WO2015141756A1 - Internal combustion engine - Google Patents

Internal combustion engine Download PDF

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Publication number
WO2015141756A1
WO2015141756A1 PCT/JP2015/058153 JP2015058153W WO2015141756A1 WO 2015141756 A1 WO2015141756 A1 WO 2015141756A1 JP 2015058153 W JP2015058153 W JP 2015058153W WO 2015141756 A1 WO2015141756 A1 WO 2015141756A1
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WO
WIPO (PCT)
Prior art keywords
channel
egr
valve
exhaust
egr valve
Prior art date
Application number
PCT/JP2015/058153
Other languages
French (fr)
Inventor
Shu Kobayashi
Original Assignee
Toyota Jidosha Kabushiki Kaisha
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Publication date
Application filed by Toyota Jidosha Kabushiki Kaisha filed Critical Toyota Jidosha Kabushiki Kaisha
Publication of WO2015141756A1 publication Critical patent/WO2015141756A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/42—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories having two or more EGR passages; EGR systems specially adapted for engines having two or more cylinders
    • F02M26/44—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories having two or more EGR passages; EGR systems specially adapted for engines having two or more cylinders in which a main EGR passage is branched into multiple passages
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/17—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the intake system
    • F02M26/21—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the intake system with EGR valves located at or near the connection to the intake system
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/22—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with coolers in the recirculation passage
    • F02M26/33—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with coolers in the recirculation passage controlling the temperature of the recirculated gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/50—Arrangements or methods for preventing or reducing deposits, corrosion or wear caused by impurities
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/02—EGR systems specially adapted for supercharged engines
    • F02M26/04—EGR systems specially adapted for supercharged engines with a single turbocharger
    • F02M26/06—Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/02—EGR systems specially adapted for supercharged engines
    • F02M26/09—Constructional details, e.g. structural combinations of EGR systems and supercharger systems; Arrangement of the EGR and supercharger systems with respect to the engine
    • F02M26/10—Constructional details, e.g. structural combinations of EGR systems and supercharger systems; Arrangement of the EGR and supercharger systems with respect to the engine having means to increase the pressure difference between the exhaust and intake system, e.g. venturis, variable geometry turbines, check valves using pressure pulsations or throttles in the air intake or exhaust system
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/14—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system
    • F02M26/15—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system in relation to engine exhaust purifying apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
    • F02M26/35—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with means for cleaning or treating the recirculated gases, e.g. catalysts, condensate traps, particle filters or heaters
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/65—Constructional details of EGR valves
    • F02M26/72—Housings
    • F02M26/73—Housings with means for heating or cooling the EGR valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/65—Constructional details of EGR valves
    • F02M26/74—Protection from damage, e.g. shielding means

Definitions

  • the present invention relates to an internal combustion engine, and in particular, an internal combustion engine to which an EGR gas can be introduced.
  • the patent literature 1 discloses a conventional internal combustion engine provided with a turbocharger.
  • the internal combustion engine includes an intercooler that cools supercharged intake air and an EGR cooler that cools EGR gas introduced into an intake channel upstream of a compressor.
  • the amount of EGR gas is controlled to prevent water condensation in the intercooler and the EGR cooler.
  • Patent Literature 1 Japanese Patent Laid-Open No. 2012-087779
  • the EGR valve is opened to introduce the EGR gas without any consideration on the occurrence of water condensation on the EGR valve described above, the condensate water flows into the intake channel. However, if introduction of the EGR gas is inhibited until the internal combustion engine is completely warmed up and the condensate water on the EGR valve disappears, the effect of the EGR gas introduction on improvement of the fuel consumption cannot be achieved.
  • the present invention has been devised to solve the problems described above, and an object of the present invention is to provide an internal combustion engine that can quickly heat an EGR valve and start introducing EGR gas early in the state where there is no condensate water on the EGR valve and its periphery.
  • an internal combustion engine includes a compressor that supercharges intake air, an EGR channel, an EGR valve, a communicating channel, and an open-close valve.
  • the EGR channel connects an intake channel upstream of the compressor and an exhaust channel to each other.
  • the EGR valve is disposed at an end of the EGR channel closer to the intake channel or at a midpoint in the EGR channel and adjusts the flow rate of EGR gas flowing in the EGR channel.
  • the communicating channel connects the EGR channel and the exhaust channel to each other.
  • the open-close valve opens and closes the communicating channel.
  • the communicating channel is connected to the EGR channel at a point immediately upstream of the EGR valve along a direction of a flow of the EGR gas and to the exhaust channel at a point where there is a pressure difference with respect to the pressure in the exhaust channel at a connection point between the EGR channel and the exhaust channel or where the pressure difference is caused by an operation of a predetermined actuator.
  • the internal combustion engine further includes controlling means for opening the open-close valve in a case where water condensation occurs on the EGR valve or there is a possibility that water condensation occurs on the EGR valve in the state where the EGR valve is closed.
  • At least one device that lowers the pressure in the exhaust channel is disposed in the exhaust channel at a point between the connection point between the EGR channel and the exhaust channel and the connection point between the communicating channel and the exhaust channel.
  • a throttle valve that narrows the exhaust channel when the open-close valve is opened is disposed in the exhaust channel as the predetermined actuator at a point between the connection point between the EGR channel and the exhaust channel and the connection point between the communicating channel and the exhaust channel.
  • the internal combustion engine further includes an EGR cooler.
  • the EGR cooler is disposed in the EGR channel upstream of the EGR valve along the flow of the EGR gas and cools the EGR gas flowing in the EGR channel.
  • the connection point between the communicating channel and the exhaust channel is located upstream of the connection point between the EGR channel and the exhaust channel along the flow of the exhaust gas in the exhaust channel.
  • the open-close valve if the open-close valve is opened in the cold state during which the EGR valve is closed, part of the exhaust gas flowing in the exhaust channel can flow through the EGR channel and the communicating channel while being in contact with the EGR valve.
  • the EGR valve can be heated by the heat of the exhaust gas. In this way, occurrence of water condensation on the EGR valve can be prevented, or any condensate water can be removed (evaporated).
  • an internal combustion engine capable of quickly heating the EGR valve and starting introduction of EGR gas early in the state where there is no condensate water on the EGR valve and its periphery.
  • the EGR valve in the case where water condensation has occurred, or can occur, on the EGR valve, the EGR valve can be heated by the heat of the exhaust gas introduced through the EGR channel and the communicating channel. In this way, occurrence of water condensation on the EGR valve can be prevented, or any condensate water can be removed (evaporated).
  • the device that lowers the pressure in the exhaust channel can be used to produce a flow of exhaust gas that flows in contact with the EGR valve when the open-close valve is opened in the state where the EGR valve is closed.
  • the throttle valve that narrows the exhaust channel when the open-close valve is opened can be used to produce a flow of exhaust gas that flows in contact with the EGR valve when the open-close valve is opened in the state where the EGR valve is closed.
  • a flow channel configuration can be formed in which the exhaust gas flows from the exhaust channel into the communicating channel and then into the EGR channel when the open-close valve is opened.
  • Figure 2 is a diagram showing a characteristic configuration of an LPL EGR device and its periphery shown in Figure 1.
  • Figure 3 is a flow chart showing a routine performed in the embodiment 1 of the present invention.
  • Figure 4 is a diagram for illustrating a method of estimating the temperature of an EGR valve.
  • Figure 5 is a diagram showing the effect of the operation of heating the EGR valve.
  • Figure 6 is a diagram showing another example of connection points of an EGR channel and a communicating channel to an exhaust channel.
  • Figure 7 is a diagram showing a characteristic configuration of the EGR device and its periphery according to an embodiment 2 of the present invention.
  • Figure 8 is a flow chart showing a routine performed in the embodiment 2 of the present invention.
  • Figure 9 is a diagram showing a characteristic configuration of the EGR device and its periphery according to an embodiment 3 of the present invention.
  • Figure 10 is a flow chart showing a routine performed in an embodiment 3 of the present invention.
  • Figure 11 is a diagram showing a modification of the configuration of the EGR device and its periphery according to the embodiment 3 of the present invention.
  • An air cleaner 16 is attached to the intake channel 12 at a point in the vicinity of an inlet thereof.
