JPH0227128Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the structure of an oil separator that separates blow-by gas and oil in a PCV system.

[Conventional technology] PCV that recirculates blow-by gas to the intake system
(Positive crankcase ventilation)
In the system, the path of blow-by gas is typically from the crankcase through the cam chamber to the intake system. Since the blow-by gas from the crankcase contains a large amount of oil mist, and a large amount of oil is scattered in the cam chamber, the oil must be separated from the blow-by gas before being sent to the intake system. No.

The oil separator that separates oil from this blow-by gas is usually installed in the head cover of the cam chamber, but various oil separator structures have been proposed in the past (for example, Utility Model Application No. 55-152313, Utility Model Application No. 56) -No. 149013, 1987
-2344, Utility Model No. 58-79009, Utility Model 58-
No. 108215, Utility Model Application Publication No. 59-94106).

[Problems to be solved by the invention] However, in many conventional oil separators, the blow-by gas intake port into the ventilation case of the oil separator also serves as the oil discharge port from the case. It was difficult for the oil to flow out of the case, and there was a risk that the oil cutting performance would not be fully demonstrated.

Also, inside the ventilation case,
Since the blow-by gas passage also served as an oil return passage in the direction opposite to the flow direction of the blow-by gas, there was a risk that the separated oil would not reach the oil discharge port smoothly. In particular, if the oil is not clearly separated from the blow-by gas flow at the end of the blow-by gas flow direction within the ventilation, there is a risk that a portion of the oil once separated may be carried away to the intake system with the blow-by gas flow again. There is. Regarding this point,
In the oil separator disclosed in Publication No. 108215, the oil return passage is branched from a position near the final part in the ventilation case, but the structure is such that the oil cannot be returned unless it is carried to the branching part. Since the flow direction of the blow-by gas and the flow direction of the oil are in the same direction up to the branching part, there is the problem that the separated oil is likely to get back into the flow of the blow-by gas, and the oil return passage is not a ventilation case. Since the oil separator is formed completely separately, there is a problem in that the overall size of the oil separator becomes significantly large.

As described above, if the oil cutting performance and oil separation performance are insufficient, the amount of oil carried away to the intake system increases accordingly, causing problems such as increased oil consumption and deterioration of exhaust purification performance.

Therefore, the present invention aims to efficiently improve the oil removal performance and oil separation performance within the ventilation case of the oil separator, and reduce the amount of oil entering the PCV system, without significantly increasing the size of the oil separator. purpose.

[Means for Solving the Problems] The oil separator of the PCV system of the present invention that meets this purpose divides the inside of the ventilation case of the oil separator provided in the PCV system into at least two chambers in the flow direction of blow-by gas. The blow-by gas path in the ventilation case and the oil return path in the ventilation case are completely separated, and a blow-by gas path in the flow direction of the blow-by gas is placed on the bottom of the chamber on the downstream side in the flow direction of the blow-by gas. An oil return groove is formed that slopes downward in the opposite direction, and the oil return groove is opened in the upstream chamber in the blow-by gas flow direction of the two chambers, and the opening direction is directed downwardly in the blow-by gas flow direction of the two chambers. The gas flow direction is defined by a blow-by gas intake port into the ventilation case and an oil discharge port which discharges oil from the oil return path to the outside of the ventilation case.

[Function] In the oil separator of such a PCV system, the blow-by gas inlet and the oil outlet are located at different locations, so the oil separated from the blow-by gas in the oil separator is separated from the incoming blow-by gas. is discharged freely without interfering with the flow of water.

In addition, the blow-by gas path and oil return path are completely separated within the ventilation case, so the oil separated from the blow-by gas flows smoothly in the opposite direction without going against the flow of the blow-by gas. It reaches the discharge port and is returned to the cam chamber.

Furthermore, of the at least two chambers formed in the ventilation, an oil return groove is provided on the bottom side of the chamber on the downstream side in the blow-by gas flow direction, and is inclined downward in the opposite direction to the blow-by gas flow direction. The oil separated near the final part inside the ventilation case is collected in this oil return groove and is effectively separated from the main stream of blow-by gas. Since the opening of this oil return groove to the upstream chamber is in the same direction as the flow direction of the blow-by gas in the chamber, the blow-by gas will not pass from the upstream chamber to the downstream chamber and cause a short circuit. The oil flowing down the oil return groove is not blocked by this opening, and the oil collected in the oil return groove is smoothly returned through a predetermined oil return path.

Therefore, good oil removal performance and oil separation performance in the ventilation case of the oil separator are ensured, and the amount of oil carried away to the intake system is reduced. Moreover, since the oil return path can be formed within the ventilation case while being completely separated from the blow-by gas path, the overall size of the oil separator can be suppressed from increasing in size.

