JP3577952B2 - Internal combustion engine having a combustion heater - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an internal combustion engine having a combustion-type heater, and more particularly, to an internal combustion engine having a combustion-type heater that enhances the startability of the internal combustion engine in cold weather and promotes warm-up.
[0002]
[Prior art]
It is desired that the internal combustion engine be enhanced in startability and promote warm-up especially in cold weather. Therefore, for example, Japanese Patent Application Laid-Open No. 62-75069 discloses that engine cooling water is warmed by utilizing combustion heat generated by a vaporizing combustion heater attached to an intake passage of an internal combustion engine, thereby promoting warm-up and performance of a vehicle interior heater. This shows the technology for improvement. The vaporizing combustion heater vaporizes the liquefied fuel for combustion, ignites the vaporized fuel to create a fire, and grows the fire to generate a flame.
[0003]
As is well known, a general basic structure of an evaporative combustion heater includes a combustion chamber that generates a flame, a fuel supply unit that supplies liquefied fuel for combustion to the combustion chamber, and a liquefied fuel supplied by the fuel supply unit. A fuel vaporizing section to be vaporized; a glow plug as an ignition means for igniting the vaporized fuel vaporized by the fuel vaporizing section to generate a fire; and a blower fan for supplying air for growing the fire generated by the glow plug into a flame. A cooling water passage through which engine cooling water is passed to absorb the heat of combustion of the vaporizing combustion heater into the engine cooling water of the internal combustion engine to promote warm-up, and an air flow for supplying and discharging air to and from the combustion chamber. And at least a road. In addition, it is necessary to adjust the glow plug energizing time to make a fire, and to make the flame grow larger from the fire, it is necessary to make various adjustments such as the output of the blower fan, the air supply, and the fuel supply. There is. These adjustments are performed by a computer.
[0004]
[Problems to be solved by the invention]
By the way, even if the ignition, that is, the processing necessary for producing a fire type is performed, if a pressure difference occurs between the intake side and the exhaust side of the combustion type heater, the air flowing through the air flow passage of the combustion type heater due to the pressure difference The higher the speed, the harder it is for a lighter or match to ignite in a strong wind. Even if it can be done, it disappears immediately.
The present invention has been made in view of the above circumstances, and has as its technical object an internal combustion engine having a combustion-type heater that can reliably perform ignition.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, an internal combustion engine having a combustion heater according to the present invention employs the following means.
[0006]
(1) An internal combustion engine having a combustion-type heater according to the present invention is used as the combustion-type heater in an internal combustion engine having a combustion-type heater that operates when the internal combustion engine is in a predetermined operating state and raises the temperature of an engine-related element. Ignition means for igniting the fuel for combustion to produce a fire, a combustion chamber which is a room for growing the fire produced by the ignition means into a flame, an air supply path for supplying combustion air to the combustion chamber,While connected to the intake system of the internal combustion engine,A combustion gas discharge path for discharging combustion gas from the combustion chamber; and a pipe connecting the air supply path and the combustion gas discharge path.
[0007]
here,
{Circle around (1)} “When the internal combustion engine is in a predetermined operating state” means that the internal combustion engine is operating, or after the internal combustion engine is started, or when the internal combustion engine itself generates a small amount of heat during cold or extreme cold. For example, when the fuel consumption is small) and when the amount of heat received by the engine cooling water is small due to the small amount of heat generated by the internal combustion engine itself, or when the machine is warmed up immediately after starting at room temperature. The time when there is outside air in a temperature range of about 15 ° C. or so, and the extremely cold time is when there is outside air in a temperature range of about −10 ° C. or less.
[0008]
{Circle around (2)} “engine-related elements” refer to an engine cooling water body or an internal combustion engine body that introduces combustion gas of a combustion type heater into intake air.
[0009]
{Circle around (3)} As the “ignition means”, for example, a glow plug which generates heat when energized from a battery is preferable.
[0010]
{Circle around (4)} The "combustion chamber" has an air flow passage therein which is connected to the air supply passage and the combustion gas discharge passage.
[0011]
(5) "Tube" means a pipe through which air can flow between the air supply passage and the combustion gas discharge passage.
[0012]
{Circle around (6)} As the "combustion heater", a vaporization combustion heater is preferable. The combustion type heater has a combustion chamber connected to an intake pipe of the internal combustion engine via an air supply path or the atmosphere, and connected to an intake pipe of the internal combustion engine via a combustion gas discharge path. Therefore, the air enters the air supply path from the intake pipe or the atmosphere, and then, when this air enters the combustion chamber and is used for combustion, it eventually becomes combustion gas, returns to the intake pipe via the combustion gas discharge path, and thereafter, Is sent into the cylinder of the internal combustion engine main body, and then becomes combustion air for the internal combustion engine to be used again for combustion.
[0013]
It is necessary to adjust the time of energization (heating) of the glow plug in order to make a fire, and to make the fire grow from a fire to a flame, the output of the blower fan, the air supply, the fuel supply, etc. Needs to be adjusted. These adjustments are performed by a computer, that is, a central processing unit (CPU), which is a central part of an ECU (electronic control unit).Accordingly, an internal combustion engine having a combustion heater according to the present invention is a combustion engine having a combustion heater that operates when the internal combustion engine is in a predetermined operating state to increase the temperature of an engine-related element. An ignition means for igniting a fuel for use to produce a fire, a combustion chamber which is a room for growing the fire by the ignition means into a flame, an air supply path for supplying combustion air to the combustion chamber, and A combustion gas discharge path for discharging combustion gas from the chamber, a pipe connecting the air supply path and the combustion gas discharge path, and a blower fan provided upstream of a combustion chamber formed inside the combustion type heater. May be provided. Further, instead of a blower fan provided upstream of a combustion chamber formed inside the combustion type heater, a downstream side of a connection portion between the air supply path and the tube in the air flow direction of the air supply path. A ventilation fan provided on the side may be provided.
