JP2018031261A - Compressor housing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compressor housing capable of suppressing the adhesion of oil in blow-by gas with a simple structure.SOLUTION: A compressor housing 1 is formed with: an impeller chamber 2 for rotatably storing an impeller 5; an intake flow path 7 which extends along an axis C of the impeller 5 and leads intake air to a front edge portion 53 of the impeller 5; and a breather flow path 82 which leads blow-by gas into the intake flow path 7. The intake flow path 7 is equipped with a small-diameter portion 71 which communicates into the impeller chamber 2 and has an inner diameter corresponding to an outer diameter of the front edge portion 53 of the impeller 5, and a large-diameter portion 75 which is connected at an upstream end opening 72 of the small-diameter portion 71 through an annular shoulder portion 73 and has an inner diameter larger than the small-diameter portion 71. At a part connecting the large-diameter portion 75 and the shoulder portion 73, a lowest bottom portion 76 of the intake flow path 7 in a mounting posture of the compressor housing 1 is formed, and a drain hole 61 is formed on the bottom portion 76.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a compressor housing. More specifically, the present invention relates to a structure of a compressor housing including an impeller chamber, an intake passage, and a breather passage.

  In a supercharging system for an internal combustion engine, a compressor provided in an intake passage of the internal combustion engine is rotationally driven by using exhaust energy or electric energy of the internal combustion engine, thereby pressurizing intake air supplied to the internal combustion engine. The compressor includes a compressor impeller, an impeller chamber that houses the compressor impeller, and a compressor housing in which an intake passage that guides intake air to the impeller chamber is formed.

  By the way, the mixture or exhaust gas (hereinafter referred to as “blow-by gas”) that has flowed into the crankcase of the internal combustion engine may be suppressed by returning to the intake passage through the breather pipe. Many. For example, as shown in Patent Document 1, in a supercharging system including a compressor as described above, blow-by gas often recirculates upstream of the compressor impeller in the intake passage.

JP 2005-226505 A

  Blow-by gas contains mist-like oil. Therefore, intake air containing oil is introduced into the impeller chamber, but during high load operation of the internal combustion engine, the impeller chamber is at a high pressure and high temperature, so this oil decelerates the exhaust discharged from the impeller chamber and the impeller chamber. It accumulates in the diffuser chamber and adheres to it, and the performance of the compressor may deteriorate.

  As a technique for suppressing such oil sticking, a technique is used to recirculate blowby gas from which oil has been separated by using a separation device into the intake flow path, or supercharging to the extent that oil does not stick in the impeller chamber or diffuser chamber. Techniques for performing control to suppress pressure have been proposed. However, if the oil in the blow-by gas is to be completely separated, the separation device may be expensive. Moreover, if the control which suppresses a supercharging pressure is performed, the original performance of a compressor cannot fully be utilized.

  An object of this invention is to provide the compressor housing which can suppress adhesion of the oil in blow-by gas with a simple structure.

  (1) A compressor housing (for example, compressor housings 1, 1A, 1B, 1C described later) is a compressor (for example, a compressor 92C described later) that pressurizes the intake air of the internal combustion engine using an impeller (for example, compressor impeller 5 described later). ). The compressor housing includes an impeller chamber (for example, an impeller chamber 2 described later) that rotatably accommodates the impeller, and a front edge portion of the impeller that extends along an axis (for example, an axis C described later) of the impeller. For example, it is connected to an intake passage (for example, an after-mentioned intake passage 7) for guiding intake air to a later-described front edge portion 53) and a breather pipe (for example, a later-described breather pipe 96) through which blow-by gas of the internal combustion engine flows. A breather passage (for example, breather passages 82 and 82C described later) for guiding the blow-by gas into the intake passage, and the intake passage communicates with the impeller chamber and has a leading edge of the impeller. A small-diameter portion (for example, a small-diameter portion 71 described later) having an inner diameter corresponding to the outer diameter of the portion, and an annular shoulder (for example, an upstream end 72 described later) A large-diameter portion (for example, a large-diameter portion 75 described later) that is connected via a shoulder portion 73 described later and has a larger inner diameter than the small-diameter portion, and connects the large-diameter portion and the shoulder portion. The bottom portion (for example, a bottom portion 76 to be described later) of the intake passage in the mounting posture of the compressor housing is formed in the portion to be drained, and drain holes (for example, drain holes 61, 61B, to be described later) are formed in the bottom portion. 61C) is formed.

  (2) In this case, the inner wall surface of the shoulder portion becomes smaller as an angle (for example, an angle θ described later) formed by a tangent in the cross section including the axis and the axis decreases from the radially inner side to the outer side of the impeller. It is preferable to provide a curved surface.

  (3) In this case, it is preferable that the bottom portion is concave upward in the mounting posture, and the drain hole is formed at the bottom of the bottom portion.

  (4) In this case, the compressor housing is provided around the impeller chamber, and a diffuser chamber (for example, a later-described diffuser chamber 3) that decelerates the intake air discharged from the impeller chamber in the radial direction of the impeller; An annular scroll passage (for example, a scroll passage 4 described later) provided around the diffuser chamber and through which intake air discharged from the diffuser chamber in the radial direction of the impeller flows, and the drain hole It is preferable that the through hole communicates the bottom portion and an introduction portion (for example, an introduction portion 41 to be described later) provided in a portion of the scroll flow path that is lower than the bottom portion in the mounting posture.

  (5) In this case, the compressor housing further includes a valve body (for example, a valve body 631 described later) that connects or blocks communication between the bottom portion and the inside of the scroll flow path via the through hole, The valve body is preferably closed when the internal combustion engine is in a high load operation, and is opened when the internal combustion engine is in a low load operation.

  (6) In this case, it is preferable that the compressor housing further includes a cooling water passage (for example, a water jacket 65 described later) that flows in the vicinity of the through hole.