  • An air flowmeter 18 that outputs a signal responsive to the flow rate of air sucked into the intake channel 12 and an intake air temperature sensor 20 that detects the temperature of the intake air are provided at a point downstream of, and in the vicinity of, the air cleaner 16.
  • a compressor 22a of a turbocharger 22 is installed downstream of the air flowmeter 18.
  • the compressor 22a is connected to and integrated with a turbine 22b disposed in the exhaust channel 14 by a connecting shaft.
  • An intercooler 24 that cools air compressed by the compressor 22a is provided downstream of the compressor 22a.
  • An electronically controlled throttle valve 26 is provided downstream of the intercooler 24.
  • the exhaust channel 14 is provided with various kinds of catalysts for purifying exhaust gas at a point downstream of the turbine 22b.
  • the exhaust channel 14 is provided with an upstream-side catalyst (S/C) 28 and a downstream-side catalyst (U/F) 30, which are both three way catalysts, the upstream-side catalyst 28 being located upstream of the downstream-side catalyst 30 along the flow of the exhaust gas.
  • S/C upstream-side catalyst
  • U/F downstream-side catalyst
  • the internal combustion engine 10 shown in Figure 1 is provided with a low pressure loop (LPL) EGR device 32.
  • the EGR device 32 includes an EGR channel 34 that connects the exhaust channel 14 downstream of the turbine 22b and the intake channel 12 upstream of the compressor 22a to each other.
  • the EGR channel 34 is provided with an EGR cooler 36 and an EGR valve 38, the EGR cooler 36 being located upstream of the EGR valve 38 along the flow of the EGR gas introduced into the intake channel 12.
  • the EGR cooler 36 is a water-cooling cooler provided for cooling the EGR gas flowing in the EGR channel 34.
  • the EGR valve 38 is provided for adjusting the amount of EGR gas to be recirculated to the intake channel 12 through the EGR channel 34.
  • a valve body 38a (see Figure 2) of the EGR valve 38 is heated by engine cooling water.
  • the temperature of the engine cooling water supplied to the EGR cooler 36 is controlled to be higher than the dew point of the exhaust gas (EGR gas) passing through the EGR cooler 36.
  • the system according to this embodiment is characterized by the configuration of the EGR device 32 and its periphery.
  • the characteristic configuration will be described in detail with reference to Figure 2.
  • the system shown in Figure 1 includes an electronic control unit (ECU) 40.
  • ECU electronice control unit
  • sensors that detect the operational state of the internal combustion engine 10, such as the air flowmeter 18 and the intake air temperature sensor 20 described above, a crank angle sensor 42 that detects the engine speed, and a water temperature sensor 44 that detects the temperature of engine cooling water, are connected to an input part of the ECU 40.
  • FIG 2 is a diagram showing a characteristics configuration of the LPL EGR device 32 and its periphery shown in Figure 1.
  • end of the EGR channel 34 closer to the exhaust channel 14 is connected to the exhaust channel 14 at a point between the upstream-side catalyst 28 and the downstream-side catalyst 30.
  • the EGR valve 38 is disposed at an end of the EGR channel 34 closer to the intake channel 12 in this example, the EGR valve 38 according to the present invention may be disposed at a midpoint on the EGR channel 34.
  • the EGR valve 38 In the early stage of warming up after starting from the cold state, the EGR valve 38 is typically closed in order to ensure good combustion and because water condensation tends to occur. Although the EGR valve 38 is closed, however, the EGR channel 34 upstream of the EGR valve 38 (on the side closer to the exhaust channel 14) along the flow of the EGR gas is filled with exhaust gas as a result of exhaust pulsation, and gas exchange constantly occurs there. Therefore, moisture in the exhaust gas can condense on the cold EGR valve 38. Thus, in the cold state during which the EGR valve 38 is closed, water condensation can occur on the surface of the EGR valve 38 on the side of the exhaust channel 14 and its vicinity.
  • the EGR valve 38 is opened to introduce the EGR gas without any consideration on the occurrence of water condensation on the EGR valve 38 described above, the condensate water flows into the intake channel 12. As a result, there is a possibility that a component of an intake system corrodes. In the case where the EGR gas is introduced to the intake channel 12 upstream of the compressor 22a as with the internal combustion engine 10 according to this embodiment, not only the corrosion of the compressor 22a but also wear (erosion) of the compressor 22a because of collision of the condensate water can occur.
  • a communicating channel 50 and an open-close valve 52 shown in Figure 2 are provided.
  • the communicating channel 50 connects the EGR channel 34 immediately upstream of the EGR valve 38 along the direction of the flow of the EGR gas and the exhaust channel 14 downstream of the downstream-side catalyst 30.
  • the open-close valve 52 is disposed on the communicating channel 50 to open and close the communicating channel 50.
  • the open-close valve 52 is electrically connected to the ECU 40 described above.
  • the downstream-side catalyst 30 is disposed between a connection point 50a between the communicating channel 50 and the exhaust channel 14 and a connection point 34a between the EGR channel 34 and the exhaust channel 14. Therefore, it can be said that the communicating channel 50 is connected to the exhaust channel 14 at a point (the connection point 50a) at which there is a pressure difference with respect to the pressure in the exhaust channel at the connection point 34a to the EGR channel 34 because of the pressure loss by the downstream-side catalyst 30.
  • the downstream-side catalyst 30 as a device for lowering the pressure in the exhaust channel is disposed between the connection point 34a to the EGR channel 34 and the connection point 50a to the communicating channel 50.
  • the open-close valve 52 is opened in the cold state during which the EGR valve 38 is closed, part of the exhaust gas flowing through the exhaust channel 14 forms an exhaust gas flow that is fed back to the exhaust channel 14 downstream of the downstream-side catalyst 30 by passing through the EGR channel 34 and then the communicating channel 50.
  • the connection point between the communicating channel 50 and the EGR channel 34 is immediately upstream of the EGR valve 38 along the direction of the flow of the EGR gas (when the EGR gas is introduced). Therefore, when the exhaust gas flows from the EGR channel 34 to the communicating channel 50, the exhaust gas flows while being in contact with the EGR valve 38. As a result, the EGR valve 38 can be heated by the heat of the exhaust gas.
  • the EGR valve 38 can be quickly heated compared with the case of using the heat of the exhaust gas that intermittently reaches the EGR valve 38 as a result of exhaust pulsation. As a result, occurrence of water condensation can be prevented, or any condensate water can be removed (evaporated).
  • the cold EGR valve 38 can be quickly heated by opening the open-close valve 52 in the state where the EGR valve 38 is closed.
  • a control to open the open-close valve 52 is performed in the case where water condensation has occurred or can occur on the EGR valve 38 in the state where the EGR valve is closed. More specifically, the temperature of the EGR valve 38 is estimated, and in the case where the estimated temperature of the EGR valve 38 is equal to or lower than a predetermined valve XI , a control to open the open-close valve 52 (an operation of heating the EGR valve) is performed on the condition that the engine cooling water temperature THW satisfies a predetermined condition.
  • Figure 3 is a flow chart showing a control routine performed by the ECU 40 to achieve the characteristic control according to the embodiment 1 of the present invention.
  • This routine is activated when the internal combustion engine is started from the cold state and repeatedly performed at a predetermined control cycle.
  • the EGR valve 38 is closed when the internal combustion engine is started from the cold state.
  • the ECU 40 calculates the estimated temperature of the EGR valve.
  • the estimated temperature of the EGR valve is calculated as a function of the intake air temperature THA, the engine cooling water temperature THW and time, for example.
  • Figure 4 is a diagram for illustrating a method of estimating the temperature of the EGR valve 38.
  • the ECU 40 stores a map that determines a base value Teo of the temperature of the EGR valve 38 from a relationship between the intake air temperature THA and the engine cooling water temperature THW as shown in Figure 4.
  • the base value Teo referred to herein means a steady temperature of the EGR valve 38 in the case where the intake air temperature THA and the engine cooling water temperature THW are arbitrary values.
  • the value Teo for the intake air temperature THA detected by the intake air temperature sensor 20 and the engine cooling water temperature THW detected by the water temperature sensor 44 is determined by referring to the map shown in Figure 4. Then, based on the value Teo, a current temperature Tn of the EGR valve 38, which varies with the intake air temperature THA and the engine cooling water temperature THW with a temporal delay, is calculated according to the formula (1).
