JP2014105591A - Blow-by gas recirculation device in engine with supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent freezing due to moisture included in a blow-by gas in an outlet portion of a blow-by gas recirculation passage.SOLUTION: A supercharger 12 including a rotor 40 having a compressor wheel 42 disposed on an intake passage 14 of an engine 10, a turbine wheel 44 disposed on an exhaust passage 30 of the engine 10, and a rotating shaft 46 connecting the compressor wheel 42 and the turbine wheel 44, is loaded. A blow-by gas recirculation passage 50 for guiding a blow-by gas generated in the engine 10 to the intake passage 14 at an upstream side of the supercharger 12 is disposed. An outlet portion 54 of a blow-by gas introduction pipe 52 is disposed in a region receiving thermal influence of a shaft portion at a side of the compressor wheel 42, of the rotor 40 by heat of an exhaust gas.

Description

  The present invention relates to a blow-by gas recirculation device in a supercharged engine.

  Conventionally, a blowby gas recirculation device in a turbocharged engine mounted on a vehicle such as an automobile has a blowby gas recirculation passage that guides the blowby gas generated in the supercharged engine to an intake passage upstream of the supercharger. (See, for example, Patent Document 1). In Patent Document 1, the blow-by gas recirculation passage is disposed in a side surface where the exhaust system of the engine is disposed or in an area affected by the heat of the exhaust system in the vicinity thereof. Freezing due to moisture contained in the blow-by gas in the gas reflux passage is prevented.

Japanese Utility Model Publication No. 60-43110

Generally, the outlet part of the blow-by gas recirculation passage is cooled by low-temperature intake air. For this reason, there is a possibility that moisture contained in the blow-by gas freezes in the outlet portion of the blow-by gas recirculation passage at a low temperature such as traveling in a cold region. In a severe case, the ice lump grown in the outlet of the blow-by gas recirculation passage is sucked into the supercharger and is bitten by the compressor wheel, which may cause deformation or breakage of the impeller of the compressor wheel. In Patent Document 1, measures are taken to prevent freezing due to the influence of the external temperature in the middle of the pipeline of the blow-by gas recirculation passage, but cooling is performed by intake air in the vicinity of the outlet portion of the blow-by gas recirculation passage. This is not considered. In particular, since the outlet is connected to the intake passage upstream of the compressor of the turbocharger, it is separated from the exhaust system including the turbine of the turbocharger and actively uses the heat of the exhaust system. I can't.
The problem to be solved by the present invention is to prevent freezing due to moisture contained in the blow-by gas in the outlet of the blow-by gas recirculation passage.

Said subject is solved by each following invention.
According to a first aspect of the present invention, there is provided a rotor including a compressor wheel disposed on an intake passage of an engine, a turbine wheel disposed on an exhaust passage of the engine, and a rotating shaft connecting the compressor wheel and the turbine wheel. A blow-by gas recirculation device in a supercharged engine equipped with a blower and provided with a blow-by gas recirculation passage that guides blow-by gas generated in the engine to an intake passage upstream of the supercharger. An outlet portion of the blow-by gas recirculation passage is arranged in a region that is affected by heat of the compressor wheel side shaft portion of the rotor due to heat. According to this configuration, the outlet portion of the blow-by gas recirculation passage is heated by being affected by the heat of the compressor wheel side shaft portion of the rotor of the supercharger, so that it is included in the blow-by gas in the outlet portion of the blow-by gas recirculation passage. Freezing due to moisture can be prevented. As a result, it is possible to prevent the ice block from growing in the outlet part of the blow-by gas recirculation passage, and to prevent the impeller deformation or breakage of the compressor wheel due to the ice block being caught in the compressor wheel of the turbocharger rotor. .

  According to a second invention, in the first invention, the rotating shaft of the rotor of the supercharger is provided with a heat conducting member having good heat conductivity. With this configuration, the heat of the exhaust gas can be efficiently conducted from the turbine wheel side to the compressor wheel side by the heat conduction member having good heat conductivity provided on the rotating shaft of the rotor of the supercharger. For this reason, the heating efficiency of the exit part of a blowby gas recirculation passage can be improved. Moreover, the area | region which receives the heat influence of the compressor wheel side axial part of a rotor by the heat | fever of exhaust gas can be expanded.

