JP2009174385A - Blow-by gas treatment device in internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress increase in a pressure loss in a blow-by gas filter for separating a lubricant from a blow-by gas. <P>SOLUTION: The blow-by gas filter 26 is accommodated in an accommodation chamber 161 inside a head cover 13. A flow channel 28 is formed in a sidewall 17 of the head cover 13. The flow channel 28 is communicated with the accommodation chamber 161. A box-shaped cavity forming machine 30 is arranged in an outer surface of the sidewall 17. There is a cavity portion 31 inside the cavity forming machine 30. An introduction passage 32 is provided so as to penetrate the sidewall 17 and a joining wall 301 of the cavity forming machine 30 jointed to the sidewall 17. The flow channel 28 is communicated with the cavity portion 31 through the introduction passage 32. An inlet 321 of the introduction passage 32 faces to an inflow port 163 of the accommodation chamber 161 across an upper part of the flow channel 28, and an orientation of the inlet 321 of the introduction passage 32 is substantially matched with that of the inflow port 163 of the accommodation chamber 161. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a blow-by gas processing apparatus that returns blow-by gas generated in an internal combustion engine to an intake system for processing.

  In the internal combustion engine, part of the gas in the combustion chamber leaks from the space between the piston and the cylinder wall to the crankcase side as blow-by gas. The blow-by gas contains unburned fuel components and the like, and it is not preferable to discharge the blow-by gas to the outside. Therefore, the blow-by gas is recirculated to the intake system and burned again in the combustion chamber.

  Lubricating oil scatters in the crankcase. Therefore, the blow-by gas returned from the crankcase to the intake system contains mist-like lubricating oil. If the lubricating oil contained in the blow-by gas is sent to the intake system, this lubricating oil component adheres to the intake valve and intake port walls and accumulates as deposits, resulting in poor intake valve operation and sealing. . Moreover, the problem that consumption of lubricating oil becomes early arises.

Therefore, for example, Patent Document 1 discloses a blow-by gas processing apparatus in which lubricating oil contained in blow-by gas is separated before returning to the intake system and returned to the crankcase.
In the devices disclosed in Patent Documents 1 and 2, a filter is provided in the middle of the blow-by gas flow path for flowing blow-by gas into the intake passage. The lubricating oil in the blow-by gas is separated by a filter, and the lubricating oil separated from the blow-by gas is returned into the crankcase.
JP 2002-266620 A JP 2006-152897 A

  When a filter is used to separate lubricating oil from blow-by gas, the separated lubricating oil is held in the filter until it is separated from the filter by the flow of blow-by gas or its own weight. When the engine is running at a low speed and a low load, the flow of blow-by gas is small and the force applied to the filter is small, so that the amount of lubricant retained is large. If the amount of lubricating oil retained is large, the passage of blow-by gas in the filter becomes narrow and pressure loss increases. On the contrary, when the engine speed is high and the load is high, the flow of blow-by gas is large and the force applied to the filter is large, so that the amount of lubricating oil retained is small.

  The pressure loss becomes the largest when the engine speed is suddenly increased from a state where the lubricating oil is held in the filter at a low speed to a high speed. At this time, a large amount of blow-by gas flows while the passage in the filter is narrow and blow-by gas is difficult to flow. Therefore, the pressure loss in the filter increases rapidly and significantly. Such an increase in pressure loss increases the pressure in the crankcase / cylinder head, which may cause leakage of the lubricating oil from the portion sealing them.

  An object of this invention is to suppress the increase in the pressure loss in the blow-by gas filter for isolate | separating lubricating oil from blow-by gas.

  The present invention relates to a blow-by gas processing apparatus in an internal combustion engine comprising a blow-by gas passage for returning blow-by gas generated in the internal combustion engine to an intake system, and a blow-by gas filter provided in the middle of the blow-by gas passage. In the first aspect of the present invention, a hollow portion communicating with the upstream portion of the blow-by gas flow channel upstream of the blow-by gas filter is provided, and the hollow portion and the upstream portion are provided via an introduction passage. Communicate.

The cavity part upstream of the blow-by gas filter suppresses an increase in pressure loss in the blow-by gas filter.
In a preferred example, the blow-by gas filter is housed in a housing chamber that is part of a blow-by gas flow path, and the upstream portion is upstream of the housing chamber.

