CN114929996A

CN114929996A - Oil separator comprising a fresh air chamber

Info

Publication number: CN114929996A
Application number: CN202080091833.7A
Authority: CN
Inventors: J-P·卡迪纳尔; T·维尼齐亚尼
Original assignee: Renault SAS; Nissan Motor Co Ltd
Current assignee: Renault SAS; Nissan Motor Co Ltd
Priority date: 2019-12-02
Filing date: 2020-11-10
Publication date: 2022-08-19
Also published as: EP4069951B1; KR20220104732A; WO2021110369A1; EP4069951A1; FR3103856B1; FR3103856A1

Abstract

The invention relates to an oil separator (10) for an internal combustion engine (2) intended to be arranged on a cylinder block (3), the oil separator (10) comprising: a chamber (20); an inlet (21) formed in the chamber (20) intended to allow the entry of fresh air (F); and an outlet (22) formed in the chamber (20) intended to deliver fresh air (F) into the cylinder block (3), in particular into a lower portion of the crankcase (4), to evacuate blowby gases and/or oil vapours (BB) from such a cylinder block (3).

Description

Oil separator comprising a fresh air chamber

Technical Field

The present invention relates to an oil separator for an internal combustion engine. The invention also relates to an internal combustion engine comprising such an oil separator. The invention finally relates to a vehicle comprising such an internal combustion engine and/or such an oil separator.

Background

During combustion in an internal combustion engine, exhaust gases escape from the combustion chamber to the cylinder block. Therefore, such gas leakage causes gas to exist in the cylinder block. These gases are commonly referred to as blow-by or blow-by gases.

Accordingly, internal combustion engines typically include means for circulating these blowby gases to remove them from the cylinder block to an oil separator. In particular, a ventilation duct is generally provided which connects the air intake duct of the internal combustion engine to the cylinder block, in order to convey fresh air to the cylinder block.

However, incorporating such a vent tube into a very compact engine compartment is a complex task in the area of the cylinder block that is optimized in shape.

Description of the invention

The object of the present invention is to provide an oil separator which overcomes the above-mentioned disadvantages, in particular without disturbing surrounding components of the internal combustion engine. In particular, the present invention allows the check valve to be easily incorporated into a vent pipe that supplies fresh air.

Disclosure of Invention

In order to achieve this object, the invention relates to an oil separator for an internal combustion engine, in particular an oil separator intended to be arranged on a cylinder block of such an internal combustion engine, the oil separator comprising:

a chamber;

an inlet formed in the chamber intended to admit fresh air, in particular fresh air tapped from downstream of the air filter and/or upstream of the turbocharger; and

an outlet formed in the chamber intended to deliver fresh air into the cylinder block, in particular into the lower part of the crankcase,

to vent blow-by gases and/or oil vapors from such cylinder blocks.

The fresh air chamber may be adjacent to the separation chamber of the oil separator.

The oil separator may include a check valve disposed at the inlet to allow flow to exit the chamber only via the outlet.

The separator may comprise an oil return duct passing through the chamber in a sealed manner.

The chamber may be a passageway extending between an inlet and an outlet.

The passage may pass through a separation chamber of the oil separator.

The invention also relates to an internal combustion engine comprising a cylinder block, in particular an internal combustion engine comprising an intake pipe comprising an air filter and/or a turbocharger, the internal combustion engine comprising an oil separator as defined above and an air ventilation pipe extending between an inlet of the chamber and a fresh air tap, in particular a tap formed downstream of the air filter and/or upstream of the turbocharger.

The invention also relates to a vehicle, in particular a motor vehicle, comprising an internal combustion engine as defined above and/or an oil separator as defined above.

Drawings

These objects, features and advantages of the invention will be set forth in detail in the following description of a particular embodiment thereof, given without limitation with reference to the accompanying drawings, in which:

FIG. 1 is a schematic illustration of a vehicle including an internal combustion engine according to one embodiment.

Fig. 2 is a schematic view of an internal combustion engine provided with an oil separator according to one embodiment of the invention.

Fig. 3 is a schematic view of an internal combustion engine provided with an oil separator according to a first variation of the embodiment of the invention.

Fig. 4 is a schematic view of an internal combustion engine provided with an oil separator according to a second variation of the embodiment of the invention.

Fig. 5 is a top view of a cylinder block to which an oil separator according to an embodiment is attached.

Fig. 6 is a cross-sectional view of a cylinder block and oil separator according to an embodiment taken on a plane parallel to the axis of the cylinder through the axis of the fresh air inlet to the oil separator.

Fig. 7 is a side view of a cylinder block and an oil separator according to an embodiment.

Fig. 8 is a cross-sectional view of a cylinder block and oil separator according to an embodiment, taken on a plane perpendicular to the axis of the cylinder and passing through the air chamber of the oil separator.

Fig. 9 is a partial cross-sectional view of a cylinder block and oil separator according to a first variation of the embodiment of the invention, taken on a plane parallel to the axis of the cylinders and passing through the air chamber of the oil separator.

