JP2013151905A - Oil separator of blowby gas processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively discharge oil separated in an oil separating chamber from an oil discharging channel opening in the exterior wall face of sidewall of a cylinder block.SOLUTION: An oil separator 40 has an oil separating chamber 41 arranged in the mid of a blowby gas channel 31 and facing the exterior wall face 43 of a sidewall 42 of a cylinder block 12 and separating oil O from a blowby gas G, an oil returning channel (lower longitudinal hole part 54) extending in a substantially vertical direction in the sidewall 42, and an oil discharging channel 55 opening in a position spaced apart upward from the bottom part 47 of the oil separating chamber 41 in the exterior wall face 43 and connecting to a lower longitudinal hole part 54. Inclining parts 57, 58 inclining so as to heighten as backing away from the oil discharging channel 55 and an oil storing part 60 adjacent to the lowermost part of the inclining parts 57, 58 and positioned in a lower position than lowermost part are formed in the bottom part 47. The oil discharging channel 55 is opened in a position spaced apart upward from the bottom part of the oil storing part 60.

Description

  The present invention relates to an oil separator that is provided in a blow-by gas processing apparatus that processes blow-by gas leaked from a combustion chamber into a crank chamber by returning it to an intake passage, and separates and recovers oil contained in the blow-by gas.

  In an internal combustion engine mounted on a vehicle such as an automobile, blow-by gas (unburned mixture or combustion gas) leaks from a combustion chamber into a crank chamber through a gap between a piston and a cylinder during operation. Therefore, the internal combustion engine is provided with a blow-by gas processing device that returns the blow-by gas from the crank chamber to the intake passage through the blow-by gas passage and re-combusts it in the combustion chamber.

  However, when the blow-by gas passes through the crank chamber, the oil of the internal combustion engine becomes mist and is mixed into the blow-by gas. When the blow-by gas containing the mist-like oil (oil mist) is reburned, the oil consumption increases. Therefore, in order to prevent the oil contained in the blow-by gas from being taken away by the flow of the blow-by gas to the intake passage or the like, the oil is separated from the blow-by gas, as described in Patent Document 1, for example. An oil separator that returns oil to the crank chamber through the oil return passage is provided in the blow-by gas processing apparatus.

  The oil separation chamber constituting the main part of the oil separator is provided in the middle of the blow-by gas passage and facing the outer wall surface of the side wall portion of the cylinder block. The upstream portion of the blow-by gas passage from the oil separation chamber extends substantially vertically in the side wall and is opened at the bottom of the oil separation chamber. In Patent Document 1, the upstream portion of the blow-by gas passage also serves as an oil return passage.

  According to the blow-by gas processing apparatus, the blow-by gas in the crank chamber passes through the oil separation chamber while being returned to the intake passage through the blow-by gas passage. In the process of passing, the mist-like oil contained in the blow-by gas is liquefied through contact with the inner wall surface of the oil separation chamber and separated from the blow-by gas. The separated oil drops or flows down to the bottom of the oil separation chamber, and then returns to the crank chamber through the oil return passage.

  On the other hand, in an internal combustion engine, an oil passage for returning oil from a cylinder head to a crank chamber is generally provided in the cylinder block. For example, in Patent Document 2, a horizontal hole portion (meat stealing hole) extending in a substantially horizontal direction from the outer wall surface of the side wall portion of the cylinder block, and a lower hole extending from the upper surface of the cylinder block to be connected to the horizontal hole portion (meat stealing hole). A vertical hole portion (oil return hole portion) and a lower vertical hole portion (oil return hole portion) extending upward from the lower surface of the cylinder block and connected to the horizontal hole portion (meat stealing hole) are provided. In Patent Document 2, the upper and lower vertical hole portions (oil return hole portions) are formed by casting, and the horizontal hole portion (meat stealing hole) causes these vertical hole portions (oil return hole portions) to communicate with each other. Play a role. The phrase in parentheses following the member name indicates the member name used in Patent Document 2.

  By the way, the oil passage is also a passage for returning oil to the crank chamber, like the oil return passage. Therefore, it can be considered that the oil passage is used as an oil return passage, that is, the oil passage also serves as the oil return passage. By doing so, it is possible to reduce the number of passages for returning the oil to the crank chamber.

  However, in this case, it is necessary to provide a passage (oil discharge passage) for communicating the oil passage and the oil separation chamber. This oil discharge passage takes either a form extending in a substantially vertical direction or a form extending in a substantially horizontal direction.

