JP2001193446A - Exhaust emission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To devise such a method that this exhaust emission control device operates a NOX-decomposing catalyst at the most suitable temperature of exhaust gas decomposes NOX, control the exhaust emission and also effectively recover exhaust gas energy. SOLUTION: This exhaust emission control device has a turbocharger 46 provided in an exhaust pipe 43, a NOX-decomposing device 30 provided with a NOX-decomposing catalyst provided in a backflow of the turbocharger 46, and a bypass pipe 45 branching from the upstream of the turbocharger 46 to bypass it to allow exhaust gas to flow. A controller 50 for controlling the opening of an opening/closing valve 48 provided in the exhaust pipe 43 according to the operating conditions of an engine 1, performs control allowing exhaust gas to flow in the bypass pipe 45 and/or the turbocharger 46.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is for purifying treating exhaust gas discharged from an engine, an exhaust gas purification device provided with a NO _X cracker on the downstream of the turbocharger incorporated in the exhaust pipe.

[0002]

2. Description of the Related Art Diesel engine combustion is based on heterogeneous mixing in which fuel is injected into high-temperature, high-pressure air. Unlike a homogeneous mixture, air and fuel are not uniformly mixed. The components change into soot, HC, and the like due to the high-temperature heat generated by combustion, and they aggregate to form particulates. Moreover, diesel engines, despite excellent fuel economy, NO _X in the exhaust gas, which contain toxic substances such as particulate matter, in order to remove these harmful substances from the exhaust gas, various These catalysts have been developed, but none of them are sufficient, and at present it is a problem in terms of environmental pollution.

[0003] In a diesel engine, acid is contained in exhaust gas.
NO _XTo reduce
When processing using zeolite or the like, NO_X
O inside_TwoO2 in the exhaust gas faster than_TwoReacts
And NO_XPhenomenon that it cannot be reduced
I do.

[0004] As an exhaust gas purification device for purifying exhaust gas discharged from an engine, in order to avoid the phenomenon as described above, degrade NO _X to a compound having a brownmillerite-like structure, in the exhaust gas catalyst (See, for example, JP-A-9-215921, JP-A-9-217618, and JP-A-9-25).
No. 3506).

[0005]

An exhaust gas purifying apparatus as described above comprises a compound having a brown-millarite-like structure,
The NO _x decomposition catalyst that synthesizes Rh and IrNO particles decomposes NO and NO ₂ by the action of electric charge, so
The O _X can be decomposed and removed. Such NO _X decomposition catalyst, decomposes very effectively NO _X, NO _X
The cracking catalyst, there is a proper temperature for the reaction temperature to reduce NO _X, for example, the optimum temperature for the reaction of compounds with brownmillerite-like structure is 300 ° C. to 450 degree ° C.. However, the temperature of the exhaust gas discharged from the engine is in a wide temperature range of about 150 ° C. to 650 ° C. For example, in a load region of a large diesel engine, it can be handled in an extremely narrow temperature range.

By the way, if the exhaust port, exhaust manifold, and exhaust pipe, which are the exhaust system of the engine, are made of ceramics such as Si ₃ N ₄ , and the wall is made up of a heat shielding structure in which a heat shielding air layer is formed, the exhaust gas emission is reduced. Temperature is 5 in partial load region
The temperature rises by about 0 ° C. to 70 ° C., and rises by about 100 ° C. in a high load region. However, at the exhaust gas temperature in the high load region, the NO _x
The cracking catalyst deteriorates, and it is necessary to reduce the temperature in a high load region. As a method of reducing the temperature of the exhaust gas discharged from the engine, cooling with water or air by a heat exchanger can be considered. However, the method of cooling the exhaust gas temperature by using a heat exchanger has the following problems. Energy is not effectively used.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and to convert heat energy of exhaust gas from an engine into motive power, thereby lowering the temperature of the exhaust gas. focuses in order to effectively utilize the thermal energy of the exhaust gas, the decomposition function of the NO _X decomposition catalyst is lowered until the exhaust gas temperature by operating the turbocharger at an appropriate temperature in the NO _X decomposition catalyst in a high load region effectively be exhibited, also, since the partial load range not to lower the exhaust gas temperature, exhaust gas is controlled to flow directly to the nO _X cracker to bypass the turbocharger, N
Disassembly function of O _X decomposition catalyst is to provide an exhaust gas purifying apparatus for controlling so as not to decrease.