In a preferred example, the inlet of the introduction passage is provided at a position facing the inlet in the storage chamber.
The pressure wave generated when the blow-by gas flow that suddenly increased collides with the blow-by gas filter is directed directly from the inlet of the storage chamber to the inlet of the introduction passage. Therefore, the effect of suppressing pressure loss is particularly high.

In a preferred example, the storage chamber is provided in the head cover.
The inside of the head cover is suitable as a location for the blow-by gas filter.
In a preferred example, an oil drain passage is provided in the bottom wall of the formation wall of the cavity.

Since the lubricating oil separated in the hollow portion is discharged through the oil drain passage, the lubricating oil separated in the hollow portion does not accumulate in the hollow portion.
In a preferred example, the introduction passage is formed by an introduction pipe.

  Pressure loss in the blow-by gas filter can be suppressed by appropriately selecting the pipe length of the introduction pipe.

  The present invention has an excellent effect that an increase in pressure loss in a blow-by gas filter for separating lubricating oil from blow-by gas can be suppressed.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1A shows an internal combustion engine 10 of an automobile. A head cover 13 is attached to a cylinder head 12 connected to a cylinder block 11 containing a plurality of pistons (not shown). The head cover 13 is integrally connected to the side wall 14 and the upper wall 15 so as to bulge upward from the upper wall 15, the side wall 14 coupled to the cylinder head 12, the upper wall 15 integrally connected to the side wall 14. The head cover 13 is formed in a shape that opens downward.

  As shown in FIG. 3, the chamber forming housing 16 includes side walls 17 and 18 facing each other and side walls 19 and 20 facing each other. Moreover, as shown in FIG.1 (b), the chamber formation housing 16 is provided with the top wall 21 connected with each side wall 17-20 integrally. A support portion 171 is integrally formed on the inner side of the side wall 17, and an annular attachment portion 22 is integrally formed on the lower portion of the support portion 171 and the side walls 18 to 20. A baffle plate 23 is fastened and fixed to the lower surface of the attachment portion 22 with screws 24, and a bent support plate 25 is placed and fixed on the baffle plate 23. A plurality of through holes 251 are formed in the support plate 25.

  The chamber forming housing 16 is divided into a storage chamber 161 and a circulation chamber 162 by a support plate 25, and a blow-by gas filter 26 is stored in the storage chamber 161. The blow-by gas filter 26 is joined to most of the inner surfaces of the side walls 17 to 20, but a gap 27 is provided between the inner surface of the top wall 21 and the blow-by gas filter 26. A channel 28 is formed in the support portion 171 of the side wall 17. The flow path 28 communicates with the storage chamber 161, and the gap 27 communicates with the space portion 131 below the upper wall 15 via the flow path 28. Blow-by gas generated in the internal combustion engine 10 flows into the space 131.

  The blowby gas that has flowed into the space 131 reaches the blowby gas filter 26 via the flow path 28 and the gap 27. The blow-by gas passes through the blow-by gas filter 26, and the lubricating oil contained in the blow-by gas passing through the blow-by gas filter 26 is separated from the blow-by gas in the blow-by gas filter 26.

  A discharge passage 221 is provided through the attachment portion 22. The discharge passage 221 communicates with an oil pan (not shown) attached to the lower part of the cylinder block. The lubricating oil separated in the blow-by gas filter 26 is returned to the oil pan from the discharge passage 221 via the through hole 251 and the circulation chamber 162.

  An outflow passage 29 is formed in the support portion 171. The outflow passage 29 communicates with an intake passage (not shown), and the circulation chamber 162 communicates with the intake passage through the outflow passage 29. The blow-by gas that has passed through the blow-by gas filter 26 is returned to the intake system (not shown) via the through hole 251, the circulation chamber 162, and the outflow passage 29.

  The flow path 28, the storage chamber 161, the circulation chamber 162, and the outflow passage 29 constitute a blow-by gas flow path for returning blow-by gas generated in the internal combustion engine 10 to the intake system. The flow path 28 is an upstream portion of the blow-by gas flow path upstream of the storage chamber 161.

