JP2005090249A - Temperature control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control introducing exhaust gas to the proper temperature in an exhaust emission control device of an internal combustion engine. <P>SOLUTION: An ECU 1100 executes a program including a Step (S200) of supplying electric power to a glow plug 1400 when starting catalyst regenerating control (YES in S100), a Step (YES in S500, and S600) of turning off power supply of the electric power for a prescribed time, when determining that the catalyst regenerating control is not finished (NO in S300), and when power supply time of the glow plug 1400 is not within a continuous power supply possible time (NO in S400), and a Step (S800) of turning off the power supply of the electric power to the glow plug, when determining that the catalyst regenerating control is finished (YES in S300). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an exhaust purification device provided in an exhaust system of an internal combustion engine, and more particularly to a configuration of a temperature control device that controls the temperature of exhaust gas introduced into the exhaust purification device.

  In a diesel engine or a gasoline engine that performs lean combustion, an operation region in which an air-fuel mixture with a high air-fuel ratio (lean atmosphere) is used for combustion and the engine is operated occupies most of the entire operation region. In this type of engine (internal combustion engine), generally, an NOx absorbent (catalyst) that absorbs nitrogen oxides (NOx) in the presence of oxygen is provided in the exhaust system.

  Further, fine particles such as carbon discharged from a diesel engine are called PM (Particulate Matter), and many techniques have been developed for the removal thereof. For example, there is an exhaust particle processing apparatus in which an exhaust trap with a filter-like catalyst is interposed in an exhaust passage. This trap with catalyst self-combusts exhaust particulates deposited by the catalytic action. Techniques related to these are disclosed in the following publications.

  Japanese Patent Application Laid-Open No. 2002-285831 (Patent Document 1) discloses a method capable of at least partially regenerating the catalytic activity of a catalyst used for purification of diesel exhaust gas. This method for regenerating the catalytic activity of a catalyst in an exhaust gas line of a diesel engine is a catalyst having a catalytically active coating film having at least an oxidizing function on a honeycomb structure having no filter function provided in the exhaust gas line of a diesel engine. Is used. If the catalytic activity is reduced due to deposition of soot particles and hydrocarbons, the catalytic activity is regenerated. That is, combustion of soot particles and hydrocarbons deposited on the catalyst is initiated by limiting the exhaust gas temperature upstream of the catalyst to a temperature above 450 ° C. in time, and at least partially increasing the catalytic activity of the catalyst. To play.

  According to this method of regenerating the catalytic activity of the catalyst in the exhaust gas line of a diesel engine, regular regeneration of the catalytic activity avoids excessive deposition of combustible components and limits the exothermic reaction to a value that does not damage the catalyst. This contributes significantly to protect the catalyst against thermal damage. Therefore, the life of the catalyst can be increased.

  Japanese Patent Laid-Open No. 2001-355433 (Patent Document 2) estimates the amount of particulates deposited on the filter from the amount of desorbed smoke, and raises the exhaust gas temperature before the particulates accumulate in a deposited state on the filter. An exhaust purification device for an internal combustion engine that can avoid a situation in which fine particles are burned and the filter cannot be regenerated is disclosed. This exhaust purification device once collects particulates in the exhaust gas by a filter disposed in the engine exhaust passage in order to remove particulates contained in the exhaust gas, and oxidizes and removes the collected particulates. Try to regenerate. The filter is a filter that oxidizes and removes collected particulate matter in a state where no luminous flame occurs when the amount of particulate matter discharged by the internal combustion engine per unit time is smaller than the amount of particulate matter that can be removed by oxidation. is there. It is installed on the downstream side of the filter in the engine exhaust passage and has a particulate concentration sensor that detects the concentration of particulates contained in the exhaust gas at the installation location, and the output value of this particulate concentration sensor exceeds a specific set value Sometimes promotes oxidation removal of particulates on the filter.

