JPH11200832A - Blowby gas reducing device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To collect oil mist in blowby gas discharged from an engine. SOLUTION: In a blowby gas reducing device in which a high pressure passage 5 communicating with a cylinder body side faces to the outside around an inlet part 3 to a low pressure passage 2 communicating with an intake manifold side, and in which one side face of an opening and closing valve 6 of a thin elastic material having a substantially flat side view in nonload condition is brought into contact with the inlet part 3 to the low pressure passage 2, a collision wall 7 projected to a space part side corresponding to the high pressure passage 5 is provided in one side face of the valve 6.

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 reducing device for an engine. This invention captures lubricating oil floating in a mist state when the internal pressure of the crankcase of the engine, which is an internal combustion engine, rises during operation and escapes to the intake manifold side, which is a low pressure side, to reduce escape to the outside. Is what you do.

[0002]

2. Description of the Related Art At first, a filter is provided in a breather device which is provided at the head of an engine and is open to the atmosphere to reduce the amount of lubricating oil discharged from blow-by gas. Some lures catch part of the lubricating oil, and some provide supplements by providing a labyrinth partition wall in the breather path. However, the release of these blow-by gases to the atmosphere has not been recognized in recent years because of the air pollution, and the blow-by gases have been flown to the intake manifold side to be reused as part of the intake air.

However, in such a configuration in which the blow-by gas containing the lubricating oil flows through a part of the intake air, when the fuel cut is performed to stop the engine as a diesel engine, the lubricating oil contained in the blow-by gas is If the gas flows into the combustion chamber and burns, the engine cannot be stopped quickly, and the engine stop is delayed for several seconds, resulting in a poor driving feeling.

[0004] For this reason, the breather device must discharge only the gas without escaping the lubricating oil. Japanese Unexamined Patent Publication No. Hei 8-
No. 177449. This known configuration is provided with prediction means for predicting the oil suction amount in advance, and attempts to control the flow rate of the blow-by gas flowing through the breather pipe by the prediction means. there were.

[0005]

SUMMARY OF THE INVENTION The present invention is to solve such a problem of a conventional product, and has taken the following technical means. That is, a high-pressure passage 5 communicating with the cylinder body 4 side is provided outside the inlet 3 to the low-pressure passage 2 communicating with the intake manifold 1 side.
In the blow-by gas reducing mechanism, in which one side of an on-off valve 6 made of a thin elastic material having a substantially flat plate shape in a side view is brought into contact with the inlet 3 to the low-pressure path 2 in a no-load state. The structure of the blow-by gas reducing device for an engine, characterized in that a collision wall 7 protruding toward the corresponding space portion of the high-pressure path 5 is provided on one side surface of the engine.

[0006]

FIG. 1 shows a blow-by gas reducing device 8 provided on a head cover 11 of a diesel engine 10;
The details will be described below. First, the entire engine 10 will be described. An oil pan 12 is mounted below a cylinder body 4 as a main body, a cylinder head 13 and a head cover 11 are mounted above, a front is covered with a gear case 15, and a crankshaft 16 is disposed in front of the gear case 15. A lower pulley 17, an upper pulley 19 for a water pump 18, and a cooling fan 20 are protrudingly provided. Reference numeral 21 denotes a flywheel, which is attached to the crankshaft 16 at the rear end of the engine 10 and protrudes rearward of the engine 10. A rectangular box-shaped case 22 having an open upper portion for attaching the injection pump 14 to the front side of the cylinder body 4 is integrally provided on the side.

A lower end of the intake manifold 1 is attached to the side of the cylinder head 13, and an air cleaner 23 is mounted on a protruding upper end of the intake manifold 1.
Is attached. Reference numeral 24 denotes an intake port. The air taken in from the intake port is filtered by a filter 25 inside the air cleaner 23, and is taken into each cylinder (not shown) through the intake manifold 1 to be used as combustion air.

On the ceiling of the head cover 11, a blow-by gas reducing device 8 mainly comprising an on-off valve 6 having a circular shape in plan view.
It has. The on-off valve 6 is made of an elastic material such as rubber material or soft plastic, and has a substantially flat diaphragm-like one-side pressing surface 9 when no load is applied, and a cylindrical shape projecting downward from a circular central portion. And a projection 26. Further, a plurality of collision walls 7 which are circumferential ribs and protrude in the same direction on a radius centered on the cylindrical projection 26 are provided.