  • T n- i denotes the previous value of the temperature of the EGR valve 38
  • k denotes a preset smoothing coefficient (0 ⁇ k ⁇ 1). It is assumed that the water temperature sensor 44 measures, as the engine cooling water temperature THW, the temperature of the valve body 38a at a point where the temperature is correlated with the engine cooling water temperature.
  • T n T n -i + (Teo - T n .,) k ... (1)
  • step 102 in which it is determined whether or not the estimated temperature Tn of the EGR valve is equal to or lower than the predetermined valve XI .
  • the predetermined valve XI is a temperature at which condensation starts occurring on the EGR valve 38 (that is, the dew point of the exhaust gas in the vicinity of the EGR valve 38).
  • the processing of this step 102 is to determine whether or not water condensation has occurred or can occur on the EGR valve 38.
  • step 102 If the result of the determination in step 102 is negative, the ECU 40 proceeds to step 104, and the open-close valve 52 is closed or the state where the open-close valve 52 is closed is maintained. That is, in this case, the operation of heating the EGR valve is not performed.
  • step 106 it is determined whether or not the engine cooling water temperature THW is higher than a predetermined valve X2.
  • the water temperature sensor 44 measures, as the engine cooling water temperature THW, a temperature at a point where the measured temperature is correlated with the engine cooling water temperature on the EGR cooler 36.
  • the predetermined valve X2 corresponds to the value of the engine cooling water temperature THW detected by the water temperature sensor 44 when the engine cooling water temperature on the EGR cooler 36 is equal to the dew point of the exhaust gas in the vicinity of the EGR cooler 36.
  • step 106 If the result of the determination in step 106 is negative, the ECU 40 proceeds to step 104, and the operation of heating the EGR valve is not performed. On the other hand, if the result of the determination in step 106 is positive, the ECU 40 proceeds to step 108, and the operation of heating the EGR valve is performed (that is, the open-close valve 52 is opened, or the state where the open-close valve 52 is opened is maintained).
  • the operation of heating the EGR valve is performed on the condition that the result of the determination in step 106 is positive.
  • the EGR valve 38 can be quickly heated, and introduction of the EGR gas can be started early in the state where there is no condensate water on the EGR valve 38 and its periphery.
  • the operation of heating the EGR valve is permitted on the condition that the engine cooling water temperature is higher than the predetermined valve X2 and therefore it is determined that the engine cooling water temperature on the EGR cooler 36 is higher than the dew point of the EGR gas.
  • the exhaust gas can be introduced to the EGR valve 38 and its periphery to heat the EGR valve 38 while ensuring that water condensation does not occur when the exhaust gas passes through the EGR cooler 36.
  • the operation of heating the EGR valve according to the present invention may be performed when the condition concerning the engine cooling water temperature is not satisfied.
  • FIG. 5 is a diagram showing the effect of the operation of heating the EGR valve.
  • the temperature of the EGR valve 38 (the temperature of the surface of the head upstream along the flow of the EGR gas) in the case where the internal combustion engine is started from the cold state quickly increases compared with the case where the control is not performed. It can also be seen that this control shortens the time required for the temperature of the EGR valve 38 to reach the dew point of the EGR gas. In this way, this control can improve the heating of the EGR valve 38.
  • the EGR channel 34 and the communicating channel 50 are arranged so that the downstream-side catalyst 30 is disposed in the exhaust channel 14 between the connection point 34a to the EGR channel 34 and the connection point 50a to the communicating channel 50.
  • the arrangement that uses the pressure loss in the downstream-side catalyst 30 or other device in order to ensure an adequate flow rate of the exhaust gas in the operation of heating the EGR valve is not limited to that described above, and the arrangement shown in Figure 6 described below is also possible, for example.
  • FIG 6 is a diagram showing another example of the connection points of the EGR channel and the communicating channel to the exhaust channel.
  • An EGR device 60 shown in Figure 6 differs from the EGR device 32 shown in Figure 2 in that an EGR channel 62 is connected to the exhaust channel 14 upstream of the turbine 22b.
  • the configuration shown in Figure 6 differs from the configuration shown in Figure 2 in that a communicating channel 64 is connected to the exhaust channel 14 downstream of the turbine 22b (and upstream of the upstream-side catalyst 28).
  • the EGR channel 62 and the communicating channel 64 are arranged so that the turbine 22b is disposed in the exhaust channel 14 between a connection point 62a to the EGR channel 62 and a connection point 64a to the communicating channel 64. That is, in this example, the pressure loss in the turbine 22b is used for the operation of heating the EGR valve.
  • the EGR device to which the present invention is applied is not limited to the LPL EGR device, such as the EGR device 32 described above, and the present invention can also be applied to a high pressure loop (HPL) EGR device.
  • HPL high pressure loop
  • connection point 64a to the communicating channel 64 is a point in the exhaust channel 14 upstream of the upstream-side catalyst 28 in this example
  • the connection point 64a to the communicating channel 64 may be a point between the upstream-side catalyst 28 and the downstream-side catalyst 30 or a point downstream of the downstream-side catalyst 30.
  • Such a device may be a device other than the three way catalyst or turbine as far as it can lower the pressure in the exhaust channel and appropriately produce a pressure difference between the connection points 62a and 64a.
  • the device may be an exhaust gas purifying catalyst other than the three way catalyst or a particulate filter that collects a particulate matter contained in the exhaust gas.
  • controlling means according to the second aspect of the present invention described earlier is provided by the ECU 40 performing a series of processings of the routine shown in Figure 3.
  • FIG. 7 is a diagram showing a characteristic configuration of the EGR device 32 and its periphery according to the embodiment 2 of the present invention.
  • the configuration shown in Figure 7 differs from the configuration shown in Figure 2 in that a communicating channel 70 is connected to the exhaust channel 14 at a point between the upstream-side catalyst 28 and the downstream-side catalyst 30 as with the EGR channel 34, and the exhaust channel 14 is provided with a throttle valve 72. More specifically, the throttle valve 72 is installed in the exhaust channel 14 at a point between the connection point 34a to the EGR channel 34 and a connection point 70a to the communicating channel 70.
  • the throttle valve 72 is configured so that the opening degree thereof can be changed by the ECU 40 described above.
  • the pressure difference between the opposite sides of the open- close valve 52 (pressure difference between the connection points 34a and 70a) is ensured by using the throttle valve 72 disposed between the two connection points 34a and 70a to narrow the exhaust channel 14 in the operation of heating the EGR valve, rather than by using the pressure loss in the three way catalyst or the like.
  • Figure 8 is a flow chart showing a control routine performed by the ECU 40 to achieve the characteristic control according to the embodiment 2 of the present invention.
  • the same steps as the steps shown in Figure 3 in the embodiment 1 are denoted by the same reference numerals, and descriptions thereof will be omitted or simplified.
  • step 106 if the result of the determination in step 106 is positive, that is, the condition for performing the operation of heating the EGR valve is satisfied, the ECU 40 proceeds to step 200, in which the operation of heating the EGR valve is performed.
  • the operation of heating the EGR valve in this routine involves not only the operation of opening the open-close valve 52 but also an operation of throttling the flow of exhaust gas with the throttle valve 72. More specifically, the throttle valve 72 is controlled to have an opening degree that provides a pressure difference between the opposite sides of the open-close valve 52 that provides a flow rate of exhaust gas required for heating of the EGR valve 38.
  • the EGR valve 38 can be quickly heated, and introduction of the EGR gas can be started early in the state where there is no condensate water on the EGR valve 38 and its periphery.
  • the throttle valve 72 corresponds to the
  • the "controlling means" according to the second aspect of the present invention is provided by the ECU 40 performing a series of processings of the routine shown in Figure 8 described above.
  • communicating channel 80 in this configuration is connected to the exhaust channel 14 at a connection point 80a upstream of the connection point 34a to the EGR channel 34 along the flow of the exhaust gas in the exhaust channel 14 and between the upstream-side catalyst 28 and the downstream-side catalyst 30; and the throttle valve 72 is installed in the exhaust channel 14 at a point between the connection point 80a to the communicating channel 80 and the connection point 34a to the EGR channel 34.
