JP3528593B2 - Internal combustion engine having a combustion heater - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine 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 accelerate warming of the internal combustion engine. .

[0002]

2. Description of the Related Art A technique for heating engine cooling water of an internal combustion engine with a combustion heater is well known, and is disclosed in, for example, Japanese Patent Laid-Open No. 62-75.
No. 069 publication. In this publication, a combustion heater is arranged inside the intake pipe, and one end of a heating pipe penetrating a cooling water chamber of an engine is connected to a portion of the intake pipe downstream of the combustor and the other end thereof is connected to an exhaust pipe. However, an on-off valve is provided in the middle of the heating pipe, and an electric fan is provided in the intake pipe upstream of the combustion heater to suck the combustion air by the electric fan.

[0003]

In such a device, the combustion heater is separate from the internal combustion engine,
For this reason, the device tends to be large-sized, and problems such as difficulty in mounting and placement on a vehicle are likely to occur.

Therefore, it is desired that the combustion type heater is integrated with the cylinder block of the internal combustion engine so as to be integrated with the engine body as much as possible.

However, the greater the degree of integration with the internal combustion engine, the greater the influence of heat and vibration generated from the internal combustion engine. For example, an electric fan is provided to introduce combustion air into the combustion heater, but when vibration is applied to the electric fan, the durability of the electric fan deteriorates.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to avoid the adverse effects of vibration and heat transfer that occur when a combustion heater is integrated with an internal combustion engine.

[0007]

In order to solve the above problems, an internal combustion engine having a combustion heater according to the present invention has the following constitution.

That is, the present invention relates to an internal combustion engine having a combustion heater which is provided to heat an engine-related element and is configured to suck combustion air by an electric fan, and an integral structure with a cylinder block of the internal combustion engine. Was done
Or before placed in direct contact with the cylinder block
Air is supplied to the main body of the combustion heater and the combustion heater.
The air pipe to be supplied and the combustion type by means of the air pipe.
An electric fan that separates from the heater and sends air to the air pipe.
And a vibration absorbing portion provided on the air tube.

Here, it is preferable that the vibration absorbing portion is composed of an elastic tube which also serves as an air tube. The elastic tube is preferably an elastic tube having vibration resistance and heat resistance as well as a bellows-like elastic tube.

Further, it is preferable that the internal combustion engine has an intake pipe for introducing air into the engine, and the electric fan is connected to the intake pipe in order to introduce air from an engine intake system. Furthermore, the vibration absorber also serves as an air tube.
It is preferable that the elastic fan is formed of a bending elastic tube, and the electric fan is connected to the elastic tube portion.

Examples of the vibration absorbing portion include a vibration resistant and heat resistant damper that suppresses vibration around the air tube, such as heat resistant rubber and elastomer. It is also possible to construct the intake pipe by a vibration-absorbing laminated structure in which metal, rubber, and other vibration-proof materials are laminated.