[0014]
The internal combustion engine having the combustion heater according to the present invention includes a pipe connecting the air supply path and the combustion gas discharge path, and the pipe is connected between the air supply path and the combustion gas discharge path as described above. Is to be distributed. Therefore, when the air flowing toward the combustion chamber through the air supply path reaches the pipe, the air branches there into the air flowing into the pipe and the air flowing toward the combustion chamber. Therefore, at least when the combustion type heater starts ignition, that is, in the case of the glow plug, when the glow plug generates heat by energization, the amount of air flowing through the pipe can be adjusted to reduce the amount of air flowing toward the combustion chamber. If the combustion type heater is sufficiently reduced or reduced to 0 (zero) to such an extent that it can be ignited, there is no fear that strong ventilation that cannot be ignited is generated in the air flow passage of the combustion chamber. Therefore, since strong wind does not occur in the air flow passage, the ignition of the combustion type heater can be reliably performed, that is, the fire type can be reliably ensured. Further, since ignition is reliable, not only generation of white smoke can be prevented, but also generation of unpleasant odor due to generation of unburned hydrocarbons can be prevented.
[0015]
(2) In the above item (1), it is preferable that the pipe is a communication passage that opens when the ignition unit starts ignition and communicates between the air supply passage and the combustion gas discharge passage. .
[0016]
In the internal combustion engine having the combustion type heater according to the present invention, the pipe is a communication path communicating between the air supply path and the combustion gas discharge path, and this communication path is used when ignition is started by ignition means. open. For this reason, even if the air flowing through the air flow passage of the combustion heater has a momentum, the air flows out to the combustion gas discharge passage through the communication passage. That is, the momentum diminishes. Therefore, if the opening amount of the communication passage is made sufficiently large, the amount of air flowing toward the combustion chamber can be sufficiently reduced or set to 0 (zero) to such an extent that ignition by the combustion type heater can be reliably performed. Therefore, there is no fear that strong ventilation that cannot ignite is generated in the combustion chamber. Since no strong wind is generated in the air flow passage of the combustion chamber, the ignition of the combustion heater can be reliably performed. In addition, since ignition is reliable, generation of unpleasant odor due to generation of white smoke and generation of unburned hydrocarbons can be prevented.
[0017]
(3) In (2), the communication path may be closed after the ignition by the ignition unit is completed.
[0018]
Here, “ignition completed” means that a fire is generated in the combustion chamber.
[0019]
In the internal combustion engine having the combustion heater according to the present invention, after the ignition is completed, that is, after the ignition type is secured, the communication passage is closed, so that the air that has flowed into the combustion gas discharge passage when the communication passage was open is removed from the combustion chamber. It will flow into. However, since the fire has already been made at this time, the fire can grow into a flame.
[0020]
(4) In the above (2) or (3), the communication path may include a communication path opening / closing unit.
[0021]
Here, the "communication passage opening / closing means" may be any means as long as it can control opening and closing of the communication passage, but at least air flowing through the communication passage when the combustion heater starts ignition by the ignition means. It is desired that the amount of air flowing through the air supply passage, the combustion chamber, and the combustion gas discharge passage located downstream of the communication passage can be greatly reduced or reduced to zero (0). The CPU also controls the communication passage opening / closing means.
[0022]
(5) An internal combustion engine having a combustion type heater according to the present invention is used as the combustion type heater in an internal combustion engine having a combustion type heater which operates when the internal combustion engine is in a predetermined operating state and raises the temperature of an engine-related element. An ignition means for igniting the fuel for combustion to produce a fire, a combustion chamber which is a room for growing the fire by the ignition means into a flame, and an air supply passage for supplying combustion air to the combustion chamber from the atmosphere. A combustion gas discharge path for discharging combustion gas from the combustion chamber;Along with being provided in the combustion gas discharge path, theMeans for reducing the amount of combustion gas flowing through the combustion gas discharge path when the ignition means starts ignition.
[0023]
Here, "when the internal combustion engine is in a predetermined operation state", "engine-related elements", "combustion heater", "ignition means" and "combustion chamber" are the same as those described in the above (1). Is the same.
[0024]
The "combustion gas amount reducing means" may be any means that can reduce the amount of combustion gas flowing through the combustion gas discharge path, but at least the combustion type heater is ignited by the ignition means. It is desired that the amount of the combustion gas flowing through the combustion gas discharge passage can be reduced to a large nose or set to 0 (zero) when starting the combustion. The combustion gas amount reducing means is controlled by the CPU, and by this control, the amount of combustion gas flowing through the combustion gas discharge path is adjusted.
[0025]
In the internal combustion engine having the combustion heater of the present invention,In addition to being provided in the combustion gas exhaust passage,A combustion gas amount reducing means for reducing the amount of combustion gas flowing through the combustion gas discharge path is provided, and the amount of combustion gas flowing through the combustion gas discharge path can be adjusted by the combustion gas amount reduction means.startIf the amount of the combustion gas flowing through the combustion gas discharge passage is sufficiently reduced or set to 0 (zero) by the above adjustment, the circulation in the air flow passage is suppressed, and the strong ventilation that cannot ignite is performed. Does not occur in the air flow passage. Therefore, since no strong wind is generated in the combustion gas discharge path, the ignition of the combustion heater can be reliably performed at once. Further, since ignition is reliable, not only generation of white smoke can be prevented, but also generation of unpleasant odor due to generation of unburned hydrocarbons can be prevented.
[0026]
(6) In the above item (5), it is preferable that the combustion gas amount reducing means is a valve device for narrowing the combustion gas discharge passage.
[0027]
The “valve device” refers to a device that includes a valve body that opens and closes the combustion gas discharge path, a drive unit that drives the valve body, and a CPU that controls the operation of the drive unit. The "drive unit" preferably includes an opening / closing mechanism that opens and closes the combustion gas discharge path by operating the valve body with an appropriate drive motor, that is, the opening degree of the throttle. When the flow rate of the combustion gas flowing through the combustion gas discharge path is reduced by closing the combustion gas discharge path by the valve element, the combustion gas discharge path is narrowed.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<First Embodiment>
(Engine 1)
The engine 1 as an internal combustion engine is a water-cooled type, and has an engine body 3 having a water jacket (not shown) through which cooling water, which is one of engine-related elements, circulates, and burns in a plurality of cylinders (not shown) of the engine body 3. And an exhaust gas after combusting a mixture of the air related to the intake device 5 and fuel injected by a fuel injection device (not shown) in the cylinder. The vehicle includes an exhaust device 7 and a vehicle interior heater 9 for warming the interior of a vehicle in which the engine 1 is mounted. The engine 1 is a diesel engine or a gasoline direct injection lean burn engine.
