JPH10220563A - Mist separator for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To bleed the gear case of an internal combustion engine of blowby gas and return the air obtained through the removal of lubricating oil from the gas to the charging system of the engine by way of a breather with the use of a mist separator, and prevent the mixture of lubricating oil in the oil pan of the engine into new charge. SOLUTION: A mist separator MS for an internal combustion engine is disposed in the housing of a blowby-gas bleeder passage interposed between a gear case 1 and a breather 3. The separator MS comprises a rotary disk 7 fitted on a geared shaft 6 for driving a fuel injection pump, the disk 7 being selectively provided with blades, or comprises an initially corrugated rotary disk. Between the separator MS and an oil pan OP is interposed an oil return pipe 5, which is provided midway with a checking stop valve adapted to close upon boost pressure as pilot pressure or with a checking stop valve having the function of oiling a supercharger during the start-up of an internal combustion engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear case for extracting blow-by gas from a gear case in an internal combustion engine and returning air after separating lubricating oil to an air supply system or discharging the air to the atmosphere. The present invention relates to a mist separator disposed in a blow-by gas extraction passage on the front side of a breather to be mounted.

[0002]

2. Description of the Related Art In a conventional internal combustion engine, a breather is provided on a valve arm chamber cover, and blow-by gas collected from the breather is passed through a mist separator to remove lubricating oil and then returned to an air supply system or to the atmosphere. Emission configurations are known.

Further, when a breather is provided in the valve arm chamber cover, since the position of the breather is increased and a separate mist separator is also required, blow-by gas may be extracted from the gear case and introduced into the breather. For example, Japanese Utility Model Laid-Open No. 7-30309. But,
In this case, since the position of the breather is also low, it is difficult to install a mist separator that exhibits an effective separating action due to the difference in elevation, and there is also a problem in installation space. Therefore, it has been considered to dispose a mist separator in a passage for extracting blow-by gas in the gear case, and to introduce blow-by gas that has passed through the mist separator into a breather.
No. 0 disclosure.

[0004]

Problems to be Solved by the Invention
In the mist separator in front of the breather in Japanese Patent Publication No. 10, the fuel injection pump drive gear shaft is inserted into a blow-by gas extraction passage, and a spiral is formed in this insertion portion. However, in this case, since there is no effective separation action unless the length of the spiral portion is increased, the passage for extracting the blow-by gas must protrude longer than the gear case and lacks compactness. If the centrifugal force of the fuel injection pump shaft can be used effectively, the separation effect will be greater,
It seems that a compact mist separator can be constructed.

The lubricating oil separated by the mist separator is returned to the oil pan. From the mist separator, an oil return pipe to the oil pan and a pipe for supplying air to the air supply system via a breather are provided. When the engine is running, the lubricating oil in the oil pan is
It is sucked into this supply air return pipe and flows into the air supply system. If air mixed with lubricating oil is mixed into the air supply, there is a possibility that engine runaway may occur due to the combustion of the mixed lubricating oil.

[0006]

The present invention uses the following means in order to solve the above problems. First, a mist separator having a rotating disk driven by a fuel injection pump drive gear shaft was provided in a breather attached to a gear case of an internal combustion engine. Further, wings or wavy portions were formed on the rotating disk of the mist separator.

Further, a mist separator is provided in a breather of a supercharged internal combustion engine, and a valve is opened at the time of pilot pressurization by using a supercharged pressure as a pilot pressure in an oil passage for returning separated oil to an oil pan. An on-off valve that is sometimes closed is provided. Further, a lubrication path is provided from the on-off valve to the supercharger,
The valve is opened when the engine starts, and the lubricating oil separated by the mist separator is supplied.

[0008]

Embodiments of the present invention will be described with reference to the accompanying drawings. 1 is an assembled perspective view of a blow-by gas extraction passage and a breather with respect to a gear case 1, FIG. 2 is a side sectional view showing a mist separator MS having a rotating disk 7 in the blow-by gas extraction passage, and FIG. FIG. 4 is a side sectional view showing a mist separator MS having a disk 7, and FIG.
Side sectional view showing a mist separator MS comprising
FIG. 5 is a front view of the waveform rotating disk 7 ', and FIG.
7 is a side cross-sectional view of the check valve V interposed in the oil return path from the mist separator MS to the oil pan OP when the pilot is pressurized, and FIG. FIG. 9 is a system diagram of a conventional air supply reduction system,
FIG. 10 is a system diagram of the air supply and reduction system provided with a check valve V in the oil return path, and FIG. 11 is a side cross-sectional view of the check valve V ′ having an oil supply mechanism to the supercharger. FIG. 12 is a diagram showing a state when the engine is stopped, FIG. 12 is a diagram showing a state when the engine is started, and FIG. 3 is a diagram showing a state when the engine is running.

