JPH0640894Y2 - Engine breather device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a breather device in which a blow-by gas introduction hole of an engine is exposed to a blow-by gas guide hole of an engine, and the breather case can be downsized. Provided is one that can maintain high breather performance even when the engine tilts downward.

<Prior Art> The basic structure of an engine breather device to which the present invention is applied is, as shown in FIG. 1 or 7, a blow-by gas guide path 2 and a case communication hole 3 in a crank chamber 1 of an engine E.
The breather case 4 is communicated via the
The blow-by gas introducing cylinder 6 formed on the back surface 18 of the above is exposed to the case communicating hole 3, and the blow-by gas introducing cylinder 6 is communicated with the blow-by gas introducing chamber 5 of the breather case 4.

As a conventional technique of this type, as shown in Japanese Utility Model Publication No. 55-163421 (see FIGS. 7 and 8), a large diameter in which the entire rear surface 18 of the breather case 4 is opened to the main body side of the engine E The blow-by gas introducing cylinder 6 is fitted into the case communicating hole 3 and the breather gas 4 is extended across the breather gas introducing chamber 5, the oil separating chamber 29, and the air purifying chamber 28. And one end surface of the blow-by gas introducing cylinder 6 are connected to the blow-by gas introducing chamber 5 to form the blow-by gas introducing chamber 5 as a mere expansion chamber, and at the upper part of the partition wall 50 of the introducing chamber 5. There is one in which a vent hole 51 is opened and an oil return port 52 is opened under the vent hole 51.

<Problems to be Solved by the Invention> In the above-mentioned conventional technique, the blow-by gas introduction chamber 5 is formed as a simple expansion chamber, so that the partition wall 50 is separated from the inlet 5a as far as possible and the blow-by gas path to the oil separation chamber 29 is lengthened. I am configuring.

As a result, the blow-by gas introduction chamber 5 becomes large and the breather case 4 becomes large as a whole.

In addition, for example, when the engine E is tilted forward and operated for a long time, the oil separated in the breather case 4 is stored in one side of the blow-by gas introduction chamber 5, which is a simple expansion chamber. Since the return port 52 and the ventilation port 51 are closed, the blow-by gas cannot be removed from the outlet 5b of the introduction chamber 5, and there is a great possibility that the oil separation performance in the breather case 4 is significantly deteriorated.

The present invention aims to reduce the size of the breather case and maintain high breather performance even when the engine is tilted.

<Means for Solving the Problems> Means for solving the above problems will be described below with reference to the drawings corresponding to the embodiments.

That is, the first invention is, in the breather device of the engine of the basic structure, the blow-by gas introducing cylinder 6 is extended from the rear surface 18 of the breather case 4 and fitted into the case communication hole 3, and the tip portion 7 of the introducing cylinder 6 is inserted. The blow-by gas is introduced into the internal space 8 of the guide passage 2, and the inlet 5a on the rear surface and the outlet 5b on the upper surface of the blow-by gas introduction chamber 5 are introduced.
The detour plate 30 is inserted in the front-rear direction between the and, and the detour plate 30 is formed in such a shape that the left and right ends 30a are lowered in the middle as seen from the front, and the tip portion 7 of the blow-by gas introduction cylinder 6 is formed. It is characterized in that an oil return port 40 is opened in the lower part of the.

In the second invention, an oil guide groove 17 is formed in the outer peripheral surface of the tip end portion 7 of the blow-by gas introducing cylinder 6 in the circumferential direction,
The oil return port 40 and the oil guide groove 17 are partitioned by an oil shielding rib 41.

<Operation> Since the tip end portion 7 of the introduction tube 6 is made to plunge into the internal space 8 of the blow-by gas guide passage 2, the blow-by gas blown up into the guide passage 2 adheres to the inner wall 10 of the guide passage 2 and falls down. The oil component drops downward along the outer peripheral surface of the introducing cylinder 6 and is less likely to directly enter the introducing cylinder 6, and
The oil guide groove 17 formed on the outer peripheral surface strongly guides the oil downward to prevent oil from entering the introducing cylinder 6 more smoothly.

In addition, by running a bypass plate 30 in the blow-by gas introduction chamber 5 which has a shape in which the left and right ends 30a are lowered at the center when viewed from the front, the blow-by gas is bypassed by the amount by which the bypass plate 30 detours downward. Since the path of the
The oil separation performance can be maintained high even if the height of the breather case 4 is made low, and the entire breather case 4 can be downsized.