JP 2008-57501 A JP 2005-16418 A

  However, when the oil discharge passage is opened by drilling, as described in Patent Document 2 (FIG. 1, FIG. 3, etc.), the periphery of the side hole portion (the meat stealing hole) is the outer wall surface of the side wall portion. When projecting, the projecting portion may interfere with the drilling blade. Specifically, this interference can occur when a cutting tool is used to open an oil discharge passage that opens to the bottom of the oil separation chamber and extends substantially downward. Therefore, an oil discharge passage extending in a substantially horizontal direction is opened in the side wall portion.

  On the other hand, when an oil discharge passage extending in a substantially horizontal direction is opened in the side wall, the oil discharge passage needs to be separated from the bottom of the oil separation chamber upward by a certain distance or more. This is to prevent the blade tool from coming into contact with the bottom and to prevent the force from being biased against the blade tool. As described above, since the formation position of the oil discharge passage is limited, it is difficult to form the oil discharge passage in contact with the bottom of the oil separation chamber. In this case, although once collected at the bottom of the oil separation chamber, the oil below the oil discharge passage is not discharged and remains in the oil separation chamber. This oil generates sludge by reacting with exhaust components (NOx, etc.) in blow-by gas.

  In particular, when the bottom of the oil separator is formed horizontally as in Patent Document 1, the amount of oil remaining in the oil separation chamber without being discharged from the oil discharge passage is large. Also, oil remains over a wide area at the bottom. The area (surface area) of the oil that comes into contact with the exhaust components (NOx, etc.) in the blow-by gas is large, and the amount of sludge generated when the oil reacts with the exhaust components and the like increases.

  These problems are not limited to those described above, and the oil return passage extends substantially vertically in the side wall portion of the cylinder block. Due to various restrictions, the oil discharge passage is separated from the oil on the outer wall surface of the side wall portion of the cylinder block. This is common to the oil separator that is opened at a location spaced upward from the bottom of the chamber and connected to the oil return passage.

  The present invention has been made in view of such circumstances, and an object of the present invention is to efficiently discharge the oil separated in the oil separation chamber from an oil discharge passage that opens on the outer wall surface of the side wall portion of the cylinder block. Another object of the present invention is to provide an oil separator for a blow-by gas processing apparatus.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 is provided in a blow-by gas processing device that processes blow-by gas leaked from the combustion chamber of the internal combustion engine into the crank chamber and returns the air to the intake passage through the blow-by gas passage. An oil separation chamber that is provided in the middle and faces the outer wall surface of the side wall portion of the cylinder block, separates oil from the blow-by gas, an oil return passage that extends substantially vertically in the side wall portion, and the side wall portion An oil separator of a blow-by gas treatment device comprising an oil discharge passage that opens at a location spaced upward from the bottom of the oil separation chamber on the outer wall surface of the outer wall surface and is connected to the oil return passage, the bottom of the oil separation chamber In the inclined portion that inclines so as to become farther away from the oil discharge passage, and the lowermost portion of the inclined portion. An oil reservoir portion that is in contact with and located lower than the lowermost portion, and the oil discharge passage is opened at a location spaced upward from the bottom of the oil reservoir portion. To do.

  According to the above configuration, the blow-by gas generated by the operation of the internal combustion engine flows into the oil separation chamber of the oil separator in the process of flowing through the blow-by gas passage. In the oil separation chamber, the mist-like oil contained in the blow-by gas is liquefied and separated from the blow-by gas. The separated oil drops or flows down to the bottom of the oil separation chamber, then flows along the inclined portion to the low side, and flows into the oil reservoir. Of the oil, the oil located higher than the lowest part of the oil discharge passage is discharged from the oil separation chamber through the oil discharge passage. The discharged oil flows down in the oil return passage and is returned to the crank chamber.

  Here, in order to prevent perforation of the drilling blade, the oil discharge passage must be opened at a position spaced apart from the bottom of the oil separation chamber by a certain distance or more (high position) Even if there is a restriction on (s), in the invention according to claim 1, the oil discharge passage can be opened at a lower position.

  That is, by providing the bottom of the oil separation chamber with an inclined portion that becomes higher as the distance from the oil discharge passage increases, the lower portion of the oil discharge passage at the bottom becomes lower. The oil discharge passage can be opened at a lower position than the case where the inclined portion and the oil reservoir portion are not provided because the lower portion of the bottom portion is lower.

  In addition, an oil reservoir that is located lower than the lowermost portion is provided at a location adjacent to the lowermost portion of the inclined portion, so that the oil reservoir is provided below the oil discharge passage at the bottom of the oil separation chamber. The part which becomes becomes lower. The oil discharge passage can be opened at a lower position than the case where the inclined portion is provided but the oil reservoir portion is not provided because the lower portion of the bottom portion is lower.