Fig. 10 is another partial cross-sectional view of a cylinder block and oil separator taken on a plane parallel to the axis of the cylinder and passing through the air chamber of the oil separator according to an embodiment of the invention.

Fig. 11 is another cross-sectional view of a cylinder block and oil separator taken on a plane parallel to the axis of the cylinder and through the air chamber of the oil separator according to an embodiment of the invention.

Detailed Description

Fig. 1 schematically illustrates a vehicle 1 (e.g., a motor vehicle). The vehicle 1 includes an internal combustion engine 2. The internal combustion engine 2 is, for example, the only means of traction and/or propulsion of the vehicle 1. Alternatively, the electric devices (e.g. devices comprising electric motors, and electric energy accumulation devices) also contribute to the traction and/or propulsion of the vehicle 1, which is then referred to as a hybrid vehicle.

The internal combustion engine 2 includes a cylinder block 3. The cylinder block 3 includes at least one cylinder. For example, as illustrated in particular in fig. 5, the cylinder block 3 comprises three cylinders 3C. The internal combustion engine 2 further includes an oil separator 10. Preferably, the oil separator 10 is disposed on the cylinder block 3. By "arranged" is meant that the oil separator is fixed to the cylinder block 3 or that the oil separator is incorporated into the cylinder block. According to one embodiment, the oil separator may be part of a cylinder block.

As is illustrated in particular in fig. 2, 3 and 4, the internal combustion engine 2 comprises an intake pipe 5. The inlet line 5 comprises an air filter 7 and/or a turbocharger 8. The engine 2 also includes an air duct 6.

As particularly illustrated in fig. 2, 3, 4 and 6, the cylinder block 3 comprises a crankcase 4. Preferably, the oil layer H remains at the bottom (according to the vertical direction) of the crankcase 4.

The housing of the oil separator 10 includes a separate chamber 20. The chamber 20 is intended to receive fresh air F. Preferably, this fresh air F is tapped downstream of the air filter 7 and/or upstream of the turbocharger 8. Fresh air F arrives in the chamber 20 via the duct 6. For this purpose, an inlet 21 is formed in the chamber 20. The fresh air F thus reaches the chamber 20 via the inlet 21. An outlet 22 is formed in the chamber 20 to open into the cylinder block 3, as shown in fig. 11. The outlet 22 is intended to remove air from the air chamber 20 and to deliver this fresh air F into the cylinder block 3. Fresh air F is preferably delivered into the crankcase 4 to expel blow-by gases and/or oil vapors present within the cylinder block 3. Preferably, the duct 6 extends between the inlet 21 of the chamber 20 and the fresh air tap 9. Advantageously, the tap 9 is thus formed downstream of the air filter 7. The fresh air F tapped off is therefore filtered air and therefore free of dirt and/or dust. The conduit 11 allows the separated oil RH to return by providing communication through the cylinder block between the internal volume of the separator 10 and the volume of the oil sump.

As illustrated in fig. 5, 6, 7, 9, and 10, the housing of the oil separator 10 includes a check valve 30. Advantageously, a check valve 30 is incorporated into the housing of the oil separator 10 to control the closing of the inlet 21. Thus, due to the presence of this check valve, only a flow leaving the chamber 20 via the outlet 22 is possible.

According to a first variant illustrated in fig. 3 and 9, the separator 10 comprises a duct 11 for returning the separated oil RH through the chamber 20. Preferably, the duct 11 passes through the chamber 20 in a sealed manner. For example, the outlet 22 is formed below the duct 11, as shown in fig. 3.

According to a second variant, shown in fig. 4, the fresh air chamber 20 is a passage. In other words, the internal volume of the chamber is equal or substantially equal to the internal volume of the passageway 25. The passage 25 thus extends, for example, linearly between the inlet 21 and the outlet 22. Preferably, the passage 25 is arranged, for example, horizontally or substantially horizontally, in the lower part of the separator. Further preferably, a passage 25 is arranged below the junction 12 between the pipe 11 for returning the separated oil RH and the separator 10. Thus, the passage 25 may be in the separation chamber 13 of the separator.

In summary, the purpose of the ventilation duct 6 is to convey the (preferably filtered) fresh air F into the cylinder block, in particular into the lower part of the crankcase 4. Blowby gases and oil vapors produced by combustion of the air-fuel mixture are thus expelled and pass through the oil separator 10 via the inlet conduit. Thus, a separator or separation unit arranged on the outside of the engine, more particularly on the outside of the cylinder block 3, receives blowby gases from the cylinder block, in particular from the crankcase.

