JP3342309B2 - Engine blow-by gas recirculation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow-by gas recirculation device for an engine, and more particularly to a blow-by gas provided in an engine for separating oil from blow-by gas leaked from a combustion chamber toward a crank chamber and returning it to an engine intake system. The present invention relates to a reflux device.

[0002]

2. Description of the Related Art Generally, blow-by gas whose unburned gas is about 80% leaks from a combustion chamber of an engine to a crank chamber side. In order to prevent such blow-by gas from being released to the atmosphere, blow-by gas collected in a crank chamber is returned to an intake system of an engine. When performing such recirculation to the intake system, it is desirable to separate the oil component contained in the blow-by gas as much as possible. After the members are lubricated, they are led to the breather chamber and returned from the breather chamber to the engine intake system side.

For example, Japanese Utility Model Publication No. 6-6177 discloses a gas-liquid separation device for an overhead valve engine. In this device, an intake push rod chamber and an exhaust push rod chamber communicate with each other via a locker chamber. Further, a breather up passage which opens an outlet is formed in a side wall of the push rod chamber, and blow-by gas passes through these passages and flows out of the breather chamber to the intake system. Further, a small-diameter oil return passage is formed at the bottom of both push rod chambers, and the crank chamber and both push rod chambers communicate with each other.

[0004] With such a configuration, the oil component of the blow-by gas collides with those wall surfaces and separates during the passage from the crank chamber to each of the above chambers, and flows downward by its own weight. Then, the separated oil is returned to the crank chamber from an oil return passage that opens at the bottom of both push rod chambers.

[0005]

In the above-described gas-liquid separation device, an oil return passage or the like is formed to achieve a configuration in which separated oil is returned to the crank chamber side. There is a danger that oil splashes splashed up in the passage may enter such an oil return passage. Also,
There has been a demand for a gas-liquid separation structure for the blow-by gas guided to the breather chamber to more effectively collide with the wall surface.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and effectively prevents oil from entering the upper part of the crank chamber due to oil jumping up from the crank chamber. It is an object of the present invention to provide a blow-by gas recirculation device for an engine that can more effectively perform gas-liquid separation in the middle of a path of the blow-by gas to an intake system of the engine and can also achieve lubrication of various members during the passage.

[0007]

According to a first aspect of the present invention, there is provided a blow-by gas recirculation apparatus for an engine, comprising: a blow-by gas between a crank chamber and a breather chamber which finally discharges a blow-by gas to an intake system of the engine; A gas-liquid separation chamber, and a through-hole that penetrates the blow-by gas introduction port from the crank chamber to the gas-liquid separation chamber through the outer wall of the gas-liquid separation chamber substantially parallel to the axial direction of the crankshaft. Provided.

Accordingly, the through-hole of the blow-by gas introduction port is oriented in a direction orthogonal to the direction in which the oil splash that is splashed up by the rotation of the crankshaft rises. Is effectively prevented from entering. That is, since the liquid crystal penetrates almost parallel to the axial direction of the crankshaft, it does not directly enter the through hole in the operating direction of the splash that is flipped up by the rotation of the crankshaft.

Further , the gas-liquid separation chamber is vertically divided into a plurality of division chambers by division walls. Then, the blow-by gas introduced from the blow-by gas introduction port is configured to pass through the predetermined plurality of divided chambers and flow into the breather chamber. Therefore, the oil is more effectively separated by effectively preventing the intrusion of oil into the blow-by gas inlet and passing the blow-by gas through the plurality of divided chambers.

[0010]

[0011]

[0012]

[0013]

[0014]

Further, a blow-by gas is introduced upward from a predetermined division chamber, and a blow-by gas ascending passage is provided to guide the blow-by gas to a cylinder head portion above the cylinder block and a locker room further above the cylinder block. And a guide passage for guiding the blow-by gas from the side wall of the divided chamber to the breather chamber.

Accordingly, a blow-by gas flow path is formed from a predetermined divided chamber of the gas-liquid separation chamber to the locker chamber and from the locker chamber to another divided chamber, thereby preventing oil from entering the gas-liquid separation chamber. In addition to the effect, the gas-liquid separation action by the collision in the wall portion of the divided chamber and the locker chamber is more reliably performed.

