JP2003343368A - Internal combustion engine having a combustion heater - Google Patents

Abstract

(57) Abstract: An object of the present invention is to improve the startability and fuel consumption rate of an internal combustion engine having a combustion type heater by providing a technology capable of reducing the friction of the internal combustion engine in the internal combustion engine. The task is to make SOLUTION: The present invention relates to an internal combustion engine provided with a combustion type heater that burns fuel independently of the internal combustion engine, and before starting the internal combustion engine, the combustion gas of the combustion type heater is blown by the existing blow-by gas recirculation in the internal combustion engine. By introducing into the passage,
It is characterized in that the internal combustion engine body is directly heated, thereby reducing the friction of the internal combustion engine at the time of starting and after starting.

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 mounted on a vehicle or the like, and more particularly to an internal combustion engine equipped with a combustion heater that burns fuel independently of the internal combustion engine.

[0002]

2. Description of the Related Art In recent years, there has been developed an internal combustion engine equipped with a combustion heater that burns fuel independently of the internal combustion engine for the purpose of early warm-up of the internal combustion engine in a cold state and improvement of indoor heating performance. It is being advanced.

As an internal combustion engine having such a combustion type heater, for example, an internal combustion engine having a combustion type heater as described in JP-A-11-229978 is known.

The internal combustion engine having the combustion type heater described in this publication introduces high temperature combustion gas discharged from the combustion type heater into the intake passage of the internal combustion engine when the internal combustion engine is in a cold state. This is intended to raise the intake air temperature of the internal combustion engine.

[0005]

By the way, when the internal combustion engine is in a cold state, the oil clearance of the crank journal, the camshaft journal, etc. becomes narrower than an appropriate value and the viscosity of the lubricating oil (engine oil) becomes high. Therefore, the friction of the internal combustion engine increases, and the startability and the fuel consumption rate tend to deteriorate.

However, in the above-mentioned conventional technique,
When the internal combustion engine is cold, the combustion gas from the combustion heater is mixed into the intake air of the internal combustion engine, so it is possible to raise the intake air temperature, but it is difficult to warm the internal combustion engine body and lubricating oil. Therefore, it may be difficult to effectively improve the startability and the fuel consumption rate of the internal combustion engine.

The present invention has been made in view of the above-mentioned problems, and in an internal combustion engine having a combustion heater, by providing a technique capable of reducing the friction of the internal combustion engine, the internal combustion engine is provided. The purpose is to improve the startability and fuel consumption rate of the vehicle.

[0008]

The present invention adopts the following means in order to solve the above problems.
That is, an internal combustion engine having a combustion heater according to the present invention, a blow-by gas recirculation passage formed in the internal combustion engine,
A combustion heater that burns fuel independently of the internal combustion engine,
Supply means for supplying the combustion gas discharged from the combustion type heater to the blow-by gas passage before starting the internal combustion engine.

According to the present invention, in an internal combustion engine provided with a combustion type heater that burns fuel independently of the internal combustion engine, the combustion gas of the combustion type heater is blow-by gas recirculation passage existing in the internal combustion engine before the internal combustion engine is started. By introducing
The greatest feature is that the internal combustion engine body is directly heated.

In an internal combustion engine having such a combustion heater,
The supply means actuates the combustion heater and introduces the high-temperature combustion gas discharged from the combustion heater into the blow-by gas recirculation passage of the internal combustion engine before starting the internal combustion engine.

In this case, the high temperature combustion gas discharged from the combustion heater flows through the blow-by gas recirculation passage of the internal combustion engine, and the heat of the combustion gas is directly transferred to the internal combustion engine body.

As a result, the temperature of the internal combustion engine body is rapidly raised, and the oil clearances of the crank journal, the camshaft journal, etc. are expanded appropriately.

In the internal combustion engine having the combustion heater according to the present invention, when the blow-by gas passage is a passage from the crankcase of the internal combustion engine to the intake passage of the internal combustion engine through the cylinder block and the cylinder head in sequence. The supply means may supply the combustion gas of the combustion heater to the crankcase before starting the internal combustion engine.