  According to a third invention, in the first or second invention, an extension portion extending toward the outlet portion side of the blow-by gas recirculation passage is formed in the compressor wheel side shaft portion of the rotor of the supercharger. According to this configuration, the extension part formed in the compressor wheel side shaft part of the rotor of the turbocharger allows the region affected by the heat of the exhaust gas from the compressor wheel side shaft part to be affected by the heat of the exhaust gas. Can be close.

  In a fourth aspect based on the second aspect, the heat conducting member is a heat pipe. According to this configuration, the heat pipe can efficiently conduct the heat of the exhaust gas from the turbine wheel side to the compressor wheel side.

  In a fifth aspect based on the second aspect, the heat conducting member is made of a high thermal conductivity material having a high thermal conductivity. According to this configuration, the heat of the exhaust gas can be efficiently conducted from the turbine wheel side to the compressor wheel side by the heat conducting member formed of a high thermal conductivity material having high thermal conductivity.

It is a block diagram which shows the blowby gas recirculation apparatus in the engine with a supercharger concerning Embodiment 1. FIG. It is sectional drawing which shows the peripheral part of a supercharger. It is sectional drawing which shows the peripheral part of the supercharger concerning Embodiment 2. It is sectional drawing which shows the peripheral part of the supercharger concerning Embodiment 3. It is sectional drawing which shows the peripheral part of the supercharger concerning Embodiment 4. It is sectional drawing which shows the peripheral part of the supercharger concerning Embodiment 5. It is sectional drawing which shows the peripheral part of the supercharger concerning Embodiment 6.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[Embodiment 1]
Embodiment 1 will be described. For convenience of explanation, FIG. 1 is a block diagram showing a blow-by gas recirculation device in a supercharged engine.
The outline of the supercharged engine will be described. As shown in FIG. 1, a turbocharger, that is, a supercharger 12 is mounted on an engine (internal combustion engine) 10. The intake passage 14 of the engine 10 includes an air cleaner 15, an intake pipe 16, a compressor housing 18 of the supercharger 12, a connection pipe 20, a surge tank 21, a throttle body 24 of the throttle device 23, arranged from the upstream side to the downstream side. The intake manifold 26 and the intake port 27 of the engine 10 are configured. The throttle device 23 includes a throttle valve 25 that adjusts the amount of intake air flowing through the throttle body 24. The intake manifold 26 is provided with a fuel injection valve 28. The exhaust passage 30 of the engine 10 includes an exhaust port 31, an exhaust manifold 32, a turbine housing 34 of the supercharger 12, a connection pipe 36, and an exhaust pipe (not shown) arranged from the upstream side toward the downstream side. Etc.

  The supercharger 12 includes a housing 17 and a rotor 40. The housing 17 includes a compressor housing 18, a turbine housing 34, and a center housing 38. The compressor housing 18 is disposed on the intake passage 14, that is, between the intake pipe 16 and the connection pipe 20. The turbine housing 34 is disposed on the exhaust passage 30, that is, between the exhaust manifold 32 and the connection pipe 36. The center housing 38 connects the compressor housing 18 and the turbine housing 34. The rotor 40 is rotatably accommodated in the housing 17. The rotor 40 includes a compressor wheel 42, a turbine wheel 44, and a rotating shaft 46. The compressor wheel 42 has a large number of impellers 42 a on the outer peripheral portion and is disposed in the compressor housing 18. Further, the turbine wheel 44 has a large number of impellers 44 a on the outer peripheral portion and is disposed in the turbine housing 34. The rotation shaft 46 connects the compressor wheel 42 and the turbine wheel 44 and is rotatably supported in the center housing 38. Although not shown, the supercharger 12 includes a lubricating oil circulation mechanism that circulates lubricating oil in the bearing portion of the rotating shaft 46 with respect to the center housing 38.

