JP3539255B2 - Internal combustion engine with supercharger - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an internal combustion engine that includes a combustion heater that raises the temperature of an engine-related element and has a supercharger. More specifically, the present invention relates to a technique for using combustion gas of a combustion heater.
[0002]
[Prior art]
In recent years, internal combustion engines have high thermal efficiencies, such as direct injection engines and diesel engines, for example, and the amount of excess heat discharged is small. Therefore, a combustion-type heater is provided separately from the internal combustion engine to heat engine-related elements such as a heater core when the engine is started.
[0003]
Since such a combustion type heater is provided, it is desired to use the exhausted combustion gas efficiently.
As an example of using a combustion gas of a combustion heater, an example described in Japanese Patent Application Laid-Open No. 60-78819 is known.
[0004]
This is a structure in which a combustion-type heater for supplying heating air to a vehicle compartment is provided, and an exhaust port of the combustion-type heater is provided upstream of an exhaust purification device of an exhaust pipe.
On the other hand, there is known an internal combustion engine having a turbocharger that supercharges intake air by rotating a compressor provided in an intake system by a turbine provided in an exhaust system of the internal combustion engine.
[0005]
[Problems to be solved by the invention]
By the way, when the internal combustion engine is started, the supercharging pressure of the turbocharger is not large because the exhaust pressure is not large. Therefore, since the intake air amount is not large, it is difficult to say that the startability of the internal combustion engine is good.
[0006]
Further, even in such an internal combustion engine equipped with a turbocharger, even if the above-described combustion type heater is provided, there has been no example of finding any relationship between the turbocharger and the combustion type heater.
[0007]
Under such a background, an object of the present invention is to improve the startability of an internal combustion engine by effectively using the combustion gas of a combustion heater.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the following means has been adopted for an internal combustion engine having a supercharger of the present invention.
[0009]
That is, the internal combustion engine of the present invention is provided in the intake system with a combustion heater provided to raise the temperature of the engine-related elements by the heat obtained by burning the fuel, and a turbine provided in the exhaust system of the internal combustion engine. An internal combustion engine provided with a supercharger that supercharges intake air by rotating a compressor that is driven at the time of starting the internal combustion engine, that is, at the time of cranking, by flowing combustion gas of a combustion type heater to an exhaust system, and forming a turbine of the supercharger Is used as a power source for rotating the compressor, thereby performing supercharging by a compressor.
[0010]
More specifically, the configuration of the present invention includes a combustion type heater provided to raise the temperature of an engine-related element by heat obtained by burning fuel, and a turbine provided in an exhaust pipe of an internal combustion engine. By rotating, a supercharger that rotates a compressor provided in an intake pipe to supercharge intake air, and guides combustion gas of the combustion heater to a turbine of the supercharger when the internal combustion engine is cranked. And a combustion gas supply means.
[0011]
Here, further, a variable nozzle that is provided in the turbine of the supercharger and that can be opened and closed to increase the rotation speed of the turbine when closed and to increase the supercharging pressure by the compressor, and when the combustion gas is supplied by the combustion gas supply means, Preferably, a variable nozzle control means for closing the variable nozzle of the turbine is provided. When the variable nozzle is closed, the turbine rotates faster because the exhaust gas concentrates on the turbine and its flow velocity increases. As a result, the compressor rotates at a high speed, and the supercharging pressure is further increased. As a result, the startability of the internal combustion engine becomes better.
[0012]
According to the present invention, an EGR pipe which branches off from an exhaust pipe of the internal combustion engine and returns exhaust gas of the internal combustion engine to an intake pipe is provided, and the turbine of the supercharger is connected to an exhaust pipe downstream of a branch point to the EGR pipe. By rotating this turbine, the compressor provided in the intake pipe is rotated to supercharge the intake air. Further, when the internal combustion engine is cranked, the combustion gas of the combustion heater is supplied to the EGR pipe. And a combustion gas supply means for supplying to the exhaust pipe via
[0013]
That is, the combustion gas of the combustion heater is supplied to the turbine provided in the exhaust pipe using the EGR pipe.
