JP3376891B2 - Internal combustion engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine which utilizes a part of cooling water for cooling an internal combustion engine body as a heat medium for a vehicle interior heater.

[0002]

2. Description of the Related Art In a cooling water circulating device for an internal combustion engine, the heat released from the body of the internal combustion engine is absorbed by the cooling water, and a part of the absorbed heat is used as a heat source for a passenger compartment heater that warms the passenger compartment. There is.

For this purpose, the internal cooling water passage formed in the internal body of the internal combustion engine flows through a so-called water jacket, during which the cooling water that has absorbed heat from the internal combustion engine body and is warmed is heated to the internal combustion engine body and the vehicle compartment heater. The cooling water circulation circuit on the heater side that circulates and circulates the fluid is sent from the internal combustion engine body to the vehicle interior heater.

However, immediately after the internal combustion engine is started, the cooling water is not yet sufficiently warm, so that the effect of the vehicle interior heater is not good. Therefore, for example, JP-A-59-119010
The publication discloses a technique in which a flow control valve is provided so that the amount of cooling water reaching the vehicle interior heater can be adjusted according to the cooling water temperature. According to this, when the cooling water temperature is low, the cooling water temperature is raised by narrowing the flow rate of the cooling water and reducing the flow rate, so that even when the internal combustion engine is started, the rising speed of the vehicle interior heater can be increased. It can be hastened.

[0005]

However, if the internal combustion engine generates a small amount of heat when the flow control valve is opened, the amount of heat radiated from the vehicle interior heater is greater than the amount of heat received from the internal combustion engine. As a result, the temperature of the cooling water drops immediately, which causes the flow control valve to close again, resulting in hunting operation. When the flow control valve performs the hunting operation in this way, the cooling water temperature also hunts, but the cooling water can be maintained at the set water temperature on average.

However, since the flow control valve is hunting in a state that it is almost fully closed, the amount of cooling water flowing to the vehicle interior heater is small and a sufficient amount of heat cannot be supplied to the vehicle interior heater. The effect of the heater for the passenger compartment was insufficient.

The present invention has been invented in view of the above circumstances, and it is a technical object of the present invention to improve the effectiveness of a heater for a vehicle compartment when the internal combustion engine is started quickly.

[0008]

In order to achieve the above object, an internal combustion engine of the present invention has an internal combustion engine body having a cooling water internal passage through which cooling water for cooling a cylinder flows, and an internal cylinder of the internal combustion engine body. Fuel injection means for injecting fuel into the internal combustion engine, an exhaust passage for exhausting exhaust gas generated by burning the fuel in the cylinder of the internal combustion engine body, and a vehicle interior heater using a part of the cooling water as a heat medium And a heater-side cooling water circulation circuit for circulating the cooling water between a cooling water internal passage of the internal combustion engine body and the vehicle interior heater, and a component of the heater-side cooling water circulation circuit, the internal combustion engine body Flow control for reducing the amount of cooling water to the heater for vehicle compartment from the cooling water passage to the heater for vehicle compartment to the heater passage for cooling water when the temperature of the cooling water is below a first predetermined temperature Valve and In obtain internal combustion engine was configured as follows.

That is, the exhaust passage is provided with an exhaust throttle valve that throttles the exhaust passage when the cooling water temperature is equal to or lower than a second predetermined temperature that is set higher than the first predetermined temperature .
A fuel increasing means is provided for increasing the fuel injected from the fuel injection means when the exhaust passage is throttled by the exhaust throttle valve.

Here, the flow rate control valve is a thermostat or thermostat type flow rate control valve which is closed when the temperature of the cooling water is equal to or lower than the first predetermined temperature and opens when the temperature exceeds the first predetermined temperature. When the cooling water is warm enough to open the flow control valve, the cooling water circulates in the heater-side cooling water circulation circuit, and when the cooling water is cold enough to close the flow control valve, the heater-side cooling water circulation No cooling water is circulated in the circuit. However, this flow control valve does not have a structure in which cooling water does not flow at all even when it is closed, and it has a structure in which the temperature of the cooling water can be understood, that is, cooling water flows slightly for temperature sensing. preferable.

Second exhaust passage is throttled by the exhaust throttle valve
The predetermined temperature is set to be higher than the first predetermined temperature at which the flow control valve reduces the amount of the cooling water flowing to the vehicle interior heater.