  The air introduced into the intake passage 14 from the air cleaner 15, that is, the intake air is pressurized by the compressor wheel 42 of the supercharger 12, the intake air amount is adjusted by the throttle valve 25 of the throttle device 23, and then from the fuel injection valve 28. It is sucked into the combustion chamber 11 of the engine 10 together with the injected fuel. Further, the exhaust gas discharged from the combustion chamber 11 to the exhaust passage 30 is discharged to the outside after driving the turbine wheel 44 of the supercharger 12.

  A blow-by gas recirculation device in the supercharged engine will be described. Blow-by gas generated in the engine 10 accumulates in the cylinder head cover 48 and a crankcase (not shown). The blow-by gas is recirculated to the intake passage 14 via the blow-by gas recirculation passage 50. The blow-by gas recirculation passage 50 has one end (inlet side end) connected to the cylinder head cover 48 and the other end (outlet side end) connected to the suction pipe 16. Note that the inlet side end of the blowby gas recirculation passage 50 may be connected to a crankcase instead of the cylinder head cover 48.

Next, the main part of the blow-by gas recirculation device in the supercharged engine will be described. FIG. 2 is a sectional view showing a peripheral portion of the supercharger.
As shown in FIG. 2, the suction pipe 16 is provided with a straight tubular blow-by gas introduction pipe 52 that penetrates from the radial direction, that is, from above toward the center of the pipe. The blowby gas introduction pipe 52 constitutes an outlet side passage portion of the blowby gas recirculation passage 50. Further, an outlet 53 that opens toward the downstream side (right side in FIG. 2) of the intake passage 14 of the suction pipe 16 is formed at the distal end (lower end) of the blow-by gas introduction pipe 52. A peripheral portion of the outlet 53 of the blow-by gas introduction pipe 52 is referred to as an outlet portion 54. Note that the vertical direction in FIG. 2 corresponds to the vertical direction when the supercharger 12 is mounted on the engine 10.

  In the supercharger 12, the rotation shaft 46 of the rotor 40 is formed in a solid shaft shape. The rotary shaft 46 is inserted through a shaft hole 55 formed in the turbine wheel 44 in a penetrating manner and is integrally coupled to the turbine wheel 44. The rotating shaft 46 is inserted through a shaft hole 56 formed in the compressor wheel 42 in a penetrating manner and is integrally coupled to the compressor wheel 42. Further, a nut 58 for tightening the compressor wheel 42 is screwed to a screw shaft portion 47 formed at the tip portion of the rotating shaft 46. The rotating shaft 46 is rotatably supported by the center housing 38 via a bearing 60. In addition, a seal member 62 is provided between the compressor housing 18 and the rotary shaft 46 to seal between the two.

  A round shaft-like extending shaft portion 64 having an outer diameter smaller than the valley diameter of the screw shaft portion 47 is integrally formed concentrically with the tip surface of the screw shaft portion 47 of the rotating shaft 46. The distal end portion of the extending shaft portion 64 is close to the outlet 53 of the outlet portion 54 of the blow-by gas introduction pipe 52 in an opposing manner. The rotating shaft 46 having the extending shaft portion 64 is made of a high thermal conductivity material having a high thermal conductivity. As the high thermal conductivity material having a high thermal conductivity, a metal material having a high thermal conductivity, such as a copper-based alloy material, can be used as compared with a rotating shaft formed of a general steel material. Therefore, the rotating shaft 46 is a heat conducting member having a good thermal conductivity, and generally includes a heat conducting member having a good thermal conductivity. The extension shaft portion 64 corresponds to an “extension portion” in the present specification. Further, the shaft portion (including the screw shaft portion 47 and the extending shaft portion 64) on the compressor wheel 42 side of the rotating shaft 46 corresponds to the “compressor wheel side shaft portion” in this specification.

  Further, the heat of the exhaust gas of the engine 10 is transmitted from the turbine wheel 44 side to the compressor wheel 42 side shaft portion via the rotating shaft 46. For this reason, the compressor wheel 42 side shaft portion (including the extended shaft portion 64) of the rotor 40 is affected by the heat of the exhaust gas. An outlet portion 54 of the blow-by gas introduction pipe 52 is disposed in the region R that is affected by the heat.

