JP2000002169A - Internal-combustion engine with combustion type heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a firing source certainly in a combustion type heater and perform good purification of exhaust gas while deterioration of the emission is precluded. SOLUTION: An engine 1 includes a combustion type heater 17 which is actuated when the engine 1 is in the specified operating condition for raising the temp. of the cooling water and is connected in bypass form for the suction pipe 23 of the engine 1 passing via an air supply line 33, combustion chamber and combustion gas exhaust passage 35, and an intake throttle valve 20 is installed on the suction pipe 23 in its part downstream of the connecting point of the heater 17 with the suction pipe 23. A catalyst converter 39 is provided in the exhaust system of the engine 1, and the intake throttle valve 20 is throttled when a rise request for the catalyst temp. is placed, and it is arranged so that the heater 17 is actuated at least when the throttle valve 20 is throttled.

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 having a combustion heater, and more particularly to an internal combustion engine having a combustion heater for introducing combustion gas into an intake system of the internal combustion engine in order to promote warm-up of the internal combustion engine. .

[0002]

2. Description of the Related Art For example, Japanese Patent Application Laid-Open No. 62-75069 discloses a method of starting an internal combustion engine in a cold state by warming engine cooling water by using combustion heat generated by a combustion heater attached to an intake passage of the internal combustion engine. It shows the technology for improving the performance and promoting warm-up.

[0003] The combustion type heater described in this publication is attached to the intake passage through an intake duct and an exhaust duct. Then, air required for combustion is supplied from an intake passage via an intake duct, and combustion gas is discharged to the intake passage via an exhaust duct. The hot combustion gas emitted by the combustion heater is
After passing through the intake passage, it reaches the internal combustion engine body and warms the engine cooling water in the water jacket. Also, in the intake passage,
An opening / closing valve for opening and closing the intake passage, that is, a so-called intake throttle valve, is provided between the connection point with the intake duct and the connection point with the exhaust duct. The intake throttle valve is fully closed before the internal combustion engine is started, and is half-closed (half-opened) or fully opened for a while after the start of the internal combustion engine, thereby adjusting the amount of combustion air supplied to the combustion heater. By this adjustment, warm-up of the internal combustion engine and startability are improved.

On the other hand, although not described in the above-mentioned publication, it is conceivable that an exhaust system of an internal combustion engine is provided with a catalytic converter as exhaust gas purifying means. In this case, in order for the catalyst of the catalytic converter to function effectively, the catalyst must be raised to a temperature at which it works. Therefore, for example, if the internal combustion engine is placed in an idling state and the temperature of the exhaust gas emitted from the internal combustion engine is increased at that time, the temperature of the exhaust passage also becomes higher. Exhaust gas purification can be performed quickly.

[0005]

By the way, in order to raise the temperature of the exhaust gas emitted from the internal combustion engine, it is simply necessary to burn a large amount of fuel in the combustion chamber. However, as described in the case of idling, usually, during idling, a large amount of fuel is not burned, and instead the amount of intake air is reduced by increasing the throttle amount of the intake throttle valve, that is, the air supplied to the cylinder of the internal combustion engine. The amount of fuel is increased relative to the amount. However, this increases the intake resistance in the intake passage and increases the differential pressure between the intake side and the exhaust side of the combustion type heater. For this reason, the speed of the air flowing through the combustion type heater increases, and it is difficult for a lighter or a match to ignite in strong winds. is there. Also,
If the type of fire is difficult or if it is extinguished immediately, the A / F of the combustion heater set for each vehicle type or type of internal combustion engine will deviate significantly from a predetermined value, which is not preferable.

Further, when the intake throttle valve is throttled, the amount of intake air entering the cylinder of the internal combustion engine decreases, so that the air density, that is, the mass of oxygen decreases. For this reason, smoke is likely to occur during combustion of the internal combustion engine. That is, the emission may be deteriorated. The present invention has been made in view of the above circumstances, and has the following effects in an internal combustion engine having a combustion heater to promote warm-up and improve startability of the internal combustion engine. It is a technical object to provide an internal combustion engine having a combustion-type heater that can perform the above-described heating. Ensure the fire of the combustion type heater. Prevent emission deterioration. Improve exhaust gas purification.

