JP2011094507A - Oil mist separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil mist separator capable of improving oil mist capturing efficiency, reducing pressure loss of a filter, and improving the service life of the filter by suppressing clogging of the filter. <P>SOLUTION: A housing 12 for separating oil mist 20 from blowby gas containing the oil mist 20 includes an inflow port 13 and an outflow port 14 for the blowby gas, and a gas flow passage 15 formed therein through which the blowby gas flows from the inflow port 13 to the outflow port 14. A first filter 21 on the upstream side and a second filter 23 on the downstream side for separating the oil mist 20 contained in the blowby gas are fixed to cross the gas flow passage 15. A nozzle body 16 as a preliminary separating means for separating the oil mist into a large oil mist 20a having a large particle diameter and a small oil mist 20b having a small particle diameter in advance is provided at the upstream side of the first filter 21. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an oil mist separator for removing oil mist contained in blow-by gas in a blow-by gas flow path by converting it into oil droplets, for example, in a housing provided on a cylinder head cover of an engine.

  When blow-by gas generated during the operation of an automobile engine returns to the intake system while containing oil mist, not only is oil consumed, but the oil mist adheres to intake system components such as the throttle and intake valves. May accumulate and cause malfunctions. Therefore, the oil mist is removed by the oil mist separator, and only the gas component 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, a first filter capable of collecting particulate matter in exhaust gas and applying a voltage is disposed in the housing, and a similar second filter is disposed downstream of the first filter. A diesel particulate filter configured to apply a potential difference having a polarity different from that of the second filter is known (see Patent Document 1). According to the diesel particulate filter, the particulate matter is negatively charged by passing through the first filter, and the particulate matter is collected by the positively charged second filter, thereby improving the collection efficiency. be able to.

JP 2001-182524 A (pages 2 and 4)

  However, in the diesel particulate filter described in Patent Document 1, the particulate material is configured to pass negatively charged by passing through the first filter and then pass through the positively charged second filter. Yes. By the way, the particulate matter that is the material to be filtered is formed by collecting a plurality of particles having different physical properties such as a plurality of particle diameters and a plurality of charges. However, the particulate material described in Patent Document 1 is filtered by the same second filter. For this reason, there has been a problem that the trapping efficiency of the filtration object is gradually lowered, the filter is easily clogged, the life of the filter is shortened, and pressure loss is also generated.

  Accordingly, the object of the present invention is to improve the oil mist capturing efficiency, to suppress clogging of the filter, to reduce pressure loss, and to further extend the life of the filter. The object is to provide an oil mist separator.

  In order to achieve the above object, an oil mist separator according to claim 1 is provided with an inlet and an outlet for an oil mist-containing gas in a housing for separating the oil mist contained in the oil mist-containing gas. A flow path through which the oil mist-containing gas flows from the inlet to the outlet is formed, and a filter that separates the oil mist contained in the oil mist-containing gas is fixed so as to cross the flow path. The upstream side of the filter is provided with pre-separation means for separating the oil mist into a plurality in advance according to the physical properties of the oil mist, and each oil mist pre-separated by the pre-separation means is a filter suitable for each. It is characterized by comprising so that it may capture.

  An oil mist separator according to a second aspect of the present invention is the oil mist separator according to the first aspect, wherein the pre-separating means uses an inertial force of the oil mist to increase the oil mist having a large particle diameter and the oil mist having a small particle diameter. The pre-separated oil mist with a large particle size is captured by a coarse filter, and the pre-separated oil mist with a small particle size is captured by a fine filter. It is characterized by being.

  The filter for an oil mist separator according to a third aspect of the present invention is the oil mist separator according to the first aspect, wherein the pre-separating means applies a positive charge and a negative charge to the oil mist containing carbon and the oil not containing carbon. Oil mist containing pre-separated carbon is captured by a filter that separates carbon, and oil mist that does not contain pre-separated carbon is captured by a filter that separates oil. It is configured.

  The oil mist separator according to a fourth aspect of the present invention is the oil mist separator according to the third aspect, wherein the positive charge is applied to the bottom wall portion of the housing and the negative charge is applied to the upper wall portion of the housing. It is comprised as follows.