As illustrated in fig. 2, 3 and 4, the engine 2 preferably comprises a first conduit 14 connecting, for example, the internal volume of the separator from the top 15 thereof to, for example, an air manifold 40. Preferably, the engine 2 further comprises a second conduit 16 connecting, for example, the internal volume of the separator from a side 17 thereof to, for example, the intake pipe 5, for example upstream of the turbocharger 8. In this way, blowby gas BB trapped in the oil separator due to the ventilation of the cylinder block with fresh air F may escape via the first conduit 14 and/or via the second conduit 16. Blow-by gases BB are thus made to reach the intake pipe 5, which are thus injected as intake air from the turbocharger 8 and/or directly from the air filter 7, for example at the cylinder head 18. Thus, one advantage of placing fresh air adjacent to the separation is to allow heat transfer between the blowby and fresh air, which promotes separation of the oil vapor. In particular, the gas from which the oil is removed benefits from cooling.

In other words, the check valve of the cylinder block vent circuit is incorporated into an oil separator, creating an air chamber within the oil separator. The air chamber communicates with the cylinder block, particularly at the crankcase, via a fluid-tight tap, e.g. using a gasket, at the interface between the outlet of the air chamber and the cylinder block.

It should be noted that the pipe 6 is able to perform a second function, namely to keep the interior of the cylinder block at a reduced pressure at all times by means of a non-return valve. In particular, as mentioned previously, the check valve prevents blowby gas from flowing back to the air intake pipe via the pipe 6, particularly in the event of a pressure rise. It should be remembered that fresh air F is collected downstream of the air filter 7 and upstream of the compressor 8 to reach the oil separator 10. As mentioned previously, in the embodiment and in the first and second variants, the volume of the separator is in communication with the cylinder block 3.

Therefore, the check valve is placed on the path of the pipe 6, in the vicinity of the cylinder block 3, but is not fixed to the cylinder block 3. This simplifies the cylinder block, since it does not require special fixtures for the non-return valve, such as screws and/or threaded bores and/or bores for receiving the non-return valve. Thus, the cost of the blowby gas venting and separation function is reduced in view of the elimination of such fasteners. Furthermore, the path of the tube 6 is simplified, since the number of components constituting the path, in particular with small curvature and compact radius, is reduced. It should be noted that only the oil separator is modified to simplify the vent pipe. Finally, the tube 6 is more accessible for intervention, since the assembly and disassembly of the tube is easier, both at the factory where the engine is assembled and in after-market service.

In a first variant, illustrated in particular in fig. 3 and 9, the duct 11 passes through the air chamber 20 and therefore the circuit for the blowby gas BB expelled as a result of the ventilation of the fresh air F passes through this air chamber. This allows the oil to be cooled during passage through the chamber 20 filled with fresh air. Since the temperature of the fresh air F is theoretically lower than the temperature of the oil.

It should be noted that the solution according to the invention thus achieves the desired aim of simplifying the duct of the cylinder block discharging blowby gases and of easily incorporating the check valve, and offers the following advantages:

low cost, preferably only modifying the separator;

it can be applied to any internal combustion engine that employs an oil separator.

Claims

1. An oil separator (10) for an internal combustion engine (2), in particular an oil separator (10) intended to be arranged on a cylinder block (3) of such an internal combustion engine (2), characterized in that the oil separator (10) comprises:

a chamber (20);

an inlet (21) formed in the chamber (20) intended to admit fresh air (F), in particular fresh air (F) tapped from downstream of the air filter (7) and/or upstream of the turbocharger (8); and

an outlet (22) formed in the chamber (20) intended to deliver fresh air (F) into the cylinder block (3), in particular into a lower portion of the crankcase (4), to evacuate blowby gases and/or oil vapors (BB) from such a cylinder block (3).

2. The oil separator (10) according to the preceding claim, characterized in that the fresh air chamber (20) adjoins a separation chamber of the oil separator (10).

3. The oil separator (10) according to any one of the preceding claims, characterized in that the oil separator (10) comprises a check valve (30) arranged at the inlet (21) to allow flow to leave the chamber (20) only via the outlet (22).

4. The oil separator (10) according to one of the preceding claims, characterized in that the separator (10) comprises an oil return duct 11 which passes through the chamber (20) in a sealed manner.

5. The oil separator (10) of one of the preceding claims, characterized in that the chamber (20) is a passage (25) extending between the inlet (21) and the outlet (22).

6. The oil separator (10) of the preceding claim, characterized in that the passage (25) passes through a separation chamber of the oil separator.

7. An internal combustion engine (2) comprising a cylinder block (3), in particular an internal combustion engine (2) comprising an intake pipe (5) comprising an air filter (7) and/or a turbocharger (8), characterized in that it comprises an oil separator (10) as claimed in one of the preceding claims and an air ventilation pipe (6) extending between an inlet (21) of the chamber (20) and a fresh air tap (9), in particular a tap (9) formed downstream of the air filter (7) and/or upstream of the turbocharger (8).

8. A vehicle (1), in particular a motor vehicle, characterized in that it comprises an internal combustion engine (2) according to the preceding claim and/or an oil separator (10) according to one of claims 1 to 6.