JP2009002305A - Supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress solidification of oil sticking to a diffuser passage in a supercharger. <P>SOLUTION: The supercharger comprises: a variable capacity type turbocharger 27 constructed by providing a compressor wheel 67 on an air intake passage 55 of a compressor housing 51 so as to freely rotate, supporting a turbine wheel 68 on an exhaust passage 61 of a turbine housing 58 so as to freely rotate, and connecting the compressor wheel 67 and the turbine wheel 68 by a rotating shaft 65 so as to allow integral rotation; a diffuser passage 57 which communicates with the air intake passage 55 to convert a dynamic pressure of a fluid to a static pressure; and a ceramic heater 81 for incinerating an oil component attached to the wall face of this diffuser passage. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a turbocharger that compresses and supplies fluid by rotating a turbine wheel with exhaust gas and rotating a compressor wheel with this rotational force.

  Some conventional internal combustion engines include a supercharger (turbocharger) in order to improve operating performance. The supercharger provided in the internal combustion engine has a turbine wheel that rotates using the pressure of exhaust gas, and a compressor wheel that can compress air by rotating with the rotation of the turbine wheel. . Therefore, when the internal combustion engine is operated, the turbine wheel is rotated by the exhaust gas, the compressor wheel is rotated by the rotation of the turbine wheel, the air is compressed, and the compressed air is supplied to the combustion chamber. Since the amount of fuel injection is increased by increasing the amount of intake air, the output torque of the internal combustion engine can be increased to improve the operating performance.

  By the way, in an internal combustion engine, unburned gas, oil mist, etc. generated inside leaks from the combustion chamber into the crankcase during the compression and combustion stroke and becomes blow-by gas, which deteriorates engine oil and corrodes metal. . Therefore, blow-by gas is sucked into the intake passage using the intake pipe negative pressure and reduced.

  However, in an internal combustion engine provided with a supercharger, the intake passage upstream of the supercharger has a negative pressure, so blow-by gas is discharged into the intake passage upstream of the compressor wheel in the supercharger. ing. Therefore, when this blow-by gas passes through the diffuser passage of the compressor, oil contained in the blow-by gas adheres to the wall surface of the diffuser passage. The oil adhering to the wall surface of the diffuser passage is heated and carbonized by the high-temperature and high-pressure air compressed by the compressor wheel, and solidifies (coking) to reduce the passage area of the diffuser passage, thereby reducing the air intake resistance. There is a problem of becoming.

  In order to solve the above-described problem, for example, there is one described in Patent Document 1 below. The turbocharger described in Patent Document 1 includes a diffuser portion that includes a diffuser passage and a seal plate adjacent portion that faces the diffuser passage and a housing adjacent portion, and the seal plate adjacent portion and the housing adjacent portion. By forming an oil-repellent film with a material that repels at least oil mist that has no affinity for engine oil at the contact portion, and by providing a cooling path at least at the seal plate adjacent portion, this seal plate adjacent portion is cooled, This prevents oil mist from adhering to the diffuser portion so that a carbonized layer is not formed.

JP 2004-044551 A

  However, blow-by gas contains not only unburned gas and oil mist but also a large amount of evaporated water, so that it repels the seal plate adjacent part and the housing adjacent part as in the conventional turbocharger described above. Even if an oil film is formed, it is difficult to repel oil mist contained in blow-by gas. That is, when the moisture contained in the blow-by gas comes into contact with the oil repellent film at the seal plate adjacent portion and the housing adjacent portion, a water film is formed on the surface of the oil repellent film, and oil mist adheres to the water film. When oil mist and moisture are mixed, the oil repellent film cannot repel the oil mist and adheres to it.

  An object of this invention is to provide the supercharger which can suppress solidification of the oil adhering to a diffuser channel | path.

  In order to solve the above-described problems and achieve the object, a supercharger according to the present invention includes a housing provided independently of an intake passage and an exhaust passage, a compressor wheel provided on the intake passage, and an exhaust passage. A turbo wheel provided on the housing and rotatably supported by the housing and having a rotating shaft that connects the compressor wheel and the turbine wheel. A diffuser passage for converting to static pressure is provided, and a ceramic heater for incinerating oil components adhering to the wall surface of the diffuser passage is provided.