Therefore, when the temperature of the cooling water is equal to or lower than the first predetermined temperature, the exhaust throttle valve throttles the exhaust passage, and the flow control valve reduces the amount of the cooling water flowing to the passenger compartment heater.

Then, at that time, the fuel increasing means increases the amount of fuel injected into the cylinder in response to the increase in the load of the internal combustion engine due to the narrowed exhaust passage, so that the cooling water from the internal combustion engine main body is increased. The amount of heat received is increased.

Further, at this time, since no cooling water flows in the heater side cooling water circulation circuit or very little cooling water flows, the heat radiation from the heater is extremely small. Therefore,
Since the amount of heat released from the cooling water is small relative to the amount of heat received by the cooling water, the temperature of the cooling water can be raised early. Also,
Since no heat is radiated from the vehicle interior heater using cooling water as a heat medium, the warm-up time of the internal combustion engine is also shortened. Further, it is possible to prevent the cold air from being blown out into the room for a long time when the cooling water has a low temperature.

Further, during this period, the flow control valve is throttled to reduce the amount of the cooling water flowing through the heater side cooling water circulation circuit. Therefore, the throttle of the exhaust passage by the exhaust throttle valve is not greatly throttled so much and the heat receiving amount of the cooling water is received. Can be increased, the deterioration of fuel consumption can be suppressed, and the deterioration of emissions such as smoke can be suppressed.

When the temperature of the cooling water exceeds the first predetermined temperature, the flow control valve opens and a large amount of cooling water circulates in the heater side cooling water circulation circuit. If the temperature of the cooling water exceeds the first predetermined temperature but does not exceed the second predetermined temperature, the exhaust passage is held in a throttled state by the exhaust throttle valve, and fuel is also increased and injected. Therefore, the amount of heat received from the internal combustion engine body of the cooling water remains large.
Therefore, even if a large amount of cooling water circulates in the heater side cooling water circulation circuit and the amount of heat radiation from the vehicle interior heater increases, the flow control valve does not cause hunting and is kept in a stable open state. . In addition, since the amount of heat received by the cooling water is large, it is possible to increase the temperature of the cooling water at equilibrium that balances the amount of heat released by the heater for the passenger compartment, and therefore the amount of heat released by the heater for the passenger compartment can be increased quickly. , The effectiveness of the passenger compartment heater is improved.

When the temperature of the cooling water exceeds the second predetermined temperature, the exhaust throttle valve opens to reduce the load on the internal combustion engine, and the amount of fuel supplied to the main body of the internal combustion engine becomes the amount supplied during normal operation. , Although the amount of cooling water received from the internal combustion engine main body decreases, the temperature of the cooling water has already risen sufficiently before that, so it is possible to cover the amount of heat radiation from the vehicle interior heater. The effectiveness of the heater can be stably maintained.

[0018]

DETAILED DESCRIPTION OF THE INVENTION

<Overall Configuration of Device> An embodiment of the present invention will be described below with reference to the accompanying drawings.

First, referring to FIG. 1, an overall schematic structure of a diesel engine 1 as an internal combustion engine will be described. Engine body (internal combustion engine body) 3 of the diesel engine 1
Is a cylinder block (not shown) provided with a plurality of cylinders 50, 50, ... (4 cylinders in the figure), and a cylinder head 5 installed above the cylinder block.
Have two.

An intake manifold 54 and an exhaust manifold 56 are connected to the cylinder head 52, and intake air from the intake manifold 54 is supplied to each cylinder 50 via an intake valve (not shown) provided corresponding to each cylinder 50. Gas can be supplied to a combustion chamber (not shown), and gas in the combustion chamber of each cylinder 50 can be exhausted to the exhaust manifold 56 via an exhaust valve (not shown) provided corresponding to each cylinder 50.

In addition, injectors 58, 58, ... Are arranged in the cylinder head 52 so as to face the combustion chamber of each cylinder 50. From each injector 58, the fuel supplied by the injection pump 60 is injected into the combustion chamber of each cylinder 50. Therefore, the injector 58 and the injection pump 60
Is a fuel injection means.

A rotation speed sensor 62 for detecting the engine rotation speed is attached to the injection pump 60. The injectors 58 and the injection pumps 60 are electrically connected to the ECU 64.