As a result of the above, the electric fan is physically and thermally separated from the combustion type heater integrated with the internal combustion engine through the air pipe. In addition, similarly, a control computer for driving the electric fan,
When separated from the combustion heater and integrated with, for example, a computer for controlling the engine, the computer can be protected from vibration and heat.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. <Overall Description of Device> An engine 1 as an internal combustion engine is a water-cooled type, and includes an engine body 3, an intake device 5 for sending air required for combustion into a plurality of cylinders (not shown) of the engine body 3, and the inside of the cylinder. The exhaust device 7 emits exhaust gas into the atmosphere after combustion of the air-fuel mixture, and the vehicle interior heater 9 that warms the interior of the vehicle in which the engine 1 is mounted. Further, the engine 1 is provided with a cooling water pump 11 which causes the engine cooling water to flow through a cooling water circulation passage 10 which will be described below, by using the rotational force of a crankshaft (not shown) as a drive source. <Description of Device Components> (Engine Main Body) The engine main body 3 has a water jacket, which is a cooling water passage (not shown) in which cooling water circulates. Then, starting from the water jacket, the combustion heater 17 and the engine body 3 which belong to the intake device 5 and are directly attached to the engine body 3 through the water pipes W1 (see FIG. 2), W2 and W3 (see FIG. 1). Cooling water circulation passage 10 that circulates between external vehicle interior heaters 9
To form. The water conduit W1 connects the combustion heater 17 and the water jacket, and the other water conduit W1.
2, very short compared to W3. This is a combustion heater 17
Is directly attached to the engine body 3 and is embedded in the water jacket, or even if it goes out of the water jacket, the length is extremely short. Therefore, W1 is not shown in FIG. 1, which schematically shows the entire configuration of the apparatus, and is schematically shown in FIG. 2, which is an enlarged view of the combustion heater 17. (Intake Device) The intake device 5 uses an air cleaner 13 that takes in fresh air into the cylinder as a starting end of the intake device 5. Then, between the air cleaner 13 and an intake port (not shown) of the engine body 3 which is the end of the intake device 5,
A compressor 15a of a turbocharger 15, which is an intake system structure, a combustion heater 17, an intercooler 19, and an intake manifold 21 are provided.

These intake system structures belong to an intake pipe 23 having a plurality of connecting pipes. (Intake Pipe) The intake pipe 23 is located at the boundary of the compressor 15a.
The downstream side connecting pipe 2 in which the outside air entering the intake device 5 is forcibly pushed by the compressor 15a to be in a pressurized state
7 and the upstream side connecting pipe 25 which is not so. (Upstream Connection Pipe) The upstream connection pipe 25 is the air cleaner 1
3, a main flow pipe 29 formed of a bellows-like elastic pipe extending toward the compressor 15a, and a heater branch pipe 31 as a tributary pipe connected to the main flow pipe 29 in a bypass shape. An aeroflow meter AFM is provided in the middle of the passage extending from the main flow pipe 29 to the compressor 15a. (Heater Branch Pipe) The heater branch pipe 31 includes the combustion type heater 17 in the middle thereof, connects the upstream side portion of the combustion type heater 17 in the air flow direction to the main flow pipe 29, and burns from the main flow pipe 29. Air supply passage 33 for supplying fresh air, that is, air to the heater 17, the downstream side portion of the combustion heater 17 in the air flow direction, and the main pipe 29 (the intake pipe 2
3) and a combustion gas discharge passage 35 for discharging the combustion (exhaust gas) emitted from the combustion heater 17 to the main flow pipe 29.

An electric fan 45 is provided between the main flow pipe 29 and the air supply passage 33 to send fresh air in the main flow pipe 29 to the air supply passage 33. The air supply passage 33 and the combustion gas discharge passage 35 from the main flow pipe 29 are the "air pipe for introducing the air sucked by the electric fan into the internal combustion engine body" in the present invention.

Then, in both the air supply passage 33 and the combustion gas discharge passage 35, vibration absorbing portions 33a, 35 are provided in the middle thereof.
a is provided. The air supply passage 33 and the combustion gas discharge passage 35 are each made of a metal pipe, but the air pipe portion constituting each of the vibration absorbing portions 33a and 35a is made of a bellows-like elastic pipe to obtain vibration absorbing performance. It has a. The electric fan 45 is directly connected to the elastic tube forming the air supply passage 33. Further, since the main flow pipe 29 is also formed of an elastic pipe, the electric fan 45 is arranged in the middle of the elastic pipe path including the main flow pipe 29 and the air supply passage 33. The vibration absorbing parts 33a, 3
5a may be provided on the entire air supply passage 33 and the combustion gas discharge passage 35, or may be provided on a part thereof. Further, the vibration absorbing section is not limited to the bellows-like elastic tube, and may be formed by winding rubber or elastomer around the tube, or by forming a tube with a laminated plate of rubber or elastomer and a metal plate.