[0007]

In order to solve the above problems, an internal combustion engine having a combustion type heater according to the present invention has the following configuration. (1) A combustion chamber, an air supply path for supplying air for combustion to the combustion chamber, a fuel supply path for supplying combustion fuel to the combustion chamber, and the combustion supplied to the combustion chamber by the fuel supply path. A combustion type heater comprising: an ignition device for igniting fuel; and a combustion gas discharge passage for discharging combustion gas emitted from the combustion fuel, which has been burned in the combustion chamber by the ignition by the ignition device, from the combustion chamber. In an internal combustion engine having a combustion type heater which operates when the engine is in a predetermined operating state and raises the temperature of an engine-related element, the combustion type heater is connected to an intake passage of the internal combustion engine by the air supply passage, the combustion The combustion chamber is connected to the combustion gas discharge passage in a bypass shape, and the suction air flowing through the intake passage is located downstream of the connection point of the combustion type heater with the intake passage. Characterized by installing an intake throttle valve to control the amount of.

[0008] Here, the "predetermined operating state of the internal combustion engine" means that the internal combustion engine is running, or after the internal combustion engine is started, or when the calorific value of the internal combustion engine itself is small in cold or extremely cold conditions. For example, when the fuel consumption is low) and when the amount of heat received by the internal combustion engine is small due to the small amount of heat generated by the internal combustion engine itself. The cold state is a temperature of about −10 ° C. to 15 ° C.
Extreme cold is a temperature of -10 ° C or less.

"Engine-related elements" include engine cooling water,
It is the internal combustion engine itself that introduces the combustion gas of the combustion type heater into the intake air.

In the internal combustion engine having the combustion heater according to the present invention, an intake throttle valve for controlling an amount of intake air flowing through the intake passage is provided downstream of a connection point between the combustion heater and the intake passage in the intake passage. Therefore, of the intake passage,
There is no intake throttle valve between the connection point with the air supply path and the connection point with the combustion gas discharge path. Therefore, a pressure difference occurs in a portion of the intake passage between a portion where the air supply passage connects to the intake passage and a portion where the combustion gas discharge passage connects to the intake passage, regardless of whether the intake throttle valve is operated. Absent. Therefore, the air speed in the combustion heater main body connected to the intake passage via the air supply passage and the combustion gas discharge passage does not become excessive. Therefore, since there is no strong ventilation in the combustion chamber to such an extent that a fire to the combustion type heater cannot be generated, the fire type of the combustion type heater can be ensured.

Further, since the type of fire can be ensured, the A / F of the fuel-combustion heater set for each vehicle type or each type of internal combustion engine does not deviate from a predetermined value. (2) In (1), the intake throttle valve may be a throttle valve for controlling output of the internal combustion engine. (3) In the above (1), the intake throttle valve may be a throttle valve for controlling the state of the internal combustion engine. (4) In the above (1) to (3), it is preferable that a connection point of the air supply passage with the intake passage is located upstream of a connection point of the combustion gas discharge passage with the intake passage. Since the air supply path and the combustion gas discharge path of the combustion heater do not open directly to the atmosphere, a noise reduction effect can be expected. (5) In the above (1) or (4), the internal combustion engine has a catalyst in its exhaust system, and when there is a request to increase the temperature of the catalyst, the intake throttle valve is throttled, and at least the intake throttle is reduced. It is preferable that the combustion type heater be operated when the valve is throttled.

Here, "when there is a request for raising the temperature of the catalyst" means that, depending on the situation where the internal combustion engine is placed, it is necessary to raise the catalyst temperature. CPU (central control unit) which is the central part of the control unit
Processing unit), for example, when the temperature is about -10 ° C. to about 15 ° C.,
When the internal combustion engine is operating, after the internal combustion engine is started, or when the calorific value of the internal combustion engine itself is small (for example, when the fuel consumption is low), in extremely cold temperatures of 10 ° C. or less.
And when the amount of heat received by the cooling water is small due to the small amount of heat generated by the internal combustion engine itself, for example, when the engine 1 is in an idling state.