In this case, the cylinder block and the cylinder head of the internal combustion engine are warmed by the heat of the combustion gas, and the lubricating oil stored in the oil pan in the crankcase is warmed, so that the cylinder block and the cylinder head are heated. And the temperature of the lubricating oil also rises rapidly.

As a result, the oil clearances of the crank journal and camshaft journal of the internal combustion engine are appropriately expanded, the viscosity of the lubricating oil is also reduced, and the drive loss of the oil pump and the like is also reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of an internal combustion engine having a combustion heater according to the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic structure of an internal combustion engine to which the present invention is applied. The internal combustion engine 1 shown in FIG. 1 is a four-stroke cycle internal combustion engine. This internal combustion engine 1
Is a cylinder block 1a in which the cylinder 100 is formed,
A cylinder head 1b fixed to the upper part of the cylinder block 1a is provided.

A piston 2 is reciprocally mounted in the cylinder 100 of the cylinder block 1a. A crankcase 1c is provided below the cylinder block 1a, and a crankshaft 3 as an engine output shaft is rotatably supported in the crankcase 1c.

The lower surface of the crankcase 1c is covered with an oil pan 1d, and the oil pan 1d is covered with the oil pan 1d.
The engine oil is stored as a lubricating oil of the internal combustion engine 1.

The piston 2 is connected to the crankshaft 3 via a connecting rod 4, and the reciprocating motion of the piston 2 is converted into the rotary motion of the crankshaft 3.

Above the piston 2, the piston 2
A combustion chamber 5 surrounded by the top surface of the cylinder head 1b, the wall surface of the cylinder head 1b, and the wall surface of the cylinder 100 is formed.

An intake port 6 is formed in the cylinder head 1b from an opening provided in one side wall of the cylinder head 1b to the combustion chamber 5, and the other side wall of the cylinder head 1b is formed. An exhaust port 7 is formed from an opening provided in the above to the combustion chamber 5.

The cylinder head 1b is provided with an intake valve 7 for opening and closing the intake port 6 and an exhaust valve 8 for opening and closing the exhaust port 7, and these intake valve 7 and exhaust valve 8 are connected. An intake camshaft 70 and an exhaust camshaft 80 that are driven to open and close are rotatably supported.

A cylinder head cover 1e for covering the valve operating mechanism as described above is attached to the upper part of the cylinder head 1b.

An intake pipe 9 communicating with the intake port 6 is connected to one side wall of the cylinder head 1b, and an exhaust pipe communicating with the exhaust port 7 is connected to the other side wall of the cylinder head 1b. 10 are connected.

The intake pipe 9 is an air cleaner box 1
Connected to 1. A throttle valve 12 for adjusting the amount of intake air flowing through the intake pipe 9 is provided in the middle of the intake pipe 9. On the other hand, the exhaust pipe 10 is connected downstream to a silencer via an exhaust purification catalyst (not shown).

In the internal combustion engine 1 thus constructed, the unburned gas component (blow-by gas) blown out from the combustion chamber 5 to the first space 50 in the crankcase 1c during the compression stroke and the expansion stroke. A PCV (Positive Crankcase Ventilation) system for scavenging air from the first space 50 is provided.

The PCV system includes a blow-by gas passage 60 extending from the first space 50 in the crankcase 1c to the second space 51 in the head cover 1c via the cylinder block 1a and the cylinder head 1b, and the second space. First from the space 51 to the intake pipe 9 upstream of the throttle valve 12
In the first space portion 50 provided in the middle of the second return passage 62 and the second return passage 62 extending from the second space 51 to the intake pipe 9 downstream of the throttle valve 12. The PCV valve 63 is opened only when the pressure becomes higher than the pressure in the intake pipe 9 downstream of the throttle valve 12.