  (7) In this case, the opening on the introduction portion side (for example, a drain opening 42 described later) of the through hole is inclined vertically downward in the mounting posture, and the introduction portion includes the opening of the opening. It is preferable that a shaft body (for example, a shaft body 632 described later) that pivotably supports the valve body on the vertically upper side is provided.

  (8) In this case, the compressor housing closes the valve body when the internal combustion engine is in a high load operation, and opens / closes to open the valve body when the internal combustion engine is in a low load operation (for example, an electromagnetic actuator described later) 66 and controller 67).

  (9) In this case, a breather recirculation pipe connection (for example, a later-described) connected to a breather recirculation pipe (for example, a later-described breather recirculation pipe 99) communicated with the crankcase of the internal combustion engine is connected to the outside of the compressor housing. It is preferable that a breather reflux pipe connection portion 83) is formed, and the drain hole is a through hole that communicates the bottom portion and the breather reflux pipe connection portion.

  (10) In this case, a breather pipe connection part (for example, a pipe connection part 81C described later) to which the breather pipe is connected is formed outside the compressor housing, and the drain hole is formed between the bottom part and the breather pipe. Preferably, the through hole communicates with the connection portion, and the breather flow path is a flow path formed by the through hole.

  (1) In the compressor housing of the present invention, an impeller chamber, an intake passage that guides intake air to the front edge of the impeller, and a breather passage that guides blow-by gas into the intake passage are formed. In addition, the intake flow path is connected to the small-diameter portion that communicates with the impeller chamber and has an inner diameter corresponding to the outer diameter of the front edge portion of the impeller, and is connected to the small-diameter portion via an annular shoulder at the upstream end of the small-diameter portion. And a large-diameter portion having a larger inner diameter. When the impeller rotates at high speed, a swirling flow in the same direction as the impeller rotation direction is generated in the intake passage. For this reason, the blow-by gas introduced into the intake passage through the breather passage is separated into a relatively light gas component and heavy oil by this swirling flow, and the oil circulates on the inner wall surface of the annular shoulder portion. Therefore, it is possible to suppress the oil in the blow-by gas from entering the impeller chamber. Further, in the compressor housing of the present invention, the lowest bottom portion of the intake flow path is formed in the mounting posture at a portion connecting the large diameter portion and the shoulder portion, and a drain hole is formed in the bottom portion. Therefore, the oil separated from the blow-by gas using the inner wall surface of the shoulder when the impeller is rotated as described above can be stored in the bottom when the impeller rotates at a high speed, for example. The oil stored in the bottom can be returned to other parts other than the impeller chamber through the drain hole at an appropriate timing, for example, when the impeller rotates at a low speed. Therefore, according to the present invention, since the oil in the blow-by gas can be prevented from entering the impeller chamber at both the low speed rotation and the high speed rotation of the impeller, the oil is fixed in the impeller chamber and the diffuser chamber downstream thereof. Can also be suppressed.

  (2) According to the compressor housing of the present invention, the inner wall surface of the shoulder portion has a curved surface in which the angle formed between the tangent line and the axis line in the cross section including the axis line becomes smaller as it goes from the radially inner side to the outer side of the impeller. In other words, the inner wall surface of the shoulder has a bowl shape. As a result, when a swirl flow is generated in the intake flow path, relatively heavy oil contained in the blow-by gas is moved to the radially outer side of the curved surface of the shoulder portion, that is, away from the small diameter portion by centrifugal force. Since it can push, the penetration | invasion into the impeller chamber of the oil in blow-by gas can further be suppressed.

  (3) According to the compressor housing of the present invention, the bottom portion is recessed upward in the mounting posture, and the drain hole is formed at the bottom of the bottom portion. As a result, even if a large amount of oil is separated at the shoulder during high-speed rotation of the impeller, this large amount of oil can be stored at the bottom without flowing out into the impeller chamber during low-speed rotation of the impeller. . Further, the oil accumulated at the bottom can be refluxed to other parts than the impeller chamber through the drain hole.

  (4) According to the compressor housing of the present invention, the diffuser chamber is formed around the impeller chamber, the annular scroll passage is formed around the diffuser chamber, and the drain hole is formed between the bottom of the intake passage and the scroll passage. In the mounting posture, a through-hole that communicates with an introduction portion provided at a portion lower than the bottom portion is used. Since an impeller is provided in the impeller chamber, when oil flows into the impeller chamber, the oil adheres to the impeller and the performance of the compressor may be deteriorated. Further, since the diffuser chamber is narrower than the scroll flow path, the diffuser chamber is easily fixed when oil flows in, and the performance of the compressor is greatly deteriorated due to the fixed oil. In the present invention, the bottom portion of the intake passage and the introduction portion of the scroll passage are connected by a through hole, so that the oil accumulated in the bottom portion flows into the impeller chamber and the diffuser chamber having a low oil adhesion toughness as described above. In this case, the oil can be introduced into the scroll passage having a higher toughness of oil. Further, by connecting the bottom portion of the intake flow channel and the introduction portion lower than the bottom portion of the scroll flow channel, the oil accumulated in the bottom portion can be introduced into the scroll flow channel using its own weight.

  (5) The compressor housing of the present invention is a valve body that connects or blocks communication between the bottom and the inside of the scroll flow path, and is closed when the internal combustion engine is in a high load operation and opened when the internal combustion engine is in a low load operation. Further prepare. Therefore, during high-load operation of an internal combustion engine where the inside of the scroll passage is relatively hot, the oil in the blow-by gas is centrifuged at the shoulder by the swirling flow generated in the intake passage, and the inside of the scroll passage is compared. At the time of low load operation of the internal combustion engine that is at a low temperature, oil that has been centrifuged during high load operation can be recirculated into the scroll passage through the drain hole. As a result, the oil in the blow-by gas can be recirculated into the intake air without being exposed to a high temperature.

