JP2015151890A - Cyclone type oil separation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cyclone type oil separation device in which the reverse flow of oil from an oil discharge part can be suppressed.SOLUTION: A cyclone type oil separation device 3 separates oil from blow-by gas with the swirl of the blow-by gas in a conical oil separation chamber 10 having a diameter gradually smaller as extending to the vertically lower side, and discharges the separated oil from an oil discharge part 11 provided on the vertically lower side. The cyclone type oil separation device 3 includes a valve chest 12 provided between the oil separation chamber 10 and the oil discharge part 11, an opening part 13 communicating the valve chest 12 and the oil separation chamber 10 with each other, and a check valve 16 comprised of a plate-like valve element 14 and a valve stem 15 extending from the valve element 14. The diameter of the valve element 14 of the check valve 16 is larger than an inner diameter D1 of the opening part 13, while the diameter of the valve stem 15 thereof is smaller than the inner diameter D1 of the opening part 13. The valve element 14 is housed in the valve chest 14 while the valve stem 15 is inserted into the opening part 13.

Description

  The present invention relates to a cyclone type oil separation device that rotates blowby gas to separate oil contained in the blowby gas.

  The blow-by gas leaking from the combustion chamber of the internal combustion engine into the crank chamber is returned to the intake passage through the blow-by gas recirculation passage that connects the crank chamber and the intake passage. Blow-by gas contains oil scattered in the crank chamber. For this reason, in the conventional internal combustion engine, the oil is separated by the oil separation device provided in the blow-by gas recirculation passage, and then the blow-by gas is recirculated to the intake passage (for example, Patent Document 1).

  Patent Document 1 discloses a cyclonic oil separation device that rotates a blow-by gas and centrifuges oil contained in the blow-by gas. The oil separated from the blow-by gas by this device is discharged from an oil discharge portion provided at the lower end of the device and returned to the crank chamber.

JP 2013-217285 A

  By the way, depending on the engine operating state, an excessive negative pressure may be generated in the intake passage. When such a negative pressure acts on the cyclone type oil separation device through the blow-by gas recirculation passage, the oil is sucked up from the oil discharge portion, and there is a possibility that the oil flows back into the device.

  This invention is made | formed in view of such a subject, The objective is to provide the cyclone type oil separator which can suppress the backflow of the oil from an oil discharge part.

  A cyclone type oil separation device for solving the above-mentioned problems is a separated oil by rotating blowby gas in a conical oil separation chamber whose diameter is reduced downward in the vertical direction to separate oil contained in the blowby gas. Is discharged from an oil discharge portion provided vertically below. The oil separation device includes a valve chamber provided between an oil separation chamber and an oil discharge portion, an opening communicating the valve chamber and the oil separation chamber, a plate-like valve body, and a valve extending from the valve body. And a check valve made of a rod. The check valve has a diameter of the valve body larger than the inner diameter of the opening, while the diameter of the valve stem is smaller than the inner diameter of the opening, and the valve body is in a state where the valve rod is inserted into the opening. It is housed in the room.

  In the above-described configuration, a check valve is provided that includes a plate-like valve body housed in the valve chamber and a valve rod extending from the valve body and inserted through the opening. For this reason, when the negative pressure acting on the cyclone type oil separator is large, the check valve is sucked up to the opening side. Since the diameter of the valve body of the check valve is larger than the inner diameter of the opening, when the check valve is sucked up in this way, the opening is closed by the valve body of the check valve. Therefore, according to the said structure, it can suppress that an oil flows back into a cyclone type oil separator from an oil discharge part.

  Since the diameter of the valve rod of the check valve inserted through the opening is smaller than the inner diameter of the opening, when the check valve is not sucked up and the opening is not closed by the valve body, Oil separated from blow-by gas in the separation chamber can be discharged to the valve chamber through the gap between the opening and the valve stem and discharged from the oil discharge portion.

A sectional view showing typically composition of a PCV case provided with a cyclone type oil separation device of one embodiment. It is a figure which shows the structure of the non-return valve in the embodiment, (a) is a side view of a non-return valve, (b) is a top view of a non-return valve. Sectional drawing which shows the state of a non-return valve when the opening part is not obstruct | occluded in the embodiment. Sectional drawing which shows the state of a non-return valve when the opening part is obstruct | occluded in the embodiment.

Hereinafter, an embodiment of a cyclonic oil separator will be described with reference to FIGS.
A PCV case including a PCV (Positive Crankcase Ventilation) valve is provided in the blow-by gas recirculation passage that communicates the crank chamber with the intake passage.

  As shown in FIG. 1, the PCV case 1 is provided with a labyrinth-type oil separation device 2 that separates oil from the blow-by gas by meandering the blow-by gas and a cyclone-type oil separation device 3.