[0029]
(Suction device 5)
The intake device 5 has an air cleaner 13 that takes in fresh air into a cylinder as a start end of the intake device 5 and an intake port (not shown) of the engine body 3 as an end. In addition, a compressor 15a of the turbocharger 15, which is an intake system structure, a combustion heater 17 that burns under atmospheric pressure, an intercooler 19, and an intake manifold 21 are provided therebetween.
[0030]
These intake system structures belong to another intake system structure and belong to an intake pipe 23 as an intake passage having a plurality of pipes.
[0031]
(Intake pipe 23)
The intake pipe 23 is divided into a downstream connection pipe 27 that is in a pressurized state because the outside air entering the intake device 5 is forcibly pushed by the compressor 15a, and an upstream connection pipe 25 that is not so. Can be roughly classified.
[0032]
(Upstream connecting pipe 25)
In FIG. 1, one upstream connecting pipe 25 includes a rod-shaped main pipe 29 extending straight from the air cleaner 13 toward the compressor 15 a, and a heater branch pipe 31 serving as a branch pipe connected to the main pipe 29 in a bypass shape. Consists of
[0033]
(Outside air temperature sensor 32)
An outside air temperature sensor 32 is attached to a portion of the main pipe 29 near the downstream side of the air cleaner 13. The outside air A entering the main flow pipe 29 from the air cleaner 13 is fresh air for the engine 1 and the combustion type heater 17, and the temperature thereof is detected by an outside air temperature sensor 32.
[0034]
(Branch 31 for heater)
The heater branch pipe 31 has a substantially “U” -shaped overall shape, and includes the combustion heater 17 in an intermediate portion thereof. Further, as another component of the branch pipe 31 for the heater, an upstream portion of the combustion type heater 17 in the air flow direction is connected to the main flow pipe 29, and fresh air, that is, a combustion type air is supplied from the main flow pipe 29 to the combustion type heater 17. An air supply pipe 33 serving as an air supply path for supplying fresh air (air before combustion) a1 to be used for combustion of the heater 17, a downstream portion of the combustion type heater 17 in the air flow direction and the main pipe 29 are connected and burned. A combustion gas discharge pipe 35 is provided as a combustion gas discharge path for discharging combustion gas (post-combustion air) a2 from the type heater 17 to the main flow pipe 29. Therefore, the heater branch pipe 31 supplies and discharges air to the combustion heater 17 through the air supply pipe 33 and the combustion gas discharge pipe 35.
[0035]
(Connecting pipe 36)
Further, the branch pipe 31 for the heater is also provided with a connection pipe 36 as a pipe connecting the air supply pipe 33 and the combustion gas discharge pipe 35 near the main flow pipe 29. The connection pipe 36 is a pipe for flowing air between the air supply pipe 33 and the combustion gas discharge pipe 35. Further, a valve device 44 as a communication passage opening / closing means is installed in the center of the inside of the connection pipe 36.
[0036]
The air supply path 33 and the combustion gas introduction path 35 are used only for the combustion type heater 17, and the communication pipe 36 is connected to the air supply pipe 33, which is a pipe dedicated to the combustion type heater 17. These are members that belong to the combustion type heater 17 because they connect the combustion gas discharge pipes 35.
[0037]
(Valve device 44)
As shown in FIG. 4, the valve device 44 includes a valve body 44a functioning as a throttle valve, a drive motor 44b for opening and closing the valve body 44a, and an opening / closing mechanism installed between the drive motor 44b and the valve body 44a. The operation of the drive motor 44b is controlled by a computer, that is, a CPU (not shown) which is a central part of the ECU 46. Specifically, when the combustion type heater 17 starts ignition, the valve body 44a is opened, and when the ignition is completed, the valve body 44a is throttled, that is, closed. The communication passage 36 opens and closes in response to the movement of the valve body 44a, and the opening and closing causes the air to flow between the air supply pipe 33 and the combustion gas discharge pipe 35 or stops.
[0038]
Further, of the connection points c1 and c2 of the air supply pipe 33 and the combustion gas exhaust pipe 35 with the main pipe 29, the connection point c1 is located on the upstream side of the main pipe 29 from the connection point c2. Therefore, the outside air (fresh air) A from the air cleaner 13 is first divided into the air a1 that branches to the branch pipe 31 for the heater at the connection point c1 and the air a1 ′ that branches the main flow pipe 29 to the connection point c2 without branching. . The air a1 branched at the connection point c1 returns as air a2 from the connection point c2 to the main pipe 29 via the air supply pipe 33, the combustion heater 17 and the combustion gas discharge pipe 35. Further, the air a2 and the fresh air a1 'merge at the connection point c2, and become the combustion gas mixed air a3 which is the combustion air of the engine 1.
[0039]
In general, the combustion gas of the combustion type heater has almost no smoke in a normal combustion state, in other words, gas containing no carbon. The combustion type heater 17 according to this embodiment is also the same. Therefore, there is no problem even if the combustion gas a2 of the combustion heater 17 is used as intake air for the internal combustion engine.
(Downstream connecting pipe 27)
As shown in FIG. 1, the downstream connection pipe 27 is a pipe connecting the compressor 15a and the intake manifold 21, and has an L shape in this embodiment. In addition, an intercooler 19 is arranged in a portion of the downstream connection pipe 27 near the intake manifold 21.
