JP2001173434A - Internal combustion engine with fuel burning heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine with a fuel burning heater capable of sufficiently purifying exhaust gas even immediately after the start of the engine. SOLUTION: The internal combustion engine comprises: the fuel burning heater 17; a exhaust emission control catalyst for purifying the exhaust gas; a combustion gas introducing means to the upstream side of the catalyst having a combustion gas guiding pipe 34 to the upstream side of the catalyst for introducing combustion gas emitted from the fuel burning heater 17 to a portion U of an exhaust passage 17, when the heater 17 is needed to be operated, that is, when it is cold and the engine 1 is cold and an ignition switch is operated in a stop state without cracking to enable the heater 17 to be operable; a combustion gas guiding means to the intake side, which reduces the introduced amount or stops the introduction of the combustion gas supplied to the upstream side of the catalyst by the combustion gas introducing means, changes part or all of a combustion gas flow to direct to an engine intake side, and has a combustion gas guiding pipe 32 to the intake passage side for guiding at least a part of the changed combustion gas to an intake passage 14, when starting cranking.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion type heater which is used for warming up an engine, for warming up a catalyst, for heating a vehicle equipped with an internal combustion engine, etc., by utilizing combustion heat of a combustion type heater attached to an internal combustion engine. Internal combustion engine having the same.

[0002]

2. Description of the Related Art Fuel does not burn unless it exceeds a certain temperature. For this reason, even if fuel is supplied into the cylinder, if the temperature in the cylinder is too low, combustion does not occur, and thus the operation of the engine (engine startability) is deteriorated. Therefore, a method of heating the intake air is generally performed to improve the degree of engagement of the engine.

In the case of a lean-burn engine, for example, a diesel engine, the ignition method of a diesel engine is based on the heat of compression of air. The more complicated the shape, the higher the rate of heat loss. Therefore, a glow plug is used to assist ignition in the combustion chamber through electric current when starting the engine.

[0004] In addition, the interior of the vehicle is heated by utilizing the heat generated during operation of the engine. However, a lean burn engine such as a diesel engine originally generates a small amount of heat. For this reason,
In particular, when the outside air temperature is in a low temperature such as a cold temperature of about -10 to 15 ° C. or an extremely low temperature of less than that, when the heat generated by the lean-burn engine alone is not sufficient to heat the vehicle interior. There are many.

In view of the above, the engine is provided with a combustion type heater for the purpose of promoting warm-up, improving the startability, and improving the heating performance of the vehicle cabin, and the above-mentioned problem has been solved by utilizing the combustion heat generated from the combustion type heater. The technology is disclosed in, for example, JP-A-60-79.
No. 149.

In this technique, a high-temperature combustion gas discharged from a combustion heater is introduced into an intake system at the time of engine start to heat intake air, thereby promoting the warm-up. On the other hand, although not disclosed in the above-mentioned publication, a catalytic converter as an exhaust gas purifying means including an exhaust gas purifying catalyst may be installed in the engine exhaust system.

In this case, in order to purify the exhaust gas, it is necessary to raise the catalyst temperature of the catalytic converter to a so-called activation temperature. The activation of the catalyst means that the catalyst can exhibit its exhaust purification function, and the activation of the exhaust gas of the engine has been used to activate the catalyst.

[0008] However, in the prior art that attempts to activate the catalyst by using the heat of the exhaust gas of the engine, the exhaust gas is not discharged from the engine while the engine is stopped, so that the catalytic converter is not used. The catalyst is in an unactivated state (inactive state).

Therefore, even if the engine once started is turned off, and the engine is restarted from a state in which the engine has cooled down, the catalyst is in an inactive state immediately after that, so that the exhaust gas is immediately exhausted. It is possible that gas cannot be purified. This is particularly noticeable in cold weather.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a problem to be solved at the time of engine start before exhaust gas flows into an engine exhaust passage. In order to activate the exhaust gas purification catalyst provided in the exhaust passage, the catalyst is warmed up before cranking by a combustion type heater attached to the internal combustion engine, and as a result, the internal combustion engine A technical problem is to make it possible to sufficiently purify exhaust gas even immediately after starting.

[0011]

The present invention employs the following means in order to solve the above-mentioned problems. (1) The present invention provides a combustion type heater attached to an internal combustion engine,
An exhaust purification catalyst installed in the engine exhaust passage for purifying exhaust gas flowing through the engine exhaust passage; and an exhaust purification catalyst for stopping the combustion type heater when the internal combustion engine is in a predetermined stop state and the combustion type heater needs to be operated. A combustion gas catalyst upstream introduction means for introducing the exhausted combustion gas into the engine exhaust passage at a location upstream of the installation location of the exhaust gas purification catalyst,
When the internal combustion engine starts cranking, the introduction of the combustion gas to the upstream side of the catalyst by the combustion gas catalyst upstream side introduction means is reduced or stopped, and a part or all of the flow of the combustion gas is changed to the engine intake side. An internal combustion engine having a combustion heater, comprising: combustion gas intake side guide means for guiding at least a portion of the combustion gas whose flow direction has been changed to the intake side into the engine intake passage.

Here, "the internal combustion engine is in a predetermined stop state" means, for example, that the driver operates an ignition switch, which is a switch of an electric system, in a stop state in which the internal combustion engine is not yet cranked. This means that the combustion type heater is in an operable state.

