The disclosure relates to an oil mist separator for separating an oil mist from a blow-by gas in an internal combustion engine.
In an internal combustion engine for an automobile, it is known that a blow-by gas containing an unburned component leaking from a combustion chamber of an internal combustion engine into a crankcase is introduced into an intake system of an internal combustion engine to be combusted. Further, since the blow-by gas passing through the crankcase contains oil mist, in order to prevent the oil mist from flowing into the intake system of the internal combustion engine, it is possible to provide an oil mist separator for separation/removal of oil mist in blow-by gas inside a cylinder cover. For example, Patent Document 1 discloses a separating component composed of a perforated plate, a fiber material such as fleece, and an impact plate, thereby separating/removing the oil mist by colliding the blow-by gas with the impact plate after passing through the perforated plate and the fiber material.
[Patent Document 1] Japanese Laid-open No. 2016-114035
In the related art, even if the oil mist can be separated from the blow-by gas through the separating component, the oil mist on the downstream side of the separating component may be drawn in the blow-by gas again, and supplied to the intake system of the internal combustion engine with the blow-by gas.
The disclosure provides an oil mist separator for preventing the oil mist located downstream relative to the separating component from being drawn in the separated blow-by gas and supplied to intake system of the internal combustion engine.
An oil mist separator of an exemplary embodiment of the disclosure is configured for separating an oil mist from a blow-by gas in an internal combustion engine, wherein the oil mist separator includes a separator case, a gas inlet portion, a gas outlet portion, a separating component, and a wall portion. The separator case is formed with a gas flow path through which the blow-by gas flows. The gas inlet portion introduces the blow-by gas into the separator case on one side of the gas flow path. The gas outlet portion discharges the blow-by gas out of the separator case on the other side of the gas flow path. The separating component is disposed in the separator case and located between the gas inlet portion and the gas outlet portion to separate the oil mist from the blow-by gas when the blow-by gas flows along the gas flow path. The wall portion is erected on a bottom wall in the separator case, and faces the gas outlet portion at a position leaning toward the gas outlet portion between the separating component and the gas outlet portion.
Reference will now be made in detail to the present embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Further, the gas inlet portion 120 is an opening structure provided in one of the side walls 114 of the separator case 110, and introduces the blow-by gas into the separator case 110 on one side of the gas flow path (for example, the flow direction indicated by the arrow D shown in
In the exemplary embodiment, the oil mist separator 100 further includes a check valve 160. The check valve 160 is disposed at the gas outlet portion 130 for opening or closing the gas outlet portion 130 to control whether the blow-by gas in the separator case 110 flows out of the gas outlet portion 130 or not. That is, when the check valve 160 is opened, the blow-by gas from which the oil mist is separated may flow from the gas outlet portion 130, and when the check valve 160 is closed, the blow-by gas from which the oil mist is separated does not flow from the gas outlet portion 130. Please refer to the following description regarding when the check valve 160 controls whether or not the blow-by gas flows from the gas outlet portion 130. However, in other embodiments that are not shown, the oil mist separator 100 may also be provided with other kinds of valves at the gas outlet portion 130. The disclosure provides no limitation to the type and setting of the valve, which may be adjusted according to needs.
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Further, in the exemplary embodiment, the bottom wall 116 is provided with an oil discharge portion 170 located downstream relative to the separating component 140 on a gas flow path (for example, a flow direction indicated by an arrow D shown in
In addition, in the exemplary embodiment, the wall portion 150 is erected on the bottom wall 116 in the separator case 110 in a manner that a gap d is provided between the wall portion 116 and the side wall (at an edge 116a corresponding to the bottom wall 116 after assembling) of the separator case 110, thereby preventing the separated oil mist from being accumulated in a region located downstream relative to the wall portion 150 on the bottom wall 116, but the disclosure is not limited thereto. Further, in the bottom wall 116, a portion R1 located downstream relative to the separating component 140 and located upstream relative to the oil discharge portion 170 on the gas flow path (for example, the flow direction indicated by the arrow D shown in
In the case where the oil mist separator 100 is mounted to the internal combustion engine 50, the oil mist separator 100 may be mounted to the PCV chamber 51, and the passage 57 directly connects the gas outlet portion 130/check valve 160 of the oil mist separator 100 mounted to the PCV chamber 51 and the intake manifold 53 without passing through the passage 59. The downstream end of the oil mist separator 100 (i.e., corresponding to the gas outlet portion 130/check valve 160) communicates with the intake system located downstream relative to the throttle valve 54 used in the internal combustion engine 50, thereby separating the oil mist from the blow-by gas flowing into the PCV chamber 51 through the oil mist separator 100, and the check valve 160 is used as a PCV valve to open or close the PCV chamber 51.
