JPH05231121A - Oil removing device for blow-by gas - Google Patents

Abstract

PURPOSE:To improve the separative catching faculty for the oil in a trapper by increasing the relative negative pressure in an oil reservoir chamber and increasing the flow rate and flow speed of the blow-by gas which flows in the cyclone oil trapper. CONSTITUTION:The position of a negative pressure taking-out port 91 of a negative pressure port 9 which communicates to an oil reservoir chamber 6 in a cyclone oil trapper 1 is set in a cyclone chamber inlet passage 23 which communicates to the cyclne chamber 3 in the cyclone oil trapper 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a cyclone oil trapper (centrifugal oil collector) which is an oil removing device for blow-by gas of an engine.

[0002]

2. Description of the Related Art Conventionally, in order to burn blow-by gas leaking from a combustion chamber into an engine crankcase without releasing it into the atmosphere, a PCV (Positive Cran) is used.
The blow-by gas is returned from the crankcase to the intake system by the kcase Ventilation system to reduce and re-burn the blow-by gas. At this time, there is oil mist (fog-like oil) in the blow-by gas in the crankcase, and it is inconvenient for re-combustion until then, and the oil consumption increases. Therefore, oil is separated from the blow-by gas and returned to the crankcase before the blow-by gas is returned to the intake system.

Various types of conventional oil removing devices have been devised and used. For example, Japanese Patent Laid-Open No. 3-74508 discloses various types of oil trappers, but many of them require an oil suction device such as a vacuum pump, and the device is complicated. .. Among them, the cyclone oil trapper 1 having the centrifugal oil separating device shown in FIG. 3 is mentioned as a device which does not require an oil suction device such as this pump.

FIG. 3 is a vertical sectional view of the cyclone oil trapper 1 attached to the cylinder head cover 14. In the figure, the blow-by gas G in the crankcase 15 is the blow-by gas inlet to the oil trapper 1. 2 into the cyclone chamber (centrifugal chamber) 3, rise in the central cyclone chamber outlet passage 4 while making a swirling motion, and pass through the blow-by gas outlet passage 11 and the blow-by gas outlet 8
It is introduced into the intake system. At this time, the centrifugal force of the swirling motion separates the oil L in the blow-by gas G,
The blow-by gas passes through the inner wall surface of the outlet passage 11 and accumulates in the annular groove 12 formed in the lower portion of the wall surface.
The oil flows into the oil sump chamber 6 and is stored therein. The collected oil L is collected in an oil pan (not shown) below the crankcase 15 when the oil discharge port 10 opens at a predetermined time.

At this time, since the negative pressure port 5 connects the cyclone chamber 3 and the oil sump chamber 6 and is located in the center of the cyclone chamber 3, the negative pressure port 5 is located near the upper end of the cyclone chamber 3 at the center of the swirling flow. Due to this, a relative negative pressure is generated in the cyclone chamber 3, and the air in the oil sump chamber 6 is sucked by this negative pressure, and the inside of the sump chamber 6 is cyclone oil trapper 1
A negative pressure is relatively generated inside the annular groove 12 due to this negative pressure.
The oil accumulated therein is sucked into the oil sump chamber 6 via the passage 7, and the separation of the oil is promoted. However, the mechanism that obtains the negative pressure by this swirling flow does not generate much negative pressure.

Cyclone oil trapper 1 shown in FIG.
Is an improvement of the device shown in FIG. 3 in order to further increase this negative pressure. In the figure, the same parts as those in FIG. 3 are designated by the same reference numerals. In the figure, 23 is the cyclone chamber inlet passage, and 13 is the oil discharge passage when the oil discharge outlet 10 is open. 2A is a vertical cross-sectional view of the cyclone oil trapper 1, and FIG. 2B is FIG.
It is a II-II sectional view of [a].

