WO2011099326A1 - Engine - Google Patents

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Publication number
WO2011099326A1
WO2011099326A1 PCT/JP2011/050683 JP2011050683W WO2011099326A1 WO 2011099326 A1 WO2011099326 A1 WO 2011099326A1 JP 2011050683 W JP2011050683 W JP 2011050683W WO 2011099326 A1 WO2011099326 A1 WO 2011099326A1
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WO
WIPO (PCT)
Prior art keywords
engine
turbocharger
electric motor
compressor
turbochargers
Prior art date
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PCT/JP2011/050683
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French (fr)
Japanese (ja)
Inventor
徳永　裕之
平木　彦三郎
昭浩 大澤
昇 飯田
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株式会社小松製作所
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Publication of WO2011099326A1 publication Critical patent/WO2011099326A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
    • F02B37/013—Engines characterised by provision of pumps driven at least for part of the time by exhaust with exhaust-driven pumps arranged in series
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
    • F02B37/004—Engines characterised by provision of pumps driven at least for part of the time by exhaust with exhaust drives arranged in series
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
    • F02B37/04—Engines with exhaust drive and other drive of pumps, e.g. with exhaust-driven pump and mechanically-driven second pump
    • F02B37/10—Engines with exhaust drive and other drive of pumps, e.g. with exhaust-driven pump and mechanically-driven second pump at least one pump being alternatively or simultaneously driven by exhaust and other drive, e.g. by pressurised fluid from a reservoir or an engine-driven pump
    • 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
    • F02M26/08—EGR systems specially adapted for supercharged engines for engines having two or more intake charge compressors or exhaust gas turbines, e.g. a turbocharger combined with an additional compressor
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • the present invention relates to an engine, and more specifically to a multi-stage supercharged engine equipped with an EGR (Exhaust Gas Recirculation) device.
  • EGR Exhaust Gas Recirculation
  • a supercharged engine equipped with an EGR device that suppresses the generation of NOx by lowering the internal combustion temperature of the air-fuel mixture is known.
  • a part of the exhaust gas can be returned to the supply side by the EGR device.
  • the engine operating state for example, when the engine is operated at a medium to high speed and in a high load region is used.
  • the supply pressure by a turbocharger such as a turbocharger may be higher than the exhaust gas pressure. In this case, the exhaust gas does not return to the supply side, and the EGR rate decreases.
  • turbochargers are provided in series to perform multi-stage supercharging, and all turbochargers are provided with electric motors to generate or drive electric motors, so that the air supply pressure is controlled regardless of the engine operating state.
  • the turbocharger provided with the electric motor has a lower rotational speed of the turbine and the compressor than the turbocharger without the electric motor because of the rotor of the electric motor.
  • the capacity (power generation amount and driving amount) of the motor also decreases.
  • the high-pressure stage turbocharger is provided with an electric motor, the low-pressure stage turbocharger is substantially responsible for most of the motor capacity necessary for controlling the EGR rate. End up. That is, when an electric motor is provided in the turbocharger on the high pressure stage side, there is a problem that the effect may not be obtained sufficiently.
  • An object of the present invention is to provide a compact multistage supercharged engine that can enjoy the effect of an electric motor provided in a turbocharger.
  • An engine of the present invention is a multi-stage supercharged engine, and an EGR device having an EGR passage that extracts a part of exhaust gas from an exhaust passage of the engine body and returns it to the air supply passage of the engine body;
  • a compressor that sucks and pressurizes and supplies the compressor to the engine body, and a plurality of turbochargers each having a turbine that drives the compressor, and the plurality of turbochargers provide rotational driving force to the compressor and the turbine.
  • At least one first turbocharger having an electric motor provided so as to be able to exchange, and at least one second turbocharger provided in series with the first turbocharger and not having the electric motor.
  • One of the plurality of turbochargers is provided on a side closest to the engine body of the supply passage. And wherein the are.
  • the engine is a two-stage supercharging type in which each of the first and second turbochargers is provided as the plurality of turbochargers.
  • At least one of the traveling body for self-running, the working machine for work, and the revolving body on which the work machine is mounted has generated electric power generated using the engine as a drive source. It is desirable that the engine is a hybrid type construction machine that is driven by an electric motor.
  • the turbocharger includes a plurality of turbochargers including a first turbocharger having an electric motor and a second turbocharger not having an electric motor. Since one of the second turbochargers among the superchargers is provided on the side of the air supply passage closest to the engine body, a turbocharger on the high pressure stage side close to the engine body and its While avoiding the increase in size of the auxiliary machine, it is possible to improve the transient response of the engine or to secure a sufficient EGR rate. Therefore, the effect of the electric motor provided in the turbocharger can be enjoyed, and a compact multistage supercharged engine can be obtained.
  • turbocharger when the engine is a two-stage turbocharger in which each of the first and second turbochargers is provided as the plurality of turbochargers, a minimum number of turbochargers is provided.
  • a turbocharger can constitute a multi-stage supercharged engine. Therefore, the engine of the present invention can be obtained with the simplest configuration.
  • the engine of the present invention is a hybrid construction machine engine, the above-described effects of the present invention can be obtained particularly remarkably.
  • the response delay of other hydraulic drive parts tends to be conspicuous as the traveling body, work machine, and swivel body are driven by an electric motor.
  • Some engines are also required to have higher responsiveness than conventional hydraulically driven construction machines.
  • the engine displacement and the turbocharger turbine size are significantly larger than passenger cars and commercial vehicles, so the time lag during supercharging is large, which is required for hybrid construction machinery.
  • the engine's transient response could not be fully met.
  • the engine of the present invention is used, sufficient transient response required in a hybrid construction machine can be obtained.
  • the engine of construction machinery has a very high ratio of driving at a high load compared to passenger cars and commercial vehicles, and the engine is frequently subjected to rapid acceleration / deceleration, so that the generation of NOx can be suppressed. was difficult.
  • the engine of the present invention is used, a high EGR rate can be realized, and therefore, it is possible to promote suppression of NOx generation that is also required for a hybrid construction machine.
  • FIG. 1 is a block diagram showing a system configuration of a construction machine according to an embodiment of the present invention.
  • the schematic diagram which shows the engine mounted in the construction machine.
  • the operation movement flowchart of an engine.
  • a power shovel 1 as a construction machine includes an engine 2 as a drive source.
  • a generator motor 3 and a pair of hydraulic pumps 4, 4 are connected in series to the output shaft of the engine 2, and are driven by the engine 2.
  • the work machine 11 in the excavator 1 is composed of a boom, an arm, and a bucket (not shown), and allows hydraulic oil to flow into and out of the boom cylinder 12, the arm cylinder 13, and the bucket cylinder 14 that are respectively provided.
  • the work machine 11 is operated by hydraulic pressure.
  • the vehicle body of the excavator 1 is provided with a pair of crawler-type lower traveling bodies in addition to the above-described upper revolving body 9 being turnably installed, although the detailed illustration is omitted.
  • the lower traveling body has a traveling hydraulic motor 15 for driving a sprocket that meshes with the crawler.
  • the hydraulic oil from the hydraulic pump 4 also controls the control valve 10 with respect to these traveling hydraulic motors 15. Supplied through.
  • the power shovel 1 of the present embodiment is a hybrid construction machine that drives the upper swing body 9 to swing with electric energy and drives the work implement 11 and the lower traveling body with hydraulic pressure.
  • Each configuration described above is mounted on the upper swing body 9 except for the traveling hydraulic motor 15, and rotates together with the upper swing body 9.
  • the upper revolving structure 9 of the power shovel 1 is provided with a cab that is operated by an operator.
  • a cab In such a cab, there are provided an operator's seat, a fuel dial for setting a fuel supply amount to the engine 2, levers, pedals, monitors, and other switches.
  • the upper swing body 9 is provided with a control box in which the inverter 5 and a swing control device 30 to be described later are accommodated, and an engine controller 40 for controlling the operation of the engine 2.
  • FIG. 1 shows a working machine 11 installed in a cab, a working machine lever 16 for operation, and a turning lever 17 for turning operation.
  • the work machine lever 16 includes a PPC (Proportional Pressure Control) valve.
  • the work machine lever 16 performs the switching operation of the control valve 10 by the pilot pressure generated by the PPC valve, and operates the work machine 11.
  • the turning lever 17 includes a potentiometer and the like so as to output a lever signal corresponding to the tilt angle to the turning control device 30.
  • the turning control device 30 controls the turning operation of the upper turning body 9, and is composed of various hardware and software used in computer technology.