  (6) The compressor housing of this invention is further equipped with the cooling water flow path which flows through the vicinity of a through-hole. Thereby, since the oil before reaching the scroll flow path through the through hole can be cooled by the cooling water, the oil sticking in the scroll flow path can be suppressed.

  (7) According to the compressor housing of the present invention, the opening on the introduction portion side of the through hole is inclined vertically downward in the mounting posture, and is a shaft body provided on the vertically upper side of the inclined opening. The valve body is pivotally supported. Thereby, when the internal combustion engine is operated at a low load, the inside of the scroll passage is at a relatively low pressure, so that the valve body can be opened by its own weight. In addition, when the internal combustion engine is operated at a high load, the scroll passage has a relatively high pressure, and the valve body can be closed using the pressure in the scroll passage. That is, according to the compressor housing of the present invention, the valve body can be opened and closed at an appropriate timing according to the operating state of the internal combustion engine without using an electromagnetic actuator.

  (8) The compressor housing according to the present invention further includes opening / closing means for closing the valve body when the internal combustion engine is in a high load operation and opening the valve body during a low load operation. Thus, even when the valve body is difficult to open and close due to the viscosity of the oil, the valve body can be opened and closed at an appropriate timing according to the operating state of the internal combustion engine.

  (9) According to the compressor housing of the present invention, a breather recirculation pipe connecting portion to which a breather recirculation pipe communicating with the crankcase is connected is formed on the outer side, and the drain hole is connected to the bottom of the intake passage and the breather recirculation pipe. A through-hole communicating with the part is used. Thereby, the oil accumulated at the bottom can be recirculated into the crankcase via the breather recirculation pipe.

  (10) According to the compressor housing of the present invention, a breather pipe connecting portion to which a breather pipe is connected is formed on the outer side, and the drain hole is a through hole that communicates the bottom of the intake passage and the breather pipe connecting portion. The breather channel is a channel formed by this through hole. As a result, according to the compressor housing of the present invention, the oil in the blow-by gas supplied from the bottom of the intake passage is separated by the swirling flow generated in the intake passage as described above, and then again from the bottom, the breather It is recirculated into the crankcase via piping. Therefore, according to the present invention, the oil in the blow-by gas can be recirculated into the crankcase with a simple configuration without entering the impeller chamber.

1 is a plan view of an engine room of a vehicle to which a compressor housing according to a first embodiment of the present invention is applied. It is sectional drawing of the compressor housing which concerns on the said embodiment. It is sectional drawing which shows the structure of the compressor housing at the time of high load driving | operation. It is sectional drawing which shows the structure of the compressor housing at the time of low load operation. It is sectional drawing of the compressor housing which concerns on 2nd Embodiment of this invention. It is sectional drawing of the compressor housing which concerns on 3rd Embodiment of this invention. It is sectional drawing of the compressor housing which concerns on 4th Embodiment of this invention.

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of an engine room ER of a vehicle equipped with a supercharging system S for an internal combustion engine (hereinafter referred to as “engine”). FIG. 1 shows devices that mainly constitute the intake system of the supercharging system S among various devices provided in the engine room ER. That is, FIG. 1 is a view of the supercharging system S in a state of being mounted in a predetermined mounting posture in the engine room ER as viewed from above in the vertical direction.

  The supercharging system S includes an air cleaner box 91 that purifies outside air, an exhaust turbine that converts exhaust energy into mechanical energy of a rotating shaft, and a compressor 92C that pressurizes intake air using a compressor impeller that will be described later connected to the rotating shaft. A turbocharger 92, an intake pipe 93 connecting the air cleaner box 91 and the compressor 92C, an air flow meter 94 for detecting the flow rate of intake air flowing through the intake pipe 93, a compressor 92C and a crankshaft of an engine (not shown). And a breather pipe 96 to be connected. FIG. 1 shows a state in which the exhaust turbine of the supercharger 92 is covered with a plate-like cover member 97.

  The intake pipe 93 extends substantially horizontally in its mounting posture, and connects the air cleaner box 91 and an after-mentioned intake duct formed in the compressor housing 1 constituting the main body of the compressor 92C. The main flow of the intake air purified by the air cleaner box 91 flows into the compressor housing 1 in the direction indicated by the arrow 98a in FIG. The air flow meter 94 is provided in a position closer to the air cleaner box 91 than the compressor housing 1 in the intake pipe 93.

  The breather pipe 96 connects a crankcase (not shown) and a later-described breather duct formed in the compressor housing 1. As a result, blow-by gas flows into the compressor housing 1 in a direction substantially perpendicular to the main flow of the intake air indicated by the arrow 98a, as indicated by the arrow 98c in FIG.

  FIG. 2 is a cross-sectional view of the compressor housing 1. More specifically, FIG. 2 is a cross-sectional view including the axis C of the compressor impeller 5 housed in the compressor housing 1. FIG. 2 is a view of the compressor housing 1 in the mounting posture as viewed from the side. That is, the vertical direction in FIG. 2 is equal to the vertical direction of the compressor housing 1 in the mounting posture. Further, the axis C of the compressor impeller 5 is substantially horizontal in the mounting posture.

  The compressor housing 1 is connected to an impeller chamber 2 that rotatably accommodates a compressor impeller 5 around a rotation axis R, a diffuser chamber 3, a scroll flow path 4, and an intake pipe 93 (see FIG. 1), so that intake air is taken in. An intake duct 6 to be introduced into the impeller chamber 2 and a breather pipe 96 (see FIG. 1) are connected, and a breather duct 8 for introducing a breather gas into the intake duct 6 is provided.