In the PCV system configured as described above, when the internal combustion engine 1 is in a low load operating state (operating state in which the opening of the throttle valve 12 is small), the combustion chamber 5 moves to the first space 50. The amount of blow-by gas blown through decreases, and accordingly, the amount of blow-by gas guided from the first air space 50 to the second space 51 also decreases.
For this reason, the pressure in the second space 51 becomes relatively low, but since the intake pipe negative pressure is generated in the intake pipe 9 downstream of the throttle valve 12, the pressure in the second space 51 is reduced. It becomes higher than the pressure in the downstream intake pipe 9.

In this case, the PCV valve 63 is opened to connect the intake pipe 9 downstream of the throttle valve 12 and the second space 51. Then, the blow-by gas in the second space 51 is sucked into the intake pipe 9 downstream of the throttle valve 12. From the second space 51 to the throttle valve 12
The blow-by gas sucked into the intake pipe 9 on the downstream side is sucked into the internal combustion engine 1 and re-combusted together with the fresh air flowing from the upstream side of the throttle valve 12.

Further, when the negative pressure in the second space 51 becomes negative due to the negative pressure of the intake pipe generated in the intake pipe 9 downstream of the throttle valve 12 being applied to the second space 51, The blow-by gas in the space 50 is sucked into the second space 51, and the fresh air flowing in the intake pipe 9 upstream of the throttle valve 12 enters the second space 51 via the first recirculation passage 61. Will be sucked in.

As a result, the blow-by gas in the first space 50 is scavenged and at the same time the blow-by gas in the second space 51 is ventilated by fresh air.

On the other hand, when the internal combustion engine 1 is in a high load operating state (an operating state in which the opening of the throttle valve 12 is large), the inside of the intake pipe 9 downstream of the throttle valve 12 becomes substantially atmospheric pressure, but the combustion chamber Since the amount of blow-by gas blown from 5 to the first space portion 50 increases, the amount of blow-by gas guided from the first air space 50 to the second space portion 51 increases accordingly, so that the second space portion increases. The pressure in 51 becomes higher than the pressure in the intake pipe 9 downstream of the throttle valve 12.

In this case, the PCV valve 63 is opened to connect the intake pipe 9 downstream of the throttle valve 12 and the second space 51. Then, the blow-by gas in the second space 51 flows into the intake pipe 9 downstream of the throttle valve 12. The blow-by gas that has flowed into the intake pipe 9 downstream of the throttle valve 12 from the second space 51 is sucked into the internal combustion engine 1 with the fresh air flowing from the upstream of the throttle valve 12 and re-combusted.

Further, since the pressure in the intake pipe 9 upstream of the throttle valve 12 is also substantially atmospheric pressure, the pressure in the second space 51 becomes higher than the pressure in the intake pipe 9 upstream of the throttle valve 12. In this case, the blow-by gas in the second space 51 flows into the intake pipe 9 upstream of the throttle valve 12 via the first recirculation passage 61. Second space portion 51
The blow-by gas that has flowed into the intake pipe 9 via the first recirculation passage 61 is sucked into the internal combustion engine 1 along with the fresh air flowing from the upstream side of the intake pipe 9 and re-combusted.

As a result, when the amount of blow-by gas generated is large as in the case where the internal combustion engine 1 is in a high-load operating state, the blow-by gas in the first space 50 and the second space 51 is In addition to the second recirculation passage 62, it is recirculated to the intake pipe 9 via the first recirculation passage 61.
It is possible to reliably scavenge a large amount of blow-by gas in the space 50 and the second space 51.

Next, the internal combustion engine 1 is provided with a combustion heater 13 for burning the fuel independently of the internal combustion engine 1. As shown in FIG. 2, the combustion heater 13 includes an outer cylinder 130, an intermediate cylinder 131 installed in the outer cylinder 130, and a combustion cylinder 132 installed in the intermediate cylinder 131.