An intake pipe 66 as an intake passage is connected to the intake manifold 54, and an exhaust pipe 68 as an exhaust passage is connected to the exhaust manifold 56.

Further, the diesel engine 1 is equipped with a turbocharger 70. Turbocharger 70
Is provided with a turbine 72 and a compressor 74 coaxial with the turbine 72.
By rotating 2 the pressurized air is forced into each cylinder 50.

An intercooler 76 for cooling the compression heat of the intake air pressurized by the turbocharger 70 is arranged between the intake pipe 66 and the intake manifold 54.

The exhaust pipe 68 has, for example, an exhaust throttle VSV.
An exhaust throttle valve 80 connected to and driven by a pressure control valve 78 such as a (vacuum switching valve) is attached. The exhaust throttle valve 80 includes a valve body 80a located inside the exhaust pipe 68, and an actuator 80b as a drive unit that drives the valve body 80a. Also, this exhaust throttle valve 8
Reference numeral 0 is a normally open type valve having a diaphragm portion (not shown) in the actuator 80b.

The pressure control valve 78 is connected to a vacuum tank (not shown) and the atmosphere. A pressure switching signal from the ECU 64 switches whether the diaphragm portion of the exhaust throttle valve 80 is connected to the vacuum tank or to the atmosphere. The pressure control valve 78 controls ON / OFF of whether the exhaust throttle valve 80 is open or closed. That is, when the pressure control valve 78 applies atmospheric pressure to the diaphragm portion of the exhaust throttle valve 80, the exhaust throttle valve is turned off.
When the pressure control valve 78 applies a negative pressure to the diaphragm portion, the exhaust throttle valve 80 is turned on and closed.

Here, the ECU 64 outputs a switching signal of the pressure control valve 78 based on the water temperature of the cooling water of the engine 1 detected by a water temperature sensor 36 described later, and controls the exhaust throttle valve 80 to turn on / off. That is, the temperature of the cooling water is the second
When the temperature is equal to or lower than the predetermined temperature T ₂ , the exhaust throttle valve 80 is turned on and closed, and when the temperature exceeds the _second predetermined temperature T ₂ , the exhaust throttle valve 80 is turned off and opened.

The exhaust throttle valve 80 does not completely close when closed, but only throttles the passage.
For the sake of convenience, this specification calls it a closed valve. On the other hand, the portion located downstream of the exhaust manifold 56 and the portion located upstream of the intake manifold 54 are connected by an exhaust gas recirculation passage 82.

The exhaust gas recirculation passage 82 is the exhaust gas recirculation passage 8
2 is a passage for returning a part of the exhaust gas from the exhaust manifold 56 to the intake manifold 54, as shown by the thick arrow in FIG. 2. The exhaust manifold 56 and the intake manifold 54 are bypassed with respect to the cylinder head 52. Connecting.

The exhaust gas recirculation passage 82 is substantially L-shaped when seen in a plan view, and the bending point 82a thereof has an EG.
An R valve 84 is provided. The EGR valve 84 is a variably controllable valve that limits the amount of exhaust gas flowing from the exhaust manifold 56 to the intake manifold 54 via the exhaust gas recirculation passage 82 at least when the exhaust throttle valve 80 is closed. 84 is an EG not shown
The opening degree of the engine 1 is controlled by the ECU 64 based on the operating state of the engine 1 via the R duty VSV.

An intake air temperature sensor 86 is provided at an appropriate position of the vehicle (not shown) to which the diesel engine 1 is attached, in contact with the atmosphere, and the depression amount (accelerator opening) of the accelerator pedal (not shown) is converted into an electrical signal. An accelerator sensor 88 to be changed is provided near an accelerator pedal (not shown). The intake air temperature sensor 86 detects the outside air temperature. Further, the transmission (not shown) is provided with a speed sensor 90. The rotation speed sensor 62, the intake air temperature sensor 86, the accelerator sensor 88, and the speed sensor 90 are electrically connected to the ECU 64.

The parameters output by the water temperature sensor 36, the rotation speed sensor 62, the intake air temperature sensor 86, the accelerator sensor 88 and the speed sensor 90 are set to E.
The arithmetic processing of the CU 64 drives the pressure control valve 78 and the EGR duty VSV (not shown), and as a result, the exhaust throttle valve 80 and the EGR valve 84 are appropriately controlled according to the operating state of the diesel engine 1. It

Further, the injector 58, under the control of the ECU 64, injects and supplies an appropriate amount of fuel to the combustion chamber of each cylinder 50 at an appropriate time by the injection pump 60 according to the output value of each sensor. It is like this.