  The compressor impeller 5 includes a wheel 51 connected to a rotation shaft R that is driven to rotate by an exhaust turbine, and a plurality of blades 52 provided on a conical hub surface of the wheel 51. The blades 52 are provided at equal intervals along the circumferential direction on the hub surface of the wheel 51. Each blade 52 has a plate shape extending at a predetermined angular distribution from a front edge 53 that is an intake inlet toward a rear edge 54 that is an intake outlet. The tip end edge 55 of each blade 52 is formed along the surface shape of a shroud 21 (described later) that faces when the compressor impeller 5 is housed in the impeller chamber 2.

  In the impeller chamber 2, a shroud 21 that covers the side portion of the compressor impeller 5 is formed. The shroud 21 is a shroud surface having a shape along the tip end edge 55 from the front edge portion 53 to the rear edge portion 54 of the compressor impeller 5, more specifically, when the compressor impeller 5 rotates around the rotation axis R. A shroud surface having a shape substantially equal to the envelope surface formed by the tip end edge 55 is provided, and the tip end edge 55 which is a side portion of the compressor impeller 5 is covered by the shroud surface. The front edge 53 side of the shroud 21 is an intake inlet 22 having an inner diameter substantially equal to the outer diameter of the front edge 53. Further, the rear edge portion 54 side of the shroud 21 is an annular intake / discharge port having a width substantially equal to the height of the rear edge portion 54.

  When the turbine impeller of the exhaust turbine connected to the compressor impeller 5 by the rotation shaft R is rotated by the energy of the exhaust gas, for example, the compressor impeller 5 rotates clockwise around the rotation shaft R as viewed from the intake upstream side. When the compressor impeller 5 rotates while being provided in the impeller chamber 2, it flows in along the axis C from the front edge 53 of each blade 52, flows between the blades 52, and has a diameter from each rear edge 54. It discharges toward the direction outside.

  The diffuser chamber 3 is annular and is formed so as to surround the intake / discharge port of the impeller chamber 2. As the compressor impeller 5 rotates, the intake air discharged radially outward from the rear edge 54 is decelerated in the process of flowing in the diffuser chamber 3 while expanding in the radial direction.

  The scroll flow path 4 is annular and is formed so as to surround the impeller chamber 2 and the diffuser chamber 3. The flow passage cross-sectional area of the scroll flow passage 4 gradually increases along the same direction as the rotation direction of the compressor impeller 5. The intake air discharged radially outward from the diffuser chamber 3 is further decelerated in the process of flowing through the scroll flow path 4 and then guided to a combustion chamber of an engine (not shown).

  The intake duct 6 has a substantially cylindrical shape extending along the axis C of the compressor impeller 5. The intake duct 6 extends along the axis C and has a funnel-shaped intake flow path 7 that guides intake air to an intake introduction port 22 formed in the impeller chamber 2, and the inside of the intake flow path 7 and the scroll flow path 4. A drain hole 61 that is a through hole communicating with the drain hole 63, a drain valve 63 that opens and closes an oil flow path that will be described later formed by the drain hole 61, and a water jacket 65 provided in the vicinity of the drain hole 61. Yes.

  The intake passage 7 communicates with the impeller chamber 2 and includes a small diameter portion 71 having an inner diameter corresponding to the intake inlet 22 formed in the impeller chamber 2 and an upstream end opening 72 on the intake upstream side of the small diameter portion 71. A large-diameter portion 75 connected via an annular shoulder 73 and having an inner diameter larger than that of the small-diameter portion 71.

  The inner diameter of the upstream end opening 72 of the small diameter portion 71 is slightly larger than the inner diameter of the intake air inlet 22 having an inner diameter substantially equal to the outer diameter of the front edge portion 53 of the compressor impeller 5. Accordingly, the small diameter portion 71 is formed with a flow path whose diameter is reduced from the upstream side of the intake air toward the impeller chamber 2 on the downstream side.

  The inner wall surface of the shoulder 73 has a bowl-shaped curved surface in which the angle θ formed by the tangent line in the cross section including the axis C and the axis C decreases from the radially inner side to the outer side of the compressor impeller.

  The inner diameter of the large diameter portion 75 is larger than the inner diameter of the upstream end opening 72 of the small diameter portion 71. The large diameter portion 75 and the small diameter portion 71 are substantially coaxial with the axis C as the center. Thereby, an annular curved surface having a width corresponding to the inner diameter difference between the large diameter portion 75 and the small diameter portion 71 is formed on the inner wall surface of the shoulder portion 73 over the entire circumference of the upstream end opening 72.

  In the portion where the large diameter portion 75 and the shoulder portion 73 are connected, the lowest bottom portion 76 of the entire intake flow path 7 is formed in the mounting posture of the compressor housing 1. The bottom 76 is concave in a vertically mounted manner in the mounting posture.

  The drain hole 61 is a through hole that extends downward in the vertical direction in the mounting posture from the bottom of the bottom portion 76 and reaches the introduction portion 41 provided at a position lower than the bottom portion 76 in the mounting posture in the scroll channel 4. The inside of the intake passage 7 and the inside of the scroll passage 4 are communicated by an oil passage 62 formed by the drain hole 61.

  As shown in FIG. 2, the introduction portion 41 of the scroll flow path 4 is slightly inclined vertically downward in the mounting posture of the compressor housing. Therefore, the drain opening 42 formed in the introduction portion 41 by the drain hole 61 is also slightly inclined downward in the mounting posture.

  The drain valve 63 includes a valve body 631 that is larger than the drain opening 42, and a shaft body 632 that is provided on the vertically upper side of the drain opening 42 in the introduction portion 41 and pivotally supports the valve body 631. As a result, communication between the bottom 76 and the inside of the scroll channel 4 via the oil channel 62 is connected or blocked.