According to the exhaust gas purification apparatus for an internal combustion engine, the amount of particulates deposited on the filter is estimated from the desorption smoke amount, and the particulate matter is burned by raising the exhaust gas temperature before the particulates are deposited in a layered manner on the filter. In addition, it is possible to avoid a situation where the filter cannot be regenerated.
JP 2002-285831 A JP 2001-355433 A

  In the method for regenerating the catalyst activity disclosed in Patent Document 1, the fuel is post-injected to generate a slow combustion position, the so-called post-burn phenomenon, and the temperature of the catalyst is raised to the activation temperature. Alternatively, the temperature of the catalyst is raised to the activation temperature with a burner installed upstream of the catalyst.

  However, there is a problem that the post-injection of fuel causes oil dilution to proceed simultaneously. In addition, in the burner, the durability and equipment of the exhaust system case due to a rapid temperature rise become complicated, and there is a problem of the burner fuel.

  In the exhaust gas purification apparatus for an internal combustion engine disclosed in Patent Document 2, the amount of PM deposited on the filter is estimated based on the concentration of PM in the exhaust gas. And before PM accumulates on a filter in laminated form, exhaust gas temperature is raised, oxidation removal is accelerated | stimulated, and the effect which avoids the filter unrecoverable situation is expressed by oxidizing PM. However, in this exhaust gas purification apparatus, it is essential to newly provide an electric heater in order to promote oxidation removal. Therefore, the apparatus becomes complicated, and there is a problem that the weight increases and the cost increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to reduce the exhaust gas introduced in the exhaust gas purification apparatus of an internal combustion engine with a simple structure without increasing new costs. It is to provide a temperature control device for controlling to an appropriate temperature.

  A temperature control device according to a first invention is a temperature control device in an exhaust purification mechanism of an internal combustion engine. The temperature control device is configured to determine whether or not the temperature increase of the exhaust gas from the internal combustion engine introduced into the exhaust gas purification mechanism is necessary. And a control means for controlling the internal combustion engine or an auxiliary machine of the internal combustion engine so as to increase the temperature of the exhaust gas.

  According to the first invention, in order to purify exhaust gas from a diesel engine, a catalyst for removing PM, which is particulates such as carbon, contained in the exhaust gas (for example, DPNR (Diesel Particulate NOx Reduction) catalyst) May be provided in the exhaust system. Then, PM collected in the catalyst may accumulate, and the filter included in the catalyst may be clogged. For this reason, so-called catalyst regeneration control is performed in which the temperature of the exhaust gas is raised to the activation temperature of the catalyst to oxidize and remove PM. During the catalyst regeneration control, the temperature of the exhaust gas introduced into the catalyst needs to be equal to or higher than a predetermined temperature (catalyst activation temperature) in order to prevent clogging of the front end of the catalyst. Therefore, by controlling an internal combustion engine (for example, a glow plug provided in a diesel engine) or an auxiliary machine (for example, an alternator) of the internal combustion engine at the time of catalyst regeneration control, the exhaust gas temperature is controlled to increase. Therefore, for example, by supplying power to the glow plug during catalyst regeneration control, the exhaust temperature can be raised by the heat generated by the glow plug itself. And since it controls to increase the electric power generation amount of an alternator with the electrical load of a glow plug, the load to an engine increases. As a result, the fuel supply amount is increased and the engine output is increased. Therefore, the temperature of the exhaust gas can be raised. Therefore, a burner or an electric heater is not required, and the exhaust temperature can be raised without incurring new costs with a simple structure.

  In the temperature control device according to the second invention, in addition to the configuration of the first invention, the internal combustion engine is a diesel engine. The control means includes means for controlling power to be supplied to a glow plug provided in the diesel engine.

  According to the second invention, in the diesel engine, the exhaust temperature can be raised by the heat generated by the glow plug itself by energizing the glow plug during the catalyst regeneration control. Furthermore, by supplying electric power to the glow plug, the supply of electric power from the alternator is also increased, and there is a synergistic effect that the engine load increases and the exhaust temperature increases.

  In the temperature control device according to the third invention, in addition to the configuration of the first invention, the control means includes means for controlling the output of the internal combustion engine to increase.

  According to the third invention, the exhaust gas temperature can be raised by raising the output of the internal combustion engine (for example, diesel engine) during the catalyst regeneration control.