  • Figure 10 is a flow chart showing a control routine performed by the ECU 40 to achieve the characteristic control according to the embodiment 3 of the present invention. As shown in Figure 10, this routine is the same as the routine shown in Figure 3 except that the routine does not include the processing of step 106. This is because if the configuration shown in Figure 9 is adopted, the exhaust gas is not cooled by the EGR cooler 36 before reaching the EGR valve 38 in the operation of heating the EGR valve.
  • Figure 11 is a diagram showing a modification of the configuration of the EGR device 32 and its periphery according to the embodiment 3 of the present invention.
  • the same components as those shown in Figure 9 described above are denoted by the same reference numerals, and descriptions thereof will be omitted or simplified.
  • the configuration shown in Figure 11 differs from the configuration shown in Figure 9 in that there is not the throttle valve 72, and a communicating channel 90 is connected to the exhaust channel 14 at a connection point 90a upstream of the upstream-side catalyst 28.
  • At least one device that lowers the pressure in the exhaust channel may be used instead of the throttle valve 72.
  • turbocharger 22 which uses exhaust gas energy as a driving force
  • turbocharger 22 has been described as an example of a supercharging device having a compressor that supercharges intake air.
  • any supercharging device having a compressor to supply supercharged intake air may be applied to the embodiment of the present invention.
  • the compressor according to the present invention may use the motive power from the crankshaft of the internal combustion engine as a driving force or use the power from an electric motor as a driving force, for example, as far as it can supercharge the intake air.
  • a supercharger i.e. a mechanical supercharger

Abstract

An EGR channel that connects an intake channel upstream of a compressor that supercharges intake air and an exhaust channel to each other, and an EGR valve that is disposed at an end of the EGR channel closer to the intake channel or at a midpoint in the EGR channel are provided. A communicating channel that connects the EGR channel and the exhaust channel to each other, and an open-close valve that opens and closes the communicating channel are provided. The communicating channel is connected to the EGR channel at a point immediately upstream of the EGR valve along the direction of the flow of the EGR gas and to the exhaust channel so that a downstream-side catalyst is disposed between the connection point between the communicating channel and the exhaust channel and the connection point between the EGR channel and the exhaust channel.

Description

Description
Title of Invention
INTERNAL COMBUSTION ENGINE
Technical Field
[0001]
The present invention relates to an internal combustion engine, and in particular, an internal combustion engine to which an EGR gas can be introduced.
Background Art
[0002]
For example, the patent literature 1 discloses a conventional internal combustion engine provided with a turbocharger. The internal combustion engine includes an intercooler that cools supercharged intake air and an EGR cooler that cools EGR gas introduced into an intake channel upstream of a compressor. The amount of EGR gas is controlled to prevent water condensation in the intercooler and the EGR cooler.
Citation List
Patent Literature
[0003]
[Patent Literature 1] Japanese Patent Laid-Open No. 2012-087779
Summary of Invention
Technical Problem
[0004]
Consider a configuration in which an EGR valve that adjusts the flow rate of EGR gas flowing in an EGR channel is provided at an end of the EGR channel closer to an intake channel or at a midpoint in the EGR channel. In the early stage of warm-up after starting from the cold state, water condensation tends to occur, so that the EGR valve is closed. Even if the EGR valve is closed, however, the EGR channel upstream of the EGR valve along the flow of the EGR gas is filled with exhaust gas as a result of exhaust pulsation, and gas exchange constantly occurs there. Therefore, moisture in the exhaust gas can condense on the cold EGR valve. Thus, in the cold state during which the EGR valve is closed, water condensation can occur on the surface of the EGR valve on the side of the exhaust channel and its vicinity.
[0005]
If the EGR valve is opened to introduce the EGR gas without any consideration on the occurrence of water condensation on the EGR valve described above, the condensate water flows into the intake channel. However, if introduction of the EGR gas is inhibited until the internal combustion engine is completely warmed up and the condensate water on the EGR valve disappears, the effect of the EGR gas introduction on improvement of the fuel consumption cannot be achieved.
[0006]
The present invention has been devised to solve the problems described above, and an object of the present invention is to provide an internal combustion engine that can quickly heat an EGR valve and start introducing EGR gas early in the state where there is no condensate water on the EGR valve and its periphery.
Solution to Problem
[0007]
According to a first aspect of the present invention, an internal combustion engine includes a compressor that supercharges intake air, an EGR channel, an EGR valve, a communicating channel, and an open-close valve. The EGR channel connects an intake channel upstream of the compressor and an exhaust channel to each other. The EGR valve is disposed at an end of the EGR channel closer to the intake channel or at a midpoint in the EGR channel and adjusts the flow rate of EGR gas flowing in the EGR channel. The communicating channel connects the EGR channel and the exhaust channel to each other. The open-close valve opens and closes the communicating channel. Further, the communicating channel is connected to the EGR channel at a point immediately upstream of the EGR valve along a direction of a flow of the EGR gas and to the exhaust channel at a point where there is a pressure difference with respect to the pressure in the exhaust channel at a connection point between the EGR channel and the exhaust channel or where the pressure difference is caused by an operation of a predetermined actuator.
[0008] According to a second aspect of the present invention, in the first aspect of the present invention, the internal combustion engine further includes controlling means for opening the open-close valve in a case where water condensation occurs on the EGR valve or there is a possibility that water condensation occurs on the EGR valve in the state where the EGR valve is closed.
[0009]
According to a third aspect of the present invention, in the second aspect of the present invention, the case where water condensation occurs on the EGR valve or there is a possibility that water condensation occurs on the EGR valve is a case where the temperature of the EGR valve is equal to or lower than a predetermined value.
[0010]
According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, at least one device that lowers the pressure in the exhaust channel is disposed in the exhaust channel at a point between the connection point between the EGR channel and the exhaust channel and the connection point between the communicating channel and the exhaust channel.
[0011]
According to a fifth aspect of the present invention, in any one of the first to third aspects of the present invention, a throttle valve that narrows the exhaust channel when the open-close valve is opened is disposed in the exhaust channel as the predetermined actuator at a point between the connection point between the EGR channel and the exhaust channel and the connection point between the communicating channel and the exhaust channel.
[0012]
According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, the internal combustion engine further includes an EGR cooler. The EGR cooler is disposed in the EGR channel upstream of the EGR valve along the flow of the EGR gas and cools the EGR gas flowing in the EGR channel. Further, the connection point between the communicating channel and the exhaust channel is located upstream of the connection point between the EGR channel and the exhaust channel along the flow of the exhaust gas in the exhaust channel.
Advantageous Effects of Invention [0013]
According to a first aspect of the present invention, if the open-close valve is opened in the cold state during which the EGR valve is closed, part of the exhaust gas flowing in the exhaust channel can flow through the EGR channel and the communicating channel while being in contact with the EGR valve. As a result, the EGR valve can be heated by the heat of the exhaust gas. In this way, occurrence of water condensation on the EGR valve can be prevented, or any condensate water can be removed (evaporated). Thus, there can be provided an internal combustion engine capable of quickly heating the EGR valve and starting introduction of EGR gas early in the state where there is no condensate water on the EGR valve and its periphery.
[0014]
According to a second and a third aspect of the present invention, in the case where water condensation has occurred, or can occur, on the EGR valve, the EGR valve can be heated by the heat of the exhaust gas introduced through the EGR channel and the communicating channel. In this way, occurrence of water condensation on the EGR valve can be prevented, or any condensate water can be removed (evaporated).
[0015]
According to a fourth aspect of the present invention, the device that lowers the pressure in the exhaust channel can be used to produce a flow of exhaust gas that flows in contact with the EGR valve when the open-close valve is opened in the state where the EGR valve is closed.
[0016]
According to a fifth aspect of the present invention, the throttle valve that narrows the exhaust channel when the open-close valve is opened can be used to produce a flow of exhaust gas that flows in contact with the EGR valve when the open-close valve is opened in the state where the EGR valve is closed.