As shown in FIGS. 1 and 2, the head cover 1
1, the edge of the circular on-off valve 6 is placed on a mounting surface seat 27 opened to the ceiling portion, and is clamped from above by a cap 28, and attached via bolts or screws (not shown). . A small hole 29 is opened in the cap 28 so that the diaphragm-like opening / closing valve 6 can easily move upward. A high-pressure passage 5 communicating with the cylinder body 4 side is provided with a blow-by gas that is pressurized by movement of a driving rotating unit (not shown) such as a combustion blow-by gas in a crankcase below the cylinder body 4 and a balance weight of the piston and the crankshaft 16. Both gases are working. The gas pressure in the high-pressure path 5 acts on the outer peripheral side of the substantially flat pressing surface 9 of the on-off valve 6 as shown by an arrow “a”. On-off valve 6 when no load
A cylindrical projection 26 provided at the center of the pressing surface 9 on one side is engaged with the inlet 3 of the low pressure passage 2 as shown in FIG. And the low pressure passage 2 are closed.

Outside the cylindrical projection 26 of the on-off valve 6,
As shown in FIG. 3, a plurality of collision walls 7 are protruded concentrically. When the pressure in the high-pressure passage 5 exceeds the closing force of the on-off valve 6, the blow-by gas pushes the on-off valve 6 upward as shown by the arrow "b" in FIG. Flows to At this time, since the blow-by gas comes into contact with the collision wall 7 as shown by an arrow "c", the stronger the gas flow, the more outside the inlet portion 3 of the low-pressure path 2 in which the oil particles contained in the blow-by gas are upright. The liquid droplets adhere and separate around the cylinder wall 30, and fall as oil droplets toward the lower cylinder body 4 as shown by the arrow “d”, and return into the oil pan 12 at the lower end.

As shown in FIG. 4, the outlet side of the low-pressure passage 2 is mounted in the middle of the intake manifold 1, and the blow-by gas is sent into the combustion chamber on the cylinder side together with the outside air taken into the engine 10. During operation, the low pressure passage 2 becomes one atmosphere or less due to the negative pressure of the air flowing through the intake manifold 1, and sucks the on-off valve 6 to the closed side. The blow-by gas acting on the high-pressure passage 5 contains mist-like lubricating oil. When the on-off valve 6 opens as shown by the arrow “C” and the gas containing mist-like lubricating oil is sent into the combustion chamber, the oil Even if consumption increases or fuel cuts to stop the engine,
Since the lubricating oil contained in the blow-by gas flows into the combustion chamber and the combustion continues, and the engine cannot be stopped immediately, it is better to return the mist-like lubricating oil in the blow-by gas to the oil pan 12 as much as possible.

The configuration shown in FIGS. 5 and 6 is another configuration for recovering the mist-like lubricating oil in the blow-by gas, and the following description will focus on parts different from the first embodiment. On one side surface of an opening / closing valve 6a held and held by a mounting surface seat 27a provided on the upper surface of the head cover 11a and a cap 28a,
A cylindrical projection 26a that projects downward is provided.
The projection 26a has a large diameter, and when no load is applied or when the low-pressure path 2 has a negative pressure, the lower surface of the protruding tip is replaced with the upper surface 3 of the cylindrical cylindrical wall 30a constituting the inlet 3 of the low-pressure path 2.
Press on 1.

The upper surface 31 has a groove 3 having a predetermined depth all around.
2 is provided, and a drop port 33 is provided in at least one portion of the groove 32.
have. When the pressure of the blow-by gas acting on the pressing surface 9a, which is one side surface of the on-off valve 6a, increases through the high-pressure path 5, and the on-off valve 6a is pushed up, the blow-by gas is released from the cylindrical wall 30.
a Flows from the inlet 3 at the upper end to the low pressure passage 2. At this time, since the flow of the blow-by gas changes its direction by 180 degrees on the lower surface of the on-off valve 6a, the mist-like lubricating oil contained in the blow-by gas is captured by the groove 32 provided on the upper surface 31 of the cylindrical tube wall 30a. The oil accumulated in the groove 32 returns to the cylinder body 4 through the drop port 33.