  The oil mist separator according to a fifth aspect of the present invention is the oil mist separator according to the first aspect, wherein the preliminary separation means changes the flow rate of the oil mist to change the oil mist having a large particle diameter and the oil mist having a small particle diameter. Pre-separated, configured to capture pre-separated oil mist with large particle size with a coarse filter, and pre-separated oil mist with small particle size with a fine filter. It is characterized by.

According to the present invention, the following effects can be exhibited.
In the oil mist separator of the present invention, pre-separation means for separating the oil mist into a plurality of parts in advance according to the physical properties of the oil mist is provided on the upstream side of the filter. For this reason, each oil mist can be pre-separated by the pre-separating means according to the physical properties such as the particle diameter and electric charge of the oil mist. Thereafter, each pre-separated oil mist can be captured by a filter suitable for each.

  Therefore, according to the present invention, the oil mist capturing efficiency can be improved, the clogging of the filter can be suppressed, the pressure loss can be reduced, and the life of the filter can be extended.

The longitudinal cross-sectional view which shows the oil mist separator in 1st Embodiment. It is sectional drawing in the 2-2 line of FIG. 1, Comprising: The cross-sectional view which shows an oil mist separator. The principal part sectional view showing the oil mist separator of a 2nd embodiment. The principal part sectional view showing the oil mist separator of a 3rd embodiment. The principal part sectional drawing which shows the oil mist separator of another example of this invention. The principal part sectional drawing which shows the oil mist separator of another example of this invention.

(First embodiment)
Hereinafter, a first embodiment of an oil mist separator embodying the present invention will be described in detail with reference to FIGS. 1 and 2.

  As shown in FIGS. 1 and 2, an oil mist separator 11 that recovers oil from oil mist in blow-by gas is provided on a cylinder head cover 10 provided in a cylinder block of the engine. The housing 12 of the oil mist separator 11 is formed in a square cylinder shape, and an inlet 13 for introducing blowby gas is provided on the bottom wall 12a, and an outlet 14 for exhausting blowby gas is provided on the upper wall 12b. Is provided. A gas flow path 15 through which blow-by gas flows from the inflow port 13 toward the outflow port 14 is formed in the housing 12 by using the intake pressure of the engine, as indicated by an arrow in the figure. The bottom wall 12 a of the housing 12 is formed integrally with the cylinder head cover 10.

  Between the inflow port 13 and the outflow port 14 in the housing 12, a substantially tapered nozzle body 16 constituting a pre-separation means is disposed. The tapered wall 17 constituting the nozzle body 16 is reduced in diameter toward the front in the direction of the gas flow path 15. A partition wall 19 is supported at the position of the downstream end of the nozzle body 16 so as to be orthogonal to the gas flow path 15 between the upper wall 12b and the bottom wall 12a. A number of through holes 18 are formed at the downstream end of the nozzle body 16. The nozzle body 16 collects the gas flow including the oil mist 20 at the center of the gas flow path 15 to increase the flow velocity, and the flow velocity is further increased by passing through the through hole 18.

  A first filter 21 made of a non-woven fabric for colliding and capturing oil mist 20a having a large particle diameter is disposed at a downstream position of the nozzle body 16 so as to face a portion where the through hole 18 of the nozzle body 16 is formed. ing. As will be described later, the oil mist 20a having a large particle diameter that has passed through the through hole 18 collides with the first filter 21 by its inertial force and is captured. Between the outer periphery of the first filter 21 and the upper wall 12b and the bottom wall 12a of the housing 12, there is a passage 22 through which a gas flow including an oil mist 20b having a small particle diameter that is not captured by the first filter 21 passes. Is formed.

  A second filter 23 for capturing oil mist 20b having a small particle diameter is disposed at a downstream position of the first filter 21 so as to cross the entire gas flow path 15 between the upper wall 12b and the bottom wall 12a. ing. The oil mist 20 b having a small particle diameter that passes through the through hole 18 and reaches the second filter 23 through the flow passage 22 around the first filter 21 is captured by the second filter 23. Has been. A circular oil discharge hole 24 is formed through the bottom wall 12 a downstream of the second filter 23.

