JP5223728B2 - Oil mist separator - Google Patents

Description

  The present invention relates to an oil mist separator which is provided on a cylinder head cover of an engine and for removing oil mist contained in blow-by gas in a blow-by gas flow path into droplets in a filter.

  When blow-by gas containing oil mist generated during the operation of an automobile engine is returned to the intake system, the oil mist adheres to and accumulates on intake system components such as the throttle and intake valve, which can cause malfunctions. The oil mist is removed by the oil mist separator, and only the gas is recirculated to the intake passage such as an intake manifold using the negative pressure of the engine and burned. As this type of oil mist separator, a filter type oil mist separator is known in which a filter is disposed in a blow-by gas flow path, and oil mist in the blow-by gas is removed by the filter. For example, it is provided integrally with the engine head cover and has an inlet and an outlet for blow-by gas, and has oil mist separating means inside, the inlet is formed by a downward inlet pipe, and the inlet pipe inner wall has a smaller diameter portion than the larger diameter portion. An oil mist separator to which an annular baffle plate having an inclined wall at a low position is attached has been proposed (see Patent Document 1).

Japanese Utility Model Publication No. 6-76614 (pages 2 and 3)

  However, in the oil mist separator described in Patent Document 1, the oil mist adhering to the filter forms droplets and then accumulates in the lower part of the filter due to its own weight, but a part of the oil accumulated in the lower part of the filter is blowby gas flow. Is scattered again by hitting the lower part of the filter, and is conveyed to the intake passage side by blow-by gas. For this reason, the oil mist is once attached to the filter and separated, but there is a problem that the separation performance is lowered by the amount of re-scattering.

  Accordingly, an object of the present invention is to provide an oil mist separator that can suppress re-scattering of oil accumulated in a filter and improve oil mist separation performance.

In order to achieve the above object, an oil mist separator according to claim 1 is provided with a housing of an oil mist separator having a blow-by gas passage on a cylinder head cover of an engine, and a filter fixing frame in the housing. The filter for attaching oil mist contained in blow-by gas to the filter fixing frame and forming droplets is fixed across the blow-by gas flow path. The lower part of the filter fixing frame is formed wider than the upper part and the side part, and an oil discharge hole for discharging oil droplets in the filter is provided on the bottom wall of the housing , The lower portion is characterized in that the height of the upper edge of the lower portion is provided at a position corresponding to the height of the lower end of the inlet for introducing blow-by gas into the housing .

An oil mist separator according to a second aspect of the present invention is the invention according to the first aspect, wherein the filter fixing frame is provided on the upstream side of the filter.
The oil mist separator according to a third aspect of the invention is characterized in that, in the invention according to the second aspect, a through hole is provided in a lower portion of the filter fixing frame.

The oil mist separator according to a fourth aspect of the present invention is the oil mist separator according to any one of the first to third aspects, wherein the flow of blow-by gas at the lower end of the downstream side of the filter is stagnant in the oil discharge hole. It is provided in the site | part which exists.

An oil mist separator according to a fifth aspect of the invention is characterized in that, in the invention according to any one of the first to fourth aspects, the filter is subjected to an oil repellent process.

According to the present invention, the following effects can be exhibited.
In the oil mist separator of the present invention, the lower part of the filter fixing frame is formed wider than the upper part and the side part. For this reason, when oil mist adheres to the filter and forms droplets and accumulates in the lower part of the filter, the blow-by gas flow is blocked by the lower part of the filter fixing frame and does not hit the lower part of the filter. Therefore, re-scattering of the oil accumulated in the lower part of the filter can be suppressed.

  Therefore, according to the oil mist separator of the present invention, re-scattering of the oil accumulated in the filter can be suppressed, and as a result, the oil mist separation performance can be improved.

A longitudinal section showing an oil mist separator in an embodiment. The partial expanded sectional view which shows the filter lower end part vicinity of an oil mist separator. The cross-sectional view which shows an oil mist separator. The perspective view which shows the filter fixing frame and filter which comprise an oil mist separator. The longitudinal cross-sectional view which shows another example of an oil mist separator. The longitudinal cross-sectional view which shows another example of an oil mist separator.

Hereinafter, an embodiment of an oil mist separator embodying the present invention will be described in detail.
As shown in FIG. 1, an oil mist separator 10 that recovers oil from oil mist in blow-by gas flowing through the blow-by gas flow path is provided on a cylinder head cover C provided in the cylinder block of the engine. As shown in FIGS. 1 and 3, the housing 11 of the oil mist separator 10 is formed in a square cylinder shape, and an inlet 12 for introducing blow-by gas is provided at the left end in the figure, and blow-by gas is provided at the right end. Is provided with an outlet 13 for exhausting air. Accordingly, a blow-by gas passage 14 through which blow-by gas flows from the inlet 12 toward the outlet 13 is formed in the housing 11 as indicated by an arrow in the figure.

