JP2015217367A5 - - Google Patents

Description

Oil separator

  The present invention relates to an oil separator, and more particularly to a technique for suppressing a phenomenon in which oil separated by an oil separator flows upward together with blow-by gas.

  As an oil separator configured as described above, in Patent Document 1, a valve seat is disposed below an inlet below a separation chamber that constitutes an oil separator, and a first valve body on the inlet side and a valve seat side are arranged. The valve mechanism which connected the 2nd valve body of this with the valve rod is shown. In Patent Document 1, when a pressure difference is generated between the crank chamber pressure and the intake manifold pressure, the valve mechanism is operated up to a position where it abuts on the inlet side or the valve seat by the vertical operation of the valve mechanism. Oil will stay in either of the valve seats.

  Further, when the crank chamber pressure and the intake manifold pressure are substantially equal, the valve mechanism is held at a position where the inlet and the valve seat are opened, and when there is oil remaining inside, the crank chamber Allows downflow to

  Patent Document 2 discloses a configuration in which a baffle plate is provided in a portion from the oil discharge port toward the exhaust pipe inside the case member constituting the oil separator. In this configuration, when an air flow is generated upward, the baffle plate blocks the gas flowing upward from the oil discharge port, and the baffle plate causes the gas to flow on the inner peripheral surface of the oil separator, so that the upper swirl flow And is configured to centrifuge oil.

Japanese Patent Laid-Open No. 2003-13723 JP 2007-263066 A

  The blow-by gas generated in the crankcase of the internal combustion engine contains unburned gas and oil mist of engine oil, so it is not released into the atmosphere as it is but supplied to the combustion chamber of the internal combustion engine and burned with the mixture. .

  Further, when blow-by gas containing oil mist is burned together with the air-fuel mixture in the combustion chamber of the internal combustion engine, the emission is deteriorated and the reduction of engine oil is promoted. Therefore, oil contained in blow-by gas is collected by an oil separator and returned to the internal combustion engine.

  Since the oil separator is disposed in a path for returning blow-by gas to the intake system of the internal combustion engine, negative pressure acts from the intake system on the internal blow-by gas circulation portion at the intake timing of the internal combustion engine. In addition, in an oil separator configured to collect oil from oil mist contained in blow-by gas sent to the blow-by gas distribution section and discharge the oil by its own weight from an oil discharge port formed at the bottom, the oil separator operates under negative pressure. In some cases, the oil inside the oil separator flows backward from the discharge port, and the oil mists again.

  In order to suppress the phenomenon in which the collected oil flows backward, the configurations of Patent Literature 1 and Patent Literature 2 function effectively. However, in the configuration of Patent Literature 1, a member for operating the valve mechanism is provided. Therefore, in the event of a malfunction, there is room for improvement in terms of stability because the upward flow of gas from the crankcase side cannot be suppressed. Further, in the configuration of Patent Document 2, since the baffle plate is arranged inside the space of the cyclone type oil separator, it is possible to prevent the upward gas flow, but when a strong air flow is generated There is room for improvement because of the backflow of oil.

  The objective of this invention exists in the point which comprises rationally the oil separator which can suppress the phenomenon in which the oil isolate | separated in the oil separation part mixes in blow-by gas.

A feature of the present invention is that a cyclone-type oil separation part that separates oil mist contained in blow-by gas, and a downward flow of oil in a portion that extends downward from the discharge opening that has the smallest diameter at the bottom of the oil separation part. And a reverse flow suppression unit that suppresses the flow of air in the direction opposite to the oil discharge direction while allowing the reverse flow suppression unit from the upper end facing the discharge opening to the lower end of the reverse flow suppression unit Is formed by a non-linear communication path formed in a fixed state with respect to the component of the backflow suppressing portion, the communication path is configured in a spiral shape, and the spiral of the communication path is formed . The direction is set such that the gas flows upward when the gas flows in the same direction as the swirling direction of the blow-by gas in the oil separator .

