JP2009041386A - Engine supercharging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine supercharging device in which the motor section and the control section of an electric supercharger are sufficiently cooled by a simple structure. <P>SOLUTION: An engine CE comprises the electric supercharger 14, an EGR passage 27, a water-cooling EGR cooler 28, and a cooling water passage 45 for supplying cooling water to the EGR cooler 28. The electric supercharger 14 comprises a compressor section 33, the motor section 34 in which a voltage control section is incorporated, and a cooling water jacket 36. The cooling water passage 45 supplies the cooling water supplied by a water pump 41 to the cooling water jacket 36 of the electric supercharger 14 to sufficiently cool the motor section 34 and the voltage control section. Then, the cooling water passage 45 supplies the cooling water to the EGR cooler 28 to cool EGR gas. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an engine supercharger in which an electric supercharger is cooled by cooling water of a water-cooled EGR cooler that cools high-temperature EGR gas that recirculates from an exhaust system to an intake system.

  An electric supercharger for an engine using an electric motor (motor) that uses electric power supplied from a power source such as an alternator or a battery as a power source is widely known (for example, see Patent Document 1). There is also known an exhaust turbocharger in which a turbine is auxiliary driven by an electric motor (see, for example, Patent Document 2). And, unlike a turbocharger or an exhaust turbocharger that does not use an electric motor, an electric supercharger can perform supercharging with a good response regardless of the engine speed. Therefore, there is an advantage that the output torque can be effectively increased. For this reason, by providing the electric supercharger, for example, it is possible to downsize the engine or its displacement while ensuring the output torque in the low rotation region, and thus the fuel efficiency can be improved.

The electric supercharger is usually disposed in the engine room, and a rotary compressor unit that pressurizes intake air flowing in the intake passage, a motor unit that rotationally drives the compressor unit, and an operation of the motor unit And a control unit for controlling.
JP-T-2004-505201 (paragraph [0011], FIG. 1) JP 2006-002568 A (paragraph [0018], FIG. 1)

  By the way, a considerable amount of heat is generated in the compressor unit, motor unit, or control unit that constitutes the electric supercharger, but the electrical component or electronic component mounted on the motor unit or control unit is relatively weak against heat. It is necessary to quickly release the generated heat to the outside and cool the motor unit and the control unit. However, since the inside of the engine room is considerably heated due to heat released from the engine, there is a problem that it is difficult to sufficiently cool the motor unit and the control unit in the conventional electric supercharger. Then, although the response | compatibility of cooling a motor part and a control part with cooling water is also considered, in this case, since the supply mechanism of the cooling water to an electric supercharger must be provided, the structure of an engine or an electric supercharger is There is a problem of increasing complexity.

  The present invention has been made to solve the above-described conventional problems, and provides an engine supercharging device capable of sufficiently cooling a motor unit and a control unit of an electric supercharger with a simple structure. It is a problem to be solved.

  An engine supercharging device according to the present invention made to solve the above problems includes an electric supercharger, an EGR passage that recirculates a part of exhaust gas to an intake system, and a water-cooled type disposed in the EGR passage. The EGR cooler and a cooling water passage for supplying cooling water to the EGR cooler are provided. The electric supercharger includes a compressor unit, a motor unit that drives the compressor unit, and a booster circuit unit that boosts the power supplied from the power source to the motor unit. Here, the cooling water passage supplies the cooling water to the electric supercharger cooling unit (cooling water jacket) that cools at least one of the motor unit and the booster circuit unit of the electric supercharger, and then the EGR cooler. To supply.

  In the engine supercharging device according to the present invention, when an (cooled) EGR cooler intercooler that cools the cooling water flowing out from the EGR cooler is provided, the cooling water passage serves as the EGR cooler. Is supplied to the electric supercharger cooling unit that cools at least one of the motor unit and the booster circuit unit of the electric supercharger via the intercooler for EGR cooler. Good.