[Embodiments] Hereinafter, preferred embodiments of the oil separator of the PCV system of the present invention will be described with reference to the drawings.

1 to 4 show an oil separator for a PCV system according to an embodiment of the present invention, which is applied to a double overhead camshaft engine. In Figure 1, 1
2 shows a head cover attached to the upper part of the cylinder head 2, 3 shows a camshaft on the intake manifold side, and 4 shows a camshaft on the exhaust manifold side. Inside the head cover 1,
The oil separator 5 of the PCV system is installed. The oil separator 5 serves as a ventilation case and is composed of two parts: an air cleaner side PCV path 6 that sends blow-by gas to the air cleaner, and an intake manifold side PCV path 7 that sends blow-by gas to the intake manifold.

The blow-by gas intake ports 8 and 9 of the oil separator 5 are formed from a plurality of holes 12 provided on the lower surfaces of the buff-full plates 10 and 11. The blow-by gas 13 is connected to the lower part of the blow-by gas intake ports 8, 9.
Guide plates 14 and 15 are provided to guide the camshafts 3 and 4, and the guide plates 14 and 15 are opened in a direction parallel to the camshafts 3 and 4. Note that the position of the lower surface of the blow-by gas intake ports 8 and 9 is at the center 1 of the camshaft shaft.
It is set higher than 6.

Hole 1 is provided at the top of blow-by gas intake ports 8 and 9.
An expansion chamber 17 is formed in which the blow-by gas 13 introduced from 2 is temporarily expanded. At the upper part of the downstream end of the expansion chamber 17, there is a weir 18 extending downward.
is provided, and the blow-by gas flow path is narrowed at the weir 18. On the lower surface side of the expansion chamber 17 and on the lower surface side of the weir 18 part, an oil discharge port 20 is provided at a position different from the hole 12 to allow the oil 19 to escape downward.
is formed.

The blow-by gas 13 that has passed through the expansion chamber 17 is
The blow-by gas is guided to the chamber 21 as a chamber on the upstream side in the flow direction, but the oil discharge port 2 of the chamber 21
The lower surface 22 near 0 is formed into an inclined surface in order to cause the oil 19 to flow down to the oil discharge port 20. The chamber 21 extends at right angles,
The passage lower surface 23 after being bent is formed into an inclined surface that rises in the flow direction of the blow-by gas 13.

At the upper part of the downstream end of the chamber 21, there is a hole 2 that communicates with the chamber 24.
5 is provided, and the blow-by gas 13 is connected to the hole 2.
5, the blow-by gas enters a chamber 24 as a chamber located downstream in the flow direction, changes the flow direction by 180 degrees, and flows inside the chamber 24. Therefore, chamber 24 is
It is located at the upper part of the chamber 21. An oil return groove 26 that slopes downward in a direction opposite to the flow direction of the blow-by gas 13 is formed on the lower surface of the chamber 24 , and the oil return groove 26 opens into the chamber 21 . This opening 26a opens in the same direction as the blow-by gas flow direction in the chamber 21. The lower surface 27 of the chamber 24 carries the oil 19 to the oil return groove 2.
The oil return groove 26 is formed into an inclined surface having a downward slope toward the oil return groove 26 so as to collect the oil in the oil return groove 26. room 2
A blow-by gas supply port to the intake system is provided at the downstream end of the ventilation case 6, which is connected to the air cleaner through a blow-by gas supply port 28, and a blow-by gas supply port from the ventilation case 7 is connected to the air cleaner. It is connected through a gas supply port 29 to a PCV valve connected to the intake manifold.

30, 31, 32, 33 in FIG. 2 indicate each member constituting the oil separator,
A lower member 30, a partition plate 31, a gasket 32, and an inner wall shape 33 of the head cover 1 are shown, respectively. Further, 34 in FIG. 4 indicates a plug tube.

The operation of the oil separator in the PCV system configured as described above will be explained below.

First, regarding the gas-liquid separation function of the oil separator 5, as shown in FIG.
The blow-by gas 13 guided by the blow-by gas inlets 4 and 15 flows into the expansion chamber 17 together with oil mist from the blow-by gas intake ports 8 and 9. In the expansion chamber 17, the flow path is rapidly expanded, so the flow velocity is temporarily lowered, and then increased by the restriction of the weir 18. The blow-by gas 13, which is a gas, smoothly follows the speed increase, but the oil 19, which is a liquid, does not follow the speed increase due to its inertia, and the oil 19 is separated from the blow-by gas 18. Also, the oil 1 that collided with the inner surface of the weir 18
9 also falls downward from the oil discharge port 20 and returns to the cam chamber and oil pan.