The air relating to the heater branch pipe 31 is
Not only the fresh air a1 entering the heater branch pipe 31 via the air cleaner 13, but also the combustion gas a2 emitted from the combustion heater 17. Bake type heater 17
The combustion gas is a smoke-free gas, in other words, a carbon-free gas. Therefore, it can be used as intake air for an internal combustion engine.

Of the connection points c1 and c2 of the air supply passage 33 and the combustion gas discharge passage 35 to the main flow pipe 29, the connection point c1 is located on the upstream side of the main flow pipe 29 with respect to the connection point c2. Therefore, the air a1 from the air cleaner 13 is first connected to the heater branch pipe 31 at the connection point c1.
The main flow pipe 29 is divided into the air a1 'that branches toward the connection point c2 and the air a1' that flows toward the connection point c2 without branching. Further, at the connection point c2, the air a2 that has branched at the connection point c1 and has been used for combustion by the combustion heater 17 and has become combustion gas merges with the fresh air a1 ′ that has not branched at c1 to mix combustion gas. Air a
It will be 3.

The air a1 branched at the connection point c1 passes through the electric fan 45, the air supply path 33, the combustion type heater 17 and the combustion gas discharge path 35 from the connection point c2 to the main flow pipe 29.
And return to the air a2. Air a returning to the main pipe 29
Reference numeral 2 is a combustion gas that has been heated by the combustion heater 17 and has heat. Therefore, this gas is returned to the main flow pipe 29 and merges with the unbranched air a1 ′ at the connection point c2 and burns. When the gas-containing air a3 is formed, as a result, the combustion gas-containing air a3 becomes high-temperature intake air that enters the engine body 3.

Further, in FIG. 1, the downstream side connecting pipe 27
Is the compressor 15a and the intake manifold 21.
It is a pipe that connects with and the one shown in FIG. 1 is L-shaped. Further, an intercooler 19 is arranged near the intake manifold 21. (Exhaust device 7) On the other hand, the exhaust device 7 has an exhaust port (not shown) of the engine body 3 as a start end of the exhaust device 7, and an exhaust manifold 37 and a turbocharger 15 between the exhaust port 7 and the muffler 41 at the end of the exhaust device 7. The turbine 15b and the exhaust catalyst 39 are provided on the exhaust pipe 42. Since these are well known and are not directly related to the present invention, description thereof will be omitted. The air flowing through the exhaust device 7 is indicated by the symbol a4 as the exhaust gas of the engine 1. (Combustion type heater) The structure of the firing type heater 17 is shown in FIG.

The combustion heater 17 is connected to the water jacket of the engine body 3 through a water pipe W1, and the combustion heater 17 has a cooling water passage 17a therein through which the cooling water from the water jacket passes. Have. As can be seen from FIG. 1, the combustion heater 17 is directly attached to the engine body 3. In this connection,
Although the water pipe W1 is not shown in FIG. 2, the water pipe W1 communicating with the water jacket is shown in FIG.

The cooling water (shown by a broken line arrow in the figure) flowing through the cooling water passage 17a passes around the combustion chamber 17d, which is a combustion portion formed inside the combustion heater 17, so as to pass between them. Then, it receives heat from the combustion chamber 17d and becomes warm. This will be described in detail in order.

The combustion chamber 17d is composed of a combustion cylinder 17b as a combustion source that emits a flame, and a cylindrical partition wall 17c that covers the combustion cylinder 17b to prevent the flame from leaking to the outside. By covering the combustion cylinder 17b with the partition wall 17c, the combustion chamber 1
7d is defined in the partition wall 17c. And this partition wall 17
c is also covered with the outer wall 43a of the combustion chamber main body 43 of the combustion heater 17, and there is a space between them. By providing this space, the cooling water passage 17a is formed between the inner surface of the outer wall 43a and the outer surface of the partition wall 17c.

Further, the combustion chamber 17d is provided with the air supply passage 3
3 has an air supply port 17d1 and an exhaust gas outlet 17d2 which are directly connected to the combustion gas exhaust passage 35.

