JP3365121B2 - Blow-by gas recirculation system for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow-by gas recirculation system for an internal combustion engine. [0002] The applicant has previously proposed an apparatus for treating blow-by gas generated due to a gap between a cylinder and a piston of an internal combustion engine. As shown in FIGS. 5 and 6, this device partitions the inside of a cover 2 of a cylinder head 1 into a rocker chamber 6, an expansion chamber 7 and an intake chamber 8 by partitions 3, 4, 5, and a crankcase by a blow-by gas passage 9. The blow-by gas in 10 is introduced into the expansion chamber 7 to separate gas and liquid, and the gas is returned to the intake chamber 8 and the intake port 12 through the orifice 11. With this device, oil can be separated from the blow-by gas and sucked into the cylinder 13. In the above proposal, the blow-by gas passage 9 extending from the crankcase 10 to the cylinder head 1 has only one blow-back gas passage at the rear end of the engine. The blow-by gas passage 9 also serves as a passage for returning the oil, and there is a problem that the oil is blown up again by the blow-by gas and the gas-liquid separation action is impaired. Accordingly, the present invention has been devised in order to provide a blow-by bus recirculation device for an internal combustion engine capable of more accurately performing gas-liquid separation of blow-by gas returned to an intake system. According to the present invention, a cover for covering the upper part of a cylinder head is provided with a partition wall for partitioning the interior into a rocker chamber and an intake chamber, and an orifice is formed in the partition wall to form the orifice. an apparatus for circulate the blow-by gas that has flowed into the rocker chamber to the intake system, to the rocker chamber, that
A bag that separates the inside between the orifice side and the cylinder head side
A full plate is provided, and the
An opening is formed at an appropriate distance from the fiss, and the opening is formed.
To guide the blow-by gas to separate the oil in the gas.
Separating means, and the separating means extends below the opening.
Covers and separates gas flow path and receives separated oil
The partition and the oil pierced by the partition and collected on the upper surface of the partition are syringed.
The oil hole to be dropped on the dahead side and the upper and lower
A flange wall formed at right angles to the
And a throttle formed between the full plate and
The lower end of the flange wall is dropped from the oil hole to the cylinder head side.
When the oil level of the spilled oil is inclined, the oil gets over the above bulkhead
In order to prevent the
It has been issued . With the above arrangement, the baffle plate blocks the blow-by gas flowing into the rocker chamber from the orifice. The separating means separates the blow-by gas flowing along the baffle plate in the process of passing the gas through the opening.
The blow-by gas from which the oil has been separated enters the intake chamber through the orifice and is returned to the cylinder. In addition , the partition guides the blow-by gas into the bent gas flow path, and receives the oil separated in the process. The oil hole drilled in the bulkhead is
Drain the oil that has accumulated in the cylinder head. Extension of bulkhead
Between the upper end of the collar wall formed at the end and the baffle plate
The formed throttle part promotes gas-liquid separation by restricting the flow of the blow-by gas entering between the partition and the opening. In addition, the lower end of the flange wall projects appropriately below the lower surface of the partition wall.
Is dropped from the above oil hole to the cylinder head side.
When the oil level of the spilled oil is inclined, the oil gets over the above bulkhead
To prevent that. An embodiment of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 4 show an embodiment of a blow-by gas recirculation system for an internal combustion engine according to the present invention. In this device, a partition wall 25 extending in the engine longitudinal direction and partitioning the interior into a rocker chamber 23 and an intake chamber 24 is provided on a cover body 22 that covers the upper side of the cylinder head 21, and an orifice 26 is provided on the partition wall 25. Is formed, and the blow-by gas flowing into the rocker chamber 23 is recirculated to the intake system. And rocker room 23
Is provided with a baffle plate 27 separating the orifice 26 side and the cylinder head 21 side. An opening 28 formed in the baffle plate 27 has a baffle plate 2 serving as separating means.