  More specifically, when the pressure inside the intake passage 7 upstream of the compressor impeller 5 and the pressure inside the scroll passage 4 downstream of the compressor impeller 5 are substantially equal, that is, the rotation speed of the compressor impeller 5. When the engine is operated at a low load, the valve body 631 is separated from the drain opening 42 by its own weight, so that communication between the bottom 76 and the inside of the scroll flow path 4 is connected. That is, the drain valve 63 is opened when the engine is operated at a low load. Further, when the pressure inside the scroll flow path 4 is higher than the pressure inside the intake flow path 7, that is, at the time of high load operation of the engine where the rotation speed of the compressor impeller 5 becomes high, the valve body 631 opens the drain due to the differential pressure. 42, the communication between the bottom 76 and the inside of the scroll channel 4 is blocked. That is, the drain valve 63 is closed during high-load operation of the engine.

  The water jacket 65 is, for example, an annular cooling water passage formed around the oil passage 62. The water jacket 65 is supplied with, for example, engine cooling water, thereby cooling the oil in the oil passage 62.

  The breather duct 8 is a pipe member, and a breather flow is formed in the inside of the compressor housing 1 so as to communicate the pipe connection portion 81 provided in the vertical direction above the bottom portion 76 and the intake passage 7 in the mounting posture. A path 82 is formed. The breather passage 82 extends, for example, from the pipe connection portion 81 downward in the vertical direction in the mounting posture and reaches a blow-by gas introduction portion 77 provided in the intake passage 7. Further, the above-described breather pipe 96 (see FIG. 1) is connected to the pipe connection portion 81. As will be described below, in order to properly separate the oil contained in the blow-by gas at the shoulder portion 73, the blow-by gas introduction portion 77 is located as close to the compressor impeller 5 as possible in the large-diameter portion 75, that is, as shown in FIG. As shown in FIG. 2, it is preferably provided at a portion where the large diameter portion 75 and the shoulder portion 73 are connected. As a result, the blow-by gas discharged from the breather pipe 96 is guided along the annular inner wall surface of the shoulder 73 into the intake passage 7 via the breather passage 82.

  Next, the effect of the compressor housing 1 configured as described above will be described with reference to FIGS. 3 and 4.

FIG. 3 is a cross-sectional view showing the configuration of the compressor housing 1 during high-load operation of the engine.
First, during high-load operation of the engine, since a differential pressure is generated between the inside of the intake passage 7 and the inside of the scroll passage 4 as described above, the drain valve 63 is closed. Further, when the engine is in a high load operation, the compressor impeller 5 rotates at a high speed in order to increase the supercharging pressure and supply more intake air to the engine. Therefore, a swirling flow in the same direction as the rotation direction of the compressor impeller 5 is generated in the intake flow path 7 upstream of the compressor impeller 5 as indicated by an arrow 3a in FIG. For this reason, the blow-by gas introduced into the large-diameter portion 75 via the breather channel 82 is separated into a relatively light gas component and heavy oil by the swirl flow. Here, the relatively light gas component flows into the impeller chamber 2 through the small diameter portion 71 that is coaxial and small in diameter with the large diameter portion 75, and the relatively heavy oil is the shoulder portion as shown by an arrow 3 b in FIG. 3. A circular curved surface formed on the inner wall surface of 73 is turned. At this time, since the drain valve 63 is closed as described above, a part of the oil swirling on the inner wall surface of the shoulder 73 is accumulated in the bottom 76 and the oil flow path 62 by its own weight. As described above, the oil in the blow-by gas can be stored in the bottom 76 and the oil flow path 62 without entering the impeller chamber 2 when the engine is operated at a high load.

FIG. 4 is a cross-sectional view showing the configuration of the compressor housing 1 during low-load operation of the engine.
During low load operation of the engine that does not require supercharging by the compressor, the compressor impeller 5 rotates or stops at a lower speed than during high load operation. For this reason, the oil swirling the inner wall surface of the shoulder portion 73 by the swirling flow during the high load operation hangs down to the bottom portion 76 due to its own weight. When the compressor impeller 5 rotates or stops at a low speed, the pressure inside the intake passage 7 and the pressure inside the scroll passage 4 become substantially equal to the atmospheric pressure, and the drain valve 63 is opened. For this reason, as described above, the oil accumulated in the oil flow path 62 and the bottom 76 during the high load operation flows into the scroll flow path 4 through the drain opening 42 by its own weight.

According to the compressor housing 1 of the present embodiment, the following effects can be obtained.
(1) The compressor housing 1 is connected to a small diameter portion 71 having an inner diameter corresponding to the outer diameter of the front edge portion 53 of the compressor impeller 5 through an annular shoulder portion 73 at an upstream end opening 72 of the small diameter portion 71. The funnel-shaped intake flow path 7 is formed by the large-diameter portion 75 having a larger inner diameter than the small-diameter portion 71. In the compressor housing 1, the lowest bottom portion 76 of the intake passage 7 is formed in a mounting posture at a portion connecting the large diameter portion 75 and the shoulder portion 73, and a drain hole 61 is formed in the bottom portion 76. Is done. As a result, the blow-by gas is separated into a relatively light gas component and a relatively heavy oil by the swirling flow generated in the intake passage 7 when the compressor impeller 5 rotates at a high speed, so that the oil enters the impeller chamber 2. Can be suppressed. The separated oil can be stored in the bottom 76 when the compressor impeller 5 rotates at a high speed, for example. The oil stored in the bottom 76 can be returned to other parts other than the impeller chamber 2 through the drain hole 61 at an appropriate timing, for example, when the compressor impeller 5 rotates at a low speed. Therefore, according to the compressor housing 1, the oil in the blow-by gas can be prevented from entering the impeller chamber 2 during both the low speed rotation and the high speed rotation of the compressor impeller 5; It is also possible to suppress sticking in the diffuser chamber 3.