  In the supercharger of the present invention, when the temperature of the fluid flowing through the intake passage is equal to or lower than a predetermined temperature, and the speed of the fluid is equal to or lower than a predetermined speed, the ceramic heater The oil component adhering to the wall surface of the diffuser passage is incinerated.

  The supercharger of the present invention is characterized in that an oil repellent film or a hydrophilic film is provided on at least one of the upstream and downstream sides of the fluid in the diffuser passage.

  The turbocharger according to the present invention includes a housing provided independently of an intake passage and an exhaust passage, a compressor wheel provided on the intake passage, a turbine wheel provided on the exhaust passage, and a rotatable in the housing. Is provided with a diffuser passage that communicates with the intake passage and converts a dynamic pressure of fluid into a static pressure, and is provided with a rotating shaft that connects the compressor wheel and the turbine wheel. A hydrophilic film having hydrophilicity is provided on the wall surface of the diffuser passage.

  The supercharger according to the present invention includes a housing provided independently of an intake passage and an exhaust passage, a compressor wheel provided on the intake passage, a turbine wheel provided on the exhaust passage, and a housing rotatably supported by the housing. And a diffuser passage that communicates with the intake passage and converts a dynamic pressure of fluid to a static pressure in a supercharger that includes a rotation shaft that connects the compressor wheel and the turbine wheel, and the diffuser passage. A water / oil repellent film having water repellency and oil repellency is provided on the wall surface.

  According to the supercharger of the present invention, a diffuser passage that communicates with the intake passage of the housing and converts the dynamic pressure of the fluid into a static pressure is provided, and a ceramic heater that incinerates the oil component adhering to the wall surface of the diffuser passage Therefore, even if the oil component contained in the blow-by gas adheres to the wall surface of the diffuser passage, solidification of the oil attached to the diffuser passage can be suppressed by incinerating the attached oil component by the ceramic heater.

  Further, according to the supercharger of the present invention, since the hydrophilic film having hydrophilicity is provided on the wall surface of the diffuser passage, when blowby gas comes into contact with the wall surface of the diffuser passage, moisture contained in the blowby gas is brought into contact with the hydrophilic film on the wall surface. Adheres to form a water film, and the oil component contained in the blow-by gas is prevented from adhering by flowing on the surface of the water film, and solidification of the oil adhering to the diffuser passage can be suppressed.

  Further, according to the supercharger of the present invention, since the water repellent and oil repellent film having water repellency and oil repellency is provided on the wall surface of the diffuser passage, when blowby gas comes into contact with the wall surface of the diffuser passage, the water and oil repellent film on the wall surface Even if the moisture and oil components contained in the blowby gas come into contact with each other, they are repelled and prevented from adhering, and solidification of the oil adhering to the diffuser passage can be suppressed.

  Embodiments of a supercharger according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this Example.

  FIG. 1 is a cross-sectional view illustrating a supercharger according to a first embodiment of the present invention, and FIG. 2 is a schematic configuration diagram illustrating an internal combustion engine to which the supercharger according to the first embodiment is applied.

  In the internal combustion engine of the first embodiment, as shown in FIG. 2, in a diesel engine 11 as an internal combustion engine, a cylinder head 13 is fastened on a cylinder block 12, and pistons 15 are fitted in a plurality of cylinder bores 14 so as to be vertically movable. Are configured together. A crankcase (not shown) is fastened to the lower part of the cylinder block 12, and a crankshaft is rotatably supported in the crankcase. Each piston 15 is connected to the crankshaft via a connecting rod 16. Yes.

  The cylinder block 12, the cylinder head 13, and the piston 15 constitute a plurality of combustion chambers 17. The combustion chamber 17 is formed with an intake port 18 and an exhaust port 19 facing each other at the upper portion. The lower ends of the intake valve 20 and the exhaust valve 21 are located with respect to the exhaust port 19. The intake valve 20 and the exhaust valve 21 are supported by the cylinder head 13 so as to be movable in the axial direction, and are urged and supported in a direction to close the intake port 18 and the exhaust port 19. Further, an intake cam shaft and an exhaust cam shaft (not shown) are rotatably supported on the cylinder head 13, and the intake cam and the exhaust cam are in contact with upper ends of the intake valve 20 and the exhaust valve 21.