[0017]
According to a sixth aspect of the present invention, a flow channel configuration can be formed in which the exhaust gas flows from the exhaust channel into the communicating channel and then into the EGR channel when the open-close valve is opened. As a result, when the EGR valve is heated in the case where a common configuration is adopted in which the EGR cooler is provided in the exhaust channel upstream of the EGR valve along the flow of the EGR gas, the exhaust gas can be prevented from being cooled by the EGR cooler before reaching the EGR valve. As a result, the temperature of the exhaust gas reaching the EGR valve when heating the EGR valve can be kept high. Therefore, effective heating of the EGR valve can be ensured.
[Brief Description of Drawings]
[0018]
[Figure 1] Figure 1 is a diagram for schematically illustrating a system configuration of an internal combustion engine according to an embodiment 1 of the present invention.
[Figure 2] Figure 2 is a diagram showing a characteristic configuration of an LPL EGR device and its periphery shown in Figure 1.
[Figure 3] Figure 3 is a flow chart showing a routine performed in the embodiment 1 of the present invention.
[Figure 4] Figure 4 is a diagram for illustrating a method of estimating the temperature of an EGR valve.
[Figure 5] Figure 5 is a diagram showing the effect of the operation of heating the EGR valve. [Figure 6] Figure 6 is a diagram showing another example of connection points of an EGR channel and a communicating channel to an exhaust channel.
[Figure 7] Figure 7 is a diagram showing a characteristic configuration of the EGR device and its periphery according to an embodiment 2 of the present invention.
[Figure 8] Figure 8 is a flow chart showing a routine performed in the embodiment 2 of the present invention.
[Figure 9] Figure 9 is a diagram showing a characteristic configuration of the EGR device and its periphery according to an embodiment 3 of the present invention.
[Figure 10] Figure 10 is a flow chart showing a routine performed in an embodiment 3 of the present invention.
[Figure 11] Figure 11 is a diagram showing a modification of the configuration of the EGR device and its periphery according to the embodiment 3 of the present invention.
Description of Embodiments
[0019]
Embodiment 1
[System Configuration of Internal Combustion Engine] Figure 1 is a diagram for schematically illustrating a system configuration of an internal combustion engine 10 according to an embodiment 1 of the present invention. The system according to this embodiment includes the internal combustion engine (a spark ignition engine, for example) 10. Each cylinder of the internal combustion engine 10 is in communication with an intake channel 12 and an exhaust channel 14.
[0020]
An air cleaner 16 is attached to the intake channel 12 at a point in the vicinity of an inlet thereof. An air flowmeter 18 that outputs a signal responsive to the flow rate of air sucked into the intake channel 12 and an intake air temperature sensor 20 that detects the temperature of the intake air are provided at a point downstream of, and in the vicinity of, the air cleaner 16.
[0021]
A compressor 22a of a turbocharger 22 is installed downstream of the air flowmeter 18. The compressor 22a is connected to and integrated with a turbine 22b disposed in the exhaust channel 14 by a connecting shaft. An intercooler 24 that cools air compressed by the compressor 22a is provided downstream of the compressor 22a. An electronically controlled throttle valve 26 is provided downstream of the intercooler 24.
[0022]
The exhaust channel 14 is provided with various kinds of catalysts for purifying exhaust gas at a point downstream of the turbine 22b. In this example, the exhaust channel 14 is provided with an upstream-side catalyst (S/C) 28 and a downstream-side catalyst (U/F) 30, which are both three way catalysts, the upstream-side catalyst 28 being located upstream of the downstream-side catalyst 30 along the flow of the exhaust gas.
[0023]
The internal combustion engine 10 shown in Figure 1 is provided with a low pressure loop (LPL) EGR device 32. The EGR device 32 includes an EGR channel 34 that connects the exhaust channel 14 downstream of the turbine 22b and the intake channel 12 upstream of the compressor 22a to each other. The EGR channel 34 is provided with an EGR cooler 36 and an EGR valve 38, the EGR cooler 36 being located upstream of the EGR valve 38 along the flow of the EGR gas introduced into the intake channel 12. The EGR cooler 36 is a water-cooling cooler provided for cooling the EGR gas flowing in the EGR channel 34. The EGR valve 38 is provided for adjusting the amount of EGR gas to be recirculated to the intake channel 12 through the EGR channel 34. A valve body 38a (see Figure 2) of the EGR valve 38 is heated by engine cooling water. The temperature of the engine cooling water supplied to the EGR cooler 36 is controlled to be higher than the dew point of the exhaust gas (EGR gas) passing through the EGR cooler 36.
[0024]
The system according to this embodiment is characterized by the configuration of the EGR device 32 and its periphery. The characteristic configuration will be described in detail with reference to Figure 2. The system shown in Figure 1 includes an electronic control unit (ECU) 40. Various types of sensors that detect the operational state of the internal combustion engine 10, such as the air flowmeter 18 and the intake air temperature sensor 20 described above, a crank angle sensor 42 that detects the engine speed, and a water temperature sensor 44 that detects the temperature of engine cooling water, are connected to an input part of the ECU 40. On the other hand, various types of actuators that control the operation of the internal combustion engine 10, such as the throttle valve 26 and the EGR valve 38 described above, a fuel injection valve 46 that injects fuel into a cylinder or intake port of the internal combustion engine 10, and an ignition device 48 that ignites an air-fuel mixture in the cylinder, are connected to an output part of the ECU 40. The ECU 40 controls the operation of the internal combustion engine 10 by making the various types of actuators operate based on outputs of the various types of sensors described above according to a predetermined program.
[0025]
[Characteristic Configuration of EGR Device and its Periphery in Embodiment 1]
Figure 2 is a diagram showing a characteristics configuration of the LPL EGR device 32 and its periphery shown in Figure 1. In this configuration, and end of the EGR channel 34 closer to the exhaust channel 14 is connected to the exhaust channel 14 at a point between the upstream-side catalyst 28 and the downstream-side catalyst 30. Although the EGR valve 38 is disposed at an end of the EGR channel 34 closer to the intake channel 12 in this example, the EGR valve 38 according to the present invention may be disposed at a midpoint on the EGR channel 34.
[0026]
In the early stage of warming up after starting from the cold state, the EGR valve 38 is typically closed in order to ensure good combustion and because water condensation tends to occur. Although the EGR valve 38 is closed, however, the EGR channel 34 upstream of the EGR valve 38 (on the side closer to the exhaust channel 14) along the flow of the EGR gas is filled with exhaust gas as a result of exhaust pulsation, and gas exchange constantly occurs there. Therefore, moisture in the exhaust gas can condense on the cold EGR valve 38. Thus, in the cold state during which the EGR valve 38 is closed, water condensation can occur on the surface of the EGR valve 38 on the side of the exhaust channel 14 and its vicinity.
[0027]
If the EGR valve 38 is opened to introduce the EGR gas without any consideration on the occurrence of water condensation on the EGR valve 38 described above, the condensate water flows into the intake channel 12. As a result, there is a possibility that a component of an intake system corrodes. In the case where the EGR gas is introduced to the intake channel 12 upstream of the compressor 22a as with the internal combustion engine 10 according to this embodiment, not only the corrosion of the compressor 22a but also wear (erosion) of the compressor 22a because of collision of the condensate water can occur. On the other hand, if introduction of the EGR gas is inhibited until the internal combustion engine 10 is completely warmed up and the condensate water on the EGR valve 38 disappears, it takes a long time to completely warm up the internal combustion engine 10 to remove (evaporate) the condensate water, and the effect of the EGR gas introduction on improvement of the fuel consumption cannot be achieved during that period.
[0028]
In view of this, in this embodiment, in order to quickly heat the EGR valve 38 and to introduce the EGR gas early in the state where there is no condensate water on the EGR valve 38 and its periphery, a communicating channel 50 and an open-close valve 52 shown in Figure 2 are provided. The communicating channel 50 connects the EGR channel 34 immediately upstream of the EGR valve 38 along the direction of the flow of the EGR gas and the exhaust channel 14 downstream of the downstream-side catalyst 30. The open-close valve 52 is disposed on the communicating channel 50 to open and close the communicating channel 50. The open-close valve 52 is electrically connected to the ECU 40 described above.