  In the temperature control device according to the fourth aspect of the invention, in addition to the configuration of the third aspect of the invention, the internal combustion engine is a diesel engine. The control means is an auxiliary machine for the internal combustion engine, and is means for controlling power to be supplied to at least one of a light, an electric fan, and a glow plug supplied with electric power generated by the alternator. Further included.

  According to the fourth invention, in the diesel engine, at the time of catalyst regeneration control, power is supplied to at least one of a light, an electric fan, and a glow plug, which is an auxiliary device and is supplied with power generated by the alternator. As a result, the electrical load is increased. Therefore, the load on the engine is increased because the power generation amount of the alternator is controlled to increase. As a result, the amount of fuel supplied is increased and the engine output is increased. Therefore, the temperature of the exhaust gas can be raised.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  An embodiment in which a temperature control device in an exhaust gas purification apparatus for an internal combustion engine according to an embodiment of the present invention is applied to a diesel engine system will be described. First, a diesel engine system to which this temperature control device is applied will be described. This diesel engine system combines a high-pressure common rail fuel injection device, a large-capacity electronically controlled EGR (Exhaust Gas Recirculation) cooler, and a DPNR catalyst in order to realize clean exhaust of the diesel engine, and PM and NOx are continuously and simultaneously. It is a system to reduce.

  In FIG. 1, an internal combustion engine (hereinafter referred to as an engine) 1000 is an in-line four-cylinder diesel engine system including a fuel supply system 100, a combustion chamber 200, an intake system 300, an exhaust system 400, and the like as main parts.

  The fuel supply system 100 includes a supply pump 110, a common rail 120, a fuel injection valve 130, a shutoff valve 140, a metering valve 160, a fuel addition nozzle 170, an engine fuel passage 800 and an addition fuel passage 810, a glow plug 1400, and the like. Is done.

  The supply pump 110 pumps fuel from the fuel tank, raises the pumped fuel to a high pressure, and supplies the pumped fuel to the common rail 120 via the engine fuel passage 800. The common rail 120 functions as a pressure accumulation chamber that holds (accumulates) the high-pressure fuel supplied from the supply pump 110 at a predetermined pressure, and distributes the accumulated fuel to each fuel injection valve 130. The fuel injection valve 130 includes an electromagnetic solenoid therein, and is appropriately opened through a vortex chamber (not shown) to inject and supply fuel into the combustion chamber 200.

  A glow plug 1400 is installed in the vortex chamber, and the fuel injected into the vortex chamber can be preheated by the heat generating portion at the tip of the glow plug 1400. That is, when the engine is started, the startability is improved by preheating the combustion chamber by the heat generated by the glow plug 1400 in a state where the combustion chamber is cold and difficult to ignite.

  The supply pump 110 supplies a part of the fuel pumped from the fuel tank to the fuel addition nozzle (reducing agent injection nozzle) 170 via the added fuel passage 810. In the addition fuel passage 810, a shutoff valve 140 and a metering valve 160 are sequentially arranged from the supply pump 110 toward the fuel addition nozzle 170. The shutoff valve 140 shuts off the added fuel passage 810 in an emergency and stops the fuel supply. The metering valve 160 controls the pressure (fuel pressure) of the fuel supplied to the fuel addition nozzle 170. The fuel addition nozzle 170 is a mechanical on-off valve that opens when a fuel pressure (for example, 0.2 MPa) equal to or higher than a predetermined pressure is applied and injects fuel into the exhaust system 400 (exhaust port 410). That is, by controlling the fuel pressure upstream of the fuel addition nozzle 170 by the metering valve 160, desired fuel is injected and supplied (added) from the fuel addition nozzle 170 at an appropriate timing.

  The intake system 300 forms a passage (intake passage) for intake air supplied into each combustion chamber 200. The exhaust system 400 is configured by connecting various passage members such as an exhaust port 410, an exhaust manifold 420, a catalyst upstream side passage 430, and a catalyst downstream side passage 440 in order from upstream to downstream, and exhaust exhausted from each combustion chamber 200. A gas passage (exhaust passage) is formed.