  • the turning control device 30 of the present embodiment is provided in a form mounted on the inverter 5 and is electrically connected to the inverter 5.
  • the engine controller 40 receives detection signals such as a fuel dial set position, an accelerator pedal opening, an engine rotation speed, and a fuel injection amount from detection means (not shown), and the operation state of the engine 2 is detected by these detection signals. The amount of fuel injected into the combustion chamber and the fuel injection timing are controlled according to the state.
  • the engine controller 40 also controls operations of an electric motor 254 and an EGR valve 292 (see FIG. 2), which will be described later.
  • the engine 2 is a diesel engine in the present embodiment, and includes an engine body 20 in which a plurality of combustion chambers are formed, an air supply passage 21 that supplies air to the combustion chambers of the engine body 20, an engine body 20, An air supply manifold 22 that is provided between the air passages 21 and distributes air from the air supply passages 21 to the combustion chambers, an exhaust passage 23 that discharges exhaust gas from the engine body 20, and between the engine body 20 and the exhaust passages 23.
  • An exhaust manifold 24 that collects exhaust gas and flows into the exhaust passage 23, a first turbocharger 25 that supercharges the outside air sucked into the air supply passage 21, and the first turbocharger 25 compresses the exhaust gas. Compressed by an intercooler 26 that cools air, a second turbocharger 27 that further compresses compressed air from the first turbocharger 25, and a second turbocharger 27 The the aftercooler 28 for cooling air, and a EGR device 29 for suppressing the generation of NOx.
  • the first turbocharger 25 includes a turbine 251 that rotates with exhaust energy of exhaust gas, a compressor 252 that rotates together with the turbine 251 and compresses outside air, and a rotating shaft that connects the turbine 251 and the compressor 252.
  • 253 includes a turbine 251 and a compressor 252 and an electric motor 254 provided so as to be able to transmit and receive a rotational driving force.
  • the electric motor 254 can also function as a generator, and switching between the electric function and the power generation function is performed by the engine controller 40.
  • the air supply passage 21 communicates from the compressor 252 outlet to the second turbocharger 27, and an intercooler 26 is provided between the compressor 252 and the second turbocharger 27 in the air supply passage 21.
  • the second turbocharger 27 is provided on the high-pressure stage side closer to the engine body 20 than the first turbocharger 25. Unlike the first turbocharger 25, the second turbocharger 27 is a turbocharger that does not have an electric motor, and includes a turbine 271 and a compressor 272 that are directly connected to each other by a rotating shaft 273. . The outlet of the compressor 272 and the supply manifold 22 communicate with each other through the supply passage 21, and an after cooler 28 is provided between the compressor 272 and the supply manifold 22 in the supply passage 21.
  • the EGR device 29 includes an EGR passage 291 that branches from the exhaust passage 23 and communicates with the downstream side of the air supply passage 21 (downstream side after the aftercooler 28).
  • the EGR passage 291 is provided with an EGR valve 292 that opens and closes the EGR passage 291 and an EGR cooler 293 that cools the exhaust gas from the exhaust manifold 24.
  • the opening / closing control of the EGR valve 292 is performed by the engine controller 40 based on a detection signal from a NOx amount detection means (not shown) provided in the exhaust passage 23 or the exhaust manifold 24.
  • exhaust gas is generated by internal combustion (S 8), and the generated exhaust gas passes through the exhaust manifold 24 and is distributed toward the turbine 271 and the EGR passage 291 of the second turbocharger 27. (S9).
  • the exhaust gas distributed to the EGR passage 291 is cooled by the EGR cooler 293 (S10) and then mixed with the compressed air from the second turbocharger 27 (S6).
  • the exhaust gas distributed to the turbine 271 of the second turbocharger 27 drives the turbine 271 on the high-pressure stage side (S11).
  • the driving force of the turbine 271 is transmitted to the compressor 272 and further compresses the compressed air from the first turbocharger 25 as described above (S4).
  • the exhaust gas that has driven the turbine 271 of the second turbocharger 27 drives the low-pressure stage turbine 251 by the first turbocharger 25 (S12), and is discharged from the exhaust passage 23 (S13).
  • the driving force of the turbine 251 at this time is transmitted to the electric motor 254 to drive the electric motor 254.
  • the engine controller 254 when the engine controller 40 determines that the engine 2 is in an acceleration operation state based on information such as a fuel dial setting position and an accelerator pedal opening (not shown), the engine controller 254 causes the motor 254 to function as an electric motor. If it determines with it not being in an acceleration driving
  • the exhaust gas pressure, the supply pressure, and the EGR rate are generated or driven by the electric motor 254 of the first turbocharger 25.
  • the exhaust gas pressure of the exhaust manifold 24 can be made significantly higher than the supply pressure of the supply manifold 22. Accordingly, the amount of exhaust gas flowing through the EGR cooler 293 to the air supply manifold 22 increases, so that the EGR rate can be increased.
  • the motor 254 of the first turbocharger 25 is caused to function as an electric motor and the turbine 251 is driven, the exhaust gas pressure decreases and the supply air pressure increases, so the EGR rate decreases. In this way, the EGR rate can be controlled according to the amount of power generation or driving amount of the electric motor 254.
  • the motor 254 of the first turbocharger 25 is made to function as an electric motor during the acceleration operation of the engine 2 to assist the rotation of the compressor 252, the supercharging pressure will rise faster than when there is no assist. Become. Therefore, the transient response of the engine 2 can be improved.
  • the fuel consumption can be improved by returning the electric power generated by the electric motor 254 of the first turbocharger 25 to the electric power supply system including a battery, a capacitor, and the like. That is, in the case of the power shovel 1 of the present embodiment, the generator motor 3 coupled to the output shaft of the engine 2 is driven by the electric power generated by the first turbocharger 25 to assist the drive of the engine 2. , Fuel economy can be improved. On the contrary, the rotation of the compressor 252 can be assisted by driving the electric motor 254 of the first turbocharger 25 using the electric power generated by the generator motor 3.
  • the resonance rotational speed is reduced by the amount provided by the electric motor 254.
  • the turbine 271 and the compressor are originally provided. Since the maximum rotational speed of 272 is low, the maximum rotational speed does not exceed the resonant rotational speed even when the electric motor 254 is provided.
  • the second turbocharger 27 on the high-pressure stage side is a turbocharger that does not have an electric motor and has a high resonance speed
  • the turbine and the compressor can be driven at a high speed, and the exhaust gas The pressure and the supply air pressure can be sufficiently increased. For this reason, a high EGR rate can be ensured, and engine output can be improved by supercharging.
  • auxiliary equipment such as cooling equipment related to the second turbocharger 27 can be used without increasing its size.
  • the second turbocharger 27 that does not have an electric motor is provided on the high-pressure stage side closest to the engine body 20. Since the first turbocharger 25 provided with the electric motor 254 is provided on the low pressure stage side away from the engine body 20, the engine 2 becomes larger with the adoption of the electric motor for the turbocharger, The above-described effects of the electric motor provided in the turbocharger can be enjoyed without increasing the cost.
  • the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
  • the engine 2 is a diesel engine, but may be another engine such as a gasoline engine.
  • the engine 2 employs the two-stage supercharging system using the first turbocharger 25 and the second turbocharger 27, but the supercharger closest to the engine body 20 generates power. If the turbocharger does not have a machine, the engine 2 may be provided with three or more turbochargers. If three or more superchargers are provided in series, the supercharging pressure of the engine 2 can be further increased, so that the EGR rate can be further improved.
  • the electric motor 254 is provided on the rotary shaft 253 between the turbine 251 and the compressor 252 of the first turbocharger 25, but is not limited thereto.
  • the electric motor 254 only needs to be provided so as to be able to exchange rotational driving force with the turbine 251 and the compressor 252.
  • the first turbocharger 25 rotates with the turbine 251 and the compressor 252 using a power transmission mechanism such as a gear. The driving force may be exchanged.
  • the upper swing body 9 is driven to swing with electric energy, and the work implement 11 and the lower traveling body are driven with hydraulic pressure, but the present invention is not limited thereto. That is, as long as it is a hybrid type that drives the traveling body, the work machine, the turning body, and the like with electric energy and hydraulic pressure, it is arbitrary which electric power and hydraulic pressure are allocated to drive of the driven body.
  • the hybrid construction machine is not limited to the power shovel 1, and may be another construction machine such as a wheel loader or a dump truck.
  • the working machine may be driven by hydraulic pressure and the traveling body may be driven by electric energy.
  • the vessel is driven by hydraulic pressure and the traveling body may be driven by electric energy. That's fine.
