JP2001065327A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine provided with a device designed so as to prevent storage of oil, to be sufficiently automated and operated with efficiency and reliability and to purify blowby gas in a crankcase. SOLUTION: This internal combustion engine has a drain valve 33 provided between a chamber 28 and the inside of the crankcase, passes oil stored within the chamber 28 through the crankcase and prevents back flow of unpurified gas in an opposite direction. The valve 33 has an opening 34 passing oil from the chamber 28 through the crankcase and a sealing member 38 in fluid-tight cooperation with the opening 34 under a pressure operation of gas within the crankcase. The sealing member 38 senses a change in pressure within the crankcase and enables escape of oil through the opening 34 when pressure within the crankcase becomes a prescribed threshold or below.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine provided with a device for purifying blister gas in a crankcase of an engine.

[0002]

2. Description of the Related Art In an engine, a so-called breather gas (blow-by gas), that is, a gas that escapes from a cylinder through a piston ring into a crankcase, is discharged from a crankcase blazer circuit. Is provided. This escape of the breather gas is necessary both to prevent the pressure in the crankcase from increasing and to ensure the change in volume caused by the movement of the piston.

[0003] Such blow-by gases contain finely atomized oil particles as well as particles of carbon-based unburned material of dimensions or orders of a few μm, typically 5 to 8 μm. In some cases, the breather circuit is of the Opoon type. That is, it discharges breather gas into the atmosphere. In this case, the oil and the particles must be separated due to obvious environmental and health concerns (the particles have a carcinogenic effect).

[0004] In other cases, the breather circuit is closed and recirculates breather gas to the engine intake system to completely burn the particles. But,
In this case, there is a problem that oil and particles are removed from these gases. In fact, oils and particles tend to form resinous deposits on parts, especially on compressors and valves for forced-aspiration engines in intercoolers, thus preventing safe operation of said parts. . Furthermore, in vehicles equipped with a catalytic converter, the combustion of engine oil recirculated to the intake system is detrimental to the catalytic converter and the lambda sensor.

[0005] Thus, various types of purifying devices have been proposed, including, for example, impact separators, filter elements or combinations thereof.

In particular, an inlet communicating with the interior of the engine crankcase, an outlet for the purified breather gas, and an inlet and outlet are provided between the inlet and the outlet so as to receive the breather gas containing the oil floating therein. Purifying the crankcase breather gas with a filtered element and a drain valve designed to allow the oil stored in the chamber to flow to the crankcase but prevent backflow of gas in the opposite direction Devices for causing this to occur are known.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved type of drain valve which operates efficiently, reliably and fully automatically to prevent unwanted accumulation of oil. The invention is to develop an internal combustion engine equipped with a device for purifying the blow-by gas of the crankcase, which is designed to

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to receive a blow-by gas containing oil and particles in a suspended state.
An inlet communicating with the inside of the crankcase of the internal combustion engine, an outlet for purified blow-by gas, a filter provided between the inlet and the outlet, and a chamber for collecting oil separated by the filter And a drain valve provided between the chamber and the inside of the crankcase to allow oil accumulated in the chamber to pass through the crankcase and to prevent backflow of unpurified gas in the opposite direction. The drain valve has at least one opening for passing oil from the chamber to the crankcase, and a seal member that is in fluid-tight cooperation with the opening under the action of gas pressure in the crankcase. This seal member senses a pressure change in the crankcase and detects the pressure in the crankcase below a predetermined threshold. When it is, the oil is achieved by the present invention relates to an internal combustion engine having a device for purifying the blow-by gas, characterized in that it is made possible to escape through the opening.

[0009]

DETAILED DESCRIPTION OF THE INVENTION For a better understanding of the present invention,
Preferred embodiments are described below by way of non-limiting description with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes a cylinder head 2, a plurality of cylinders 3,
1 shows an internal combustion engine having a crankcase 4 and a sump 5 designed to contain lubricating oil. The engine 1 further has a circuit 8 for recirculating so-called breather gas, that is, the gas flowing in the crankcase 4 by passing between the cylinders 3 and the pistons corresponding to these cylinders.

Most of these gases contain carbon-based solid particles (fine particles) and finely sprayed oil particles in a suspended state, which are usually present in unburned matter and oil in combustion. Is formed partially by solid impurities.

A known and not described recirculation circuit is connected to an inlet opening (not shown) communicating with the interior of the crankcase 4 and to an intake system (not shown) of the engine. And a purifying device (FIG. 2) having an outlet connection 9 designed as shown in FIG.