First, the assembling structure of the blow-by gas extraction passage and the breather with respect to the gear case 1 will be described with reference to FIG. The blow-by gas extraction passage housing 2 is attached to the blow-by gas extraction hole 1a of the gear case 1. A mist separator MS described later is provided inside the blow-by gas extraction passage housing 2. An air duct 2a protrudes upward from the blow-by gas extraction passage housing 2. A breather 3 is mounted on the air duct 2a, and an air reduction pipe 4 extends from the breather 3. That is, the air from which the lubricating oil has been removed by the mist separator MS in the blow-by gas extraction passage housing 2 is introduced into the breather 3 and the air reduction pipe 4 from the air duct 2a. The other end of the air return pipe 4 is connected to a part of an air supply system to reduce air to the air supply system or to discharge air to the atmosphere.

On the other hand, an oil return port 2b is opened below the blow-by gas extraction passage housing 2, and an oil return pipe 5 extends from the oil return port 2a. Connect to the engine oil pan OP. That is, the lubricating oil separated by the mist separator MS in the blow-by gas extraction passage housing 2 is returned to the oil pan OP via the oil return port 2a and the oil return pipe 5.

Next, the mist separator M according to the present invention
S will be described. Mist separator MS of the present invention
To form the fuel pump drive gear shaft 6 shown in FIG. 2 and other drawings, the fuel pump drive gear shaft 6 projects outward from the blow-by gas extraction hole 1 a of the gear case 1 and is inserted into the blow-by gas extraction passage housing 2. Then, in the blow-by gas extraction passage housing 2, as shown in FIG. During engine operation, the fuel pump drive gear shaft 6 rotates with the rotation of the crankshaft, and accordingly, the rotating disk 7 rotates within the blow-by gas extraction passage housing 2.

Blow-by gas G is introduced from inside the gear case 1 into the blow-by gas extraction passage housing 2, passes by the fuel pump drive gear shaft 6, and comes into contact with the side surface of the rotating rotating disk 7 facing the gear case. And then travels centrifugally on the opposite side of the rotating disk 7. In this process, the lubricating oil L in the blow-by gas G adheres to the surface of the rotating disk 7. After the lubricating oil L is thus separated, the air A flows out of the air duct 2a to the breather 3 as described above, and the lubricating oil L attached to the rotating disc 7 is
It is blown off along with the rotation, falls along the inner wall of the blow-by gas extraction passage housing 2 and returns to the oil return port 2b.
The oil is further discharged to the oil return pipe 5.

As described above, the mist separator MS of the present invention allows the lubricating oil to adhere to the rotating disk 7 and has a small width, and the blow-by gas extraction passage housing 2 containing the same is also large outward. Because they do not need to be projected, they are compact. On the other hand, since the area of interference between the blow-by gas G and the rotating disk 7 is large, a large amount of oil can be obtained. In other words, compact,
It is a mist separator with good separation efficiency. Further, due to the centrifugal force caused by the rotation, the attached lubricating oil L easily falls and is discharged to the oil return pipe 5, the discharge efficiency of the lubricating oil L is good, and the lubricating oil L Adhesion performance can be maintained.

Further, in the embodiment shown in FIG.
Is provided with a wing 7a. The wing 7a rotates together with the rotating disk 7 and causes a large amount of the lubricating oil L to adhere to the surface thereof. That is, the adhesion efficiency of the lubricating oil L increases. Of course, the lubricating oil L attached to the surface of the blade 7a is also quickly blown off by the centrifugal force caused by the rotation. Further, since the blow-by gas G is forcibly introduced from the inside of the gear case 1 into the blow-by gas extraction passage housing 2 by the rotation of the blade 7a, the inside of the gear case 1 is blow-by gas extraction passage housing 2.
It becomes slightly negative pressure than inside. Therefore, after being blown off, the lubricating oil L does not enter the gear case 1 through the blow-by gas extraction hole 1a in the process of traveling along the inner wall of the blow-by gas passage housing 2, and the oil return pipe 5 and the oil pan O
It is recovered to P.

FIGS. 4 to 6 show a mist separator MS having a wavy rotating disk 7 'formed in a radial waveform.
Is disclosed. In the process in which the blow-by gas G passes through the blow-by gas extraction passage housing 2, the lubricating oil L in the blow-by gas G adheres well to the radial groove 7'a formed in the wavy shape. With the rotation, the lubricating oil L flows smoothly in the centrifugal direction in the groove 7'a, so that the lubricating oil L is smoothly discharged from the corrugated rotating disk 7 '.

