JP3373968B2 - Oil trapper for internal combustion engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil trapper for an internal combustion engine, and more particularly to a cyclone type oil trapper which is supplied to a blowby gas reducing device to separate oil mist in blowby gas.

[0002]

2. Description of the Related Art In a crankcase of an internal combustion engine, blow-by gas leaking from the combustion chamber exists, and the gas component thereof causes deterioration of engine oil and the like. A blow-by gas reduction device that burns is used. This device is, for example, a shield system that connects a crankcase and an air cleaner with a hose, and a PCV (Positive Crankcase Ven).
tilation: That is, forced ventilation of the crankcase) The PCV system communicates the crankcase with the intake system via a valve and forcibly ventilates the crankcase while controlling the flow rate of blow-by gas by negative intake pressure.

Since the blow-by gas contains an oil mist in which the engine oil is atomized, it is not suitable for re-combustion as it is, and the engine oil consumption increases. Therefore, it is necessary to separate the oil mist in the blow-by gas before returning the blow-by gas to the intake system, and an oil drop separating device called an oil trapper, an oil separator, or the like is provided. As such an oil trapper, various types are known, but an external oil trapper (shown in FIG. 7) mounted on the outside of an engine block and a built-in oil trapper housed in a cylinder head cover. A type of oil trapper (not shown) is known.

As the above oil trapper, a so-called cyclone type trapper is widely used. This is configured, for example, as shown in FIG. 7, in which blow-by gas is introduced from the inlet port IP into the cyclone chamber (centrifugal chamber) CC, and is swirled to the outside through the central outlet passage OP. It is discharged and sucked into the intake system of the internal combustion engine. At this time, the oil mist in the blow-by gas is separated by the centrifugal force generated during the swirling motion and is collected in the oil sump chamber along the wall surface of the cyclone chamber.

[0005]

However, even in the above oil trapper, when the blow-by gas is discharged through the outlet passage, the oil attached to the outer wall of the outlet passage is caught in the inner wall of the outlet passage, It is observed that the swirling flow of blow-by gas in the outlet passage mixes with the blow-by gas and sucks it into the intake system as it is.

Therefore, an object of the present invention is to provide a cyclone type oil trapper for an internal combustion engine which can reliably separate oil mist with a simple structure.

[0007]

In order to achieve the above object, an oil trapper for an internal combustion engine according to the present invention has a first cylindrical body having a cylindrical surface inside and defining a first separation chamber. , The first
A second tubular body having one open end opened inside the second tubular body and the other open end open outside the first tubular body; and a second tubular body near the one open end of the second tubular body. an inlet port for the formed in the first cylindrical member so as to open in the tangential direction of the cylindrical surface, said second cylindrical body around in the first cylindrical external, communicates
A second separation chamber that communicates with the first cylindrical body through a through hole is defined, and the first separation chamber is defined by one of the first cylindrical bodies.
While directly communicating with the outside of the first cylindrical body from the opening end side ,
The first cylinder is configured to communicate with the outside of the first cylinder from the other open end side through the communication hole and the second separation chamber.

In the oil trapper for an internal combustion engine,
The second separation chamber is divided into the first separation chamber by the first cylinder body.
It may be configured so as to be integrally formed with the separation chamber.

[0009]

Thus, in the oil trapper for an internal combustion engine of the present invention, the inlet port is communicatively connected to, for example, the crankcase of the internal combustion engine, and the other open end of the second cylinder is the intake air of the internal combustion engine. Connected to the system. As a result, the blow-by gas in the crankcase is introduced tangentially from the inlet port into the first separation chamber, and is discharged from one opening end of the second tubular body toward the other opening end of the second tubular body while performing a swirling motion. , Sucked into the intake system of the internal combustion engine. Due to the swirling motion at this time, centrifugal force is applied to the oil mist in the blow-by gas, and the oil mist is separated along the inner wall surface of the first separation chamber, and most of the separated oil comes from one opening end side of the first cylindrical body. Directly discharged to the outside of the first cylindrical body. Further, when the blow-by gas is discharged from one opening end of the second cylinder toward the other opening end, the separated oil adhering to the outer wall of the second cylinder is entangled in the inner wall side and becomes blow-by gas. when mixed, the oil is further separated in a second separation chamber, a first
It is discharged to the outside of the first cylinder from the other open end side of the cylinder.
The separated oil thus discharged to the outside of the first cylinder can be separately returned to the internal combustion engine.