  Therefore, when the intake cam shaft and the exhaust cam shaft rotate in synchronization with the diesel engine 11, the intake cam and the exhaust cam move up and down the intake valve 20 and the exhaust valve 21 at a predetermined timing, so that the intake port 18 and the exhaust port 19 can be opened and closed to allow communication between the intake port 18 and the combustion chamber 17, and the combustion chamber 17 and the exhaust port 19.

  An intake pipe 22 is connected to the intake port 18, and an air cleaner 23 is attached to an air intake port of the intake pipe 22. A throttle valve 24 is provided on the downstream side of the air cleaner 23. Each cylinder head 13 is provided with an injector 25 that can inject light oil as fuel into each combustion chamber 17 at a high pressure. Each injector 25 is connected to a fuel pump via a delivery pipe and a fuel supply pipe (not shown), and the fuel pump is driven by the diesel engine 11. On the other hand, an exhaust pipe 26 is connected to the exhaust port 19.

  The intake pipe 22 and the exhaust pipe 26 are provided with a variable capacity turbocharger (supercharger) 27. An intercooler 28 is provided in the intake pipe 22 on the downstream side of the variable capacity turbocharger 27 to cool the air that has been compressed by the variable capacity turbocharger 27 and has become high temperature and high pressure.

  The exhaust pipe 26 is provided with two catalyst devices 29 and 30 that purify harmful substances contained in the exhaust gas, and are arranged in series. The first catalytic device 29 is an NOx storage reduction catalyst that stores NOx in the exhaust gas when the exhaust air-fuel ratio is lean and releases the stored NOx when the oxygen concentration in the exhaust gas decreases. The fuel is reduced by the added fuel (reducing oil in this embodiment) as a reducing agent. The second catalytic device 30 is a NOx storage reduction catalyst having a particulate filter, which collects particulates (PM: particulates) in exhaust gas, particularly black smoke, and when the exhaust air-fuel ratio is lean. NOx in the exhaust gas is occluded, and when the oxygen concentration in the exhaust gas decreases, the occluded NOx is released and reduced by the added fuel.

  The first catalyst device 29 and the second catalyst device 30 release the stored NOx when the oxygen concentration in the exhaust gas is reduced, and reduce the released NOx with fuel. The cylinder head 13 is provided with a fuel addition valve 31 for injecting fuel 19 (light oil as a reducing agent). The fuel addition valve 31 is connected to a fuel pump via a fuel supply pipe (not shown).

  A high-pressure exhaust gas recirculation (EGR) device 32 that returns exhaust gas to the intake system is provided. The high pressure EGR device 32 connects an upstream side of the variable displacement turbocharger 27 in the exhaust pipe 26 and a downstream side of the throttle valve 24 in the intake pipe 22 to recirculate a part of the exhaust gas to the intake system. 33, an EGR valve 34 provided in the EGR passage 33, and an EGR cooler 35 provided in the EGR passage 33 for cooling the exhaust gas.

  Further, a PCV (Positive Crankcase Ventilation) passage 36 is provided between the inside of the diesel engine 11 and the intake pipe 22 upstream of the variable displacement turbocharger 27, and a PCV valve is provided in the PCV passage 36. 37 is provided.

  By the way, an electronic control unit (ECU) 38 is mounted on the vehicle, and the ECU 38 can control the fuel injection of each injector 25 and the fuel addition valve 31 according to the engine operating state. That is, an air flow sensor 39 is mounted on the upstream side of the intake pipe 22 and outputs the measured intake air amount to the ECU 38. The throttle valve 24 is provided with a throttle position sensor 40, and the accelerator pedal is provided with an accelerator position sensor 41, which outputs the current throttle opening and accelerator opening to the ECU 38. Further, a crank angle sensor 42 is provided on the crankshaft, and the detected crank angle is output to the ECU 38. The ECU 38 calculates the engine speed based on the crank angle. Further, the cylinder block 12 is provided with a water temperature sensor 43 and outputs the detected engine cooling water temperature to the ECU 38.