Also in this case, it is preferable that the variable nozzle is provided in the turbine, and a variable nozzle control unit that closes the variable nozzle of the turbine when the combustion gas is supplied by the combustion gas supply unit is provided.
[0014]
Further, a combustion gas exhaust pipe is provided with a catalyst for purifying exhaust gas exhausted from the internal combustion engine on the exhaust pipe, and introducing combustion gas from a combustion type heater into an exhaust pipe located downstream of the catalyst. A first route for guiding the combustion gas discharged from the combustion type heater to an exhaust pipe on the upstream side of the catalyst via an EGR pipe; and a combustion gas discharged from the combustion type heater to a combustion gas. An exhaust switching valve may be provided to selectively switch between a second route introduced into an exhaust pipe located downstream of the catalyst via the exhaust pipe.
[0015]
Before or at the time of starting the internal combustion engine, if the first route is selected by the exhaust gas switching valve and the combustion gas of the combustion type heater is introduced from the EGR pipe to the upstream side of the catalyst, the temperature of the catalyst is raised and the exhaust purification action is performed. It is possible to make full use of it when starting the engine. On the other hand, when the catalyst temperature is excessively heated, if the second route is selected by the exhaust gas switching valve, the combustion gas of the combustion heater can be discharged to the downstream side of the catalyst, so that the catalyst temperature becomes excessively high. The problem of increased sulfate can be avoided.
[0016]
Here, the internal combustion engine means not only a normal port injection gasoline engine but also a gasoline direct injection lean burn engine, a diesel engine or a CNG (compressed natural gas) engine, and the atmosphere in the exhaust system is excessive in oxygen and Includes internal combustion engines low in hydrocarbons and carbon monoxide.
[0017]
The combustion type heater is a heater attached to the internal combustion engine as a separate product from the internal combustion engine body, and performs a unique combustion without being affected by the combustion in the cylinder of the internal combustion engine body and discharges combustion gas. It is. Since it is necessary to raise the temperature of the engine-related elements before the engine is started, it is provided separately from the internal combustion engine body.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of an internal combustion engine having a supercharger according to the present invention will be described with reference to FIGS.
[0019]
FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine according to the present embodiment. The internal combustion engine shown in FIG. 1 is a multi-cylinder water-cooled diesel engine.
The diesel engine has an engine main body 1 having a water jacket containing engine cooling water, an intake device 2 for feeding air required for combustion into a plurality of cylinders of the engine main body 1, and an exhaust gas after the air-fuel mixture is burned. It has an exhaust device 3 for discharging into the inside and a heater core 4 of a heating device for warming the interior of the vehicle equipped with the engine.
[0020]
The intake device 2 includes an air cleaner 5 that filters intake air, a compressor 6a of a turbocharger 6 that pumps intake air that has passed through the air cleaner 5, and intake air that has been heated by heat generated when compressed by the compressor 6a. An intercooler 7 for cooling and an intake manifold 8 for sending intake air passing through the intercooler 7 to each cylinder of the engine body 1 are connected to each other by an intake pipe 9. Further, an intake throttle valve 11 is arranged between the intercooler 7 and the engine body 1.
[0021]
The exhaust device 3 includes an exhaust manifold 12 connected to an exhaust port of the engine body 1, a turbine 6b of the turbocharger 6, an exhaust purification catalyst 13 for purifying exhaust gas, and a muffler (not shown) connected to the catalyst 13. Are provided on the exhaust pipe 14. In this example, the exhaust purification catalyst 13 includes a NOx catalyst 13a on the upstream side and an oxidation catalyst 13b on the downstream side. As the NOx catalyst, a selective reduction type lean NOx catalyst and a storage reduction type lean NOx catalyst can be exemplified.
[0022]
The selective reduction type lean NOx catalyst is a catalyst that reduces or decomposes NOx in an oxygen-excess atmosphere (lean atmosphere) and in the presence of hydrocarbons (HC). And a catalyst in which a noble metal is supported on zeolite or alumina. In the selective reduction type NOx catalyst, the catalyst bed temperature is in the catalyst purification window, the air-fuel ratio of the inflowing exhaust gas is a lean atmosphere, and HC in the exhaust gas, preferably HC which has been thermally decomposed to have a reduced molecular size. Is present, a part of HC is partially oxidized to generate active species, and the active species reacts with NOx in the exhaust gas to reduce NOx to N ₂ , H ₂ O, CO _{2, and the} like. .