According to the present invention, exhaust gas from an engine is exhausted.
To each exhaust port formed in the cylinder head
Exhaust manifold and exhaust manifold connected respectively
Turbocharger installed in the exhaust pipe connected to the
Provided in the exhaust pipe downstream of the turbocharger
NO_XNO with decomposition catalyst_XDisassembly device, the turboti
From the exhaust pipe upstream of the charger
Charger and NO _XTo the exhaust pipe between the decomposition device
Connected bypass pipe, and the exhaust gas is connected to the bypass pipe.
Or, adjust the flow rate of exhaust gas flowing to the turbocharger.
Opening / closing valve provided in the exhaust pipe and operation of the engine
A controller for controlling the opening of the on-off valve according to the state
An exhaust gas purifying apparatus comprising:

[0009] The controller, the exhaust gas from squeezing off valve in response to the exhaust gas temperature when the engine load is small is less than a predetermined temperature through said bypass pipe to said NO _X cracker At the same time, control is performed to reduce the work of the turbine of the turbocharger and reduce the intake air to the engine. In addition, the controller opens the on-off valve in response to the exhaust gas temperature being higher than a predetermined temperature when the engine load is large, and causes the exhaust gas to flow to the turbocharger so that the turbocharger operates at full load. The exhaust gas temperature is controlled to decrease by operating the exhaust gas.

The bypass passage is provided with an on-off valve for closing the bypass pipe when the load is high.

The NO _X decomposition catalyst of the NO _X decomposition apparatus comprises a compound having a brown-millerite-like structure and Rh or I
and r of the particle is synthesized NO _X decomposition products.

In this exhaust gas purifying apparatus, the exhaust port, the exhaust manifold, and the exhaust pipe cover the outer periphery of a pipe made of ceramics or heat-resistant metal with a heat-insulating air layer in order to prevent a decrease in the temperature of the exhaust gas. It is configured with a heat shield structure.

[0013] The turbocharger comprises a turbine driven by the exhaust gas, a compressor mounted on the turbine, and a generator provided on the shaft between the turbine and the compressor.

The exhaust manifold includes an exhaust passage portion connected to each of the exhaust ports, a gathering portion for gathering the exhaust passage portions, and an exhaust gas provided in the gathering portion from an outer peripheral portion to an inner peripheral portion. A cylindrical reactor that passes through and collects particulates contained in the exhaust gas at the outer peripheral portion; an exhaust collecting pipe connected to the inner peripheral portion of the collecting portion;
And a reactor provided in the cylindrical reactor and configured as a relief valve for communicating the outer peripheral portion to the inner peripheral portion in response to a pressure equal to or higher than a predetermined exhaust gas pressure. Therefore, particulate matter contained in exhaust gas is oxidized reaction by the reactor, changes in H ₂ O and CO _2, since no fed particulates materials to NO _X decomposition apparatus provided on the downstream of the exhaust pipe, It is not decreased function of the nO _X cracker.

[0015] The controller, the controls generated power of the generator provided in the turbocharger, and adjusted so that the exhaust gas outlet of the turbine to a temperature suitable for the NO _X decomposition catalyst, the generator The power generated by the machine is stored in a battery or controlled to be consumed for driving a motor connected to the engine.