  • the working machine may be driven by electric energy and the traveling body may be driven hydraulically.
  • the present invention can be used not only for construction machines such as power shovels but also for work machines such as cranes having an upper rotating body.
  • SYMBOLS 1 Power excavator which is a hybrid type construction machine, 2 ... Engine, 20 ... Engine main body, 21 ... Air supply passage, 23 ... Exhaust passage, 25 ... 1st turbocharger, 27 ... 2nd turbocharger, 29 ... EGR device, 40 ... engine controller, 251,271 ... turbine, 252,272 ... compressor, 254 ... electric motor, 291 ... EGR passage.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Supercharger (AREA)

Abstract

A multi-stage supercharged engine (2) comprises: an EGR device (29) which is provided with an EGR path (291) for extracting a portion of the exhaust gas from the exhaust path (23) of the engine body (20) and returning the gas to the air supply path (21) of the engine body (20); and turbo superchargers (25, 27) which are provided with compressors (252, 272) for sucking and pressurizing the outside air and supplying the air to the engine body (20), and also with turbines (251, 271). The turbo superchargers (25, 27) are the first turbo supercharger (25) which has an electric motor (254) capable of supplying and receiving rotational driving power to and from both the compressor (252) and the turbine (251), and the second turbo supercharger (27) which has no electric motor. The second turbo supercharger (27) among the turbo superchargers (25, 27) is provided at a position in the air supply path (21) closer to the engine body (20) than the other.

Description

エンジンengine
　本発明は、エンジンに係り、より具体的には、ＥＧＲ（Exhaust Gas Recirculation）装置を備えた多段過給式のエンジンに関する。 The present invention relates to an engine, and more specifically to a multi-stage supercharged engine equipped with an EGR (Exhaust Gas Recirculation) device.
　従来、混合気の内燃温度を下げてＮＯｘの発生を抑制するＥＧＲ装置を備えた過給式のエンジンが知られている。このようなエンジンでは、ＥＧＲ装置により、排気ガスの一部を給気側に戻すことができるのであるが、エンジンを例えば中高速でかつ高負荷領域で運転する場合のように、エンジンの運転状態によってはターボ過給機等の過給機による給気圧力が排気ガス圧力よりも高くなることがある。この場合には、排気ガスが給気側に戻らずに、ＥＧＲ率が低下してしまうことになる。 Conventionally, a supercharged engine equipped with an EGR device that suppresses the generation of NOx by lowering the internal combustion temperature of the air-fuel mixture is known. In such an engine, a part of the exhaust gas can be returned to the supply side by the EGR device. However, the engine operating state, for example, when the engine is operated at a medium to high speed and in a high load region is used. Depending on the case, the supply pressure by a turbocharger such as a turbocharger may be higher than the exhaust gas pressure. In this case, the exhaust gas does not return to the supply side, and the EGR rate decreases.
　そこで、複数のターボ過給機を直列に設けて多段過給するとともに、全てのターボ過給機に電動機を設けて電動機を発電または駆動させることで、エンジンの運転状態にかかわらず、給気圧力および排気ガス圧力を適切な状態に調節して、ＥＧＲ率を確保することが提案されている（例えば特許文献１参照）。 Therefore, a plurality of turbochargers are provided in series to perform multi-stage supercharging, and all turbochargers are provided with electric motors to generate or drive electric motors, so that the air supply pressure is controlled regardless of the engine operating state. In addition, it has been proposed to secure the EGR rate by adjusting the exhaust gas pressure to an appropriate state (see, for example, Patent Document 1).
米国特許第６３２４８４６号明細書US Pat. No. 6,324,846
　特許文献１に記載のような多段過給式のエンジンにおいて、高圧段側（エンジンの給気通路における下流側）のターボ過給機では、低圧段側（エンジンの給気通路における上流側）のターボ過給機よりもタービンやコンプレッサの最大回転数が高いため、高圧段側のタービンおよびコンプレッサの共振回転数を高くする必要がある。 In a multistage supercharged engine as described in Patent Document 1, in a turbocharger on the high pressure side (downstream side in the engine air supply passage), on the low pressure stage side (upstream side in the engine air supply passage) Since the maximum rotational speed of the turbine and the compressor is higher than that of the turbocharger, it is necessary to increase the resonant rotational speed of the turbine and the compressor on the high-pressure stage side.
　しかしながら、電動機を設けたターボ過給機は、電動機のロータを有する分、タービンおよびコンプレッサの共振回転数が、電動機を有さないターボ過給機よりも低くなってしまう。共振回転数を最大回転数以上とするためには、電動機のロータを小さくして軽量化する必要があるが、その場合には、電動機の容量（発電量、駆動量）も小さくなる。このため、高圧段側のターボ過給機に電動機を設けても、実質的には、低圧段側のターボ過給機でＥＧＲ率の制御に必要な電動機容量の大部分を受け持つことになってしまう。つまり、高圧段側のターボ過給機に電動機を設けた場合は、その効果が十分に得られないことがあるという問題がある。 However, the turbocharger provided with the electric motor has a lower rotational speed of the turbine and the compressor than the turbocharger without the electric motor because of the rotor of the electric motor. In order to set the resonance rotational speed to be equal to or higher than the maximum rotational speed, it is necessary to make the rotor of the motor smaller and lighter, but in that case, the capacity (power generation amount and driving amount) of the motor also decreases. For this reason, even if the high-pressure stage turbocharger is provided with an electric motor, the low-pressure stage turbocharger is substantially responsible for most of the motor capacity necessary for controlling the EGR rate. End up. That is, when an electric motor is provided in the turbocharger on the high pressure stage side, there is a problem that the effect may not be obtained sufficiently.
　また、高圧段側のターボ過給機に電動機を設けた場合は、電動機が、排気直後の排気ガスにより高温となるタービンと直接接続されることになる。この場合に、電動機内の絶縁用樹脂や磁石等が熱によるダメージを受けないようにするためには、電動機に対する高い冷却能力が必要となる。このため、電動機への冷却媒体流路の断面積を大きくすることが必要になるとともに、冷却媒体を冷却するためのクーラ等の冷却装置も高い冷却能力が必須となる。従って、冷却装置等の補機が大型化して、エンジンへの搭載性が悪化するとともに、エンジン全体が大型化するという問題もある。 Also, when an electric motor is provided in the turbocharger on the high-pressure stage side, the electric motor is directly connected to a turbine that becomes hot due to exhaust gas immediately after exhaust. In this case, in order to prevent the insulating resin and magnets in the motor from being damaged by heat, a high cooling capacity for the motor is required. For this reason, it is necessary to increase the cross-sectional area of the cooling medium flow path to the electric motor, and a cooling device such as a cooler for cooling the cooling medium is also required to have a high cooling capacity. Therefore, there is a problem that the auxiliary equipment such as the cooling device is increased in size, the mountability to the engine is deteriorated, and the entire engine is increased in size.
　本発明の目的は、ターボ過給機に設けた電動機の効果を享受できるコンパクトな多段過給式のエンジンを提供することにある。 An object of the present invention is to provide a compact multistage supercharged engine that can enjoy the effect of an electric motor provided in a turbocharger.
　本発明のエンジンは、多段過給式のエンジンであって、エンジン本体の排気通路から排気ガスの一部を取り出して前記エンジン本体の給気通路に戻すＥＧＲ通路を有したＥＧＲ装置と、外気を吸入、加圧して前記エンジン本体に供給するコンプレッサおよびこのコンプレッサを駆動するタービンを有する複数のターボ過給機とを備え、前記複数のターボ過給機は、前記コンプレッサおよび前記タービンと回転駆動力を授受可能に設けられた電動機を有する少なくとも１つの第１ターボ過給機と、前記第１ターボ過給機と直列に設けられ、前記電動機を有さない少なくとも１つの第２ターボ過給機とを備えて構成され、前記複数のターボ過給機のうちの前記第２ターボ過給機の１つが、前記給気通路の前記エンジン本体に最も近い側に設けられていることを特徴とする。 An engine of the present invention is a multi-stage supercharged engine, and an EGR device having an EGR passage that extracts a part of exhaust gas from an exhaust passage of the engine body and returns it to the air supply passage of the engine body; A compressor that sucks and pressurizes and supplies the compressor to the engine body, and a plurality of turbochargers each having a turbine that drives the compressor, and the plurality of turbochargers provide rotational driving force to the compressor and the turbine. At least one first turbocharger having an electric motor provided so as to be able to exchange, and at least one second turbocharger provided in series with the first turbocharger and not having the electric motor. One of the plurality of turbochargers is provided on a side closest to the engine body of the supply passage. And wherein the are.
