Shutoff valve 32 ... heater A ... circulation passage A1 ... radiator inlet side passage A2 ... radiator outlet side passage B ... circulation passage B1 ... heat Takoa inlet side passage B2 ... heater core outlet side passage C ... circulation passage C1 ... heat storage device inlet side passage C2 ... heat storage device outlet side passage

Claims (3)

[Claims] 1. Heat storage means for storing heat of a heat medium, heat supply means for supplying the heat medium stored in the heat storage means to an internal combustion engine, and power storage means for storing energy generated during operation of the internal combustion engine A heating unit supplied with energy from the power storage unit to heat the heat medium stored in the heat storage unit; and a consumption limit calculation for calculating an amount of energy that can be consumed by the heating unit based on an operation time of the internal combustion engine. Means, wherein the heating means heats the heat medium within the range of the consumable energy amount calculated by the consumption limit calculating means. 2. The consumption limit calculating means includes: an energy amount stored in the power storage means before the last operation of the internal combustion engine; and an engine operation time when the internal combustion engine was last operated. The internal combustion engine provided with a heat storage device according to claim 1, wherein the amount of energy that can be consumed by the heating means is calculated based on the following formula. 3. A heat medium temperature measuring means for measuring a temperature of a heat medium stored in the heat storage means, wherein the heating means measures a temperature of the heat medium temperature measuring means at or below a predetermined temperature while the internal combustion engine is stopped. The heating medium is heated for a predetermined period of time every time the power consumption of the internal combustion engine is stopped, and the heating is stopped when the total energy consumption during the stoppage of the internal combustion engine becomes larger than the calculation result of the consumption limit calculation unit. An internal combustion engine equipped with a heat storage device.