[0023]
The storage-reduction type lean NOx catalyst uses, for example, alumina as a carrier, and on the carrier, for example, alkali metals such as potassium K, sodium Na, lithium Li, cesium Cs, alkaline earths such as barium Ba, calcium Ca, and lanthanum La. , And at least one selected from rare earths such as yttrium Y and a noble metal such as platinum Pt. When the ratio of air and fuel (hydrocarbon) supplied to the engine intake passage and the exhaust passage upstream of the NOx catalyst is referred to as the air-fuel ratio of the exhaust gas flowing into the NOx catalyst, the NOx catalyst generates When the fuel ratio is lean, NOx is absorbed, and when the oxygen concentration in the inflowing exhaust gas decreases, the absorbed NOx is released.
[0024]
The oxidizing catalyst oxidizes components of the reducing agent (fuel in the case of diesel) that have not been consumed, that is, components such as HC and CO, and discharges them as CO ₂ and water.
[0025]
The selective reduction type lean NOx catalyst exhibits a purification ability when the catalyst bed temperature is within a predetermined temperature range (catalyst purification window), but this is the same for the occlusion reduction type lean NOx catalyst and the oxidation catalyst. is there. FIG. 2 shows the relationship between the temperature of the exhaust gas entering the catalyst and the NOx purification rate. From this figure, it can be understood that the NOx purification rate is high, for example, between 160 ° C. and 300 ° C.
[0026]
Further, the engine body 1 is provided with an exhaust gas recirculation device (EGR) for lowering the combustion temperature and reducing NOx in the exhaust gas by returning a part of the exhaust gas to the intake system. The EGR includes an EGR pipe 20 that connects the exhaust manifold 12 as the exhaust pipe 14 and the intake manifold 8 of the intake pipe 9.
[0027]
The EGR pipe 20 is provided with an EGR valve 21 for controlling the amount of gas flowing therethrough. The EGR valve 21 is electrically connected to the ECU 18. The EGR valve 21 opens as a command of the ECU 18 during steady operation of the engine, so that the EGR device functions as an exhaust gas recirculation device. The EGR valve 21 is opened when the combustion type heater 22 is operating in a stop state before the engine is started, so that the combustion gas emitted by the combustion type heater 22 is supplied through the EGR pipe 20 to the intake pipe. 9 to the exhaust pipe 14. As described above, even when the engine is stopped, the combustion gas from the combustion heater flows through the existing EGR pipe 20 to the catalyst 13 on the exhaust pipe 14, so that when the engine starts, the catalyst 13 Has reached a temperature at which it can function effectively. Therefore, after the engine is started, the purification performance of the catalyst 13 can be sufficiently improved. In addition, since the existing EGR pipe 20 is used, the structure is simple and the cost can be reduced.
[0028]
Further, a turbine 6 b of the turbocharger 6 is provided on the exhaust pipe 14 downstream of the branch point to the EGR pipe 20 and upstream of the catalyst 13.
As shown in FIG. 3, the turbocharger 6 has a variable nozzle vane 62 in the turbine 6b. FIG. 4 shows the details of the variable nozzle vane 62. In FIG. 4, reference numeral 61 denotes a turbine wheel. A nozzle vane (variable) whose opening is variable is provided at a turbine inlet for guiding exhaust gas to the turbine wheel 61. Nozzle) 62 is provided.
[0029]
In this embodiment, the opening degree of the nozzle vane 62 is adjusted by transmitting the rotation of the drive ring 63 via the link 64, and the drive ring 63 is connected to the actuator 65 driven by air pressure. It is connected to a rod 66. In FIG. 4, when the rod 66 is operated to the left, the opening of the nozzle vane 62 becomes large, and when the rod 66 is operated to the right, the opening of the nozzle vane 62 becomes small.
[0030]
The actuator 65 is formed with two diaphragm chambers 69 and 70 separated by diaphragms 67 and 68. The diaphragms 67 and 68 are connected to the rod 66, respectively. The diaphragms 67 and 68 are biased to one side by springs 71 and 72, respectively. Reference numeral 73 denotes a bellows for preventing air from leaking from the rod 66.