  Further, the ECU 38 can control the variable displacement turbocharger 27, the high pressure EGR device 32 (EGR valve 34), and the PCV valve 37 in accordance with the engine operating state. That is, the supercharging pressure is controlled by setting the vane opening in the variable displacement turbocharger 27 according to the engine operating state, and the EGR amount is set by setting the opening of the EGR valve 34 in the high pressure EGR device 32. By controlling the opening / closing of the PCV valve 37, the blow-by gas reduction timing is controlled.

  Here, the variable capacity turbocharger 27 described above will be described in detail. In this variable displacement turbocharger 27, as shown in FIG. 1, a compressor housing 51 is composed of a cylindrical housing body 52, a ring-shaped connecting member 53, and a disc-shaped seal plate 54. Has been. That is, the housing body 52 is formed with an intake passage 55 communicating with the upstream side of the intake pipe 22 (see FIG. 2), and the connecting member 53 is fixed inside the housing body 52 to form a spiral shape. Thus, a scroll passage 56 communicating with the downstream side of the intake pipe 22 (see FIG. 2) is formed, and a seal plate 54 is fixed to the end of the housing main body 52 so that the intake passage 55 and the scroll passage 56 communicate with each other. A diffuser passage 57 for converting the dynamic pressure of the compressed air (fluid) into a static pressure is formed.

  On the other hand, the turbine housing 58 includes a housing body 59 having a cylindrical shape and a nozzle plate 60 having a disk shape. That is, the housing main body 59 is formed with an exhaust passage 61 communicating with the downstream side of the exhaust pipe 26 (see FIG. 2), and in a spiral shape, communicating with the upstream side of the exhaust pipe 26 (see FIG. 2). A scroll passage 62 is formed, and the nozzle plate 60 is fixed to the end of the housing main body 59, thereby forming a connection passage 63 that connects the exhaust passage 61 and the scroll passage 62.

  The compressor housing 51 and the turbine housing 58 are connected by a center housing 64 having a cylindrical shape, whereby the housing of the present invention is configured.

  A rotation shaft 65 is rotatably supported by a plurality of bearings 66 along the axial direction of the center housing 64. A compressor wheel 67 having a plurality of compressor blades 67 a is fixed to one end of the rotary shaft 65 so as to be positioned in the intake passage 55 of the compressor housing 51, while A turbine wheel 68 having a plurality of turbine blades 68 a is fixed to the end portion so as to be integrally rotatable so as to be positioned in the exhaust passage 61 of the turbine housing 58. In this case, the rotation shaft 65, the compressor wheel 67, and the turbine wheel 68 can be rotated with the same rotation center.

  A variable nozzle mechanism 69 is provided on the center housing 64 side of the turbine housing 58. The variable nozzle mechanism 69 includes a plurality of vanes 70 disposed in a connection passage 63 through which exhaust flows from the scroll passage 62 to the turbine wheel 68, and a connection shaft that holds the vanes 70 with respect to the nozzle plate 60 so as to be swingable. 71 and a unison ring 73 that rotates the connecting shaft 71 via an arm 72 fixed to the end of each connecting shaft 71. The unison ring 73 is connected to a drive device (not shown) via a link 74. Therefore, when the unison ring 73 is rotated by the drive device via the link 74, the arm 72 engaged with the unison ring 73 is swung around the connecting shaft 71, and the opening degree of the plurality of vanes 70 is changed. can do.

  When the exhaust gas discharged from the combustion chamber 17 to the exhaust pipe 26 reaches the turbine wheel 68 of the variable capacity turbocharger 27, the turbine wheel 68 is rotated by the exhaust gas, and this rotational force is transmitted to the compressor via the rotary shaft 65. This is transmitted to the wheel 67, and the compressor wheel 67 rotates. Then, the air taken in from the intake passage 55 is compressed by the rotating compressor wheel 67 and can be supercharged into the combustion chamber 17 through the intake pipe 22.