The purification device 7 has an impact separator 10 for trapping coarse particles and a filter 11 for separating residual particles, preferably of the coalescing type, which are arranged in series with one another, It is known to form an integral unit provided with a common case 12. This case 12 is used for the timing gear 1 of the engine 1.
A plurality of screws 13 are attached to the engine 1 so as to be aligned with the openings of the protective case 15 for the flywheel 6 and the flywheel 17. These cases 12
And the protective case 15 substantially constitute a closed cover.

The case 12 includes a plurality of internal baffles 2.
It has a box-shaped inlet section 18 with zeros. These internal baffles define the impact separator 10 and are designed to form a tortuous flow path for the gas. The various duct geometries that define the gas flow path are not described in detail as they do not form part of the present invention.

The case 12 defines an inlet chamber 21 for the substantially rectangular filter 11. The gas leaving the impact separator 10 flows into this chamber. The filter 11 has a filter element 22 in the form of a rectangular cartridge. The filter element comprises a plurality of screws 2 between a peripheral flange 23 of the inlet chamber 21 and a corresponding flange 24 of a removable cover 25 mounted on the case 12.
6 attached.

Advantageously, said filter element 2
Reference numeral 2 denotes a nonwoven fabric cartridge formed of fibers having variable porosity along the thickness direction. The fabric is sandwiched such that the filter face area increases for the same dimension.

[0016] Preferably, the holding capacity of the filter element 19 is such that it can pass particles by itself and has a coalescing function. The cover 25
Defines an outlet chamber 27 for the filter 11 and also integrally forms the outlet connection 9 of the device 7.

Further, the cover 25 is provided with the filter 1
A drain duct 32 (FIGS. 2 and 3) extending from the bottom of one outlet chamber 27 and communicating with the oil collection chamber 28 is integrally formed. The case 12 integrally forms a front wall and a side wall of the oil collection chamber 28. In particular, the oil collection chamber 28 is demarcated below by a pair of side walls 29 that are inclined downwardly and converge on one another to align with the bottom 30 of the chamber. The oil collection chamber 28 is also closed at the rear by a substantially flat wall 31 suitably welded to the side wall.

The oil collecting chamber 28 is connected to the inside of the crankcase 4 via a drain valve 33. The drain valve 33 forms an oil passage from the chamber 28 to the crankcase 4, but is designed to prevent reverse flow of the blow-by gas in the opposite direction. The valve 33 includes a plurality of openings 34 formed in the rear wall 31 so as to be aligned with the bottom 30.
And a closing member 35 attached to the rear wall 31. These openings are, for example, six holes arranged at equal intervals in a circular shape. Further, the closing member 3
5 is designed to close the opening 34 in a liquid-tight manner under the pressure of the blow-by gas.

The closing member 35 is made of an elastic material and has an umbrella shape. That is, the closing member is located at the center of the circular shape defined by the opening 34 at the rear wall 3.
1 has an integral spigot 36 which is forcibly fitted into a hole 37 formed therein and is axially fastened by an integral annular retaining ridge 41 in this hole. The closing member is formed by an annular flange projecting from one end 39 of the spigot 36 in the axial direction, and the rear wall 31 facing the outside of the chamber 28, that is, the inside of the crankcase 4.
Has a flexible sealing member 38 located on the side of The sealing member 38 is provided under the pressure of the blow-by gas at the rear wall 3 at an annular region surrounding the plurality of openings 34.
It has a peripheral tongue 40 designed to cooperate with the one.

The operation modes of the purifying device 7 having the above configuration are as follows. The blow-by gas containing suspended oil and particles flows into the impact separator 10 where coarse oil particles are separated from the flow by inertia and impinge on the baffle 20. The oil thus purified flows into the crankcase 4. The gas flow from which such coarse oil particles have been removed enters the chamber 21 and the filter element 22.

The oil particles passing through the interior of the filter element 22 are now clustered together by coalescence to form droplets of sufficient size to prevent downstream flow. Thus, oil enters the collection chamber 28 from the outlet chamber 27 of the filter 11 through the drain duct 32. Particles that tend to pass through the filter element 22 in the absence of oil are submerged in oil droplets that clump together in the filter element. The gas, from which oil and particles have been removed, flows from the outlet chamber 27 of the filter 11 to the outlet connection 9, from where it is recirculated to the intake system of the engine 1 in a known manner. Oil collected in the chamber 28 tends to flow into the crankcase 4 through the opening 24 in the rear wall 31 of the chamber. Chamber 28
When an overpressure occurs in the crankcase 4,
The seal member 38 closes the opening 34. As a result, the backflow of the contaminated blow-by gas is prevented (FIG. 5).
The dimensions of the seal member 38 are set so that the seal is broken when the pressure value in the crankcase falls below a predetermined threshold value. Under periodic pressure fluctuations in the crankcase when the engine is running, the seal member 38 will allow a small amount of oil to escape into the crankcase even when the engine is running. Making it possible. Then, when the engine is not running, no overpressure is generated in the crankcase 4 and therefore the chamber 28 is completely emptied.