  A box-shaped cavity forming device 30 is disposed on the outer surface of the side wall 17. A cavity 31 is formed in the cavity former 30. An introduction passage 32 is provided through the joining wall 301 and the side wall 17 of the cavity forming device 30 joined to the side wall 17. The flow path 28 communicates with the cavity 31 through the introduction passage 32. The inlet 321 of the introduction passage 32 faces the inflow port 163 of the accommodation chamber 161 across the upper portion of the flow path 28, and the orientation direction of the inlet 321 of the introduction passage 32 and the inflow port 163 of the accommodation chamber 161 are substantially the same. Match.

The passage sectional area of the introduction passage 32 is constant, and the passage sectional area of the flow path 28 is constant. The passage sectional area of the introduction passage 32 is smaller than the passage sectional area of the flow path 28.
When the engine speed rapidly increases from a low speed to a high speed, the blowby gas flow rate increases rapidly, but a part of the rapidly increased blowby gas flow flows into the cavity 31.

In the present embodiment, the following effects can be obtained.
(1) In the absence of the cavity forming device 30, the blowby gas flow that suddenly increases as the engine speed rapidly increases flows directly from the flow path 28 into the accommodating chamber 161, and the blowby gas filter 26 is allowed to enter the unit time per unit time. The blow-by gas flow that is about to pass through increases rapidly. Therefore, the increase in pressure loss in the blow-by gas filter 26 becomes excessive. Since the hollow portion 31 communicates with the flow path 28, which is the upstream portion of the storage chamber 161, via the introduction passage 32, a part of the blow-by gas flow that suddenly increases as the engine speed rapidly increases is Flows into the section 31. The configuration in which a part of the blow-by gas flow that suddenly increases as the engine speed rapidly increases flows into the cavity 31 suppresses an increase in pressure loss in the blow-by gas filter 26.

  (2) The orientation direction of the inlet 321 of the introduction passage 32 and the inflow port 163 of the storage chamber 161 substantially coincide. Therefore, the pressure wave generated when the rapidly increased blow-by gas flow collides with the blow-by gas filter 26 enters the cavity 31 directly from the inlet 163 of the storage chamber 161 to the inlet 321 of the introduction passage 32. This particularly increases the pressure loss suppression effect.

(3) The inside of the head cover 13 is suitable as a place where the blow-by gas filter 26 is disposed, and the outer surface of the head cover 13 is suitable as a place where the cavity forming device 30 is disposed.
(4) In an automobile in which it is not uncommon for the engine speed to rapidly increase from a low speed to a high speed, a sudden increase in blow-by gas flow is not uncommon. Therefore, the present invention is particularly suitable for application to an internal combustion engine of an automobile.

Next, each embodiment of FIGS. 3 to 5 will be described. In each embodiment, the same reference numerals are used for the same components as those in the first embodiment, and detailed description thereof is omitted.
In the second embodiment shown in FIG. 3, an oil drain passage 33 communicating with the cavity 31 is provided through the bottom wall 302 of the cavity former 30 and the upper wall 15 of the head cover 13. The oil drain passage 33 communicates with the space 131, and the cavity 31 communicates with the space 131 via the oil drain passage 33.

  Even in the hollow portion 31, the lubricating oil in the blow-by gas may be separated from the blow-by gas, and the lubricating oil separated from the blow-by gas in the hollow portion 31 falls to the bottom of the hollow portion 31. If the lubricating oil accumulates in the hollow portion 31, the function of the hollow portion 31 for suppressing a rapid increase in pressure loss in the blow-by gas filter 26 is lowered.

The lubricating oil that has fallen to the bottom of the cavity portion 31 flows out from the oil drain passage 33 to the space portion 131, so that the lubricating oil separated from the blow-by gas in the cavity portion 31 does not accumulate in the cavity portion 31.
In the third embodiment of FIG. 4, a cavity former 30 </ b> A having an open cross-sectional shape is joined to the upper wall 15 and the side wall 17, and is surrounded by the cavity former 30 </ b> A, the upper wall 15, and the side wall 17. A cavity 31A is formed. A mounting hole 172 is provided in the side wall 17 as a forming wall of the hollow portion 31 </ b> A, and an introduction pipe 34 is fitted in the mounting hole 172. An oil drain passage 33A is provided through the upper wall 15 which is a forming wall of the hollow portion 31A. The introduction port 341 of the introduction pipe 34 faces the inflow port 163 of the chamber forming housing 16. The passage sectional area in the introduction pipe 34 is smaller than the passage sectional area of the flow path 28.