When the exhaust throttle valve 80 is closed, the ECU 64 increases the engine load by increasing the amount of fuel injected into the cylinder 50 in response to the increase in engine load caused by the throttle of the exhaust pipe 68. The injector 58 is controlled so as to increase the amount of the exhaust throttle valve 80 when the exhaust throttle valve 80 is opened. Therefore, it can be said that the ECU 64 is a fuel increasing means.

On the other hand, cooling water flows inside the cylinder head 52 and a cylinder block (not shown) in order to absorb combustion heat in each cylinder 50 and maintain the diesel engine 1 at an appropriate temperature. The cooling water circuit will be described with reference to the cooling water flow chart of FIG.

A water jacket (cooling water internal passage) 12 for passing cooling water is formed inside the engine body 3, and a water temperature sensor 36 is provided in the water jacket 12.
The water temperature sensor 36 is electrically connected to the ECU 64.

The engine 1 has a radiator 5 on the left side of the engine body 3 and a vehicle interior heater core 7 on the right side.
And an oil cooler 9 is arranged on the lower side, and these 5, 7, 9 are connected by a cooling water external passage 11 with the engine body 3 as the center. The cooling water external passage 11 includes the constituent passages 13, 14, 19, 21, which will be described in order below.
It consists of 30, 32.

When the radiator 5 absorbs the heat emitted from the engine body 3 while the cooling water passes through the water jacket 12, the radiator 5 releases the heat to the atmosphere. The vehicle interior heater core 7 uses a part of the cooling water that has absorbed the heat generated by the engine body 3 as a heat medium, and emits warm air into the vehicle interior.

The oil cooler 9 cools the lubricating oil contained in the engine 1 using cooling water as a cooling medium. As described above, the cooling water external passage 11 includes the engine body 3, the radiator 5, the passenger compartment heater core 7, and the oil cooler 9.
And communicates cooling water to them.

The communication passage 13, which is a part of the cooling water external passage 11, is located above the engine body 3 in FIG. Then, in the water jacket 12, the heater side opening 12a opening to the heater core 7 side and the radiator inlet 5a provided at the upper portion of the radiator 5 are connected, and the cooling water flows from the engine body 3 to the radiator 5. 13 is called a connecting passage 13 to the radiator.

The radiator connecting passage 13 is a passage through which cooling water that has been absorbed from the engine body 3 and has heat while passing through the water jacket 12 is passed. The communication passage 14, which is another part of the cooling water external passage 11, is located below the radiator 5 and the engine body 3 in FIG. 2. The communication passage 14 is connected to the radiator outlet 5b.
And the radiator side opening 12b that opens to the radiator 5 side of the engine body 3 are connected to each other, and cooling water is supplied to the radiator 5
Side to the engine body 3 side. Therefore, the communication passage 14
This is called the connecting passage 14 for the engine body. The engine main body connecting passage 14 is provided with a flow passage switching valve (cooling water flow passage switching means) 15 and a water pump 17 in the middle thereof in order from the radiator 5 side.

The water pump 17 sends the cooling water to the entire cooling water passage 11. Further, between the flow path switching valve 15 and the radiator-side opening 12c located above the radiator jacket opening of the engine body 3 on the radiator 5 side, another one of the cooling water external passages 11 is provided. An L-shaped communication passage 19 is provided.

The communication passage 19 is a bypass passage provided for bypassing the radiator 5 and allowing the cooling water to flow when the temperature of the cooling water is not high enough to cool the cooling water through the radiator 5. Therefore, the communication passage 19 is hereinafter referred to as a radiator bypass passage 19.

The flow path switching valve 15 is a thermostat type switching valve, and when the temperature of the cooling water exceeds the third predetermined temperature T ₃ , the radiator bypass passage 19 side is closed and the radiator 5 side is opened to cool the cooling water. When the temperature of the cooling water is equal to or lower than the _third predetermined temperature T3, the radiator 5 side is closed and the radiator bypass passage 19 side is opened to allow the cooling water to pass through the radiator bypass passage 19.
The flow path of the cooling water is switched so that the cooling water flows.