Since the exhaust gas purifying apparatus is configured as described above, the opening degree of the on-off valve is controlled according to the engine load and the exhaust gas temperature. For example, the exhaust gas can be controlled to a temperature of about 350 ° C. to 450 ° C., and the exhaust gas in an appropriate temperature range can be sent to the NO _X decomposing device, and the NO _X reaction catalyst can be activated under the optimal temperature condition N
With O _X can be decomposed and at high load,
The exhaust gas energy of the exhaust gas can be effectively recovered by making full use of the operation of the turbocharger without cooling the exhaust gas with cooling water or the like, so that the fuel efficiency can be improved. At the load, the operating capacity of the compressor is reduced, the intake air is reduced, and the exhaust gas temperature is reduced. At this time, the exhaust gas flows by bypassing the turbocharger. As it passes through the manifold and exhaust pipe,
Since the temperature is maintained in the optimum temperature range for activating the NO _X reaction catalyst, the generation of NO _X can be suppressed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an exhaust gas purifying apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory view showing one embodiment of an exhaust gas purifying apparatus according to the present invention, FIG. 2 is a cross-sectional view showing one embodiment of a reactor provided in an exhaust manifold, and FIG. It is sectional drawing which shows a charger.

In the diesel engine 1 incorporating the exhaust gas purifying apparatus according to the present invention, the cylinder head 31 is fixed to the cylinder block 32 via the gasket 42, and the cylinder 41 is formed in a hole formed in the cylinder block 32. The fitted cylinder liner 33 is fitted. A reciprocating piston 34 is incorporated in the cylinder 41. The combustion chamber 40 is composed of a main chamber of a concave portion formed in the cylinder 41 and the piston 34 and / or a sub-chamber (not shown) formed in the cylinder head 31. The piston 34 is formed in a heat shielding structure having a heat shielding air layer using a material such as ceramics, for example. The cylinder head 31 is provided with an exhaust port 35 in which an exhaust valve 36 is arranged, an intake port (not shown) in which an intake valve is arranged, and a fuel supply means such as a fuel injection nozzle. . The exhaust port 35 is provided for the heat shielding air layer 3.
8, a ceramic port 37 is arranged,
It is configured as a heat shield structure. Also, the cylinder head 31
The exhaust manifold 2 is attached to the outlet of the exhaust port 35 via a mating base 39 and a manifold gasket (not shown).

[0019] The exhaust gas purifying apparatus, in particular, the turbocharger 46 provided in an exhaust pipe 43 connected to the exhaust manifold 2, the NO _X decomposition catalyst 53 provided in the exhaust pipe 44 of the flow after the turbocharger 46 NO _X cracker 30 comprises, upstream of the exhaust pipe 4 of the turbocharger 46
3 branched from the turbocharger 46 and the NO _X cracker 30 bypass pipe 45 connected to the exhaust pipe 44 between,
An on-off valve 49 provided in the exhaust pipe 43 for adjusting the flow rate of exhaust gas flowing exhaust gas to the bypass pipe 45 or the turbocharger 46, and an on-off valve 49 according to the operating state of the engine.
The controller 50 is configured to control the opening degree of the motor. Further, in this exhaust gas purifying apparatus, the bypass pipe 45 is provided with an on-off valve 48 for closing the bypass pipe 45 when the load is high.

The opening / closing valve 49 switches the exhaust gas passage 58 between a throttled state and an open state by operating the opening / closing valve actuator 51 in response to a command from the controller 50. When the exhaust gas passage 58 is narrowed by the on-off valve 49, the on-off valve 48 is switched to the full open state, and the exhaust gas passes through the bypass pipe 45 from the branch 47 at the inlet of the bypass pipe 45, and communicates with the connection part of the exhaust pipe 44. so fed directly to the NO _X cracker 30 from 52. In addition, on-off valve 4
9, when the exhaust gas passage 58 is opened, the on-off valve 48 is switched to the closing direction, and the exhaust gas does not pass through the bypass pipe 45 but flows through the turbine 54 of the turbocharger 46.
And the exhaust gas energy is collected by the compressor 55 and the generator 56.
4 to the NO _X decomposer 30 through the exhaust pipe 44. When the compressor 55 is operated,
Since a large amount of intake air supplied to the engine 1 is sent, it is possible to cope with a high load.