  In the engine supercharging device according to the present invention, the EGR passage connects the intake passage and the exhaust passage on one end side of the engine in the cylinder arrangement direction of the engine (hereinafter referred to as “engine longitudinal direction”). The cooling water intake portion of the cooling water passage is provided on the other end side of the engine as viewed in the engine longitudinal direction, and the electric supercharger is in a direction perpendicular to the cylinder arrangement direction of the engine (hereinafter referred to as “engine width direction”). It is preferable that the cooling water passage is disposed on the side where the cooling water passage connecting the cooling water intake portion of the cooling water passage and the cooling water introduction portion of the EGR cooler is disposed. That is, it is preferable that the cooling water passage and the electric supercharger are disposed on the same side in the engine width direction.

  When an exhaust turbocharger is provided for the engine (that is, when supercharging is assisted by the electric turbocharger based on the exhaust turbocharger), the compressor unit of the electric supercharger Is disposed in the intake passage upstream of the compressor of the exhaust turbocharger, and the cooling water intake portion of the cooling water passage is preferably disposed on the side where the exhaust passage is located in the engine width direction.

  According to the engine supercharging device of the present invention, the cooling water is supplied to the electric supercharger cooling unit that cools the motor unit and / or the booster circuit unit by utilizing or sharing a part of the cooling water passage for the EGR cooler. Can be supplied. For this reason, cooling of a motor part and / or a pressure | voltage rise circuit part can be performed effectively, simplifying the structure of a cooling water channel | path and by extension, the structure of an engine and a supercharging device as much as possible. In addition, since the temperature of the cooling water for the EGR cooler is significantly increased by heat exchange in the EGR cooler, the cooling effect is low even if the cooling water after flowing through the EGR cooler is supplied to the electric supercharger cooling unit. . However, in the supercharging device for an engine according to the present invention, since cooling water is supplied to the electric supercharger cooling unit before introduction into the EGR cooler, the cooling effect by heat exchange of the motor unit and / or the booster circuit unit Can be greatly increased.

  If an EGR cooler intercooler is provided, cooling water may be supplied to the electric supercharger cooling section via the EGR cooler intercooler after being supplied to the EGR cooler. While simplifying the structure of the water passage and the structure of the engine and the supercharging device as much as possible, the motor section and / or the booster circuit section can be cooled effectively.

  In the engine supercharging device according to the present invention, when the cooling water passage and the electric supercharger are disposed on the same side (for example, the exhaust passage side or the exhaust manifold side) in the engine width direction, The structure of the passage can be further simplified.

  Further, the compressor portion of the electric supercharger is disposed in the intake passage upstream from the compressor of the exhaust turbocharger, and the cooling water intake portion of the cooling water passage is disposed on the side where the exhaust passage is located in the engine width direction. In this case, the cooling water passage can be simplified while enhancing the assist performance for supercharging by the exhaust turbocharger.

  Embodiments 1 to 3 of the present invention will be specifically described below with reference to the accompanying drawings. The first embodiment relates to a supercharger for a spark ignition engine that is not provided with an intercooler for EGR cooler, and the second embodiment is an overcharge of a spark ignition engine that is provided with an intercooler for EGR cooler. The third embodiment relates to a turbocharger for a diesel engine that is not provided with an intercooler for EGR cooler. In the drawings according to the first to third embodiments, components having the same structure or function or corresponding elements are denoted by the same reference numerals.

(Embodiment 1)
Embodiment 1 of the present invention will be described below. First, a system configuration of a spark ignition type engine (for example, a gasoline engine) including the supercharging device according to the first embodiment and an accessory device thereof will be described.
As shown in FIG. 1, in each cylinder (only one cylinder is shown) of a spark ignition type multi-cylinder engine CE that uses gasoline or the like as fuel, when the intake valve 1 is opened, the combustion chamber opens from the intake port 2. The air-fuel mixture is sucked into 3. The air-fuel mixture in the combustion chamber 3 is compressed by the piston 4 and is ignited and burned by the spark plug 5 at a predetermined timing. Gas generated by combustion, that is, exhaust gas, is discharged to the exhaust port 7 when the exhaust valve 6 is opened.