In this case, in the internal combustion engine having the combustion type heater according to the present invention, the intake throttle valve is throttled when there is a request for increasing the temperature of the catalyst. Since the heater operates, the inside of the cylinder of the internal combustion engine is heated by the high-temperature combustion gas flowing out of the combustion type heater and flowing into the combustion chamber of the internal combustion engine without having to raise the exhaust gas temperature by narrowing the intake throttle valve. Warm enough. Accordingly, the temperature in the cylinder of the internal combustion engine can be increased without increasing the degree of throttle of the intake throttle valve, so that it is not necessary to greatly reduce the intake throttle valve as in the prior art. Therefore, the amount of intake air entering the cylinder of the internal combustion engine does not decrease significantly, so that generation of smoke can be suppressed. Therefore, emission does not deteriorate. (6) In the above (5), the operation of the combustion type heater may precede the closing of the intake throttle valve.

In this case, since the combustion heater operates prior to closing the intake throttle valve, the temperature of the internal combustion engine due to the combustion gas emitted from the combustion heater is detected by, for example, a cooling water temperature sensor or the like. By performing the closing control of the intake throttle valve in this way, the closing control of the intake throttle valve can be performed in a state where the amount of smoke generated is the least.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings. <First Embodiment> (Engine 1) The engine 1 as an internal combustion engine is a water-cooled type and has an engine body 3 provided with a water jacket (not shown) through which cooling water, which is one of engine-related elements, circulates.
And an intake device 5 for feeding air required for combustion into a plurality of cylinders (not shown) of the engine body 3, and an air-fuel mixture comprising the air related to the intake device 5 and fuel injected by a fuel injection device (not shown) The vehicle includes an exhaust device 7 that emits exhaust gas that has been burned in the air into the atmosphere, and a vehicle interior heater 9 that warms the interior of a vehicle on which the engine 1 is mounted.

(Intake Device 5) The intake device 5 has an air cleaner 13 that takes in fresh air into a cylinder as a start end of the intake device 5 and an intake port (not shown) of the engine body 3 as an end. In the meantime, there are provided an air flow meter 14, a compressor 15a of a turbocharger 15, which is an intake system structure, a combustion heater 17, which burns under atmospheric pressure, an intercooler 19, an intake throttle valve 20, and an intake manifold 21.

These intake system structures belong to another intake system structure and belong to an intake pipe 23 as an intake passage having a plurality of pipes.

(Intake Pipe 23) The intake pipe 23 includes a downstream connection pipe 27 which is in a pressurized state because the outside air entering the intake device 5 is forcibly pushed by the compressor 15a with respect to the compressor 15a. It can be roughly divided into the upstream connecting pipe 25 that is not so.

(Upstream Connection Pipe 25) One of the upstream connection pipes 25 is a rod-shaped main pipe 29 extending straight from the air cleaner 13 toward the compressor 15a in FIG.
And a branch pipe 31 for a heater as a branch pipe connected to the main pipe 29 in a bypass shape.

(Main Flow Pipe 29) The main flow pipe 29 has the air flow meter 14 and the outside air temperature sensor 32 at the center thereof. The air flow meter 14 will be described later.
Next, the outside air temperature sensor 32 will be described.

(External Air Temperature Sensor 32) An external air temperature sensor 32 is provided in the main pipe 29 near the downstream side of the air cleaner 13.
Is installed. The outside air A entering the main pipe 29 from the air cleaner 13 is supplied to the engine 1 and the combustion heater 17.
And the outside air temperature sensor 32 detects the temperature.

(Branch 31 for heater) Branch pipe 31 for heater
Has a substantially U-shaped overall shape, and includes a combustion heater 17 at an intermediate portion thereof. Also, the heater branch pipe 31
As another component member, a fresh air for connecting the upstream portion of the combustion type heater 17 in the air flow direction with the main flow pipe 29 and supplying fresh air to the combustion type heater 17 from the main flow pipe 29, that is, a new air supplied to the combustion type heater 17 for combustion. Combustion gas connecting the air supply pipe 33 serving as an air supply path for supplying air (pre-combustion air) a1, a downstream portion of the combustion type heater 17 in the air flow direction and the main flow pipe 29, and flowing out of the combustion type heater 17 (Combustion air) a combustion gas discharge pipe 35 as a combustion gas discharge path for discharging a2 to the main flow pipe 29. Therefore, the heater branch pipe 31 includes the air supply pipe 33 and the combustion gas discharge pipe 35.
The air is supplied to and discharged from the combustion type heater 17 through. Further, the air supply passage 33 and the combustion gas introduction passage 35
Since they are used only for the combustion type heater 17, they can be said to be members belonging to the combustion type heater 17.