"When it is necessary to operate a combustion type heater"
The term refers to a case where the outside air temperature is at a low temperature equal to or lower than the cold temperature, and thus the catalyst is in an inactive state. Note that the term “cold” refers to a range in which the outside air temperature is approximately -10 ° C. to 15 ° C .;

The "combustion gas catalyst upstream introduction means" and the "combustion gas intake side guide means" are, for example, a passage for guiding the combustion gas discharged from the combustion heater to a position upstream of the catalyst in the engine exhaust passage and an engine intake passage, respectively. And, for example, these two paths are joined so as to be branched on the way to the exhaust side and the intake side, and the direction of the flow of the combustion gas discharged from the combustion type heater at the branch point is set to the upstream side of the catalyst. Or you can change it as needed on the intake side,
For example, it refers to a device provided with a valve device such as a three-way valve.
Further, it is preferable that the valve device can be operated and controlled by an electronic control unit for engine control (hereinafter referred to as “ECU”).

"Cranking" means that the crankshaft is rotated by an engine start assisting means such as a starter motor attached to the engine body. "Starting of the internal combustion engine" refers to the start of movement of the engine itself, in which the crankshaft starts to rotate due to the reciprocating motion of the piston obtained during the explosion stroke during the operation stroke of the internal combustion engine, and is caused by cranking.

According to the present invention, when the internal combustion engine is in a predetermined stop state and it is necessary to operate the combustion type heater, the combustion gas discharged from the combustion type heater is supplied from the engine exhaust passage through the exhaust gas purifying catalyst installation point. Is introduced into the upstream portion, so that the catalyst can be activated before the internal combustion engine is started.

Therefore, if the combustion temperature of the combustion heater is adjusted by adjusting the output of the combustion heater and the catalyst is already sufficiently activated when the internal combustion engine is started, the start of the internal combustion engine can be started. Immediately after, sufficient exhaust purification can be performed.

When the cranking is started, the introduction of the combustion gas to the upstream side of the catalyst is reduced or stopped to guide a part or all of the flow of the combustion gas to the engine intake passage. When a part of the combustion gas flows to the engine intake side, a part of the combustion heat of the combustion type heater is introduced into the cylinder via the combustion gas intake side guide means and the remaining heat not flowing to the engine intake side. Since the combustion gas flows to the upstream side of the catalyst via the upstream side of the combustion gas catalyst introduction means, the temperature of the catalyst is also increased by the combustion heat of the remaining combustion gas.

Therefore, when it is desired to increase the promotion amount of the engine warm-up, it is possible to warm up the engine faster by flowing more combustion gas toward the engine intake passage. What is necessary is just to adjust the amount of the combustion gas toward the intake passage.

If more combustion gas flows toward the upstream side of the catalyst in the engine exhaust passage, it is possible to activate the catalyst faster, and if not so, the catalyst in the engine exhaust passage is correspondingly activated. What is necessary is just to adjust the amount of the combustion gas toward the upstream side.

Therefore, by suitably adjusting the amount of the combustion gas flowing toward the engine intake passage and the catalyst, both the internal combustion engine and the catalyst can be heated by the combustion gas heat even after the cranking.

(2) When the internal combustion engine is in the predetermined stop state and needs to operate the combustion type heater, the start of the internal combustion engine is executed together with the combustion execution of the combustion type heater. In this case, it is desirable to operate a preheating plug provided in the engine combustion chamber as an auxiliary device for preventing heat loss.

Here, the "preheating plug" can be exemplified by a glow plug normally provided in a diesel engine or the like.
Since the ignition method of a diesel engine is based on the heat of compression of air, for example, when the shape of the combustion chamber is complicated, as in the case of a so-called vortex type, the rate of heat loss increases accordingly. . Therefore, a glow plug is used to assist ignition in the combustion chamber through electric current when starting the engine.

In the present invention, the preheating plug can also be operated when the combustion type heater is operated. Therefore, when the internal combustion engine starts cranking, the internal combustion engine adds to the heat amount of the combustion gas introduced into the engine intake passage, Since the heat of the preheating plug is also received, the degree of increase of the intake air temperature increases accordingly. Therefore, the ignition becomes easier, so that the engine startability is enhanced.

Note that, depending on the engine temperature, the intake air temperature may be increased only by the combustion heat of the combustion heater without operating the preheating plug. (3) A vehicle equipped with the internal combustion engine has a heating heat exchanger for heating the interior of the vehicle, and a cooling water flow through which the engine cooling water flows through the heating heat exchanger, the combustion heater, and the engine body. The combustion-type heater has a cooling water introduction passage for introducing engine cooling water therein and a heating unit for heating the cooling water in the cooling water introduction passage, and is heated by the heating unit. Circulated cooling water through the cooling water flow passage between the combustion heater, the engine body, and the heating heat exchanger, and when the internal combustion engine starts cranking, the heated cooling water is supplied to the engine. A circulating cooling water control means for circulating only between the main body and the combustion type heater to stop the flow of the cooling water to the heating heat exchanger;

Here, the "heating heat exchanger" can be exemplified by an indoor heating core of a vehicle equipped with an internal combustion engine. The “circulating cooling water control means” includes, for example, a valve device that is provided in the cooling water flow passage and shuts off the flow of the cooling water to the heating heat exchanger.

According to the present invention, during the execution of cranking, the heated cooling water is circulated only between the engine body and the combustion type heater, and the heated cooling water does not flow through the heating heat exchanger. For this reason, a large amount of the heated cooling water is supplied to the engine main body, so that the warming-up of the engine main body can be accelerated.

(4) After cranking and after starting the internal combustion engine, the combustion gas may be introduced into the catalyst through the combustion gas catalyst upstream introduction means.
By doing so, the catalyst warm-up can be further accelerated after the engine is started.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of an internal combustion engine having a combustion heater according to the present invention will be described below with reference to the accompanying drawings. <First Embodiment> A first embodiment will be described with reference to FIGS.

FIG. 1 schematically shows the entire structure of an internal combustion engine, for example, a diesel engine 1 (hereinafter referred to as "engine 1"). The diesel engine 1 is, for example, a direct combustion type without a glow plug because there is no auxiliary combustion chamber.