  These series of operations are repeated, and the piston 4 repeats reciprocating motion in the cylinder 8. The reciprocating motion of the piston 4 is converted into a rotational motion (torque) of the crankshaft 10 by a link mechanism including a connecting rod (connecting rod) 9 and the like. This rotational movement of the crankshaft 10 is taken out as engine output and drives the vehicle and also drives auxiliary equipment such as an alternator and an air conditioner. The engine CE is driven (cranked) by the engine starter 11 at the start-up until a complete explosion occurs.

  An intake system (intake system) that supplies fuel combustion air (intake air) to the combustion chamber 3 of each cylinder of the engine CE is provided with a single common intake passage 12 that is common to all cylinders. The front end (upstream end) of the common intake passage 12 is open to the atmosphere, and an air cleaner 13 for removing dust and the like in the intake air is provided near the front end (see FIG. 3).

  The common intake passage 12 has an electric supercharger 14, a compressor 15a (pump) of an exhaust turbocharger 15, and an air-cooled intercooler 16 in order from the upstream side in the flow direction of the intake air. Is provided. Here, the electric supercharger 14 and the exhaust turbocharger 15 pressurize the intake air to supercharge the engine CE. The intercooler 16 cools the intake air whose temperature has increased due to pressurization (adiabatic compression). Note that an air flow sensor 17 (see FIG. 3) for detecting the intake air amount is provided in the common intake passage 12 on the upstream side of the electric supercharger 14.

  Further, on the downstream side of the intercooler 16, the common intake passage 12 is provided with a throttle valve 18 that restricts the flow of intake air in the common intake passage 12 in accordance with the amount of depression of an accelerator pedal (not shown). . The throttle valve 18 is a so-called electric throttle valve that is driven to open and close by a drive motor (not shown) according to the accelerator opening. The downstream end of the common intake passage 12 is connected to a surge tank 19 that attenuates the pulsation of the intake air and stabilizes its flow.

  The surge tank 19 is connected to an independent intake passage 20 for supplying intake air individually to the combustion chamber 3 of each cylinder, and its downstream end is connected to the intake port 2 of the corresponding cylinder. Each independent intake passage 20 has a fuel injection valve 21 for injecting fuel (for example, gasoline) into the independent intake passage 20 or the intake port 2 to generate an air-fuel mixture. It is arrange | positioned so that it may face. The engine CE is a port injection engine that injects fuel into the independent intake passage 20 or the intake port 2, but a direct injection engine that directly injects fuel into the combustion chamber 3 may be used. Further, instead of the exhaust turbocharger 15, an optional supercharger other than the electric supercharger, for example, a mechanical supercharger (supercharger) may be provided. Even if the exhaust turbocharger 15 or a supercharger that replaces the exhaust turbocharger 15 is not provided, it is within the scope of the present invention if the electric supercharger 14 is provided.

  Further, the engine CE is provided with an exhaust system (exhaust system) that exhausts exhaust gas discharged from each combustion chamber 3 into the atmosphere, and this exhaust system has a single common exhaust passage common to each cylinder. 23 is provided. However, when viewed in the flow direction of the exhaust gas, the upstream end vicinity portion (exhaust manifold) branches for each cylinder and is connected to the exhaust port 7 of the corresponding cylinder. The common exhaust passage 23 includes a turbine 15b of the exhaust turbocharger 15 driven by the exhaust gas and a three-way catalyst for purifying the exhaust gas in order from the upstream side in the flow direction of the exhaust gas. The exhaust gas purifying device 24 used is interposed.

  Further, the engine CE has an EGR device 26 that recirculates a part of the exhaust gas in the common exhaust passage 23 to the intake system as EGR gas for the main purpose of reducing the amount of NOx generated by the combustion of the air-fuel mixture. Is provided. The EGR device 26 is provided with an EGR passage 27 serving as an EGR gas flow path. Here, the upstream end of the EGR passage 27 (as viewed in the flow direction of the EGR gas) is connected to the common exhaust passage 23 on the upstream side (as viewed in the flow direction of the exhaust gas) from the turbine 15b. On the other hand, the downstream end of the EGR passage 27 is connected to the surge tank 19. In the EGR passage 27, a water-cooled EGR cooler 28 that cools high-temperature (for example, 600 to 800 ° C.) EGR gas and an EGR gas that controls the amount of EGR gas in order from the upstream side in the flow direction of the EGR gas. A control valve 29 is provided.