Further, even if the oil separated in the breather case 4 is stored in the blow-by gas introduction chamber 5 when the engine E is operated in a forward tilted state for a long period of time, the blow-by gas guide passage 2 from the oil return port 40 is retained. The oil can be stored in the introducing chamber 5 only in the oil level state below the return port 40 by the return action to the blower, so that a space above the inside of the introducing chamber 5 in the inclined state that is not occupied by the oil is secured, and the blow-by The gas can smoothly escape from the upper and side portions of the bypass plate 30 to the introduction chamber outlet 5b.

On the other hand, on the other hand, the oil return rib 40 is provided by the oil shielding rib 41.
And the oil guide groove 17 are separated from each other, the oil guide groove
The oil component guided by 17 is introduced from the oil return port 40 into the introducing cylinder 6
It never invades.

<Effects of the Invention> (1) Since the tip of the introduction tube is pushed into the internal space of the blow-by gas guide passage, the oil that adheres to the inner wall of the guide passage and propagates downwards along the outer peripheral surface of the introduction tube. Therefore, it is difficult to directly enter the introducing cylinder.

(2) By installing a bypass plate that goes up and down in both directions at the inlet of the blow-by gas introduction chamber and the outlet of its upper surface, the upper and lower paths of the blow-by gas are formed longer, and high oil separation performance is maintained. As it is, the height of the introduction chamber can be reduced, so that the entire breather case can be downsized.

(3) When the engine is tilted forward for a long time because a bypass plate of a predetermined shape is run at a predetermined position in the blow-by gas introduction chamber and an oil return port is opened under the tip of the blow-by gas introduction cylinder. However, by ensuring a large space in the blow-by gas introduction chamber that is not occupied by oil,
The blow-by gas can be smoothly discharged to the outlet of the introduction chamber, and the breather performance can be maintained high.

(4) If an oil guide groove is formed on the outer peripheral surface of the introducing cylinder, it is possible to prevent oil from entering the introducing cylinder more smoothly.

Moreover, the oil guided by the oil shielding rib in the oil guide groove does not enter the introducing cylinder through the oil return port.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a left side view of a vertical section of a breather device of a vertical engine, FIG. 2 is a front side view of a part of a breather case, FIG. 3 is a left side view of a breather case, and FIG. FIG. 5 is a view taken in the direction of arrow D, FIG. 5 is a view taken in the direction of arrow F in FIG. 3, and FIG. 6 is a partially cutaway rear view around the oil return port, which is provided in the crank chamber 1 of the vertical engine E. The push-rod fitting hole is formed above the valve camshaft 24 to form the blow-by gas guide path 2.
And the valve rod cam shaft 24 is interlocked with a rocker arm (not shown) of the cylinder head by a push rod arranged in the fitting insertion hole.

Reference numeral 23 is a water jacket.

A case communication hole 3 is formed laterally near the crank chamber 1 of the cylinder block 25 of the engine E so that the tip of the case communication hole 3 communicates with an intermediate part of the blow-by gas guide path 2, and the breather case 4 is fitted into the communication hole 3. Fixed to the cylinder block 25 of the engine E.

That is, the breather case 4 is entirely made of synthetic resin, and has a case body 4a for accommodating the element 26, a back cover 4b for covering the back side of the case body 4a, and a rear half from the lower half of the back cover 4b. And a blow-by gas introducing cylinder 6 having a small diameter.

The case body 4a, as shown in FIG. 2 and FIG.
Partition plate at the bottom of the element chamber (that is, oil separation chamber) 29
The blow-by gas introducing chamber 5 is connected via 33, and the purifying chamber 28 is connected to the upper part thereof via a partition plate 37.

The element 26 is accommodated in the element chamber 29, and the partition plate 33
The outlet 5b of the introducing chamber 5 is opened slightly to the right of, and the element chamber outlet 37a is opened at the left end of the partition plate 37, and the air purifying chamber 29
Project the pipe outlet 27 into the.

A bypass plate 30 having a substantially Ω-shaped cross section is integrally extended in front of the introduction cylinder 6 formed on the back cover 4b, and is projected into the blow-by gas introduction chamber 5 of the case body 4a. A long hole-shaped auxiliary outlet 31 is opened at a position of approximately 30 degrees on the upper left side in the front-rear direction, and the auxiliary outlet 31 is displaced to the left from the outlet 5b of the blow-by gas introducing chamber 5, that is, a partition plate 33. Direct to.