9 are provided. The cover body 22 is divided into two parts by a rocker bracket 32 for supporting the shaft 31 of the rocker arm 30 and a head cover 33 above the rocker bracket 32 with a slanted dividing surface 34 and joined by bolts (not shown). . The rocker chamber 23 of the rocker bracket 32 is
Is inserted into an insertion hole 36 formed in the cylinder head 21 so that the push rod 35 can be inserted. The orifice 26 is formed on the partition wall 25 on the side of the head cover 33 at a position near one end (front end) in the longitudinal direction, and is provided near the upper wall surface 37 of the head cover 33. The hole axis direction of the orifice 26 is slightly upwardly inclined with respect to the intake chamber 24. The intake chamber 24 is provided for the cylinder head 21.
Are connected to the intake ports 38 of the respective cylinders formed in the cylinder. The baffle plate 27 is made of a substantially rectangular thin plate extending in the front-rear direction. One side 53 in the width direction is fixed by bolts 39 at a mounting portion 52 formed near the side wall of the head cover 33, and the other side 54 is partitioned. It is similarly fixed to the head cover 33 at the position of the wall 25. The baffle plate 27 is inclined along the dividing surface 34 in the width direction, and the center 40 in the width direction is appropriately bent so as not to interfere with the rocker arm 30 that swings. The other end (rear end) 41 of the baffle plate 27 in the longitudinal direction is separated from the side wall 42 of the head cover 33 by a predetermined distance to define the opening 28. That is, the opening 28 is formed at the opposite end far from the position of the orifice 26. The partition wall 29 is formed integrally with the step 43 of the rear end wall 46 of the rocker bracket 32, and extends appropriately below the opening 28 below its width. That is, a bent gas flow path 56 is defined by hanging the opening 28 from the gap with the baffle plate 27. The height of the partition wall 29 is formed so that oil accumulated on the upper surface of the cylinder head 21 does not reach even when the engine (vehicle) is inclined. A partition 29 is provided at the extension end of the partition 29.
The upper end 45 is close to the baffle plate 27 with a predetermined gap. That is, the flange wall 44 forms a throttle portion 45 that narrows the flow path of the blow-by gas from the rocker chamber 23. A flange wall 44 and a rear end wall 46 opposed thereto define an oil sump portion 48 having an upper surface 47 of the partition wall 29 as a receiving surface. An oil hole 49 is formed. The lower end 5 of the flange wall 44
0 is appropriately protruded from the lower surface of the partition wall 29. The flange wall 44 is connected to the partition wall 25 as shown in FIG. 2 and extends to a side wall 55 of the rocker bracket 32 on the side of the intake chamber 24. The intake chamber 24 is separated. Next, the operation of this embodiment will be described. The blow-by gas in the crankcase enters the rocker chamber 23 through the insertion hole 36 of the push rod 35 formed in the cylinder head 21. The insertion hole 36
Alternatively, a blow-by gas passage may be formed. The gas that has entered the locker chamber 23 is prevented from flowing above the head cover 33 by the baffle plate 27 and heads toward the opening 28 along the lower surface of the plate. In front of the opening 28, the flow path is narrowed by passing through the narrowed portion 45 of the partition wall 29 (arrow a in FIG. 1) and expanded by the volume of the oil reservoir 48 (arrow b). The oil mist in the gas is separated. Further, in the gas flow path 56 of the partition wall 29, the gas is sucked into the orifice 26 from the opening 28 and bent in reverse (arrow c), and passes a long distance along the upper surface of the baffle plate 27 to the orifice 26 (arrow d). This further promotes gas-liquid separation. The gas passing through the orifice 26 enters the intake chamber 24 (arrows e and f in FIG. 4), merges with fresh air, and is returned to the cylinder via the intake port 38 (arrow g). The oil separated at the opening 28 accumulates on the upper surface 47 of the partition wall 49 and falls from the oil hole 49 onto the cylinder head 21. The oil accumulated on the cylinder head 21 is
Although the oil is discharged through the rod insertion hole 36 and the like, even if the amount of oil increases, the oil does not reach the opening 28 because it is blocked by the partition wall 29. In addition, the engine (body) tilts greatly and the oil level 5
Even if 1 is inclined (for example, the inclination angle α = 35 degrees), or if oil jumps due to a rapid inclination change, the protruding portion of the lower end 50 of the flange wall 44 prevents this, and is prevented from passing over the partition wall 29. You. As described above, the baffle plate 2 for preventing the blow-by gas from being directly sucked into the orifice 26 is provided.