  The engine CE is provided with a control unit 30 including a computer. The control unit 30 is a comprehensive control device for the engine CE, and performs various controls of the engine CE and various devices or devices related thereto, such as fuel injection control, ignition timing control, and the like. Yes. However, control methods for general control of the engine CE and the like are well known to those skilled in the art, and are not the gist of the present invention, and thus the description thereof is omitted.

  Next, a specific structure of the electric supercharger 14 will be described with reference to FIG. As shown in FIG. 2, the electric supercharger 14 pressurizes the intake air sucked in from the suction port 31 in the direction indicated by the arrow A1, and discharges it from the discharge port 32 in the direction indicated by the arrow A2. 33 and an electric motor unit 34 that is integrally formed with the compressor unit 33 and that rotationally drives the compressor unit 33.

  Although not shown, a voltage control unit (boost circuit unit) is provided in the motor unit 34. This voltage control unit boosts the power supplied from the battery 35 (see FIG. 3) to the motor unit 34. That is, although the output voltage of the battery 35 is approximately 12V, it is inefficient to drive the motor unit 34 at 12V. Therefore, in the electric supercharger 14, the 12V output voltage of the battery 35 is supplied to the voltage control unit. By raising the voltage to 24V, the current value is amplified to increase the efficiency. For this reason, when the electric supercharger 14 is operated, a considerable amount of heat is generated in the motor unit 34 or the voltage control unit.

  The motor unit 34 is provided with a cooling water jacket 36 (electric supercharger cooling unit) for cooling the motor unit 34 and the voltage control unit with cooling water. That is, the electric supercharger 14 is a water cooling type. As described above, the motor unit 34 including the voltage control unit is cooled by the low-temperature cooling water, so that the motor unit 34 or the voltage control unit is effectively cooled (for example, to 150 ° C. or less). The durability or reliability can be improved. The voltage control unit may be formed separately from the motor unit 34, and an air-cooled or water-cooled cooling unit may be provided in the voltage control unit to individually cool the voltage control unit.

  Hereinafter, referring to FIG. 3, various devices or devices such as the engine CE, the electric supercharger 14, the exhaust turbocharger 15, the EGR passage 27, the EGR cooler 28, and the cooling water supply system thereof in the engine room are described. The arrangement structure will be described. Hereinafter, for convenience, in FIG. 3, the front side (intake manifold side as viewed in the engine width direction) and rear side (exhaust manifold side as viewed in the engine width direction) of the vehicle are respectively referred to as “front” and “rear”. I will say. Further, the left side and the right side of the vehicle toward the front of the vehicle are referred to as “left” and “right”, respectively.

  As shown in FIG. 3, the engine CE is mounted horizontally in the engine room 37 of the vehicle. That is, the engine CE is arranged such that the crankshaft 10 (see FIG. 1) extends in the left-right direction. An intake manifold 39 is attached to the front side of the engine main body 38 (portion covered by the cylinder head and the cylinder block) arranged to be longitudinal in the left-right direction, and an exhaust manifold 40 is attached to the rear side. ing. On the left side of the left end portion of the engine main body 38, a water-cooled EGR cooler 28 is disposed in the vicinity of the left end portion so as to be longitudinal in the front-rear direction.

  In the vicinity of the right end of the engine main body 38, cooling water cooled by a radiator (not shown) is supplied to the rear surface of the engine main body 38 to each required cooling part (such as a cylinder head and a water jacket of a cylinder block). A water pump 41 is provided. As will be described later, the water pump 41 also supplies cooling water to the electric supercharger 14 and the EGR cooler 28.

  Although not shown in detail, the upstream end 12 a of the common intake passage 12 opens to the left from the left wall surface of the engine room 37 on the slightly front side of the engine main body 38. Further, behind the engine main body 38, a compressor 15a and a turbine 15b constituting the exhaust turbocharger 15 are arranged in such a posture that a common rotating shaft extends in the left-right direction. On the left side of the engine CE on the rear side of the engine main body 38, the electric supercharger 14 is disposed in such a posture that the rotation shaft of the compressor unit 33 or the motor unit 34 extends in the left-right direction.