Next, in the supercharged internal combustion engine employing the air supply reduction system for returning the air blown out from the breather 3 to the air supply system after passing through the mist separator MS, the check opening and closing of the present invention is carried out in the oil return path. An embodiment in which the valve V is provided will be described with reference to FIGS.

First, the structure of the check valve V according to the present invention will be described with reference to FIGS. A valve chamber 8a is formed in the valve holder 8, one end of the valve chamber 8a is a closed end, and the other end is opened to introduce a part of the supply air A 'supplied from the supercharger T. It communicates with the pressure tube 11. Then, oil passages 8b and 8c are formed so as to be orthogonal to the valve chamber 8a, and the oil passages 8b and 8c are communicated with an intermediate portion of the oil return pipe 5.

An on-off valve 9 is slidably fitted in the valve chamber 8a, and a valve spring 10 is interposed between the on-off valve 9 and the closed end of the valve chamber 8a. Oil seals 9b, 9b are engaged near both ends of the on-off valve 9, and a passage 9a is formed between the oil seals 9b, 9b so as to communicate with the oil passages 8b, 8c.

During the operation of the engine, a part of the supply air A 'is introduced from the supercharging pressure pipe 11, and the supercharging pressure becomes a pilot pressure, and the opening / closing valve 9 is pushed against the valve spring 10; The opening and closing valve 9 closes between the oil passages 8b and 8c. This prevents the lubricating oil in the oil pan from flowing backward from the oil passage 8c to the oil passage 8b and being introduced into the air supply system via the mist separator MS and the breather 3. When the engine is stopped, the supercharging pressure is not applied, the pilot is in a non-pressurized state, and the on-off valve 9 is pushed back by the valve spring 10,
The passage 9a communicates with the oil passages 8b and 8c, and the mist separator MS communicates with the oil pan OP.
Therefore, the lubricating oil L separated by the mist separator MS is collected in the oil pan OP.

FIG. 9 and FIG. 10 compare the air supply and return system in the case where such a check valve V is not provided in the middle of the oil return pipe 5. FIG. 9 shows a conventional air supply / reduction system without a check valve V, in which a blow-by gas G extracted from a gear case 1 is subjected to removal of a lubricating oil L by a mist separator MS to form a breather. 3, the oil is returned to the supercharger T via the air pipe 4, but the oil return pipe 5 is moved from the mist separator MS to the oil pan OP.
The breather 3 is connected to the oil pan O
It is also connected to P, and by the blowing action of the breather 3,
The lubricating oil L in the oil pan OP may be sucked and blown out to the supercharger T. If lubricating oil is mixed during air supply, there is a risk of engine runaway.

As shown in FIG. 10, the check valve V according to the present invention is provided in the middle of the oil return pipe 5 through an air supply pipe (air supply manifold) 12 extending from the supercharger T. A part of the supply air A ′ supplied at the supercharging pressure is taken in as the pilot pressure via the supercharging pipe 11. During engine operation, the boost pressure pipe 1
When the supercharging pressure, that is, the pilot pressure is increased from 1, the check valve V closes and the oil return pipe 5 closes halfway, so that the lubrication between the breather 3 and the oil pan OP is stopped. The flow of the oil L is discontinued. Therefore, mixing of lubricating oil during air supply is avoided.

The check valve V is in a state in which the lubricating oil L is blocked in the passage 9a of the valve 9 during operation of the engine. This lubricating oil L is used effectively, and the supercharger T
If lubrication is performed in a timely manner, the lubrication structure can be simplified. Therefore, as shown in FIGS. 11 to 13, a check valve V 'having such a lubrication structure is provided. This configuration will be described. In the valve holder 8 ', similarly to the valve holder 8, the valve chamber 8' and the oil passages 8'b and 8'c (oil passages 8'b) communicating with the valve chamber 8 '. Is connected to the mist separator MS, and the oil passage 8'c communicates with the oil pan OP.), And an oil passage 8'd communicating between the valve chamber 8 'and an oil hole provided with the supercharger T is formed. Has formed.

The on-off valve provided in the valve chamber 8'a is as follows.
Instead of the on-off valve 9, it is divided into a first on-off valve 13, which operates by the supercharging pressure of the pilot pressure, and a second on-off valve 14, which is connected to a solenoid valve and forcibly operates. The gap between the first on-off valve 13 and the second on-off valve 14 corresponds to the passage 9 a in the on-off valve 9.