The controller 50, flow exhaust gas squeezing off valve 49 in response to the exhaust gas temperature when the engine load is small is less than a predetermined temperature through the bypass pipe 45 to the NO _X cracker 30 At the same time, control is performed to reduce the work of the turbine of the turbocharger 46 to reduce the intake air to the engine 1. The controller 50
In response to the fact that the exhaust gas temperature when the engine load is large is equal to or higher than a predetermined temperature, the on-off valve 49 is opened, the exhaust gas flows to the turbocharger 46, and the turbocharger 46 is operated at full load to operate the exhaust gas. Control to lower the temperature.

The NO _X decomposition catalyst 53 of the NO _X decomposition device 30 provided in the exhaust pipe 44 is, for example, a particle such as rhodium (Rh) or iridium (Ir) that decomposes NO _X contained in the exhaust gas or brown. A compound having a miralite-like structure (for example, see JP-A-9-215921 and JP-A-9-253506) is attached to a heat-resistant Ni-Cr-based alloy or ceramic fiber material and / or porous material. is configured, it can be efficiently degrade NO _X. NO of _X cracker 30 NO _X decomposition catalyst 53 is synthesized NO _X decomposition products and particles of the compound and Rh and Ir with brownmillerite-like structure.

In this exhaust gas purifying apparatus, the exhaust port 3
5. The exhaust manifold 2 and the exhaust pipe 43 cover the outer periphery of the passage pipe made of a heat-resistant material such as ceramics or heat-resistant metal in order to prevent the temperature of the exhaust gas from lowering.
It is configured as a heat shielding structure covered by 21 and 22. Also,
The turbocharger 46 is, for example, as shown in FIG.
It comprises a turbine 54 driven by exhaust gas, a compressor 55 attached to the turbine 54, and a generator 56 provided on a shaft 57 between the turbine 54 and the compressor 55. The load operation of the turbocharger 46 is to operate the compressor 55 to supply compressed air to the combustion chamber 40 of the engine 1 or to operate the generator 56 to generate power. The controller 50 controls the generated power of the generator 56 is adjusted so that the exhaust gas outlet of the turbine 54 to a temperature suitable for the NO _X decomposition catalyst 53, the electric power generated by the generator 56 to the battery 61 The power is stored or the motor 62 connected to the flywheel 60 attached to the output shaft of the engine 1 is driven to control the motor 62 to consume power to increase the output of the engine 1.

The exhaust manifold 2 includes, for example, a combustion chamber 4
HC, C, C contained in the exhaust gas discharged from 0
It can be configured to have a reactor 6 provided with a catalyst that collects O and particulate matter, reacts them, converts them to H ₂ O and CO ₂ , and decomposes NO _X. For example, as shown in FIG. 2, the exhaust manifold 2 includes an exhaust passage portion 3 connected to each exhaust port 35, a collecting portion 4 for collecting the exhaust passage portions 3, and an exhaust gas provided inside the collecting portion 4. 6 passes through the through-hole 23 through the inner peripheral passage 15 of the collecting portion 4 and the reactor 6 that allows the particulates contained in the exhaust gas to pass through the inner peripheral passage 15 from the outer peripheral passage 14 to the inner peripheral passage 15. And a relief valve 10 provided in a reactor 6 that connects the outer peripheral passage 14 to the inner peripheral passage 15 in response to a pressure higher than a predetermined exhaust gas pressure. .

The reactor 6 is placed horizontally in the collecting section 4 so as to intersect the flow direction of the exhaust gas, and the outer peripheral passage 14 and the inner peripheral passage 15 are
Are arranged so as to be formed. Further, the exhaust passage 3 of the exhaust manifold 2 is attached to the cylinder head 31 by a flange 19 provided at an end of the exhaust passage 3. The exhaust manifold 5 of the exhaust manifold 2 is attached to the exhaust pipe 43 by a flange 18 provided at an end of the exhaust manifold 5.