The engine 1 is provided with an engine body 3 as an engine body having a water jacket (not shown) containing engine cooling water, and air necessary for combustion in a combustion chamber in a plurality of cylinders (not shown) of the engine body 3. An intake device 5 to be supplied and air sent from the intake device 5 to the cylinder are mixed with engine fuel which is injected in a cylinder by a fuel injection valve (not shown) to form an air-fuel mixture. After the combustion in the formed combustion chamber, the exhaust device 7 discharges exhaust gas discharged from the cylinder into the atmosphere, the interior heating core 10 for heating the vehicle interior, and the combustion heater 17 attached to the engine 1. And an ECU 11 that is an engine control device that controls the entire engine.

Next, these members constituting the engine 1 will be described. The intake device 5 has an engine intake passage (hereinafter, referred to as “intake passage”) 14 that starts with an air cleaner 13 that filters outside air and ends with an intake port (not shown) of the engine body 3.

In the intake passage 14, between the air cleaner 13 and the intake port, an intake air temperature sensor 14a, a compressor 15a of a turbocharger 15, and a compressor 15a.
An intercooler and other intake system structures (not shown) for cooling the intake air heated by the compression heat generated when a is operated are disposed.

The exhaust device 7 has an engine exhaust passage (hereinafter referred to as "exhaust passage") 27 starting and ending with an exhaust port and a muffler (both not shown) of the engine body 3 respectively. In the exhaust passage 27, between the exhaust port and the muffler, a turbine 15b of the turbocharger 15, a catalytic converter 29 including an exhaust purification catalyst for purifying exhaust gas flowing through the exhaust passage 27, and other exhaust systems not shown. Structures are arranged. Since the main components of the catalytic converter 29 are an exhaust gas purifying catalyst, the catalytic converter and the exhaust gas purifying catalyst can be treated as synonyms.

The interior heating core 10 is connected to the water jacket of the engine body 3 via a water pipe W, and is a device for warming the vehicle interior mainly by using the engine cooling water heated in the water jacket as a heat source. Also,
The interior heating core 10 is also connected to the combustion type heater 17 via the water pipe W, and the interior of the vehicle is also heated by utilizing the combustion heat of the combustion type heater 17.

Then, the cooling water in the water pipe W is circulated by an engine water pump (not shown) (see a thin arrow in FIG. 1). Note that a water temperature sensor 3a is attached to the water jacket.

Therefore, the water pipe W is provided with the indoor heating core 10.
And the combustion type heater 17 and the engine body 3, and can be said to be a cooling water flow passage through which engine cooling water flows to these three members. The water pipe W has a forward pipe W1 flowing from the engine main body 3 to the interior heating core 10 and a return pipe W2 returning from the interior heating core 10 to the engine main body 3.

The cooling water that has passed through the indoor heating core 10 is:
The heat is exchanged there and the interior of the vehicle is warmed and cooled at the same time as it is heated.Then it returns to the water jacket and receives heat there.
Thereafter, as necessary, circulation involving heat exchange between the indoor heating core 10 and the water jacket is repeated. Therefore, it can be said that the indoor heating core 10 is a heating heat exchanger.

The combustion type heater 17 warms the engine cooling water by the combustion heat, and the warmed engine cooling water is sent to the water jacket of the engine body 3 and the interior heating core 10 to be heated. Raise the temperature of hot spots. Therefore, the combustion type heater 17 is attached to the water pipe W via the bridging pipe W3 and the bridging pipe W4 on the outward pipe W1 and the return pipe W2 of the water pipe W, respectively.

At the intersection B between the forward pipe W1 and the bridge pipe W3 and at the intersection C between the return pipe W2 and the bridge pipe W4, three-way valves 86B and 86C are attached, respectively.
As is well known, a three-way valve is a valve having a fluid inlet / outlet in three directions. The valves provided at intersections B and C are:
Not only the three-way valve but also an on-off valve for opening and closing the openings of the bridge pipes W3 and W4 may be used.

Further, the combustion type heater 17 converts the combustion gas discharged therefrom into the engine body 3 and the catalytic converter 2.
9 can also be warmed up (see bold arrows in FIG. 1).

That is, when the combustion gas warms up the engine body 3, the combustion gas discharged from the combustion heater 17 connects the combustion heater 17 with the intake passage 14 and guides the combustion gas to the intake passage 14. Is introduced into the intake passage 14 by the combustion gas intake passage side guide tube 32.

When the combustion gas warms up the catalytic converter 29, the combustion gas discharged from the combustion heater 17 connects the combustion heater 17 with the exhaust passage 27, and
The combustion gas discharged from 7 is introduced into the exhaust passage 27 by a combustion gas catalyst upstream guide pipe 34 which is a passage for guiding the combustion gas to a catalyst upstream portion U in the exhaust passage 27.

The combustion gas catalyst upstream guide tube 34 branches off in the middle of the combustion gas intake passage side guide tube 32, and a three-way valve 86A is installed at the branch point A. Here, the structure of the combustion heater 17 will be described in relation to the water pipe W, the bridge pipes W3, W4, etc., with reference to FIG.

The combustion type heater 17 has therein a heater internal cooling water passage 17a as a cooling water introduction passage for introducing cooling water from the water jacket from the intersection B via the bridging pipe W3.

The cooling water passage 17a inside the heater is
The cooling water inlet 17a1 connected to the outgoing pipe W1 at the intersection B via the bridging pipe W3, and the cooling water discharge port 17a2 also connected to the return pipe W2 at the crossing C via the bridging pipe W4. Have.