[0022]

The effects that can be achieved by the present invention will be apparent from studying the embodiment of the engine 1, especially the purifier 7. By using a valve 33 with a seal member 35 that senses pressure changes in the crankcase, an undesired accumulation of oil from the chamber 28 can be achieved in an effective, simple and reliable manner, thus eliminating the need for control. It can be drained so that it can be prevented. A valve 33 of the above type is particularly simple and can be manufactured and assembled inexpensively. Also, it is obvious that the engine 1 and the device 7 can be modified and changed without departing from the protection scope defined by the claims. For example, the valve 33 can be changed to a thin plate (lamella) type valve, a diaphragm valve, or a valve provided with a movable closing member as long as the valve 33 can sufficiently sense pressure fluctuation.

[Brief description of the drawings]

FIG. 1 is an internal combustion engine (engine) according to the present invention.
FIG. 4 is a partially cutaway side view of a purification device for the present invention.

FIG. 2 is a front view of a purification device for the engine shown in FIG. 1;

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 shows the first of the valves for the device shown in FIG.
FIG. 4 is an enlarged schematic diagram for explaining the operation position of FIG.

FIG. 5 shows a second valve for the device shown in FIG. 2;
FIG. 4 is an enlarged schematic diagram for explaining the operation position of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 4 ... Crank case, 7 ... Purifier, 9
... outlet connection, 11 ... filter, 12 ... case, 21
... chamber, 22 ... filter element, 25 ... cover, 28 ... collection chamber, 31 ... rear wall, 32 ... drain duct, 33 ... drain valve, 34 ... opening, 35 ... closing member, 36 ... spigot, 37 ... hole, 38 ... seal member, 40 ... peripheral edge tongue.

Claims (10)

[Claims] An internal combustion engine provided with a device (7) for purifying blow-by gas, said device being adapted to receive blow-by gas containing floating oil and particles. An inlet communicating with the inside of the crankcase (4), an outlet (9) for purified blow-by gas, a filter (11) provided between the inlet and the outlet, and the filter (11). A chamber (28) for collecting the separated oil, and the oil stored in the chamber (28) is provided between the chamber (28) and the inside of the crankcase (4). ) And prevents a backflow of unpurified gas in the opposite direction.
3) wherein the drain valve (33) has at least one opening (34) for passing oil from the chamber (28) to the crankcase (4), and a gas in the crankcase (4). A sealing member (38) which cooperates with said opening (34) in a liquid-tight manner under the action of a pressure of And crankcase (4)
An internal combustion engine wherein oil is allowed to escape through said opening when the internal pressure falls below a predetermined threshold. 2. The opening (34) is formed in a wall (31) of the chamber (28), and the valve (33) is a closing member (35) formed of an elastic material.
2. The internal combustion engine according to claim 1, wherein a portion (36) for fastening to the wall (31) and the sealing member (38) is integrally formed. 3. 3. The spigot (3) which is forcibly fitted into a hole (37) of the wall (31).
6), wherein the sealing member (38) is integrally protruded from one end (39) of the spigot (36), and the at least one sealing member (38) is provided on one side of a wall (31) of the chamber (28). A flexible annular flange with a peripheral tongue (40) designed to cooperate fluid-tightly with the area of said wall (31) extending around two openings (34). 3. The internal combustion engine of claim 2, wherein: 4. The valve (33) is connected to the wall (31).
4. The internal combustion engine according to claim 3, wherein the internal combustion engine has a plurality of openings (34) arranged so as to surround the holes (37) formed at equal intervals. 5. The internal combustion engine according to claim 1, further comprising an impact separator (10) disposed upstream of the filter (11). 6. The impact separator (10) and the filter (11) form an integral unit having a common case (12).
Internal combustion engine. 7. A protective case (15) for a timing gear (16) and a flywheel (17), wherein the case (12) of the purifier (7) has an opening in the protective case (15). 7. The internal combustion engine of claim 6, wherein the internal combustion engine is attached to the internal combustion engine in alignment with (14) and substantially forms a closure cover. 8. The internal combustion engine according to claim 1, wherein the filter (11) has a coarse filter element (22). 9. The filter element (22)
9. The internal combustion engine according to claim 8, wherein the internal combustion engine has a holding capacity capable of passing particles contained in the blow-by gas. 10. The case (12) integrally defines an inlet chamber (21) for the filter, and the filter element (22) is detachably mounted on the case (12). A drain duct (32) which is provided between the attached cover (25) and the case (12) and connects the outlet chamber (27) of the filter (11) to the chamber (28), and a filter (11). 10. The internal combustion engine according to claim 8, wherein the internal combustion engine defines an outlet chamber.