The exhaust passage 3, the collecting part 4 and the exhaust collecting pipe 5 in the exhaust manifold 2 are surrounded by casings 9, 7, 8 via heat shielding air layers 20, 21, 22 respectively. The exhaust passage portion 3, the collecting portion 4, and the exhaust collecting tube 5 are formed of heat-resistant ceramics such as silicon nitride or silicon carbide, and are supported by heat-insulating gaskets 13, 24 in casings 7, 8, 9 forming outer members. The heat shield air layers 20, 21 and 22 are formed between the two, and each is formed in a heat shield structure. The reactor 6 is supported by a support member 16 in the cylindrical collecting portion 4, and an inner peripheral passage 15 and an outer peripheral passage 14 are provided inside and outside the reactor 6.
Are formed.

The reactor 6 has one end formed as a closed end,
The other end is formed in the end opening 11. A valve seat 28 is provided in the end opening 11 of the reactor 6, and a valve guide 29 is formed in the cylindrical assembly 4 at a position corresponding to the end opening 11. End opening 11 of reactor 6
The relief valve 10 for opening and closing the valve is installed so as to be seated on the valve seat 28 while being guided by the valve guide 29. A spring retainer 17 is provided at the end of the relief valve 10.
The spring 12 is disposed between the valve guide 29 and the spring retainer 17. Accordingly, the relief valve 10 causes the particulate matter to accumulate on the outer peripheral surface 27 of the reactor 6 and causes clogging of the reactor 6, and the pressure of the exhaust gas existing in the outer peripheral passage 14 is reduced by the exhaust gas existing in the inner peripheral passage 15. When the pressure becomes larger than the predetermined pressure and reaches a predetermined pressure difference, the lift is lifted against the spring force of the spring 12 and the end opening 11 is opened. When the end opening 11 is opened, exhaust gas flows from the outer peripheral passage 14 through the end opening 11 to the inner peripheral passage 15 bypassing the reactor 6.

The exhaust gas flowing through the exhaust manifold 2 is
The gas flows from the exhaust passage 26 of the exhaust passage portion 3 into the outer peripheral passage 14 of the cylindrical collecting portion 4, at this time, flows in a tangential direction of the outer peripheral passage 14 of the reactor 6, flows into the outer periphery of the reactor 6 as a swirling flow, and then flows. , From the outer peripheral passage 14 of the reactor 6 to the inner peripheral passage 15. The exhaust gas is discharged from the inner peripheral passage 15 through the exhaust passage 25 of the exhaust manifold 5 to the downstream of the turbocharger or the like. Exhaust gas is exhaust manifold 2
, The particulate matter such as HC trapped on the outer peripheral surface 27 of the reactor 6 is heated and combusted on the outer peripheral surface 27 of the reactor 6 by the heat energy of the high-temperature exhaust gas, and H ₂ O, CO 2 _The response changes to ₂ .

The reactor 6 is made of a heat-resistant Ni-Cr-based alloy fiber material and / or porous material, or a heat-resistant ceramic fiber material and / or porous material. Further, a catalyst of Ni or Pt is attached to the fiber material or the porous material of the reactor 6 on or between the surfaces thereof. Although not shown, particulate matter such as HC and C trapped in the outer peripheral passage 14 of the reactor 6 is heated and burned by the heat energy of the exhaust gas, that is, reacts to change into H ₂ O and CO ₂ gas. The changed gas can be configured to join the exhaust gas passing through the reactor 6 to drive a turbocharger provided downstream.