Therefore, the combustion type heater 17 can circulate the cooling water between the water jacket of the engine body 3 and the room heating core 10. The cooling water (indicated by a dashed arrow in FIG. 2) flowing through the heater internal cooling water passage 17a passes around a combustion chamber 17d which is a combustion part formed inside the combustion type heater 17, and passes therethrough. The heat is received by the heat from the combustion chamber 17d. That is,
The combustion chamber 17d can be said to be a heating unit for heating the cooling water in the cooling water passage 17a inside the heater.

The combustion chamber 17d has a combustion tube 17b as a combustion source for emitting a flame, a cylindrical partition wall 17c for covering the combustion tube 17b to prevent the flame from leaking outside, and an ignition (not shown) for detecting the presence or absence of ignition. It has a sensor and the like.

By covering the combustion cylinder 17b with a partition wall 17c,
A combustion chamber 17d is defined inside the partition 17c. The partition 17c is also covered by the outer wall 43 of the combustion type heater 17, and a space is provided between the two. By providing this space, the above-described heater internal cooling water passage 17a is formed between the inner surface of the outer wall 43 and the outer surface of the partition wall 17c.

The combustion chamber 17d is provided with an air supply port 1 communicating with the atmosphere and the combustion gas intake passage side guide tube 32, respectively.
7d1 and an exhaust outlet 17d2. The air a1 flowing from the atmosphere enters the combustion chamber 17d from the air supply port 17d1 and travels through the inside thereof to become the combustion gas a2 while reaching the exhaust discharge port 17d2.
Flows into the combustion gas intake passage side guide tube 32.

The driving force for positively flowing the combustion gas is a blowing fan 45 provided at one end of the combustion heater 17.
It is. The blower fan 45 outputs the flame F of the combustion cylinder 17b.
And a motor 45a as a drive unit and a fan 4 that is rotated by the motor 45a.
5b.

The combustion gas that has flowed into the combustion gas intake side guide tube 32 in response to the wind force of the blower fan 45 is branched at the branch point A into the combustion gas catalyst upstream guide tube 34 by the three-way valve 86A, and this combustion gas catalyst upstream. Either guided by the guide tube 34 and proceeding to the exhaust side, or by a three-way valve 86A installed at a branch point A in the middle of the combustion gas intake side guide tube 32,
The course is determined so as to proceed along the combustion gas intake side guide tube 32 as it is and proceed to the intake side, or to proceed to both the combustion gas intake side guide tube 32 and the combustion gas catalyst upstream guide tube 34.

For example, when the engine 1 is in a stopped state in which cranking has not yet been performed and the driver operates the ignition switch IG, whereby the combustion type heater 17 is in an operable state (the engine 1 is brought into such a state).
The case where there is is referred to as "the engine 1 is in a predetermined stop state". ) And when the temperature is so cold that the combustion type heater 17 needs to be operated, the three-way valve 86A at the branch point A is controlled by the ECU 11, and as a result, the three-way valve 86A is discharged from the combustion type heater 17. The combustion gas is introduced through a combustion gas catalyst upstream guide pipe 34 toward a location U in the engine exhaust passage 27 upstream of a location where the catalytic converter 29 is installed. Therefore, the combustion gas catalyst upstream guide pipe 34, the three-way valve 86A, the ECU 11
This is referred to as a combustion gas catalyst upstream introduction means.

The cranking means that the engine body 3
The crankshaft is rotated by an engine start assisting means such as a starter motor (not shown) attached to the engine, and the crankshaft (not shown) is rotated by the reciprocating motion of the piston obtained during the explosion stroke in the operation stroke of the engine 1. Distinguish from starting the engine, which means that it starts moving.

The condition for executing the operation of the combustion heater is satisfied when it is necessary to promote the warm-up by the heat of the combustion gas of the combustion heater, for example, at a time of cold enough to operate the combustion heater 17. I do.

When cranking is started, the three-way valve 86A at the branch point A is controlled by the ECU 11 to reduce or stop the introduction of the combustion gas to the upstream side of the catalyst, which has been performed so far. A part or all of the flow of the combustion gas is changed to the engine intake side. At least a portion of the combustion gas whose flow direction has been changed to the engine intake side is guided by the combustion gas intake passage side guide tube 32. Therefore, the combustion gas intake passage side guide tube 32 and the three-way valve 86A
The ECU 11 is referred to as combustion gas intake side guide means.

In addition, according to the operating state of the engine 1,
When both engine warm-up and catalyst warm-up are required, the three-way valve 86A
Is controlled by the ECU 11 so that the combustion gas intake passage side guide pipe 32 and the combustion gas catalyst upstream guide pipe 3
4 to allow the combustion gas to flow.

On the other hand, until the combustion gas is exhausted from the combustion type heater 17, the combustion heat of the combustion gas is transmitted to the cooling water flowing through the heater internal cooling water passage 17a through the partition wall 17c and cooled as described above. Warm the water. Accordingly, the combustion chamber 17d is provided with a heat transfer passage that heats the heat of the combustion gas flowing out of the combustion chamber 17d of the combustion type heater 17 to the cooling water and warms the cooling water flowing through the heater internal cooling water passage 17a. Department.

The combustion cylinder 17b is connected to a fuel supply pipe 17e.
And receives, for example, light oil, which is the same fuel as the engine combustion fuel, by receiving a pump pressure of a fuel pump (not shown).
To supply. The supplied combustion fuel is supplied to the combustion heater 1
The fuel is vaporized by a wick, which is a fuel evaporator in the fuel cell 7, and turns into vaporized fuel. It is ignited by the rising glow plug.

The amount of fuel supplied through the fuel supply pipe 17e varies according to the operating state of the combustion heater 17. The fuel supply pipe 17e communicates with the fuel injection valve of the engine 1 (see a dashed arrow in FIG. 1 and FIG. 2).