[0031]
The inlet ports 74, 75 of the diaphragm chambers 69, 70 are connected to electric vacuum regulating valves (hereinafter, EVRV) 76, 77, respectively, and the EVRVs 76, 77 are connected to a vacuum pump 78 as a negative pressure source. ing. Further, the EVRVs 76 and 77 are connected to the ECU 18, and based on a signal from the ECU 18, reduce the negative pressure introduced into the diaphragm chambers 69 and 70 with the negative pressure from the vacuum pump 78 and the atmosphere ports 80 and 81. Switch to atmospheric pressure. In the present embodiment, the intermediate operating position of the actuator 65, that is, the operating position when the atmospheric pressure is simultaneously introduced into the diaphragm chambers 69 and 70 or when the same negative pressure is simultaneously introduced is determined by the opening degree of the nozzle vane 62. Is in an operating position such that the opening degree is an intermediate opening between the fully opened state and the fully closed state.
[0032]
Then, when the engine is started, when the negative pressure is introduced into the diaphragm chamber 70 by turning on the EVRV 77 and turning off the EVRV 76, the rod 66 advances rightward in FIG. 4 and the nozzle vane 62 closes. Then, the gas flowing through the exhaust pipe 14 concentrates on the turbine 6b, and the rotation speed of the turbine 6b is increased. As a result, the rotation speed of the compressor 6a is also increased, so that the intake air is supercharged and the startability of the engine is improved. I do.
Next, the combustion type heater 22 will be described.
[0033]
As shown in FIG. 1, a branch pipe 31 for a heater is provided branching from an intake pipe 9 connecting the air cleaner 5 and the compressor 6 a of the turbocharger 6, and a combustion type heater 22 is provided on the branch pipe 31 for the heater. It is connected.
[0034]
The combustion heater 22 heats a heat medium (cooling water) with heat generated by burning fuel separately from the engine, and circulates the heater core 4 and the engine body 1 using the heat medium as an engine-related element. The resulting heat exchange heats these engine-related elements. Therefore, a heat medium circulation path is provided for circulating a heat medium (cooling water) from the combustion heater 22 via the heater core 4 and the water jacket of the engine body 1.
[0035]
As such a heat medium circulation path, the combustion type heater 22 includes a cooling water introduction passage 32 that guides engine cooling water to the combustion type heater 22, and a heater core 4 that supplies the cooling water heated in the combustion type heater 22. A cooling water discharge passage 33 that leads to the engine main body 1 via the cooling water discharge passage 33 is connected.
[0036]
Here, a specific configuration of the combustion heater 22 will be described with reference to FIG. Inside the combustion type heater 22, a heater internal cooling water passage 22 a communicating with a cooling water introduction passage 32 and a cooling water discharge passage 33 is formed for flowing cooling water from the water jacket.
[0037]
The heater internal cooling water passage 22a is arranged to circulate around a combustion chamber 22d formed inside the combustion type heater 22, and cooling water flowing in the heater internal cooling water passage 22a receives heat from the combustion chamber 22d. To increase the temperature.
[0038]
The combustion chamber 22d includes a combustion tube 22b as a combustion source for generating a flame, and a cylindrical partition wall 22c that covers the combustion tube 22b to prevent the flame from leaking to the outside. By covering the combustion cylinder 22b with the partition 22c in this way, the combustion chamber 22d is defined inside the partition 22c. The partition wall 22c is covered by the outer wall 24 of the combustion type heater 22. An annular gap is provided between the partition wall 22c and the outer wall 24, and this gap functions as the above-described heater internal cooling water passage 22a.
[0039]
The combustion heater 22 has an air supply port 22e and an exhaust discharge port 22f, and the air supply port 22e and the exhaust discharge port 22f communicate with the combustion chamber 22d. The heater branch pipe 31 is connected to the air supply port 22e for introducing the intake air, and the exhaust discharge port 22f is connected to the intake pipe 9. The combustion gas discharged from the exhaust outlet 22f is introduced into the exhaust pipe 14 via the intake pipe 9 and the EGR pipe 20.