(Connection points c1 and c2) Air supply pipe 3
Among the connection points c1 and c2 of the main pipe 3 and the combustion gas discharge pipe 35 with the main pipe 29, the connection point c1 is located on the upstream side of the main pipe 29 from the connection point c2. Therefore,
The outside air (fresh air) A from the air cleaner 13 is first distributed to the heater branch pipe 31 at the connection point c1 (hereinafter simply referred to as “air a1”).
9 into air a1 'heading toward the connection point c2. The air a1 branched at the connection point c1 returns to the main pipe 29 as the combustion gas a2 from the connection point c2 via the air supply pipe 33, the combustion heater 17 and the combustion gas discharge pipe 35.
Further, the combustion gas a2 and the air a1 'merge at the connection point c2 to become the combustion gas mixed air a3. The combustion gas mixed air a3 is provided as combustion air in the cylinder of the engine body 3. In general, the combustion gas of the combustion type heater has almost no smoke in a normal combustion state, in other words, a gas containing no carbon. The same applies to the combustion gas of the combustion type heater 17 according to this embodiment. Therefore, there is no problem even if the combustion gas a2 of the combustion heater 17 is used as intake air for the internal combustion engine.

(Downstream Connection Pipe 27) Downstream Connection Pipe 27
Is a pipe connecting the compressor 15a and the intake manifold 21, as shown in FIG. 1, and is L-shaped in this embodiment. In the downstream connecting pipe 27, an intercooler 19 and an intake throttle valve 20 are disposed at a central portion thereof and a portion near the intake manifold 21, respectively.

(Intercooler 19) Intercooler 1
Numeral 9 is for cooling the compression heat generated when the intake air is compressed by the compressor 15a, thereby preventing a decrease in the output of the internal combustion engine due to an increase in the intake air temperature.

(Intake throttle valve 20) Since the intake throttle valve 20 is attached to the portion near the intake manifold 21 as described above, the intake pipe 23 is more closely connected to the connection portion of the combustion type heater 17 in the intake pipe 23. And the combustion gas discharge passage 35, and is located downstream of the connection point c2. The intake throttle valve 20 is an intake amount control valve that controls the amount of intake air flowing through the intake pipe 23. By controlling the intake air amount by the intake throttle valve 20, the output state of the engine 1 is controlled, or the operating state of the engine 1 is controlled, such as stopping the engine 1. Further, when there is a request to increase the catalyst temperature of a later-described catalytic converter 39 belonging to the exhaust device 7, that is, it is necessary to increase the catalyst temperature of the catalytic converter 39 depending on the situation where the engine 1 is placed. When the computer that controls the entire engine 1, that is, the CPU that is the center of the ECU 46, determines, the intake throttle valve 20 is throttled. The case where it is necessary to increase the catalyst temperature is defined as the time when the internal combustion engine is operating, after the internal combustion engine is started, or when the calorific value of the internal combustion engine itself is small (for example, when the fuel consumption is low) in cold or extreme cold. And when the engine 1 is in an idling state because the amount of heat received by the cooling water is small due to the small amount of heat generated by the internal combustion engine itself. Also,
The term “cold” refers to a temperature of about −10 ° C. to 15 ° C., and the term “extremely cold” refers to a temperature of −10 ° C. or lower. Note that the case where the catalyst temperature needs to be raised is referred to as “when there is a request for the exhaust gas temperature increase control” for convenience. Also,
This request for the exhaust gas temperature increase control means that the engine 1 is in an operating state in which the combustion heater 17 needs to be activated.
It may be said that there is.

(Exhaust Device 7) On the other hand, the exhaust device 7 has an exhaust system structure in which an exhaust port (not shown) of the engine body 3 is set as a start end of the exhaust device 7 and from there to a muffler 41 which is an end of the exhaust device 7. An exhaust manifold 38, a turbine 15b of the turbocharger 15, and a catalytic converter 39 having a catalyst are provided on an exhaust pipe 42, which is also an exhaust system structure. The air flowing through the exhaust device 7 is denoted by reference numeral a4 as the exhaust gas of the engine 1.

(Combustion heater 17) Next, the combustion heater 1
The structure of 7 is shown schematically in FIGS.