  On the left side of the electric supercharger 14, a battery 35 is disposed in the vicinity thereof. Thus, since the electric supercharger 14 is disposed in the vicinity of the battery 35, the wiring or power distribution structure for supplying electric power to the electric supercharger 14 can be made compact or simplified. In addition, the electric supercharger 14 and the battery 35 are disposed in the vicinity of the front side of the suspension tower 43 of the vehicle. In the vicinity of the suspension tower 43, vibrations are unlikely to occur in the vehicle body. Therefore, the vibration of the electric supercharger 14 disposed in the vicinity of the suspension tower 43 can be reduced or suppressed, and the motor section 34 is relatively weak against vibration. The durability or reliability of the voltage controller can be improved.

  Hereinafter, the arrangement structure of the cooling water supply mechanism that supplies the cooling water to the cooling water jacket 36 and the EGR cooler 28 of the electric supercharger 14 in the engine room 37 will be specifically described. This cooling water supply structure is provided with a cooling water passage 45 for supplying and discharging cooling water to and from the cooling water jacket 36 and the EGR cooler 28. The cooling water passage 45 includes an upstream side cooling water passage 45a, an intermediate cooling water passage 45b, and a downstream side cooling water passage 45c.

  As viewed in the flow direction of the cooling water, the upstream end (cooling water intake) of the upstream side cooling water passage 45a is connected to the discharge part 41a of the water pump 41, and the downstream end is connected to the cooling water jacket 36 (cooling water inlet part). Has been. The upstream end of the intermediate cooling water passage 45 b is connected to the cooling water jacket 36 (cooling water outlet portion), and the downstream end is connected to the cooling water introduction portion 28 a of the EGR cooler 28. The upstream end of the downstream side cooling water passage 45c is connected to the cooling water outflow portion 28b of the EGR cooler 28, and the downstream end is connected to a cooling water guide passage (not shown) for guiding engine cooling water to a radiator (not shown). It is connected.

  In the cooling water supply mechanism or the cooling water passage 45, the upstream side cooling water passage 45 a is generally or entirely disposed so as to extend in the left-right direction on the rear side of the engine main body 38. The intermediate cooling water passage 45 b is disposed on the left side of the engine main body 38 and the EGR cooler 28, generally on the rear side of the engine main body 38. The downstream-side cooling water passage 45 c is disposed on the left side of the engine main body 38 and the EGR cooler 28, generally on the front side of the engine main body 38.

  In the arrangement structure of the cooling water passage 45, on the right side of the EGR cooler 28, the upstream side cooling water passage 45 a supplies the cooling water directly from the water pump 41 to the EGR cooler 28 (cools the electric supercharger 14. If not, the arrangement is almost the same as the cooling water passage. That is, this portion of the upstream side cooling water passage 45a has an arrangement that is substantially the same as the conventional cooling water passage that directly connects the water pump 41 and the EGR cooler 28. Further, the downstream side cooling water passage 45c has the same arrangement form as the conventional cooling water passage.

  Therefore, the cooling water passage 45 in the first embodiment basically includes an upstream side cooling water passage 45a and an intermediate cooling water passage 45b on the left side of the EGR cooler 28 in general with respect to the conventional cooling water passage. Can only be formed. That is, the motor unit 34 and the voltage control unit of the electric supercharger 14 can be cooled with the cooling water by using or sharing part or most of the cooling water passage for the original EGR cooler 28. Therefore, it is possible to effectively cool the motor unit 34 and the voltage control unit while simplifying the structure of the cooling water passage 45 and the structure of the engine CE as much as possible.

  In the first embodiment, the electric supercharger 14 is provided in the common intake passage 12 upstream of the compressor 15a of the exhaust turbocharger 15, but is downstream of the compressor 15a (upstream of the intercooler 16). ) May be provided in the common intake passage 12.

  As described above, according to the first embodiment, a part or most of the cooling water passage 45 for the original EGR cooler is used or shared, and the cooling water jacket 36 that cools the motor unit 34 and the voltage control unit has a low temperature. Cooling water can be supplied, and the cooling of the motor unit 34 and the voltage control unit can be effectively performed while simplifying the structure of the cooling water passage 45 and the structure of the engine CE as much as possible.