Next, the operation of the oil mist separator 11 configured as described above will be described.
Now, blow-by gas introduced into the housing 12 from the inlet 13 of the housing 12 by the intake air pressure of the engine flows downstream along the gas flow path 15 and reaches the nozzle body 16. In the nozzle body 16, both the oil mist 20 a having a large particle diameter and the oil mist 20 b having a small particle diameter are collected together by the taper wall 17 to the center of the gas flow, and penetrate the partition wall 19 in a state where the flow velocity is increased. Pass through hole 18. At this time, since the oil mist 20a having a large particle diameter has a large inertial force, the oil mist 20a travels linearly along the direction of the gas flow path 15 and collides with the first filter 21 in front thereof. Since the first filter 21 is composed of a coarse filter, the oil mist 20a having a large particle diameter adheres to and is captured by the first filter 21 without causing the first filter 21 to be clogged. Oil droplets.

  On the other hand, since the oil mist 20b having a small particle diameter has a small inertial force, the oil mist 20b passes through the through hole 18 of the partition wall 19 and then diffuses up and down along the gas flow and passes through the upper and lower passages 22 of the first filter 21. To the second filter 23 located downstream thereof. Since the second filter 23 is composed of a fine filter, the oil mist 20b having a small particle diameter adheres to and is captured by the second filter 23 and is converted into oil droplets there.

  The oil droplets thus fall down along the fiber surfaces of the first filter 21 and the second filter 23 due to their own weight, and the bottom wall of the housing 12 from the lower ends of the first filter 21 and the second filter 23. Accumulate on 12a. The oil accumulated on the bottom wall 12 a is caused to flow downstream by the wind pressure of the blow-by gas and is discharged from the oil discharge hole 24. On the other hand, the blow-by gas that has passed through the second filter 23 is exhausted from the outlet 14 with the oil mist 20 removed, and is returned to the intake manifold and burned.

The effects exhibited by the above first embodiment will be collectively described below.
(1) According to the oil mist separator 11 of the first embodiment, the upstream side of the first filter 21 is a pre-separation unit that separates the oil mist 20 into two according to the physical properties of the oil mist 20 in advance. A nozzle body 16 and a through hole 18 are provided. For this reason, the oil mist 20 having different particle diameters can be preliminarily separated by the nozzle body 16 and the through hole 18, and then the oil mist 20 separated in advance can be captured by a filter suitable for each.

  That is, the nozzle body 16 and the through-hole 18 can separate the oil mist 20a having a large particle diameter and the oil mist 20b having a small particle diameter in advance using a difference in inertia force of the oil mist 20. The pre-separated oil mist 20a having a large particle size is captured by the first filter 21 having a coarse filter and less likely to be clogged, and the pre-separated oil mist 20b having a small particle size has a high fine mesh capturing ability. Captured by the second filter 23.

  Therefore, since the oil mist 20 can be captured by a filter suitable for it, the capture efficiency of the oil mist 20 can be improved, clogging can be suppressed, and the pressure loss of the first filter 21 and the second filter 23 can be reduced. In addition, the lifetime of the first filter 21 and the second filter 23 can be extended.

(2) Since the pressure loss of the first filter 21 and the second filter 23 can be reduced, the pressure increase in the crank chamber of the engine can be prevented, and the cause of the engine failure can be avoided in advance.
(Second Embodiment)
Next, a second embodiment of the oil mist separator 11 embodying the present invention will be described with reference to FIG.

  As shown in FIG. 3, the lower end of the partition wall 19 of the nozzle body 16 is connected to the positive electrode 25, the lower part of the partition wall 19 is positively charged, and the upper end is connected to the negative electrode 26. The upper part of the partition wall 19 is negatively charged. Accordingly, the oil mist 20c containing negatively charged carbon is attracted to the lower part of the partition wall 19 and passes through the lower through hole 18, while the positively charged oil mist 20d containing no carbon is placed on the upper part of the partition wall 19. It is configured to be pre-separated by being attracted.