In the oil trapper for an internal combustion engine according to claim 2, since the second separation chamber is integrally formed with the first separation chamber by the first cylindrical body, it is basically the first separation chamber.
And the second cylinder can be configured by combining two parts.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of an oil trapper for an internal combustion engine of the present invention will be described below with reference to the drawings. 1 to 3 relate to an embodiment of the present invention and show a cyclone type oil trapper with an external engine block. As shown in FIG. 3, for example, two parts made of synthetic resin are combined.
That is, a state in which the main body 1 includes the first tubular body according to the present invention and the outlet pipe 2 including the second tubular body according to the present invention, and a part of the outlet pipe 2 is accommodated in the main body 1. Both are joined by.

The main body 1 is a substantially cylindrical body, one opening end 1a having a small diameter and the other opening end 1b having a large diameter, and a taper portion 1c formed on the opening end 1a side. A step portion 1d is formed in the middle of the main body 1. Furthermore, the main body 1
The opening end 1b of the main body 1 is formed with a flange portion 1f extending in the radial direction.
Are formed. The communication passage 3 communicates with the inside of the main body 1 through a communication hole 1e formed on the side of the main body 1 on the opening end 1b side, and the axial end surface is closed by the lid 4 on the opening end 1a side. It is formed so as to communicate with the outside through the lateral communication hole 1h. In addition, the opening end 1 near the step 1d
An inlet pipe 5 is formed integrally with the main body 1 on the a side, and an inlet port 5a is opened in the tangential direction of the inner cylindrical surface of the main body 1.

On the other hand, as shown in FIGS. 2 and 3, the outlet pipe 2 has a cylindrical separating portion 2a and an outlet portion 2b which are connected to each other through a pair of connecting portions 2c and 2c, and each has a collar. Part 6,
7 is integrally formed. In other words, the pair of communication holes 2 are provided between the connecting portions 2c, 2c forming a part of the cylindrical body.
e, 2e are formed. One of the collar portions 6 is fitted inside the main body 1 and is joined to the step portion 1d via the O-ring 8.
The other flange portion 7 has a flange portion 7f, which is in close contact with and joined to the flange portion 1f of the main body 1. The upper surface of the collar portion 6 is a tapered surface 6a as shown in FIG.
Is joined to the end surface of the communication hole 1e (substantially flush with the end surface if necessary), a smooth surface is formed from the outside of the communication hole 2e of the outlet pipe 2 to the communication passage 3.

When the outlet pipe 2 is joined to the main body 1 via the O-ring 8, the first separation chamber 11 is defined on the open end 1a side of the main body 1, and the main body 1 and the outlet are connected. A second separation chamber 12 is defined between the pipe 2 and the first separation chamber 11 via an inlet port 5a and an outlet pipe 2, and a crankcase (not shown) and an intake system (Fig. (Not shown), and communicates directly with the outside through the opening end 1a, and also from the opening end 1b side to the communication hole 2e, the second separation chamber 12,
It is configured to communicate with the outside via the communication passage 3 and the communication hole 1 h .

In the oil trapper of this embodiment having the above-mentioned structure, the inlet pipe 5 is connected to the crankcase of the internal combustion engine, and the outlet portion 2b of the outlet pipe 2 is connected to the intake system of the internal combustion engine. It Then, the blow-by gas in the crankcase is tangentially introduced into the first separation chamber 11 from the inlet port 5a, and is discharged from the separation portion 2a of the outlet pipe 2 to the outlet portion 2b while performing a swirling motion in the same. It is sucked into the intake system of the internal combustion engine. Due to the swirling motion at this time, centrifugal force is applied to the oil mist in the blow-by gas, the oil mist is separated along the inner wall surface of the first separation chamber 11, and the separated oil is discharged downward from the opening end 1a. Further, when the blow-by gas is discharged from the separating portion 2a of the outlet pipe 2 in the direction of the outlet portion 2b, the separated oil adhering to the outer wall of the separating portion 2a is caught in the inner wall side and mixed into the blow-by gas. Is introduced into the second separation chamber 12 from the communication hole 2e by the weak swirling flow of the blow-by gas in the separation portion 2a and separated from the gas, and the separated oil is the tapered surface 6a of the collar portion 6,
It is discharged to the outside through the communication hole 1e, the communication passage 3, and the communication hole 1h. The separated oil thus taken out is returned to the oil pan (not shown) via, for example, a rubber hose (not shown).