  Further, the engine 1000 is provided with a known supercharger (turbocharger) 500. The turbocharger 500 includes two turbine wheels 520 and a turbine wheel 530 that are connected via a shaft 510. One turbine wheel (intake side turbine wheel) 530 is exposed to intake air in the intake system 300, and the other turbine wheel (exhaust side turbine wheel) 520 is exposed to exhaust in the exhaust system 400. The turbocharger 500 having such a configuration performs so-called supercharging in which the intake side turbine wheel 530 is rotated using the exhaust flow (exhaust pressure) received by the exhaust side turbine wheel 520 to increase the intake pressure.

  In the intake system 300, the intercooler 310 provided in the turbocharger 500 forcibly cools the intake air whose temperature has been increased by supercharging. The throttle valve 320 provided further downstream than the intercooler 310 is an electronically controlled on-off valve whose opening degree can be adjusted steplessly, and the flow area of the intake air is reduced under predetermined conditions. The function of adjusting (reducing) the supply amount of the intake air is provided.

  Further, the engine 1000 is formed with an exhaust gas recirculation passage (EGR passage) 600 that bypasses the upstream (intake system 300) and the downstream (exhaust system 400) of the combustion chamber 200. The EGR passage 600 has a function of returning a part of the exhaust to the intake system 300 as appropriate. The EGR passage 600 is opened and closed steplessly by electronic control, and an EGR valve 610 that can freely adjust the flow rate of exhaust gas flowing through the passage, and EGR for cooling the exhaust gas that passes (refluxs) through the EGR passage 600. A cooler 620 is provided.

  In the exhaust system 400, a DPNR catalyst 460 is provided downstream of the exhaust side turbine wheel 530 (between the catalyst upstream side passage 430 and the catalyst downstream side passage 440).

  The DPNR catalyst 460 is formed by combining a porous ceramic structure with a NOx storage reduction catalyst. The exhaust gas from the engine 100 is oxidized and reduced by the catalyst while passing through the gaps in the ceramics, and is then chemically changed into a harmless gas and discharged.

The NOx storage reduction catalyst absorbs NOx in a state where a large amount of oxygen is present in the exhaust gas, has a low oxygen concentration in the exhaust gas, and has a large amount of reducing component (for example, unburned component (HC) of fuel). In the existing state, NOx is reduced to NO ₂ or NO and released. NO NOx released as NO ₂ or NO, the N ₂ is further reduced due to quickly reacting with HC or CO in the exhaust. Incidentally, HC and CO are oxidized to H ₂ O and CO ₂ by reducing NO ₂ and NO.

  Further, in the DPNR catalyst 460, during the lean combustion (during lean combustion with a lot of oxygen), PM is temporarily collected by the porous structure catalyst, and at the same time, the active oxygen generated when storing NOx and It is oxidized and purified by oxygen in the exhaust gas. That is, NOx is temporarily stored in the catalyst during lean combustion, and thereafter reduced and purified by instantaneous rich combustion (concentrated air-fuel ratio combustion with less oxygen). Further, PM is oxidized and purified by active oxygen generated when the stored NOx is reduced during rich combustion. At this time, there is a possibility that the filter contained in the catalyst may be clogged due to accumulation of PM collected in the catalyst. Therefore, so-called catalyst regeneration control is performed in which the exhaust gas is raised to a predetermined temperature (catalyst activation temperature) or more, and the deposited PM is oxidized and removed.

  Various sensors are attached to each part of the engine 1000, and signals related to the environmental conditions of each part and the operating state of the engine 1000 are output.

  For example, the rail pressure sensor 700 outputs a detection signal corresponding to the fuel pressure stored in the common rail 120. The fuel pressure sensor 710 outputs a detection signal corresponding to the pressure (fuel pressure) Pg of the fuel introduced into the metering valve 160 among the fuel flowing through the added fuel passage 810. The air flow meter 720 outputs a detection signal corresponding to the flow rate (intake amount) Ga of intake air downstream of the throttle valve 320 in the intake system 300. The air-fuel ratio (A / F) sensor 730 outputs a detection signal that continuously changes in accordance with the oxygen concentration in the exhaust downstream of the catalyst casing of the exhaust system 400. Similarly, the exhaust temperature sensor 740 outputs a detection signal corresponding to the exhaust temperature (exhaust temperature) Tex at the downstream of the catalyst casing of the exhaust system 400.