The combustion type heater 17 is controlled by the CPU to control its combustion state, and operates before the intake throttle valve 20 needs to be throttled.

The combustion heater 17 is connected to the water jacket of the engine body 3, and the combustion heater 17 has an engine cooling water passage 17a through which engine cooling water flows from the water jacket. The engine cooling water (indicated by a broken arrow in FIG. 2) flowing through the engine cooling water passage 17a is supplied to the combustion chamber 1 formed inside the combustion type heater 17.
7d, while passing through the combustion chamber 1
It gets warmed by the heat from 7d.

(Combustion Chamber 17d) The combustion chamber 17d includes a combustion cylinder 17b as a combustion chamber for emitting a flame, and a cylindrical partition wall 17c that covers the combustion cylinder 17b to prevent the flame from leaking outside. The combustion chamber 17d is defined in the partition 17c by covering the combustion cylinder 17b with the partition 17c. And
The partition wall 17c is also covered with the outer wall 43a of the combustion type heater 17,
There is a space between them. By setting this interval,
The engine cooling water passage 17a is formed between the inner surface of the outer wall 43a and the outer surface of the partition wall 17c.

The combustion chamber 17d is connected to the air supply pipe 3
It has an air supply port 17d1 and an exhaust port 17d2 which are directly connected to the fuel cell 3 and the combustion gas discharge pipe 35, respectively.

Then, from the air supply pipe 33 to the air supply port 1
The air a1 that has entered the combustion chamber 17d via 7d1 reaches the exhaust outlet 17d2 via the combustion chamber 17d, and then from the combustion gas exhaust pipe 35 to the main pipe 29 as described above as combustion gas a2. Flow in. Therefore, the combustion chamber 17d
Is in the form of a series of air flow passages for passing air a1 that changes into combustion gas a2 in the combustion type heater 17.

After the combustion type heater 17 burns, the combustion gas a2 returns to the main pipe 29 via the combustion gas discharge pipe 35.
Has heat because it is the combustion gas discharged from the combustion heater 17. Until the combustion gas a2 having this heat exits from the combustion heater 17 to the combustion gas discharge pipe 35, the heat of the combustion gas a2 is transferred to the engine cooling water flowing through the engine cooling water passage 17a through the partition wall 17c. The engine cooling water is warmed as described above, and the warmed engine cooling water is sent to the water jacket of the engine 1 to warm up the engine body 3.

(Combustion cylinder 17b) The combustion cylinder 17b is
Fuel supply pipe 17 connected to a fuel pump (not shown)
e, and receives the pump pressure of the fuel pump therefrom to supply combustion fuel to the combustion cylinder 17b. Therefore, the fuel pump and the fuel supply pipe 17e can be said to be fuel supply means. The amount of fuel supplied by the operation of the fuel pump is calculated as an integrated value of the amount of fuel supplied from the start of operation of the fuel pump.
7 is temporarily stored in a RAM (random access memory) of the ECU 46 that controls the combustion state, and is called up by the CPU, which is a central part of the ECU 46, as needed.

(Liquefied fuel 18) The fuel for combustion supplied is
The liquefied fuel 18 is converted into a vaporized fuel 18 ′ through a fuel vaporization section 17 f shown in FIG. 3, and the vaporized fuel 18 ′ is ignited by a glow plug 17 g that generates heat by energization from a battery (not shown) which is an ignition device. . When the glow plug 17g generates heat, the actual elapsed time from the start of energization is counted by the timer Tim (see FIG. 1), and the value is also temporarily stored in the RAM. Then, it is called by the CPU as needed.

(Ion Sensor 17h and Fuel Heating and Evaporating Plate 17i) Reference numerals 17h and 17i in FIG. 3 denote an ion sensor as an ignition sensor and a fuel heating and evaporating plate, respectively. The vaporized fuel 18 'is ignited near the fuel heating and evaporating plate 17i, and a fire type F' which is a source of the flame F is formed. What blows the fire type F ′ into a flame is the blower fan 45.

(Blower Fan 45) The blower fan 45 is located downstream of the combustion chamber 17d in the form of an air flow passage.
The output of the blower fan 45 is adjusted by controlling the operation of the CPU of the ECU 46. This output adjustment changes the amount of air flowing through the combustion chamber 17d. Therefore, the amount of air flowing through the combustion chamber 17d can be controlled by adjusting the output of the blower fan 45.