When the ignition switch is turned on, the glow plug is energized and generates heat. When the engine 1 is in the predetermined stop state and the combustion type heater 17
When it is necessary to operate the glow plug, the glow plug is operated to assist the catalyst warm-up even during the combustion by the combustion type heater 17.

However, since it is meaningless to generate heat by the glow plug until the intake air temperature or the temperature of the cooling water exceeds a certain temperature, the temperature of the cooling water in the water jacket detected by the water temperature sensor 3a is exemplified. Typically 0
When the temperature is higher than ° C., the glow plug does not generate heat.

The point is that when the intake air temperature or the cooling water temperature is too low, the heat generated by the glow plug is added to the combustion heat of the combustion type heater 17. By the way, if the intake air temperature and the cooling water temperature are low, the combustion chamber 17d will not be warmed up unless the energizing time to the glow plug is lengthened, so that it is difficult to ignite and it is difficult to generate a fire. For this reason, it takes time to realize the combustion by the combustion type heater 17. However, if the intake air temperature or the cooling water temperature is high, combustion by the combustion type heater 17 is realized even if the time for energizing the glow plug is short.

Therefore, using a map M as shown in FIG. 3, the preheating time required by the glow plug to bring the inside of the combustion chamber 17d to a temperature suitable for ignition is obtained based on, for example, the engine cooling water temperature. It is preferable to warm the combustion chamber 17d in advance before combustion based on the preheating time, because the rise time until combustion is shortened. The preheating time may be obtained from the intake air temperature, or may be obtained from both the intake air temperature and the cooling water temperature. Further, the temperature suitable for the ignition of the combustion chamber 17d means at least a normal temperature at which light oil of the fuel used in this embodiment can be easily ignited.

Since the required preheating time varies depending on the temperature of the engine cooling water, the required preheating time is referred to as a predetermined preheating time determined based on the temperature of the engine cooling water before energizing the glow plug (hereinafter, referred to as “preheating time”). This is abbreviated as “predetermined preheating time”.)

That is, the map M is a predetermined preheating time-engine cooling water temperature diagram in which the vertical axis indicates the predetermined preheating time and the horizontal axis indicates the engine cooling water temperature. In the map M, for example, when the engine cooling water temperature is a, if the predetermined preheating time is set to a 'and preheating is performed, the temperature in the combustion chamber 17d can be set to the suitable temperature for performing ignition. Means

As can be seen from the map M, when the engine coolant temperature is high, the preheating time is short, and when the engine cooling water temperature is low, it is necessary to increase the preheating time. Now return to FIG.

The water pipe W is provided with an electric water pump 33 which can be operated even when the engine is stopped. The electric water pump 33 operates by turning on the ignition switch even when the engine is stopped. Therefore, when the engine is stopped, the combustion type heater 1
When the engine 7 is operated, warm cooling water circulates in the water pipe W even when the engine is stopped, so that the indoor heating core 10 functions effectively. In addition, the catalyst can be warmed up.

Conversely, when the electric water pump 33 is operated while the engine 1 is operating, the amount of cooling water circulating in the water pipe W pumped by the engine water pump increases.

The ECU 11 includes a central processing control unit CPU, which is interconnected by a bidirectional bus (not shown).
Read only memory ROM, random access memory R
It comprises an AM, an input interface circuit, an output interface circuit and the like.

The input interface circuit is electrically connected to various sensors, and when output signals of these various sensors enter the ECU 11 from the input interface circuit, these parameters are temporarily stored in the random access memory RAM. You.

Then, when the CPU performs necessary arithmetic processing based on these parameters, the CPU calls the parameters stored in the random access memory RAM through the bidirectional bus as necessary,
Various devices connected to the output interface circuit are appropriately operated based on the result of the calculation performed by the CPU.

As sensors connected to the input interface circuit, in addition to the above-mentioned water temperature sensor 3a, intake temperature sensor 14a, ignition sensor and ignition switch, an air flow meter (not shown) attached to the intake passage 14 and a catalytic converter 29 are provided. Examples include a catalyst sensor attached, an accelerator position sensor attached to an accelerator pedal or an accelerator lever that operates in conjunction with the accelerator pedal, a starter switch, and the like. These sensors output an electrical signal corresponding to the detected value and send it to the input interface circuit.

The parameters of the water temperature sensor and other various sensors are stored in the random access memory RA of the ECU 11.
M is temporarily stored in M and is called up as needed. The map M is a read-only memory ROM.
Which is also called up as needed.

The output interface circuit operates based on the output signals of the various sensors, and operates as described above for the fuel injection valve, the combustion heater 17, the electric water pump 33,
It is electrically connected to various devices such as the blower fan 45, the three-way valves 86A, 86B, 86C, the glow plug, and the fuel pump, and controls the operation of these devices.

Next, a program for realizing an operation control execution routine of the engine 1 by the ECU 11 will be described with reference to flowcharts of FIGS. FIG.
5 and FIG. 5, which should be collectively shown on the same paper, are separated by the space of the paper. The symbols (1) to (3) shown in FIG. 4 and the symbols (1) to (3) shown in FIG.
Guides the destination of the process.

For example, (1) in FIG. 4 corresponds to (1) in FIG. 5, and the processing in the route according to (1) in FIG. 4 shifts to the route according to (1) in FIG. It means to continue in FIG. This description also applies to FIGS. 6 and 7 described later.

This program includes a plurality of steps starting from step 101 described below. The program including these steps is executed by the RO of the ECU 11.
It is stored in M and is called up as needed. All the processes in the above steps are performed by the CPU of the ECU 11. Note that the symbol S is used, and for example, if it is step 101, it is abbreviated as S101.

In step S101, the ignition switch IG
It is determined whether or not the operation execution condition of the combustion type heater 17 is satisfied, such as when the output signal value is ON and the engine 1 is in a cold state.