　本発明のエンジンにおいて、当該エンジンは、前記複数のターボ過給機として前記第１および前記第２ターボ過給機がそれぞれ１つずつ設けられた２段過給式であることが望ましい。 In the engine according to the present invention, it is preferable that the engine is a two-stage supercharging type in which each of the first and second turbochargers is provided as the plurality of turbochargers.
　本発明のエンジンにおいて、当該エンジンは、自走用の走行体、作業用の作業機、および前記作業機を搭載する旋回体のうちの少なくとも１つが、当該エンジンを駆動源として発電された電力を用いて電動モータで駆動されるハイブリッド型の建設機械のエンジンであることが望ましい。 In the engine of the present invention, at least one of the traveling body for self-running, the working machine for work, and the revolving body on which the work machine is mounted has generated electric power generated using the engine as a drive source. It is desirable that the engine is a hybrid type construction machine that is driven by an electric motor.
　本発明の多段過給式のエンジンによれば、電動機を有する第１ターボ過給機と電動機を有さない第２ターボ過給機とを含む複数のターボ過給機を備え、前記複数のターボ過給機のうちの前記第２ターボ過給機の１つが、前記給気通路の前記エンジン本体に最も近い側に設けられているため、エンジン本体に近い高圧段側のターボ過給機やその補機が大型化することを回避しつつ、エンジンの過渡応答性を向上したり、十分なＥＧＲ率を確保したりすることができる。従って、ターボ過給機に設けた電動機の効果を享受でき、かつコンパクトな多段過給式のエンジンを得ることができる。 According to the multi-stage turbocharged engine of the present invention, the turbocharger includes a plurality of turbochargers including a first turbocharger having an electric motor and a second turbocharger not having an electric motor. Since one of the second turbochargers among the superchargers is provided on the side of the air supply passage closest to the engine body, a turbocharger on the high pressure stage side close to the engine body and its While avoiding the increase in size of the auxiliary machine, it is possible to improve the transient response of the engine or to secure a sufficient EGR rate. Therefore, the effect of the electric motor provided in the turbocharger can be enjoyed, and a compact multistage supercharged engine can be obtained.
　本発明において、エンジンが、前記複数のターボ過給機として前記第１および前記第２ターボ過給機がそれぞれ１つずつ設けられた２段過給式である場合には、最小限の数のターボ過給機により多段過給式のエンジンを構成することができる。従って、最も簡易な構成で本発明のエンジンを得ることができる。 In the present invention, when the engine is a two-stage turbocharger in which each of the first and second turbochargers is provided as the plurality of turbochargers, a minimum number of turbochargers is provided. A turbocharger can constitute a multi-stage supercharged engine. Therefore, the engine of the present invention can be obtained with the simplest configuration.
　本発明のエンジンが、ハイブリッド型の建設機械のエンジンである場合には、前述した本発明の効果が、特に顕著に得られる。 When the engine of the present invention is a hybrid construction machine engine, the above-described effects of the present invention can be obtained particularly remarkably.
　すなわち、ハイブリッド型の建設機械では、走行体、作業機、および旋回体等を電気モータで駆動している分、他の油圧駆動部分の応答遅れが目立つ傾向にあるため、油圧ポンプの駆動源であるエンジンについても、従来の油圧駆動式の建設機械の場合と比べて高い応答性が要求される。しかし、建設機械の場合、乗用車や商用車などに比べてエンジンの排気量やターボ過給機のタービンの大きさが格段に大きいため、過給時のタイムラグが大きく、ハイブリッド型の建設機械に要求されるエンジンの過渡応答性に十分に応えることができなかった。
　これに対し、本発明のエンジンを利用すれば、ハイブリッド型の建設機械において必要とされる十分な過渡応答性を得ることができる。 That is, in a hybrid type construction machine, the response delay of other hydraulic drive parts tends to be conspicuous as the traveling body, work machine, and swivel body are driven by an electric motor. Some engines are also required to have higher responsiveness than conventional hydraulically driven construction machines. However, in the case of construction machinery, the engine displacement and the turbocharger turbine size are significantly larger than passenger cars and commercial vehicles, so the time lag during supercharging is large, which is required for hybrid construction machinery. The engine's transient response could not be fully met.
On the other hand, if the engine of the present invention is used, sufficient transient response required in a hybrid construction machine can be obtained.
　また、建設機械のエンジンは、乗用車や商用車に比べて、高負荷で運転する割合が非常に高く、かつエンジンの急激な加減速運転も頻繁に行われるため、ＮＯｘの発生を抑制することが難しかった。
　これに対しても、本発明のエンジンを利用すれば、高いＥＧＲ率を実現することができるので、ハイブリッド型の建設機械にも要求されるＮＯｘ発生の抑制を促進することができる。 Moreover, the engine of construction machinery has a very high ratio of driving at a high load compared to passenger cars and commercial vehicles, and the engine is frequently subjected to rapid acceleration / deceleration, so that the generation of NOx can be suppressed. was difficult.
In contrast, if the engine of the present invention is used, a high EGR rate can be realized, and therefore, it is possible to promote suppression of NOx generation that is also required for a hybrid construction machine.
本発明の一実施形態に係る建設機械のシステム構成を示すブロック図。1 is a block diagram showing a system configuration of a construction machine according to an embodiment of the present invention. 建設機械に搭載されたエンジンを示す模式図。The schematic diagram which shows the engine mounted in the construction machine. エンジンの動作フロー図。The operation | movement flowchart of an engine.
　以下、本発明の一実施形態を図面に基づいて説明する。
〔１〕パワーショベルの全体構成
　図１において、建設機械としてのパワーショベル１は、駆動源としてエンジン２を備えている。エンジン２の出力軸には、発電機モータ３および一対の油圧ポンプ４，４がそれぞれ直列に連結されており、エンジン２によって駆動される。 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[1] Overall Configuration of Power Excavator In FIG. 1, a power shovel 1 as a construction machine includes an engine 2 as a drive source. A generator motor 3 and a pair of hydraulic pumps 4, 4 are connected in series to the output shaft of the engine 2, and are driven by the engine 2.
　発電機モータ３にて発電された電力は、インバータ５を介してキャパシタ６に充電される。キャパシタ６に充電された電力は、昇圧器５Ａで昇圧されるとともに、インバータ５を介して旋回電動モータ７に出力される。旋回電動モータ７は、遊星歯車機構等を有した減速機８を介して上部旋回体９を駆動する。キャパシタ６からの電力はまた、発電機モータ３に供給される場合もあり、このような場合には、発電機モータ３を電動モータとして機能させて油圧ポンプ４を駆動し、エンジン２をアシストする。 The electric power generated by the generator motor 3 is charged to the capacitor 6 via the inverter 5. The electric power charged in the capacitor 6 is boosted by the booster 5 </ b> A and output to the swing electric motor 7 through the inverter 5. The turning electric motor 7 drives the upper turning body 9 via a speed reducer 8 having a planetary gear mechanism or the like. The electric power from the capacitor 6 may also be supplied to the generator motor 3. In such a case, the generator motor 3 is caused to function as an electric motor to drive the hydraulic pump 4 and assist the engine 2. .
　一方、油圧ポンプ４から圧送された作動油は、コントロールバルブ１０を介して作業機１１に供給される。パワーショベル１での作業機１１は、図示しないブーム、アーム、およびバケットで構成され、それぞれに設けられたブームシリンダ１２、アームシリンダ１３、およびバケットシリンダ１４に対して作動油を流出入させることで、作業機１１が油圧によって動作する。 On the other hand, the hydraulic oil pumped from the hydraulic pump 4 is supplied to the work machine 11 via the control valve 10. The work machine 11 in the excavator 1 is composed of a boom, an arm, and a bucket (not shown), and allows hydraulic oil to flow into and out of the boom cylinder 12, the arm cylinder 13, and the bucket cylinder 14 that are respectively provided. The work machine 11 is operated by hydraulic pressure.
　また、パワーショベル１の車両本体には、詳細な図示を省略するが、前述の上部旋回体９が旋回自在に設置されている他、一対のクローラ式の下部走行体が設けられている。下部走行体は、クローラに噛合するスプロケットを駆動するための走行用油圧モータ１５を有しており、これらの走行用油圧モータ１５に対しても、油圧ポンプ４からの作動油がコントロールバルブ１０を介して供給される。 The vehicle body of the excavator 1 is provided with a pair of crawler-type lower traveling bodies in addition to the above-described upper revolving body 9 being turnably installed, although the detailed illustration is omitted. The lower traveling body has a traveling hydraulic motor 15 for driving a sprocket that meshes with the crawler. The hydraulic oil from the hydraulic pump 4 also controls the control valve 10 with respect to these traveling hydraulic motors 15. Supplied through.