(Embodiment 2)
Hereinafter, the second embodiment of the present invention will be described with reference to FIG. However, the second embodiment is provided with an EGR cooler intercooler that cools the high-temperature cooling water that has flowed out of the EGR cooler 28, and the cooling water jacket 36 and the EGR cooler 28 of the electric supercharger 14. Except for the difference in the order in which the cooling water is supplied and the difference that accompanies them, this is substantially the same as in the first embodiment. Therefore, in the following, in order to avoid duplication of explanation, differences from the first embodiment will be mainly described.

  As shown in FIG. 4, in the second embodiment, an air-cooled EGR cooler intercooler 47 that cools high-temperature cooling water that has flowed out of the EGR cooler 28 is provided above the engine main body 38. The cooling water passage 45 includes four partial cooling water passages, that is, first to fourth cooling water passages 45d to 45g.

  The upstream end (cooling water intake) of the first cooling water passage 45d located on the most upstream side in the flow direction of the cooling water is connected to the discharge portion 41a of the water pump 41, and the downstream end is the cooling water of the EGR cooler 28. It is connected to the introduction part 28a. The upstream end of the second cooling water passage 45e is connected to the cooling water outflow portion 28b of the EGR cooler 28, and the downstream end is connected to the cooling water inlet portion of the intercooler 47 for EGR cooler. The upstream end of the third coolant passage 45f is connected to the coolant outlet portion of the EGR cooler intercooler 47, and the downstream end is connected to the coolant jacket 36 (coolant inlet portion) of the electric supercharger 14. The upstream end of the fourth cooling water passage 45g located on the most downstream side is connected to a cooling water jacket 36 (cooling water outlet), and the downstream end is a cooling water guide for guiding engine cooling water to a radiator (not shown). It is connected to a passage (not shown).

  Therefore, in the second embodiment, the cooling water discharged from the water pump 41 first flows into the EGR cooler 28 to cool the EGR gas. At that time, the temperature of the cooling water increases due to heat exchange and becomes high. Then, the high-temperature cooling water that has flowed out of the EGR cooler 28 flows into the EGR cooler intercooler 47, where it is cooled to a low temperature. The low-temperature cooling water that has flowed out of the EGR cooler intercooler 47 flows into the cooling water jacket 36 of the electric supercharger 14 and effectively cools the motor unit 34 and the voltage control unit of the electric supercharger 14. The other points are the same as in the first embodiment.

  As described above, also in the second embodiment, as in the first embodiment, the motor unit 34 and the voltage control unit are cooled by using or sharing part or most of the cooling water passage 45 for the original EGR cooler. Cooling water can be supplied to the cooling water jacket 36, and the cooling of the motor section 34 and the voltage control section can be effectively performed while simplifying the structure of the cooling water passage 45 and the structure of the engine CE as much as possible. .

(Embodiment 3)
Hereinafter, Embodiment 3 of the present invention will be described with reference to FIGS. 5 and 6. However, the third embodiment is substantially the same as the first embodiment, except that the engine is not an ignition spark engine but a diesel engine, and the differences associated therewith. Therefore, in the following, in order to avoid duplication of explanation, differences from the first embodiment will be mainly described.

  As shown in FIGS. 5 and 6, in a diesel engine DE (hereinafter referred to as “engine DE” for short), when the intake valve 1 is opened, a fuel combustion fuel is introduced into the combustion chamber 3 from the intake port 2. Air (intake air) is inhaled. Then, the intake air in the combustion chamber 3 is compressed by the piston 4 to be in a high temperature / high pressure state. Then, near the top dead center of the compression stroke, fuel (light oil or the like) is injected from the fuel injection valve 51 into the high-temperature and high-pressure intake air in the combustion chamber 3, and this fuel self-ignites and burns. The engine DE is not provided with a spark plug. Gas generated by combustion, that is, exhaust gas, is discharged to the exhaust port 7 when the exhaust valve 6 is opened. These series of operations are repeated, and the piston 4 repeats reciprocating motion in the cylinder 8. The mechanism for converting the reciprocating motion of the piston 4 into the rotational motion of the crankshaft 10 and the mechanism for starting the engine DE are the same as those of the engine CE according to the first embodiment.