The lower open end 1a of the main body 1 and the communication passage 3
When the lower open ends of the two are provided close to each other, a flow from the former to the latter occurs, and the separated oil is returned to the outlet pipe 2 via the communication passage 3. In order to prevent this, a lid 4 is provided in this embodiment, and the communication passage 3 is provided with a communication hole 1h (and, if necessary, a hose (not shown)).
Although it is configured to communicate with the outside, the invention is not limited to this, and another means may be used as long as it is a means for blocking the flow from the open end 1a to the communication passage 3. For example, rubber hoses may be connected to the open end 1a and the communication passage 3, and the tips of these rubber hoses may be connected to an oil pan.

Further, regarding the outlet pipe 2 in this embodiment,
As shown in FIG. 6, the connecting portion 2c may be inclined with respect to the axial direction of the outlet pipe 2 so that the oil separation end face for the swirling flow of the gas in the outlet pipe 2 becomes long.

4 and 5 relate to another embodiment of the present invention and show a cyclone type oil trapper with a built-in cylinder head cover. In this embodiment, for example, four parts made of synthetic resin are combined, and a main body 21 that constitutes the first cylinder according to the present invention, a separation tube 22 that constitutes the second cylinder according to the present invention, The outlet pipe 23 is connected to the outlet pipe 23, and a housing 24 for accommodating the outlet pipe 23 and defining the second separation chamber according to the present invention.

The main body 21 is formed by integrally joining a tapered portion 21c having a small diameter opening 21a formed at the bottom and a cylindrical body portion 21d having a large diameter opening end 21b. 24, the inlet port 25a is opened in the tangential direction of the inner cylindrical surface of the body portion 21d. The housing 24 is a bottomed tubular body, the opening end 24b is formed to extend in the axial direction of the opening end 21b of the main body 21, and the communication passage 24a is expanded between the outer surface of the main body 21 and the axis in parallel. The discharge port 24c is formed at the bottom. A check valve 28 that opens and closes the discharge port 24c is provided outside the housing 24.

The separation tube 22 comprises a tapered cylindrical body functioning as a separation portion and a flange portion 26 integrally formed in the vicinity of the large-diameter end thereof. The flange portion 26 is the opening end 21b of the main body 21.
Is intimately joined to. The outlet pipe 23 is a bent pipe body as shown in FIGS. 4 and 5, and has a cylindrical outlet portion 23b having an outer diameter smaller than the inner diameter of the large diameter end of the separation pipe 22.
And a connection portion 23c integrally connected to the connection portion 23c, and a flange portion 27 is integrally formed near the opening end of the outlet portion 23b. The collar portion 27 is in close contact with and joined to the opening end 24b of the housing 24. As a result, the outlet 23
The open end of b is accommodated in the separation pipe 22, and an annular communication hole 29 is formed between them.

Thus, the first separation chamber 31 is defined within the main body 21, and the second separation chamber 32 is defined between the collar portion 26 and the collar portion 27 in the housing 24, and An oil reservoir 33 is defined between the bottom surface of the housing 24 and the main body 21. The first separation chamber 31 communicates with the second separation chamber 32 through the communication hole 29, and also communicates with the inside of the oil reservoir chamber 33 through the opening end 21a, and the second separation chamber 32 communicates with the communication passage 24a. It communicates with the inside of the oil sump chamber 33 via.