  At the downstream position of the partition wall 19, a third filter 27 for separating the oil mist 20 c containing carbon is erected on the lower half of the gas flow path 15 on the bottom wall 12 a of the housing 12. The third filter 27 is formed of, for example, an oil-repellent fluorine fiber that can easily separate the oil mist 20c containing carbon. An upper passage 28 through which oil mist 20d not containing carbon passes is formed between the upper end portion of the third filter 27 and the upper wall 12b of the housing 12. Further, a fourth filter 29 for separating oil is disposed between the upper wall 12 b and the bottom wall 12 a of the housing 12 at a position downstream of the third filter 27 so as to block the gas flow path 15. The fourth filter 29 is formed of, for example, lipophilic polypropylene fiber that easily separates oil. The pre-separating means is constituted by a partition wall 19 and the like charged by the positive electrode 25 and the negative electrode 26.

  Now, of the oil mist 20 introduced into the housing 12 through the inlet 13 of the housing 12 and reaching the nozzle body 16, the oil mist 20 c that contains carbon and is negatively charged is charged into the positively charged partition wall 19. It is attracted to the lower part and passes through the lower through hole 18. On the other hand, the positively charged oil mist 20 d not containing carbon is attracted to the upper part of the negatively charged partition wall 19 and passes through the upper through hole 18.

  The oil mist 20 c containing carbon that has passed through the lower through-hole 18 collides with the third filter 27 located on the downstream side of the partition wall 19. Since the third filter 27 is a filter suitable for separating carbon, the oil mist 20c containing carbon colliding with the third filter 27 is easily attached to and captured by the third filter 27 to form oil droplets. Is done. On the other hand, the oil mist 20 d containing almost no carbon that has passed through the through-hole 18 above the partition wall 19 passes through the upper passage 28 and hits the fourth filter 29 with almost no collision with the third filter 27. Since the fourth filter 29 is a filter suitable for separating carbonless oil, the oil mist 20d not containing carbon hitting the fourth filter 29 is easily attached to and captured by the fourth filter 29, Oil droplets.

  (3) Therefore, according to the second embodiment, positive voltage and negative voltage are applied to the partition wall 19 constituting the pre-separation means, and the oil mist 20c containing carbon and the oil mist 20d not containing carbon are preliminarily applied. It comes to separate. For this reason, the oil mist 20c containing carbon separated in advance is separated by the third filter 27 that separates carbon, and the oil mist 20d not containing carbon separated in advance is separated by the fourth filter 29 that separates oil. . Therefore, the oil mist 20 can be separated in advance based on the presence or absence of carbon in the oil mist 20, and the obtained oil mist 20 can be effectively separated by the third filter 27 and the fourth filter 29 suitable for each.

  (4) In this case, in the partition wall 19, the positive charge is charged on the bottom wall 12 a side of the housing 12, and the negative charge is charged on the top wall 12 b side of the housing 12. The oil mist 20c containing carbon can be easily dropped downward using the negative charge, and the oil mist 20 can be more effectively separated.

(5) Therefore, it is possible to prevent carbon from being introduced into the intake system of the engine, and to avoid inconvenient situations such as carbon adhesion to the engine valve.
(Third embodiment)
Next, a third embodiment of the oil mist separator 11 embodying the present invention will be described with reference to FIG.

  As shown in FIG. 4, the housing main body 12 </ b> A is configured by an upstream cylindrical body 12 </ b> B having a narrow upstream side, and is configured such that the upstream lower side wall 12 d is positioned downstream of the upstream upper side wall 12 e. Has been. Furthermore, the downstream side from the center of the downstream side wall 12f is constituted by a narrow downstream side cylinder 12C. A shielding plate 30 is supported on the downstream side of the upstream cylinder 12B so as to be formed in a U-shape and to face the gas flow path 15 in the upstream cylinder 12B.