  The labyrinth oil separation device 2 is provided with an inflow hole 4 through which blow-by gas flows and a plurality of ribs 5. In the apparatus 2, a meandering chamber 6 and an expansion chamber 7 partitioned by ribs 5 are provided. In the meandering chamber 6, a meandering passage for allowing the blow-by gas to meander by a plurality of ribs 5 is formed. The expansion chamber 7 has a relatively large volume, and increases the volume of the blow-by gas that has flowed in to decrease the flow velocity. Therefore, when blow-by gas flows into the labyrinth type oil separation device 2, when the blow-by gas meanders and flows in the meandering chamber 6, oil contained in the blow-by gas collides with and adheres to the rib 5. When blow-by gas flows into the expansion chamber 7, the flow rate of the blow-by gas decreases, and the oil contained in the blow-by gas falls due to its own weight. As a result, oil is separated from blow-by gas. The separated oil flows down along the ribs 5 and returns to the crank chamber from the oil discharge hole 8 provided in the PCV case 1.

  Further, the labyrinth oil separation device 2 and the cyclone oil separation device 3 are communicated with each other through a communication portion 9. For this reason, the blow-by gas that has passed through the labyrinth oil separation device 2 then flows into the cyclone oil separation device 3.

  The cyclonic oil separation device 3 is provided with a conical oil separation chamber 10 whose diameter is reduced toward the lower side in the vertical direction (lower side in FIG. 1). In the oil separation chamber 10, the blow-by gas is swirled to centrifuge the oil contained in the blow-by gas. An oil discharge part 11 for discharging oil from the apparatus 3 is provided at the lower end in the vertical direction of the apparatus 3. A valve chamber 12 is provided between the oil separation chamber 10 and the oil discharge portion 11, and the valve chamber 12 and the oil separation chamber 10 communicate with each other through an opening 13. Therefore, the oil separated from the blow-by gas by the oil separation chamber 10 flows into the valve chamber 12 through the opening 13 and is discharged from the oil discharge portion 11 through the valve chamber 12. The oil thus discharged is returned to the crank chamber from an oil discharge hole 8 provided in the PCV case 1.

  The cyclone oil separator 3 is provided with a check valve 16 including a valve body 14 and a valve rod 15 extending from the valve body 14. The valve body 14 is accommodated in the valve chamber 12, and the valve rod 15 is inserted through the opening 13. The opening of the opening 13 is substantially circular, and the inner diameter of the opening 13 is D1 as shown in FIG.

Next, the configuration of the check valve 16 will be described in detail with reference to FIG.
As shown in FIGS. 2A and 2B, the valve body 14 of the check valve 16 has a substantially circular plate shape. A cylindrical valve rod 15 extending vertically from the valve body 14 is provided at the center of the valve body 14. The diameter D2 of the valve body 14 is larger than the inner diameter D1 of the opening 13, while the diameter D3 of the valve stem 15 is smaller than the inner diameter D1 of the opening 13.

  As shown in FIG. 1, the blow-by gas that has passed through the cyclone type oil separation device 3 is discharged from a gas discharge unit 17 provided vertically above the device 3 (upward in FIG. 1), and is taken in through a PCV valve 18. Returned to the aisle. Note that the PCV valve 18 can discharge blow-by gas into the intake passage while preventing a reverse flow of intake air by using the negative pressure of the intake passage.

Next, with reference to FIG.3 and FIG.4, the effect | action of the cyclone type oil separation apparatus 3 of this embodiment is demonstrated.
Depending on the engine operating state, an excessive negative pressure may be generated in the intake passage, and such a negative pressure acts in the PCV case 1 when the PCV valve 18 is open.

  As shown in FIG. 3, when the negative pressure acting on the PCV case 1 is not so large, that is, when the negative pressure acting on the cyclonic oil separator 3 is not so great, the check valve 16 is placed in the valve chamber 12. The valve body 14 and the opening 13 are separated from each other. In such a state, the valve stem 15 extending from the valve body 14 is maintained in a state of being inserted into the opening 13, but the diameter D3 of the valve stem 15 is smaller than the inner diameter D1 of the opening 13, A gap is formed between the valve stem 15 and the valve stem 15. Further, since the valve rod 15 is maintained in the state of being inserted through the opening portion 13, the position shift of the check valve 16 in the valve chamber 12 is suppressed.