[0040]
A fuel introduction passage 25 is connected to the combustion cylinder 22b, and a part of the fuel discharged from the fuel pump 16 is supplied to the combustion cylinder 22b. Further, a vaporizing glow plug (not shown) for vaporizing the fuel supplied through the fuel introduction passage 25 and an ignition glow plug (not shown) for igniting the vaporized fuel are provided in the combustion cylinder 22b. It is decorated. The vaporizing glow plug and the ignition glow plug may be shared by a single glow plug.
[0041]
In the combustion type heater 22 configured as described above, the intake air flowing into the air supply port 22e from the heater branch pipe 31 is guided to the combustion chamber 22d, and the fuel supplied to the combustion cylinder 22b by the fuel introduction passage 25 is vaporized. Vaporized by glow plug. Then, the intake air and the vaporized fuel are mixed to form an air-fuel mixture, and the air-fuel mixture is ignited by an ignition glow plug in the combustion chamber 22d and burns.
[0042]
In addition, the combustion type heater 22 is configured to introduce the combustion gas generated by the combustion of the fuel into the exhaust pipe 14 through the intake pipe 9 and the EGR pipe 20 as described above. An exhaust switching valve 50 is provided at a connection point between the intake pipe 9, the exhaust outlet 22 f of the combustion heater, and the EGR pipe 20, as shown in FIG. There is provided a combustion gas discharge pipe 51 for introducing the combustion gas from the exhaust discharge port 22f to the exhaust pipe 14 located on the downstream side of the catalyst 13.
[0043]
The exhaust switching valve 50 is electrically connected to the ECU 18, and in accordance with a command from the ECU 18, the combustion gas from the exhaust outlet 22 f is catalyzed from the intake pipe 9 into the engine body 3 or via the EGR pipe 20. A first route leading to the exhaust pipe 14 on the upstream side and a second route introducing the combustion gas from the exhaust outlet 22f to the exhaust pipe 14 located downstream of the catalyst 13 via the combustion gas exhaust pipe 51. Are selectively switched.
[0044]
A water temperature sensor for detecting the engine water temperature (THW) and a temperature sensor for detecting the temperature of gas entering the catalyst at the inlet of the catalyst 13 are provided for switching the exhaust switching valve, or the catalyst temperature is detected in the catalyst. Temperature sensors are provided, and the temperatures detected by these sensors are transmitted to the ECU.
[0045]
The ECU 18 switches the exhaust switching valve 50 to select the first route or selects the second route based on one of the engine water temperature, the exhaust gas temperature, and the catalyst temperature sent from these sensors. A switching valve switching control means for determining whether to perform switching is realized.
[0046]
During warm-up before or after the start of the engine, when the exhaust gas switching valve 50 is selecting the first route, the combustion gas is guided through the EGR pipe 20 to the exhaust pipe 14 upstream of the NOx catalyst 13. . The combustion gas introduced into the exhaust pipe 14 flows into the NOx catalyst 13a via the turbine 6b. Therefore, the combustion gas rotates the turbine 6b and supercharges the intake air by the rotation of the compressor 6a accompanying the rotation. At this time, in order to increase the number of rotations of the turbine 6b, the nosle vane 62 is closed. Further, the heat of the combustion gas introduced into the catalyst 13 is transmitted to the NOx catalyst 13a, and the catalyst bed temperature of the NOx catalyst 13a rises.
[0047]
After the engine is started, exhaust gas is generated. The exhaust gas is included in the exhaust gas on condition that the catalyst bed temperature of the NOx catalyst 13a is already in the catalyst purification window and that sufficient oxygen exists in the exhaust gas. The HCs that have been partially oxidized to form active species, which react with NO _x in the exhaust gas to reduce NO _x to N ₂ , H ₂ O, CO _{2 and the} like.
[0048]
Further, in the combustion type heater 22, the heat generated by the combustion in the combustion chamber 22d is transmitted to the cooling water flowing in the heater internal cooling water passage 22a through the partition wall 22c to raise the temperature of the cooling water.