(Circulation of Engine Cooling Water) Next, the circulation of the engine cooling water to the engine cooling water passage 17a will be described with reference to FIGS.
This will be described with reference to FIG.

(Engine Cooling Water Passage 17a) The engine cooling water passage 17a has a cooling water inlet 17a1 connected to the water jacket of the engine body 3 and an engine cooling water outlet 17a2 connected to the vehicle interior heater 9. And

(Water lines W1 to W3) Engine cooling water inlet 1
A water pipe W1 is connected between the engine body 7a1 and the engine body 3, and a water pipe W2 is connected between the engine cooling water discharge port 17a2 and the vehicle interior heater 9.

The combustion heater 17 is connected to the water jacket of the engine body 3 and the heater 9 for the passenger compartment through the water pipes W1 and W2.
Further, the vehicle interior heater 9 and the engine body 3 are also connected via a water pipe W3.

Therefore, the engine cooling water in the water jacket of the engine body 3 flows from the engine cooling water inlet 17a1 to the combustion heater 17 via the water pipe W1 in the order of flow, and is heated there. The warmed engine coolant flows from the engine coolant outlet 17a2 of the combustion heater 17 to the vehicle interior heater 9 via the water pipe W2. Then, the engine cooling water is subjected to heat exchange by the vehicle interior heater 9 to lower the temperature, and then returns to the water jacket via the water pipe W3. A water temperature sensor 47 for detecting the temperature of the engine cooling water is attached to the water jacket.

As described above, the engine cooling water is supplied to the water pipe W1.
Circulates between the engine body 3, the combustion type heater 17, and the vehicle interior heater 9 via the water pipe W2 and the water pipe W3.

(Electrical connection of sensors and the like to ECU 46)
The ECU 46 also includes an ion sensor 17h, an outside air temperature sensor 32, a water temperature sensor 47, and a timer Tim,
It is electrically connected to the blower fan 45 and the fuel pump. The CPU appropriately controls the combustion state of the combustion heater 17 in accordance with the parameters of the sensors 17h, 32, and 47, the timer Tim, the output value of the blower fan 45, and the fuel pump. 17
Maintain the best momentum, size and temperature of the flame.
Further, the temperature of the exhaust gas of the combustion heater 17 and the air-fuel ratio of the combustion heater 17 are adjusted by controlling the combustion state of the combustion heater 17 by the CPU. Further, the CPU controls the degree of throttle of the intake throttle valve 20 in accordance with each of the parameters, together with the control of the combustion heater 17.

(Air flow meter 14)
Is located between a connection point c1 of the intake air supply path 33 and a connection point c2 of the combustion gas introduction path 35 in the main pipe 29.

Incidentally, since an air flow meter is generally an air resistance that hinders the flow of air flowing through an intake passage, the pressure of air flowing out of the air flow meter is smaller than the pressure of air entering the air flow meter. That is, the air flow meter has a difference between the air pressure at the inlet and the air pressure at the outlet. The airflow meter, which is an intake resistance having a difference in air pressure between the inlet and the outlet, is connected to the main flow pipe 29.
The main line portion to the combustion type heater 17 connected in a bypass manner, that is, a connection point c1 between the main flow pipe 29 and the air supply passage 33 of the main flow pipe 29 and a connection point c2 between the main flow pipe 29 and the combustion gas introduction path 35 Part 29 between
m, the pressure difference is large between the connection points c1 and c2, that is, between the inlet of the air supply passage 33 and the outlet of the combustion gas introduction passage 35, so that the pressure difference between the air supply passage 33 and the combustion gas introduction passage 35 is large. There is a possibility that the air flow velocity in the combustion chamber 17d of the located combustion type heater 17 becomes excessively large and the ignition performance deteriorates.

Therefore, it is preferable that the air flow meter has a small pressure difference between the inlet side and the outlet side, for example, a hot wire type or film type air flow meter.

(Operation Control Execution Routine of Intake Throttle Valve 20) Next, an operation control execution routine of the intake throttle valve 20 will be described with reference to FIG.