  (2) According to the compressor housing 1, the inner wall surface of the shoulder portion 73 has a curved surface in which the angle formed by the tangent line and the axis C in the cross section including the axis C decreases as it goes from the radially inner side to the outer side of the compressor impeller 5. Is provided. As a result, when a swirling flow is generated in the intake flow path 7, relatively heavy oil contained in the blow-by gas is separated from the radially outer side of the inner wall surface of the shoulder portion 73, that is, from the small diameter portion 71 by centrifugal force. Therefore, the oil in the blow-by gas can be further prevented from entering the impeller chamber 2.

  (3) According to the compressor housing 1, the bottom portion 76 is concave in the mounting posture and extends vertically upward, and the drain hole 61 is formed at the bottom of the bottom portion 76. Thereby, even if a large amount of oil is separated, the large amount of oil can be stored in the bottom 76 without flowing out to the inside of the impeller chamber 2. Further, the oil accumulated in the bottom portion 76 can be refluxed to other portions other than the impeller chamber 2 through the drain hole 61.

  (4) According to the compressor housing 1, the diffuser chamber 3 is formed around the impeller chamber 2, the scroll channel 4 is formed around the diffuser chamber 3, and the drain hole 61 is formed between the bottom 76 and the scroll channel 4. A through-hole that communicates with the introduction portion 41 provided in a portion lower than the bottom portion 76 in the mounting posture. Since the impeller chamber 2 is provided with the compressor impeller 5, when oil flows into the impeller chamber 2, the oil adheres to the compressor impeller 5 and the performance of the compressor 92 </ b> C may be degraded. Further, since the diffuser chamber 3 is narrower than the scroll flow path 4, the diffuser chamber 3 is easily fixed when oil flows in, and the performance of the compressor 92C is greatly deteriorated due to the oil fixing. In the compressor housing 1, the bottom portion 76 of the intake passage 7 and the introduction portion 41 of the scroll passage 4 are connected by the drain hole 61, so that the oil accumulated in the bottom portion 76 can be transferred to the impeller chamber 2 having a low oil adhesion toughness and It is possible to prevent the oil from flowing into the diffuser chamber 3 and to introduce the oil into the scroll flow path 4 having a higher oil adhesion. Further, by connecting the bottom portion 76 of the intake passage 7 and the introduction portion 41 that is lower than the bottom portion 76 in the mounting posture in the scroll passage 4, the oil accumulated in the bottom portion 76 is scrolled using its own weight. It can be introduced into the flow path 4.

  (5) The compressor housing 1 further includes a drain valve 63 that connects or blocks communication between the bottom portion 76 and the inside of the scroll flow path 4, and is closed during high load operation and opened during low load operation. . Therefore, during a high load operation in which the inside of the scroll flow path 4 is relatively hot, the oil in the blow-by gas is centrifuged at the shoulder 73 by the swirl flow generated in the intake flow path 7, During a low load operation at a relatively low temperature, the oil centrifuged during the high load operation can be returned to the scroll flow path 4 through the drain hole 61. As a result, the oil in the blow-by gas can be recirculated into the intake air without being exposed to a high temperature.

  (6) The compressor housing 1 further includes a water jacket 65 that flows in the vicinity of the drain hole 61. Thereby, since the oil before reaching the scroll flow path 4 through the drain hole 61 can be cooled by the cooling water, the oil sticking in the scroll flow path 4 can be suppressed.

  (7) According to the compressor housing 1, the drain opening 42 is inclined vertically downward in the mounting posture, and the valve body 631 is rotated by the shaft body 632 provided vertically above the inclined drain opening 42. It is pivotally supported. Thereby, at the time of low load operation, since the inside of the scroll flow path 4 has a relatively low pressure, the valve body 631 can be opened by its own weight. Further, since the inside of the scroll flow path 4 becomes relatively high during a high load operation, the valve body 631 can be closed using the pressure in the scroll flow path 4. That is, according to the compressor housing 1, the valve body 631 can be opened and closed at an appropriate timing according to the operating state of the engine without using an electromagnetic actuator.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 5 is a cross-sectional view of the compressor housing 1A according to the present embodiment. Note that the vertical direction in FIG. 5 is the same as the vertical direction of the compressor housing 1A in the mounting posture as in FIG. Below, about the structure of 1 A of compressor housings, the same thing as the compressor housing 1 which concerns on 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits the description. The compressor housing 1A is different from the compressor housing 1 according to the first embodiment in that the compressor housing 1A further includes an electromagnetic actuator 66 and a controller 67 thereof.

  The electromagnetic actuator 66 includes a shaft 661 that is connected to the valve body 631 at the distal end thereof, and a solenoid 662 that moves the shaft 661 forward and backward by electromagnetic force and elastic force of a spring (not shown). In a state where the energization to the solenoid 662 is stopped, the shaft 661 advances from the solenoid 662 by the elastic force of the spring, whereby the valve body 631 is pressed against the drain opening 42 and the drain valve 63 is closed. When the drive current is supplied to the solenoid 662 and the solenoid 662 is energized, the shaft 661 retracts toward the solenoid 662 against the elastic force of the spring, whereby the valve body 631 is separated from the drain opening 42, and the drain valve 63 opens.

  The controller 67 controls the drive current supplied from the battery (not shown) to the solenoid 662 in accordance with the operating state of the engine. More specifically, the controller 67 supplies a predetermined drive current to the solenoid 662 to close the drain valve 63 when the engine is in a high load operation, and opens the drain valve 63 when the engine is in a low load operation. Therefore, the energization to the solenoid 662 is stopped.

According to the compressor housing 1A of the present embodiment, the following effects are obtained.
(8) The compressor housing 1A further includes an electromagnetic actuator 66 and a controller 67 that use electromagnetic force to close the drain valve 63 during high load operation and open the drain valve 63 during low load operation. Accordingly, even when the valve body 631 is difficult to open and close due to the viscosity of the oil, the drain valve 63 can be opened and closed at an appropriate timing according to the operating state of the engine.