  The cross-sectional area of the lower passage 31 between the lower portion of the shielding plate 30 and the upstream lower side wall 12d of the housing body 12A is the upper passage between the upper portion of the shielding plate 30 and the upstream upper side wall 12e of the housing body 12A. It is set to be smaller than the cross-sectional area of 32. Accordingly, the flow velocity of the gas flow through the lower passage 31 is configured to be higher than the flow velocity of the gas flow through the upper passage 32, and the oil mist 20 a having a large particle diameter flows through the lower passage 31. An oil mist 20b having a small particle diameter flows. The ratio of the flow rate of the gas flow in the lower passage 31 and the flow velocity of the gas flow in the upper passage 32, that is, the ratio of the cross-sectional area of the lower passage 31 to the cross-sectional area of the upper passage 32 is as follows. The oil mist 20b having a small diameter is set so as to be satisfactorily separated. The pre-separating means includes the shielding plate 30, the lower passage 31, the upper passage 32, and the like.

  On the downstream side of the shielding plate 30, a partition wall 33 extending from the vertical center position of the downstream side surface of the shielding plate 30 toward the center of the downstream cylindrical body 12 </ b> C is provided. A rough first filter 21 whose downstream side is in close contact with the downstream lower side wall 12g of the housing body 12A is disposed on the lower surface of the partition wall 33. On the upper surface of the partition wall 33, the downstream side is downstream of the housing body 12A. A second filter 23 having a fine filter is provided in close contact with the upper side wall 12h. Accordingly, the oil mist 20a having a large particle diameter is captured by the first filter 21 and the oil mist 20b having a small particle diameter is captured by the second filter 23. In the third embodiment, the same inlet 13, outlet 14, and oil discharge hole 24 as those in the first embodiment are provided.

  Now, the oil mist 20a having a large particle diameter in the oil mist 20 flowing in the upstream cylinder 12B is guided to the lower passage 31, passes through the lower passage 31 at a high speed, and reaches the first filter 21. The Since the first filter 21 is formed of a coarse filter, the oil mist 20a having a large particle diameter is well attached and captured. On the other hand, the light oil mist 20 b having a small particle diameter is guided to the upper passage 32, passes through the upper passage 32 at a low speed, and reaches the second filter 23. Since the second filter 23 is composed of a fine filter, the oil mist 20b having a small particle diameter is well attached and captured.

  (6) According to the third embodiment, the lower passage 31 and the upper passage 32 constituting the pre-separation means change the flow velocity of the oil mist 20, the particle diameter is large, the heavy oil mist 20a, and the particle diameter A small and light oil mist 20b can be separated in advance. For this reason, the oil mist 20a having a large particle diameter separated in advance is captured by the first filter 21 having a coarse filter, and the oil mist 20b having a small particle diameter separated in advance is captured by the second filter 23 having a fine filter. The Therefore, the oil mist 20 having different particle diameters can be separated in advance based on the change in flow velocity, and the obtained oil mist 20 can be effectively separated by a filter suitable for each.

It should be noted that the above embodiment can be modified as follows.
As shown in FIG. 5, the pre-separation means is formed in a partition plate 34 provided so as to cross the gas flow path 15 between the upper wall 12 b and the bottom wall 12 a of the housing 12, and in the lower part of the partition plate 34. The plurality of through holes 18, the partition plate 35 extending from the downstream side surface of the partition plate 34 to the downstream side, and the insertion holes 36 formed through the partition plate 35 can be formed. A first filter 21 having a coarse filter is disposed in the lower passage 37 between the partition plate 35 and the bottom wall 12a, and a filter mesh is provided in the upper passage 38 between the partition plate 35 and the upper wall 12b. A fine second filter 23 is provided.

  The oil mist 20a having a large particle diameter that has passed through the through hole 18 of the partition plate 34 collides with the first filter 21 of the lower passage 37 due to its inertial force, and is attached and separated, and the through hole of the partition plate 34 The oil mist 20 b having a small particle diameter that has passed through 18 enters the upper passage 38 through the insertion hole 36 of the partition plate 35, and adheres to and is separated from the second filter 23.

  As shown in FIG. 6, the nozzle body 16 constituting the pre-separation means has a horizontal trapezoidal cross section on the downstream side, and a plurality of through holes 18 are formed in the downstream side wall 39. On the downstream side of the nozzle body 16, a collection cylinder 41 having an inverted L-shaped cross section having a cylinder portion 40 opened so as to face the downstream side wall 39 of the nozzle body 16 penetrates the bottom wall 12 a of the housing 12. Is provided. A first filter 21 having a coarse filter is disposed in the cylindrical portion 40. A passage 22 is formed in the outer peripheral portion of the collection cylinder 41. Further, a second filter 23 having a fine filter is disposed at a downstream position of the collection cylinder 41.