  In the intake system of the engine DE, an electromagnetic intake control valve 52 is provided in the common intake passage 12. The intake control valve 52 is disposed on the downstream side of the air flow sensor 17 and on the upstream side of the connection portion with the EGR passage 56 of the second EGR device 55 described later. The common intake passage 12 is not provided with a throttle valve. The independent intake passage 20 is not provided with a fuel injection valve. Other configurations of the intake system of the engine DE are the same as those of the engine CE according to the first embodiment.

  In the exhaust system of the engine DE, an exhaust gas purification catalyst 53 for purifying exhaust gas and a particulate filter 54 are provided in the common exhaust passage 23 on the downstream side of the turbine 15b of the exhaust turbocharger 15. The exhaust gas purification catalyst 53 and the particulate filter 54 including the oxidation catalyst are arranged in one casing having heat resistance, and when, for example, the differential pressure before and after the particulate filter 54 exceeds a set value, The exhaust gas purification catalyst 53 is brought into an operating state (for example, fuel injection in the expansion stroke), and the particulate (soot) collected by the particulate filter 54 is burned and removed. Other configurations of the exhaust system of the engine DE are the same as those of the engine CE according to the first embodiment.

  Further, the engine DE is caused to recirculate a part of the exhaust gas in the common exhaust passage 23 as EGR gas to the intake system (surge tank 19) mainly for the purpose of reducing the amount of NOx generated by fuel combustion. A first EGR device 26 including an EGR passage 27, a water-cooled EGR cooler 28, and an EGR control valve 29 is provided. The configuration and function of the first EGR device 26 are basically the same as those of the EGR device 26 of the engine CE according to the first embodiment.

  Furthermore, the engine DE is provided with a second EGR device 55 mainly for the purpose of reducing the amount of NOx generated by the combustion of fuel. The second EGR device 55 is provided with an EGR passage 56 serving as an EGR gas flow path. Here, the upstream end of the EGR passage 56 (as viewed in the flow direction of the EGR gas) is connected to the common exhaust passage 23 on the downstream side of the particulate filter 54. On the other hand, the downstream end of the EGR passage 56 is connected to the common intake passage 12 on the downstream side (as viewed in the direction of intake air flow) from the intake control valve 52. The EGR passage 56 is provided with an air-cooled EGR cooler 57 that cools the EGR gas and an EGR control valve 58 that controls the amount of EGR gas in order from the upstream side in the flow direction of the EGR gas. An electric supercharger 14 is provided in the common intake passage 12 slightly upstream of the compressor 15 a of the exhaust turbocharger 15. The electric supercharger 14 or its cooling mechanism is the same as in the first embodiment.

  The arrangement structure of various devices or devices such as the engine DE, the electric supercharger 14, the exhaust turbocharger 15, the EGR passage 27, the EGR cooler 28, and its cooling water supply system in the engine room 37 is the same as that of the first embodiment. It is the same.

  Thus, also in the third embodiment, as in the first embodiment, the motor unit 34 and the voltage control unit are cooled by utilizing or sharing part or most of the cooling water passage 45 for the original EGR cooler. Cooling water can be supplied to the cooling water jacket 36, and the cooling of the motor section 34 and the voltage control section can be effectively performed while simplifying the structure of the cooling water passage 45 and the structure of the engine CE as much as possible. .

It is a schematic diagram which shows the system configuration | structure of the spark ignition type engine provided with the supercharging device which concerns on Embodiment 1 of this invention. It is a perspective view of the electric supercharger of the engine shown in FIG. 1 is a schematic plan view showing an arrangement structure of an engine, an electric supercharger, an exhaust turbocharger, an EGR passage, an EGR cooler, a cooling water supply system, and the like in an engine room according to Embodiment 1. FIG. 6 is a schematic plan view showing an arrangement structure of an engine, an electric supercharger, an exhaust turbocharger, an EGR passage, an EGR cooler, a cooling water supply system thereof, and the like in an engine room according to Embodiment 2. FIG. It is a schematic diagram which shows the system configuration | structure of the diesel engine provided with the supercharging apparatus which concerns on Embodiment 3 of this invention. FIG. 6 is a schematic plan view showing an arrangement structure of an engine, an electric supercharger, an exhaust turbocharger, an EGR passage, an EGR cooler, a cooling water supply system, and the like in an engine room according to a third embodiment.