  A filter fixing frame 15 having a square frame shape as shown in FIG. 4 is arranged at the center position in the flow direction of the blow-by gas in the housing 11, and oil mist in the blow-by gas is attached to the downstream surface thereof. A filter 16 for separating and recovering oil by forming droplets is adhered. The filter fixing frame 15 includes an upper frame 17 on the upper side, side frames 18 on both sides, and a lower frame 19 on the lower side, and the lower frame 19 is formed wider than the upper frame 17 and the side frame 18. That is, the width (height) d of the lower frame 19 is set wider than the width u of the upper frame 17 and the width s of the side frame 18. The width u of the upper frame 17 and the width s of the side frame 18 are set to the same width.

  As shown in FIG. 1, the width d of the lower frame 19 is set so that the upper edge of the lower frame 19 corresponds to the height of the lower end of the blow-by gas inlet 12. As the width d of the lower frame 19 is increased, the effect of shielding the blow-by gas flow by the lower frame 19 increases, but the pressure loss of the blow-by gas flow increases, which is not preferable. The lower frame 19 configured in this manner prevents the oil that has been formed into droplets in the filter 16 from being re-scattered by the flow of blow-by gas.

  The filter 16 is formed of a non-woven fabric made of polyester such as polyethylene terephthalate (PET), but is also formed of other porous metals, porous ceramics, or the like. The filter 16 may be a superposition of a plurality of filter materials. In addition, the filter 16 is subjected to oil repellency processing (water / oil repellency processing), so that oil mist adhering to the filter 16 is easily formed into droplets, and further, the oil that is formed into droplets is easily lowered by its own weight. Yes. The oil-repellent processing of the filter 16 is not particularly limited, but is performed according to a conventional method such as a method in which a compound such as a fluororesin or silicone is infiltrated into the filter 16 and heat-treated at a high temperature.

  As shown in FIGS. 2 and 3, a circular oil discharge hole is formed in the bottom wall 11 a of the housing 11 of the oil mist separator 10 at a portion where the flow of blow-by gas at the downstream lower end position of the filter 16 is stagnant. 20 is formed through. The bottom wall 11a of the housing 11 is formed integrally with the cylinder head cover C. Thus, by providing the oil discharge hole 20 in the stagnation region of the flow of blow-by gas, the oil accumulated at the lower end of the filter 16 is discharged from the oil discharge hole 20 without being obstructed by the flow of blow-by gas. ing. The lower frame 19 of the filter fixing frame 15 is provided with a pair of circular holes 21 so that oil accumulated in the lower portion of the filter 16 is smoothly guided to the oil discharge hole 20. .

Next, the operation of the oil mist separator 10 configured as described above will be described.
Now, the blow-by gas introduced into the housing 11 from the inlet 12 of the housing 11 of the oil mist separator 10 reaches the filter 16 provided at the central position in the housing 11 and passes through the filter 16. At this time, the oil mist in the blow-by gas adheres to the fiber surface in the filter 16 and is formed into droplets there. Dropped oil descends along the fiber surface by its own weight, reaches the lower end in the filter 16 and accumulates there. At this time, since the fibers constituting the filter 16 are subjected to an oil repellency treatment, the formation of droplets of oil mist adhering to the fiber surface is promoted, and the dropletized oil quickly descends the fiber surface. be able to.

  At the lower end of the filter 16, the lower frame 19 of the filter fixing frame 15 is arranged on the upstream side, and the width d of the lower frame 19 is set wider than the width u of the upper frame 17 and the width s of the side frame 18. Has been. For this reason, the range in which the blow-by gas flow is blocked by the lower frame 19 is widened, and the oil accumulated at the lower end of the filter 16 is suppressed from being blown off by the blow-by gas flow.

The oil accumulated in the lower end portion of the filter 16 is discharged from the oil discharge hole 20 through the lowermost end portion of the filter 16, that is, on the bottom wall 11 a of the housing 11. At this time, since a pair of through holes 21 are provided in the lower frame 19 of the filter fixing frame 15, the oil in the filter 16 is removed from the oil by the blow-by gas flow that flows into the filter 16 from the through holes 21. Can lead to. Therefore, the oil accumulated at the lower end of the filter 16 can be quickly discharged from the oil discharge hole 20 into the cylinder head cover C. On the other hand, the blow-by gas that has passed through the filter 16 is exhausted from the outlet 13 with the oil mist removed, and is returned to the intake manifold and burned.
[Summary of effects exhibited by the embodiment]
In the oil mist separator 10 of the present embodiment, the lower frame 19 of the filter fixing frame 15 is formed wider than the upper frame 17 and the side frame 18. For this reason, when the oil droplets are accumulated in the lower part of the filter 16, the blow-by gas flow is blocked by the lower frame 19 of the filter fixing frame 15 and does not hit the lower part of the filter 16. Accordingly, scattering of oil accumulated in the lower portion of the filter 16 is suppressed. Therefore, according to the oil mist separator 10 of the present embodiment, re-scattering of the oil accumulated in the filter 16 can be suppressed, and as a result, the oil mist separation performance can be improved.

