JPH0631125Y2 - PCV room for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to the structure of a PCV room of an internal combustion engine, and particularly, to suppress the inflow of oil mixed in blow-by gas into the intake system as much as possible. The structure of the PCV room of the internal combustion engine.

[Prior Art] As a prior art related to the present invention, for example, Japanese Utility Model Publication 44
-28023, JP 52-137542, JP 56-132355, JP 59-1
Japanese Patent No. 79216 and Japanese Utility Model Laid-Open No. 61-88018 are known.

The above-mentioned Japanese Utility Model Publication No. 44-28023 relates to a baffle plate used for a breather mechanism of an internal combustion engine, and a baffle portion around the air vent hole of the breather mechanism from a surface to which oil is applied to a downward surface is baffled. It is covered with a plate and forms a small chamber around the air vent hole for sinking and separating oil droplets floating in the air.

Japanese Unexamined Patent Publication No. 52-137542 discloses a horizontal engine for preventing oil from being blown out from a blazer device when the engine is tilted, and a liquid level of oil is provided in an oil escape hole which connects the blazer chamber and the crank room. An oil stop valve is provided which closes the oil escape hole when it reaches a predetermined position.

Japanese Utility Model Application Laid-Open No. 56-132355 discloses a technique for removing oil mixed in blow-by gas, in which a blow-by gas take-out part is formed in a hermetically sealed state, and a swirl flow is generated in the blow-by gas in the take-out part. An end portion of a connection pipe connected to the air cleaner is arranged at a place where a blow-by gas from which oil is removed by swirling is collected by providing a throttle passage for generating the throttle passage.

Japanese Utility Model Laid-Open No. 59-179216 discloses that by completely separating the blow-by gas reducing system path from the oil return system path from the rocker cover, the effect of the blow-by gas flow on the oil return is eliminated, and the oil return And prevents the occurrence of problems such as oil spray.

Japanese Utility Model Laid-Open No. 61-8801 relates to a PCV device for an engine in which a cylinder axis line is substantially horizontal or inclined, and a PCV chamber for introducing blow-by gas is provided by using a recess on the upper surface of the engine. Water and oil are prevented from accumulating in the recess.

As can be seen from these conventional techniques, during engine operation, the oil in the crankcase is agitated by the vertical movement of the piston and the rotation of the crankshaft, and the oil is severely scattered in the crank chamber. In this case, since a large amount of oil is mixed in the blow-by gas in the crank chamber, it is not appropriate to let this flow into the PCV room as it is from the viewpoint of reducing oil consumption.

Therefore, as shown in FIG. 7, the oil directly flows into the PCV room 1 in front of the separator 2 forming the PCV room 1.
A structure in which the full-scale separator 3 is attached to prevent the inflow to the above is considered. With such a structure, the blow-by gas G flows from the lower end side of the front separator 3, and the oil O scattered by the rotation of the crankshaft is prevented from directly flowing into the inflow port 4 of the PCV room 1. As a result, the oil separation ability is enhanced.

[Problems to be solved by the invention] However, in this structure, when the engine speed is in the middle and high rotation range, the amount of oil adhered to the inner wall surface of the crankcase and the front separator 3 increases, and the PCV room 1 does not have a large amount of oil. The problem arises that the inflow of oil increases significantly.
That is, in this structure, in order to guide the blow-by gas in the crankcase to the PCV room, the blow-by gas breaks through the film-shaped oil O ₁ flowing from the front separator 3 and flows into the PCV room. The problem arises that a large amount of oil is carried away by the gas stream. Therefore, at high engine speed, P
There was a problem that oil was collected in the CV room, and this oil was pushed out by the internal pressure of the crankcase and was blown out to the intake side.

Similar to the above-mentioned structure, a plate-shaped separator was provided in front of the separator formed in the PCV room over almost the entire cross section of the crankcase, and a method of guiding blow-by gas from the end of the separator to the PCV room was also tried. However, although the oil was prevented from directly flowing into the inlet of the PCV room, there was almost no effect of reducing the amount of oil carried away or the amount of oil blown out.

In consideration of the above problems, the present invention significantly reduces the oil consumption due to the removal of blow-by gas oil, and can reliably prevent the oil from being blown into the intake system during normal operation. The purpose is to provide.