In this case, the blow-by gas leaking from the combustion chamber to the crank chamber 1 is guided to the blow-by gas guide passage 2 → the blow-by gas introducing cylinder 6 → the inlet 5a of the gas introducing chamber → the bypass plate 30 → the outlet 5b of the gas introducing chamber 5. After the oil separation is performed in the element chamber 29, the gas content after the oil separation is released from the purifying chamber 28 to the pipe outlet 27 to the atmosphere (however, it may be returned to the intake system of the engine E). .

Moreover, the blow-by gas that has entered the introduction chamber 5 is a bypass plate.
While bypassing 30 for a long time and adhering the oil component to the bypass plate 30, a part of the oil is blown from the auxiliary outlet 31 to the partition plate 33 and the oil is separated again by the partition plate 33. Since oil is attached from the flat plate portions 30a at both the left and right ends of the blower along the left and right inner walls of the introduction chamber, even if the blow-by gas introduction chamber 5 is formed compactly,
Preliminary oil separation prior to the oil separation in 29 can be favorably performed, and the breather gas breather performance can be improved while making the entire breather case 4 small.

Further, as shown in FIG. 5, a rectangular oil return port 40 is formed in the lower portion of the tip end portion 7 of the blow-by gas introduction cylinder 6, and the double oil guide groove is provided with the oil return port 40 inside. An oil shielding rib (41) is formed between the rib and (17).

In this case, for example, when the engine E tilts downward to the left and tilts upward to the right for a long time (see the tilt line A in FIG. 2), the oil separated from the element chamber 29 is stored in the blow-by gas introduction chamber 5, but the blow-by gas is blow-by. Gas is the right end 30 of the diversion plate 30
Since it can pass through a and the auxiliary outlet 31 to the introduction chamber outlet 5b, a sufficient passage area for blow-by gas can be secured.

On the contrary, when the engine E rises to the left and inclines to the right (see the inclined line B in FIG. 2), oil is also stored in the blow-by gas introduction chamber 5, but the blow-by gas is left at the left end portion of the bypass plate 30. Introduction chamber outlet 5 through 30a and auxiliary outlet 31
You can get out to b.

Further, as shown in FIG. 3, the auxiliary outlet 31 is formed in a long hole shape in the front-rear direction, so that when the engine E inclines forward and downward (see the inclined line C), the bypass plate 31 is The ventilation openings of the left and right ends 30a will be immersed in the oil, but the back side of the auxiliary outlet 31 will continue to be open, so
There is no hindrance to the passage of blow-by gas to the element chamber 29.

Further, in the embodiment, as described in the above <Operation>, even if the engine E inclines in the front downward direction for a long time and the separated oil is stored in the introducing chamber 5, the lower portion of the introducing cylinder tip portion 7 is reduced. The oil return port 40 opened in the lower part lowers the oil surface stored in the introduction chamber 5, and a large space above which is not soaked with oil can be secured, so that the blow-by gas can smoothly escape to the introduction chamber outlet 5b.

On the other hand, since the leading end portion 7 of the introducing cylinder is made to protrude into the internal space 8 of the blow-by gas guide passage 2, the blow-by gas guide passage 2 is formed.
The oil that adheres to the inner wall 10 and propagates down falls down along the outer peripheral surface of the introducing cylinder 6, so that it is difficult to directly enter the introducing cylinder 6.

Further, as shown in FIG. 5 and FIG. 6, since the oil guide groove 17 is formed on the outer peripheral surface of the introduction cylinder 6, the oil is strongly guided downward in the guide groove 17 and the introduction cylinder 6 is introduced. Prevents oil from entering inside more smoothly.

In this case, since the oil return rib 40 separates the oil return port 40 and the oil guide groove 17 from each other, the oil guide groove 17 is formed.
The oil component guided by does not enter the introduction cylinder 6 through the oil return port 40.

However, the detour plate 31 may be formed in a shape that is upward in the middle and downward in the left and right directions when viewed from the rear so that it can be compactly accommodated in the blow-by gas introduction chamber 5 that is formed in a small size. The shape is not limited to the Ω shape, but may be a mountain shape or a gentle wavy shape.