According to this configuration, the negative pressure acting on the oil separation unit increases, and even in a situation where gas flows from the backflow suppression unit to the oil separation unit, the backflow suppression unit suppresses the flow of gas to the discharge opening side. The flow rate and flow rate of the gas sucked into the oil separation part from the discharge opening do not increase. Since this backflow suppression part is formed by a non-linear flow path formed in a fixed state in the region from the upper end to the lower end of the constituent member, for example, an oil separator provided with a valve body whose conventional position is displaced The configuration is simple compared to the above.
Therefore, the oil separator which can suppress the phenomenon in which the oil separated in the oil separation part is mixed into the blow-by gas is configured.

By forming the backflow suppression portion in the spiral communication path that sends oil from the discharge opening downward, the flow length of the communication path is increased without increasing the vertical dimension of the backflow suppression portion. The resistance acting on the gas flowing through the communication path is increased. As a result, the negative pressure acting on the oil separation part suddenly rises, and even in a situation where the gas rises upward from the discharge opening, the increase in the flow rate and flow rate of the gas flowing in the communication path is limited, Limits the amount and rate of gas rise and suppresses remisting of oil.
In addition, the cyclone type oil separation unit swirls the blow-by gas to separate the oil mist by centrifugal force. If the communication passage is configured to send the gas downward when the gas flows in the same direction as the swirling direction of the blow-by gas in the oil separator, the blow-by gas flows into the communication passage, and the communication passage It was also imagined that it re-misted in contact with the oil flowing down. On the other hand, by setting the spiral direction of the communication path as in the present invention, the phenomenon that the swirling flow of the gas from the oil separation part flows into the communication path is suppressed, and the oil discharge performance is improved. It becomes possible.

  In the present invention, the backflow suppression unit may include a nonwoven fabric that allows permeation of oil flowing down from the discharge opening and suppresses a gas flow in a direction opposite to the permeation of oil.

According to this, the oil mist separated from the blow-by gas at the oil separation part flows downward in the flow path, and permeates the nonwoven fabric when flowing in this way. On the other hand, in the situation where the negative pressure acting on the oil separation part suddenly rises and the gas rises upward from the discharge opening, the nonwoven fabric acts against the gas. Limits the increase in the flow rate and flow rate of the flowing gas and suppresses re-misting of oil.
In the present invention, the backflow suppressing part may be formed integrally with the oil separating part.
In the present invention, the backflow suppressing part may be formed separately from the oil separating part.

  In the present invention, a buffer space having a channel cross-sectional area larger than a channel cross-sectional area of the discharge opening may be provided between the oil separation unit and the backflow suppressing unit.

  According to this, when the negative pressure acting on the intake system connected to the oil separation unit increases, the gas in the buffer space flows from the discharge opening toward the oil separation unit, and is below the buffer space. Reduce the negative pressure acting on the oil separator from the connected flow path. Thereby, the backflow of gas can be suppressed and the remisting of oil can be suppressed more satisfactorily.

It is a vertical side view of an oil separator. It is the II-II sectional view taken on the line of FIG. It is the III-III sectional view taken on the line of FIG. It is sectional drawing which shows an oil separation part and a backflow suppression part. It is sectional drawing which shows the oil separation part and backflow suppression part of another embodiment (a). It is sectional drawing which shows the oil separation part and backflow suppression part of another embodiment (b). It is sectional drawing which shows the oil separation part and backflow suppression part of another embodiment (c).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Basic configuration]
As shown in FIGS. 1 to 4, a gas supply case A, a plurality of cyclone-type oil separation parts B, a backflow suppression part C connected to the lower part of the oil separation part B, a gas discharge case D, and an oil An oil separator is configured with a discharge case E.

  The oil separator is interposed in a path for returning blow-by gas generated in an engine crank chamber as an internal combustion engine to the intake system of the engine, and functions to remove oil mist contained in the blow-by gas.