The communication passage indicated by reference numeral 21 between the heater core 7 and the engine body 3 on the right side of FIG. 2 is also a part of the cooling water external passage 11, and extends from the heater side opening 12a of the water jacket 12 to the passenger compartment. Entrance 7a of heater core 7
It extends straight toward. This communication passage 21 is called a communication passage 21 to the heater core because cooling water flows from the engine body 3 toward the heater core 7.

A flow control valve 23 of thermostat type is disposed in the middle portion M of the communication passage 21 for the heater core. The flow path switching valve 15 is also the flow control valve 23.
However, since it is a well-known structure, description of the structure is omitted.

When the temperature of the cooling water exceeds the first predetermined temperature T ₁ , the flow control valve 23 opens to allow the cooling water to flow, and when the temperature of the cooling water is the first predetermined temperature T ₁ or lower. Shuts off the cooling water by closing the valve. Note that the flow control valve 23 does not mean that the cooling water does not flow at all even when it is closed, and even when the flow control valve 23 is closed, it slightly passes through a small hole for temperature sensing provided in a valve body (not shown) (for example, 0.5 per minute). Since it is designed to flow, the flow control valve 23
It can be said that when the cooling water temperature is equal to or lower than the _first predetermined temperature T ₁ , the amount of the cooling water flowing through the heater core going communication passage 21 is decreased.

The first predetermined temperature T of the flow control valve 23
₁ is set to a temperature lower than the second predetermined temperature T ₂ of the exhaust throttle valve 80 and lower than the third predetermined temperature T ₃ of the flow path switching valve 15.

The communication passage 14 for the engine body is also provided.
The heater core connecting passage 21 is communicated with an oil cooler cooling water communicating passage 30 including an oil cooler 9. The oil cooler cooling water communicating passage 30 also constitutes the cooling water external passage 11. Is part of.

The radiator side end 30a of the oil cooler cooling water communication passage 30 is connected to the engine main body connecting passage 14 at a downstream side portion of the water pump 17. In addition, the heater core side end 30b of the oil cooler cooling water communication passage 30 is provided in the heater core going communication passage 21.
Flow control valve 23 and communication passage 13 for the radiator
Are connected at a connection point C which is on the upstream side of the entrance 13a.

In this embodiment, the cooling water communication passage 30 for the oil cooler is shown as provided outside the engine body 3 as a part of the cooling water external passage 11, but the water is provided inside the engine body 3. It may be provided separately from the jacket 12.

Further, as another communication passage constituting the cooling water external passage 11, a communication passage 32 connecting the outlet 7b of the vehicle interior heater core 7 and the communication passage 14 for the engine body.
There is. The communication passage 32 is a passage for returning the cooling water that has entered the heater core 7 to the water pump 17. Also,
A connection point of the communication passage 32 with the communication passage 14 for the engine body is a portion between the flow passage switching valve 15 and the water pump 17.

The cooling water is supplied to the communication passages 13,
Radiator 5 by 14, 19, 21, 30, 32
Between the engine and the engine body 3, and the heater core 7 for the passenger compartment
And the engine body 3 can be circulated.

The cooling water circulating device A of the diesel engine 1 has the above-mentioned configuration. In this cooling water circulation device A, between the radiator 5 and the engine body 3, the cooling water discharged from the heater side opening 12a of the water jacket 12 enters the heater core connecting passage 21 and then immediately goes to the radiator. If it enters the communication passage 13 and then reaches the radiator 5, and if the flow passage switching valve 15 opens the radiator 5 side, the communication passage 1 to the engine body 1
Return to the water jacket 12 via 4. The path through which the cooling water circulates in this way is called a radiator-side cooling water circulation circuit E. If the flow path switching valve 15 closes the radiator 5 side and opens the radiator bypass passage 19 side, cooling water does not flow into the radiator 5.

Since the communication passage 14 for the engine body is also connected to the cooling water communication passage 30 for the oil cooler, when the cooling water is circulating in the radiator side cooling water circulation circuit E, the cooling water is the cooling water communication passage for the oil cooler. It can also flow to the passage 30. The cooling water introduced into the oil-cooler cooling water communication passage 30 is discharged at a portion of the heater core going communication passage 21 upstream of the flow rate control valve 23.