Air a1 flowing from the air supply passage 33
When the air enters the combustion chamber 17d from the air supply port 17d1, it reaches the exhaust gas exhaust port 17d2 through the inside, and then flows through the combustion gas exhaust passage 35 to the main pipe 29 as the air a2 as described above. enter. Therefore, the combustion chamber 17d is in the form of an air passage through which the air a1 that changes due to combustion is passed to the air a2 in the combustion heater 17.

After the combustion heater 17 burns,
Air a returning to the main flow pipe 29 via the combustion gas discharge passage 35
2 is the exhaust gas emitted from the combustion type heater 17, and therefore has heat. Until the air a2 having this heat exits the combustion heater 17, the heat of the air a2 is transmitted to the cooling water flowing through the cooling water passage 17a through the partition wall 17c, and the cooling water is removed as described above. warm.
Therefore, the combustion chamber 17d is also a heat exchange passage.

The combustion cylinder 17b is provided with a fuel supply pipe 17e which is connected to the fuel pump P, and receives the pump pressure of the fuel pump P from the fuel supply pipe 17e to supply combustion fuel to the combustion cylinder 17b.
supply to b. The supplied combustion fuel is vaporized in the combustion heater 17 to become vaporized fuel, and the vaporized fuel is
It is ignited by an ignition source (not shown).

The air supply passage 33 and the combustion gas discharge passage 3
5 is used only for the combustion heater 17. Therefore, these belong to the combustion heater 17. The combustion chamber body 43 is configured integrally with the engine body. Here, the term "integrally" is not limited to the case where the combustion chamber body is completely integrated with the cylinder block, but when the combustion chamber body is placed in direct contact with the cylinder block, the combustion chamber body is The case where it is arranged in the vicinity of and is integrated as a whole is also included. (Cooling Water Circulation) Next, the circulation of cooling water will be described.

The cooling water passage 17a is connected to the water jacket of the engine body 3 and is provided with a cooling water inlet 17a1.
And a cooling water discharge port 17a2 connected to the vehicle interior heater 9.

The cooling water inlet 17a1 is used for the engine body 3
The water jacket W is connected to the water jacket W through the water conduit W1, and the cooling water discharge port 17a2 is connected to the vehicle interior heater 9 through the water conduit W2. These water lines W1
And W2, the combustion heater 17 is connected to the water jacket of the engine body 3 and the vehicle interior heater 9. In addition, the vehicle interior heater 9 and the engine body 3
Are also connected via a water conduit W3. In addition, water pipe W
1 water jacket connection point and water line W2
Water temperature sensors 40a and 40b are attached to the connecting points with the combustion heater 17. These water temperature sensors 40a and 40b are electrically connected to an engine electronic control unit (ECU) that controls the operation of the entire engine.

By connecting the engine main body 3, the combustion type heater 17, and the vehicle interior heater 9 using the water conduits W1, W2, and W3 in this way, the cooling water in the water jacket of the engine main body 3 is transferred to the water jacket. Starting from the above, the cooling water circulating passage 10 is formed by sequentially flowing from the next, returning to the water jacket again, and repeating this.

To describe the circulation of the cooling water in detail, the cooling water reaches the combustion type heater 17 from the cooling water introduction port 17a1 through the water pipe W1 from the water jacket.
It is heated there.

The cooling water warmed in (1) reaches the vehicle interior heater 9 from the cooling water discharge port 17a2 of the combustion type heater 17 through the water conduit W2.

After the cooling water is heat-exchanged by the heater 9 for the passenger compartment and the temperature of the cooling water is lowered, or when the operation of the heater 9 for the passenger compartment is stopped, the cooling water is passed through without being heat-exchanged. , Return to the water jacket via water conduit W3. (ECU 46 and related members electrically connected thereto) The ECU 46 includes various sensors (not shown) such as an outside air temperature sensor, a combustion gas temperature sensor, and a rotation speed sensor, the electric fan 45, the fuel pump P, and a central processing control. It is electrically connected via a device (CPU) 47. The CPU 47 drives and controls the electric fan 45 to exclusively control the operation of the combustion heater 17.
By being integrated with U, it is separated from the combustion heater 17 and is thermally and vibrationally shut off.