Although the oil recovery mechanism of the second embodiment shown in FIGS. 5 and 6 may be constituted independently, the oil recovery mechanism of the second embodiment is different from the one in which the on-off valve 6 described in the first embodiment is provided with the collision walls 7, 7. In the case of a composite structure, the performance of collecting the mist-like lubricating oil in the blow-by gas is further improved. The one shown in FIG.
b, measure the amount of oil in the oil pan 12 attached to the lower part,
This is another configuration around the oil inspection rod 34.

The point that the blow-by reduction device 8b is provided between the high-pressure path 5 and the low-pressure path 2 is the same. The second oil separator 36 is provided in the low-pressure passage 2 which is the blow-by gas passage of the blow-by reduction device 8 shown in the first embodiment or the second embodiment. In the illustrated example, the second oil separator 36 is provided inside the head cover 11b. Oil is separated by a plurality of baffle plates provided,
The low-pressure blow-by gas flows from the engine 10 to the second oil separator 36 provided separately and downstream, and then reaches the intake manifold 1 via the outlet passage 37. The second oil separator 36 is provided with a filter 38 such as a steel wool or a mesh. The mist-like oil captured here accumulates at the bottom and becomes oil drops in a low-pressure channel 39 attached to the bottom. And fall.

On the other hand, a cylindrical oil reservoir 41 is attached to an opening 40 provided at an appropriate position of the cylinder body 4. The lower end of the low-pressure channel 39 is connected to the oil reservoir 41. When the engine 10b is operated, the opening 40 is closed by the seal 42 of the oil inspection rod 34, and the oil inspection rod 3
4 and the oil in the oil sump 41
Get in. Reference numeral 43 denotes a dustproof cover, which covers the upper surface of the oil reservoir 41.

When such an oil separator is provided in the low-pressure passage 2, the amount of oil released from the blow-by gas can be extremely reduced, and low-pressure return oil is introduced into the cylinder body 4 when the engine 10 is stopped. Since the oil can be naturally dropped, the return oil can be returned to the oil pan 12 without blowing back if the capacity of the oil reservoir 41 has a margin.

[0018]

As described above, according to the present invention, the cylinder body 4 is located outside the inlet 3 to the low pressure passage 2 communicating with the intake manifold 1 side.
Blow-by gas having a high-pressure passage 5 communicating with the side of the valve and facing an inlet 3 to the low-pressure passage 2 with one side of an on-off valve 6 made of a thin elastic material having a substantially flat plate shape in a side view in a no-load state. In the reduction mechanism, a collision wall 7 is provided on one side surface of the on-off valve 6 so as to project toward the space corresponding to the high-pressure path 5. When high gas acts on the pressing surface of the on-off valve to open the on-off valve and try to escape to the intake manifold side, the oil mist in the blow-by gas strongly contacts the collision wall and is captured, resulting in oil droplets. Since it returns to the oil pan side via the cylinder body, consumption of lubricating oil can be reduced.
In addition, since oil mist in the blow-by gas flowing to the intake manifold side is reduced, overrun when the engine is stopped is less likely to occur.

[Brief description of the drawings]

FIG. 1 is a side cross-sectional view of an entire main part when an on-off valve is opened.

FIG. 2 is a side cross-sectional view of the entire main part when the on-off valve is closed.

FIG. 3 is a side sectional view and a bottom view of an on-off valve as a main part.

FIG. 4 is a side view of the entire engine.

FIG. 5 is a side sectional view of a main part of another example of FIG. 2;

FIG. 6 is a plan view of a main part of FIG. 5;

FIG. 7 is a side sectional view of the entire engine of another example shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intake manifold 2 Low pressure path 3 Inlet part 4 Cylinder body 5 High pressure path 6 On-off valve 7 Collision wall

Claims (1)

[Claims] 1. A high pressure passage 5 communicating with a cylinder body 4 is located outside a center of an inlet 3 to a low pressure passage 2 communicating with an intake manifold 1 side.
In a blow-by gas reduction mechanism in which a side surface of the on-off valve 6 made of a thin elastic material having a substantially flat plate shape in a side view in an unloaded state is brought into contact with the inlet portion 3 of the high-pressure passage 5 on one side of the on-off valve 6. A blow-by gas reducing device for an engine, comprising a collision wall 7 protruding toward a corresponding space.