  As a result, by opening the oil discharge passage at a lower location, the amount of oil discharged from the oil discharge passage increases (the amount of oil remaining in the oil separation chamber without being discharged decreases).

  According to a second aspect of the present invention, in the first aspect of the present invention, the bottom of the oil reservoir is a sub-inclined portion that is the lowest below the oil discharge passage and becomes higher as the distance from the oil discharge passage increases. The gist is that is formed.

  According to the above configuration, the bottom portion of the oil sump portion is formed with the sub-inclined portion that is lowest below the oil discharge passage and becomes higher as the distance from the oil discharge passage increases. The lower part becomes lower. The oil discharge passage can be opened at a lower position than in the case where the bottom portion of the oil reservoir portion is not inclined by the amount of the lower portion of the bottom portion.

  As a result, the amount of oil discharged from the oil discharge passage is further increased by opening the oil discharge passage at a lower position than when the sub-inclined portion is not formed (when the bottom portion is not inclined). Less oil remains in the oil separation chamber).

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the side wall portion is provided with an oil passage for returning the oil of the cylinder head to the crank chamber extending in a substantially vertical direction. The gist of the invention is that the oil return passage is constituted by at least a part of the oil passage, and the oil discharge passage is connected to the oil passage.

  According to said structure, at least one part of the oil path provided in order to return the oil of a cylinder head to a crank chamber functions also as an oil return path for returning the oil isolate | separated from blow-by gas to a crank chamber. . Therefore, the number of passages for returning oil to the crank chamber can be reduced as compared with the case where the oil return passage is provided separately from the oil passage.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a connection portion of the blow-by gas passage with the oil separation chamber upstream of the oil separation chamber is The gist of the invention is that the blow-by gas inlet to the oil separation chamber is opened above the oil discharge passage.

  The blow-by gas passage that is connected to the oil separation chamber through the gas inlet and the oil discharge passage that is open in the outer wall surface of the side wall portion and is connected to the oil separation chamber can pass the blow-by gas. The oil can pass through.

  In this respect, in the oil separation chamber, the gas inlet of the blow-by gas passage opens above the oil discharge passage. In the invention according to claim 4, the oil is separated from the blow-by gas and drops or flows down to the bottom of the oil separation chamber. The oil thus easily discharged from the oil discharge passage opened at a position lower than the gas inlet and hardly flows into the gas inlet. Therefore, the flow of blow-by gas in the blow-by gas passage is difficult to be hindered by oil. Along with this, the flow amount of blow-by gas in the oil discharge passage is reduced, and the oil discharge from the oil discharge passage is hardly hindered by the blow-by gas.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, a portion of the blow-by gas passage upstream of the oil separation chamber has a larger flow path than the oil discharge passage. The gist is that the gas passage has an area.

  Of the blow-by gas passages, the blow-by gas can be passed through the gas passage connected to the oil separation chamber and the oil discharge passage connected to the oil separation chamber, and the oil can be passed through after separation. .

  In this respect, in the invention according to claim 5, wherein the gas passage has a larger flow area than the oil discharge passage, the gas passage has a smaller flow resistance to the blow-by gas than the oil discharge passage, and the blow-by gas Is easier to flow through the gas passage than the oil discharge passage. As a result, the flow amount of blow-by gas in the oil discharge passage is reduced, and the oil discharge from the oil discharge passage is hardly hindered by the blow-by gas.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows one Embodiment which actualized this invention, and is sectional drawing which shows typically the internal structure of the engine provided with the blow-by gas processing apparatus. It is a figure showing one embodiment, and a partial side view of a cylinder block provided with an oil separator. The fragmentary sectional view which expands and shows the X section in FIG. The partial side view which expands and shows the Y section in FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a vehicle is equipped with a gasoline engine (hereinafter simply referred to as an engine) 11 as an internal combustion engine. The engine 11 includes a cylinder block 12, a cylinder head 13 and a head cover 14 that are sequentially attached to the upper side thereof, and a crankcase 15 and an oil pan 16 that are sequentially attached to the lower side of the cylinder block 12. In the engine 11, air is sucked into the combustion chamber 18 for each cylinder (cylinder 17) through the intake passage 19 and fuel is injected and supplied from the fuel injection valve 21. When the fuel / air mixture is ignited by the spark plug 22, the mixture burns, the pistons 23 reciprocate in the cylinders 17, and the crankshaft 24 that is the output shaft of the engine 11 rotates. To do. Exhaust gas generated by the combustion of the air-fuel mixture is discharged from each combustion chamber 18 to the exhaust passage 25.