  According to the blow-by gas recirculation device in the supercharger-equipped engine, in the region R affected by the heat of the compressor wheel 42 side shaft portion (including the extended shaft portion 64) of the rotor 40 of the supercharger 12 due to the heat of the exhaust gas. The outlet portion 54 of the blow-by gas introduction pipe 52 is disposed. Accordingly, the outlet portion 54 of the blow-by gas introduction pipe 52 is heated under the influence of the heat of the compressor wheel 42 side shaft portion (specifically, the extension shaft portion 64) of the rotor 40 of the supercharger 12, thereby introducing the blow-by gas. Freezing due to moisture contained in the blow-by gas in the outlet portion 54 of the pipe 52 can be prevented. Eventually, ice block growth in the outlet portion 54 of the blow-by gas introduction pipe 52 is prevented, and deformation or breakage of the impeller of the compressor wheel 42 caused by the ice block being caught in the compressor wheel 42 of the rotor 40 of the supercharger 12. Etc. can be prevented. When the engine 10 is started, it is preferable to reduce the circulation amount of the lubricating oil by the lubricating oil circulation mechanism of the supercharger 12 and suppress the cooling of the rotating shaft 46 by the lubricating oil.

  Further, since the tip end portion of the extending shaft portion 64 of the rotating shaft 46 is close to the outlet portion 54 of the blow-by gas introduction pipe 52, the heating efficiency of the outlet portion 54 of the blow-by gas introduction pipe 52 can be improved. it can. Further, the tip end portion of the extending shaft portion 64 of the rotating shaft 46 is close to the outlet 53 of the outlet portion 54 of the blow-by gas introduction pipe 52 so as to oppose the outlet portion 54 of the blow-by gas introduction pipe 52. The mouth edge of the outlet 53 can be efficiently heated.

  Further, the heat of the exhaust gas is transferred to the turbine wheel 44 side by a rotating shaft 46 that is generally provided with a heat conductive member having a high heat conductivity formed of a high heat conductivity material of the rotor 40 of the supercharger 12. Can be efficiently conducted to the compressor wheel 42 side (specifically, the extended shaft portion 64). For this reason, the heating efficiency of the exit part 54 of the blow-by gas introduction pipe 52 can be improved. This is effective in expanding the region R that is affected by the heat of the compressor wheel 42 side shaft portion of the rotor 40 due to the heat of the exhaust gas.

  Further, the extended shaft portion 64 formed on the compressor wheel 42 side shaft portion of the rotor 40 of the supercharger 12 causes the region R that is affected by the heat of the exhaust gas from the compressor wheel 42 side shaft portion of the rotor 40 to blow-by gas. It can be brought close to the outlet 54 of the introduction pipe 52.

  In addition, you may form the rotating shaft 46 with a general steel material. Further, the extending shaft portion 64 of the rotating shaft 46 may be formed by coupling a shaft member separate from the rotating shaft 46 to the rotating shaft 46. In this case, the shape, size, material, and the like of the extended shaft portion (shaft member) 64 can be appropriately changed. Further, the extending shaft portion 64 may be formed on the compressor wheel 42 itself instead of the rotating shaft 46. In this case, the rotating shaft 46 may be integrally coupled without penetrating the compressor wheel 42. Further, the rotating shaft 46 may be integrally coupled without penetrating the turbine wheel 44. Further, the outlet 53 of the blow-by gas introduction pipe 52 may be opened downward. In this case, the extended shaft portion 64 may be disposed near the outlet 53 of the blow-by gas introduction pipe 52.