Between the passenger compartment heater core 7 and the engine body 3, the cooling water discharged from the heater side opening 12a of the water jacket 12 enters the heater core going communication passage 21 and then flows through the flow control valve 23. If it is open, it will pass therethrough to reach the passenger compartment heater core 7, and will reach the engine body connecting passage 14 via the connecting passage 32 connecting the heater core 7 and the engine body connecting passage 14 to this engine body. Return to the water jacket 12 via the connecting passage 14. The path through which the cooling water circulates in this way is called a heater-side cooling water circulation circuit F. Even when the cooling water circulates in the heater side cooling water circulation circuit F, the cooling water can flow into the oil cooler cooling water communication passage 30.

On the other hand, if the flow control valve 23 is closed, cooling water does not flow to the heater core 7. Then, as described above, the closing upper limit temperature of the flow control valve 23 (that is, the first predetermined temperature T ₁ ) is the temperature at which the flow path switching valve 15 closes the radiator 5 side (that is, the third predetermined temperature T _3). ), The flow path switching valve 15 always closes the radiator 5 side and opens the radiator bypass passage 19 side when the flow rate control valve 23 is closed. Therefore, at this time, the cooling water does not flow to the radiator 5 and the heater core 7, and the cooling water flowing out from the radiator side opening 12c of the water jacket 12 passes through the radiator bypass passage 19 and the engine main body connecting passage 14 to the water jacket. I will return to 12. A path in which the cooling water bypasses the radiator 5 and circulates in this way is called a radiator bypass circuit G. Although the cooling water does not flow to the heater core 7, as described above, a very small amount of cooling water for temperature sensing flows to the heater core 7 and circulates in the heater side cooling water circulation circuit F.

Even when the cooling water circulates in the radiator bypass circuit G, the cooling water can flow to the oil-cooler cooling water communication passage 30.

<Operation and Effect of Embodiment> Next, the operation and effect of this diesel engine will be described. In this embodiment, the first predetermined temperature T related to the flow control valve 23
The magnitude relationship between ₁ and the second predetermined temperature T ₂ related to the exhaust throttle valve 80 and the third predetermined temperature T ₃ related to the flow path switching valve 15 is T ₁ <T ₂ <T ₃ . However, in the present invention, T ₁ <
It holds even if T ₃ <T ₂ .

When the temperature of the cooling water is equal to or lower than the _first predetermined temperature T ₁ when the engine 1 is started, the flow control valve 23
Is closed, the exhaust throttle valve 80 is closed, and the flow path switching valve 15 closes the radiator 5 side and opens the radiator bypass passage 19 side.

Since the load on the engine 1 increases when the exhaust throttle valve 80 is throttled, the ECU 64 increases the fuel amount by the amount corresponding to the increase in the load as compared with when the exhaust throttle valve 80 is open. The injector 58 is controlled to inject fuel into the cylinder 50. Due to this increase in the amount of fuel, the combustion heat in the engine body 3 is exhausted.
The amount of heat that the cooling water receives from the diesel engine 1 (hereinafter, simply referred to as “heat receiving amount” unless otherwise specified is the amount of heat that the cooling water receives from the diesel engine 1) increases.

On the other hand, the cooling water at this time is the radiator 5
Does not flow into the radiator bypass circuit G through the radiator bypass passage 19 and only a small amount of cooling water for temperature sensing flows into the heater core 7.
The heat radiation amount in the heater core 7 is extremely small.

That is, since the amount of heat radiated from the cooling water is smaller than the amount of heat received by the cooling water, the cooling water circulating in the radiator bypass circuit G can be quickly heated and
Since the temperature of the cylinder bore wall can be quickly raised, the engine 1
It is possible to significantly reduce the warm-up time until the engine is operated stably.

Further, since only a small amount of cooling water for temperature sensing flows through the heater core 7, cold air is blown into the vehicle interior for a long time when the temperature of the cooling water from which the heater core 7 feels cold is low. Can be prevented.

Further, during this time, the flow control valve 23 is throttled to reduce the amount of the cooling water flowing through the heater side cooling water circulation circuit F. Therefore, the throttle of the exhaust passage by the exhaust throttle valve 80 should not be greatly throttled. The amount of heat received can be increased, the deterioration of fuel consumption can be suppressed, and the deterioration of emissions such as smoke can be suppressed.

Further, the diesel engine 1 is warmed up early, so that the exhaust gas can be recirculated early. Further, since the cooling water also flows in the oil cooler cooling water communication passage 30, the temperature of the lubricating oil of the engine 1 can be raised early.