On the other hand, the blow-by gas introducing cylinder 6 is formed in a straight tube shape (that is, the outer diameter of the tip end portion 7 of the introducing cylinder 6 is changed to the base end portion thereof).
(Equal to the outer diameter of 11) is inserted into the case continuous hole 3, the tip portion 7 of the introducing cylinder 6 is projected into the internal space 8 of the blow-by gas guide passage 2, and the outer peripheral surface of the tip portion 7 is inserted. A double oil guide groove 17 is formed in the circumferential direction of 12.

Therefore, in order to attach the breather case 4, it is sufficient to insert the small-diameter straight tubular introduction tube 6 into the case communication hole 3 and fix it with the fixing bolt 20 described below. It is not necessary to form it to a large size, and it is possible to suppress the strength reduction on the main body side and freely select the installation location of the breather case 4.

Further, the fixing bolts 20 and 20 are screwed and supported on the upper portion of the breather case 4 and the central portion of the introducing cylinder 6 both in parallel with the axial direction of the introducing cylinder 6 to support the breather case 4 on the fixing wall of the engine E (that is, , The fixed wall 21 on the inner side of the blow-by gas guide path 2).

At this time, since the case communication hole 3 is sealed by interposing the O-ring 22 on the fitting surface between the introduction cylinder 6 and the case communication hole 3, the fastening force of the fixing bolt 20 is directly applied. The sealing force of the O-ring 22 can be set uniformly in the circumferential direction without being applied to the O-ring 22.

Since the fixing bolt 20 is fixed to the body side of the engine E through the support cylinder 35 to the iron collar 34 ultrasonically press-fitted into the breather case 4 made of synthetic resin, the fastening force of the bolt is not directly applied. It is possible to prevent the breather case 4 made of resin, which is not so strong and is received by the support cylinder 35, from being deformed.

[Brief description of drawings]

1 to 6 show an embodiment of the present invention, in which FIG. 1 is a left side view of a vertical section of a breather device of a vertical engine, and FIG.
The figure shows a partially longitudinal front view of the breather case, FIG. 3 is a longitudinal left side view of the breather case, FIG. 4 is a D arrow view of FIG. 2, FIG. 5 is an F arrow view of FIG. FIG. 7 is a partially cutaway rear view around the oil return port, FIG. 7 is a vertical sectional left side view of a breather case showing a conventional technique, and FIG. 8 is a partial vertical sectional front view of the breather case. 1 ... Crank chamber, 2 ... Blow-by gas guide path, 3 ...
… Case communication hole, 4 …… Breazer case, 5 …… Blow-by gas introduction chamber, 5a …… Blow-by gas introduction chamber inlet,
5b ... Blow-by gas introduction chamber outlet, 6 ... Blow-by gas introduction cylinder, 7 ... Blow-by gas introduction cylinder tip, 8
...... Internal space of blow-by gas guide passage, 17 …… Oil guide groove, 18 …… Breazer case back, 30 …… Detour plate, 30
a …… Both sides of the bypass plate, 40 …… Oil return port, 41 ……
Oil shielding rib, E ... Engine.

Claims (2)

[Scope of utility model registration request] 1. A breather case (4) communicates with a crank chamber (1) of an engine (E) through a blow-by gas guide passage (2) and a case communication hole (3), and a rear surface of the breather case (4) ( The blow-by gas introduction cylinder (6) formed in 18) is made to face the case communication hole (3), and the blow-by gas introduction cylinder (6) is communicated with the blow-by gas introduction chamber (5) of the breather case (4). , In the breather device of the engine, the blow-by gas introduction tube (6) extends from the back surface (18) of the breather case (4) and is fitted into the case communication hole (3), and the tip portion (7) of the introduction tube (6) is inserted. ) To the internal space (8) of the blow-by gas guide passage (2), and the bypass plate (30) is provided between the inlet (5a) on the back side and the outlet (5b) on the top side of the blow-by gas introduction chamber (5). Run in the front-back direction and insert the detour plate (30 The left and right ends in the middle up to look at from the front (30
A breather device for an engine, characterized in that a) is formed in a downward shape, and an oil return port (40) is formed below the tip portion (7) of the blow-by gas introduction cylinder (6). 2. An oil guide groove (17) is formed on the outer peripheral surface of the tip portion (7) of the blow-by gas introducing cylinder (6) in the circumferential direction, and the oil return port (40) and the oil guide groove (17) are formed. The breather device for the engine according to claim 1, characterized in that an oil shielding rib (41) is provided between the breather device and the oil breathing device.