  The pressure loss in the blow-by gas filter 26 can be further appropriately suppressed by appropriately selecting the pipe length of the introduction pipe 34. That is, the introduction pipe 34 is preferably used in order to enhance the function of the cavity forming device 30A as a resonator.

  In the fourth embodiment of FIG. 5, a cavity former 30 </ b> B having an open cross-sectional shape is joined on the top wall 21 of the chamber forming housing 16, and the cavity surrounded by the cavity former 30 </ b> B and the ceiling wall 21. A portion 31B is formed. An introduction hole 211 is provided through the top wall 21, and the cavity portion 31 </ b> B communicates with the gap 27 through the introduction hole 211. The gap 27 is an upstream portion upstream from the blow-by gas filter 26.

  The introduction hole 211 as the introduction passage serves to introduce a part of the suddenly increased blow-by gas flow into the cavity 31B, and to remove oil for discharging the lubricating oil separated from the blow-by gas at the cavity 31B to the gap 27. Play the role of passage.

In the present invention, the following embodiments are also possible.
In the first embodiment, the introduction passage 32 may be provided at a position away from the position facing the inflow port 163 of the storage chamber 161.

The head cover 13 and the cavity former may be integrally formed.
A hollow portion may be provided so as to surround the flow path 28.
O An oil drain passage for draining the lubricating oil in the hollow portion may communicate with the circulation chamber 162 in the head cover 13.

A blow-by gas filter 26 may be provided outside the head cover 13.
The passage area of the introduction passage 32 and the introduction pipe 34 may be larger than the passage area of the flow path 28.

The cavity former 30 may not be box-shaped.
The technical idea that can be grasped from the embodiment described above will be described below.
[1] The blow-by gas processing apparatus for an internal combustion engine according to any one of claims 1 to 6, wherein the internal combustion engine is an internal combustion engine of an automobile.

1 shows a first embodiment, (a) is a partially omitted side sectional view. (B) is a partial expanded side sectional view. The AA sectional view taken on the line of Fig.1 (a). The partial expanded side sectional view which shows 2nd Embodiment. The partial expanded side sectional view which shows 3rd Embodiment. The partial expanded side sectional view which shows 4th Embodiment.

Explanation of symbols

  10: Internal combustion engine. 13: Head cover. 161: A storage chamber constituting a blow-by gas flow path. 163 ... Inlet. 211... Introduction hole as an introduction passage. 26 ... Blow-by gas filter. 27: A gap that is an upstream portion. 28: A flow path as an upstream portion constituting the blow-by gas flow path. 302: Bottom wall. 31, 31A, 31B ... hollow part. 32 ... Introduction passage. 321 ... Entrance. 33, 33A: Oil drain passage. 34: An introduction pipe forming an introduction passage.

Claims (6)

In a blow-by gas processing apparatus in an internal combustion engine comprising a blow-by gas flow path for returning blow-by gas generated in the internal combustion engine to the intake system, and a blow-by gas filter provided in the middle of the blow-by gas flow path,
A blow-by gas in an internal combustion engine in which a hollow portion communicating with an upstream portion of the blow-by gas flow channel upstream of the blow-by gas filter is provided, and the hollow portion and the upstream portion communicate with each other via an introduction passage. Processing equipment.   2. The blow-by gas processing apparatus for an internal combustion engine according to claim 1, wherein the blow-by gas filter is housed in a housing chamber that is a part of a blow-by gas flow path, and the upstream portion is upstream of the housing chamber.   The blow-by gas processing apparatus for an internal combustion engine according to claim 2, wherein an inlet of the introduction passage is provided at a position facing an inlet of the storage chamber.   The blow-by gas processing apparatus for an internal combustion engine according to claim 2, wherein the storage chamber is provided in a head cover.   The blow-by gas processing apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein an oil drain passage is provided in a bottom wall forming the hollow portion.   The blow-by gas processing apparatus for an internal combustion engine according to any one of claims 1 to 5, wherein the introduction passage is formed by an introduction pipe.

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