In the exhaust manifold 2, when a certain amount of particulate matter accumulates in the reactor 6, the relief valve 10 opens the end opening 11 of the reactor 6, so that the exhaust gas flows from the outer peripheral passage 14 to the end opening 11. Through the inner peripheral passage 15 and then discharged from the exhaust manifold 5 to the exhaust pipe 43. At this time, the reactor 6
It will be reproduced as follows. In a heat-shielded diesel engine equipped with a turbocharger (not shown), the particulates are ignited at the high temperature of the exhaust gas itself and spontaneously ignited because the supercharging ratio is high and the O ₂ concentration in the exhaust gas is high. And heated and incinerated. In particular, in the case of a large heat shield engine having a high load factor, the temperature of the exhaust gas discharged from the combustion chamber 40 is set to a full load because the engine is frequently operated at a half load (1/2) or higher where the exhaust gas temperature is high. Then 8
Since the temperature rises to as high as 600 ° C. at 00 ° C. and partial load, and the particulates spontaneously ignite and burn, the chance of regenerating the reactor 6 increases, so the reactor 6 does not necessarily require a heater. However, depending on the engine, a heater such as a wire mesh capable of electrically heating the reactor 6 may be provided. In this case, the heater is energized and heated by a command from the controller according to the amount of particulates collected in the reactor 6. Of course, it may be controlled so as to reproduce the reactor 6. Reactor 6
The particulate matter trapped in the furnace is heated and incinerated by self-ignition, turned into a gas such as CO ₂ , H ₂ O, etc., discharged from the exhaust manifold 5, and sent to the turbocharger 46.

[0031]

As described above, in the exhaust gas purifying apparatus according to the present invention, since the on-off valve is switched according to the engine load and / or the exhaust gas temperature, the turbocharger is operated at full load when the load is high, and the exhaust gas energy is reduced. while being recovered, the exhaust gas temperature is promoted decomposition of the NO _X becomes proper temperatures for decomposition catalyst NO _X, without having to disable the ability of the NO _X decomposition catalyst, also at the time of partial load exhaust Gas bypasses turbocharger and NO
Since the exhaust gas is sent directly to the _X decomposition catalyst, the temperature of the exhaust gas does not become too low, and the temperature of the exhaust gas becomes an appropriate temperature for the NO _X decomposition catalyst, thereby promoting the decomposition of NO _X. Further, when the particulate substance contained in exhaust gas in the exhaust manifold preferably provided a reactor for the oxidation reaction, particulates materials are eliminated from the exhaust gas, without particulates substance is deposited in the NO _X decomposition catalyst, the function of the NO _X decomposition catalyst with sufficiently exhibited, thereby improving the durability.

Further, in this exhaust gas purifying device, a generator that generates electric power by operating a turbocharger driven by the exhaust gas energy of the engine can be used as an electric power supply means. However, the power supplied to the heater is the power generated by the exhaust gas energy using the generator provided in the turbocharger. There is no loss of engine power. Moreover, since the heater has an electric power that can always supply a current to the heater, the reactor is constantly heated, and no excessive particulates are deposited on the reactor, and the reactor is clogged. No high-temperature portions are generated locally, and the ceramics of the reactor do not burn out or break.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of an exhaust gas purifying apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing a reactor provided in an exhaust manifold.

FIG. 3 is a sectional view showing a turbocharger provided in an exhaust pipe.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Engine 2 Exhaust manifold 3 Exhaust passage part 4 Collecting part 5 Exhaust collecting pipe 6 Reactor 7, 8, 9 Casing 10 Release valve 14 Outer peripheral passage 15 Inner peripheral passage 20, 21, 22, 38 Heat shielding air layer 23 Through hole 25, 26 exhaust passage 27 outer peripheral surface 30 NO _X cracker 31 cylinder head 35 an exhaust port 37 ceramic port 40 combustion chamber 43, 44 exhaust pipe 45 a bypass pipe 46 turbocharger 47 branch portions 48 and 49 on-off valve 50 the controller 51 off valve actuator 52 communicating part 53 NO _X decomposition catalyst 54 turbine 55 compressor 56 generator 57 shaft 58 exhaust gas passage 61 battery 62 motor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 23/89 ZAB F01N 3/02 321J F01N 3/02 321 3/10 A 3/10 3/28 301C 3 / 28 301 F02B 37/00 302B F02B 37/00 302 37/12 302D 37/18 302E 37/12 302 B01D 53/36 102B F02B 37/12 301E F-term (reference) 3G005 DA02 EA04 EA16 GA02 GB24 GB27 GD13 GD14 HA15 HA18 HA19 3G090 AA03 BA01 BA04 EA05 3G091 AA10 AA14 AA18 AA28 AB05 AB12 BA00 BA04 BA14 BA15 BA19 BA39 CA05 CA13 CB07 CB08 DA01 DA02 DA05 DB10 EA17 EA32 FA12 FA13 FA14 FB02 FB03 FB10 GA04 GA05 GB01 GB03 GB01 GB01 AGB03 BA09X BA33X CA01 CD08 DA01 4G069 AA02 AA04 BA16A BA16B BC71A BC71B BC74A BC74B CA03 CA10 CA13