  Since the filter fixing frame 15 is provided on the upstream side of the filter 16, the lower part of the filter 16 in which the liquid oil is accumulated is not exposed to the blow-by gas flow by the lower frame 19 of the filter fixing frame 15. Therefore, the re-scattering of the oil accumulated at the lower part of the filter 16 can be further suppressed.

  Since the lower frame 19 of the filter fixing frame 15 is provided with a pair of through holes 21, the oil accumulated in the lower part of the filter 16 can be easily transferred to the oil discharge holes 20 by the blow-by gas flow through the through holes 21. Can be guided to.

  The lower frame 19 of the filter fixing frame 15 is provided at a position where the height of the upper edge corresponds to the height of the lower end of the inlet 12 of the housing 11, so that the blow-by gas to the lower part of the filter 16 by the lower frame 19 The flow shielding effect can be exhibited effectively.

  -Since the oil discharge hole 20 is provided in the portion where the flow of blow-by gas at the downstream lower end position of the filter 16 is stagnant, the oil flowing out from the lower end of the filter 16 is not obstructed by the flow of blow-by gas. The oil can be smoothly guided to the oil discharge hole 20.

  -Since the filter 16 has been subjected to oil repellent processing, it is possible to promote the formation of droplets of oil mist in the filter 16 and to promote the descent of the droplets of oil due to its own weight.

It should be noted that the above embodiment can be modified as follows.
As shown in FIG. 5, the filter fixing frame 15 is disposed on the downstream side of the filter 16, and a through hole 22 is formed through the lower end portion of the lower frame 19, and the bottom of the housing 11 at a position below the through hole 22. The wall 11a may be configured to be provided with the oil discharge hole 20. In this case, the oil in the filter 16 can be guided from the through hole 22 of the lower frame 19 to the oil discharge hole 20 by the blow-by gas flow blown to the lower frame 19.

  As shown in FIG. 6, in the oil mist separator 10 of the above embodiment, the through-hole 21 pierced through the lower frame 19 of the filter fixing frame 15 is omitted, and the oil discharge hole 20 is positioned below the filter 16 ( It can also be provided between the intermediate lower end of the filter 16 and the downstream lower end. In this case, the oil in the filter 16 can be easily discharged from the oil discharge hole 20 directly below. The height of the upper end portion of the lower frame 19 of the filter fixing frame 15 is set at a position lower than the height of the lower end portion of the inlet 12 of the housing 11.

  -In the said embodiment, since the position where the flow of blow-by gas stagnates is on the back extension line of the lower frame 19, it is also possible to expand the downstream edge part of the oil discharge hole 20 further downstream.

  -In the said embodiment, the through-hole 21 provided in the lower frame 19 of the filter fixing frame 15 is made into the long hole extended in a horizontal direction, or the number of holes is increased to three or more, and the function is improved. You can also. Alternatively, the through hole 21 can be omitted.

The shape of the filter fixing frame 15 may be formed in a polygonal shape such as a hexagonal frame shape or an octagonal frame shape.
The oil discharge hole 20 can be positioned between both side frames 18 of the filter fixing frame 15 in the width direction of the bottom wall 11 a of the housing 11. In this case, the oil in the filter 16 can be easily guided to the oil discharge hole 20 by the blow-by gas flow between the both side frames 18.

In the embodiment, the bottom wall 11a of the housing 11 on the downstream side of the filter 16 can be inclined so that the position of the oil discharge hole 20 is the lowest.
The filter fixing frame 15 can be formed integrally with the housing 11 of the oil mist separator 10.

  DESCRIPTION OF SYMBOLS 10 ... Oil mist separator, 11 ... Housing, 11a ... Bottom wall, 12 ... Inlet, 14 ... Blow-by gas flow path, 15 ... Filter fixing frame, 16 ... Filter, 17 ... Upper frame as upper part, 18 ... As side part Side frame, 19 ... lower frame as lower part, 20 ... oil discharge hole, 21, 22 ... through hole, C ... cylinder head cover, d ... width of lower frame, u ... width of upper frame, s ... of side frame width.

Claims (5)

An oil mist separator housing having a blow-by gas flow path is provided on the cylinder head cover of the engine. A filter fixing frame is provided in the housing, and oil mist contained in the blow-by gas is attached to the filter fixing frame. An oil mist separator in which the filter to be converted is fixed so as to cross the blow-by gas flow path,
The lower part of the filter fixing frame is formed wider than the upper part and the side part, and the bottom wall of the housing is provided with an oil discharge hole for discharging oil droplets in the filter ,
The lower part of the filter fixing frame is provided at a position where the height of the upper edge corresponds to the height of the lower end of the inlet for introducing blow-by gas into the housing . The oil mist separator according to claim 1, wherein the filter fixing frame is provided on the upstream side of the filter. The oil mist separator according to claim 2, wherein a through hole is provided in a lower portion of the filter fixing frame. The oil mist separator according to any one of claims 1 to 3 , wherein the oil discharge hole is provided in a portion where a flow of blow-by gas is stagnant at a downstream lower end position of the filter. . The oil mist separator according to any one of claims 1 to 4 , wherein the filter is oil-repellent.

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