Between the outer cylinder 130 and the intermediate cylinder 131, an in-heater cooling water passage 200 for flowing cooling water for the internal combustion engine 1 is formed. In the outer cylinder 130, a cooling water introduction port 133 for taking cooling water into the heater cooling water passage 200, and the heater cooling water passage 20.
Cooling water discharge port 134 for discharging the cooling water in 0
And are formed.

A cooling water introducing pipe 14 is connected to the cooling water introducing port 133, and a cooling water discharging pipe 15 is connected to the cooling water discharging port 134. Cooling water introduction pipe 14
As shown in FIG. 1, the cooling water discharge pipe 15 and the cooling water discharge pipe 15 are
It is connected to a water jacket (not shown).

A fuel evaporation section (wick) 140 is provided at the base end of the above-mentioned combustion cylinder 132. The wick 140 has a fuel introduction pipe 1 for guiding a part of the fuel discharged from the fuel pump for the internal combustion engine 1 to the wick 140.
41 is connected. In the vicinity of the wick 140 in the combustion cylinder 132, a fuel vaporization glow plug 142 for vaporizing the fuel supplied from the fuel introduction pipe 141 to the wick 140, and the vaporization by the fuel vaporization glow plug 142. And a glow plug 143 for igniting fuel for igniting the fuel.
The fuel vaporization glow plug 142 and the fuel ignition glow plug 143 may be combined into a single glow plug.

A blower fan 150 for sending combustion air to the combustion cylinder 132, and a fan motor 151 for rotationally driving the blower fan 150 are provided in the outer cylinder 130.
A housing 152, in which is installed, is attached.

The housing 152 has an intake port 15 for taking in combustion air into the housing 152.
3 is formed. The intake port 153 is connected to the intake introduction passage 16. This intake introduction passage 16
Is connected to the intake pipe 9 upstream of the throttle valve 12 or to the atmosphere open end.

Through holes 132a are provided at a plurality of locations on the peripheral wall of the combustion cylinder 132 so that the combustion cylinder 132 and the housing 152 communicate with each other, and the air blown out by the blower fan 150 inside the housing 152 is provided. Through the through hole 132a
It is possible to flow in.

A combustion gas passage 201 for flowing the combustion gas generated in the combustion cylinder 132 is formed between the intermediate cylinder 131 and the combustion cylinder 132. The intermediate cylinder 13
1, a combustion gas discharge port 154 for communicating the combustion gas passage 201 with the outside of the outer cylinder 130.
Are formed.

A combustion gas discharge passage 17 is connected to the combustion gas discharge port 154. The combustion gas discharge passage 17 is connected to a three-way switching valve 170, as shown in FIG.

In addition to the combustion gas discharge passage 17 described above, the three-way switching valve 170 includes a first discharge passage 171 and a second discharge passage 171.
Of the three-way switching valve 17
0 interrupts either the first discharge passage 171 or the second discharge passage 171, so that the first discharge passage 17
Either the first exhaust passage 172 or the second exhaust passage 172 can be electrically connected to the combustion gas exhaust passage 170.

The first exhaust passage 171 has the internal combustion engine 1
Of the first space 50. The second exhaust passage 172 is connected to a portion of the exhaust pipe 10 upstream of an exhaust purification catalyst (not shown). The second discharge passage 172 may be connected to the intake pipe 9.

In the combustion heater 13 having the above-mentioned structure, when the fuel vaporization glow plug 142, the fuel ignition glow plug 143, the fan motor 151, the electric water pump 18, and the fuel pump (not shown) are activated, the fuel pump operates. The fuel in a fuel tank (not shown) is sucked up and supplied to the wick 140 of the combustion cylinder 132, and the fan motor 151 operates the blower fan 150 to take in a part of the air flowing in the intake pipe 3 into the housing 152. It is sent toward the inside of the combustion cylinder 132. The air sent by the blower fan 150 flows into the combustion cylinder 132 through the through hole 132a.