[0017]

[0018]

[0019]

[0020]

According to a second aspect of the present invention , the blow-by gas recirculation device for an engine is configured such that, after the blow-by gas is introduced into the gas-liquid separation chamber, the blow-by gas is further branched to flow into the governor device. Since the branch passage is guided to the rotating shaft portion of the governor shaft, it is possible to effectively perform a gas-liquid separation effect by colliding with the portion and to add lubricity to the bearing portion.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 schematically shows a part of an overhead valve V-type engine to which an embodiment of the present invention is applied. For simplification of the drawing, hatching indicating a cross section is partially omitted.

As shown, a crankshaft (not shown) is disposed in a crank chamber 12 located below the engine body 10, and a camshaft 14 is provided above the crankshaft. The camshaft 14 and the crankshaft have a parallel rotation axis. A cylinder block 16 is provided above the crank chamber 12, and a cylinder head 18 is further provided above the cylinder block 16. A locker chamber 20 is formed above the cylinder head 18. The figure shows one cylinder portion of the V-type engine, and the cylinder 22 on the opposite side is partially shown in a lower position in the figure.

FIG. 2 is an explanatory view showing a part of the breather chamber 24 in the embodiment of FIG. 1, and as shown, in this embodiment, the breather chamber 24 (shown by a broken line in FIG. 1). Are provided not on the cylinder block 16 but on the upper cylinder head 18.

In the space from the cylinder head 18 to the upper locker chamber, a member (not shown) attached to the intake / exhaust section 70 and a rocker arm (not shown) attached to the support base 72 are accommodated. I have.

The gas-liquid separation chamber, which is a characteristic component of the present invention, has a plurality of vertically divided chambers 26 (four in this embodiment), as clearly shown in FIG. And the crank chamber 1 is composed of divided chambers 26-1, 26-2, 26-3 and 26-4 which are vertically divided into two sections.
2 is located at the upper position. That is, it is formed as a part of the cylinder block 16.

Blow-by gas containing oil leaks into the crank chamber 12 from a combustion chamber (not shown) and enters the crank chamber 12. In the present embodiment, an inlet for introducing the blow-by gas from the crank chamber 12 into the gas-liquid separation chamber 26 is provided at an upper position of the crank chamber 12 and at a corner in the axial direction of the crankshaft. . That is, in FIG. 1, the through hole 30 is formed at a position below the outer wall 28 of the gas-liquid separation chamber in a space 100 extending upward from the crank chamber 12. The portion of the through hole 30 is a boss-shaped inlet formed to be slightly thicker than other portions.

Due to the blow-by gas leaking into the crank chamber 12, the pressure inside the crank chamber 12 becomes positive, and the blow-by gas is supplied to the gas-liquid separation chamber 26 side, in this embodiment, the outermost divided chamber 26- in the axial direction of the crankshaft. 4 flows into the gas-liquid separation chamber 26 from the through-hole 30 provided in the portion 4.

Division room 26-4 and division room 2 adjacent thereto
A through-hole 34 is formed in the divided wall 32 that separates 6-3. The height position of the through-hole 34 is determined by the division room 26-4.
It is formed at a position different from the through-hole 30 which is a blow-by gas introduction port formed on the other wall portion, and in this embodiment, at a higher position.

In the present embodiment, the divided chamber 26
-3 and the division chamber 26-1 located at the corner on the opposite side to the division chamber 26-4 are configured as a storage chamber for the drive unit of the intake and exhaust valves. That is, the divided chamber 26-3 houses the exhaust side tappet 36 and the push rod 38, and the divided chamber 26-1 houses the intake side tappet 40 and the push rod 42.

The divided chambers 26-1, 26-2 and 26
-3 are provided with oil return holes 44 extending in the direction of the crank chamber 12 serving as bottom holes, respectively. The oil return hole 44 is located below the oil return hole 44 in the drawing.
Is provided with a shielding plate 46 for shielding oil from splashing from the crank chamber 12 side.

The blow-by gas that has flowed into the division chamber 26-3 flows upward, and further flows into the cylinder block 16-3.
A blow-by gas ascending passage is formed to guide the blow-by gas to the locker chamber 20 provided thereabove. In this embodiment is constituted by raised walls 48, increase the wall 48 cylinder heads
The partition 18 extends to the inside of the door 18 and bends further down to a position above the dividing wall 50 separating the dividing chamber 26-1 and the dividing chamber 26-2.

The divided chamber 26-partitioned by the rising wall 48
A communication port 52 is provided in the small space 200 in the upper part of the cylinder head 18 above the cylinder head 18 so as to pass to the breather chamber 24 provided outside the cylinder head 18.