  The accelerator opening sensor 750 is attached to the accelerator pedal of the engine 1000, and outputs a detection signal corresponding to the depression amount Acc of the pedal. The crank angle sensor 760 outputs a detection signal (pulse) every time the output shaft (crankshaft) of the engine 1000 rotates by a certain angle. Each of these sensors 700 to 760 is electrically connected to an electronic control unit (ECU) 1100.

  The ECU (Electronic Control Unit) 1100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a backup RAM, a timer, a counter, and the like, and these are also provided with A / D (Analog / Digital). ) An external input circuit including a converter and an external output circuit are connected by a bidirectional bus.

  The ECU 1100 configured as described above inputs detection signals from the various sensors via an external input circuit, and performs basic control for fuel injection and the like of the engine 1000 based on these signals, as well as a reducing agent (as a reducing agent). Various controls relating to the operating state of the engine 1000 are executed, such as control of addition of a reducing agent (fuel) relating to determination of addition timing and supply amount for the functioning fuel) addition.

  Alternator 900 is connected to the crankshaft via a belt. The alternator 900 generates power using the rotation of the crankshaft as a driving force. At this time, the generated electric power is supplied to various auxiliary machines (electric loads) of the electrically connected vehicle, or a part thereof is used to charge a battery (not shown). When the ECU 1100 detects that the electrical load increases, the ECU 1100 controls the power generation amount in the alternator 900 to increase. That is, ECU 1100 controls to increase the amount of fuel supplied so as to increase the output of the engine.

  Further, ECU 1100 performs at least a glow plug 1400 provided in the vortex chamber, a light 1200 installed in the front of the vehicle, and a cooling electric fan 1300 installed in the radiator at the time of engine start, operation from the driver and the inside of the radiator. On / off of power supply (energization) from the alternator 900 and the battery is controlled based on a predetermined condition such as the temperature of the battery.

  Next, an outline of the basic principle of fuel addition executed by the ECU 1100 will be described.

  In general, in a diesel engine, the oxygen concentration of a mixture of fuel and air used for combustion in a combustion chamber is in a high concentration state in most operating regions.

The oxygen concentration of the air-fuel mixture used for combustion is usually reflected directly in the oxygen concentration in the exhaust gas after subtracting the oxygen supplied for combustion. If the oxygen concentration (air-fuel ratio) in the air-fuel mixture is high The oxygen concentration (air-fuel ratio) in the exhaust gas basically increases similarly. On the other hand, as described above, the NOx storage reduction catalyst absorbs NOx when the oxygen concentration in the exhaust gas is high, and has a characteristic of reducing NOx to NO ₂ or NO and releasing it when the oxygen concentration is low. As long as the concentration is high, NOx is absorbed. However, when there is a limit amount in the NOx absorption amount of the catalyst and the catalyst absorbs the limit amount of NOx, NOx in the exhaust gas is not absorbed by the catalyst and passes through the catalyst casing.

Therefore, in an internal combustion engine such as the engine 1000 having the fuel addition nozzle 170, fuel is added to the upstream of the catalyst 450 of the exhaust system 400 through the fuel addition nozzle 170 at an appropriate time (hereinafter referred to as exhaust addition). Thus, the oxygen concentration in the exhaust gas is reduced and the amount of reducing component (HC, etc.) is increased. Then, the catalyst 450 reduces and releases the NOx absorbed so far to NO ₂ or NO, and recovers (regenerates) its own NOx absorption ability. As described above, the released NO ₂ and NO react with HC and CO to be quickly reduced to N ₂ . PM is oxidized and purified by active oxygen produced when the stored NOx is reduced.

  At this time, for the catalyst 450 that reduces and purifies the NOx absorbed by itself in the above-described manner, the reduction is performed by the amount of reducing component (fuel concentration) in the exhaust gas flowing into the catalyst casing and the oxygen concentration (air-fuel ratio). The efficiency of purification will be determined.