Then, the CPU 47 of the combustion type heater 17 operates according to each parameter of various sensors, thereby controlling the combustion state of the combustion type heater 17. In other words, the CPU 47 controls the momentum, size, temperature, etc. of the flame of the combustion heater 17, and the temperature of the exhaust gas (combustion gas) of the combustion heater 17 is controlled by this control.

The water pipe W1 is connected to the water jacket, that is, the temperature detected by a water temperature sensor 40a provided at the outlet of the water jacket, and the water pipe W2.
The temperature detected by the water temperature sensor 40b provided at the connection point with the combustion heater 17, that is, the outlet of the combustion heater,
These are referred to as the engine outlet water temperature and the combustion heater outlet water temperature, respectively, and are indicated by reference numerals T1 and T2, respectively. It can be said that these water temperatures T1 and T2 are the cooling water temperature before being heated by the combustion heater 17 and the cooling water temperature after being heated by the combustion heater 17, respectively.

Based on the temperatures T1 and T2 of the cooling water before heating by the combustion heater 17 and the cooling water after heating by the combustion heater 17, among the cooling water flowing through the cooling water circulation passage 10, What controls the output is the internal combustion engine having the combustion heater according to the embodiment of the invention.

Next, the operation control routine of the internal combustion engine having the combustion heater will be described with reference to the flowchart of FIG.

This routine is a part of a normal flow chart (not shown) for driving the engine 1, and comprises steps 101 to 108 described below. Also,
The operations in the following procedure are all performed by the ECU 46. Then, using the symbol S, for example, step 101
In that case, S101 is omitted.

After the engine 1 is started, when the process shifts to this routine, it is determined in S101 whether the engine outlet water temperature (temperature before heating by the combustion heater) T1 is equal to or lower than the complete warm-up completion temperature TT1. . As the temperature TT1 before completion of complete warming up, for example, 75 ° C.
Can be mentioned. The temperature at the time of completion of warm-up is, for example, 90 ° C.

A positive determination is made in S101, and the engine outlet water temperature T1 is the temperature before complete warm-up TT1 (75 in the above example).
(° C) or less, the process proceeds to the next S102 and a negative determination is made,
Engine outlet water temperature T1 is temperature TT1 before complete warm-up
When the temperature is higher than (75 ° C. in the above example), the process proceeds to S103.

In S102, the predetermined temperature TT required for controlling the output of the combustion heater 17 is set to TT2 + A, and in S103, the predetermined temperature TT is set to a fixed value TT2. Here, TT2 is 85 ° C. in the present embodiment. Also, A is a fixed value, and in this embodiment, it is 10 ° C.
Is. Therefore, since TT2 + A is an addition value of fixed values, this also becomes a fixed value, for example, 95 ° C. However, the value of A may be a variable value. S102 and S10
After setting the predetermined temperature TT in 3, the process proceeds to the next S104.

In S104, the combustion heater outlet water temperature T
It is determined whether 2 is equal to or higher than the predetermined temperature TT. S1
If the affirmative determination is made in 04, the processing proceeds to S105, and if the negative determination is made, the processing proceeds to S106. The predetermined temperature TT is S10.
Since it is compared with T2 at 4, the comparison temperature TT
Say.

In S105, the output value W of the combustion heater 17 is set to the low output value Lo or 0 (zero), and then the process proceeds to S108.

At S106, the combustion heater outlet water temperature T
2 is a temperature lower than the comparison temperature TT by B: TT-B as a reference, and it is determined whether the combustion heater outlet water temperature T2 is a value lower than that. Where B is a fixed value,
In this embodiment, the temperature is 20 ° C. If an affirmative decision is made in S106, the routine proceeds to the next S107, where the combustion heater 17
This time, the output value W of is set to Hi, and the process proceeds to S108. On the other hand, when a negative determination is made in S106, the process proceeds to S108 without passing through S107. Since the output value W of the combustion heater 17 is set to Hi, Lo, or 0 as a target, the output value W of the combustion heater 17 is hereinafter referred to as a “target output value W” unless otherwise specified.