The blow-by gas 13 that has passed through the expansion chamber 17 is
As shown in FIG.
As the oil 19 flows down, the flow path is gradually narrowed and the speed is increased, and the oil 19 is separated. Since the lower surface of the chamber 21 is an inclined surface, the oil 19 separated here flows along the lower surface 23 and the lower surface 22 to the oil outlet 2.
It is guided to 0 and falls downward.

Furthermore, the blow-by gas 13 is led into the chamber 24 through the hole 25 and sent from the end of the chamber 24 to the intake system. Oil 19 separated in this chamber 24
is collected into the oil return groove 26 along the slope of the lower surface of the chamber, returned from the oil return groove 26 through the opening 26a into the chamber 21, and further flows to the inclined surfaces 23, 2.
2 to an oil outlet 20. Since the oil return groove 26 is located completely away from the main flow of blow-by gas in the chamber 24, the oil collected in the oil return groove 26 is completely separated from the flow of blow-by gas. When the oil in the oil return groove 26 returns to the chamber 21, since the opening 26a is in the same direction as the flow direction of the blow-by gas in the chamber 21, the blow-by gas in the chamber 21 is short-circuited from the opening 26a to the chamber 24. At the same time, the oil flowing down from the opening 26a is also prevented from being blocked by the flow of blow-by gas in the chamber 21, and the oil is returned smoothly.

In this way, when the blow-by gas 13 flows into the ventilation cases 6, 7, the inflow position and the oil discharge position are separated, so that the oil 19 from the oil discharge port 20 and the inflow blow-by gas 13 are separated. Interference is avoided and the separated oil is discharged freely without obstruction, improving oil cutting performance.

Further, the blow-by gas path inside the ventilation cases 6 and 7 is from the expansion chamber 17 to the chamber 21, the hole 25, the chamber 24, and the blow-by gas supply ports 28 and 29.
On the other hand, the oil return path runs from the chamber 24 to the oil return groove 26 along the slope of the lower surface.
The oil is collected from the oil return groove 16 to the chamber 21, the expansion chamber 17 along the lower surfaces 23 and 22 of the chamber 21, and the oil discharge port 20 on the lower surface of the expansion chamber 17. In this way, the oil 19 passes through the ventilation case in the opposite direction to the flow of the blow-by gas 13 and reaches the oil discharge port 20 through a path on the lower side of the passage that is completely separated from the main flow of the blow-by gas 13. reach. Therefore, the oil 19 separated from the blow-by gas 13 is smoothly guided to the oil discharge port 20 without interfering with the flow of the blow-by gas 13, and the oil draining performance and oil separation performance in the ventilation case are also improved. Improved.

[Effect of the invention] Therefore, according to the invention, the blow-by gas path and the oil return path in the oil separator are completely separated, and the blow-by gas flow direction downstream side of the two chambers partitioned in the ventilation case is By providing an oil return groove inside the chamber and smoothly returning the oil collected in the oil return groove through the opening of the oil return groove and the oil return path, the oil draining performance and oil separation performance of the oil separator are greatly improved. This reduces the amount of oil entering the PCV system, resulting in reduced oil consumption and improved exhaust purification performance.

[Brief explanation of the drawing]

Fig. 1 is a partial perspective view of an oil separator of a PCV system according to an embodiment of the present invention, Fig. 2 is an exploded perspective view of the oil separator of Fig. 1, and Fig. 3 is an enlarged view taken along the - line in Fig. 1. The sectional view, FIG. 4, is an enlarged partial sectional view taken along the - line in FIG. 1. 1... Head cover, 3, 4... Camshaft, 5... Oil separator, 6, 7... Ventilation case, 8, 9... Blow-by gas intake, 10, 11... Bumpy plate, 12...
...hole, 13...blow-by gas, 14,15...
Information board, 17... Expansion room, 18... Cough, 19...
...Oil, 20...Oil discharge port, 21, 24...
...Chamber, 22, 23...Bottom surface of chamber, 25...Hole, 26
... Oil return groove, 26a ... Opening, 27 ... Chamber lower surface, 28, 29 ... Blow-by gas supply port.

Claims (1)

[Scope of utility model registration request] The inside of the ventilation case of the oil separator provided in the PCV system is divided into at least two chambers in the flow direction of the blow-by gas, and the blow-by gas path inside the ventilation case and the oil return path inside the ventilation case are divided into at least two chambers in the flow direction of the blow-by gas. An oil return groove is formed on the bottom of the two chambers on the downstream side in the flow direction of the blowby gas, and the oil return groove is inclined downward in the direction opposite to the flow direction of the blowby gas. It opens into the chamber on the upstream side of the chamber in the blow-by gas flow direction, the opening direction is the flow direction of the blow-by gas in the upstream chamber, and the blow-by gas intake port into the ventilation case and the oil return. An oil separator for a PCV system that is characterized by a separate oil discharge port for discharging oil from the passage to the outside of the ventilation case.