This routine is a part of a normal flowchart (not shown) for driving the engine 1 and includes the following steps S101 to S103. The flowchart including these steps corresponds to the RO of the ECU 46.
It is stored in M. The processing in each step of each flowchart is entirely performed by the CPU of the ECU 46. In addition, using the symbol S, for example, step 10
If it is 1, it is abbreviated as S101.

After the engine 1 is started, when the processing shifts to this routine, first in S101, it is determined whether or not the request flag for the exhaust gas temperature rise control has been set, that is, the engine 1 is brought into an operation state in which the combustion heater 17 needs to be activated. Determine if there is. In this case, the temperature of the engine cooling water is naturally low, and the case where the temperature of the engine cooling water is lower than a predetermined temperature, for example, 60 ° C., is exemplified as the case where the combustion heater 17 needs to be activated.

The temperature of the engine cooling water is detected by a water temperature sensor 47 associated with the water jacket of the engine body 3. S
If an affirmative determination is made in 101, the process proceeds to S102. In S102, it is determined whether or not the combustion type heater 17 is operating, that is, whether or not the combustion is performed by emitting a flame.

If the temperature of the engine cooling water is higher than the predetermined temperature exemplified as 60 ° C., it means that the engine 1 is in an operating state where it is not necessary to activate the combustion type heater 17, so that the answer in S101 is NO. A determination is made and this routine ends.

In S103, the control for closing the intake throttle valve 20 is executed.

The above is the description of the engine 1 having the combustion heater 17 according to the embodiment of the present invention.

<Operation and Effect of Embodiment> Next, the operation and effect of the embodiment of the present invention will be described.

In the engine 1, an intake throttle valve 20 is installed in the intake pipe 23 downstream of a position where the combustion heater 17 is attached. Therefore, the intake throttle valve 20 does not exist in a portion 29m of the main flow pipe 29 of the intake pipe 23 between the connection point c1 with the air supply path 33 and the connection point c2 with the combustion gas discharge path 35. Therefore, the air supply passage 35 and the combustion gas discharge passage 3 connected to the intake pipe 23 respectively.
In the period between 5, regardless of whether the intake throttle valve 20 is operated or not,
No pressure difference occurs. For this reason, the air velocity in the combustion chamber 17d of the combustion heater 17 connected to the intake pipe 23 via the air supply passage 33 and the combustion gas discharge passage 35 does not become excessive. Therefore, since the ventilation which is so strong that the fire to the combustion type heater 17 cannot be generated does not occur in the combustion chamber 17d, the fire type F ′ of the combustion type heater 17 can be ensured.

Also, since the fire type F 'can be ensured,
The A / F of the fuel-combustion heater set for each vehicle type or engine type does not deviate from a predetermined value.

Further, the air supply path 3 of the combustion heater 17
3 and the combustion gas discharge path 35 are not directly open to the atmosphere, so that an effect of reducing noise can be expected.

Further, in the engine 1, when there is a request for the exhaust gas temperature rise control, the intake throttle valve 20 is throttled, and at least at this time, the combustion heater 17 is operated. Without increasing the temperature of the exhaust gas of the engine 1, the combustion chamber 17 is sufficiently warmed by the high-temperature exhaust gas flowing into the combustion chamber of the engine 1 from the combustion heater 17. Therefore, the cylinder temperature of the engine 1 can be increased without increasing the throttle of the intake throttle valve 20 so much, and it is not necessary to increase the cylinder temperature by greatly reducing the intake air amount. Therefore, generation of smoke from the engine 1 can be suppressed, so that emission does not deteriorate.

The operation of the combustion heater 17 precedes the closing control of the intake throttle valve 20. Therefore, if various temperatures relating to the engine 1 due to the combustion gas emitted from the combustion heater 17 are detected by various temperature sensors, and the closing control of the intake throttle valve is performed in accordance with the detected temperatures, the closing degree of the intake throttle valve 20 is smoked. Control can be performed with the least amount of generation.

[0062]

As described above, in the internal combustion engine having the combustion type heater according to the present invention, the fire type of the combustion type heater is ensured, and the purification of the exhaust gas is improved while preventing the deterioration of the emission. Can be

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an internal combustion engine having a combustion heater according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of a combustion heater according to an embodiment of the present invention.