  In the second embodiment, when the drain valve 63 is opened and closed using the electromagnetic actuator 66 and the controller 67, the drain valve 63 is closed when the drive current is supplied to the electromagnetic actuator 66, and the electromagnetic actuator 66 is opened. The drain valve 63 is opened when the energization is stopped, but the present invention is not limited to this. On the contrary, the drain valve 63 may be opened when a drive current is supplied to the electromagnetic actuator 66, and the drain valve 63 may be closed when the energization of the electromagnetic actuator 66 is stopped. Moreover, although the said 2nd Embodiment demonstrated the case where the drain valve 63 was opened and closed using the electromagnetic force which generate | occur | produces with the electromagnetic actuator 66, this invention is not limited to this. For example, the drain valve 63 may be opened and closed by displacing the diaphragm using negative pressure generated in the intake air passage of the engine.

<Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to the drawings.
FIG. 6 is a cross-sectional view of the compressor housing 1B according to the present embodiment. Note that the vertical direction in FIG. 6 is the same as the vertical direction of the compressor housing 1B in the mounting posture as in FIG. Below, about the structure of the compressor housing 1B, the same thing as the compressor housing 1 which concerns on 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits the description. The compressor housing 1B is different from the compressor housing 1 according to the first embodiment in that the configuration of the intake duct 6B, the supply destination of oil accumulated in the bottom 76, and the electromagnetic actuator 66B and its controller 67B are further provided.

  A breather return pipe connecting portion 83 to which the breather return pipe 99 is connected is formed at a position lower than the bottom 76 of the intake flow path 7 in the mounting posture on the outside of the compressor housing 1B. One end of the breather recirculation pipe 99 is connected to the breather recirculation pipe connecting portion 83, and the other end is connected to a crankcase of an engine (not shown). Thereby, the breather recirculation pipe connecting portion 83 and the crankcase communicate with each other.

  The intake duct 6B includes an intake flow path 7, a drain hole 61B, a drain valve 63B, an electromagnetic actuator 66B, and a controller 67B thereof.

  The drain hole 61 </ b> B is a through hole that extends downward from the bottom of the bottom 76 in the vertical direction in the mounting posture and reaches the breather return pipe connecting portion 83. The inside of the intake passage 7 communicates with the inside of the breather recirculation pipe connecting portion 83 and the crankcase through an oil passage 62B formed by this drain hole 61B.

  The drain valve 63B supports the valve body 631B larger than the drain opening 68B formed in the oil flow path 62B and the valve body 631B on the drain opening 68B, and this valve body in accordance with the advancement and retreat of the shaft 661B described later. And a link mechanism 633B for rotating 631B.

  The electromagnetic actuator 66B includes a shaft 661B that is connected to the link mechanism 633B at the tip thereof, and a solenoid 662B that advances and retracts the shaft 661B by electromagnetic force and elastic force of a spring (not shown). In a state where energization to the solenoid 662B is stopped, the shaft 661B moves forward from the solenoid 662B by the elastic force of the spring, whereby the valve body 631B is pressed against the drain opening 68B, and the drain valve 63B is closed. When the drive current is supplied to the solenoid 662B and the solenoid 662B is energized, the shaft 661B retreats toward the solenoid 662B against the elastic force of the spring, whereby the valve body 631B is separated from the drain opening 68B, and the drain valve 63B opens.

  The controller 67B controls a drive current supplied from a battery (not shown) to the solenoid 662B according to the operating state of the engine. More specifically, the controller 67B supplies a drive current of a predetermined magnitude to the solenoid 662B so as to close the drain valve 63B when the engine is in a high load operation, and opens the drain valve 63B when the engine is in a low load operation. Therefore, the energization to the solenoid 662B is stopped.

According to the compressor housing 1B of the present embodiment, the following effects can be obtained.
(9) According to the compressor housing 1B, a breather recirculation pipe connecting portion 83 to which a breather recirculation pipe 99 communicating with the crankcase is connected is formed on the outer side, and the drain hole 61B is formed between the bottom 76 of the intake passage 7 and the breather. A through-hole communicating with the reflux pipe connecting portion 83 is used. As a result, the oil accumulated in the bottom 76 can be recirculated into the crankcase via the breather recirculation pipe 99.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described with reference to the drawings.
FIG. 7 is a cross-sectional view of the compressor housing 1C according to the present embodiment. Note that the vertical direction in FIG. 7 is the same as the vertical direction of the compressor housing 1C in the mounting posture as in FIG. Below, about the structure of 1 C of compressor housings, the same thing as the compressor housing 1 which concerns on 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits the description. The compressor housing 1C is different from the compressor housing 1 according to the first embodiment in the configuration of the breather duct 8C, the configuration of the intake duct 6C, and the supply destination of the oil accumulated in the bottom portion 76.

  The breather duct 8 </ b> C is a pipe member, and a breather flow that communicates between the pipe connection portion 81 </ b> C provided in the vertical direction below the bottom portion 76 in the mounting posture of the outside of the compressor housing 1 and the intake passage 7. A path 82C is formed. The breather flow path 82C extends from the pipe connection portion 81C upward in the vertical direction in the mounting posture and reaches the bottom portion 76. The above-described breather pipe 96 (see FIG. 1) is connected to the pipe connection portion 81C. Thereby, the blow-by gas discharged from the breather pipe 96 is guided along the inner wall surface of the shoulder 73 into the intake passage 7 via the breather passage 82C.