At S108, the combustion heater 17 turns on S1.
The output of the combustion heater 17 is controlled so as to operate at the target output value W set in 05 or S107.
When the output value Lo set in S105 or 0 is set as the target output value W, the actual output of the combustion heater 17 becomes low (or stopped). Also, the target output value W
When the output value Hi set in S107 is set to
The actual output of the combustion heater 17 is high.

Next, based on FIG. 4, an output control state of the combustion type heater 17 when the flowchart of FIG. 3 is executed will be shown.

The vertical axis of FIG. 4 shows the degree of output of the combustion heater 17, and the horizontal axis shows the outlet water temperature T2 of the combustion heater. The broken line in FIG. 4 indicates the engine outlet temperature T
1 is the temperature before complete warm-up completion TT1 (75 ° C. in the above example) or less (when shifting from S101 to S102) shows the output control state of the combustion heater 17, and the solid line indicates that the engine outlet temperature T1 is completely warm. The output control state of the combustion heater 17 when the temperature is higher than the pre-completion temperature TT1 (75 ° C. in the above example) (when shifting from S101 to S103) is shown.

What the broken line means is that when the engine outlet temperature T1 is higher than the pre-complete warm-up completion temperature TT1 (75 ° C. in the above example), the combustion heater outlet water temperature T2 is TT2 + A (eg 95 ° C.). ), The combustion heater 17 indicates that its output switches from the high output to the low output. Then, when the combustion heater 17 has a low output, the combustion heater outlet water temperature T2 becomes TT2 + A−B (for example, 75 ° C.), the combustion heater 17 changes from a low output to a high output. Means to switch. Here, a hysteresis of B (for example, 20 ° C.) is provided between the time of switching from low output to high output and the time of switching from high output to low output, which may occur during output switching. Prevents hunting.

The solid line means that when the engine outlet temperature T1 is equal to or lower than the temperature TT1 before complete warm-up (75 ° C. in the above example), the combustion heater outlet water temperature T2 is TT2 (for example, 85 ° C.). (° C), the combustion heater 17 indicates that its output is switched from high output (the position of Hi on the vertical axis) to low output (the position of Lo or 0 on the vertical axis). When the output of the combustion heater 17 becomes low in this way and the combustion heater outlet water temperature T2 becomes TT2-B (for example, 65 ° C.), the combustion heater 17 will change from the low output to the above It means switching to high output. Here, between the time of switching from low output to high output and the time of switching from high output to low output, hysteresis is provided by B (for example, 20 ° C.) as in the case of the broken line. This prevents hunting that may occur during output switching.

As described above, when the combustion heater outlet water temperature T2 rises, the combustion heater 17 switches its output from high output to low output regardless of whether it is a solid line or a broken line. To prevent deterioration of durability.

On the other hand, the engine outlet water temperature T1 shown by the solid line
Is higher than the temperature TT1 before complete warming up, the temperature TT2 at which the combustion heater 17 switches from high output to low output
Compared with, the switching temperature TT2 + A of the combustion type heater 17 from the high output to the low output when the engine outlet water temperature T1 shown by the broken line is equal to or lower than the temperature TT1 before complete warm-up is high. Therefore, when the engine 1 is not warmed up sufficiently and the engine outlet water temperature T1 is low, the decrease in the output of the combustion heater 17 is suppressed, and the decrease in the warm-up property of the engine 1 can be prevented. <Operation and Effect of Embodiment> Next, the operation and effect of the internal combustion engine having the combustion heater according to the embodiment will be described.