If an affirmative determination is made in S101, the next S1
The routine proceeds to step 02, and if a negative determination is made, the routine ends. In S102, it is determined whether or not the ignition switch has just been turned ON. The reason immediately after is to determine whether or not the engine 1 is started. This is because the object of the present invention is to enable sufficient exhaust gas purification even immediately after the start of the engine.

If an affirmative determination is made in S102, the process proceeds to S103, and if a negative determination is made, the process proceeds to S105. In S103, the intake air temperature and the coolant temperature before the glow plug is energized by the combustion heater 17 are read from the intake air temperature sensor 14a and the water temperature sensor 3a, respectively.

In S104, it is determined whether or not the output signal value THW (cooling water temperature) of the water temperature sensor 3a obtained in S103 is lower than a predetermined temperature. Here, the predetermined temperature is
In performing the combustion of the combustion type heater 17, the temperature value is a reference value for determining whether or not the preheating by the glow plug is necessary, for example, 0 ° C. If an affirmative determination is made in S104, preheating is necessary, and in that case, S1
Go to 05. When a negative determination is made, it means that preheating is not required, and in that case, the process proceeds to S109.

In S105, based on the cooling water temperature (temperature value a in the case of FIG. 3 described above) obtained in S103,
A predetermined preheating time (predetermined preheating time a ′ in FIG. 3) is obtained from the map M.

In S106, energization of the glow plug is started with the predetermined preheating time a 'as a target, and the combustion chamber 1
The temperature within 7d is raised in advance. Predetermined preheating time a '
Starting the energization of the glow plug with the goal of is referred to as the start of glow control of the combustion heater 17 for convenience.

In S107, it is determined whether or not the predetermined preheating time a 'has actually elapsed from the start of energization of the glow plug. If an affirmative determination is made in S107, the process proceeds to S109, and if a negative determination is made, this routine ends.

In S109, it is determined whether or not the intake air temperature obtained in S103 is lower than a predetermined temperature. Here, the predetermined temperature is a temperature value serving as a criterion for determining whether or not to operate the combustion-type heater 17, for example, 0 ° C.

If an affirmative determination is made in S109, the process proceeds to S110, and if a negative determination is made, the process proceeds to S111 and the combustion type heater 17
Is executed, and then this routine is terminated.
This is because the engine is operating at a high engine temperature without operating the combustion heater 17 and utilizing the combustion heat.

At S110, an ignition control for causing the combustion type heater 17 to start a fire is executed. At this time, the number of rotations of the fan and the amount of fuel supplied to the combustion type heater 17 depend on the combustion type heater 1.
Since it is enough to ignite 7, the value is smaller than those values required when a fire is grown into a flame.

In step S112, the combustion of the combustion type heater 17 is executed by securing the number of rotations of the fan and the amount of fuel supplied to the combustion type heater 17 necessary for growing a fire into a flame. After performing the ignition control in S110, the combustion type heater 17
It is necessary to perform a process of determining whether or not the ignition is actually performed by an ignition sensor, but the description is omitted to avoid complicating the description because it is not directly related to the present invention, and the ignition is performed. Is assumed.

In S113, it is determined whether or not the starter motor is operating (starter switch ON), in other words, whether or not cranking is being performed. S113
If a negative determination is made in S11, it is determined that the engine 1 is in a non-cranking state in which cranking is not performed, and S11 is performed.
If the determination is affirmative, the process proceeds to S115 on the assumption that the engine 1 is in a state where cranking is being performed.

At S114, which proceeds when the engine 1 is in the non-cranking state, at the combustion gas catalyst upstream guide pipe 34
The three-way valve 86A at the branch point A is controlled so that the combustion gas flows into only the combustion gas and the combustion gas does not flow into the combustion gas intake passage side guide tube 32.

At the same time, the cooling water passage 17a inside the heater of the combustion type heater 17
The three-way valves 86B and 86C at the intersections B and C prevent the cooling water from circulating between the water jacket and the water jacket, that is, prevent the cooling water from flowing through the bridge pipes W3 and W4.
Control. When the cooling water is heated, the amount of heat of the combustion type heater 17 is deprived accordingly, so that this is avoided. By doing so, the high heat generated from the flame of the combustion type heater 17 directly reaches the catalytic converter 29, so that the activation of the catalyst can be further promoted.

Next, in S115, which proceeds during the cranking operation including the case where the engine 1 starts cranking,
The introduction of the combustion gas to the combustion gas catalyst upstream guide pipe 34 is reduced or stopped, thereby changing a part or all of the flow of the combustion gas to the engine intake side.

This change is performed by controlling the three-way valve 86A disposed at the branch point A. When a part of the combustion gas flows to the engine intake side, part of the combustion heat of the combustion type heater 17 is connected to the combustion gas intake passage side guide pipe 3 connected to the intake passage 14.
The remaining combustion gas that has been introduced into the cylinder via the engine 2 and has not flowed to the engine intake side flows through the combustion gas catalyst upstream guide pipe 34 to the upstream side of the catalyst 29.

At the same time, the internal cooling water passage 17a of the heater 17
The three-way valves 86B and 86C at the intersections B and C are controlled so that the heated cooling water circulates only between the water heater and the water jacket. And W4, but the flow of the cooling water to the indoor heating core 10 is stopped. Therefore, the three-way valves 86B, 8 at the intersections B and C
6C, when the engine 1 starts cranking, the heated cooling water is supplied to the engine body 3 and the combustion heater 17.
This is called a circulating cooling water control unit that circulates only between the above and the cooling water to the indoor heating core 10 to stop the flow.

In step S116, the engine 1 is ignited while executing the injection control of the engine fuel injected from the injector into the combustion chamber of the engine 1, and the engine 1 is started. In practice, it is necessary to determine whether or not the engine 1 has started. However, since the engine is sufficiently warmed up in S115, it is assumed that the engine 1 is started and the description is omitted.