[0029]
The downstream-side catalyst 30 is disposed between a connection point 50a between the communicating channel 50 and the exhaust channel 14 and a connection point 34a between the EGR channel 34 and the exhaust channel 14. Therefore, it can be said that the communicating channel 50 is connected to the exhaust channel 14 at a point (the connection point 50a) at which there is a pressure difference with respect to the pressure in the exhaust channel at the connection point 34a to the EGR channel 34 because of the pressure loss by the downstream-side catalyst 30. In other words, in the exhaust channel 14, the downstream-side catalyst 30 as a device for lowering the pressure in the exhaust channel is disposed between the connection point 34a to the EGR channel 34 and the connection point 50a to the communicating channel 50.
[0030]
With the configuration described above, if the open-close valve 52 is opened in the cold state during which the EGR valve 38 is closed, part of the exhaust gas flowing through the exhaust channel 14 forms an exhaust gas flow that is fed back to the exhaust channel 14 downstream of the downstream-side catalyst 30 by passing through the EGR channel 34 and then the communicating channel 50. As described above, the connection point between the communicating channel 50 and the EGR channel 34 is immediately upstream of the EGR valve 38 along the direction of the flow of the EGR gas (when the EGR gas is introduced). Therefore, when the exhaust gas flows from the EGR channel 34 to the communicating channel 50, the exhaust gas flows while being in contact with the EGR valve 38. As a result, the EGR valve 38 can be heated by the heat of the exhaust gas. More specifically, since the heat of the exhaust gas that constantly flows and comes into contact with the EGR valve 38 can be used, the EGR valve 38 can be quickly heated compared with the case of using the heat of the exhaust gas that intermittently reaches the EGR valve 38 as a result of exhaust pulsation. As a result, occurrence of water condensation can be prevented, or any condensate water can be removed (evaporated).
[0031]
[Characteristic Control in Embodiment 1]
With the configuration described above, the cold EGR valve 38 can be quickly heated by opening the open-close valve 52 in the state where the EGR valve 38 is closed. Thus, in this embodiment, a control to open the open-close valve 52 is performed in the case where water condensation has occurred or can occur on the EGR valve 38 in the state where the EGR valve is closed. More specifically, the temperature of the EGR valve 38 is estimated, and in the case where the estimated temperature of the EGR valve 38 is equal to or lower than a predetermined valve XI , a control to open the open-close valve 52 (an operation of heating the EGR valve) is performed on the condition that the engine cooling water temperature THW satisfies a predetermined condition.
[0032] Figure 3 is a flow chart showing a control routine performed by the ECU 40 to achieve the characteristic control according to the embodiment 1 of the present invention. This routine is activated when the internal combustion engine is started from the cold state and repeatedly performed at a predetermined control cycle. The EGR valve 38 is closed when the internal combustion engine is started from the cold state.
[0033]
In the routine shown in Figure 3, in step 100, the ECU 40 calculates the estimated temperature of the EGR valve. In this example, the estimated temperature of the EGR valve is calculated as a function of the intake air temperature THA, the engine cooling water temperature THW and time, for example. Figure 4 is a diagram for illustrating a method of estimating the temperature of the EGR valve 38. The ECU 40 stores a map that determines a base value Teo of the temperature of the EGR valve 38 from a relationship between the intake air temperature THA and the engine cooling water temperature THW as shown in Figure 4. The base value Teo referred to herein means a steady temperature of the EGR valve 38 in the case where the intake air temperature THA and the engine cooling water temperature THW are arbitrary values.
[0034]
In this step 100, the value Teo for the intake air temperature THA detected by the intake air temperature sensor 20 and the engine cooling water temperature THW detected by the water temperature sensor 44 is determined by referring to the map shown in Figure 4. Then, based on the value Teo, a current temperature Tn of the EGR valve 38, which varies with the intake air temperature THA and the engine cooling water temperature THW with a temporal delay, is calculated according to the formula (1). In the formula (1), Tn-i denotes the previous value of the temperature of the EGR valve 38, and k denotes a preset smoothing coefficient (0 < k < 1). It is assumed that the water temperature sensor 44 measures, as the engine cooling water temperature THW, the temperature of the valve body 38a at a point where the temperature is correlated with the engine cooling water temperature.
[Expression 1]
Tn = Tn-i + (Teo - Tn.,) k ... (1)
[0035]
Next, the ECU 40 proceeds to step 102, in which it is determined whether or not the estimated temperature Tn of the EGR valve is equal to or lower than the predetermined valve XI . The predetermined valve XI is a temperature at which condensation starts occurring on the EGR valve 38 (that is, the dew point of the exhaust gas in the vicinity of the EGR valve 38). The processing of this step 102 is to determine whether or not water condensation has occurred or can occur on the EGR valve 38.
[0036]
If the result of the determination in step 102 is negative, the ECU 40 proceeds to step 104, and the open-close valve 52 is closed or the state where the open-close valve 52 is closed is maintained. That is, in this case, the operation of heating the EGR valve is not performed. On the other hand, if the result of the determination in step 102 is positive, the ECU 40 proceeds to step 106, in which it is determined whether or not the engine cooling water temperature THW is higher than a predetermined valve X2. The water temperature sensor 44 measures, as the engine cooling water temperature THW, a temperature at a point where the measured temperature is correlated with the engine cooling water temperature on the EGR cooler 36. The predetermined valve X2 corresponds to the value of the engine cooling water temperature THW detected by the water temperature sensor 44 when the engine cooling water temperature on the EGR cooler 36 is equal to the dew point of the exhaust gas in the vicinity of the EGR cooler 36.
[0037]
If the result of the determination in step 106 is negative, the ECU 40 proceeds to step 104, and the operation of heating the EGR valve is not performed. On the other hand, if the result of the determination in step 106 is positive, the ECU 40 proceeds to step 108, and the operation of heating the EGR valve is performed (that is, the open-close valve 52 is opened, or the state where the open-close valve 52 is opened is maintained).
[0038]
According to the routine shown in Figure 3 described above, if the estimated temperature of the EGR valve is equal to or lower than the predetermined valve XI and therefore it is determined that water condensation has occurred or can occur on the EGR valve 38, the operation of heating the EGR valve is performed on the condition that the result of the determination in step 106 is positive. In this way, the EGR valve 38 can be quickly heated, and introduction of the EGR gas can be started early in the state where there is no condensate water on the EGR valve 38 and its periphery.
[0039]
In addition, according to the routine described above, the operation of heating the EGR valve is permitted on the condition that the engine cooling water temperature is higher than the predetermined valve X2 and therefore it is determined that the engine cooling water temperature on the EGR cooler 36 is higher than the dew point of the EGR gas. In this way, the exhaust gas can be introduced to the EGR valve 38 and its periphery to heat the EGR valve 38 while ensuring that water condensation does not occur when the exhaust gas passes through the EGR cooler 36. However, the operation of heating the EGR valve according to the present invention may be performed when the condition concerning the engine cooling water temperature is not satisfied.
[0040]
Figure 5 is a diagram showing the effect of the operation of heating the EGR valve. As can be seen from Figure 5, by performing the control of the open-close valve 52 for the operation of heating the EGR valve, the temperature of the EGR valve 38 (the temperature of the surface of the head upstream along the flow of the EGR gas) in the case where the internal combustion engine is started from the cold state quickly increases compared with the case where the control is not performed. It can also be seen that this control shortens the time required for the temperature of the EGR valve 38 to reach the dew point of the EGR gas. In this way, this control can improve the heating of the EGR valve 38.
[0041]
In the embodiment 1 described above, the EGR channel 34 and the communicating channel 50 are arranged so that the downstream-side catalyst 30 is disposed in the exhaust channel 14 between the connection point 34a to the EGR channel 34 and the connection point 50a to the communicating channel 50. However, the arrangement that uses the pressure loss in the downstream-side catalyst 30 or other device in order to ensure an adequate flow rate of the exhaust gas in the operation of heating the EGR valve is not limited to that described above, and the arrangement shown in Figure 6 described below is also possible, for example.