　従って、本実施形態のパワーショベル１は、上部旋回体９を電気エネルギで旋回駆動するとともに、作業機１１や下部走行体を油圧によって駆動するハイブリッド型の建設機械である。なお、前述した各構成は、走行用油圧モータ１５を除いて上部旋回体９に搭載され、上部旋回体９と共に旋回する。 Therefore, the power shovel 1 of the present embodiment is a hybrid construction machine that drives the upper swing body 9 to swing with electric energy and drives the work implement 11 and the lower traveling body with hydraulic pressure. Each configuration described above is mounted on the upper swing body 9 except for the traveling hydraulic motor 15, and rotates together with the upper swing body 9.
　さらに、パワーショベル１の上部旋回体９には、オペレータが操縦操作を行うキャブが設けられている。このようなキャブ内には、オペレータの座席や、エンジン２への燃料供給量を設定する燃料ダイヤル、レバー類、ペダル類、モニタ類、その他のスイッチ類などが設けられている。また、上部旋回体９には、インバータ５や後述する旋回制御装置３０が収容された制御ボックス、およびエンジン２の動作を制御するエンジンコントローラ４０が設けられている。図１には代表して、キャブ内に設置される作業機１１、操作用の作業機レバー１６、および旋回操作用の旋回レバー１７が図示されている。 Furthermore, the upper revolving structure 9 of the power shovel 1 is provided with a cab that is operated by an operator. In such a cab, there are provided an operator's seat, a fuel dial for setting a fuel supply amount to the engine 2, levers, pedals, monitors, and other switches. Further, the upper swing body 9 is provided with a control box in which the inverter 5 and a swing control device 30 to be described later are accommodated, and an engine controller 40 for controlling the operation of the engine 2. As a representative, FIG. 1 shows a working machine 11 installed in a cab, a working machine lever 16 for operation, and a turning lever 17 for turning operation.
　作業機レバー１６はＰＰＣ（Proportional Pressure Control）バルブを含んで構成され、ＰＰＣバルブにて生成されたパイロット圧によりコントロールバルブ１０の切換動作を行い、作業機１１を動作させる。
　旋回レバー１７は、その傾倒角度に応じたレバー信号を旋回制御装置３０に出力するよう、ポテンショメータ等を含んで構成されている。 The work machine lever 16 includes a PPC (Proportional Pressure Control) valve. The work machine lever 16 performs the switching operation of the control valve 10 by the pilot pressure generated by the PPC valve, and operates the work machine 11.
The turning lever 17 includes a potentiometer and the like so as to output a lever signal corresponding to the tilt angle to the turning control device 30.
　旋回制御装置３０は、上部旋回体９の旋回動作を制御するものであり、コンピュータ技術に用いられる各種のハードウェアやソフトウェアで構成される。本実施形態の旋回制御装置３０は、インバータ５に搭載されるかたちで設けられ、インバータ５に対して電気的に接続されている。 The turning control device 30 controls the turning operation of the upper turning body 9, and is composed of various hardware and software used in computer technology. The turning control device 30 of the present embodiment is provided in a form mounted on the inverter 5 and is electrically connected to the inverter 5.
　エンジンコントローラ４０は、図示しない検出手段から燃料ダイヤルの設定位置、アクセルペダルの開度、エンジン回転速度、および燃料噴射量等の検出信号を受信しており、これらの検出信号によりエンジン２の運転状態を把握し、状態に応じて燃焼室への燃料噴射量や燃料噴射タイミングなどの制御を行っている。また、エンジンコントローラ４０は、後述する電動機２５４やＥＧＲバルブ２９２（ともに図２参照）の動作も制御する。 The engine controller 40 receives detection signals such as a fuel dial set position, an accelerator pedal opening, an engine rotation speed, and a fuel injection amount from detection means (not shown), and the operation state of the engine 2 is detected by these detection signals. The amount of fuel injected into the combustion chamber and the fuel injection timing are controlled according to the state. The engine controller 40 also controls operations of an electric motor 254 and an EGR valve 292 (see FIG. 2), which will be described later.
〔２〕エンジンの構成
　以下、図２を参照して、エンジン２の構成について詳説する。
　エンジン２は、本実施形態ではディーゼルエンジンであり、内部に複数の燃焼室が形成されたエンジン本体２０と、エンジン本体２０の燃焼室に空気を供給する給気通路２１と、エンジン本体２０および給気通路２１間に設けられ給気通路２１からの空気を各燃焼室に分配する給気マニホールド２２と、エンジン本体２０から排気ガスを排出する排気通路２３と、エンジン本体２０および排気通路２３間に設けられ排気ガスを集めて排気通路２３に流入させる排気マニホールド２４と、給気通路２１に吸い込んだ外気を過給する第１ターボ過給機２５と、第１ターボ過給機２５で圧縮された空気を冷却するインタークーラ２６と、第１ターボ過給機２５からの圧縮空気をさらに圧縮する第２ターボ過給機２７と、第２ターボ過給機２７で圧縮された空気を冷却するアフタークーラ２８と、ＮＯｘの生成を抑制するためのＥＧＲ装置２９とを備えている。 [2] Configuration of Engine Hereinafter, the configuration of the engine 2 will be described in detail with reference to FIG.
The engine 2 is a diesel engine in the present embodiment, and includes an engine body 20 in which a plurality of combustion chambers are formed, an air supply passage 21 that supplies air to the combustion chambers of the engine body 20, an engine body 20, An air supply manifold 22 that is provided between the air passages 21 and distributes air from the air supply passages 21 to the combustion chambers, an exhaust passage 23 that discharges exhaust gas from the engine body 20, and between the engine body 20 and the exhaust passages 23. An exhaust manifold 24 that collects exhaust gas and flows into the exhaust passage 23, a first turbocharger 25 that supercharges the outside air sucked into the air supply passage 21, and the first turbocharger 25 compresses the exhaust gas. Compressed by an intercooler 26 that cools air, a second turbocharger 27 that further compresses compressed air from the first turbocharger 25, and a second turbocharger 27 The the aftercooler 28 for cooling air, and a EGR device 29 for suppressing the generation of NOx.
　このうちの第１ターボ過給機２５は、排気ガスの排気エネルギで回転するタービン２５１と、このタービン２５１と共に回転して外気を圧縮するコンプレッサ２５２と、タービン２５１とコンプレッサ２５２とを連結する回転軸２５３において、タービン２５１およびコンプレッサ２５２と回転駆動力を授受可能に設けられた電動機２５４とを備えている。電動機２５４は、発電機としても機能させることができ、電動機能および発電機能間の切り換えは、エンジンコントローラ４０により行われる。コンプレッサ２５２出口から第２ターボ過給機２７までは給気通路２１で連通しており、給気通路２１のコンプレッサ２５２および第２ターボ過給機２７間に、インタークーラ２６が設けられている。 Of these, the first turbocharger 25 includes a turbine 251 that rotates with exhaust energy of exhaust gas, a compressor 252 that rotates together with the turbine 251 and compresses outside air, and a rotating shaft that connects the turbine 251 and the compressor 252. 253 includes a turbine 251 and a compressor 252 and an electric motor 254 provided so as to be able to transmit and receive a rotational driving force. The electric motor 254 can also function as a generator, and switching between the electric function and the power generation function is performed by the engine controller 40. The air supply passage 21 communicates from the compressor 252 outlet to the second turbocharger 27, and an intercooler 26 is provided between the compressor 252 and the second turbocharger 27 in the air supply passage 21.
　第２ターボ過給機２７は、第１ターボ過給機２５よりもエンジン本体２０に近い高圧段側に設けられている。この第２ターボ過給機２７は、第１ターボ過給機２５とは異なって電動機を有さないターボ過給機であり、互いに回転軸２７３によって直結されたタービン２７１およびコンプレッサ２７２を備えている。コンプレッサ２７２出口から給気マニホールド２２までは給気通路２１で連通しており、給気通路２１のコンプレッサ２７２および給気マニホールド２２間に、アフタークーラ２８が設けられている。 The second turbocharger 27 is provided on the high-pressure stage side closer to the engine body 20 than the first turbocharger 25. Unlike the first turbocharger 25, the second turbocharger 27 is a turbocharger that does not have an electric motor, and includes a turbine 271 and a compressor 272 that are directly connected to each other by a rotating shaft 273. . The outlet of the compressor 272 and the supply manifold 22 communicate with each other through the supply passage 21, and an after cooler 28 is provided between the compressor 272 and the supply manifold 22 in the supply passage 21.