[Means for Solving the Problems] A PCV room of an internal combustion engine according to the present invention for this purpose is an internal combustion engine in which blow-by gas in a crank chamber is returned to an intake system through the PCV room. An inlet for introducing blow-by gas into the PCV room is provided above the first separator partitioning the PCV room, and the first separator and the first separator are provided on the crankshaft side of the first separator. A space portion formed by an adjacent second separator is formed, the space portion is formed as a passage for guiding blow-by gas in the crank chamber to the inflow port, and a flow passage cross-sectional area of the space portion is in the blow-by gas. The oil in the second separator is set to a size that allows it to sink and separate, and is sprinkled on the crankshaft side of the second separator by the rotation of the crankshaft or the like. It is provided with a canopy portion that changes the flow direction of the oil scattered and attached to the second separator to prevent the oil from the second separator from dropping to the inflow portion of the blow-by gas into the space portion.

[Operation] In the PCV room of the internal combustion engine configured as described above, as the engine speed increases, the amount of oil scattered due to stirring of the crankshaft increases accordingly, and the crank chamber inner wall and the second A large amount of oil adheres to the separator. That is, a thick oil layer is formed on the crank chamber inner wall and the second separator, and this oil flows down along the wall surface.

In this case, on the crankshaft side of the second separator, there is an eaves portion that prevents the oil that is scattered by the rotation of the crankshaft and that adheres to the second separator from falling into the inflow portion of the blow-by gas into the space. Since it is provided, the oil flowing down along the second separator does not reach the inflow portion of the blow-by gas and is guided in another direction. In other words, the eaves function as a gutter provided under the eaves. Therefore, even when the blow-by gas passes under the second separator and flows down to the space side, the blow-by gas is prevented from colliding with the film-like oil flowing down from the second separator, and the oil is taken away by the blow-by gas. The quantity is reduced.

Next, the blow-by gas that has passed below the second separator will flow into the space formed between the first separator and the second separator, but the flow passage cross-sectional area of this space is Since the oil can be drained sufficiently, the oil mixed in the blow-by gas is further removed in this space. Since the inlet of the PCV room is provided above the first separator, that is, the distance between the inflow portion of the blow-by gas into the space and the inlet of the PCV room is sufficiently long. Therefore, the effect of removing oil in the space is remarkably enhanced, and the oil layer is not dragged around the PCV room inlet.

Therefore, the amount of oil flowing into the PCV room is significantly suppressed as compared with the conventional structure, the amount of oil carried away is significantly reduced, and the oil is reliably prevented from being blown out to the intake side during normal operation. .

[Embodiment] Hereinafter, a preferred embodiment of a PCV room structure of an internal combustion engine according to the present invention will be described with reference to the drawings.

First Embodiment FIGS. 1 to 5 show a first embodiment of the present invention, particularly when it is applied to a lying-down cylinder in which the cylinder axis is substantially horizontal or inclined. First
In the figure, reference numeral 11 denotes a cylinder block, and a piston 12 is slidably fitted in a cylinder bore of the cylinder block 11. A cylinder axis A connecting the center of the piston 12 and the center of the crankshaft 13 is inclined by an angle θ with respect to a horizontal axis B passing through the center of the crankshaft 13, and the center of the piston 12 is slightly above the horizontal axis B. positioned. Piston 12 is connecting rod 14
Is connected to the crankshaft 13 via. In this case, the crankshaft 13 is adapted to rotate in the same direction as the clockwise direction as shown by the arrow in FIG. A cylinder head 15 is located on one side of the cylinder block 11, and an oil pan 16 that collects oil for lubricating each lubrication part of the engine is arranged directly below a side surface that is a lower surface of the cylinder block 11. Has been done. The oil in the oil pan 16 is supplied to the valve operating system on the cylinder head 15 side by an oil pump (not shown).

A crankcase 17 is attached to the other side of the cylinder block 11. The crankcase 17 covers the other side of the cylinder block 11, and the crankcase 17 and the cylinder lock 11 form a crank chamber 18. A part of the upper portion of the crankcase 17 bulges outward, and a plate-shaped first separator 19 extending vertically is attached to the inside of the bulging portion 17a. The first separator 19 constitutes a PCV (positive crankcase ventilation) room 20 together with the bulging portion 17a of the crankcase 17. That is, the PCV room 20 and the crank chamber 18 are partitioned by the first separator 19. At the uppermost part of the first separator 19, a square inlet 21 into which blow-by gas flows is formed.