In the internal combustion engine having the combustion heater, the combustion heater 17 of the cooling water flowing through the cooling water circulation passage 10 is used.
The output of the combustion heater 17 is controlled based on the temperature of each of the cooling water before heating by and the cooling water after heating by the combustion heater 17. Therefore, the heating state of the cooling water by the combustion heater 17 can be grasped from the temperature of the cooling water after heating by the combustion heater 17, and the output control of the combustion heater 17 can be controlled from this heating state. At this time, if the circulation amount of the cooling water changes depending on the rotation speed of the engine 1, it is impossible to grasp the warm-up state of the engine 1 only by the temperature of the cooling water after heating. However, in the engine 1 according to this embodiment, the temperature before the cooling water is heated by the combustion heater 17 is also taken into consideration, and the output of the combustion heater 17 is controlled based on this temperature. Therefore, the combustion heater 17
It is possible to heat the cooling water just enough. Therefore, there is no possibility that the engine warm-up performance is deteriorated or the output of the combustion heater is increased more than necessary and the heat resistance of the combustion heater 17 is impaired.

In the engine 1, when the engine rotational speed is low, the rotational speed of the cooling water pump (not shown) is also low, so that the circulation amount of the cooling water flowing through the cooling water circulation passage 10 is small. However, compared with the circulating amount of cooling water, the combustion type heater 17
Is high, the temperature after the cooling water is heated by the combustion heater 17 is sufficiently high. However, even if the amount of cooling water is small, warming up of the engine 1 is not necessarily promoted. This is because a sufficient amount of cooling water and a sufficient amount of heat received by this cooling water are required to promote warm-up. However, in the engine 1, when the temperature of the cooling water before heating by the combustion heater 17 is in a low temperature state, the predetermined temperature related to the temperature of the cooling water after heating is increased, so Warm-up promotion is performed more effectively.

Further, since the temperature of the cooling water before being heated by the combustion heater 17 is measured at or near the outlet of the water jacket provided in the engine body 3, the temperature of the engine body 3, that is, the actual warm-up temperature is accurately measured. Can be measured.

Since the cooling water temperature after heating by the combustion heater 17 is measured at or near the outlet of the combustion heater 17, the actual temperature of the combustion heater 17 can be accurately measured.

Further, since the combustion chamber main body 43 is constructed integrally with the engine main body, it is extremely easy to mount the internal combustion engine on a vehicle and is easy to handle. Then, the electric fan 45 is connected from the combustion type heater 17 integrated with the internal combustion engine through the vibration absorbing portion, and is vibrationally and thermally cut off. The adverse effect of can be avoided and durability can be improved. This also applies to the CPU 47 that controls the electric fan 45.

Since it is not necessary to use an expensive material for the heat damage countermeasure of the electric fan of the combustion heater and the CPU, the cost can be further reduced.

Further, since electronic parts such as a motor of an electric fan, which is weak against vibration, can be mounted on the vehicle body or on a vibration absorbing member such as a rubber part of an intake system of an engine, compared with a case where an electric fan is provided in a combustion heater. And can be easily inspected.

When the engine is stopped, it is possible to control the fuel pump P and the blower fan of the combustion type heater to be stopped immediately, whereby the motor of the electric fan of the combustion type heater and the control unit ECU and the engine after the engine is stopped. The heat damage to the rubber parts of the intake system can be prevented at the same time.

[0061]

As described above, according to the present invention, the electric fan is vibrationally cut off from the combustion type heater integrated with the internal combustion engine by the vibration absorbing portion, thereby avoiding the adverse effect of vibration. The durability can be increased. Also,
By avoiding the problem of integrating the internal combustion engine body and the combustion heater, the internal combustion engine body and the combustion heater can be integrated, and the vehicle mountability and reliability can be improved. It is possible to achieve cost reduction due to the cost reduction.

[Brief description of drawings]

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

FIG. 2 is a schematic sectional view of a combustion heater.

FIG. 3 is a flowchart showing an operation control routine of an internal combustion engine having a combustion heater according to an embodiment of the present invention.