  In the gas supply case A, a gas suction port 1 to which blow-by gas is supplied is formed, and an oil separation part B is integrally formed in the gas supply case A. The oil separator B has a function of separating and collecting the oil mist contained in the blow-by gas, turning it into droplets, and sending it downward. This oil separator is provided with a plurality of oil separation portions B, and the cylindrical case portion 5 at the top of each oil separation portion B is arranged in parallel so as to be exposed in the internal space of the gas supply case A.

  The backflow suppression unit C is connected to the lower end of the oil separation unit B, discharges the oil droplets in the oil separation unit B into the internal space of the oil discharge case E, and the negative pressure acting on the gas supply case A is suddenly increased. Even in the case where the gas rises, the flow rate of the gas flowing upward in the inside is reduced, thereby suppressing the phenomenon that the gas is jetted into the oil separation part B and preventing the oil from being re-misted.

  A gas discharge port 2 for discharging blow-by gas is formed in the gas discharge case D, and this gas discharge port 2 communicates with the intake path of the engine. The oil discharge case E receives the oil discharged from the backflow suppressing portion C, and has an oil discharge port 3 that is discharged to the outside. The oil discharged from the oil discharge port 3 is stored inside the cylinder head of the engine or the crank Returned to a position such as inside the case.

  In this oil separator, a gas supply case A, a plurality of oil separation portions B, a backflow suppression portion C, a gas discharge case D, and an oil discharge case E are formed of resin. Further, the gas discharge case D is arranged at a position covering the upper part of the gas supply case A, and the oil discharge case E is arranged below the backflow suppressing part C.

[Configuration of oil separator and backflow suppressor]
As shown in FIGS. 1 and 4, the oil separation portion B is integrally formed with a cone portion 6 having a smaller diameter toward the lower side around the pivot axis at the lower position of the cylindrical case portion 5. A discharge opening 7 is formed at a position having the smallest diameter at the lower end inside.

  The cylindrical case portion 5 is provided with a supply port 5A for taking in blow-by gas supplied to the gas supply case A in the tangential direction of the cylindrical case portion 5, and the cylindrical case portion 5 is formed on the bottom wall 10 of the gas discharge case D. The discharge cylinder 11 arranged with the axial core and the coaxial core is integrally formed so as to protrude downward.

  The backflow suppressing part C is spirally guided inside the discharge member 15 (an example of a constituent member) connected to the lower end of the cone part 6 of the oil separation part B to guide the oil from the discharge opening 7 of the cone part 6 downward ( A discharge flow path 16 (an example of a communication path) serving as a spiral hole is provided in a fixed state. That is, in the discharge member 15 as a constituent member of the backflow suppressing portion C, the discharge flow channel 16 is spirally formed as a non-linear communication path in a region reaching from the upper end facing the discharge opening 7 to the lower end of the discharge member 15. Is formed.

  In order to form the discharge flow path 16 of the backflow suppressing portion C, a spiral core mold is set inside a mold for manufacturing the discharge member 15, and after molding with resin, the core mold is rotated. It will be extracted. Further, the discharge channel 16 is not limited to the one formed in the shape of a spiral hole, and a spiral groove serving as a deep groove may be formed inside the discharge member 15. In the case of forming such a spiral groove, a screw-shaped core mold (in the shape of a screw conveyor or the like) is set in the mold for manufacturing the discharge member 15, and the core mold is formed after molding with resin. It will be extracted while rotating.

  The discharge flow path 16 is set to a posture in which the gas flows upward when the gas flows in the same direction as the blow-by gas swirling direction in the oil separator B. That is, the direction of the spiral is set so that even when the blow-by gas is swirled inside the cone portion 6 and reaches the portion of the discharge opening 7, it cannot flow into the discharge passage 16.

  Only one discharge channel 16 may be formed in the backflow suppression unit C, but a plurality of the discharge channels 16 may be formed at the lower end of the oil separation unit B. FIG. 4 shows a structure in which the discharge member 15 of the backflow suppressing portion C is integrally formed at the lower end of the cone portion 6 of the oil separating portion B. It may be configured to be fixed by such means.