The fuel supplied to the wick 140 is
It is heated and vaporized by the fuel vaporization glow plug 142, and is mixed with the air supplied by the blower fan 150 to form a mixture. The mixture is further heated by the glow plug 143 for igniting the fuel, and ignites and burns.

The air-fuel mixture (combustion gas) burned in the combustion cylinder 132 is discharged from the combustion cylinder 132 into the combustion gas passage 20 by the pressure of the air sent by the blower fan 150.
1, and then discharged from the combustion gas passage 201 to the combustion gas discharge port 154.

The combustion gas discharged to the combustion gas discharge port 154 reaches the three-way switching valve 170 via the combustion gas discharge passage 15. At that time, the three-way switching valve 170 is the first
If the second exhaust passage 172 and the combustion gas exhaust passage 170 are connected to each other by shutting off the exhaust passage 171 of the above, the combustion gas exhausted from the combustion heater 13 passes through the second exhaust passage 172. It is guided to the exhaust pipe 10 of the internal combustion engine 1. On the other hand, if the three-way switching valve 170 blocks the second exhaust passage 172 and connects the first exhaust passage 171 and the combustion gas exhaust passage 170, the combustion heater 1
The combustion gas discharged from No. 3 is guided to the first space 50 of the internal combustion engine 1 via the first discharge passage 171.

In the combustion heater 13, the heat of the combustion gas flowing in the combustion gas passage 201 is transferred to the cooling water flowing in the heater cooling water passage 200 via the wall surface of the intermediate cylinder 131, so that the heater internal cooling is performed. The temperature of the cooling water flowing through the water channel 200 will rise.

The cooling water whose temperature has risen in the heater cooling water passage 200 is discharged from the heater cooling water passage 200 to the cooling water discharge pipe 15 through the cooling water discharge port 134. The cooling water discharged to the cooling water discharge pipe 15 is
It is returned to the water jacket of the internal combustion engine 1 and circulates in the water jacket. At that time, the heat of the cooling water is transferred to the internal combustion engine 1 through the wall surface of the water jacket, and the warm-up of the internal combustion engine 1 is promoted.

If a heater core for heating the room is provided in the middle of the cooling water discharge pipe 15, the heat of the cooling water discharged from the combustion heater 13 flows through the heater core. Is transmitted to the heating air, and the heating air is warmed. As a result, it becomes possible to improve the indoor heating performance even in a situation where the temperature of the cooling water circulating in the water jacket of the internal combustion engine 1 is low.

The above-mentioned internal combustion engine 1 and combustion heater 13
Includes an electronic control unit ECU (Electronic Control Unit) for controlling the operating states of the internal combustion engine 1 and the combustion heater 13.
Control Unit) 300 is installed side by side.

The ECU 300 includes a CPU, ROM, RA
It is a logical operation circuit composed of M, a backup RAM, and the like. The ECU 300 includes a water temperature sensor 110 which is attached to the internal combustion engine 1 and outputs an electric signal corresponding to the temperature of the cooling water flowing in the water jacket, a starter switch 310 provided inside the vehicle, and a water temperature sensor inside the vehicle. The ignition switch 320 provided is connected and the output signals thereof are input to the ECU 320.

Further, the above-mentioned combustion heater 13 and the three-way switching valve 170 are electrically connected to the ECU 300,
The ECU 300 uses the combustion heater 13 and the three-way switching valve 170.
It is possible to control.

Hereinafter, the combustion heater 1 by the ECU 300 will be described.
The control method of the three-way switching valve 170 will be described.

The ECU 300 executes a start-time heater control routine as shown in FIG. 3 triggered by the ignition switch 320 being switched from OFF to ON. The above-described heater control routine at startup is executed by the ECU 3
00 is a routine stored in advance in the ROM.

In the start-up heater control routine, the EC
The U300 first determines in S301 whether or not the ignition switch 320 has been switched from off to on.

If it is determined in S301 that the ignition switch 320 has not been switched from off to on, the ECU 300 ends the execution of this routine.