[0040]
(Exhaust device 7)
On the other hand, the exhaust device 7 has an exhaust port (not shown) of the engine main body 3 as a start end of the exhaust device 7 and a muffler 41 which is an end of the exhaust device 7 between the exhaust port and an exhaust manifold 38 as an exhaust system structure. The turbine 15b of the charger 15 and the catalytic converter 39 are provided on an exhaust pipe 42, which is also an exhaust system structure. The air flowing through the exhaust device 7 is indicated by reference numeral a4 as the exhaust gas of the engine 1.
[0041]
(Combustion heater 17)
Next, the structure of the combustion type heater 17 is schematically shown in FIGS.
[0042]
The combustion type heater 17 controls the combustion state by the CPU.
[0043]
The combustion heater 17 is connected to the water jacket of the engine body 3, and the combustion heater 17 has an engine cooling water passage 17a through which engine cooling water flows from the water jacket. The engine cooling water flowing in the engine cooling water passage 17a (indicated by a broken arrow in FIG. 2) passes around a combustion chamber 17d formed inside the combustion type heater 17, and passes through the combustion chamber 17d. Warmed by the heat from
[0044]
(Combustion chamber 17d)
The combustion chamber 17d includes a combustion cylinder 17b as a combustion chamber for emitting a flame, and a cylindrical partition wall 17c that covers the combustion cylinder 17b to prevent the flame from leaking to the outside. The combustion chamber 17d is defined inside the partition 17c by covering the combustion cylinder 17b with the partition 17c. The partition wall 17c is also covered with the outer wall 43a of the combustion heater 17, with a space between them. By providing this interval, the engine cooling water passage 17a is formed between the inner surface of the outer wall 43a and the outer surface of the partition wall 17c.
[0045]
The combustion chamber 17d has an air supply port 17d1 and an exhaust discharge port 17d2 that are directly connected to the air supply pipe 33 and the combustion gas discharge pipe 35, respectively.
[0046]
Then, the air a1 that has entered the combustion chamber 17d from the air supply pipe 33 via the air supply port 17d1 reaches the exhaust outlet 17d2 via the combustion chamber 17d, and then from the combustion gas discharge pipe 35 as described above. As described above, the air flows into the main flow pipe 29 as air a2. Therefore, the combustion chamber 17d is in the form of a series of air flow passages for passing the air a1 that changes into the air a2 in the combustion type heater 17.
[0047]
After the combustion type heater 17 burns, the air a2 returning to the main pipe 29 via the combustion gas discharge pipe 35 has heat because it is the combustion gas discharged from the combustion type heater 17 as it were. Then, until the heated air a2 exits from the combustion heater 17 to the combustion gas discharge pipe 35, the heat of the air a2 is transmitted to the engine cooling water flowing through the engine cooling water passage 17a through the partition wall 17c, As described above, the engine cooling water is warmed, and the warmed engine cooling water is sent to the water jacket of the engine 1 to warm up the engine body 3.
[0048]
(Combustion cylinder 17b)
The combustion cylinder 17b has a fuel supply pipe 17e connected to a fuel pump (not shown), and receives the pump pressure of the fuel pump therefrom to supply combustion fuel to the combustion cylinder 17b. Therefore, the fuel pump and the fuel supply pipe 17e can be said to be fuel supply means. The fuel supply amount by the operation of the fuel pump is temporarily stored in a RAM (random access memory) of the ECU 46 for controlling the combustion state of the combustion heater 17 as an integrated value of the fuel supply amount from the start of the fuel pump operation. And call it to the CPU which is the central part of the ECU 46 as needed.
[0049]
(Liquefied fuel 18)
The supplied combustion fuel is a liquefied fuel 18, which is turned into a vaporized fuel 18 ′ through a fuel vaporization unit 17 f shown in FIG. 3. The vaporized fuel 18 ′ generates heat by energization from a battery (not shown), which is ignition means. The glow plug 17g ignites. When the glow plug 17g generates heat, the actual elapsed time Tm1 from the start of energization is counted by the timer Tim (see FIG. 1), and the value is also temporarily stored in the RAM. Then, it is called by the CPU as needed.
(Ion sensor 17h and fuel heating evaporation plate 17i)
In FIG. 3, reference numerals 17h and 17i denote an ion sensor as an ignition sensor and a fuel-heating evaporating plate, respectively. The vaporized fuel 18 'is ignited in the vicinity of the fuel heating and evaporating plate 17i, and a fire type F' serving as a source of the flame F is formed. What blows the fire type F 'into a flame is the blower fan 45.
[0050]
(Blower fan 45) The blower fan 45 is provided in the combustion chamber 17d in the form of an air flow passage.UpstreamLocated in. The output of the blower fan 45 is adjusted by controlling the operation of the CPU of the ECU 46. This output adjustment changes the amount of air flowing through the combustion chamber 17d. Therefore, the amount of air flowing through the combustion chamber 17d can be controlled by adjusting the output of the blower fan 45.
[0051]
(ROM of ECU 46)
The ROM (Read Only Memory; read only memory) of the ECU 46 stores a predetermined time T1 which is a reference time for executing the operation control of the fuel pump and is a comparison time with the elapsed time Tm1 from the start of energization of the glow plug 17g. Is remembered.
[0052]
(Circulation of engine cooling water)
Next, the circulation of the engine cooling water to the engine cooling water passage 17a will be described with reference to FIGS.
[0053]
(Engine cooling water passage 17a)
The engine cooling water passage 17a has a cooling water inlet 17a1 connected to the water jacket of the engine body 3, and an engine cooling water outlet 17a2 connected to the vehicle interior heater 9.
[0054]
(Water pipelines W1 to W3)
The engine coolant inlet 17a1 and the engine body 3 are connected via a water pipe W1, and the engine coolant outlet 17a2 and the vehicle interior heater 9 are connected via a water pipe W2. It is.
[0055]
The combustion heater 17 is connected to the water jacket of the engine body 3 and the vehicle heater 9 via the water pipes W1 and W2. Further, the vehicle interior heater 9 and the engine body 3 are also connected via a water pipe W3.