S117 is a control after the engine 1 is started, and when the cooling water temperature becomes sufficient to warm up the engine,
The flow of the combustion gas into the combustion gas catalyst upstream guide pipe 34 is executed again, the flow direction of the combustion gas is changed to the upstream side of the catalyst, and the combustion gas whose flow direction has been changed is discharged into the exhaust passage 2.
The three-way valve 86A at the branch point A is controlled so that it can be guided to the upstream portion U of the catalyst.

At the same time, the three-way valves 86B at the intersections B and C,
86C is controlled so that the cooling water after warm-up flows to the indoor heating core 10. In other words, after the cranking and after the engine 1 is started, it can be said that the combustion gas is introduced into the catalyst via the combustion gas catalyst upstream guide pipe 34 constituting the combustion gas catalyst upstream introduction means.

The engine 1 is in a completely stopped state in which the engine 1 has not yet been cranked, and the ignition switch is operated by the driver. As a result, the combustion type heater 17 is in an operable state, and the engine 1 cools down in cold weather. Therefore, when there is a request for operation of the combustion type heater 17, the combustion gas of the combustion type heater 17 is supplied to the exhaust passage 27 upstream of the installation position of the catalytic converter 29 containing the exhaust purification catalyst. It is introduced to a nearby location U. Therefore, the catalyst can be activated before the engine is started.

For this reason, if the combustion temperature of the combustion type heater 17 is adjusted by adjusting the output of the combustion type heater 17 and the catalyst is already sufficiently activated at the start of the engine 1, the engine 1 Sufficient exhaust gas purification can be performed even immediately after starting.

When the cranking is started, the introduction of the combustion gas to the upstream side of the catalyst is reduced or stopped, and a part or all of the flow of the combustion gas is guided toward the intake passage 14. When a part of the combustion gas flows to the engine intake side, a part of the combustion heat of the combustion type heater 17 is introduced into the cylinder via the combustion gas intake passage side guide pipe 32 and does not flow to the engine intake side. The remaining combustion gas flows upstream of the catalyst 29 via a combustion gas catalyst upstream guide pipe 34. For this reason, the catalyst temperature is also increased by the combustion heat of the remaining combustion gas.

Therefore, when it is desired to increase the promotion amount of the engine warm-up, more combustion gas is supplied to the combustion gas intake passage side guide pipe 3.
2, the engine can be warmed up faster, and if not so, the amount of combustion gas flowing toward the combustion gas intake passage side guide tube 32 may be adjusted accordingly.

Further, more combustion gas is supplied to the exhaust passage 27.
The catalyst can be activated more quickly if it flows toward the upstream of the catalyst. If not so, the amount of combustion gas flowing toward the upstream of the catalyst in the exhaust passage 27 may be adjusted accordingly.

Therefore, the combustion gas intake passage side guide tube 3
By suitably adjusting the amount of combustion gas flowing toward the catalyst converter 2 and the catalytic converter 29, both the engine body 3 and the catalyst 29 can be kept warm by combustion gas heat even after cranking.

In addition, during execution of cranking, the heated cooling water is circulated only between the engine body 3 and the combustion heater 17, and the heated cooling water does not flow through the interior heating core 10. For this reason, a large amount of heated cooling water is supplied to the engine main body 3 so that warm-up of the engine main body 3 can be accelerated.

Furthermore, after cranking, the engine 1
Is started, the three-way valve 86A is controlled by the ECU 11
To change the flow of the combustion gas to the exhaust passage 27 side, and then introduce the combustion gas to the catalyst of the catalytic converter 29 through the combustion gas catalyst upstream guide pipe 34.

By doing so, the catalyst warm-up can be further accelerated after the engine is started. <Second Embodiment> A second embodiment will be described with reference to FIGS.

The second embodiment is different from the first embodiment in that a well-known combustion chamber, for example, of a pre-combustion chamber type or a vortex-type combustion chamber is employed in the engine, and the combustion chamber is used for starting the engine. A preheating plug (not shown) that assists ignition in the combustion chamber and thus functions as an auxiliary device for preventing heat loss
The present invention is applied to a diesel engine having

Therefore, only the differences will be described, and the overall configuration of the engine and the configuration of the combustion heater will be described in the first.
Please refer to FIG. In the engine according to the second embodiment, when the ignition switch IG is turned on, a current flows through the preheating plug to generate heat.

When the preheating by the preheating plug is completed, a notification lamp (not shown) attached to the cockpit is turned on to notify the driver of this. Therefore, this lamp is referred to as a preheating time elapsed notification lamp. Preheating completion is determined by whether a predetermined time has elapsed after the start of preheating. The preheating time is obtained from a well-known preheating time intellectual map (not shown).

Next, a program for implementing an operation control execution routine of the engine 1 with the preheating plug by the ECU 11 will be described with reference to flowcharts of FIGS.

This program differs from the flowcharts of the routines shown in FIGS. 4 and 5 only in that S112A and S112B after S112 are added. Therefore, only the different steps will be described. Please refer to the description of the first embodiment.

At S112A, which proceeds after the process of S112, that is, after the combustion of the combustion type heater 17, the preheating time of the preheating plug is determined from the preheating time information map. If a positive determination is made in S112A, S112
Proceeding to B, this routine ends if a negative determination is made.

At S112B, the preheating time elapsed notification lamp is turned on. After S112B, the process proceeds to S113. As described above, in the engine having the preheating plug, S11
When the starter switch is turned on at 3 to start cranking, and when the combustion gas of the combustion type heater 17 is guided to the intake passage 14 by the combustion gas intake side guide means, the preheating plug has already been activated. Therefore, the combustion type heater 1
Both the combustion heat of 7 and the heat generated by the preheating plug further increase the degree of increase in the intake air temperature. Therefore, engine 1
However, it becomes easier to ignite, so that the engine startability is improved.