FIG. 3 is a sectional view taken along a virtual section including the line III-III of FIG. 2 and viewed in the direction of the arrow;

FIG. 4 is a flowchart illustrating a control routine for controlling the operation of the intake throttle valve according to the embodiment of the present invention;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine (internal combustion engine) 3 ... Engine main body (main body of internal combustion engine) 5 ... Intake device 7 ... Exhaust device 9 ... Heater for vehicle interior 13 ... Air cleaner 14 ... Air flow meter 15 ... Turbocharger 15a ... Compressor 15b ... Turbocharger Turbine 17 Combustion heater 17a Engine cooling water passage of combustion heater 17a1 Engine cooling water inlet 17a2 Engine cooling water discharge 17b Combustion cylinder (combustion chamber) 17c Cylindrical partition wall 17d Combustion chamber 17d1 Air Supply port 17d2 ... Exhaust exhaust port 17e ... Fuel supply pipe (fuel supply means) 17f ... Fuel vaporization section 17g ... Glow plug (ignition device) 17h ... Ion sensor 17i ... Fuel heating evaporation plate 18 ... Liquid fuel 18 '... Vaporized fuel 19 ... intercooler 20 ... intake throttle valve 21 ... intake manifold 23 ... intake pipe 25 ... Flow-side connecting pipe 27 ... Downstream-side connecting pipe 29 ... Main-flow pipe 29m ... Part between connection points c1 and c2 in the main-flow pipe 31 ... Branch for heater 32 ... Outside air temperature sensor 33 ... Air supply pipe (air supply path) 35: Combustion gas discharge pipe (combustion gas discharge path) 38: Exhaust manifold 39: Catalytic converter 41: Muffler 42: Exhaust pipe 43a: Outer wall 45: Ventilation fan 46: ECU 47: Water temperature sensor W1: Water pipe W2: Water pipe W3 ... water pipe F ... flame F '... fire type Tim ... timer A ... outside air a1 ... branching off from outside air A at connection point c1 and air supply pipe 3
Air flowing through 3 (fresh air) a1 '... Air flowing through the main pipe 29 toward the connection point c2 a2 ... Combustion gas of the combustion heater 17a3 ... Air mixed with combustion gas a2 and air a1'a4 ... Engine 1 Exhaust gas c1: Connection point between the air supply pipe 33 and the main pipe 29 (connection point of the air supply path with the intake passage) c2 ... Connection point between the combustion gas discharge path 35 and the main flow pipe 29 (the connection point of the combustion gas discharge path) Connection point with the intake passage)

Claims (6)

[Claims] A combustion chamber; an air supply passage for supplying combustion air to the combustion chamber; a fuel supply passage for supplying combustion fuel to the combustion chamber; and a fuel supply passage for supplying the combustion chamber with the fuel supply passage. A combustion heater comprising: an ignition device that ignites the combustion fuel; and a combustion gas discharge passage that discharges, from the combustion chamber, combustion gas emitted by the combustion fuel that has been burned in the combustion chamber by the ignition by the ignition device. An internal combustion engine having a combustion-type heater that operates when the internal combustion engine is in a predetermined operating state and raises the temperature of an engine-related element, wherein the combustion-type heater is provided to an intake passage of the internal combustion engine,
The air supply passage, the combustion chamber, and the combustion gas discharge passage are connected in a bypass shape, and the intake air flowing through the intake passage is located downstream of a connection point of the combustion heater with the intake passage in the intake passage. An internal combustion engine having a combustion type heater, wherein an intake throttle valve for controlling the amount is provided. 2. The internal combustion engine according to claim 1, wherein the intake throttle valve is a throttle valve for controlling the output of the internal combustion engine. 3. The internal combustion engine having a combustion type heater according to claim 1, wherein the intake throttle valve is a throttle valve for controlling a state of the internal combustion engine. 4. A connection point of the air supply passage with the intake passage is located upstream of a connection point of the combustion gas discharge passage with the intake passage. An internal combustion engine having the combustion type heater according to any one of the above. 5. The internal combustion engine has a catalyst in an exhaust system thereof, and throttles the intake throttle valve when there is a request to increase the temperature of the catalyst. The internal combustion engine having the combustion type heater according to claim 1 or 4, wherein the heater is operating. 6. The internal combustion engine having a combustion heater according to claim 5, wherein the operation of the combustion heater precedes the closing of the intake throttle valve.