On the crankshaft 13 side of the first separator 19, a plate-shaped first plate extending substantially obliquely upward along the rotation locus of the counterweight 13a of the crankshaft 13 (or the rotation locus C of the large end 14a of the connecting rod 14). Two palator 22 is provided. That is, the second separator 22
Are obliquely attached to the first separator 19. The vertical width of the second separator 22 is smaller than the vertical width of the first separator 20, and the lower end surface 22a of the second separator 22 is located above the cylinder axis A. .

Between the first separator 19 and the second separator 22,
The space portion 23 is formed, and the space portion 23 is open only at the lower side. The space portion 23 is configured as a passage for guiding the blow-by gas G in the crank chamber 18 to the inflow port 21 of the PCV room 20, and the flow passage cross-sectional area thereof is the blow-by gas G.
The oil mixed in the oil is set to a size that allows sedimentation and separation. That is, in the space portion 23, the flow velocity of the blow-by gas is sufficiently reduced so that the oil mixed in the blow-by gas is sunk by gravity and separated from the blow-by gas.

On the crankshaft 13 side of the second separator 22, an eaves-shaped portion 24 formed in a V shape is provided. The eaves portion 24 projects toward the crankshaft 13, and the top portion 24a thereof is located above the lower end surface 22a of the second separator 22. Both ends 24b, 24c of the second separator 22 are
The second separator 22 is located on both left and right end surfaces, and its tip is located below the lower end surface of the second separator 22. The top portion 24a of the eaves portion 24 is aligned with the center of the bearing cap 25 that holds the crankshaft 13 shown by the chain double-dashed line in FIG. This is to reduce the oil scattering speed in the vicinity of the top portion 24a of the eaves portion 24, and to prevent a large amount of oil from flowing down to the top portion 24a of the eaves portion 24. The eaves portion 24 is joined to the second separator 22 by welding.

FIG. 5 shows the PCV when the first separator 19 is removed.
The shape of room 20 is shown. As shown in the figure, at the center of the PCV room 20, a baffle plate extending downward from the top surface is provided.
26 is formed, and this baffle plate 26 constitutes a maze. The PCV room is on the downstream side of the PCV room 20.
An outlet 27 is provided to allow the blow-by gas G flowing into 20 to flow into the intake side (intake manifold). An opening 30 is formed in the lower portion of the first separator 19, and a pipe 31 for returning the oil accumulated in the PCV room 20 to the oil pan 16 is connected to the opening 30.

Reference numeral 32 in FIGS. 2 and 3 denotes an oil supply port formed in the crankcase 17. In this embodiment,
The first separator 19 and the second separator 22 are screw
Although it is fixed to the crankcase 17 by 33, it may be fixed by a means instead of this.

Next, the operation of the first embodiment will be described.

When the engine speed reaches the middle and high speed range, the piston 1
2. The high-speed movement of the connecting rod 14 and the crankshaft 13 vigorously agitates the oil returned from the cylinder head 15 side. Therefore, the oil is significantly scattered in the crank chamber 18, the scattered oil adheres to the inner wall surface forming the crank chamber 18, and the inner wall surface is covered with a thick oil layer. The oil attached to the inner wall is
It flows down along the wall surface and flows into the oil pan 16. In this case, the crankshaft of the second separator 22
Although a large amount of oil adheres to the 13 side, since the second separator 22 is provided with a V-shaped eaves portion 24, the oil O flowing down along the second separator 22 is As shown by the arrow in FIG. 2, the part where the blow-by gas G flows into the space part is not covered with oil because it is guided to both sides along the inclined surface of the eaves part 24. This prevents the blow-by gas G from colliding with the oil film as shown in FIG. 7, and the amount of oil carried away by the blow-by gas G is greatly suppressed.

The flow velocity of the oil flowing into the space 23 is significantly reduced as compared with the conventional structure. In other words, since the space 23 has a sufficiently large flow passage cross-sectional area, the flow velocity of the blow-by gas G is reduced to a flow velocity at which sufficient oil cutting can be performed, and the oil mixed in the blow-by gas G is gravitated. Settled and separated. Further, since the inflow port 21 of the PCV room 20 is located at the uppermost part of the first separator 19, the length of the space 23 is sufficiently secured, and the oil separation effect is enhanced.