More specifically, the air supply manifold 12
A sleeve 15 is slidably fitted in a connecting portion where the extending boost pressure pipe 11 communicates with the valve chamber 8'a. A valve spring 16 is interposed between the first on-off valve 13 and the first on-off valve 13. An oil chamber 13a is formed in the first on-off valve 13 along the axis thereof in the sliding direction, and an oil introduction path 13b for communicating the lubricating oil chamber 13a with the outer surface, and an oil outlet path 13c.

Then, the oil passages 8'b and 8'c are separated by
A second on-off valve 14 fixedly mounted on the solenoid end of a solenoid valve 18 is slidably fitted in the valve chamber 8'a from the side opposite to the pipe side of the supercharging pressure pipe 11, and the first on-off valve 13 A valve spring 17 is interposed between the first and second on-off valves 14.

In the above configuration, first, FIG.
When the engine is stopped, the pilot pressure due to the supercharging pressure is in a non-pressure state. At this time, the solenoid of the solenoid valve 18 and the second on-off valve 14 are in the initial position, and the first on-off valve 13 is moved to the sleeve 1 by the urging force of the valve spring 17.
5 and the valve spring 16 side. Therefore, the space between the first on-off valve 13 and the second on-off valve 14 is opened, and the oil passage 8 ′ is opened.
The b and 8'c are communicated with each other, and the lubricating oil is recovered after separation from the mist separator MS into the oil pan OP. On the other hand, as shown in FIG. 13, when the engine is running, the solenoid valve 18 is also in the initial state, and the second on-off valve 14 is in the initial position. The sleeve 15 is the valve spring 16
, The first on-off valve 13 is also pushed, the valve spring 17 is also contracted, and the first on-off valve 13 and the second on-off valve 1
4 are in close contact with each other, and the oil passages 8'b and 8'c are shut off.

The above is the control of the on-off valve between the oil passages 8'b and 8'c by the pilot pressure of the supercharging pressure in the check valve V '. The control will be described. First, as shown in FIG. 11, when the engine is stopped, the oil introduction passage 13b and the oil outlet passage 13c of the first on-off valve 13 are provided.
Is closed by a valve holder 8 '.
When the solenoid valve 18 is operated from this state,
As shown in FIG. 12, the second on-off valve 14 is pushed by the solenoid,
Further, the second on-off valve 14 pushes the first on-off valve 13, the first on-off valve 13 slides against the valve spring 16, and the oil outlet passage 13c communicates with the lubrication passage 8'd. As a result, the separated lubricating oil L accumulated in the oil chamber 13a is supplied to the supercharger T via the oil outlet path 13c and the oil supply path 8'd.

The operation timing of the solenoid valve 18 is set when the engine is started. When the engine is started, the supercharging pressure has not yet been applied from the supercharging pressure pipe 11 into the valve chamber 8'a, and the sleeve 15 is at the terminal position of the valve chamber 8'a.
The operation of the solenoid valve 18 is effective, and the first on-off valve 13 smoothly enters the state shown in FIG. After that, when the supercharging pressure is introduced from the supercharging pressure pipe 11 by the engine operation, the solenoid valve 18 and the second on-off valve 14 are returned to the initial positions. The first on-off valve 13 is pushed by the supercharging pressure and the second on-off valve 14
As shown in FIG. 13, at this time, only the oil introduction passage 13b communicates with the oil passage 8'b (the oil lead-out oil 13c is closed by the valve holder 8 '), and the mist is formed. The separated lubricating oil L sent from the separator MS is
The oil is introduced into the oil chamber 13a to prepare for the next lubrication.

[0029]

According to the present invention having the above-described configuration, the following effects can be obtained. First, by forming the mist separator according to the first aspect, the rotating disk extends in the radial direction of the fuel pump drive gear shaft, and does not require a large width in the axial direction. Therefore, the blow-by gas passage to be attached to the gear case does not need to be expanded so much in the lateral direction, and the configuration is compact. Further, since the fuel pump drive gear shaft is used as it is and no other drive means is required, the cost is low. Despite such a compact configuration, the contact area between the blow-by gas and the rotating disk can be increased, so that the lubricating oil adheres well and the lubricating oil is rotated by the centrifugal force generated by the rotation. Released from the plate and collected in an oil pan. That is, the lubricating oil recovery efficiency is good, and the rotating disk can be used for a long time.