7 is provided, and a partition 29 covering the lower part of the opening 28 is provided, so that the oil contained in the gas can be well separated in the process of flowing to the orifice 26 through the opening 28. The separated oil is stored in the oil sump 48 of the partition wall 29 and is isolated from the position of the gas flow path 56 or the orifice 26. Absent. That is, the gas-liquid separation action is not hindered, and deterioration of oil consumption can be prevented. In this embodiment, since the diaphragm 45 is provided in the partition wall 29, the gas flow path 56 in the opening 28 is formed.
Is formed in a labyrinth path, the opening 28 and the orifice 26 are largely separated from each other, and gas-liquid separation can be performed more sufficiently. Therefore,
There is no need to make the head cover 33 high in order to increase the breather capacity. Further, the partition wall 29 is attached to the rocker bracket 32.
Since it is integrally molded with the rear end face 46, the number of parts can be reduced, and the head cover 33 and the rocker bracket 32 can be easily manufactured by die-casting, each of which is excellent in mass productivity. In this embodiment, the opening 28 of the baffle plate 27 is located at the rear end of the engine and the orifice 2
Although 6 is provided on the front end side of the engine, it may be provided at any position as long as the positions are not excessively close to each other. Further, the shape and size of the baffle plate 27 are not limited to the illustrated example, and should be formed in accordance with the shape of the rocker chamber 23 and the like. In summary, according to the present invention, the gas-liquid separation of the blow-by gas returned to the intake system can be performed more accurately, and the separated oil is blown up by the blow-by gas.
Can be prevented from being mixed into the intake air.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view showing one embodiment of a blow-by gas recirculation device for an internal combustion engine according to the present invention. FIG. 2 is a plan sectional view showing the whole of FIG. 1; FIG. 3 is a plan view showing the baffle plate of FIG. 1; FIG. 4 is a sectional view taken along line AA of FIG. 2; FIG. 5 is a side sectional view showing a conventional blow-by gas recirculation device for an internal combustion engine. FIG. 6 is a sectional view taken along line BB of FIG. 5; DESCRIPTION OF SYMBOLS 21 Cylinder head 22 Cover body 23 Rocker chamber 24 Intake chamber 25 Partition wall 26 Orifice 27 Baffle plate 28 Opening 29 Partition (separating means) 32 Rocker bracket 33 Head cover 45 Restrictor (separating means) 56 Gas flow path

Claims (1)

(57) [Claims 1] A cover body covering an upper part of a cylinder head is provided with a partition wall for partitioning the inside thereof into a rocker chamber and an intake chamber,
The said partition Setsukabe to form an orifice An apparatus for circulated to an intake system of the blow-by gas flowing to the rocker chamber, in the rocker chamber, an orifice side and Siri its internal
Baffle plate separated from the
Place on the raffle plate as appropriate away from the orifice
The blow-by gas is formed in the opening.
A separating means for separating the oil in the gas by conducting the separation;
The means defines a gas flow path covering the lower part of the opening.
And a partition for receiving oil separated therefrom,
Oil hole that drops oil accumulated on the top of the wall to the cylinder head side
And a flange formed at right angles to the extending end of the partition wall in the vertical direction.
A wall is formed between the upper end of the collar wall and the baffle plate.
And a lower end of the flange wall is provided with the oil hole.
When the oil level of the oil dropped from
To prevent the oil from getting over the bulkhead,
A blow-by gas recirculation device for an internal combustion engine, wherein the blow-by gas recirculation device is appropriately protruded below a lower surface of a partition wall .