  Therefore, the engine 1000 performs fuel addition (fuel addition control) to the exhaust system 400 so that an appropriate amount of reducing component and air-fuel ratio in the exhaust gas can be stably obtained.

  In ECU 1100, the state in which PM is collected by DPNR catalyst 460 is detected by detecting the differential pressure across catalyst 450.

  In the catalyst 450, as shown in FIG. 2, the exhaust gas from the turbocharger 500 is introduced into the DPNR catalyst 460 into the catalyst 450. Here, when PM accumulated on the porous ceramic structure included in the DPNR catalyst 460 may clog the front end of the catalyst, the exhaust gas introduced into the catalyst 450 is raised to a predetermined temperature (catalyst activation temperature) or higher. The catalyst regeneration control is performed.

  The present invention is characterized in that, during catalyst regeneration control, the ECU 1100 increases the temperature of the catalyst inlet gas by controlling the glow plug 1400 to energize power. In other words, when the glow plug 1400 is energized, the glow plug 1400 itself generates heat, whereby the temperature of the exhaust gas can be raised. Further, by increasing the electrical load on the glow plug 1400, the ECU 1100 controls the power generation amount of the alternator 900 to increase. In other words, ECU 1100 controls to increase the engine output by increasing the fuel supply amount. As a result, the temperature of the exhaust gas can be raised.

  FIG. 3 shows a glow plug 1400 disposed in the fuel chamber of the diesel engine. The glow plug 1400 is provided in the vortex chamber 1440 in the compression chamber 1420 above the piston 1410. The glow plug 1400 is a start assist device that red heats the tip through an electric current immediately before starting the engine, sprays a part of the fuel spray from the injection nozzle 1430, preheats the fuel chamber, and promotes ignition and combustion. is there.

  With reference to FIG. 4, a control structure of a program executed by ECU 1100 which is the control apparatus according to the present embodiment will be described.

  In step (hereinafter abbreviated as S) 100, ECU 1100 determines whether or not catalyst regeneration control has been started. That is, for example, based on the differential pressure before and after the catalyst 460, it is determined whether there is a possibility that the filter is clogged. If it is determined that catalyst regeneration control is to be started (YES in S100), the process proceeds to S200. If not (NO in S100), the process waits until the catalyst regeneration control is started.

  In S200, ECU 1100 energizes glow plug 1400. In S300, ECU 1100 determines whether or not catalyst regeneration control has ended. When catalyst regeneration control ends (YES in S300), the process proceeds to S800. If not (NO in S300), the process proceeds to S400.

  In S400, ECU 1100 determines whether the energization time of glow plug 1400 is within the continuous energization possible time. Here, the “continuous energization possible time” is a time determined based on the specifications of the glow plug 1400 (for example, the lifetime, durability, etc. of the glow plug 1400). If ECU 100 determines that the energization time is within the energization time that allows continuous energization (YES in S400), the process proceeds to S200. If not (NO in S400), the process proceeds to S500.

  In S500, ECU 1100 turns off the energization of power to glow plug 1400. In S600, ECU 1100 determines whether or not a predetermined time has elapsed since the energization of power to glow plug 1400 was turned off. If it is determined that the predetermined time has elapsed (YES in S600), the process proceeds to S200. If not (NO in S600), the process proceeds to S700.

  In S700, ECU 1100 determines whether or not the catalyst regeneration control has ended. When catalyst regeneration control ends (YES in S700), this process ends. If not (NO in S700), the process proceeds to S600.

  In S800, ECU 1100 turns off the power supply to the glow plug.

  An operation of ECU 1100 that is the control device according to the present embodiment based on the above-described structure and flowchart will be described.

  When it is determined that the filter may be clogged during operation of the diesel engine and catalyst regeneration control is started (YES in S100), ECU 1100 energizes glow plug 1400 (S200). At this time, the exhaust temperature rises due to the heat generated by the glow plug 1400 itself. Further, the electrical load is increased by energizing the glow plug, the load of the alternator is increased, and the load of the engine 1000 is increased, so that the ECU 1100 controls the fuel supply amount to be increased. As a result, the exhaust temperature rises.