The oil trapper of this embodiment having the above structure is housed in a cylinder head cover (not shown), the inlet pipe 25 is located in the cylinder head cover, and the connecting portion 23c of the outlet pipe 23 is an internal combustion engine. Is connected to an intake system (not shown). Then, the blow-by gas introduced into the cylinder head from the crankcase is introduced tangentially into the first separation chamber 31 from the inlet port 25a, and is discharged from the separation pipe 22 to the outlet pipe 23 while performing a swirling motion. It is sucked into the intake system of the internal combustion engine. Due to the swirling motion at this time, centrifugal force is applied to the oil mist in the blow-by gas, the oil mist is separated along the inner wall surface of the first separation chamber 31, and the separated oil is discharged from the opening end 21a to the oil storage chamber 33. Further, when the blow-by gas is discharged from the separation pipe 22 toward the outlet pipe 23, the separation oil adhering to the outer wall of the separation pipe 22 is caught in the inner wall side and mixed into the blow-by gas. Is introduced into the second separation chamber 32 via and is separated from the gas.

On the other hand, since the vicinity of the lower open end 21a of the main body 1 is located at the center of the swirling flow in the first separation chamber 31, a negative pressure is relatively generated. Due to this negative pressure, the separation oil in the second separation chamber 32 is sucked downward through the communication passage 24a and is stored in the oil reservoir chamber 33 together with the separation oil discharged from the opening end 21a. Then, the check valve 28 opens according to the relationship between the pressure of the blow-by gas acting on the check valve 28 from the outside of the housing 24 and the weight of the separated oil in the oil reservoir 33, and the check valve 28 opens from the discharge port 24c. It is discharged into the cylinder head cover.

[0024]

Since the present invention is configured as described above, it has the following effects. That is, the oil trapper for an internal combustion engine of the present invention defines, around the second cylinder outside the first cylinder, a second separation chamber communicating with the first cylinder through the communication hole. , Open the first separation chamber to one of the first cylinders.
While communicating with the outside of the first cylinder directly from the mouth end side ,
Since it is configured to communicate with the outside from the other open end side of the cylindrical body through the communication hole and the second separation chamber, it is possible to form a small size with a small number of parts and reliably separate the oil mist. can do.

According to the oil trapper for the internal combustion engine of the second aspect, the oil trapper can be composed of two parts,
Manufacture and assembly become easier.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an oil trapper for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is an exploded perspective view of an oil trapper for an internal combustion engine according to an embodiment of the present invention.

FIG. 4 is a plan view of an oil trapper for an internal combustion engine according to another embodiment of the present invention.

FIG. 5 is a vertical sectional view of an oil trapper for an internal combustion engine according to another embodiment of the present invention.

FIG. 6 is a perspective view in which both ends of the outlet pipe are cut away to show another embodiment of the connecting portion of the outlet pipe in the embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of a conventional cyclone type oil trapper.

[Explanation of symbols]

1 main body (first cylinder) 2 Outlet pipe (second cylinder) 3 passages 4 Lid 5 inlet pipe 6,7 Tsubabe 8 O-ring 11 First separation room 12 Second separation chamber 21 body 22 Separation tube 23 Outlet pipe 24 housing 25 inlet pipe 26,27 Tsuba 28 Check valve 29 communication holes 31 First separation chamber 32 Second separation chamber 33 Oil reservoir

Continuation of the front page (56) Reference JP-A-2-294510 (JP, A) JP-A-3-74508 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01M 13 / 04 H01M 11/08

Claims (2)

(57) [Claims] 1. A first cylindrical body having a cylindrical surface inside and defining a first separation chamber; one opening end of the first cylindrical body opened; and the other opening end of the first cylindrical body. A second cylindrical body arranged so as to open to the outside of the cylindrical body, and formed in the first cylindrical body so as to open in the tangential direction of the cylindrical surface in the vicinity of one opening end of the second cylindrical body. An inlet port is provided, and the first cylindrical body is provided outside the first cylindrical body around the second cylindrical body through a communication hole.
A second separation chamber communicating with the inside is defined, and the first separation chamber is directly communicated with the outside of the first cylinder from one open end side of the first cylinder, and the first separation chamber is communicated with the first separation chamber . The other opening of the cylinder
An oil trapper for an internal combustion engine, which is configured to communicate with the outside of the first cylindrical body from the end side through the communication hole and the second separation chamber. 2. The oil trapper for an internal combustion engine according to claim 1, wherein the second separation chamber is integrally formed with the first separation chamber by the first cylindrical body.