As can be understood from FIG. 2, the configuration of the breather chamber 24 is divided into a first chamber 24a and a second chamber 24b, and a reed valve 56 is provided in a passage 54 connecting the two chambers. The flow from the first room 24a to the second room 24b passes through the reed valve 56. The second room 24b is provided with a discharge passage 58 communicating with the intake system.

The recirculation operation of the blow-by gas in the embodiment having the above configuration will be described below. First, the blow-by gas rises from the crank chamber 12, and the gas-liquid separation chamber 26
From the through-hole 30 which is the blow-by gas introduction port
Flow into 6-4. And the through-hole 3 of the division room 26-4
It collides with the wall on the side opposite to 0 and rises, passes through the through-hole 34 of the wall 32 on the adjacent divided chamber side, and flows into the divided chamber 26-3. Here, by colliding with the push rod 38 on the exhaust side, oil can be attached to this portion to lubricate it, and the oil separated by colliding with the wall or the like is separated from the oil return hole 44 provided at the bottom. Fall down from The oil that has dropped falls once onto the upper surface of the shielding plate 46. Since the upper surface of the shielding plate 46 is inclined toward the crank chamber 12, the oil flows down along the inclination.

The function of the shielding plate 46 is that when oil is splashed up in the crank chamber due to rotation of the crankshaft, the splashed-up oil droplets open toward the crank chamber 12 to return oil. This prevents direct intrusion into the hole 44.

The blow-by gas flowing into the division chamber 26-3 flows along the rising wall 48 into the space on the cylinder head 18 side, and further passes through the locker chamber 20 . At this time, by colliding with various drive mechanisms for opening and closing the valve arranged in the locker chamber 20 , the oil component is separated,
These members are lubricated.

The blow-by gas descends from the locker chamber 20 to the division chamber 26 again due to the configuration bent downwardly of the rising wall 48, enters the division chamber 26-1. It enters the division chamber 26-2 from between the lower end. The blow-by gas that has entered the divided chamber 26-1 is supplied to the push rod 4 on the intake side stored therein.
2 and the like, lubricating them, and the oil dripping downward drops through the oil return hole 44 to the outside.

On the other hand, the blow-by gas which has entered the division chamber 26-2 is separated by colliding downward and upward with the inner surface of the rising wall 48, and the oil separated by the collision is removed from the oil return hole 44. Toward the end. On the other hand, the raised blow-by gas is sent to the first chamber 24a of the breather chamber 24 through the communication port 52.

As shown in FIG. 2, the first room 2
The blow-by gas that has flowed into the inside of the lead valve 4a
Is further separated into the oil, flows into the second breather chamber 24b through the passage 54, and is returned to the intake system of the engine through the discharge passage 58.

As described above, according to the present embodiment, the through hole 30 penetrates through the gas-liquid separation chamber wall 28 substantially in parallel with the axial direction of the crankshaft, and the shielding plate 46 is provided. Thus, it is possible to effectively prevent oil splashing from the crank chamber 12 from directly entering the gas-liquid separation chamber. Further, the blow-by gas that has entered the gas-liquid separation chamber 26 is separated from the oil or lubricated by the separated oil by a good collision action with the intake / exhaust valve drive unit and the walls of the divided chambers, and further rises. Wall 4
8 smoothly rises to the upper locker room 2
In addition, the recirculation to the other division chamber 26 is performed favorably, and finally the refrigerant is sent to the breather chamber 24 provided outside the cylinder head 18. Breather room 24
Then, since the gas-liquid separation is further performed in the final stage, the blow-by gas from which oil has been removed is more reliably returned to the intake system.

Another characteristic configuration of the present embodiment is that the blow-by gas flowing from the through hole 30 of the divided chamber 26-4 flows into the adjacent divided chamber 26-3, and also flows to the right in the drawing. That is, it also flows to the governor side passage 60 flowing to the governor device side. Then, the blow-by gas flowing through the governor side passage 60 collides with the rotating bearing portion of the governor shaft 62 and performs an action of lubricating this portion.

FIG. 3 shows the structure of the mounting portion of the governor shaft 62. As shown in FIG.
Is inserted through the cover joining outer edge 64 of the crankcase, and is provided with its tip inserted into the crankcase.