　ＥＧＲ装置２９は、排気通路２３から分岐して給気通路２１の下流側（アフタークーラ２８よりも下流側）に連通するＥＧＲ通路２９１を備えている。このＥＧＲ通路２９１には、当該ＥＧＲ通路２９１を開閉するＥＧＲバルブ２９２と、排気マニホールド２４からの排気ガスを冷却するＥＧＲクーラ２９３とが設けられている。このＥＧＲ装置２９において、排気ガス圧力が給気圧力よりも高い場合に、ＥＧＲバルブ２９２を開くことで、排気ガスの一部を給気側に戻すことが可能である。ＥＧＲバルブ２９２の開閉制御は、排気通路２３または排気マニホールド２４に設けられた図示しないＮＯｘ量検出手段からの検出信号に基づき、エンジンコントローラ４０によって行われる。 The EGR device 29 includes an EGR passage 291 that branches from the exhaust passage 23 and communicates with the downstream side of the air supply passage 21 (downstream side after the aftercooler 28). The EGR passage 291 is provided with an EGR valve 292 that opens and closes the EGR passage 291 and an EGR cooler 293 that cools the exhaust gas from the exhaust manifold 24. In the EGR device 29, when the exhaust gas pressure is higher than the supply air pressure, it is possible to return a part of the exhaust gas to the supply air side by opening the EGR valve 292. The opening / closing control of the EGR valve 292 is performed by the engine controller 40 based on a detection signal from a NOx amount detection means (not shown) provided in the exhaust passage 23 or the exhaust manifold 24.
〔３〕エンジンの作用
　次に、エンジン２の動作フローを示す図３を参照しつつ、エンジン２の作用について説明する。 [3] Action of Engine Next, the action of the engine 2 will be described with reference to FIG.
　図３において、先ず、エンジン２の給気通路２１に外気が流入し（Ｓ１）、低圧段側の第１ターボ過給機２５のコンプレッサ２５２で圧縮される（Ｓ２）。圧縮された空気は、インタークーラ２６で冷却された後（Ｓ３）、高圧段側の第２ターボ過給機２７のコンプレッサ２７２でさらに圧縮される（Ｓ４）。第２ターボ過給機２７で圧縮された空気は、アフタークーラ２８で冷却された後（Ｓ５）、ＥＧＲ装置２９によって排気通路２３から戻された排気ガスと混合される（Ｓ６）。圧縮空気と排気ガスとの混合気は、給気マニホールド２２を経由してエンジン本体２０へ給気される（Ｓ７）。これにより、エンジン本体２０に供給される空気量が増加してエンジン２の出力が向上するとともに、ＮＯｘの発生が抑制され、燃費も向上する。 3, first, outside air flows into the air supply passage 21 of the engine 2 (S1), and is compressed by the compressor 252 of the first turbocharger 25 on the low pressure stage side (S2). The compressed air is cooled by the intercooler 26 (S3), and further compressed by the compressor 272 of the second turbocharger 27 on the high pressure stage side (S4). The air compressed by the second turbocharger 27 is cooled by the aftercooler 28 (S5) and then mixed with the exhaust gas returned from the exhaust passage 23 by the EGR device 29 (S6). The mixture of compressed air and exhaust gas is supplied to the engine body 20 via the supply manifold 22 (S7). As a result, the amount of air supplied to the engine body 20 is increased, the output of the engine 2 is improved, the generation of NOx is suppressed, and the fuel consumption is also improved.
　エンジン本体２０では内燃によって排気ガスが発生し（Ｓ８）、発生した排気ガスは、排気マニホールド２４を通った後、第２ターボ過給機２７のタービン２７１とＥＧＲ通路２９１とに向けて分配される（Ｓ９）。ＥＧＲ通路２９１へ分配された排気ガスは、ＥＧＲクーラ２９３で冷却された後（Ｓ１０）、第２ターボ過給機２７からの圧縮空気と混合される（Ｓ６）。 In the engine body 20, exhaust gas is generated by internal combustion (S 8), and the generated exhaust gas passes through the exhaust manifold 24 and is distributed toward the turbine 271 and the EGR passage 291 of the second turbocharger 27. (S9). The exhaust gas distributed to the EGR passage 291 is cooled by the EGR cooler 293 (S10) and then mixed with the compressed air from the second turbocharger 27 (S6).
　一方、第２ターボ過給機２７のタービン２７１へ分配された排気ガスは、高圧段側のタービン２７１を駆動する（Ｓ１１）。タービン２７１の駆動力は、コンプレッサ２７２に伝達され、前述のように第１ターボ過給機２５からの圧縮空気をさらに圧縮する（Ｓ４）。
　第２ターボ過給機２７のタービン２７１を駆動した排気ガスは、第１ターボ過給機２５で低圧段側のタービン２５１を駆動し（Ｓ１２）、排気通路２３から排出される（Ｓ１３）。この際のタービン２５１の駆動力は、電動機２５４に伝達されて、電動機２５４を駆動する。 On the other hand, the exhaust gas distributed to the turbine 271 of the second turbocharger 27 drives the turbine 271 on the high-pressure stage side (S11). The driving force of the turbine 271 is transmitted to the compressor 272 and further compresses the compressed air from the first turbocharger 25 as described above (S4).
The exhaust gas that has driven the turbine 271 of the second turbocharger 27 drives the low-pressure stage turbine 251 by the first turbocharger 25 (S12), and is discharged from the exhaust passage 23 (S13). The driving force of the turbine 251 at this time is transmitted to the electric motor 254 to drive the electric motor 254.
　ここで、エンジンコントローラ４０は、図示しない燃料ダイヤルの設定位置やアクセルペダルの開度等の情報に基づき、エンジン２が加速運転状態にあると判定すると、電動機２５４を電動機として機能させ、エンジン２が加速運転状態にないと判定すると、電動機２５４を発電機として機能させる。その結果、電動機２５４が発電機として機能する場合は、タービン２５１の駆動力により発電が行われて（Ｓ１４）、電力が発生する（Ｓ１５）。また、電動機として機能する場合は、電動機２５４が駆動力を出力してコンプレッサ２５２の駆動をアシストし（Ｓ１５）、タービン２５１とともにコンプレッサ２５２を駆動して、コンプレッサ２５２に外気を圧縮させる（Ｓ２）。 Here, when the engine controller 40 determines that the engine 2 is in an acceleration operation state based on information such as a fuel dial setting position and an accelerator pedal opening (not shown), the engine controller 254 causes the motor 254 to function as an electric motor. If it determines with it not being in an acceleration driving | running state, the electric motor 254 will function as a generator. As a result, when the electric motor 254 functions as a generator, electric power is generated by the driving force of the turbine 251 (S14), and electric power is generated (S15). When functioning as an electric motor, the electric motor 254 outputs a driving force to assist the driving of the compressor 252 (S15), drives the compressor 252 together with the turbine 251, and compresses the outside air to the compressor 252 (S2).
　以上のような第１ターボ過給機２５および第２ターボ過給機２７の作用により、排気ガス圧力、給気圧力、およびＥＧＲ率は、第１ターボ過給機２５の電動機２５４の発電または駆動に応じて、以下の表１に示すように変化する。 Due to the action of the first turbocharger 25 and the second turbocharger 27 as described above, the exhaust gas pressure, the supply pressure, and the EGR rate are generated or driven by the electric motor 254 of the first turbocharger 25. Depending on the above, it changes as shown in Table 1 below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　すなわち、第１ターボ過給機２５の電動機２５４を発電機として機能させると、低圧段側のタービン２５１の回転抵抗が大きくなるため、タービン２５１入口の排気ガス圧力が高くなり、高圧段側のタービン２７１出口や排気マニホールド２４の排気ガス圧力も高くなる。
　一方、電動機２５４の回転抵抗によりタービン２５１の回転数が低下するため、低圧段側のコンプレッサ２５２出口の給気圧力は低くなり、高圧段側のコンプレッサ２７２出口および給気マニホールド２２の給気圧力も低くなる。 That is, when the electric motor 254 of the first turbocharger 25 is caused to function as a generator, the rotational resistance of the turbine 251 on the low pressure stage side increases, so the exhaust gas pressure at the inlet of the turbine 251 increases and the turbine on the high pressure stage side increases. The exhaust gas pressure at the outlet 271 and the exhaust manifold 24 also increases.