  In the internal combustion engine of the present embodiment configured as described above, as shown in FIGS. 1 and 2, unburned gas, oil mist, and the like are compressed inside the diesel engine 11 from the combustion chamber 17 in the crankcase during the combustion stroke. It leaks into and becomes blow-by gas. Therefore, the ECU 38 opens the PCV valve 37 according to the engine operating state, thereby sucking the blow-by gas in the diesel engine 11 into the intake pipe 22 through the PCV passage 36 by the intake negative pressure and passing through the intake pipe 22 to the combustion chamber. Introduced into 17 and reduced.

  However, since this blow-by gas is sucked into the intake pipe 22 upstream of the compressor wheel 67 in the variable displacement turbocharger 27 through the PCV passage 36 due to the intake pipe negative pressure, this blow-by gas is sucked into the intake passage of the compressor housing 51. 55, when passing through the diffuser passage 57 and the scroll passage 56, the oil contained in the blow-by gas adheres to the wall surface of the passage. Then, the oil adhering to the wall surface of the passage is heated and carbonized by the high-temperature and high-pressure air compressed by the compressor wheel 67, and solidified (coking). In particular, the passage of the diffuser passage 57 having a narrow passage area. Narrows the area and becomes an intake resistance.

  Therefore, in the supercharger of the present embodiment, the diffuser passage 57 is provided with a ceramic heater 81 that incinerates the oil component adhering to the wall surface of the diffuser passage 57. The ceramic heater 81 is provided on all the wall surfaces of the diffuser passage 57 by coating, and is connected to the ECU 38 and a power source (not shown) via wiring (not shown). In this case, when the temperature of the intake air flowing through the intake passage 55 (or the diffuser passage 57) is equal to or lower than a predetermined temperature, and the intake air speed is equal to or lower than a predetermined predetermined speed, the ECU 38 By energizing the heater 81, the oil component adhering to the wall surface of the diffuser passage 57 is incinerated.

  That is, during the idling operation of the diesel engine 11, the diesel engine 11 itself is in a low temperature state or the engine load is low, so that the temperature of the intake air flowing through the intake passage 55 is equal to or lower than a predetermined temperature set in advance. Further, when the diesel engine 11 is idling, the throttle valve 24 is closed and the intake air amount is small, so that the intake air speed is less than or equal to a predetermined speed set in advance. Therefore, when the diesel engine 11 is idling, the oil adhering to the wall surface of the diffuser passage 57 is not carbonized because the intake air temperature is low, and the ceramic heater 81 is heated up because the intake air speed is low. If the ECU 38 energizes the ceramic heater 81 at this time, the oil component adhering to the wall surface of the diffuser passage 57 can be incinerated.

  Further, in the supercharger of this embodiment, the oil repellent film 82 is provided on the wall surface of the intake passage 55 upstream from the diffuser passage 57 and the oil repellent film 83 is provided on the wall surface of the scroll passage 56 downstream of the diffuser passage 57. It has been. The oil repellent films 82 and 83 have a property of repelling oil components without affinity. Therefore, the oil repellent films 82 and 83 can prevent the oil component contained in the blow-by gas from adhering to the wall surface of the intake passage 55 and the scroll passage 56.

  In this case, a hydrophilic film may be provided on the wall surface of the intake passage 55 and the wall surface of the scroll passage 56 instead of the oil repellent films 82 and 83. Therefore, water contained in the blow-by gas adheres to the wall surface of the intake passage 55 and the scroll passage 56 by the hydrophilic film to form a water film, and the oil component contained in the blow-by gas adheres by flowing on the surface of the water film. Can be prevented.

  Further, a ceramic heater and an oil repellent film or a hydrophilic film may be alternately provided on the wall surface of the diffuser passage 57 with respect to the flow direction of the intake air.