[0056]
Therefore, the engine cooling water in the water jacket of the engine body 3 flows from the engine cooling water inlet 17a1 to the combustion heater 17 via the water pipe W1 in the order of the flow, and is heated there. {Circle around (2)} The warmed engine coolant flows from the engine coolant outlet 17a2 of the combustion heater 17 to the vehicle heater 9 via the water pipe W2. {Circle around (3)} After the engine cooling water undergoes heat exchange by the vehicle interior heater 9 and its temperature drops, it returns to the water jacket via the water pipe W3. A water temperature sensor 47 for detecting the temperature of the engine cooling water is attached to the water jacket.
[0057]
As described above, the engine cooling water circulates between the engine main body 3, the combustion type heater 17, and the vehicle interior heater 9 via the water pipe W1, the water pipe W2, and the water pipe W3.
[0058]
(Electrical connection of sensors, etc. to ECU 46)
The ECU 46 is electrically connected to the ion sensor 17h, the outside air temperature sensor 32, and the water temperature sensor 47, the timer Tim, the blower fan 45, and the fuel pump. The CPU appropriately controls the combustion state of the combustion heater 17 in accordance with the parameters of the sensors 17h, 32 and 47, the timer Tim, the output value of the blower fan 45, and the fuel pump. The momentum, size, temperature, etc. of the 17 flames are maintained in an optimum state. Further, by controlling the combustion state of the combustion type heater 17 by the CPU, the temperature of the exhaust gas of the combustion type heater 17 and the air-fuel ratio of the combustion type heater 17 are adjusted.
[0059]
(Operation control execution routine of combustion type heater 17)
Next, an operation control execution routine of the combustion heater 17 will be described with reference to FIGS.
[0060]
This routine is a part of a normal flowchart (not shown) for driving the engine 1 and includes steps S101 to S117 described below. The flowchart including these steps is stored in the ROM of the ECU 46. The flowchart according to the second embodiment is also a part of a normal flowchart (not shown) for driving the engine 1, and is also stored in the ROM of the ECU 46. The processing in each step of each flowchart is entirely performed by the CPU of the ECU 46.
[0061]
Although FIGS. 5 and 6 should normally be collectively shown on the same paper, they are separated by the space of the paper. The symbols of (1) and (2) shown in FIG. 4 and the symbols of (1) and (2) shown in FIG. 5 correspond to the same symbols, and the destination of the process is guided by these symbols. . 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. 5 means continue. Further, symbols such as (1) in which a circle is attached to the number, which guides the destination of the process, such as (1), have the same meaning even in the flowchart of the operation control routine of the combustion type heater according to the second embodiment. Have. Note that the symbol S is used, and for example, if it is step 101, it is abbreviated as S101.
[0062]
After the start of the engine 1, when the process proceeds to this routine, it is first determined in S101 whether or not the ignition control start flag has been set, that is, whether or not the engine 1 is in an operating state in which the combustion heater 17 needs to be activated. . The operating state in which the combustion type heater 17 needs to be activated includes, for example, when the engine 1 is operating in cold or extreme cold, after starting the internal combustion engine, when the calorific value of the internal combustion engine itself is small, and when the internal combustion engine itself is low. Are small when the amount of heat received by the engine cooling water is small due to the small amount of heat generated, and when the machine is warmed up immediately after starting at room temperature. Therefore, in this case, the temperature of the engine cooling water is naturally low, and the case where the temperature of the engine cooling water is lower than a predetermined temperature, for example, 60 ° C., is regarded as the case where the combustion type heater 17 needs to be activated. The temperature of the engine cooling water is detected by a water temperature sensor 47 relating to a water jacket of the engine body 3. If an affirmative determination is made in S101, in S102, the valve body 44a of the valve device 44 of the communication path 36 is driven by the drive motor 44b to operate the opening / closing mechanism 44c to fully open. As a result, the air supply pipe 33 and the combustion gas discharge pipe 35 directly communicate with each other via the communication passage 36, that is, communicate with each other.
[0063]
Further, when the temperature of the engine cooling water is higher than the predetermined temperature exemplified as 60 ° C., it means that the engine 1 is in an operating state in which the combustion type heater 17 does not need to be activated, so a negative determination is made in S101, This routine ends.
[0064]
In S103, whether or not the actual elapsed time Tm1 from the start of energization to the glow plug 17g is larger than 0 (zero) is determined using an inequality equation. That is, if the elapsed time Tm1> 0, the determination is affirmative and the process proceeds to S104. Otherwise, a negative determination is made and the process proceeds to S105. The determination in S103 is also a step of determining whether the first energization has been performed on the glow plug 17g. That is, a negative determination in S103 means that the glow plug 17g has not been energized yet, so the elapsed time Tm1 from the start of energization to the glow plug 17g is always zero. Therefore, a negative determination is made and the process proceeds to S105, where energization of the glow plug 17g is started. Further, in S105, since the battery runs out forever if the glow plug 17g is energized, the energization is stopped when a predetermined time has elapsed after the first energization start (hereinafter referred to as "glow OFF"). Then, the process proceeds to S106. Note that, for the sake of simplicity, the step of performing glow OFF control processing is omitted.
[0065]
In S106, the elapsed time Tm1 from the start of the first energization to the glow plug 17g is counted.
[0066]
The story returns to S103 once. When the determination is affirmative in S103, it indicates the case of the second and subsequent routines in which the ignition control start flag has been set. More specifically, after a negative determination is made in step S103 that the glow plug 17g has been energized, that is, after the glow plug 17g has been energized once and the actual elapsed time Tm1 from the start of energization of the glow plug 17g has been counted by the timer Tim. This is the case of the second and subsequent routines. Therefore, the time Tm1 actually counted from the start of energization to the glow plug 17g is always a numerical value larger than 0. Therefore, in S103, an affirmative determination is made in this case, and the process proceeds to the next S104.
[0067]
In S104, the current supply to the glow plug 17g is continued until the time of the glow OFF, and then the process proceeds to S106.
[0068]
In S107, it is determined whether or not the elapsed time Tm1 counted in S106 has exceeded a predetermined time T1 which is a measure for executing the operation control of the fuel pump, using an inequality including an equal sign. That is, when the elapsed time Tm1 ≧ the predetermined time T1, the determination is affirmative and the process proceeds to the next step S108, and when the determination is negative, the routine ends.