Further, in the mist separator having the structure as described in the first aspect, by forming the wings and the corrugated portion on the rotating disk, the adhesion of the lubricating oil in the blow-by gas is further enhanced. At the same time, the release of the lubricating oil from the rotating disk due to the centrifugal force accompanying the rotation increases smoothness. Therefore, the efficiency of collection in the oil pan is further improved.
In addition, the rotation of the blades also has the effect of making the inside of the gear case a more negative pressure than the inside of the blow-by gas passage, and also prevents the backflow of lubricating oil from inside the blow-by gas passage into the gear case.

With this configuration, during engine operation, the pilot pressure is established by the supercharging pressure, the on-off valve is closed, and the oil pan, the mist separator and the breather are closed. Since the communication of the lubricating oil between the oil pans is interrupted, the lubricating oil in the oil pan is prevented from being mixed into the air supply, and adverse effects such as engine runaway are avoided. Further, when the engine is stopped, the supercharging pressure disappears, the pilot is in a non-pressurized state, the on-off valve opens, and the lubricating oil separated by the mist separator is collected in the oil pan.

Further, by providing a lubricating structure to the supercharger according to the fourth aspect of the present invention, the on-off valve having the structure according to the third aspect can sufficiently lubricate bearings and the like of the supercharger even when the engine is started. As a result, seizure can be prevented, and lubrication oil separated by a mist separator is used for lubrication. Therefore, there is no waste, low cost, and a simple lubrication structure.

[Brief description of the drawings]

FIG. 1 is an assembled perspective view of a blow-by gas extraction passage and a breather with respect to a gear case 1. FIG.

FIG. 2 is a side sectional view showing a mist separator MS having a rotating disk 7 in a blow-by gas extraction passage.

FIG. 3 is a side sectional view showing a mist separator MS provided with the winged rotating disk 7;

FIG. 4 is a side sectional view showing a mist separator MS provided with a corrugated rotating disk 7 ′.

FIG. 5 is a front view of a waveform rotating disk 7 '.

FIG. 6 is a sectional view taken along line XX in FIG. 5;

FIG. 7 is a side cross-sectional view of the check on-off valve V interposed in the oil return path from the mist separator MS to the oil pan OP when the pilot is pressurized.

FIG. 8 is a side sectional view when the pilot is not pressurized.

FIG. 9 is a diagram of a conventional air supply and return system.

FIG. 10 is a system diagram of an air supply and return system in which a check valve V is provided in an oil return path.

FIG. 11 is a side cross-sectional view of a check on-off valve V ′ having an oil supply mechanism to a supercharger, showing a state when an engine is stopped.

FIG. 12 is a diagram showing a state when the engine is started.

FIG. 13 is a view showing a state during engine operation.

[Explanation of symbols]

 MS Mist separator OP Oil pan T Supercharger V / V 'Non-return valve 1 Gear case 1a Blow-by gas extraction hole 2 Blow-by gas extraction passage housing 2a Air duct 2b Oil return port 3 Breather 4 Air pipe 5 Oil return pipe 6 Fuel injection pump drive gear shaft 7 Rotating disk 7a Blade 7 'Wave-shaped rotating disk 8.8' Valve holder 8a / 8'a Valve chamber 8b / 8'b Oil passage 8c / 8'c Oil passage 8'd Oil passage Reference Signs List 9 opening / closing valve 9a passage 9b oil seal 10 supercharging pressure pipe 11 valve spring 12 air supply pipe (air supply manifold) 13 first opening / closing valve 13a oil chamber 13b oil introduction path 13c oil outlet path 14 second opening / closing valve 15 sleeve 16 valve spring 17 Valve spring 18 Solenoid valve

Claims (4)

[Claims] 1. A mist separator having a rotating disk driven by a fuel injection pump drive gear shaft is provided in a blow-by gas extraction passage provided between a gear case and a breather of an internal combustion engine. Mist separator for an internal combustion engine. 2. The mist separator for an internal combustion engine according to claim 1, wherein a wing or a wavy portion is formed on said rotating disk. 3. A mist separator is provided in a blow-by gas extraction passage interposed between a gear case and a breather of a supercharged internal combustion engine, and a supercharging pressure is supplied to an oil passage for returning separated oil to an oil pan. A mist separator for an internal combustion engine, comprising an on-off valve that opens when a pilot pressure is applied as a pilot pressure and closes when the pilot pressure is not applied. 4. The mist separator for an internal combustion engine according to claim 3, wherein a lubricating path is provided from the on-off valve to the supercharger, the valve is opened when the engine is started, and lubricating oil separated by the mist separator is supplied. A mist separator for an internal combustion engine having a structure.