[0115]

As described above, according to the engine having the combustion type heater of the present invention, sufficient exhaust gas purification can be performed even immediately after the start of the internal combustion engine. Further, the ignition becomes easy, so that the engine startability is enhanced.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing an operation state of the combustion type heater.

FIG. 3 is a predetermined preheating time-engine cooling water temperature diagram.

FIG. 4 is a part of a flowchart showing an operation control execution routine of an engine having no preheating plug;

FIG. 5 is a part of a flowchart continuing from FIG. 4;

FIG. 6 is a part of a flowchart showing an operation control execution routine of an engine having a preheating plug;

FIG. 7 is a part of a flowchart following FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Diesel engine (internal combustion engine) 3 Engine main body (engine main body) 3a Water temperature sensor 5 Intake device 7 Exhaust device 10 Interior heating core (heating heat exchanger) 11 ECU (composition element of combustion gas catalyst upstream introduction means, combustion) 13 Air cleaner 14 Intake passage 14a Intake air temperature sensor 15 Turbocharger 15a Compressor 15b Turbine 17 Combustion heater 17a Heater internal cooling water passage (cooling water introduction passage) 17b Combustion cylinder 17c Partition wall 17d Combustion chamber (components of means) Heating part) 17d1 Air supply port 17d2 Exhaust exhaust port 17e Fuel supply pipe 27 Exhaust passage 29 Catalytic converter (exhaust purification catalyst) 32 Combustion gas intake passage side guide pipe (component of combustion gas intake side guide means) 33 Electric water pump 34 Combustion gas catalyst upstream guide pipe (combustion gas 43 Combustion chamber main body 43a Outer wall 45 Blower fan 45a Motor 45b fan 86A Three-way valve at branch point A (components of combustion gas catalyst upstream introduction means, components of combustion gas intake side guide means) 86B Circulating cooling water control means 86C Circulating cooling water control means A Junction point B Intersection point between forward pipe W1 and bridge pipe W3 Intersection point between return pipe W2 and bridge pipe W4 U Upstream from the installation location M map W Water pipe (cooling water flow passage) W1 Outgoing pipe W2 Incoming pipe W3 Bridge pipe W4 Bridge pipe a Engine cooling water temperature a 'Predetermined preheating time a1 Air a2 Combustion gas

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F01N 5/02 F01N 5/02 H A K 9/00 9/00 Z F01P 3/20 F01P 3/20 H E 7/16 504 7/16 504C 504E F02D 21/06 F02D 21/06 41/02 301 41/02 301E 45/00 310 45/00 310B (72) Inventor Taiichi Mori 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Co., Ltd. (72) Inventor Masanao Koie 2-1-1 Toyota-machi, Kariya-shi, Aichi F-term in Toyota Industries Corporation (reference) 3G084 BA00 BA20 BA24 BA26 BA28 BA29 CA01 DA10 EA07 EA11 EC01 FA02 FA20 FA35 FA36 3G091 AA02 AA10 AA18 AB01 BA03 CA02 CA12 CA13 CB05 CB08 DB10 EA05 EA07 EA15 EA16 EA26 EA28 FA02 FA04 FA12 FA13 FB02 FB10 FC05 FC07 HB03 HB06 3G092 AA02 AA06 AA18 AB20 DC00 DE18S DF02 EA28 EA29 FA15 FA31 FA42 GA01 HA04Z HC02Z HD02X HE08Z HF19Z 3G301 JA21 KA01 LA00 NE17 NE23 PA10Z PE08Z PE09Z PF16Z

Claims (4)

[Claims] A combustion heater attached to an internal combustion engine; an exhaust gas purification catalyst installed in an engine exhaust passage for purifying exhaust gas flowing through the engine exhaust passage; A combustion gas catalyst upstream introduction means for introducing combustion gas discharged from the combustion heater when it is necessary to operate the combustion heater to a portion of the engine exhaust passage upstream of a location where the exhaust purification catalyst is installed. When the internal combustion engine starts cranking, the introduction of the combustion gas to the upstream side of the catalyst by the combustion gas catalyst upstream side introduction means is reduced or stopped, and part or all of the flow of the combustion gas is changed to the engine intake side, An internal combustion engine having a combustion type heater having: a combustion gas intake side guide means for guiding at least a part of the combustion gas whose flow direction has been changed to the engine intake side into the engine intake passage. 2. When the internal combustion engine is in the predetermined stop state and it is necessary to operate the combustion type heater, it is used together with execution of combustion of the combustion type heater to execute heat when starting the internal combustion engine. 2. An internal combustion engine having a combustion heater according to claim 1, wherein a preheating plug provided in the engine combustion chamber is operated as an auxiliary device for preventing loss. 3. A vehicle equipped with the internal combustion engine has a heating heat exchanger for heating the interior of the vehicle, and engine cooling water flows through the heating heat exchanger, the combustion heater and the engine body. The combustion type heater has a cooling water introduction passage for introducing engine cooling water therein, and a heating unit for heating the cooling water in the cooling water introduction passage. The heated cooling water is circulated between the combustion heater, the engine body, and the heating heat exchanger through the cooling water flow passage, and when the internal combustion engine starts cranking, the heated cooling water is discharged. 3. A circulating cooling water control unit that circulates only between the engine body and the combustion type heater to stop the flow of the cooling water to the heating heat exchanger. Has a combustion heater Internal combustion engine. 4. The combustion gas is introduced into the catalyst through the combustion gas catalyst upstream introduction means after the internal combustion engine is started after cranking.
An internal combustion engine having the combustion heater according to any one of claims 1 to 3.