FIG. 4 is an enlarged explanatory view of a rotary bearing portion where the blow-by gas is supplied. As shown, the blow-by gas flowing from the governor side passage 60 passes through the bearing side passage 66 and the governor shaft 62. Collide with The outer diameter of the governor shaft 62 at the collision portion is formed to be slightly smaller than the other portion (the small diameter portion 62).
a), the oil separated at the time of collision therewith adheres and lubrication between the bearing 68 and the governor shaft 62 is favorably performed.

The blow-by gas recirculation device according to the present invention as described above can exhibit its function only by being provided in one of the left and right cylinders of the V-type engine. Further, by providing the breather chamber 24 in the cylinder head portion as in the above embodiment, a wider space can be secured in the V-type engine, and the space above the cylinder can be effectively used.

It should be noted that the present invention is not limited to the configuration shown in the above embodiment, and various modifications can be made within the scope of the invention. For example, the number of divided chambers of the gas-liquid separation chamber 26 is not limited to four as described above, and the number can be reduced or increased. Also, various changes can be made to the divided chamber in which the intake / exhaust valve drive unit is to be stored.

[0047]

As described above, according to the blow-by gas recirculation system for an engine of the present invention, the blow-by gas inlet from the crank chamber to the gas-liquid separation chamber penetrates substantially parallel to the axial direction of the crankshaft. With the opening formed by the mouth, it is possible to effectively prevent oil from directly entering the gas-liquid separation chamber from the crank chamber. Furthermore, when the gas-liquid separation chamber is divided vertically and returned from the division chamber to the division chamber again through the cylinder head and the locker chamber, collision with the wall etc. is effectively planned, and the lubrication action on various members is also improved. Can be achieved.

Thus, it is possible to recirculate the blow-by gas to the engine intake system after removing the oil component of the blow-by gas more appropriately.

[Brief description of the drawings]

FIG. 1 is a partial schematic cross-sectional view of an engine body to which an embodiment according to the present invention is applied.

FIG. 2 is a partially sectional explanatory view of an engine portion in the embodiment of FIG.

FIG. 3 is an explanatory view of a mounting structure of a governor device.

FIG. 4 is an explanatory diagram of a supply state of blow-by gas to a governor shaft portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Engine main body 12 Crank chamber 20 Locker room 24 Breather chamber 26 Gas-liquid separation chamber 26-1, 26-2, 26-3, 26-4 Division chamber 30, 34 Through-hole 32 Division wall 44 Oil return hole 46 Shielding plate 48 Ascending wall 52 Communication port 56 Reed valve

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F01M 13/00 F01M 13/04

Claims (2)

(57) [Claims] 1. A blow-by gas recirculation system for an engine in which blow-by gas leaked from a combustion chamber of a cylinder block above a crank chamber is returned from the crank chamber to an engine intake system via a breather chamber. A gas-liquid separation chamber that separates an oil component and a gas by allowing a blow-by gas to pass between the chamber and a blow-by gas inlet from the crank chamber to the gas-liquid separation chamber; an outer wall of the gas-liquid separation chamber; By forming a through-hole that penetrates almost parallel to the axial direction of the crankshaft ,
And the gas-liquid separation chamber is divided into a plurality of sections vertically divided by a dividing wall.
A blow-by gas introduced from the blow-by gas inlet having a split chamber ;
Passes through the predetermined plurality of divided chambers and passes through the breather.
And the blow-by gas flows upward from the predetermined divided chamber.
And a cylinder provided on an upper part of the cylinder block.
Blow-by gas leading to the locker room above the head
The ascent passage and the blower from the locker room to another divided room
-By-pass gas and blow-by gas
A blow-by gas recirculation device for an engine, further comprising a breather chamber guide passage for flowing into the breather chamber . 2. Combustion of a cylinder block above the crankcase
The blow-by gas leaked from the chamber
Engine returned to the engine intake system via the breather chamber
Blow- by gas recirculation device, the blow-by gas between the crank chamber and the breather chamber.
To separate oil and gas
A gas-liquid separation chamber is provided, and blow-by gas from the crank chamber to the gas-liquid separation chamber is provided.
An inlet is provided on the outer wall of the gas-liquid separation chamber for the crankshaft.
By forming a through hole that penetrates almost parallel to the axial direction
Blow- by gas flowing from the blow-by gas inlet
Is provided with a branch passage for flowing into the governor device side,
The branch passage is guided to the rotating bearing of the governor shaft.
And a blow-by gas recirculation device for an engine.