[Oil mist collection form]
Since the oil separator is configured in this way, the negative pressure of the intake system acts on the gas discharge port 2 of the gas discharge case D, and this negative pressure is passed through the discharge cylinder 11 to the internal space of the gas supply case A. Act on. The blow-by gas is sucked into the internal space from the gas suction port 1 of the gas supply case A by the action of the negative pressure, and further supplied to any of the supply ports 5A of the plurality of cylindrical case parts 5.

  As described above, the supply port 5A is formed so as to take in the blowby gas in the tangential direction of the cylindrical case portion 5, so that the supplied blowby gas flows along the inner peripheral surface of the cylindrical case portion 5 and swirls. In the state, it moves downward along the inner periphery of the cone portion 6.

  The oil mist contained in the blow-by gas by this turning is collected on the inner peripheral surface of the cone portion 6 by centrifugal force and formed into droplets. The blow-by gas from which the oil mist has been separated and collected flows up into the gas discharge case D ascending the inside of the discharge cylinder 11, and is further sucked into the intake system of the engine from the gas discharge port 2. This blow-by gas is supplied to the combustion chamber of the engine and combusts with the air-fuel mixture.

  Further, the oil dropletized on the inner surface of the cone portion 6 flows downward due to its own weight, flows from the discharge opening 7 to the discharge flow path 16, is discharged from the lower end of the discharge flow path 16 to the oil discharge case E, and finally It will be returned to the engine.

  In particular, in the oil separator of the present invention, since the discharge flow path 16 is formed in a spiral shape (spiral shape), the flow path of the discharge flow path 16 is not increased without increasing the vertical dimension of the backflow suppressing portion C. The channel length of the discharge channel 16 is increased by increasing the length. As a result, even in a situation where the negative pressure acting on the oil separation part B rises rapidly, the flow rate and flow rate of the gas rising from the discharge opening 7 are reduced, and the oil present in the discharge flow path 16 and the cone part 6 Eliminates the phenomenon that the oil on the inner surface is blown up by gas, and suppresses re-misting of oil.

  Further, in the backflow suppression unit C, the setting of the spiral direction of the discharge flow channel 16 suppresses the inconvenience that the swirling flow of gas inside the cone portion 6 enters the discharge flow channel 16, and the oil separation unit B Even when the negative pressure inside the cylindrical case portion 5 rises and the gas rises from the discharge flow path 16 to the discharge opening 7, this gas swirls, so that the gas is blown up linearly upward. Eliminates oil and re-mists the oil better.

[Another embodiment]
The present invention may be configured as follows in addition to the embodiment described above.

(A) As shown in FIG. 5, the backflow suppression unit C includes a flow-down case 21 that guides oil from the discharge opening 7 of the cone portion 6 downward, and a nonwoven fabric 22 provided inside the flow-down case 21. Configure. The nonwoven fabric 22 functions to allow the oil to permeate downward and to provide a large resistance to gas permeation. In this alternative embodiment (a), the flow-down case 21 is configured to be vertically divided into an upper case 21a and a lower case 21b, and the nonwoven fabric 22 is provided so as to be sandwiched between them, so that the nonwoven fabric 22 can be replaced. It is configured.

  In the configuration of this another embodiment (a), the oil mist separated from the blow-by gas at the oil separation part B flows into the flow-down case 21, passes through the nonwoven fabric 22, and is discharged to the outside through the opening at the lower end of the flow-down case 21. . That is, the non-woven fabric 22 is a non-linear communication path formed between a number of fibers forming the non-woven fabric 22, and the negative pressure acting on the oil separation part B rises rapidly, and the discharge opening 7 In the situation where the gas rises from the top to the bottom, resistance is exerted on the gas flowing through the communication path between the fibers of the nonwoven fabric 22, so that the flow rate and flow rate of the gas rising from the discharge opening 7 are reduced to reduce the oil flow. Suppress remisting.