  In the supercharger of the present embodiment configured as described above, blow-by gas is generated inside the diesel engine 11, and this blow-by gas is passed through the PCV passage 36 by the intake negative pressure, and the variable displacement turbocharger 27 (compressor wheel 67). ) The air is sucked into the intake pipe 22 on the upstream side. The blow-by gas passes through the intake passage 55 of the variable capacity turbocharger 27 together with the intake air to the compressor wheel 67, and oil contained in the blow-by gas adheres to the wall surface of the diffuser passage 57. At this time, when the ECU 38 energizes the ceramic heater 81, the oil component attached to the wall surface of the diffuser passage 57 is incinerated.

  Further, when this blow-by gas is sucked into the intake pipe 22 and reaches the compressor wheel 67 through the intake passage 55 of the variable capacity turbocharger 27 together with the intake air, an oil repellent film is applied to the wall surface of the intake passage 55 and the wall surface of the scroll passage 56. Since 82 and 83 (or a hydrophilic film) are provided, the oil component is prevented from adhering to the wall surface of the intake passage 55 and the scroll passage 56.

  As described above, in the turbocharger according to the first embodiment, the compressor wheel 67 is rotatably provided on the intake passage 55 of the compressor housing 51 and the turbine wheel 68 is freely rotatable on the exhaust passage 61 of the turbine housing 58. The compressor wheel 67 and the turbine wheel 68 are connected to each other by a rotary shaft 65 so as to be integrally rotatable, and the variable displacement turbocharger 27 is configured. The diffuser communicates with the intake passage 55 to convert the fluid dynamic pressure into a static pressure. A passage 57 is provided, and a ceramic heater 81 for incinerating the oil component adhering to the wall surface of the diffuser passage is provided.

  Accordingly, when the blow-by gas of the diesel engine 11 is sucked into the intake pipe 22 through the PCV passage 36 due to the intake negative pressure and reaches the compressor wheel 67 through the intake passage 55 of the variable displacement turbocharger 27 together with the intake air, Even if the contained oil adheres to the wall surface of the diffuser passage 57, solidification of the oil attached to the diffuser passage 57 can be suppressed by incinerating the attached oil component by the ceramic heater 81.

  In the first embodiment, the ECU 38 controls the ceramic heater 81 when the temperature of the air flowing through the intake passage 55 is equal to or lower than a predetermined temperature and the air speed is equal to or lower than a predetermined speed. The oil component adhered to the wall surface of the diffuser passage 57 is incinerated. Therefore, when the temperature of the air flowing through the intake passage 55 is low, such as when the diesel engine 11 is idling, the oil adhering to the wall surface of the diffuser passage 57 is not carbonized, and when the air speed is low, When the temperature of the ceramic heater 81 is easily raised and the ECU 38 energizes the ceramic heater 81 at this time, the oil component adhering to the wall surface of the diffuser passage 57 can be surely incinerated.

  In the first embodiment, oil repellent films 82 and 83 (or hydrophilic films) are provided on the wall surface of the intake passage 55 and the wall surface of the scroll passage 56. Accordingly, it is possible to prevent oil components from adhering to the wall surface of the intake passage 55 and the scroll passage 56.

  Further, in the first embodiment, the ceramic heater and the oil repellent film or the hydrophilic film are alternately provided on the wall surface of the diffuser passage 57 with respect to the flow direction of the intake air, thereby preventing the oil component from adhering to the diffuser passage 57. It is possible to reduce the power consumption by shortening the energization time of the ceramic heater 81.

  FIG. 3 is a cross-sectional view illustrating a supercharger according to a second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the same function as what was demonstrated in the Example mentioned above, and the overlapping description is abbreviate | omitted.

  In the supercharger of the second embodiment, as shown in FIG. 3, a hydrophilic film 91 having hydrophilicity is provided on the wall surface of the diffuser passage 57 of the variable capacity turbocharger 27. Further, a hydrophilic film 92 is provided on the wall surface of the intake passage 55 upstream of the diffuser passage 57, and a hydrophilic film 93 is provided on the wall surface of the scroll passage 56 downstream of the diffuser passage 57. The hydrophilic films 92 and 93 have affinity and adsorb water components.