On the other hand, since the rotational speed of the turbine 251 is reduced by the rotational resistance of the electric motor 254, the supply air pressure at the outlet of the compressor 252 on the low pressure stage side becomes low, and the supply pressure of the compressor 272 outlet on the high pressure stage side and the supply manifold 22 also Lower.
　このように、第１ターボ過給機２５の電動機２５４を発電機として機能させることにより、排気マニホールド２４の排気ガス圧力を給気マニホールド２２の給気圧力よりも大幅に高くすることができる。その分、ＥＧＲクーラ２９３を通って給気マニホールド２２に流れる排気ガス量が増加するため、ＥＧＲ率を増加させることができる。 Thus, by causing the electric motor 254 of the first turbocharger 25 to function as a generator, the exhaust gas pressure of the exhaust manifold 24 can be made significantly higher than the supply pressure of the supply manifold 22. Accordingly, the amount of exhaust gas flowing through the EGR cooler 293 to the air supply manifold 22 increases, so that the EGR rate can be increased.
　反対に、第１ターボ過給機２５の電動機２５４を電動機として機能させてタービン２５１を駆動させると、排気ガス圧力が低下し、かつ給気圧力が増加するため、ＥＧＲ率は減少する。このように、電動機２５４の発電量または駆動量に応じて、ＥＧＲ率の制御が可能となる。 Conversely, when the motor 254 of the first turbocharger 25 is caused to function as an electric motor and the turbine 251 is driven, the exhaust gas pressure decreases and the supply air pressure increases, so the EGR rate decreases. In this way, the EGR rate can be controlled according to the amount of power generation or driving amount of the electric motor 254.
　また、エンジン２の加速運転時に第１ターボ過給機２５の電動機２５４を電動機として機能させて、コンプレッサ２５２の回転をアシストすれば、アシストがない場合に比べて、過給圧力が早く立ち上がることになる。従って、エンジン２の過渡応答性を向上できる。 Further, if the motor 254 of the first turbocharger 25 is made to function as an electric motor during the acceleration operation of the engine 2 to assist the rotation of the compressor 252, the supercharging pressure will rise faster than when there is no assist. Become. Therefore, the transient response of the engine 2 can be improved.
　さらに、第１ターボ過給機２５の電動機２５４で発電した電力を、バッテリやキャパシタ等を含む電力供給系に戻すことにより、燃費の向上が可能となる。すなわち、本実施形態のパワーショベル１の場合、エンジン２の出力軸に結合した発電機モータ３を第１ターボ過給機２５で発電した電力により駆動して、エンジン２の駆動をアシストすることにより、燃費の向上が可能である。反対に、発電機モータ３で発電した電力を利用して第１ターボ過給機２５の電動機２５４を駆動することで、コンプレッサ２５２の回転をアシストすることもできる。 Furthermore, the fuel consumption can be improved by returning the electric power generated by the electric motor 254 of the first turbocharger 25 to the electric power supply system including a battery, a capacitor, and the like. That is, in the case of the power shovel 1 of the present embodiment, the generator motor 3 coupled to the output shaft of the engine 2 is driven by the electric power generated by the first turbocharger 25 to assist the drive of the engine 2. , Fuel economy can be improved. On the contrary, the rotation of the compressor 252 can be assisted by driving the electric motor 254 of the first turbocharger 25 using the electric power generated by the generator motor 3.
　このように、低圧段側の第１ターボ過給機２５に電動機２５４を設けることにより、前述した様々な効果が得られる。ここで、第１ターボ過給機２５では、電動機２５４を設けた分だけ共振回転数が低下することになるが、低圧段側に設けられている第１ターボ過給では、そもそもタービン２７１およびコンプレッサ２７２の最大回転数が低いため、電動機２５４を設けた場合であっても、最大回転数が共振回転数を上回ることがない。 Thus, by providing the electric motor 254 in the first turbocharger 25 on the low pressure stage side, the various effects described above can be obtained. Here, in the first turbocharger 25, the resonance rotational speed is reduced by the amount provided by the electric motor 254. However, in the first turbocharger provided on the low pressure stage side, the turbine 271 and the compressor are originally provided. Since the maximum rotational speed of 272 is low, the maximum rotational speed does not exceed the resonant rotational speed even when the electric motor 254 is provided.
　しかも、高圧段側の第２ターボ過給機２７は、電動機を有しておらず共振回転数の高いターボ過給機であるため、タービンおよびコンプレッサを高回転で駆動させることができ、排気ガス圧力や給気圧力を十分に高くすることができる。このため、高いＥＧＲ率が確保できるとともに、過給によるエンジン出力の向上も実現できる。また、第２ターボ過給機２７が電動機を有していないため、第２ターボ過給機２７に関する冷却設備等の補機も、大型化することなく従来のものを使用できる。 Moreover, since the second turbocharger 27 on the high-pressure stage side is a turbocharger that does not have an electric motor and has a high resonance speed, the turbine and the compressor can be driven at a high speed, and the exhaust gas The pressure and the supply air pressure can be sufficiently increased. For this reason, a high EGR rate can be ensured, and engine output can be improved by supercharging. In addition, since the second turbocharger 27 does not have an electric motor, auxiliary equipment such as cooling equipment related to the second turbocharger 27 can be used without increasing its size.
　以上の本実施形態によれば、ＥＧＲ装置２９を備えた多段過給式のエンジン２において、エンジン本体２０に最も近い高圧段側には電動機を有さない第２ターボ過給機２７が設けられ、エンジン本体２０から離れた低圧段側には電動機２５４を備えた第１ターボ過給機２５が設けられているので、ターボ過給機への電動機の採用に伴ってエンジン２が大型化したり、コストが上昇したりすることなく、ターボ過給機に設けた電動機による前述した効果を享受することができる。 According to the present embodiment described above, in the multistage supercharged engine 2 provided with the EGR device 29, the second turbocharger 27 that does not have an electric motor is provided on the high-pressure stage side closest to the engine body 20. Since the first turbocharger 25 provided with the electric motor 254 is provided on the low pressure stage side away from the engine body 20, the engine 2 becomes larger with the adoption of the electric motor for the turbocharger, The above-described effects of the electric motor provided in the turbocharger can be enjoyed without increasing the cost.
　なお、本発明は前述の実施形態に限定されるものではなく、本発明の目的を達成できる範囲での変形、改良等は本発明に含まれるものである。
　例えば、前記実施形態において、エンジン２は、ディーゼルエンジンであったが、ガソリンエンジン等の他のエンジンであってもよい。 It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the embodiment, the engine 2 is a diesel engine, but may be another engine such as a gasoline engine.
　前記実施形態において、エンジン２は、第１ターボ過給機２５および第２ターボ過給機２７による２段過給方式を採用していたが、エンジン本体２０に最も近い側の過給機が発電機を有さないターボ過給機であれば、エンジン２において３つ以上の過給機を設けてもよい。３つ以上の過給機を直列に設ければ、エンジン２の過給圧をより高めることができるので、ＥＧＲ率をさらに向上させることができる。 In the above-described embodiment, the engine 2 employs the two-stage supercharging system using the first turbocharger 25 and the second turbocharger 27, but the supercharger closest to the engine body 20 generates power. If the turbocharger does not have a machine, the engine 2 may be provided with three or more turbochargers. If three or more superchargers are provided in series, the supercharging pressure of the engine 2 can be further increased, so that the EGR rate can be further improved.
　前記実施形態において、電動機２５４は、第１ターボ過給機２５のタービン２５１およびコンプレッサ２５２間の回転軸２５３に設けられていたがこれに限られない。電動機２５４は、タービン２５１およびコンプレッサ２５２と回転駆動力を授受可能に設けられていればよく、例えば、第１ターボ過給機２５に歯車等の動力伝達機構を用いてタービン２５１およびコンプレッサ２５２と回転駆動力を授受可能に構成してもよい。 In the above embodiment, the electric motor 254 is provided on the rotary shaft 253 between the turbine 251 and the compressor 252 of the first turbocharger 25, but is not limited thereto. The electric motor 254 only needs to be provided so as to be able to exchange rotational driving force with the turbine 251 and the compressor 252. For example, the first turbocharger 25 rotates with the turbine 251 and the compressor 252 using a power transmission mechanism such as a gear. The driving force may be exchanged.