In FIG. 2, in order to further increase the negative pressure generated near the upper end of the negative pressure port 5 in the apparatus of FIG. 3, the lower end of the cyclone chamber outlet passage 4 is connected to the upper end of the negative pressure port 5. The portions are made close to each other so as to cover them, and the narrow gap between them is structured so that the swirling flow of the blow-by gas G rises at a high speed, whereby a suction action due to the flow of the blow-by gas G is generated, and a so-called flow venturi is obtained. A negative pressure due to the effect is generated at the upper end portion of the negative pressure port 5, and this negative pressure is added to the negative pressure generated at the central portion by the swirling flow, and a larger negative pressure is obtained.

[0008]

In the cyclone oil trapper 1 having the structure shown in FIG. 3, the size of the opening communicating with the cyclone chamber 3 from the cyclone chamber 3 to the cyclone chamber outlet passage 4 is not particularly limited. The flow rate of the blow-by gas G flowing can be sufficient, but the negative pressure generated in the negative pressure port is not so high because it is due to the swirling flow and is insufficient.

On the other hand, in the structure shown in FIG. 2, the negative pressure generated is higher than that in the former case, but on the other hand, since the inlet area to the cyclone chamber outlet passage 4 is narrowed due to the negative pressure port 5, The flow rate is narrowed and the flow rate flowing into the blow-by gas outlet passage 11 is reduced, and the amount of oil mist separated and collected in the annular groove 12 is reduced. In view of the above problems, in the present invention, a high negative pressure is obtained in the oil sump chamber 6 in order to facilitate suction and collection of oil in the oil sump chamber 6, and the blow-by The flow velocity of the gas in the cyclone oil trapper 1 is sufficiently increased to enhance the oil separation ability by centrifugal force.
It is intended to provide a higher performance cyclone oil trapper.

[0010]

To achieve the above object, the present invention provides a cyclone oil trapper having a blow-by gas inlet on the crankcase side of an engine and a blow-by gas outlet on the intake system side. A blow-by, characterized in that the position of the negative pressure outlet of the negative pressure port communicating with the oil reservoir chamber in the cyclone oil trapper is provided in the cyclone chamber inlet passage leading to the cyclone chamber in the cyclone oil trapper. A gas oil removing device is provided.

[0011]

[Operation] The blow-by gas flowing into the cyclone oil trapper through the blow-by gas inlet passage causes a suction effect due to the Venturi effect at the negative pressure outlet of the negative pressure port, so that the oil in the oil sump chamber is sucked in The interior of the oil trap has a relatively negative pressure. On the other hand, the blow-by gas flowing into the cyclone chamber through the cyclone chamber inlet passage rises in the cyclone chamber outlet passage while making a swirling motion, and the oil mist separated by the swirling motion in the blow-by gas outlet passage adheres to the wall surface of the passage. It descends, accumulates in the lower annular groove on the wall surface, and the inside of the passage leading to the oil sump chamber is sucked by the negative pressure of the oil sump chamber and descends to be collected in the oil sump chamber, thereby separating the oil from the blow-by gas. Sufficient collection.

[0012]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a drawing of an embodiment of the present invention, FIG. 1 [a] is a longitudinal sectional view of a cyclone oil trapper 1, and FIG. 1 [b] is FIG.
A sectional view taken along the line I-I of [a] is shown, and the portions common to those in FIG.

2 differs from FIG. 2 in that the negative pressure port 5 rising from the oil sump chamber 6 and opening to the cyclone chamber 3 is eliminated and a new blow-by gas outlet passage 11 is provided instead.
The negative pressure port 9 communicating with the oil sump chamber 6 is provided in the cyclone chamber inlet passage 23 having a smaller diameter. The other configurations are the same as those shown in FIG.

With the above structure, the blow-by gas G in the crankcase 15 enters the cyclone chamber 3 from the blow-by gas inlet 2 through the cyclone chamber inlet passage 23, in which the central cyclone chamber outlet passage is swirled. 4 is introduced into the intake system of the engine from the blow-by gas outlet 8 through the blow-by gas outlet passage 11.