In this manner, when the intake manifold 53 is in the negative pressure state, the check valve 160 is opened so that the blow-by gas is sucked into the intake manifold 53 via the PCV chamber 51, the check valve 160 and the passage 57. In this process, the oil mist contained in the blow-by gas is separated/removed through the oil mist separator 100 (corresponding to the position of the check valve 160) in the PCV chamber 51, and then the blow-by gas not containing the oil mist is supplied from the check valve 160 to the intake manifold 53 via the passage 57. In the meantime, fresh air is supplied to the crankcase via the passage 58 and the internal space of the breather chamber 52 to ventilate the crankcase. In contrast, when the intake manifold 53 is in the positive pressure state, the check valve 160 is closed so that blow-by gas is sucked into the passage 59 that serves as the intake system located upstream relative to the throttle valve 54 at this time via the breather chamber 52 and the passage 58. During this process, the oil mist contained in the blow-by gas is separated/removed in the breather chamber 52 (for example, an oil mist separator 100 or other separating component (not shown) may also be installed in the breather chamber 52), and then the blow-by gas that does not contain the oil mist is supplied from the throttle valve 54 to the intake manifold 53. That is, the check valve 160 is opened when the intake manifold 53 is in a negative pressure state to allow the blow-by gas to flow from PCV chamber 51 to the passage 57, and the check valve 160 is closed when the intake manifold 53 is in the positive pressure state to control the flow of the blow-by gas from which the oil mist has been separated in the PCV chamber 51. However, the above-mentioned application of the oil mist separator 100 in the internal combustion engine (particularly the PCV chamber 51) is only one of the examples, and the disclosure provides no limitation to the application of the oil mist separator 100, which may be adjusted according to needs.
In summary, in the oil mist separator of the embodiment of the disclosure, a separating component for separating the oil mist from the blow-by gas is installed in the separator case, and the wall portion is erected on the bottom wall in the separator case and faces the gas outlet portion at a position leaning toward the gas outlet portion between the separating component and the gas outlet portion on the gas flow path. That is, during the process of flowing to the gas outlet portion, the blow-by gas separated by the separating component collides with the wall portion again to separate the oil mist, thereby reducing the possibility that the oil mist located downstream relative to the separating component is drawn into the separated blow-by gas again. Additionally, since the height of the wall portion is equal to or higher than the height of the lowermost side of the gas outlet portion, and the wall portion is erected on the bottom wall in the manner that a gap is provided between the wall portion and the sidewall of the separator case, so that the wall portion can guide the blow-by gas to flow smoothly toward the gas outlet portion, and prevent the separated oil mist from being accumulated on the region of the bottom wall downstream relative to the wall portion. Accordingly, the oil mist separator in the disclosure can prevent the oil mist located downstream relative to the separating component from being drawn into the separated blow-by gas and supplied to the intake system of the internal combustion engine along with the blow-by gas.
In an oil mist separator according to an exemplary embodiment of the disclosure, the gas outlet portion is disposed on a side wall of the separator case, and a height of the wall portion relative to the bottom wall is equal to or higher than a height of the lowermost side of the gas outlet portion relative to the bottom wall.
An oil mist separator according to an exemplary embodiment of the disclosure further includes a check valve disposed at the gas outlet portion, a height of the wall portion relative to the bottom wall is equal to or higher than a height of the lowennost side of the check valve relative to the bottom wall.
In an oil mist separator according to an exemplary embodiment of the disclosure, the wall portion is erected on the bottom wall in the separator case in a manner that a gap is provided between the wall portion and a side wall of the separator case.
In an oil mist separator according to an exemplary embodiment of the disclosure, the bottom wall has an oil discharge portion located downstream relative to the separating component on the gas flow path to discharge the oil droplets aggregated by the oil mist separated by the separating component out of the separator case.
In an oil mist separator according to an exemplary embodiment of the disclosure, the wall portion is located downstream relative to the oil discharge portion on the gas flow path.
In an oil mist separator according to an exemplary embodiment of the disclosure, the wall portion is located between the oil discharge portion and the gas outlet portion.
In an oil mist separator according to an exemplary embodiment of the disclosure, in the bottom wall, a portion located downstream relative to the separating component and located upstream relative to the oil discharge portion on the gas flow path is inclined downward from the separating component toward the oil discharge portion, and a portion located downstream relative to the oil discharge portion and located upstream relative to the gas outlet portion on the gas flow path is inclined downward from the gas outlet portion toward the oil discharge portion.
In an oil mist separator according to an exemplary embodiment of the disclosure, the wall portion is a plate structure facing the gas outlet portion.
In an oil mist separator according to an exemplary embodiment of the disclosure, in the case where the oil mist separator is installed in the internal combustion engine, a downstream end of the oil mist separator communicates with an intake system located downstream relative to a throttle valve used in the internal combustion engine.
Based on the above, in the oil mist separator of the embodiment of the disclosure, a separating component for separating the oil mist from the blow-by gas is installed in the separator case, and the wall portion is erected on the bottom wall in the separator case and faces the gas outlet portion at a position leaning toward the gas outlet portion between the separating component and the gas outlet portion on the gas flow path. That is, during the process of flowing to the gas outlet portion, the blow-by gas separated by the separating component collides with the wall portion again to separate the oil mist, thereby reducing the possibility that the oil mist located downstream relative to the separating component is drawn in the separated blow-by gas again. Accordingly, the oil mist separator in the embodiment of the disclosure can prevent the oil mist located downstream relative to the separating component from being drawn in the separated blow-by gas and supplied to the intake system of the internal combustion engine.