  Therefore, when blow-by gas is sucked into the intake pipe 22 upstream of the compressor wheel 67 of the variable displacement turbocharger 27 due to intake negative pressure, the blow-by gas passes through the intake passage 55 together with the intake air to the compressor wheel 67. As a result, the oil contained in the blow-by gas tends to adhere to the wall surface of the diffuser passage 57. At this time, water contained in the blow-by gas adheres to the hydrophilic film 91 of the diffuser passage 57 to form a water film, and the oil component contained in the blow-by gas adheres to the surface of the water film. The oil component adhering to the surface of the membrane is caused to flow, and the oil component is prevented from adhering to the wall surface of the diffuser passage 57.

  As described above, in the turbocharger according to the second embodiment, the compressor wheel 67 is rotatably provided on the intake passage 55 of the compressor housing 51 and the turbine wheel 68 is freely rotatable on the exhaust passage 61 of the turbine housing 58. The compressor wheel 67 and the turbine wheel 68 are connected to each other by a rotary shaft 65 so as to be integrally rotatable, and a diffuser passage 57 that communicates with the intake passage 55 and converts the dynamic pressure of fluid into static pressure is provided. A hydrophilic film 91 is provided on the wall surface of the passage.

  Accordingly, when the blow-by gas of the diesel engine 11 is sucked into the intake pipe 22 through the PCV passage 36 due to the intake negative pressure and reaches the compressor wheel 67 through the intake passage 55 of the variable displacement turbocharger 27 together with the intake air, The contained water adheres to the hydrophilic film 91 of the diffuser passage 57 to form a water film, and the oil component contained in the blow-by gas adheres to the surface of the water film, but is caused to flow by the flow velocity of the air. By preventing the oil component from adhering to the wall surface of 57, solidification of the oil adhering to the diffuser passage 57 can be suppressed.

  Further, in the supercharger of the present embodiment, a hydrophilic film 92 is provided on the wall surface of the intake passage 55 upstream of the diffuser passage 57 and a hydrophilic film 93 is provided on the wall surface of the scroll passage 56 downstream of the diffuser passage 57. It has been. Therefore, adhesion of the oil component contained in the blow-by gas to the wall surface of the intake passage 55 and the scroll passage 56 can be prevented by the hydrophilic films 92 and 93.

  FIG. 4 is a cross-sectional view illustrating a supercharger according to a third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the same function as what was demonstrated in the Example mentioned above, and the overlapping description is abbreviate | omitted.

  In the supercharger of the third embodiment, as shown in FIG. 4, the wall surface of the diffuser passage 57 of the variable capacity turbocharger 27 is provided with a water- and oil-repellent film 101 that is not hydrophilic and does not have lipophilicity. A water / oil repellent film 102 is provided on the wall surface of the intake passage 55 upstream of the diffuser passage 57, and a water / oil repellent film 103 is provided on the wall surface of the scroll passage 56 downstream of the diffuser passage 57.

  Therefore, when blow-by gas is sucked into the intake pipe 22 upstream of the compressor wheel 67 of the variable displacement turbocharger 27 due to intake negative pressure, the blow-by gas passes through the intake passage 55 together with the intake air to the compressor wheel 67. As a result, the oil contained in the blow-by gas tends to adhere to the wall surface of the diffuser passage 57. At this time, water and oil components contained in the blow-by gas are repelled by the water / oil repellent film 101 of the diffuser passage 57, and the oil component is prevented from adhering to the wall surface of the diffuser passage 57. In this case, even when the emulsion and water components contained in the blowby gas are mixed, the water and oil repellent film 101 prevents the water and oil components in the emulsion state from adhering.

  As described above, in the turbocharger according to the third embodiment, the compressor wheel 67 is rotatably provided on the intake passage 55 of the compressor housing 51, and the turbine wheel 68 is freely rotatable on the exhaust passage 61 of the turbine housing 58. The compressor wheel 67 and the turbine wheel 68 are connected to each other by a rotary shaft 65 so as to be integrally rotatable, and a diffuser passage 57 that communicates with the intake passage 55 and converts the dynamic pressure of fluid into static pressure is provided. A water / oil repellent film 101 is provided on the wall surface of the passage.