Next, when the temperature of the cooling water rises and exceeds the first predetermined temperature T ₁ , the flow rate control valve 23 opens, and the engine main body 3 and the heater core 7 are connected via the heater side cooling water circulation circuit F. However, the cooling water will be circulated. Even if the temperature of the cooling water exceeds the first predetermined temperature T ₁ , the second
Since the exhaust passage is held in a throttled state by the exhaust throttle valve 80 and the amount of fuel is also increased and injected while the predetermined temperature T ₂ of the above is not exceeded, the heat receiving amount of the cooling water remains large. .

Therefore, even if a large amount of cooling water circulates in the heater side cooling water circulation circuit F and the amount of heat radiation from the heater core 7 increases, the flow rate control valve 23 does not hunt and is stable. Held in a state. Further, since the amount of heat received by the cooling water is large, it is possible to increase the temperature of the cooling water at equilibrium, which balances the amount of heat released by the heater core 7.
Therefore, the heat radiation amount of the vehicle interior heater 7 can be increased at an early stage, and the effectiveness of the heater core 7 is improved.

The above-described effects are particularly remarkable in an engine with a small heat generation amount such as a so-called direct injection engine in which fuel is directly injected into a combustion chamber. Cooling water temperature is second
When the predetermined temperature T ₂ is exceeded, the exhaust throttle valve 80 is opened and the load of the internal combustion engine is reduced, and the ECU 64 controls so that the fuel of the fuel amount during the normal operation is injected from the injector 58 into the cylinder 50. As a result, the combustion heat in the engine body 3 decreases and becomes the same as in normal operation.
Although the amount of cooling water received from the engine body 3 decreases, the temperature of the cooling water has already risen sufficiently before that, so the amount of heat released from the heater core 7 can be covered, and the effectiveness of the heater core 7 is stabilized. It can be kept in a closed state.

When the temperature of the cooling water further rises and exceeds the third predetermined temperature T ₃ , the flow path switching valve 15 closes the radiator bypass passage 19 side and opens the radiator 5 side to open the radiator bypass passage 19. The cooling water stops flowing, and the cooling water is circulated between the radiator 5 and the engine body 3 via the radiator side cooling water circulation circuit E, and the temperature of the cooling water is controlled by the radiator 5 to operate the engine 1. The temperature is adjusted to suit the condition.

FIG. 3 is a diagram showing the temperature rise characteristic of the cooling water at the engine start in the low temperature test (outside air temperature = −20 ° C.). In the figure, the flow control valve 23 and the exhaust throttle valve 8
0 shows the case of this embodiment equipped with both 0, shows the case where only the flow control valve 23 is provided without the exhaust throttle valve 80, and shows both the flow control valve 23 and the exhaust throttle valve 80 It shows the case where it is not done. From this figure, it can be seen that in the case of, the cooling water temperature rises better than in the case and the equilibrium temperature of the cooling water is increased, but the cooling water temperature hunts near the equilibrium temperature. On the other hand, in the case of the present embodiment, the temperature of the cooling water rises better, the equilibrium temperature of the cooling water can be increased, and even if the equilibrium temperature is reached, stable hunting does not occur. I understand.

[0073]

As described above, according to the internal combustion engine of the present invention, the internal combustion engine body, the fuel injection means, the exhaust passage, the heater for the passenger compartment, the heater side cooling water circulation circuit, and the heater side. A passenger compartment heater, which is a component of a cooling water circulation circuit, and which passes through the cooling water from the main body of the internal combustion engine toward the heater for the passenger compartment to a heater cooling water passage at a first predetermined temperature or lower. A flow rate control valve for reducing the amount of cooling water going to the exhaust passage, an exhaust throttle valve for throttling the exhaust passage when the temperature of the cooling water in the exhaust passage is below a second predetermined temperature, and an exhaust passage for throttling by the exhaust throttle valve. When the vehicle is warmed up, it is possible to quickly increase the temperature of the cooling water and shorten the warm-up time. The effectiveness of the heater can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a diesel engine as an internal combustion engine according to the present invention.

FIG. 2 is a flow chart of cooling water of a diesel engine as an internal combustion engine according to the present invention.

FIG. 3 is a cooling water temperature rise characteristic diagram showing the present invention and the prior art in comparison.