FIG. 4 is a diagram showing an output control state of the combustion heater 17 when the flowchart of FIG. 3 is executed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine (internal combustion engine) 3 ... Engine main body (internal combustion engine main body) 5 ... Intake device 7 ... Exhaust device 9 ... Cabin heater 10 ... Cooling water circulation passage 11 ... Cooling water pump 13 ... Air cleaner 15 ... Turbocharger 15a ... Compressor 15b ... Turbine 17 of turbocharger ... Combustion heater 17a ... Cooling water passage 17a1 of combustion heater ... Cooling water inlet 17a2 ... Cooling water outlet 17b ... Combustion cylinder 17c ... Cylindrical partition 17d ... Combustion chamber 17d1 ... Air supply port 17d2 ... Exhaust exhaust port 17e ... Fuel supply pipe 19 ... Intercooler 21 ... Intake manifold 23 ... Intake pipe 25 ... Upstream connecting pipe 27 ... Downstream connecting pipe 29 ... Main pipe of intake pipe 31 ... Branch pipe for heater (air pipe) ) 33 ... Air supply path (air tube) 33a ... Vibration absorption section 35 of air supply path (air tube) ... Combustion gas discharge path (air tube) 3 a ... Vibration absorbing portion 37 of combustion gas exhaust passage (air pipe) ... Exhaust manifold 39 ... Exhaust catalyst 40a ... Water temperature sensor 40b ... Water temperature sensor 41 ... Muffler 42 ... Exhaust pipe 43 ... Combustion chamber body 43a ... Outer wall 45 ... Electric fan 46 ... ECU 47 ... CPU c1 ... Connection point c2 between air supply path 33 and main flow tube 29 ... Connection point between combustion gas discharge path 35 and main flow tube 29 T: Engine outlet water temperature T1 ... Water temperature provided at outlet of water jacket Sensor 4
Temperature detected by 0a (temperature of cooling water before heating) T2 ... Temperature detected by water temperature sensor 40b provided at the outlet of the combustion heater (temperature of cooling water before heating) TT ... Comparative temperature (predetermined temperature) TT1 ... Pre-Warm-up Temperature (Set Temperature) TT2 ... Fixed value TT2 + A ... Fixed value A ... Fixed value B ... Hysteresis W ... Output value of combustion heater 17 W1 ... Water conduit W2 ... Water conduit W3 ... Water conduit a1 ... From air cleaner 13 Outside air (fresh air) entering the mainstream pipe 29 a1 '... Air that does not branch at the connection point c1 and heads to the connection point c2 at the mainstream pipe 29 a2 ... Air that has been burned by the combustion heater 17 to become combustion gas a3 ... Combustion gas mixed air a4 ... Exhaust gas P of engine 1 ... Fuel pump

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Claims (5)

(57) [Claims] Claim: What is claimed is: 1. An internal combustion engine having a combustion heater which is provided for heating an engine-related element and which is configured to suck combustion air by an electric fan, which is integrated with a cylinder block of the internal combustion engine.
Said combustion placed in direct contact with the cylinder block
Type heater, an air pipe for supplying air to the combustion type heater, and the combustion type heater separated by the air pipe.
An internal combustion engine having a combustion heater , comprising: an electric fan that feeds air into the air pipe, and a vibration absorber provided in the air pipe. 2. The internal combustion engine having a combustion heater according to claim 1, wherein the vibration absorber is made of an elastic tube that also serves as an air tube. 3. The internal combustion engine having a combustion heater according to claim 2, wherein the elastic tube is a bellows-like elastic tube. 4. The internal combustion engine has an intake pipe for introducing air into the engine, and the electric fan is connected to the intake pipe for introducing air from an engine intake system. An internal combustion engine having the combustion heater according to claim 1. 5. The vibration absorbing portion is an elastic tube that also serves as an air tube.
The internal combustion engine having the combustion heater according to claim 4 , wherein the electric fan is connected to the elastic tube portion.