On the other hand, if it is determined in S301 that the ignition switch 320 has been switched from OFF to ON, the ECU 300 proceeds to S302.

In S302, the ECU 300 reads the output signal value (cooling water temperature): THW of the water temperature sensor 110.

In S303, the ECU 300 determines that the above S3.
It is determined whether the cooling water temperature: THW read in 02 is lower than a predetermined temperature. Here, the above-mentioned predetermined temperature is, for example, a temperature corresponding to the temperature of the cooling water after completion of warming up of the internal combustion engine 1.

In S303, the cooling water temperature: TH
If it is determined that W is lower than the predetermined temperature, the ECU
Since the temperature of the internal combustion engine 1 is low in 300, it is considered that the internal combustion engine 1 needs to be warmed in advance before starting.
In 309, the residual heat treatment of the internal combustion engine 1 is executed.

Specifically, the ECU 300 firstly executes S30.
In 4, the operation of a starter motor (not shown) is prohibited.

In S305, the ECU 300 controls the three-way switching valve 170 to shut off the second discharge passage 172. In this case, the three-way switching valve 172 is connected to the first discharge passage 1
71 and the combustion gas discharge passage 17 are electrically connected.

In step S306, the ECU 300 operates the combustion heater 13 to activate the fuel vaporization glow plug 1.
42, glow plug 143 for fuel ignition, blower fan 15
0, and the fuel pump is activated.

In this case, the high-temperature combustion gas discharged from the combustion type heater 13 passes through the combustion gas discharge passage 17 → three-way switching valve 170 → the first discharge passage 171 in the first space of the internal combustion engine 1. Introduced into part 50. First space 50
The combustion gas introduced into the intake pipe 9 flows into the second space 51 through the blow-by gas passage 60, and then flows from the second space 51 through the first recirculation passage 61 into the intake pipe 9 upstream of the throttle valve 12. Flows into the site. The combustion gas flowing into the intake pipe 9 is released from the intake pipe 9 into the atmosphere via the air cleaner box 11.

At this time, the heat of the combustion gas is generated by the oil pan 1d.
Engine oil stored therein, cylinder block 1a, crankshaft 3, connecting rod 4,
It is transmitted to the piston 2, the cylinder head 1b, the intake camshaft 70, the exhaust camshaft 80, and the like.

Therefore, it is possible to reduce the viscosity of the engine oil and increase the ambient temperature in the combustion chamber 5 and the intake port 6, and at the same time, increase the crankshaft 3, intake camshaft 70, exhaust camshaft. It is possible to appropriately increase the oil clearance of the journal portion such as 80.

Returning to FIG. 3, when the ECU 300 finishes executing the above-described processing of S306, the ECU 300 activates the counter C in S307. This counter: C is a counter that measures the elapsed time from the operation start timing of the combustion heater 13.

In S308, the ECU 300 determines whether or not the measurement time of the counter C is a predetermined time or longer. Here, the above-mentioned predetermined time is the combustion type heater 13
Is the time required to raise the temperature of the internal combustion engine 1 to a desired temperature range by the combustion gas, and may be a fixed value that is experimentally obtained in advance. Cooling water temperature at the start of execution of preheat treatment: THW Or may be a variable value determined according to the outside air temperature or the like.

If it is determined in S308 that the measurement time of the counter C is less than the predetermined time, E
The CU 300 repeatedly executes the processing of S308 until the measurement time of the counter C is equal to or longer than the predetermined time.

In this case, the high temperature combustion gas discharged from the combustion type heater 13 is kept in the internal combustion engine 1 within the predetermined time.
Inside (first space 50, blow-by gas passage 60,
Since the second space 51) continues to flow, the internal combustion engine 1 quickly rises to a desired temperature range.

When it is determined in S308 that the measurement time of the counter C is equal to or longer than the predetermined time, E
The CU 300 proceeds to S 309 and proceeds to the first discharge passage 171.
And the second exhaust passage and the combustion gas exhaust passage 1
The three-way switching valve 170 is controlled so as to establish electrical connection with the switch 7.