[Explanation of symbols]

1 ... Diesel engine (internal combustion engine) 3 ... Engine body (internal combustion engine body) 5 ... radiator 5a ... Radiator entrance 5b ... Radiator exit 7 ... Heater core for passenger compartment (heater for passenger compartment) 7a ... Entrance of heater core 7 for passenger compartment 7b ... Exit of heater core 7 for passenger compartment 9 ... Oil cooler 11 ... Cooling water external passage 12 ... Water jacket (cooling water internal passage) 12a ... Heater side opening of water jacket 12b ... Radiator side lower mouth of water jacket 12c ... Radiator side upper mouth of water jacket 13 ... Connecting passage to radiator 13a ... Entrance of connecting passage for radiator 14 ... Connecting passage for engine body 15 ... Flow path switching valve 17 ... Water pump 19 ... Radiator bypass passage 21. Passageway to heater core 23 ... Flow control valve 30 ... Cooling water communication passage for oil cooler 30a ... Radiator side end of cooling water communication passage for oil cooler 30b ... End of the cooling water communication passage for the oil cooler on the heater core side 32 ... passage 36 ... Water temperature sensor 50 ... Cylinder 52 ... Cylinder head 54 ... Intake manifold 56 ... Exhaust manifold 58 ... Injector (fuel injection means) 60 ... Injection pump (fuel injection means) 62 ... Revolution sensor 64 ... ECU (fuel increasing means) 66 ... Intake pipe 68 ... Exhaust pipe (exhaust passage) 70 ... Turbocharger 72 ... Turbine 74 ... Compressor 76 ... Intercooler 78 ... Pressure control valve 80 ... Exhaust throttle valve 80a ... Valve 80b ... Actuator 82 ... Exhaust gas recirculation passage 82a ... bending point 84 ... EGR valve 86 ... Intake air temperature sensor 88 ... Accelerator sensor 90 ... Speed sensor A: Cooling water circulation device for internal combustion engine E ... Radiator side cooling water circulation circuit F: Heater side cooling water circulation circuit G: Radiator bypass circuit

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F01P 3/20 F01P 7/16 F02D 9/04 F02D 41/06

Claims (2)

(57) [Claims] 1. An internal combustion engine body having a cooling water internal passage through which cooling water for cooling a cylinder flows, fuel injection means for injecting fuel into the cylinder of the internal combustion engine body, and inside the cylinder of the internal combustion engine body. An exhaust passage for discharging exhaust gas generated by burning fuel in a vehicle, a heater for a vehicle compartment using a part of the cooling water as a heat medium, a cooling water internal passage for the internal combustion engine body, and a vehicle heater And a heater-side cooling water circulation circuit for circulating the cooling water between the heater side cooling water circulation circuit and the heater side cooling water circulation circuit, which is a constituent member of the heater side cooling water circulation circuit and passes the cooling water from the internal combustion engine body toward the vehicle interior heater. An internal combustion engine comprising a water passage, and a flow rate control valve for reducing the amount of cooling water directed to a passenger compartment heater when the cooling water temperature is equal to or lower than a first predetermined temperature. Before From the first predetermined temperature
Is also provided with an exhaust throttle valve that throttles the exhaust passage when the temperature is equal to or lower than the second predetermined temperature that is set to a large value, and when the exhaust passage is throttled by the exhaust throttle valve, the amount of fuel injected from the fuel injection means is increased. An internal combustion engine comprising fuel increasing means. 2. The heat generated from the internal combustion engine body is transferred to the cold
If absorbed water is absorbed while passing through the cooling water internal passage,
A radiator that releases heat from heated cooling water to the atmosphere
When, Flow cooling water from the cooling water internal passage to the radiator.
Is the connecting passage to the radiator and the cooling water on the radiator side?
Connection passage to the engine body that flows through the cooling water inside passage
Radiator side cooling water circulation circuit that circulates cooling water between
Road, Bypassing the radiator to the cooling water internal passage
A radiator bypass passage provided for flowing cooling water, The temperature of the cooling water is set higher than the first predetermined temperature.
When the temperature is lower than the third predetermined temperature, the radiator is
Close the radiator side and open the radiator bypass passage side.
A flow path switching valve that allows cooling water to flow to the bypass passage, The internal combustion engine according to claim 1, further comprising: