JPH06146841A - Blow-by gas separating device for internal combustion engine - Google Patents

Abstract

PURPOSE:To separate oil component from gas effectively without disturbing the flow of blow-by gas. CONSTITUTION:A blow-by gas return flow passage is provided in 8 cylinder head cover. A mesh filter 6 is arranged aslant on the way the blow-by gas return flow passage, and oil component (OC) in blow-by gas (BG) is separated by the mesh filter 6. A plurality of vertical line member 7 which consists of the mesh filter 6 is formed in such a way that an upstream side surface in relation to flow of blow-by gas (BG) of the vertical line member 7 is formed as a groove 9 formed in curved recessed shape, and the groove 9 is provided continuously in vertical direction. It is thus possible to collect oil component (OC) by the groove 9 of the vertical line member 7 easily, and also prevent oil component (OC) which is collected once by the vertical line member from taking away by flow of blow-by gas (BG). And also it is possible to make oil component (OC) collected in the groove 9 flow downward along the groove 9 easily.

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 separation device for separating an oil component from blow-by gas generated in an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, in a ventilating system for a crankcase provided in an internal combustion engine, blow-by gas accumulated inside the crankcase is recirculated to an intake system for re-combustion. That is, the inside of the cylinder head cover communicating with the crankcase and the surge tank of the intake system are communicated with each other by the PCV passage. Here, since the blow-by gas contains an oil component, some devices have been proposed aiming at separating the oil component and returning only the fuel component to the intake system.

For example, the oil mist separating device disclosed in Japanese Utility Model Laid-Open No. 61-128318 has a cylindrical casing, and the inside of the casing is divided into a blow-by gas introducing passage and an oil returning passage by a partition wall. There is. The blow-by gas introduction passage is opened to the crankcase side of the casing, and the oil return passage is joined to the blow-by gas introduction passage on the intake system side. A mesh filter having a shape matching the cross-sectional shape of the passage is arranged in the middle of the blow-by gas introduction passage. When the blow-by gas passes through the blow-by gas introducing passage, the oil mist in the gas is collected by the mesh filter. A one-way valve is provided at one opening of the oil return passage. This one-way valve closes only for the flow in the direction from the crankcase side to the intake system side. Therefore, due to the flow of the blow-by gas, the one-way valve receives pressure to be closed and the oil return passage is closed. Therefore, the pressure of the blow-by gas does not act on the oil return passage toward the intake system side.

[0004]

However, in the above-mentioned prior art, the wire material forming the mesh filter is merely circular in cross section. Therefore, when the blow-by gas passes through the mesh filter, the oil mist once collected by each wire may be carried away from the wire by the flow of the blow-by gas. In order to prevent this, it is conceivable to increase the number of mesh filters or make the mesh filters finer. However, in that case, conversely, the flow path resistance for the blow-by gas becomes large, and the flow of the blow-by gas is obstructed. As a result, the oil mist cannot be sufficiently separated from the blow-by gas, and the oil consumption in the internal combustion engine may be reduced or the exhaust emission may not be improved.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is an internal combustion engine capable of more effectively separating an oil component from a blow-by gas without hindering the flow of the gas. It is to provide a blow-by gas separation device for an engine.

[0006]

In order to achieve the above object, in the present invention, a blow-by for recirculating blow-by gas, which is formed to communicate between a crank case of an internal combustion engine and an intake system, is provided. A gas recirculation passage,
A blow-by gas separator for an internal combustion engine, which is disposed in the middle of the blow-by gas recirculation passage and includes a mesh filter formed of a plurality of wire rods extending in the vertical direction and the horizontal direction, and the oil component in the blow-by gas is separated by the mesh filter. In the apparatus, it is intended that a plurality of wire rods extending in the vertical direction of the mesh filter have concave side surfaces on the upstream side with respect to the blow-by gas flow, and the concave shapes are continuous in the vertical direction.

[0007]

According to the above construction, when the blow-by gas tries to flow through the blow-by gas recirculation passage, the blow-by gas passes through the mesh filter and the oil component in the gas is collected by each wire. At this time, since the upstream side surface of each wire extending in the vertical direction has a recessed shape, the oil component is easily collected by the upstream side surface, and the oil once collected by the wire. No components are carried away by the flow of blow-by gas. In addition, since the upstream side surface of each wire extends in the vertical direction, the oil component collected on the upstream side surface easily flows downward along the same side surface. Moreover, in order to accelerate the collection of the oil component by the mesh filter,
It is not necessary to increase the number of mesh filters or make the mesh filter mesh finer than necessary.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the blow-by gas separating apparatus for an internal combustion engine according to the present invention will be described in detail below with reference to FIGS.

FIG. 4 shows a cylinder head cover 1 of an internal combustion engine.
It is sectional drawing which shows some. As is well known, the cylinder head cover 1 covers a cylinder head (not shown), and the cover 1 constitutes a ventilating system for a crank case (not shown). Further, a part of the blow-by gas recirculation passage 2 is formed inside the cylinder head cover 1, and the passage 2 connects the crankcase and the intake system. Then, blow-by gas accumulated inside the crankcase (indicated as "BG" in FIGS. 2, 3, and 4).
Is returned to the intake system via the inside of the cylinder head cover 1 and re-combusted in a combustion chamber (not shown). It should be noted that one end of a pipe 3 is communicated with the cylinder head cover 1. The other end of the pipe 3 communicates with an intake system upstream of a throttle valve (not shown). And
Through this pipe 3, fresh air in the intake system is introduced into the cylinder head cover 1. or,
An oil reservoir is formed in the cylinder head described above.

Here, oil components such as thick oil and oil mist are contained in the blow-by gas (“O” in FIG. 3).
"C". ) Is contained, it is necessary to separate the oil component and to recirculate only the fuel component to the intake system. Therefore, inside the cylinder head cover 1, the baffle plates 4 and 5 are arranged vertically in two stages. A part of the blow-by gas recirculation passage 2 is formed between the baffle plates 4 and 5. The mesh filter 6 is obliquely arranged and supported between the baffle plates 4 and 5. That is, the mesh filter 6 is obliquely arranged so that its upper side is located upstream with respect to the flow of blow-by gas.

When the blow-by gas passing through the inside of the cylinder head cover 1 passes through the mesh filter 6, the filter 6 separates the oil component in the blow-by gas. Further, the oil components contained in the blow-by gas are separated from the baffle plates 4 and 5 by passing a part of the blow-by gas in contact with the surfaces of the baffle plates 4 and 5.

The structure of the mesh filter 6, which is a characteristic main part of this embodiment, will now be described. Figure 1
2 is an enlarged sectional view showing an arrangement state of the mesh filter 6, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. Is. The mesh filter 6 includes a plurality of vertically extending wire rods (hereinafter simply referred to as “vertical wire rods”) 7 and a plurality of horizontally extending wire rods (hereinafter simply referred to as “horizontal wire rods”) 8.
It is formed with a stitch of a predetermined size. Each horizontal wire 8 has a circular cross section. Further, each vertical wire 7 is arranged in two rows centering on the horizontal wire 8 in the thickness direction of the mesh filter 6, that is, in the flow direction of the blow-by gas. Each vertical wire 7 has a substantially triangular cross section. That is, the upstream side surface of each vertical wire rod 7 with respect to the blow-by gas flow is a groove 9 having a curved concave shape, and the groove 9 is formed continuously in the vertical direction of the vertical wire rod 7. Further, the downstream end of each vertical wire 7 with respect to the blow-by gas flow is a tapered tip 10, and the tip 10 is formed continuously in the vertical direction of the vertical wire 7.

Therefore, as shown in FIG. 4, when the blow-by gas flows inside the cylinder head cover 1, the blow-by gas passes through the mesh filter 6, and the mesh filter 6 collects the oil component in the blow-by gas. It In particular, since each vertical wire 7 has a triangular cross section, as shown in FIG. 2, blow-by gas passing through the mesh filter 6 can easily flow around each vertical wire 7. Become. That is, the flow of blow-by gas is not obstructed by the mesh filter 6. Therefore, the oil component in the blowby gas is not accelerated around each vertical wire 7 and is not accelerated.
Collected by. In particular, since the upstream side surface of each vertical wire 7 with respect to the blow-by gas flow is the curved groove 9,
The groove 9 facilitates the collection of oil components. Further, the oil component once collected in the groove 9 is not carried away by the flow of blow-by gas. And
As shown in FIG. 3, the oil component collected in the groove 9 of each vertical wire 7 flows downward along the groove 9 and is further sent to the oil sump of the cylinder head through the baffle plate 5. . Moreover, in this embodiment, since the mesh filter 6 is obliquely arranged, the oil component collected by each vertical wire 7 easily flows downward, and in that sense, the oil component is easily collected. ing. Further, since the mesh filter 6 is obliquely arranged, the effective area of the mesh filter 6 in the flow path between the upper and lower baffle plates 4 and 5 becomes large, and thereby a large amount of oil component is collected. In addition, the flow path resistance of the mesh filter 6 in the blowby gas recirculation passage 2 is reduced, and the decrease in the flow rate of the blowby gas is reduced.

As described above, in the mesh filter 6 of this embodiment, in order to promote the separation of the oil component by the mesh filter 6, the number of mesh filters 6 is increased or the meshes of the mesh filter 6 are made finer than necessary. The oil component is easily collected simply by its structure and arrangement without causing any trouble. Therefore, the oil component can be more effectively separated from the blow-by gas without hindering the flow of the blow-by gas. As a result, it is possible to improve oil consumption and exhaust emission in the internal combustion engine.

The present invention is not limited to the above-described embodiment, but can be implemented as follows with a part of the configuration appropriately changed without departing from the spirit of the invention. (1) In the above embodiment, the vertical wire rods 7 are arranged in two rows with respect to one row of the horizontal wire rods 8. However, they are arranged in one row, or the vertical wire rods are arranged in three rows with respect to the two horizontal wire rods. You may do it.

(2) In the above embodiment, the vertical wire 7 has a substantially triangular cross section, but the vertical wire may have a semicircular cross section or any other shape. (3) In the above-described embodiment, the upstream side surface of the vertical wire 7 with respect to the blow-by gas flow is the groove 9 having a curved concave shape. However, the upstream side surface of the vertical wire material may be formed into a channel-shaped concave shape. It may have a shape.

[0017]

As described above in detail, according to the present invention, in the mesh filter disposed in the middle of the blow-by gas recirculation passage, a plurality of wire rods extending in the vertical direction are formed with a recess on the upstream side surface with respect to the blow-by gas flow. The shape is made continuous, and the concave shape is continuous in the vertical direction. Therefore, the oil component is easily collected by the upstream side surface of the wire, and the oil component once collected by the wire is not carried away by the flow of the blow-by gas. Further, the oil component collected on the upstream side surface of the wire easily flows downward along the same side surface. As a result, the oil component can be more effectively separated from the blow-by gas without obstructing the flow of the blow-by gas, which in turn can improve the oil consumption amount and exhaust emission in the internal combustion engine. Be effective.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view showing an arrangement state of a mesh filter in an embodiment embodying the present invention.

2 is a cross-sectional view taken along the line AA of FIG. 1 in one embodiment.

FIG. 3 is a perspective view showing, in an enlarged scale, a part of a mesh filter in a cutaway manner according to an embodiment.

FIG. 4 is a cross-sectional view showing a part of a cylinder head cover in one embodiment.

[Explanation of symbols]

1 ... Cylinder head cover, 2 ... Blow-by gas recirculation passage, 6 ... Mesh filter, 7 ... Vertical wire, 8 ... Horizontal wire,
9 ... Groove, BG ... Blow-by gas, OC ... Oil component.

Claims (1)

[Claims] 1. A blow-by gas recirculation passage, which is formed to communicate between a crankcase of an internal combustion engine and an intake system and which recirculates a blow-by gas, is arranged in the middle of the blow-by gas recirculation passage, and is arranged in a vertical direction. And a mesh filter formed of a plurality of wire rods extending in the lateral direction, in a blow-by gas separation device of an internal combustion engine for separating an oil component in blow-by gas by the mesh filter, a plurality of vertically extending mesh filter A blow-by gas separation device for an internal combustion engine, characterized in that a wire rod has a concave side surface on the upstream side with respect to the blow-by gas flow, and the concave shape is continuous in the vertical direction.