[0049]
After the start of the engine, when it is considered that the warm-up is completed due to the rise of the water temperature of the engine, the switching valve switching control means selects the second route. At this time, the combustion gas from the combustion type heater is discharged to the exhaust pipe 14 located downstream of the catalyst 13 via the combustion gas discharge pipe 51, and thereafter, the catalyst is not heated by the combustion gas and the exhaust gas is exhausted. Only heating of the catalyst. Therefore, the catalyst is not heated excessively to generate sulfate. Needless to say, when the second route is selected, fresh air is supplied from the intake pipe 9 to the engine body 3.
[0050]
Next, control of the exhaust gas switching valve according to the present embodiment will be described.
The control of the exhaust control valve according to the present embodiment is realized by executing a routine as shown in FIG. This exhaust switching valve control routine is a routine that is repeatedly executed at predetermined time intervals, including when the engine is cranked.
[0051]
First, initialization is performed in S101, and the engine water temperature and the engine speed detected by the water temperature sensor are taken in.
Next, in S102, it is determined whether the engine coolant temperature THW is lower than a predetermined temperature, for example, 20 ° C.
[0052]
Here, if the engine coolant temperature THW is higher than the predetermined temperature, the routine ends with the exhaust gas switching valve OFF and the variable nozzle open in S105. However, if the engine coolant temperature THW is lower than the predetermined temperature, the process proceeds to S103, and the engine speed is reduced. It is determined whether or not the number NE is lower than a predetermined rotation speed.
[0053]
If the engine rotational speed NE is higher than the predetermined rotational speed, the routine is terminated with the exhaust switching valve turned off and the variable nozzle opened in S105, but if lower, the exhaust switching valve is turned on and the first route is selected. At the same time, the nozzle vane 62 of the variable nozzle is closed. When the engine speed is low, the flow rate of the exhaust gas is also small. Therefore, by selecting the first route, the combustion gas from the combustion type heater 22 is introduced into the exhaust pipe 14 via the EGR pipe 20. Since the exhaust gas containing the combustion gas rotates the turbine 6b with the nozzle vanes 62 closed, the rotation speed of the turbine 6b increases, and the compressor 6a supercharges the intake air. Therefore, the starting performance of the engine is improved. Further, the combustion gas of the combustion type heater introduced into the exhaust pipe 14 through the EGR pipe 20 is introduced from the exhaust pipe 14 to the catalyst 13 and heats the catalyst, so that the activation of the catalyst is accelerated.
[0054]
When the warm-up is completed, the engine water temperature becomes higher than the predetermined temperature, so that a negative determination is made in S102. Then, in S105, the exhaust gas switching valve is turned off and the variable nozzle is returned to the open state. Therefore, the second route is selected, and the combustion gas of the combustion type heater is discharged via the combustion gas discharge pipe 51 to the exhaust pipe 14 located downstream of the catalyst 13. Is discharged. Therefore, thereafter, the catalyst is not heated by the combustion gas, and the catalyst is heated only by the exhaust gas.
[0055]
【The invention's effect】
According to the present invention, the intake gas can be supercharged by the supercharger at the time of starting the internal combustion engine using the combustion gas of the combustion type heater, so that the startability of the internal combustion engine can be improved.
[0056]
Further, if a turbine with a variable nozzle is used, the supercharging performance can be further improved.
Further, since the EGR pipe, which is an existing facility, is used to introduce the combustion gas of the combustion heater into the turbine of the supercharger, the configuration can be made inexpensively.
[0057]
In addition, when the internal combustion engine is started, the combustion gas of the combustion heater can be introduced into the catalyst, and the catalyst can be heated to promote activation. After the catalyst is heated, the combustion gas flows downstream of the catalyst. Can be exhausted, so that the catalyst is not heated more than necessary and the generation of sulfate can be prevented.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of an internal combustion engine having a supercharger according to the present invention. FIG. 2 is a diagram showing a relationship between a temperature of a gas containing a catalyst and a catalyst purification rate. FIG. 3 is a supercharger having a variable nozzle. FIG. 4 is a detailed view of a variable nozzle vane. FIG. 5 is a schematic sectional view of a combustion type heater. FIG. 6 is a view showing an exhaust switching valve control routine according to the embodiment.