  On the other hand, as shown in FIG. 4, when an excessive negative pressure is generated in the intake passage and the negative pressure acting on the cyclone type oil separation device 3 is large, the check valve 16 is sucked up to the opening 13 side. Since the diameter D2 of the valve body 14 of the check valve 16 is larger than the inner diameter D1 of the opening 13, when the check valve 16 is sucked up in this way, the opening 13 is closed by the valve body 14 of the check valve 16. . Further, since the valve stem 15 is maintained in a state of being inserted through the opening portion 13, when the check valve 16 is sucked up in this way, the valve stem 15 functions as a guide, and a predetermined position of the opening portion 13 is obtained. The valve body 14 comes into contact with the valve. Therefore, the opening 13 is more reliably closed. In addition, when a spherical valve body is adopted as such a check valve, the valve body and the opening are in line contact. On the other hand, in this embodiment, since the plate-shaped valve body 14 is employ | adopted, in the state which the valve body 14 obstruct | occluded the opening part 13, the valve body 14 and the opening part 13 surface-contact. Therefore, compared with the case where a spherical valve body is employed, the contact area between the valve body 14 and the opening 13 can be increased, and the area of the seal surface can be increased.

  Further, since the check valve 16 is accommodated in the valve chamber 12 different from the oil separation chamber 10, the rotation of the blow-by gas in the oil separation chamber 10 is hindered by providing the check valve 16. Is suppressed.

According to the embodiment described above, the following effects can be obtained.
(1) A check valve 16 including a plate-like valve body 14 accommodated in the valve chamber 12 and a valve rod 15 extending from the valve body 14 and inserted through the opening 13 is provided. While D2 was made larger than the inner diameter D1 of the opening 13, the diameter D3 of the valve stem 15 was made smaller than the inner diameter D1 of the opening 13. For this reason, when the negative pressure acting on the cyclone oil separator 3 is large, the opening 13 is closed by the valve body 14 of the check valve 16, and the oil flows back from the oil discharge part 11 into the cyclone oil separator 3. Can be suppressed. Further, when the opening 13 is not closed by the valve body 14, the oil can be discharged from the oil separation chamber 10 to the valve chamber 12 through the gap between the opening 13 and the valve rod 15.

  (2) Since the contact area between the valve body 14 and the opening 13 can be increased and the area of the sealing surface can be increased as compared with the case where a spherical valve body is employed, the case where a spherical valve body is employed As a result, it is possible to effectively prevent the oil from flowing back from the oil discharge portion 11 into the cyclone type oil separation device 3.

  (3) Since the check valve 16 is housed in the valve chamber 12 different from the oil separation chamber 10, the check valve 16 hardly inhibits the blow-by gas from turning in the oil separation chamber 10, and the oil contained in the blow-by gas. Can be effectively separated.

In addition, the said embodiment can be changed and implemented as follows.
In the above embodiment, an example in which the cross-sectional shapes of the valve body 14 and the valve stem 15 are substantially circular has been described. However, as long as the opening 13 can be opened and closed, these shapes can be changed as appropriate. .

  In the above embodiment, even when the opening 13 is not closed, the valve rod 15 is maintained in a state of being inserted through the opening 13, but such a configuration may be omitted. . That is, the valve stem 15 does not always have to be inserted through the opening 13.

  In the above embodiment, the cyclone type oil separation device 3 is provided in the PCV case 1, but the cyclone type oil separation device 3 only needs to be provided in the blow-by gas recirculation passage. A cyclone type oil separation device 3 may be provided.

  In the above embodiment, an example in which one cyclonic oil separation device 3 is provided has been described, but two or more such devices 3 may be provided.

  DESCRIPTION OF SYMBOLS 1 ... PCV case, 2 ... Labyrinth type oil separator, 3 ... Cyclone type oil separator, 4 ... Inflow hole, 5 ... Rib, 6 ... Serpentine chamber, 7 ... Expansion chamber, 8 ... Oil discharge hole, 9 ... Communication part DESCRIPTION OF SYMBOLS 10 ... Oil separation chamber, 11 ... Oil discharge part, 12 ... Valve chamber, 13 ... Opening part, 14 ... Valve body, 15 ... Valve rod, 16 ... Check valve, 17 ... Gas discharge part, 18 ... PCV valve

Claims (1)

A blow-by gas is swirled in a conical oil separation chamber whose diameter is reduced in the downward direction in the vertical direction to separate the oil contained in the blow-by gas, and the separated oil is discharged from an oil discharge portion provided in the lower direction in the vertical direction. A cyclonic oil separator,
A valve chamber provided between the oil separation chamber and the oil discharge portion;
An opening communicating the valve chamber and the oil separation chamber;
A check valve comprising a plate-like valve body and a valve rod extending from the valve body,
In the check valve, the diameter of the valve body is larger than the inner diameter of the opening, while the diameter of the valve rod is smaller than the inner diameter of the opening, and the valve rod is inserted into the opening. The cyclone type oil separation device in which the valve body is accommodated in the valve chamber.