  If the continuous energization time set based on the durability of the glow plug or the like is exceeded by the end of catalyst regeneration control (NO in S300) (NO in S400), the ECU 1100 energizes the glow plug 1400. Is turned off (S500). When a predetermined time has elapsed (YES in S600), ECU 1100 energizes glow plug 1400 (S200). When ECU 1100 determines that the catalyst regeneration control has ended (YES in S300), it turns off the power supply to glow plug 1400 (S800).

  As described above, according to the temperature control device according to the present embodiment, during catalyst regeneration control, the glow plug is controlled to be energized intermittently without shortening the life of the glow plug, The temperature of the exhaust gas can be raised by the heat generated by the glow plug itself. Furthermore, the electric load is increased by the heat generated by the glow plug, and the power generation amount in the alternator is controlled to increase. That is, the temperature of the exhaust gas can be raised by controlling the fuel supply amount to be increased and the engine output to be increased. Therefore, clogging of the front end of the catalyst can be prevented at the time of catalyst regeneration control without requiring a burner and an electric heater that increase the cost.

  In the above-described embodiment, the case where the glow plug 1400 is energized has been described. However, the temperature control device according to the present invention is not limited to using the glow plug provided in the diesel engine in order to increase the electric load. . For example, during catalyst regeneration control, the power generation amount in the alternator may be controlled to increase by controlling various auxiliary devices that increase the electric load such as the light 1200 or the cooling electric fan 1300. That is, the temperature of exhaust gas can be raised by increasing the amount of fuel supplied and increasing the engine output. Alternatively, at least one of the glow plug 1400, the light 1200, and the cooling electric fan 1300 may be controlled to operate.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic structure figure showing a diesel engine system concerning an embodiment of the invention. It is a block diagram which shows the catalyst of FIG. A glow plug 1400 is shown disposed within a fuel chamber of a diesel engine. It is a flowchart which shows the control structure of the program performed by ECU of the diesel engine system which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Fuel supply system, 110 Supply pump, 120 Common rail, 130 Fuel injection valve, 140 Shutoff valve, 160 Metering valve, 170 Fuel addition nozzle, 200 Combustion chamber, 300 Intake system, 310 Intercooler, 320 Throttle valve, 400 Exhaust system , 410 exhaust port, 420 exhaust manifold, 430 catalyst upstream side passage, 440 catalyst downstream side passage, 450 catalyst, 460 DPNR catalyst, 500 turbocharger, 510 shaft, 520 exhaust side turbine wheel, 530 intake side turbine wheel, 600 EGR passage 610 EGR valve, 620 EGR cooler, 700 rail pressure sensor, 710 fuel pressure sensor, 720 air flow meter, 730 air-fuel ratio sensor, 740 exhaust temperature sensor, 750 accelerator opening sensor, 760 clan Angular sensor, 800 engine fuel path, 810 added fuel passage 900 alternator, 1000 engine, 1100 ECU, 1200 Light, 1300 electric cooling fan, 1400 glow plug 1410 piston, 1420 Con Passion chamber 1430 injection nozzle, 1440 swirl chamber.

Claims (4)

A temperature control device in an exhaust gas purification mechanism of an internal combustion engine,
Determining means for determining whether or not the temperature of the exhaust gas from the internal combustion engine introduced into the exhaust purification mechanism is necessary;
Control means for controlling the internal combustion engine or an accessory of the internal combustion engine to increase the temperature of the exhaust gas using electric power when the determination means determines that the temperature increase is necessary; Including a temperature control device. The internal combustion engine is a diesel engine,
The temperature control apparatus according to claim 1, wherein the control means includes means for controlling power to be supplied to a glow plug provided in the diesel engine.   The temperature control apparatus according to claim 1, wherein the control means includes means for controlling the output of the internal combustion engine to increase. The internal combustion engine is a diesel engine,
The control means is an auxiliary machine for the internal combustion engine, and is means for controlling power to be supplied to at least one of a light, an electric fan, and a glow plug supplied with power generated by an alternator. The temperature control device according to claim 3, further comprising:

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