Claims (9)

[Claims] An exhaust manifold connected to each exhaust port formed in a cylinder head for discharging exhaust gas from an engine; a turbocharger provided in an exhaust pipe connected to the exhaust manifold; the exhaust pipe NO _X decomposition apparatus comprising a NO _X decomposition catalyst provided in the downstream, the between branches from the exhaust pipe upstream of the turbocharger and the turbocharger and the NO _X cracker A bypass pipe connected to an exhaust pipe, an on-off valve provided on the exhaust pipe for adjusting an exhaust gas flow rate for flowing the exhaust gas to the bypass pipe or the turbocharger, and an on-off valve for the on-off valve according to an operating state of an engine. An exhaust gas purification device consisting of a controller that controls the opening. Wherein said controller, said the exhaust gas concentrates the on-off valve in response to the exhaust gas temperature when the engine load is small is less than a predetermined temperature through said bypass pipe NO _X decomposition 2. The exhaust gas purifying apparatus according to claim 1, further comprising controlling the flow of the exhaust gas to the apparatus and reducing the work of a turbine of the turbocharger to reduce the intake air to the engine. 3. The controller according to claim 1, wherein the controller opens the on-off valve in response to the exhaust gas temperature being higher than a predetermined temperature when the engine load is large, and flows the exhaust gas to the turbocharger. 2. The exhaust gas purifying apparatus according to claim 1, wherein the exhaust gas purifying apparatus is controlled to lower the exhaust gas temperature by operating the exhaust gas at full load. 4. The exhaust gas purifying apparatus according to claim 1, wherein the bypass pipe is provided with an on-off valve for closing the bypass pipe at a high load. Wherein said NO _X catalyst for decomposing the NO _X decomposition apparatus, according to claim 1 which consists of particles of compound and Rh and Ir with brownmillerite-like structure which is synthesized NO _X decomposition products Exhaust gas purification equipment. 6. A heat shielding structure in which the exhaust port, the exhaust manifold, and the exhaust pipe cover the outer periphery of a passage pipe made of ceramics or heat-resistant metal with a heat shielding air layer in order to prevent a temperature decrease of the exhaust gas. The exhaust gas purifying apparatus according to claim 1, wherein the exhaust gas purifying apparatus is configured as follows. 7. The turbocharger includes a turbine driven by the exhaust gas, a compressor mounted on the turbine, and a generator provided on the shaft between the turbine and the compressor. The exhaust gas purifying apparatus according to claim 1, comprising: Wherein said controller controls the generated power of the generator provided in the turbocharger, and adjusted so that the exhaust gas outlet of the turbine to a temperature suitable for the NO _X decomposition catalyst, The exhaust gas purifying apparatus according to claim 7, further comprising: controlling the power generated by the generator to be stored in a battery or consumed for driving a motor connected to the engine. 9. An exhaust manifold connected to each of the exhaust ports, an aggregate for gathering the exhaust passages, and an exhaust gas provided inside the aggregate for transferring an exhaust gas from an outer peripheral portion to an inner peripheral portion. A reactor that passes through the section and collects particulates contained in the exhaust gas at the outer peripheral section, an exhaust collecting pipe connected to the inner peripheral section of the collecting section,
2. An exhaust gas purifying apparatus according to claim 1, further comprising a relief valve provided in said reactor for communicating said outer peripheral portion with said inner peripheral portion in response to a pressure higher than a predetermined exhaust gas pressure. .