[Embodiment 2]
A second embodiment will be described. Since the present embodiment and the subsequent embodiments are modifications to the first embodiment, the changed portions will be described, and duplicate descriptions will be omitted. FIG. 3 is a cross-sectional view showing a peripheral portion of the supercharger.
In this embodiment, as shown in FIG. 3, the extending shaft portion 64 of the rotating shaft 46 in the first embodiment (see FIG. 2) is omitted. In addition, an extension pipe portion 66 extending toward the downstream side (right side in FIG. 2) of the intake passage 14 of the suction pipe 16 is formed at the distal end portion (lower end portion) of the blow-by gas introduction pipe 52. An outlet 67 is formed at the distal end portion of the extending pipe portion 66, and the peripheral portion of the outlet 67 is an outlet portion 68. The outlet portion 68 of the extending tube portion 66 is close to the tip surface of the screw shaft portion 47 of the rotating shaft 46 so as to face each other. As a result, the outlet portion 68 of the extended pipe portion 66 of the blow-by gas introduction pipe 52 is disposed in a region R that is affected by the heat of the exhaust gas on the compressor wheel 42 side shaft portion of the rotor 40. The extension pipe portion 66 corresponds to “an extension portion extending toward the compressor wheel 42 side shaft portion of the rotor 40”.

[Embodiment 3]
A third embodiment will be described. This embodiment is a modification of the first embodiment. FIG. 4 is a sectional view showing a peripheral portion of the supercharger.
In the present embodiment, as shown in FIG. 4, the rotation shaft 46 in the first embodiment (see FIG. 2) is changed to a rotation shaft 70 formed in a hollow shaft shape. The hollow portion 72 of the rotating shaft 70 is closed by a closing portion 73 at the tip end portion of the extending shaft portion 64. Thereby, exhaust gas can be flowed in into the hollow part 72 of the rotating shaft 70, and the rotating shaft 70 can be heated with the heat | fever of exhaust gas. In addition, the axial length, the hole diameter, etc. of the hollow part 72 of the rotating shaft 70 can be changed as appropriate.

[Embodiment 4]
A fourth embodiment will be described. This embodiment is a modification of the second embodiment. FIG. 5 is a cross-sectional view showing a peripheral portion of the supercharger.
In the present embodiment, as shown in FIG. 5, the rotation shaft 46 in the second embodiment (see FIG. 3) is changed to a rotation shaft 75 formed in a hollow shaft shape. The hollow portion 77 of the rotating shaft 75 is closed by a closing portion 78 at the distal end portion of the screw shaft portion 47. Thereby, exhaust gas can be flowed in into the hollow part 77 of the rotating shaft 75, and the rotating shaft 75 can be heated with the heat | fever of exhaust gas. In addition, the axial length, the hole diameter, etc. of the hollow part 77 of the rotating shaft 75 can be suitably changed.

[Embodiment 5]
A fifth embodiment will be described. This embodiment is a modification of the fourth embodiment. FIG. 6 is a cross-sectional view showing a peripheral portion of the supercharger.
In the present embodiment, as shown in FIG. 6, the closing portion 76 of the rotating shaft 75 in the fourth embodiment (see FIG. 5) is opened and the diameter of the hollow portion 77 is enlarged. A round bar-shaped heat pipe 80 is integrally incorporated in the hollow portion 77 of the rotating shaft 75. The heat pipe 80 includes a round bar-like tube body 81 formed of a high thermal conductivity material such as aluminum or copper, and evaporates and condenses in a closed space in the tube body 81 with a wick having a capillary action in a narrow temperature range. The working fluid is enclosed. In the heat pipe 80, an end portion on the turbine wheel 44 side is a heat absorbing portion 80a, and an end portion on the compressor wheel 42 side is a heat radiating portion 80b. The heat pipe 80 circulates the working fluid between the heat absorbing portion 80a and the heat radiating portion 80b due to the temperature difference between the heat absorbing portion 80a and the heat radiating portion 80b, and the heat fluid circulates from the heat absorbing portion 80a to the heat radiating portion 80b. It moves heat. Therefore, the heat pipe 80 can efficiently conduct the heat of the exhaust gas from the turbine wheel 44 side to the compressor wheel 42 side. The heat pipe 80 corresponds to a “thermal conductive member having good thermal conductivity” in this specification. Moreover, you may form the rotating shaft 75 with a general steel material. In addition, the heat pipe 80 itself can be used as the rotation axis.