(B) As shown in FIG. 6, by providing a buffer case 25 between the oil separation portion B and the backflow suppression portion C, the flow passage cross-sectional area of the discharge opening 7 is larger than the flow passage cross-sectional area. 7 is formed. In this other embodiment (b), the backflow suppression part C having a configuration in which a discharge flow path 16 that is spiral with respect to the discharge member 15 is formed as in the embodiment is shown, but instead, this is another embodiment. You may apply to what comprised the backflow suppression part C with the flow-down case 21 and the nonwoven fabric 22 like (a).

  With this configuration, even in a situation where the negative pressure acting on the intake system connected to the oil separation part B increases rapidly and the gas rises upward from the discharge opening 7, the buffer space 25S suppresses the gas pressure fluctuation. Then, the action of the negative pressure acting on the backflow suppressing part C connected to the lower side is reduced. Thereby, the backflow of gas is suppressed and the re-misting of oil is suppressed more favorably.

(C) As shown in FIG. 7, as the backflow suppressing portion C of the present invention, the discharge flow path 16 is formed with a single through hole that is spiral with respect to the discharge member 15 connected to the lower end of the cone portion 6. . With this configuration, the flow path resistance of the discharge flow path 16 can be further increased by increasing the flow path length of the discharge flow path 16 as compared with the case where the discharge flow path 16 is formed by a pair of spiral through holes. Thus, even in a situation where the negative pressure acting on the oil separation part B is suddenly increased, the flow rate and flow rate of the gas rising from the discharge opening 7 are further reduced to suppress the re-misting of the oil.

  Moreover, you may combine the discharge flow path 16 of the structure of this another embodiment (c) with the nonwoven fabric 22 of another embodiment (a), or may combine with the buffer space 25S of another embodiment (b). By combining in this way, the backflow of gas is suppressed and the re-misting of oil is further suppressed.

(D) When the discharge flow path 16 is used as the backflow suppressing portion C of the present invention, the discharge flow path 16 is not necessarily formed in a spiral shape, and may be formed in a zigzag shape, for example. In the present invention, the backflow suppression unit C may be configured by combining the discharge flow path 16 and the nonwoven fabric 22.

  The present invention can be used for an oil separator provided with a cyclone type oil separator.

7 discharge opening 15 component (discharge member)
16 Communication path (discharge flow path)
22 Nonwoven fabric 25S Buffer space B Oil separation part C Backflow suppression part

Claims (5)

The cyclone-type oil separation part that separates the oil mist contained in the blow-by gas, and the flow of the oil downward while allowing the oil to flow downward at the part that extends downward from the discharge opening that is the smallest diameter at the bottom of the oil separation part. Constructed with a backflow suppression unit that suppresses the flow of air in the direction opposite to the discharge direction,
In the region where the backflow suppressing portion reaches the lower end of the backflow suppressing portion from the upper end facing the discharge opening, the backflow suppressing portion is formed by a non-linear communication path formed in a fixed state with respect to the constituent members of the backflow suppressing portion. ,
The communication path is configured in a spiral shape, and when the gas flows in the same direction as the blow-by gas swirling direction in the oil separation portion, the communication path is configured to flow the gas upward. Set oil separator. The backflow inhibiting unit, wherein while allowing the permeation of the oil flowing down from the discharge opening, the oil separator of claim 1, wherein has a suppressing nonwoven flow permeation and reverse gas of the oil. The oil separator according to claim 1, wherein the backflow suppression portion is formed integrally with the oil separation portion. The oil separator according to claim 1 or 2, wherein the backflow suppressing portion is formed separately from the oil separating portion. The oil according to any one of claims 1 to 4 , further comprising a buffer space having a channel cross-sectional area larger than a channel cross-sectional area of the discharge opening, between the oil separation unit and the backflow suppressing unit. Separator.