[0042]
Figure 6 is a diagram showing another example of the connection points of the EGR channel and the communicating channel to the exhaust channel. In Figure 6, the same components as those shown in Figure 2 described above are denoted by the same reference numerals, and descriptions thereof will be omitted or simplified. An EGR device 60 shown in Figure 6 differs from the EGR device 32 shown in Figure 2 in that an EGR channel 62 is connected to the exhaust channel 14 upstream of the turbine 22b. The configuration shown in Figure 6 differs from the configuration shown in Figure 2 in that a communicating channel 64 is connected to the exhaust channel 14 downstream of the turbine 22b (and upstream of the upstream-side catalyst 28).
[0043]
As described above, the EGR channel 62 and the communicating channel 64 are arranged so that the turbine 22b is disposed in the exhaust channel 14 between a connection point 62a to the EGR channel 62 and a connection point 64a to the communicating channel 64. That is, in this example, the pressure loss in the turbine 22b is used for the operation of heating the EGR valve. In this way, the EGR device to which the present invention is applied is not limited to the LPL EGR device, such as the EGR device 32 described above, and the present invention can also be applied to a high pressure loop (HPL) EGR device. In addition, although the connection point 64a to the communicating channel 64 is a point in the exhaust channel 14 upstream of the upstream-side catalyst 28 in this example, the connection point 64a to the communicating channel 64 may be a point between the upstream-side catalyst 28 and the downstream-side catalyst 30 or a point downstream of the downstream-side catalyst 30. In this way, there may be a plurality of devices in the exhaust channel 14 between the connection points 62a and 64a. Such a device may be a device other than the three way catalyst or turbine as far as it can lower the pressure in the exhaust channel and appropriately produce a pressure difference between the connection points 62a and 64a. For example, the device may be an exhaust gas purifying catalyst other than the three way catalyst or a particulate filter that collects a particulate matter contained in the exhaust gas.
[0044]
In the embodiment 1 described above, the "controlling means" according to the second aspect of the present invention described earlier is provided by the ECU 40 performing a series of processings of the routine shown in Figure 3.
[0045]
Embodiment 2
Next, an embodiment 2 of the present invention will be described with reference to Figures 7 and 8.
[0046]
[Characteristic Configuration of EGR Device and its Periphery in Embodiment 2]
Figure 7 is a diagram showing a characteristic configuration of the EGR device 32 and its periphery according to the embodiment 2 of the present invention. In Figure 7, the same components as those shown in Figure 2 described above are denoted by the same reference numerals, and descriptions thereof will be omitted or simplified. The configuration shown in Figure 7 differs from the configuration shown in Figure 2 in that a communicating channel 70 is connected to the exhaust channel 14 at a point between the upstream-side catalyst 28 and the downstream-side catalyst 30 as with the EGR channel 34, and the exhaust channel 14 is provided with a throttle valve 72. More specifically, the throttle valve 72 is installed in the exhaust channel 14 at a point between the connection point 34a to the EGR channel 34 and a connection point 70a to the communicating channel 70. The throttle valve 72 is configured so that the opening degree thereof can be changed by the ECU 40 described above.
[0047]
With this configuration, the pressure difference between the opposite sides of the open- close valve 52 (pressure difference between the connection points 34a and 70a) is ensured by using the throttle valve 72 disposed between the two connection points 34a and 70a to narrow the exhaust channel 14 in the operation of heating the EGR valve, rather than by using the pressure loss in the three way catalyst or the like.
[0048]
[Characteristic Control in Embodiment 2]
Figure 8 is a flow chart showing a control routine performed by the ECU 40 to achieve the characteristic control according to the embodiment 2 of the present invention. In Figure 8, the same steps as the steps shown in Figure 3 in the embodiment 1 are denoted by the same reference numerals, and descriptions thereof will be omitted or simplified.
[0049]
In the routine shown in Figure 8, if the result of the determination in step 106 is positive, that is, the condition for performing the operation of heating the EGR valve is satisfied, the ECU 40 proceeds to step 200, in which the operation of heating the EGR valve is performed. The operation of heating the EGR valve in this routine involves not only the operation of opening the open-close valve 52 but also an operation of throttling the flow of exhaust gas with the throttle valve 72. More specifically, the throttle valve 72 is controlled to have an opening degree that provides a pressure difference between the opposite sides of the open-close valve 52 that provides a flow rate of exhaust gas required for heating of the EGR valve 38.
[0050] According to the routine shown in Figure 8 described above, again, the EGR valve 38 can be quickly heated, and introduction of the EGR gas can be started early in the state where there is no condensate water on the EGR valve 38 and its periphery.
[0051]
In the embodiment 2 described above, the throttle valve 72 corresponds to the
"predetermined actuator" according to the first aspect of the present invention. In the embodiment 2 described above, the "controlling means" according to the second aspect of the present invention is provided by the ECU 40 performing a series of processings of the routine shown in Figure 8 described above.
[0052]
Embodiment 3
Next, an embodiment 3 of the present invention will be described with reference to Figures 9 and 10.
[0053]
[Characteristic Configuration of EGR Device and its Periphery in Embodiment 3]
Figure 9 is a diagram showing a characteristic configuration of the EGR device 32 and its periphery according to the embodiment 3 of the present invention. In Figure 9, the same components as those shown in Figure 7 described above are denoted by the same reference numerals, and descriptions thereof will be omitted or simplified. The configuration shown in Figure 9 differs from the configuration shown in Figure 7 in the following points: a
communicating channel 80 in this configuration is connected to the exhaust channel 14 at a connection point 80a upstream of the connection point 34a to the EGR channel 34 along the flow of the exhaust gas in the exhaust channel 14 and between the upstream-side catalyst 28 and the downstream-side catalyst 30; and the throttle valve 72 is installed in the exhaust channel 14 at a point between the connection point 80a to the communicating channel 80 and the connection point 34a to the EGR channel 34.
[0054]
With the configuration shown in Figure 7 (according to the embodiment 2), when the open-close valve 52 is opened in the state where the EGR valve 38 is closed and the flow of the exhaust gas is throttled by the throttle valve 72, a flow channel configuration is established in which part of the exhaust gas flows from the exhaust channel 14 into the EGR channel 34, passes through the communicating channel 70 and then flows back to the exhaust channel 14. As shown in the configuration in Figure 7, the EGR cooler is typically disposed in the EGR channel at a point upstream of the EGR valve along the flow of the EGR gas. Therefore, in the configuration shown in Figure 7, in the operation of heating the EGR valve, the exhaust gas is cooled by the EGR cooler 36 before reaching the EGR valve 38, and heating of the EGR valve 38 may become less effective.
[0055]
To the contrary, with the configuration shown in Figure 9, when the open-close valve 52 is opened in the state where the EGR valve 38 is closed and the flow of the exhaust gas is throttled by the throttle valve 72, a reverse flow channel configuration is established in which part of the exhaust gas flows from the exhaust channel 14 into the communicating channel 80, passes through the EGR channel 34 and then flows back to the exhaust channel 14. As a result, the exhaust gas heats the EGR valve 38 before passing through the EGR cooler 36. Thus, the temperature of the exhaust gas reaching the EGR valve 38 in the operation of heating the EGR valve can be kept high without modifying the basic configuration in which the EGR cooler 36 is disposed upstream of the EGR valve 38 along the flow of the EGR gas. Therefore, effective heating of the EGR valve 38 can be ensured. As a measure to keep the temperature of the exhaust gas reaching the EGR valve 38 high, a flow channel configuration that involves no EGR cooler unlike this configuration is also possible. Compared with such a configuration, however, according to the configuration shown in Figure 9, the engine cooling water can be more quickly heated because exhaust heat can be recovered by the EGR cooler 36 when the EGR valve 38 is being heated in the cold state.
[0056]
[Characteristic Control in Embodiment 3]
Figure 10 is a flow chart showing a control routine performed by the ECU 40 to achieve the characteristic control according to the embodiment 3 of the present invention. As shown in Figure 10, this routine is the same as the routine shown in Figure 3 except that the routine does not include the processing of step 106. This is because if the configuration shown in Figure 9 is adopted, the exhaust gas is not cooled by the EGR cooler 36 before reaching the EGR valve 38 in the operation of heating the EGR valve.
[0057]
In the embodiment 3 described above, an example has been described in which the throttle valve 72 is disposed in the exhaust channel 14 between the connection point 80a to the communicating channel 80 and the connection point 34a to the EGR channel 34. However, the arrangement in which the communicating channel is connected to the exhaust channel 14 at a connection point upstream of the EGR channel is not limited to the arrangement described above, and the arrangement shown in Figure 1 1 described below is also possible, for example.