At this time, in this example, since the negative pressure port 5 as shown in FIG. 2 is not provided in the cyclone chamber 3, there is no obstacle and the cyclone chamber outlet opening in the cyclone chamber 3 is eliminated. The blow-by gas G swirling due to the widening of the inlet opening of the passage 4 flows into the cyclone chamber outlet passage 4 much more smoothly than in the example of FIG. 2 and is introduced into the intake system. For this purpose, cyclone oil trapper 1
The amount of blow-by gas G sucked into the blow-by gas inlet 2 also increases, and the flow velocity and flow rate of the blow-by gas G flowing through the cyclone chamber inlet passage 23 increase. Therefore, the Venturi effect at the negative pressure outlet 91 of the negative pressure port 9 provided on the wall surface of the cyclone chamber inlet passage 23 is also enhanced, and a large amount of air in the oil sump chamber 6 passes through the negative pressure port 9 into the cyclone chamber inlet passage 23. And a high negative pressure is generated in the oil sump chamber 6.

As described above, the oil L that has risen while swirling in the blow-by gas outlet passage 11 together with the blow-by gas G and flows out is brought into contact with the wall surface of the blow-by gas outlet passage 11 by the centrifugal force and flows down. It collects in the annular groove 12 at the lower part of the wall surface, is further sucked by the high negative pressure of the oil storage chamber 6 and flows into the oil storage chamber 6 through the oil passage 7, where it is completely separated from the blow-by gas G and stored. Be done. The accumulated oil L is discharged from the oil outlet 1 at a predetermined time.
0 opens and goes through the oil discharge passage 13 to the crankcase 1
5 Collected in an oil pan (not shown) at the bottom.

As described above, the cyclone chamber 3 is larger than the conventional example.
Since the flow rate and flow velocity of the blow-by gas G flowing in and out of the tank are increased, and a higher negative pressure is obtained in the oil sump chamber 6 than in the conventional case, the separation and collection capability of the oil mist is increased and the performance is higher, and A cyclone oil trapper having a simple structure and compact structure can provide an oil removing device for blow-by gas.

[0018]

The following effects can be obtained by implementing the present invention. (1) By improving the negative pressure outlet of the oil trapper, the negative pressure in the oil storage chamber is increased, the flow rate and flow velocity of blow-by gas are also increased, and the separation and collection of oil from blow-by gas is efficient. Easy to do.

(2) Due to the above, it becomes easier for the blow-by gas to flow from the crankcase to the intake system,
The amount of outflow to the intake system is increased, and the reducing action of blow-by gas is promoted. (3) The device is relatively simple and compact, which is advantageous in terms of cost.

[Brief description of drawings]

FIG. 1 shows a cyclone oil trapper which is an embodiment of the present invention, FIG. 1 [a] is a longitudinal sectional view thereof, and [b] is [a].
FIG. 3 is a sectional view taken along line I-I of FIG.

FIG. 2 shows a cyclone oil trapper according to the prior art, FIG. 2 [a] is a longitudinal sectional view thereof, and [b] is II- of [a].
It is a II sectional view.

FIG. 3 shows a vertical sectional view of another example of a cyclone oil trapper according to the prior art.

[Explanation of symbols]

 1 ... Cyclone oil trapper 2 ... Blow-by gas inlet 3 ... Cyclone chamber 4 ... Cyclone chamber outlet passage 5, 9 ... Negative pressure port 6 ... Oil sump chamber 8 ... Blow-by gas outlet 11 ... Blow-by gas outlet passage 12 ... Annular groove 15 ... Crankcase 23 ... Cyclone chamber inlet passage 91 ... Negative pressure outlet G ... Blow-by gas L ... Oil

Claims (1)

[Claims] 1. A cyclone oil trapper (1) having an inlet (2) for blow-by gas on the crankcase (15) side of an engine and an outlet (8) for blow-by gas on the intake system side. Cyclone communicating the position of the negative pressure outlet (91) of the negative pressure port (9) communicating with the oil sump chamber (6) in the trumpet (1) with the cyclone chamber (3) in the cyclone oil trapper (1). An oil removing device for blow-by gas, which is provided in the chamber inlet passage (23).