[0069]
In S108, the fuel pump is operated to reduce the amount of liquefied fuel sent from the fuel supply pipe 17e to the fuel vaporization unit 17f. First of all, it is enough to secure the amount of fuel required to make the fire.
[0070]
In S109, the blower fan 45 is operated with the output reduced. This is to make it easy to make fire.
[0071]
In S110 (S109), the output value of the ion sensor 17h as the ignition sensor is read.
[0072]
In S111 (s110), it is determined based on the output value of the ion sensor 17h in S110 whether ignition has been completed, that is, whether or not a fire has been generated. It is determined whether a fire has been generated based on whether the output value in S110 is larger or smaller than a specific predetermined value. The process proceeds to the next step S112 if the confirmation of the securing of the fire type is made, and proceeds to S116 if the determination of the non-secure of the fire type is made. In the case of the combustion type heater 17, in order to ensure that the fire can be grown into a flame once the fire is secured, the fire made in S111 is a fire of a size large enough to respond to it. I do.
[0073]
In S112 (S111), the valve body 44a of the valve device 44 in the communication path 36 is driven by the drive motor 44b to operate the opening / closing mechanism 44c and is fully closed. As a result, the air supply pipe 33 and the combustion gas discharge pipe 35 do not flow directly through the communication path 36.
[0074]
In the next S113, the output of the blower fan 45 is increased to further increase the amount of air flowing to the combustion chamber 17d. Since a fire has already been formed at this time, and since this fire is a fire of a size large enough to surely grow into a flame, the output of the blower fan 45 is increased to reduce the amount of air flowing to the combustion chamber 17d. Even if it increases, there is no fear that the fire will go out.
[0075]
In S114, the fuel pump is operated to increase the amount of liquefied fuel sent from the fuel supply pipe 17e to the fuel vaporization unit 17f. This is to make the fire grow into a flame.
In S115, the ignition control start flag is reset in preparation for the next operation control execution routine of the combustion type heater 17.
[0076]
The process returns to S111. If a negative determination is made in S111 and the operation proceeds to S116, the operation of the fuel pump is stopped, and the operation proceeds to S117. Even if fuel is supplied in a state where there is no fire, the amount of fuel supplied is too large relative to the amount of air inside the combustion type heater, and the air-fuel ratio of the combustion type heater 17 becomes a so-called excessively rich state. In this case, there is a possibility that a harmful effect such as the emission of white smoke due to the vaporization of the fuel or the odor of raw gas due to the generation of unburned hydrocarbons may be caused. . After S116, the process proceeds to S117.
[0077]
In S117, the blower fan 45 is operated to scavenge the inside of the combustion chamber 17d of the combustion type heater 17, that is, to sweep out excess fuel from the combustion chamber 17d. Then, after the end of the scavenging, the operation of the blower fan 45 is stopped, and this routine ends. The reason why the operation of the blower fan 45 is stopped is that there is no point in keeping the blower fan 45 rotating even after the scavenging is completed.
[0078]
The above is the description of the engine 1 having the combustion heater 17 according to the first embodiment of the present invention.
[0079]
<Operation and Effect of First Embodiment>
Next, the operation and effect of the first embodiment will be described.
[0080]
The engine 1 includes a communication path 36 that connects the air supply pipe 33 and the combustion gas discharge pipe 35, and the communication path 36 circulates air between the air supply pipe 33 and the combustion gas discharge pipe 35. is there. Therefore, when the air flowing through the air supply pipe 33 reaches a portion connected to the communication passage 36, the air branches there into the air flowing through the communication passage 36 and the air flowing toward the combustion heater 17. The communication passage 36 is open when the valve element 44a of the valve device 44 provided therein starts ignition by the glow plug 17g. For this reason, even if the energetic air flows toward the combustion type heater 17, at least at the start of ignition of the combustion type heater 17, that is, when the glow plug 17g generates heat by energization, the energetic air is supplied to the communication passage. The fuel gas flows out to the combustion gas discharge pipe 35 through 36, and its momentum is attenuated. That is, if the amount of opening of the communication passage 36 is made sufficiently large depending on the degree of opening of the valve body 44a, the amount of air flowing toward the combustion type heater 17 is sufficiently reduced or reduced to zero (0) so that ignition by the combustion type heater 17 can be reliably performed. Zero). Therefore, strong ventilation that cannot ignite is not generated in the combustion chamber 17 d of the combustion heater 17. As a result, since strong wind does not flow in the air flow passage, ignition of the combustion heater can be reliably performed at once. In addition, the generation of unpleasant odors caused by the generation of white smoke and unburned hydrocarbons can be prevented.
[0081]
Further, the combustion heater 17 has an ion sensor 17h as an ignition sensor for detecting whether or not the fuel for combustion is ignited by a glow plug 17g as an ignition means. When the ignition is detected by the ion sensor 17h, the ion sensor The output value of 17h is input to the CPU, and when the CPU determines that the combustion fuel has been ignited, that is, that the ignition type has been secured, based on the output value, the valve device 44 is closed. Then, the air that has flowed out to the combustion gas discharge pipe 35 through the communication passage 36 returns to the air supply pipe 33, so that the amount of air flowing through the combustion chamber 17d of the combustion heater 17 increases, and further, the blowing fan 45 In combination with the increase in the amount of circulating air due to the operation of, the fire eventually grows into a flame. In addition, increasing the amount of circulating air is not enough to grow a fire into a flame, and it is necessary to supply fuel using a fuel pump and a fuel supply pipe 17e that constitute fuel supply means. The fuel supply control is performed by the CPU, and the CPU restricts the fuel supply amount before ignition detection by the ion sensor 17h, and releases the fuel supply amount restriction after ignition detection.
[0082]
As described above, in the combustion type heater 17, the presence of a fire is confirmed by the CPU's determination based on the detection of the ion sensor 17h, and after confirming that ignition has been completed, the amount of air flowing through the combustion chamber 17d is increased. , It is possible to surely make the fire grow into a flame.