[0058]
Figure 11 is a diagram showing a modification of the configuration of the EGR device 32 and its periphery according to the embodiment 3 of the present invention. In Figure 1 1, the same components as those shown in Figure 9 described above are denoted by the same reference numerals, and descriptions thereof will be omitted or simplified. The configuration shown in Figure 11 differs from the configuration shown in Figure 9 in that there is not the throttle valve 72, and a communicating channel 90 is connected to the exhaust channel 14 at a connection point 90a upstream of the upstream-side catalyst 28. As illustrated in the configuration in Figure 1 1, in the configuration in which the communicating channel is connected to the exhaust channel 14 at a connection point upstream of the EGR channel, at least one device (a three way catalyst, for example) that lowers the pressure in the exhaust channel may be used instead of the throttle valve 72.
[0059]
In the embodiment 3 described above, the "controlling means" according to the second aspect of the present invention is provided by the ECU 40 performing a series of processings of the routine shown in Figure 10 described above.
[0060]
In the embodiments 1 to 3 and the modifications thereof described above, the EGR device 32 or 60 provided with the EGR cooler 36 in the EGR channel 34 or 62 has been described as examples. However, the present invention can equally be applied to a configuration in which no EGR cooler is provided in the EGR channel.
[0061]
In the embodiments 1 to 3 and the modifications thereof described above, the
turbocharger 22, which uses exhaust gas energy as a driving force, has been described as an example of a supercharging device having a compressor that supercharges intake air. However, any supercharging device having a compressor to supply supercharged intake air may be applied to the embodiment of the present invention. The compressor according to the present invention may use the motive power from the crankshaft of the internal combustion engine as a driving force or use the power from an electric motor as a driving force, for example, as far as it can supercharge the intake air. For example, in the internal combustion engine 10, a supercharger (i.e. a mechanical supercharger) may be installed instead of the turbocharger 22.
Reference Signs List
[0062]
10 internal combustion engine
12 intake channel
14 exhaust channel
16 air cleaner
18 air flowmeter
20 intake air temperature sensor
22 turbocharger
22a compressor
22b turbine
24 intercooler
26 throttle valve
28 upstream-side catalyst
30 downstream-side catalyst
32, 60 EGR device
34, 62 EGR channel
34a, 62a connection point between EGR channel and exhaust channel
36 EGR cooler
38 EGR valve
38a valve body
40 ECU (electronic control unit)
42 crank angle sensor
44 water temperature sensor
46 fuel injection valve
48 ignition device
50, 64, 70, 80, 90 communicating channel 50a, 64a, 70a, 80a, 90a connection point between communicating channel and exhaust channel
52 open-close valve
72 throttle valve

Claims

Claims
[Claim 1]
An internal combustion engine, comprising:
a compressor that supercharges intake air;
an EGR channel that connects an intake channel upstream of the compressor and an exhaust channel to each other;
an EGR valve that is disposed at an end of the EGR channel closer to the intake channel or at a midpoint in the EGR channel and adjusts the flow rate of EGR gas flowing in the EGR channel;
a communicating channel that connects the EGR channel and the exhaust channel to each other; and
an open-close valve that opens and closes the communicating channel,
wherein the communicating channel is connected to the EGR channel at a point immediately upstream of the EGR valve along a direction of a flow of the EGR gas and to the exhaust channel at a point where there is a pressure difference with respect to the pressure in the exhaust channel at a connection point between the EGR channel and the exhaust channel or where the pressure difference is caused by an operation of a predetermined actuator.
[Claim 2]
The internal combustion engine according to Claim 1 , further comprising controlling means for opening the open-close valve in a case where water condensation occurs on the EGR valve or there is a possibility that water condensation occurs on the EGR valve in the state where the EGR valve is closed.
[Claim 3]
The internal combustion engine according to Claim 2, wherein the case where water condensation occurs on the EGR valve or there is a possibility that water condensation occurs on the EGR valve is a case where the temperature of the EGR valve is equal to or lower than a predetermined value.
[Claim 4]
The internal combustion engine according to any one of Claims 1 to 3, wherein at least one device that lowers the pressure in the exhaust channel is disposed in the exhaust channel at a point between the connection point between the EGR channel and the exhaust channel and the connection point between the communicating channel and the exhaust channel.
[Claim 5]
The internal combustion engine according to any one of Claims 1 to 3, wherein a throttle valve that narrows the exhaust channel when the open-close valve is opened is disposed in the exhaust channel as the predetermined actuator at a point between the connection point between the EGR channel and the exhaust channel and the connection point between the communicating channel and the exhaust channel.
[Claim 6]
The internal combustion engine according to any one of Claims 1 to 5, further comprising:
an EGR cooler that is disposed in the EGR channel upstream of the EGR valve along the flow of the EGR gas and cools the EGR gas flowing in the EGR channel,
wherein the connection point between the communicating channel and the exhaust channel is located upstream of the connection point between the EGR channel and the exhaust channel along the flow of the exhaust gas in the exhaust channel.
PCT/JP2015/058153 2014-03-18 2015-03-12 Internal combustion engine WO2015141756A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019121284A1 (en) * 2017-12-20 2019-06-27 Pierburg Gmbh Control valve for an internal combustion engine, and method for controlling a control valve
US10968872B2 (en) 2019-03-18 2021-04-06 Toyota Jidosha Kabushiki Kaisha Exhaust gas recirculation valve warming device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018119465A (en) * 2017-01-25 2018-08-02 アイシン精機株式会社 Internal combustion engine

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0104524A1 (en) * 1982-09-24 1984-04-04 Robert Bosch Gmbh Device for the recirculation of exhaust gas in an internal-combustion engine
EP0913561A2 (en) * 1997-10-31 1999-05-06 Valeo Thermique Moteur S.A. Exhaust and recirculation line of the exhaust gas of an internal combustion engine
DE10115594A1 (en) * 2000-03-30 2001-10-11 Aisin Seiki Exhaust gas feedback system has connecting line between output region and combination region, exhaust gas control valve controlling quantity of exhaust gas fed back to connecting line
US20070084206A1 (en) * 2005-10-17 2007-04-19 Lew Mae L EGR cooler purging apparatus and method
DE102010044923A1 (en) * 2010-09-10 2012-04-19 Att Automotivethermotech Gmbh Method for operating cooling and heating circuit for e.g. large passenger car, involves maintaining effective combustion fresh air mass flow smaller than reference fresh air mass flow for reducing cabin heat power deficit
WO2013167823A1 (en) * 2012-05-09 2013-11-14 Valeo Systemes De Controle Moteur System for recovering energy in an exhaust gas circuit

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0104524A1 (en) * 1982-09-24 1984-04-04 Robert Bosch Gmbh Device for the recirculation of exhaust gas in an internal-combustion engine
EP0913561A2 (en) * 1997-10-31 1999-05-06 Valeo Thermique Moteur S.A. Exhaust and recirculation line of the exhaust gas of an internal combustion engine
DE10115594A1 (en) * 2000-03-30 2001-10-11 Aisin Seiki Exhaust gas feedback system has connecting line between output region and combination region, exhaust gas control valve controlling quantity of exhaust gas fed back to connecting line
US20070084206A1 (en) * 2005-10-17 2007-04-19 Lew Mae L EGR cooler purging apparatus and method
DE102010044923A1 (en) * 2010-09-10 2012-04-19 Att Automotivethermotech Gmbh Method for operating cooling and heating circuit for e.g. large passenger car, involves maintaining effective combustion fresh air mass flow smaller than reference fresh air mass flow for reducing cabin heat power deficit
WO2013167823A1 (en) * 2012-05-09 2013-11-14 Valeo Systemes De Controle Moteur System for recovering energy in an exhaust gas circuit

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019121284A1 (en) * 2017-12-20 2019-06-27 Pierburg Gmbh Control valve for an internal combustion engine, and method for controlling a control valve
US10968872B2 (en) 2019-03-18 2021-04-06 Toyota Jidosha Kabushiki Kaisha Exhaust gas recirculation valve warming device

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