　前記実施形態では、パワーショベル１において、上部旋回体９を電気エネルギで旋回駆動し、作業機１１や下部走行体を油圧によって駆動していたがこれに限られない。すなわち、走行体、作業機、および旋回体等を電気エネルギおよび油圧で駆動するハイブリッド型のものであれば、どの被駆動体の駆動に電気エネルギおよび油圧を割り当てるかは任意である。 In the above-described embodiment, in the power shovel 1, the upper swing body 9 is driven to swing with electric energy, and the work implement 11 and the lower traveling body are driven with hydraulic pressure, but the present invention is not limited thereto. That is, as long as it is a hybrid type that drives the traveling body, the work machine, the turning body, and the like with electric energy and hydraulic pressure, it is arbitrary which electric power and hydraulic pressure are allocated to drive of the driven body.
　ハイブリッド型の建設機械としてはパワーショベル１に限られず、ホイルローダやダンプトラック等の他の建設機械であってもよい。例えば、ホイルローダの場合は、作業機を油圧で駆動し、走行体を電気エネルギで駆動すればよく、ダンプトラックの場合は、ベッセルを作業機として油圧で駆動し、走行体を電気エネルギで駆動すればよい。当然のことながら、これとは反対に、作業機を電気エネルギで駆動し、走行体を油圧で駆動してもよい。 The hybrid construction machine is not limited to the power shovel 1, and may be another construction machine such as a wheel loader or a dump truck. For example, in the case of a wheel loader, the working machine may be driven by hydraulic pressure and the traveling body may be driven by electric energy. In the case of a dump truck, the vessel is driven by hydraulic pressure and the traveling body may be driven by electric energy. That's fine. As a matter of course, on the contrary, the working machine may be driven by electric energy and the traveling body may be driven hydraulically.
　本発明は、パワーショベル等の建設機械に利用できる他、上部旋回体を有したクレーン等の作業機械にも利用することができる。 The present invention can be used not only for construction machines such as power shovels but also for work machines such as cranes having an upper rotating body.
　１…ハイブリッド型の建設機械であるパワーショベル、２…エンジン、２０…エンジン本体、２１…給気通路、２３…排気通路、２５…第１ターボ過給機、２７…第２ターボ過給機、２９…ＥＧＲ装置、４０…エンジンコントローラ、２５１，２７１…タービン、２５２，２７２…コンプレッサ、２５４…電動機、２９１…ＥＧＲ通路。 DESCRIPTION OF SYMBOLS 1 ... Power excavator which is a hybrid type construction machine, 2 ... Engine, 20 ... Engine main body, 21 ... Air supply passage, 23 ... Exhaust passage, 25 ... 1st turbocharger, 27 ... 2nd turbocharger, 29 ... EGR device, 40 ... engine controller, 251,271 ... turbine, 252,272 ... compressor, 254 ... electric motor, 291 ... EGR passage.

Claims (3)

  1. 　多段過給式のエンジンであって、
    　エンジン本体の排気通路から排気ガスの一部を取り出して前記エンジン本体の給気通路に戻すＥＧＲ通路を有したＥＧＲ装置と、
    　外気を吸入、加圧して前記エンジン本体に供給するコンプレッサおよびこのコンプレッサを駆動するタービンを有する複数のターボ過給機とを備え、
    　前記複数のターボ過給機は、
    　前記コンプレッサおよび前記タービンと回転駆動力を授受可能に設けられた電動機を有する少なくとも１つの第１ターボ過給機と、
    　前記第１ターボ過給機と直列に設けられ、前記電動機を有さない少なくとも１つの第２ターボ過給機とを備えて構成され、
    　前記複数のターボ過給機のうちの前記第２ターボ過給機の１つが、前記給気通路の前記エンジン本体に最も近い側に設けられている
    　ことを特徴とするエンジン。     A multi-stage supercharged engine,
    An EGR device having an EGR passage for taking out a part of the exhaust gas from the exhaust passage of the engine body and returning it to the supply passage of the engine body;
    A compressor that sucks and pressurizes outside air and supplies the compressed air to the engine body, and a plurality of turbochargers having a turbine that drives the compressor,
    The plurality of turbochargers are:
    At least one first turbocharger having an electric motor provided so as to be able to exchange rotational driving force with the compressor and the turbine;
    The first turbocharger is provided in series, and includes at least one second turbocharger that does not have the electric motor.
    One of the plurality of turbochargers, wherein one of the second turbochargers is provided on a side of the supply passage that is closest to the engine body.
  2. 　請求項１に記載のエンジンにおいて、
    　当該エンジンは、前記複数のターボ過給機として前記第１および前記第２ターボ過給機がそれぞれ１つずつ設けられた２段過給式である
    　ことを特徴とするエンジン。     The engine according to claim 1,
    The engine is a two-stage supercharging type in which each of the first and second turbochargers is provided as each of the plurality of turbochargers.
  3. 　請求項１または請求項２に記載のエンジンにおいて、
    　当該エンジンは、自走用の走行体、作業用の作業機、および前記作業機を搭載する旋回体のうちの少なくとも１つが、当該エンジンを駆動源として発電された電力を用いて電動モータで駆動されるハイブリッド型の建設機械のエンジンである
    　ことを特徴とするエンジン。     The engine according to claim 1 or 2,
    The engine is driven by an electric motor using at least one of a self-propelled traveling body, a working working machine, and a revolving body equipped with the working machine using electric power generated by using the engine as a driving source. An engine characterized by being an engine of a hybrid type construction machine.
PCT/JP2011/050683 2010-02-09 2011-01-18 Engine WO2011099326A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014211127A1 (en) * 2014-06-11 2015-12-17 Ford Global Technologies, Llc Supercharged internal combustion engine with exhaust gas turbochargers arranged in series and exhaust gas recirculation and method for operating such an internal combustion engine

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5552983B2 (en) * 2010-09-16 2014-07-16 いすゞ自動車株式会社 Electric turbo system
US9777619B2 (en) 2012-01-20 2017-10-03 Yanmar Co., Ltd. Ship engine
JP5963496B2 (en) 2012-03-28 2016-08-03 ヤンマー株式会社 engine
US9903323B2 (en) 2015-03-10 2018-02-27 Denso International America, Inc. Emissions reduction system for an internal combustion engine
US9745927B2 (en) * 2015-03-10 2017-08-29 Denso International America, Inc. Emissions reduction system for an internal combustion engine
JP6114446B1 (en) * 2016-07-14 2017-04-12 矢野　隆志 Low-pressure stage drive hierarchical electric turbocharger device and power system equipped with the low-pressure stage drive hierarchical electric turbocharger device

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0230924A (en) * 1988-07-18 1990-02-01 Isuzu Ceramics Kenkyusho:Kk Turbocharger control unit
JP2002038962A (en) * 2000-07-24 2002-02-06 Hitachi Ltd Controller for internal combustion engine with turbocharger
JP2004076687A (en) * 2002-08-21 2004-03-11 Toyota Motor Corp Exhaust/electric supercharging type hybrid vehicle
JP2005009315A (en) * 2003-06-16 2005-01-13 Nissan Diesel Motor Co Ltd Two-stage supercharger for engine
JP2005248860A (en) * 2004-03-04 2005-09-15 Toyota Motor Corp Control device for supercharger with motor
JP2007239566A (en) * 2006-03-08 2007-09-20 Hino Motors Ltd Auxiliary device of supercharger using waste heat energy of egr gas
JP2008075549A (en) * 2006-09-21 2008-04-03 Hitachi Ltd Control device for internal combustion engine

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0230924A (en) * 1988-07-18 1990-02-01 Isuzu Ceramics Kenkyusho:Kk Turbocharger control unit
JP2002038962A (en) * 2000-07-24 2002-02-06 Hitachi Ltd Controller for internal combustion engine with turbocharger
JP2004076687A (en) * 2002-08-21 2004-03-11 Toyota Motor Corp Exhaust/electric supercharging type hybrid vehicle
JP2005009315A (en) * 2003-06-16 2005-01-13 Nissan Diesel Motor Co Ltd Two-stage supercharger for engine
JP2005248860A (en) * 2004-03-04 2005-09-15 Toyota Motor Corp Control device for supercharger with motor
JP2007239566A (en) * 2006-03-08 2007-09-20 Hino Motors Ltd Auxiliary device of supercharger using waste heat energy of egr gas
JP2008075549A (en) * 2006-09-21 2008-04-03 Hitachi Ltd Control device for internal combustion engine

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014211127A1 (en) * 2014-06-11 2015-12-17 Ford Global Technologies, Llc Supercharged internal combustion engine with exhaust gas turbochargers arranged in series and exhaust gas recirculation and method for operating such an internal combustion engine
DE102014211127B4 (en) 2014-06-11 2022-10-06 Ford Global Technologies, Llc Supercharged internal combustion engine with exhaust gas turbochargers arranged in series and exhaust gas recirculation and method for operating such an internal combustion engine

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