[0083]
Further, in the combustion heater 17, the CPU limits the fuel supply amount before ignition detection by the ion sensor 17h, and releases the fuel supply amount restriction after ignition detection. Therefore, the fuel supply amount increases only after ignition detection, that is, when the securing of the kind of fire is ensured, so that prevention of generation of white smoke and generation of unpleasant odor caused by generation of unburned hydrocarbons are more reliably prevented. Can be done.
[0084]
<Second embodiment>
The second embodiment will be described with reference to FIGS.
[0085]
The difference between the combustion type heater 17 according to the second embodiment and the combustion type heater 17 according to the first embodiment is that (1) according to the first embodiment as shown in FIG. (2) The valve device 44 according to the first embodiment is eliminated, and a valve device corresponding to the valve device, wherein the combustion gas from the combustion heater 17 to the combustion gas discharge pipe 35 is provided. Providing a valve device 44 'as means for reducing the amount of combustion gas for reducing the amount of exhaust gas, (3) the supply route of fresh air to the combustion type heater 17, and (4) the contents of the operation control execution routine of the combustion type heater 17. It is. Therefore, only different parts from the first embodiment will be described.
[0086]
(Air supply pipe 33 ')
The air supply pipe 33 ′ corresponds to the air supply pipe 33 according to the first embodiment, but the air supply pipe 33 ′ is configured to take in air directly from the atmosphere instead of the main pipe 29. I have. Therefore, the air passing through the air supply pipe 33 ′ becomes outside air A, and the outside air A becomes the combustion gas a 2 by the combustion of the combustion heater 17 and flows to the combustion gas discharge pipe 35.
[0087]
(Valve device 44 ')
The valve device 44 'according to the second embodiment is attached to a portion of the combustion gas discharge pipe 35 from the combustion heater 17, and the valve device 44 according to the first embodiment and its constituent members Are substantially the same. Therefore, the components of the valve device 44 'according to the second embodiment are denoted by the same reference numerals as those of the components of the valve device 44 according to the first embodiment, and description thereof is omitted.
[0088]
(Operation control routine of combustion type heater 17)
Next, an operation control routine of the combustion heater 17 according to the second embodiment will be described with reference to FIGS.
[0089]
The flowchart according to the second embodiment includes steps S201 to S215 described below. Also, S201 to S208 except S202 correspond to S101 to S108 except S102 in the flowchart of the operation control routine of the combustion heater 17 according to the first embodiment, and are substantially the same. The description of them will be omitted, and the description of S202 and the description of S209 and thereafter will be made.
[0090]
In S202, the valve body 44a of the valve device 44 'for the combustion heater 17 is closed. Thereby, the flow of the combustion gas flowing through the combustion gas discharge pipe 35 is suppressed, and the amount of the combustion gas is reduced.
[0091]
When the process proceeds to S209 via S201 to S208, the output value of the ion sensor 17h is read in S209.
[0092]
In S210, it is determined based on the output value of S209 whether ignition has been completed, that is, whether or not a fire has been generated. It is determined whether a fire has been generated based on whether the output value in S209 is larger or smaller than a specific predetermined value. The process proceeds to the next step S211 if the confirmation of the securing of the fire type is made, and proceeds to S215 if the determination of the non-secure of the fire type is made. Further, in the combustion type heater 17 according to the present invention, in order to surely grow the flame when the fire type is secured, the fire type formed in this step is a fire type large enough to respond to it.
[0093]
In S211, the valve body 44a of the valve device 44 'of the combustion heater 17 is fully opened, and the amount of combustion gas discharged from the combustion heater 17 is increased.
[0094]
In the next S212, the output of the blower fan 45 is increased to increase the amount of air flowing in the combustion type heater 17, that is, in the combustion chamber 17d. This is because a fire has already been generated at this stage, so that even if the output of the blower fan 45 is increased to increase the amount of air flowing through the combustion chamber 17d, the fire does not disappear.
[0095]
In S213, the fuel pump is operated to increase the amount of liquefied fuel sent from the fuel supply pipe 17e to the fuel vaporization unit 17f. This is to make the fire grow into a flame.
In S214, the ignition control start flag is reset in preparation for the next operation control execution routine of the combustion type heater 17.
[0096]
Return to S210. If a negative determination is made in S210 and the process proceeds to S215, the blower fan 45 is stopped or its output is reduced, and then this routine is stopped. This is because it is not necessary to increase the output of the blower fan 45 even if a fire has not occurred.
[0097]
<Operation and Effect of Second Embodiment>
Next, the operation and effect of the second embodiment will be described.
[0098]
The combustion heater 17 is provided with a valve device 44 'for controlling the amount of air flowing through the combustion chamber 17d in the combustion gas exhaust pipe 35, and the flow of the combustion gas in the combustion gas exhaust pipe 35 is suppressed by the valve device 44'. Therefore, the amount of air flowing through the combustion chamber 17d can be suppressed. Therefore, at least when the combustion type heater 17 starts ignition, if the amount of air flowing through the combustion chamber 17d is reduced or reduced to 0 (zero) enough to generate a kind of ignition by the above-described suppression, the momentum is so high that ignition is not possible. There is no danger of generating strong wind in the combustion chamber 17d. Therefore, since strong wind does not occur in the combustion chamber 17d, the ignition of the combustion heater 17 can be reliably performed at once. In addition, since ignition is reliable, not only generation of white smoke can be prevented, but also generation of unpleasant odor due to generation of unburned hydrocarbons can be sufficiently prevented.
[0099]
When the combustion heater 17 is not operated, the valve body 44a of the valve device 44 'is closed to prevent foreign matters such as mud and water from entering the combustion heater 17.
[0100]
In this embodiment, the valve device is provided in the combustion gas discharge pipe 35. However, the valve device may be provided in the air supply pipe 33. Alternatively, the valve device may be provided in the combustion gas discharge pipe 35 and the air supply pipe 33. Both may be provided with a valve device 44 '. In this case, it is also possible to improve the ignitability by closing the respective valve bodies 44a of the two valve devices 44 'and 44' only during the ignition control and extremely reducing the differential pressure in the combustion chamber 17d during the ignition. Further, by closing the valve bodies 44a of both the valve devices 44 'and 44', the effect of preventing foreign matter from entering the combustion heater 17 can be enhanced.