Explanation of symbols

  CE spark ignition engine, DE diesel engine, 1 intake valve, 2 intake port, 3 combustion chamber, 4 piston, 5 spark plug, 6 exhaust valve, 7 exhaust port, 8 cylinder, 9 connecting rod, 10 crankshaft, 11 engine starter , 12 Common intake passage, 13 Air cleaner, 14 Electric supercharger, 15 Exhaust turbocharger, 15a Compressor (pump), 15b Turbine, 16 Intercooler, 17 Air flow sensor, 18 Throttle valve, 19 Surge tank, 20 Independent intake Passage, 21 fuel injection valve, 23 common exhaust passage, 24 exhaust gas purification device, 26 EGR device (first EGR device), 27 second EGR passage, 28 EGR cooler, 29 EGR control valve, 30 control unit, 31 Inlet port, 32 outlet port, 3 Compressor, 34 Motor, 35 Battery, 36 Cooling water jacket, 37 Engine room, 38 Engine body, 39 Intake manifold, 40 Exhaust manifold, 41 Water pump, 43 Suspension tower, 45 Cooling water passage, 45a Upstream cooling water Passage, 45b intermediate cooling water passage, 45c downstream cooling water passage, 45d first cooling water passage, 45e second cooling water passage, 45f third cooling water passage, 45g fourth cooling water passage, 47 intercooler for EGR cooler, 51 fuel injection valve, 52 intake control valve, 53 exhaust gas purification catalyst, 54 particulate filter, 55 second EGR device, 56 EGR passage, 57 EGR cooler, 58 EGR control valve.

Claims (4)

An electric supercharger having a compressor unit, a motor unit that drives the compressor unit, and a booster circuit unit that boosts the power supplied from the power source to the motor unit;
An EGR passage that recirculates part of the exhaust gas to the intake system;
A water-cooled EGR cooler disposed in the EGR passage;
A cooling water passage for supplying cooling water to the EGR cooler,
The cooling water passage supplies the cooling water to an electric supercharger cooling unit that cools at least one of the motor unit and the booster circuit unit, and then supplies the cooling water to an EGR cooler. apparatus. An electric supercharger having a compressor unit, a motor unit that drives the compressor unit, and a booster circuit unit that boosts the power supplied from the power source to the motor unit;
An EGR passage that recirculates part of the exhaust gas to the intake system;
A water-cooled EGR cooler disposed in the EGR passage;
A cooling water passage for supplying cooling water to the EGR cooler;
An EGR cooler intercooler that cools the cooling water flowing out from the EGR cooler,
The cooling water passage supplies the cooling water to the EGR cooler, and then supplies the cooling water to the electric supercharger cooling unit that cools at least one of the motor unit and the booster circuit unit via the EGR cooler intercooler. A supercharging device for an engine. The EGR passage is disposed so as to connect the intake passage and the exhaust passage on one end side of the engine when viewed in the cylinder arrangement direction of the engine.
The cooling water intake portion of the cooling water passage is provided on the other end side of the engine as viewed in the cylinder arrangement direction of the engine,
The electric supercharger is located on the side where the cooling water passage connecting the cooling water intake portion of the cooling water passage and the cooling water introduction portion of the EGR cooler is disposed in a direction perpendicular to the cylinder arrangement direction of the engine. The supercharging device for an engine according to claim 1 or 2, wherein the supercharging device for the engine according to claim 1 or 2 is disposed. An exhaust turbocharger is installed,
The compressor portion of the electric supercharger is disposed in the intake passage upstream of the compressor of the exhaust turbocharger,
4. The engine supercharging device according to claim 3, wherein the cooling water intake portion of the cooling water passage is arranged on a side where the exhaust passage is located in a direction perpendicular to the cylinder arrangement direction of the engine.

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