The blow-by gas G that has passed through the space 23 flows into the PCV room 20 via the inflow port 21, passes below the baffle plate 26, and reaches the outflow port 27, as shown in FIG. Since the PCV room 20 constitutes the maze by the baffle plate 26, the oil separation capability is further enhanced.

In this way, the eaves part 24, the space part 23, the inflow port 21, the baffle plate
By the action of 26, the amount of oil taken away by the blow-by gas G can be suppressed to an extremely small amount, and the amount of oil consumption can be remarkably reduced. Further, as a result, the amount of oil accumulated in the PCV room 20 becomes extremely small, and it is possible to reliably prevent the oil from being blown out to the intake side during normal operation.

Second Embodiment FIG. 6 shows a second embodiment of the present invention. The second embodiment is different from the first embodiment only in the structure of the eaves portion attached to the second separator, and the other portions are the same as those in the first embodiment, so the description of the corresponding portions will be omitted and different. Only the part will be described.

In FIG. 6, the second separator 22 has an eaves portion 24.
And the eaves portion 41 are attached, and the eaves portion 41 is the first
The eaves portion is newly provided for the embodiment.
Located just above 24. The eaves portion 41 is formed in a strip plate shape, which is different from the shape of the eaves portion 24 described above, and is arranged so as to be inclined so that the oil that flows down flows to the right end surface side of the second separator 22.

In the second embodiment configured in this way, two eaves portions are provided, and even if the amount of oil adhering to the second separator 22 increases, the oil that flows down can be reliably removed by the second separator. It can lead to both sides of 22 and can enhance the ability of oil separation. Other functions are the same as in the first embodiment.

Although each of the above-described embodiments has been applied to the overturned engine, the present invention is not limited to these engines.

[Effect of the Invention] According to the PCV room structure of the internal combustion engine of the present invention, the eaves portion provided on the second separator prevents the blow-by gas from colliding with the oil falling from the second separator, and the flow of the space portion is prevented. By increasing the cross-sectional area of the road to promote the subsidence and separation of the oil mixed in the blow-by gas, it is possible to significantly suppress the amount of the oil taken away by the blow-by gas. Therefore, it is possible to significantly reduce the amount of oil consumption, and it is possible to significantly increase the limit rotational speed of the oil blown out to the intake side, which ensures the oil blowout to the intake side during normal operation. Can be prevented.

[Brief description of drawings]

1 is a sectional view of the internal combustion engine according to a first embodiment of the present invention in the vicinity of a PCV room, FIG. 2 is a front view of the PCV room in FIG. 1, and FIG. 3 is a line III-III in FIG. Fig. 4 is a perspective view of the crankcase in Fig. 1, Fig. 5 is a perspective view of the PCV room when the first separator is removed from the apparatus of Fig. 1, and Fig. 6 is a perspective view of the present invention. FIG. 7 is a perspective view showing the vicinity of a PCV room of an internal combustion engine according to a second embodiment, and FIG. 7 is a sectional view showing an example of a conventional PCV room. 11 …… Cylinder block 13 …… Crankshaft 13a …… Counterweight 16 …… Oil pan 17 …… Crankcase 18 …… Crank chamber 19 …… First separator 20 …… PCV room 21 …… Inlet 22 …… Second separator 23 …… Space part 24, 41 …… Eaves part 26 …… Baffle plate

Front page continuation (72) Inventor Yukio Yoshida 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (56) References JP 59-96469 (JP, A) Actual development Sho 59-179215 (JP , U)

Claims (1)

[Scope of utility model registration request] 1. An internal combustion engine in which blow-by gas in a crank chamber is recirculated to an intake system via a PCV room, and blow-by gas is added to an upper portion of a first separator partitioning the crank chamber and the PCV room. PCV
An inflow port for inflowing into the room is provided, and the first separator and the first separator are provided on the crankshaft side of the first separator.
And a second separator adjacent to the second separator, the space is configured as a passage for guiding blow-by gas in the crank chamber to the inflow port, and the flow passage cross-sectional area of the space is The oil in the blow-by gas is set to a size that allows the oil to sink and separate, and the second separator is changed from the second separator to the crankshaft side of the second separator by changing the flowing direction of the oil scattered and scattered by the rotation of the crankshaft and the like. A PCV room for an internal combustion engine, which is provided with a canopy portion for preventing the oil from falling into an inflow portion of the blow-by gas into the space portion.