  The drain hole 61C is a through hole that extends from the bottom of the bottom 76 downward in the vertical direction in the mounting posture and reaches the pipe connection portion 81C of the breather duct 8C. That is, the oil flow path formed by the drain hole 61C is the same as the breather flow path 82C. Therefore, the inside of the intake passage 7 and the inside of the crank connection of the engine connected by the pipe connecting portion 81C and the pipe connecting portion 81C by the breather pipe 96 are communicated by the breather passage 82C formed by the drain hole 61C. To do.

According to the compressor housing 1C of the present embodiment, the following effects can be obtained.
(10) According to the compressor housing 1 </ b> C, the oil in the blow-by gas supplied from the bottom portion 76 of the intake passage 7 is separated by the swirl flow generated in the intake passage 7, and then again from the bottom portion 76 to the breather pipe. It is recirculated into the crankcase through 96. Therefore, according to the compressor housing 1 </ b> C, the oil in the blow-by gas can be recirculated into the crankcase without entering the impeller chamber 2 with a simple configuration.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to this. Within the scope of the gist of the present invention, the detailed configuration may be changed as appropriate.

  In the above-described embodiment, the example in which the rotation direction of the compressor impeller 5 is clockwise when viewed from the upstream side has been described. However, the rotation direction of the compressor impeller 5 may be reversed. Moreover, although the said embodiment demonstrated the case where the axis line of a compressor impeller became horizontal in the mounting attitude | position of a compressor housing, the mounting attitude | position of a compressor housing is not restricted to this. That is, a posture in which the axis is inclined with respect to a horizontal plane so that the upstream side is at a high place may be set as the compressor housing mounting posture. However, even when the axis is inclined as described above, it is preferable that the lowest bottom portion of the entire intake flow path is formed at a portion connecting the large diameter portion and the shoulder portion.

DESCRIPTION OF SYMBOLS 1,1A, 1B, 1C ... Compressor housing 2 ... Impeller chamber 3 ... Diffuser chamber 4 ... Scroll flow path 41 ... Introduction part 42 ... Drain opening (opening)
5 ... Compressor impeller (impeller)
53 ... Leading edge portion 61, 61B, 61C ... Drain hole 631 ... Valve body 632 ... Shaft body 65 ... Water jacket (cooling water flow path)
66 ... Electromagnetic actuator (opening / closing means)
67 ... Controller (opening / closing means)
8 ... Breather duct 81, 81C ... Pipe connection (breather pipe connection)
82, 82C ... Breather flow path 83 ... Breather recirculation piping connection part 7 ... Intake flow path 71 ... Small diameter part 72 ... Upstream end opening (upstream end)
73 ... Shoulder 75 ... Large diameter portion 76 ... Bottom 92C ... Compressor 96 ... Breaser piping 99 ... Breaser reflux piping (Breaser reflux piping)
C ... Axis R ... Rotary axis

Claims (10)

A compressor housing for a compressor that pressurizes intake air of an internal combustion engine using an impeller,
The compressor housing includes an impeller chamber that rotatably accommodates the impeller, an intake passage that extends along an axis of the impeller and guides intake air to a front edge portion of the impeller, and a breather through which blow-by gas of the internal combustion engine flows. A breather flow path connected to the pipe for guiding the blow-by gas into the intake flow path,
The intake passage is connected to the small diameter portion communicating with the impeller chamber and having an inner diameter corresponding to the outer diameter of the front edge portion of the impeller, and an annular shoulder portion at an upstream end of the small diameter portion. A large diameter portion having an inner diameter larger than the portion,
In the portion connecting the large diameter portion and the shoulder portion, the lowest bottom portion of the intake passage is formed in the mounting posture of the compressor housing,
A compressor housing characterized in that a drain hole is formed in the bottom.   The inner wall surface of the shoulder portion includes a curved surface in which an angle formed between a tangent line and the axis line in a cross section including the axis line decreases from the inner side toward the outer side in the radial direction of the impeller. The compressor housing as described. The bottom is concave upward in the mounting posture,
The compressor housing according to claim 1, wherein the drain hole is formed in a bottom of the bottom portion. The compressor housing is provided around the impeller chamber, and is provided around the diffuser chamber, the diffuser chamber that decelerates the intake air discharged from the impeller chamber in the radial direction of the impeller, and from the diffuser chamber to the impeller An annular scroll flow path through which intake air discharged in the radial direction of
The said drain hole is a through-hole which connects the said bottom part and the introducing | transducing part provided in the part lower than the said bottom part by the said mounting attitude | position among the said scroll flow paths. A compressor housing according to any one of the above. The compressor housing further includes a valve body for connecting or blocking communication between the bottom portion and the inside of the scroll flow path via the through hole,
5. The compressor housing according to claim 4, wherein the valve body is closed when the internal combustion engine is operated at a high load and is opened when the internal combustion engine is operated at a low load.   The compressor housing according to claim 4, wherein the compressor housing further includes a cooling water passage that flows in the vicinity of the through hole. The opening on the introduction part side of the through hole is inclined vertically downward in the mounting posture,
The compressor housing according to claim 5, wherein a shaft body that pivotally supports the valve body on a vertically upper side of the opening is provided in the introduction portion.   The said compressor housing is further provided with the opening-and-closing means which closes the said valve body at the time of the high load driving | operation of the said internal combustion engine, and opens the said valve body at the time of the low load driving | running of the said internal combustion engine. Compressor housing. On the outside of the compressor housing, a breather recirculation pipe connecting portion to which a breather recirculation pipe communicating with the crankcase of the internal combustion engine is connected is formed.
The compressor housing according to any one of claims 1 to 3, wherein the drain hole is a through hole that communicates the bottom portion and the breather recirculation pipe connecting portion. A breather pipe connecting portion to which the breather pipe is connected is formed outside the compressor housing,
The drain hole is a through hole that communicates the bottom part and the breather pipe connection part,
The compressor housing according to any one of claims 1 to 3, wherein the breather passage is a passage formed by the through hole.

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