  Accordingly, when the blow-by gas of the diesel engine 11 is sucked into the intake pipe 22 through the PCV passage 36 due to the intake negative pressure and reaches the compressor wheel 67 through the intake passage 55 of the variable displacement turbocharger 27 together with the intake air, The contained moisture and oil components are repelled by the water / oil repellent film 101 of the diffuser passage 57, and by preventing the oil components from adhering to the wall surface of the diffuser passage 57, the oil adhering to the diffuser passage 57 is solidified. Can be suppressed.

  Further, in the supercharger of the present embodiment, the water / oil repellent film 102 is provided on the wall surface of the intake passage 55 upstream of the diffuser passage 57 and the water repellent / repellent surface is provided on the wall surface of the scroll passage 56 downstream of the diffuser passage 57. An oil film 103 is provided. Accordingly, the water and oil repellent films 102 and 103 can prevent the oil component contained in the blow-by gas from adhering to the wall surface of the intake passage 55 and the scroll passage 56.

  As described above, the supercharger according to the present invention suppresses solidification of oil attached to the diffuser passage of the compressor, and is suitable for use in any type of supercharger.

It is sectional drawing showing the supercharger which concerns on Example 1 of this invention. 1 is a schematic configuration diagram illustrating an internal combustion engine to which a supercharger according to a first embodiment is applied. It is sectional drawing showing the supercharger which concerns on Example 2 of this invention. It is sectional drawing showing the supercharger which concerns on Example 3 of this invention.

Explanation of symbols

11 Diesel engine (internal combustion engine)
17 Combustion chamber 22 Intake pipe 26 Exhaust pipe 27 Variable capacity turbocharger (supercharger)
36 PCV passage 37 PCV valve 38 Electronic control unit, ECU
51 Compressor housing (housing)
55 Intake passage 56 Scroll passage 57 Diffuser passage 58 Turbine housing (housing)
64 Center housing (housing)
65 Rotating shaft 67 Compressor wheel 68 Turbine wheel 81 Ceramic heater 82, 83 Oil repellent film 91, 92, 93 Hydrophilic film 101, 102, 103 Water / oil repellent film

Claims (5)

  A housing provided independently of an intake passage and an exhaust passage, a compressor wheel provided on the intake passage, a turbine wheel provided on the exhaust passage, a compressor wheel rotatably supported by the housing, and the In a turbocharger having a rotating shaft that connects a turbine wheel, a diffuser passage that communicates with the intake passage and converts a dynamic pressure of fluid into a static pressure is provided, and an oil component adhering to the wall surface of the diffuser passage is removed. A supercharger comprising a ceramic heater for incineration.   2. The supercharger according to claim 1, wherein the ceramic heater is configured such that the temperature of the fluid flowing through the intake passage is equal to or lower than a predetermined temperature, and the speed of the fluid is equal to or lower than a predetermined speed. And an oil component attached to the wall surface of the diffuser passage is incinerated.   3. The supercharger according to claim 1, wherein an oil repellent film or a hydrophilic film is provided on at least one passage wall surface on the upstream side or downstream side of the fluid in the diffuser passage. 4.   A housing provided independently of an intake passage and an exhaust passage, a compressor wheel provided on the intake passage, a turbine wheel provided on the exhaust passage, a compressor wheel rotatably supported by the housing, and the In a turbocharger having a rotating shaft that connects a turbine wheel, a diffuser passage that communicates with the intake passage and converts a dynamic pressure of fluid into a static pressure is provided, and a wall surface of the diffuser passage has hydrophilicity. A supercharger characterized in that a membrane is provided.   A housing provided independently of an intake passage and an exhaust passage, a compressor wheel provided on the intake passage, a turbine wheel provided on the exhaust passage, a compressor wheel rotatably supported by the housing, and the In a turbocharger having a rotating shaft that connects a turbine wheel, a diffuser passage that communicates with the intake passage and converts a dynamic pressure of fluid into a static pressure is provided, and a water repellency and an oil repellency are provided on a wall surface of the diffuser passage. A supercharger characterized by being provided with a water / oil repellent film.

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