[0101]
【The invention's effect】
As described above, in the internal combustion engine having the combustion heater according to the present invention, since the ventilation that is not strong enough to ignite when the combustion heater is ignited does not occur in the combustion chamber of the combustion heater, the combustion heater is ignited. Can be performed reliably. Further, since ignition is reliable, not only generation of white smoke can be prevented, but also generation of unpleasant odor due to generation of unburned hydrocarbons can be prevented.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an internal combustion engine having a combustion heater according to a first embodiment of the present invention.
FIG. 2 is a schematic sectional view of a combustion heater according to the embodiment of the present invention.
FIG. 3 is a cross-sectional view taken along a virtual cross section including line III-III in FIG. 2 and viewed in a direction indicated by an arrow;
FIG. 4 is an enlarged view of a main part of FIG. 1;
FIG. 5 is a part of a flowchart constituting an operation control execution routine of a combustion heater according to the first embodiment of the present invention;
FIG. 6 is a part of a flowchart that constitutes an operation control execution routine of the combustion heater according to the first embodiment of the present invention and that is continuous with FIG.
FIG. 7 is a schematic configuration diagram of an internal combustion engine having a combustion heater according to a second embodiment of the present invention.
FIG. 8 is a schematic sectional view of a combustion heater according to a second embodiment of the present invention.
FIG. 9 is a part of a flowchart constituting an operation control execution routine of a combustion type heater according to a second embodiment of the present invention.
FIG. 10 is a part of a flowchart which constitutes a combustion heater operation control execution routine according to a second embodiment of the present invention and is continuous to FIG. 9;
[Explanation of symbols]
1. Engine (internal combustion engine)
3. Engine body (body of internal combustion engine)
5. Intake device
7 Exhaust device
9 ... Heater for vehicle compartment
13 ... Air cleaner
15 ... Turbocharger
15a ... Compressor
15b: Turbocharger turbine
17. Combustion heater
17a: Engine cooling water passage of combustion type heater
17a1 Engine cooling water inlet
17a2: Engine cooling water outlet
17b: Combustion cylinder (combustion chamber)
17c ... cylindrical partition
17d: Combustion chamber
17d1… Air supply port
17d2 ... Exhaust exhaust port
17e: fuel supply pipe (fuel supply means)
17f: Fuel vaporization section
17g ... glow plug (ignition means)
17h ... Ion sensor (ignition detection means)
17i: Fuel heating evaporation plate
18. Liquefied fuel
18 '... Vaporized fuel
19. Intercooler
21 ... intake manifold
23 ... intake pipe
25 ... upstream connecting pipe
27… Downstream connecting pipe
29… Main tube
31 ... Branch for heater (air flow passage)
32 ... Outside air temperature sensor
33 ... Air supply pipe (air supply path)
35: combustion gas discharge pipe (combustion gas discharge path)
36 ... Connecting pipe (tube body)
38… Exhaust manifold
39 ... catalytic converter
41 ... Muffler
42 ... exhaust pipe
43a ... outer wall
44 ... Valve device (communication passage opening / closing means)
44 '... valve device
44a ... Valve (throttle valve)
44b Drive motor
44c: Opening / closing mechanism
45… Blower fan
46 ... ECU
47… Water temperature sensor
W1 ... Water pipeline
W2: Water pipeline
W3: Water pipeline
F ... Flame
F '… Fire
Tim: Timer
A: Outside air entering the main pipe 29 from the air cleaner 13
a1 ... Air diverging from outside air A at connection point c1 and flowing through air supply pipe 33 (fresh air)
a1 '... air flowing through the main pipe 29 toward the connection point c2
a2: Combustion gas of combustion type heater 17
a3 ... Air mixed with combustion gas of air a2 and air a1 '
a4: Exhaust gas of engine 1
c1: Connection point between the air supply pipe 33 and the main pipe 29
c2: connection point between the combustion gas discharge passage 35 and the main pipe 29

Claims (6)

An internal combustion engine having a combustion-type heater that operates when the internal combustion engine is in a predetermined operating state to increase the temperature of an engine-related element,
Ignition means for igniting the fuel for combustion used in the combustion type heater to create an ignition source,
A combustion chamber, which is a room for growing the type of fire produced by the ignition means into a flame,
An air supply passage for supplying combustion air to the combustion chamber,
A combustion gas discharge passage for discharging combustion gas from the combustion chamber;
A pipe connecting the air supply path and the combustion gas discharge path,
An internal combustion engine having a combustion-type heater including a blower fan provided downstream of a connection portion between the air supply path and the tube in the air flow direction of the air supply path. 2. The combustion type according to claim 1 , wherein the pipe body is a communication path that opens when starting ignition by the ignition means and communicates between the air supply path and the combustion gas discharge path. 3. An internal combustion engine having a heater. The internal combustion engine having a combustion type heater according to claim 2 , wherein the communication path is closed after ignition by the ignition means is completed. 4. The internal combustion engine having a combustion heater according to claim 2 , wherein the communication path includes communication path opening / closing means. An internal combustion engine having a combustion-type heater that operates when the internal combustion engine is in a predetermined operating state to increase the temperature of an engine-related element,
Ignition means for igniting the fuel for combustion used in the combustion type heater to create an ignition source,
A combustion chamber, which is a room for growing the type of fire produced by the ignition means into a flame,
An air supply passage for supplying combustion air from the atmosphere to the combustion chamber,
A combustion gas discharge passage for discharging combustion gas from the combustion chamber;
An internal combustion engine having a combustion-type heater provided in the combustion gas discharge path and having a combustion gas amount reduction means for reducing the amount of combustion gas flowing through the combustion gas discharge path at the start of ignition by the ignition means. The internal combustion engine having a combustion heater according to claim 5 , wherein the combustion gas amount reducing means is a throttle valve that narrows the combustion gas discharge path.

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