DESCRIPTION OF SYMBOLS 1 ... Engine body 2 ... Intake device 3 ... Exhaust device 4 ... Heater core 5 ... Air cleaner 6 ... Turbocharger 6a ... Compressor 6b ... Turbocharger turbine 7 ... Intercooler 8 ... Intake manifold 9 ... Intake pipe 11 ... Intake throttle valve 12 ... Exhaust manifold 13 Exhaust purification catalyst 13a NOx catalyst 13b Oxidation catalyst 14 Exhaust pipe 15 Fuel addition nozzle 16 Fuel pump 17 Solenoid valve 18 ECU
19 temperature sensor (exhaust gas temperature detecting means)
20 EGR passage 21 EGR valve 22a Heater internal cooling water passage 22b Combustion cylinder 22c Partition wall 22d Combustion chamber 22e Air supply port 22f Exhaust outlet 24 Outer wall 25 Fuel introduction passage 31 Heater branch pipe 32 cooling water introduction passage 33 cooling water discharge passage 50 exhaust switching valve 51 combustion gas discharge pipe 61 turbine wheel 62 variable nozzle vane (variable nozzle)
63 ... drive ring 64 ... link 65 ... actuator 66 ... rods 67, 68 ... diaphragms 69, 70 ... diaphragm chambers 71, 72 ... spring 73 ... bellows 74, 75 ... inlet ports 76, 77 ... electric vacuum regulating valve 78 ... Vacuum pumps 80, 81 ... Atmospheric ports

Claims (3)

A combustion-type heater provided to raise the temperature of the engine-related elements by heat obtained by burning the fuel,
An EGR pipe that branches off from an exhaust pipe of the internal combustion engine and returns exhaust gas of the internal combustion engine to an intake pipe;
A supercharger that supercharges intake air by rotating a turbine provided in an exhaust pipe downstream of a branch point to the EGR pipe to rotate a compressor provided in an intake pipe;
An openable and closable variable nozzle that is provided in the turbine of the supercharger and increases the turbocharger pressure by increasing the rotation speed of the turbine when closed,
Combustion gas supply means for supplying combustion gas from the combustion heater to an exhaust pipe via the EGR pipe when the internal combustion engine is cranked;
A variable nozzle control unit that closes a variable nozzle of the turbine when supplying combustion gas with the combustion gas supply unit;
An internal combustion engine having a supercharger, comprising: A combustion-type heater provided to raise the temperature of the engine-related elements by heat obtained by burning the fuel,
An EGR pipe that branches off from an exhaust pipe of the internal combustion engine and returns exhaust gas of the internal combustion engine to an intake pipe;
A supercharger for supercharging intake air by rotating a turbine provided in an exhaust pipe downstream of a branch point to the EGR pipe to rotate a compressor provided in an intake pipe;
Combustion gas supply means for guiding combustion gas of the combustion heater to the turbine of the supercharger via the EGR pipe when the internal combustion engine is cranked;
A catalyst for purifying exhaust gas discharged from the internal combustion engine on the exhaust pipe,
A combustion gas exhaust pipe for introducing combustion gas from the combustion heater into an exhaust pipe located downstream of the catalyst;
A first route for guiding the combustion gas discharged from the combustion type heater to an exhaust pipe on the upstream side of the catalyst via an EGR pipe; An exhaust switching valve for selectively switching between a second route introduced to an exhaust pipe located downstream of the catalyst via a gas exhaust pipe;
An internal combustion engine having a supercharger, comprising: A catalyst for purifying exhaust gas discharged from the internal combustion engine is provided on the exhaust pipe, and a combustion gas exhaust pipe for introducing combustion gas from a combustion heater into an exhaust pipe located downstream of the catalyst is provided.
Further, a first route for guiding the combustion gas discharged from the combustion type heater to an exhaust pipe on the upstream side of the catalyst via an EGR pipe, and a combustion gas discharged from the combustion type heater via a combustion gas discharge pipe. 2. An internal combustion engine having a supercharger according to claim 1, further comprising an exhaust switching valve for selectively switching a second route introduced into an exhaust pipe located downstream of the catalyst.
that's all

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