[Embodiment 6]
A sixth embodiment will be described. This embodiment is a modification of the third embodiment. FIG. 7 is a cross-sectional view showing a peripheral portion of the supercharger.
In the present embodiment, as shown in FIG. 7, the rotary shaft 70 in the third embodiment (see FIG. 4) is used as the outer shaft 70 (the same reference numeral is assigned to the rotary shaft), and the inner shaft 83 is integrated in the hollow portion 72. Is incorporated. That is, it is changed to a rotating shaft (indicated by reference numeral 84) having an inner / outer double shaft structure. The outer shaft 70 is made of a general steel material. Further, the inner shaft 83 is formed of a high thermal conductivity material having a high thermal conductivity, for example, a copper-based alloy material, and is a thermal conductive member having a good thermal conductivity. Therefore, the heat of the exhaust gas is efficiently conducted from the turbine wheel 44 side to the compressor wheel 42 side by the inner shaft 83 which is a heat conduction member having a high heat conductivity and made of a high heat conductivity material. Can do. The closed portion 73 of the outer shaft 70 may be omitted and the hollow portion 72 may be opened. Further, the inner shaft 83 may be formed of a general steel material, and the outer shaft 86 may be formed of a high thermal conductivity material having a high thermal conductivity.

  The present invention is not limited to the above-described embodiment, and modifications can be made without departing from the gist of the present invention. The technical elements described in the above embodiments exhibit technical usefulness alone or in various combinations. For example, in the second embodiment (see FIG. 3), the blow-by gas introduction pipe in the first embodiment (see FIG. 2) is in the region R that is affected by the heat of the compressor wheel 42 side shaft portion of the rotor 40 of the supercharger 12. The arrangement position of the blow-by gas introduction pipe 52 may be changed so that the outlet part 54 of the 52 is arranged. Moreover, you may provide the extending shaft part 64 of the rotating shaft 46 in the said Embodiment 1 (refer FIG. 2), and the extending pipe part 66 of the blowby gas introduction pipe 52 in the said Embodiment 2 (refer FIG. 3). . Moreover, you may arrange | position partially or disperse | distributed the heat conductive member with high heat conductivity formed of the high heat conductivity material with high heat conductivity to a rotating shaft.

DESCRIPTION OF SYMBOLS 10 ... Engine 12 ... Supercharger 14 ... Intake passage 30 ... Exhaust passage 40 ... Rotor 42 ... Compressor wheel 44 ... Turbine wheel 46 ... Rotating shaft (heat conduction member)
54 ... Exit part 64 ... Extension shaft part 66 ... Extension pipe part 68 ... Exit part 70 ... Rotation shaft 75 ... Rotation shaft 50 ... Blow-by gas recirculation passage 80 ... Heat pipe (heat conduction member)
84 ... Rotating shaft 83 ... Inner shaft (heat conducting member)
86 ... Outer shaft R ... Area

Claims (5)

A turbocharger including a rotor having a compressor wheel disposed on an intake passage of the engine, a turbine wheel disposed on an exhaust passage of the engine, and a rotating shaft connecting the compressor wheel and the turbine wheel is mounted. A blowby gas recirculation device in a supercharged engine provided with a blowby gas recirculation passage for guiding blowby gas generated in the engine to an intake passage upstream of the supercharger,
A blow-by gas recirculation device in a supercharged engine, wherein an outlet of the blow-by gas recirculation passage is disposed in a region that is affected by heat of exhaust gas on a compressor wheel side shaft portion of the rotor. A blowby gas recirculation device in a supercharged engine according to claim 1,
A blow-by gas recirculation device in an engine with a supercharger, characterized in that a heat conduction member having good heat conductivity is provided on a rotating shaft of a rotor of the supercharger. A blowby gas recirculation device in a supercharged engine according to claim 1 or 2,
The blow-by gas recirculation apparatus in an engine with a supercharger, wherein an extension portion extending toward an outlet side of the blow-by gas recirculation passage is formed in a compressor wheel side shaft portion of the rotor of the supercharger. It is a blowby gas recirculation apparatus in the engine with a supercharger according to claim 2,
The blow-by gas recirculation apparatus in a supercharged engine, wherein the heat conducting member is a heat pipe. It is a blowby gas recirculation apparatus in the engine with a supercharger according to claim 2,
The blow-by gas recirculation device in an engine with a supercharger, wherein the heat conducting member is made of a high thermal conductivity material having high thermal conductivity.

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