In this case, the combustion gas discharged from the combustion heater 300 is the combustion gas discharge passage 17, the three-way switching valve 1
70 and the second combustion gas passage 172 to flow into a portion of the exhaust pipe 10 upstream of the exhaust purification catalyst. Since the high temperature combustion gas flowing into the exhaust pipe 10 is released into the atmosphere via the exhaust purification catalyst, the heat of the combustion gas is transferred to the exhaust purification catalyst, and the exhaust purification catalyst is activated quickly. .

Returning to FIG. 3, when the ECU 300 finishes executing the above-described processing of S308, the ECU 300 permits the operation of the starter motor and starts the internal combustion engine 1 in S310.

When it is determined in S303 that the cooling water temperature: THW is equal to or higher than the predetermined temperature, the ECU 300 uses the combustion heater 13 because the internal combustion engine 1 is sufficiently warmed. Considering that it is not necessary to preheat the internal combustion engine 1, the processes of S304 to S309 are skipped and the process proceeds to S310. Then, the ECU executes S31
At 0, the operation of the starter motor is permitted and the execution of this routine ends.

As described above, the ECU 300 executes the above-described start-up heater control routine to reduce the viscosity of the engine oil before starting the internal combustion engine 1 and reduce the ambient temperature in the combustion chamber 5 and the intake port 6. Since the rise and the appropriate increase of the oil clearance are achieved, the friction at the time of starting the internal combustion engine 1 and immediately after the starting is reduced, and as a result, the startability is improved and the fuel consumption rate after the start is improved. become.

Further, in the start-up heater control according to the present embodiment, the combustion gas of the combustion heater 13 is supplied to the exhaust purification catalyst after the internal combustion engine 1 is started, so that the exhaust purification catalyst is activated early. It is also possible to improve the exhaust emission.

[0082]

The internal combustion engine having the combustion heater according to the present invention utilizes the combustion gas of the combustion heater to directly heat the internal combustion engine body before starting the internal combustion engine, so that the crank journal and the camshaft are Since the oil clearance of the journal etc. can be made an appropriate clearance, it is possible to reduce the friction of the internal combustion engine at the time of starting and immediately after the starting, thereby improving the startability of the internal combustion engine and the fuel consumption rate after starting. It becomes possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine to which the present invention is applied.

FIG. 2 is a diagram showing an internal configuration of a combustion heater.

FIG. 3 is a flowchart showing a heater control routine at startup.

[Explanation of symbols]

1 ... Internal combustion engine 1a: Cylinder block 1b ... Cylinder head 1c ... crank case 1d ... oil pan 2 ... Piston 3 ... Crank shaft 4 ... Connecting rod 9 ... Intake pipe 10 ... Exhaust pipe 13 ... Combustion heater 17 ... Combustion gas discharge passage 50: first space 51 ... Second space portion 60 ... Blow-by gas passage 61 ... First return passage 62 ... Second return passage 63 ... PCV valve 70 ... Intake camshaft 80 ... Exhaust camshaft 170 ··· Three-way switching valve 171 ... First discharge passage 172 ... Second discharge passage

Claims (2)

[Claims] 1. A blow-by gas recirculation passage formed in an internal combustion engine, a combustion type heater that burns fuel independently of the internal combustion engine, and a combustion gas discharged from the combustion type heater before starting the internal combustion engine. An internal combustion engine having a combustion heater, comprising: a supply unit that supplies the blow-by gas passage. 2. The blow-by gas passage is a passage extending from a crankcase of the internal combustion engine to an intake passage of the internal combustion engine through a cylinder block and a cylinder head in sequence, and the supply means starts the internal combustion engine. An internal combustion engine having a combustion heater according to claim 1, wherein combustion gas discharged from the combustion heater is supplied to the crankcase before.