  Then, the oil mist 20a having a large particle diameter that has passed through the through hole 18 in the downstream side wall 39 enters into the cylinder portion 40 of the collection cylinder 41 due to its inertial force, collides with the first filter 21, and is attached and captured. . On the other hand, the oil mist 20b having a small particle diameter that has passed through the through hole 18 in the downstream side wall 39 hits the second filter 23 through the passage 22 on the outer periphery of the cylindrical portion 40 of the collecting cylinder 41, and is attached and captured there.

  A combination of the form using the inertial force of the first embodiment and the form using the charge of the second embodiment as the pre-separation means, for example, an oil mist 20a having a large particle diameter and an oil mist 20c containing carbon The oil mist 20b having a small particle diameter and the oil mist 20d not containing carbon can be separated in advance.

  A combination of the form using the charge of the second embodiment and the form using the flow velocity of the third embodiment as the pre-separation means, for example, an oil mist 20a having a large particle diameter and an oil mist 20c containing carbon; The oil mist 20b having a small particle diameter and the oil mist 20d not containing carbon may be separated in advance.

  In the second embodiment, the nozzle body 16 is eliminated, and a positively charged baffle plate is erected at the bottom of the housing 12, or a plurality of baffle plates are formed so that the gas flow meanders between the baffle plates. It is also possible to provide a positively charged charging area on the bottom wall 12a.

  In the first and second embodiments, the through hole 18 may be eliminated, and the downstream end of the nozzle body 16 may be fully opened. Even in this case, the gas flow can be increased by the nozzle body 16.

  -The fourth filter 29 may be made of an oil-repellent material.

  DESCRIPTION OF SYMBOLS 11 ... Oil mist separator, 12 ... Housing, 12a ... Bottom wall, 12b ... Upper wall, 13 ... Inlet, 14 ... Outlet, 15 ... Gas flow path, 16 ... Nozzle body as pre-separation means, 20 ... Oil mist 20a ... Oil mist with a large particle size, 20b ... Oil mist with a small particle size, 20c ... Oil mist with carbon, 20d ... Oil mist without carbon, 21 ... First filter for separating oil mist with large particle size , 23 ... a second filter for separating oil mist having a small particle diameter, 27 ... a third filter for separating oil mist containing carbon, 29 ... a fourth filter for separating oil mist not containing carbon.

Claims (5)

A housing for separating oil mist contained in the oil mist-containing gas is provided with an inlet and an outlet for the oil mist-containing gas to form a flow path for the oil mist-containing gas to flow from the inlet to the outlet. An oil mist separator in which a filter for separating oil mist contained in the contained gas is fixed so as to cross the flow path,
The upstream side of the filter is provided with pre-separation means for separating oil mist into a plurality of parts in advance according to the physical properties of the oil mist, and each oil mist pre-separated by the pre-separation means is captured by a filter suitable for each. An oil mist separator configured as described above. The pre-separating means pre-separates the oil mist having a large particle diameter and the oil mist having a small particle diameter using the inertial force of the oil mist. 2. The oil mist separator according to claim 1, wherein the oil mist having a small particle diameter is captured by a coarse filter, and is captured by a fine filter. The pre-separation means applies a positive charge and a negative charge to pre-separate an oil mist containing carbon and an oil mist not containing carbon, and the oil mist containing pre-separated carbon separates the carbon. The oil mist separator according to claim 1, wherein the oil mist which is captured by a filter and does not contain carbon separated in advance is captured by a filter which separates oil. 4. The oil mist separator according to claim 3, wherein the positive charge is applied to a bottom wall side portion of the housing, and the negative charge is applied to a top wall side portion of the housing. The pre-separating means is configured to pre-separate the oil mist having a large particle diameter and the oil mist having a small particle diameter by changing the flow rate of the oil mist. The oil mist separator according to claim 1, wherein the oil mist having a small particle diameter, which is captured by a coarse filter, is captured by a fine filter.

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