  The output adjustment of the engine 11 is realized by adjusting the opening degree (throttle opening degree) of the throttle valve 26 provided in the intake passage 19. That is, the amount of air sucked into the combustion chamber 18 is changed by adjusting the throttle opening, and the fuel injection amount from the fuel injection valve 21 is controlled in accordance with the change, and the mixture charged into the combustion chamber 18 is mixed. The amount of energy changes and the output of the engine 11 is adjusted.

  In the engine 11, in the compression stroke and the expansion stroke, more precisely, a crank chamber is formed between the cylinder 17 and the piston 23, more precisely, a gap between the piston ring (not shown) and the cylinder 17, and a gap between the piston ring and the piston 23. Gas leaks to 27. The crank chamber 27 is a space in which the crankshaft 24 is accommodated. Specifically, the crank chamber 27 is a space surrounded by the cylinder block 12, the crankcase 15, and the oil pan 16. The gas includes an air-fuel mixture that leaks in the compression stroke, a combustion gas that leaks in the expansion stroke, and the like, and is called blow-by gas G. The blow-by gas G can cause engine oil (hereinafter simply referred to as “oil”) to deteriorate or rust inside the engine 11.

  Therefore, the engine 11 is provided with a blow-by gas processing device 30 that returns the blow-by gas G to the intake passage 19 and re-combusts it in the combustion chamber 18. The blow-by gas processing device 30 includes a blow-by gas passage 31 that connects the crank chamber 27 and a downstream of the throttle valve 26 in the intake passage 19, for example, a surge tank 28. In the blowby gas processing device 30, a negative pressure (a pressure lower than the atmospheric pressure, hereinafter referred to as “intake negative pressure”) generated downstream of the throttle valve 26 acts on the crank chamber 27 through the blowby gas passage 31. The blow-by gas G leaked from the combustion chamber 18 is sucked into the crank chamber 27 by the intake negative pressure. A PCV valve 36 is provided in the middle of the blowby gas passage 31 as an adjustment valve for adjusting the amount of blowby gas G flowing through the blowby gas passage 31 according to the operating state of the engine 11.

  Further, the blow-by gas processing device 30 includes an outside air introduction passage 37 for introducing air (outside air) outside the engine 11 into the crank chamber 27 in order to reduce the concentration of the blow-by gas G in the crank chamber 27. . A part of the outside air introduction passage 37 is constituted by a tube 38 that connects a portion of the intake passage 19 upstream of the throttle valve 26 and the head cover 14. A part of the outside air introduction passage 37 is provided in the head cover 14, the cylinder head 13, the cylinder block 12, and the like. Then, due to the intake negative pressure, outside air is sucked into the crank chamber 27 through the outside air introduction passage 37.

  In this way, the blow-by gas G that is generated by the operation of the engine 11 and leaks from the combustion chamber 18 and the outside air introduced to reduce the concentration of the blow-by gas G flow into the crank chamber 27. The mixture of the blowby gas G and the outside air is sucked into the intake passage 19 from the crank chamber 27 through the blowby gas passage 31 by the intake negative pressure.

  By the way, when the air-fuel mixture passes through the crank chamber 27 and the like, the oil becomes mist (oil mist) and is mixed into the air-fuel mixture. When the air-fuel mixture containing the mist-like oil is reburned, the oil consumption increases. Therefore, the oil separator 40 is provided to separate and collect the mist-like oil from the mixture of the blow-by gas G and the outside air, thereby preventing the oil from being taken away to the intake passage 19 and the like along the flow of the blow-by gas G. Like to do.

As shown in FIGS. 2 and 3, the oil separator 40 includes an oil separation chamber 41, an oil return passage, and an oil discharge passage 55.
The oil separation chamber 41 is a chamber for separating oil from the blow-by gas G, and is provided in the middle of the blow-by gas passage 31 and facing the outer wall surface 43 of the side wall portion 42 in the cylinder block 12. More specifically, an annular protrusion 44 having an annular shape is integrally formed on the outer wall surface 43. A plate-like cover 45 is fastened and fixed to the annular protrusion 44 by a fastening member such as a bolt 46. In FIG. 2, the cover 45 is indicated by a two-dot chain line. A space surrounded by the outer wall surface 43, the annular protrusion 44 and the cover 45 is an oil separation chamber 41. The blow-by gas G is sealed between the annular protrusion 44 and the cover 45 so as not to leak out of the oil separation chamber 41.

  The upstream portion of the blow-by gas passage 31 with respect to the oil separation chamber 41 is composed of a pair of gas passages 32 and 33 each having a circular cross section and extending in the vertical direction. The gas passages 32 and 33 are formed so that the inner diameter is the same at any position in the length direction of the gas passages 32 and 33. The lower end portions of the gas passages 32 and 33 are connected to locations separated from each other in the crank chamber 27 in the arrangement direction of the cylinders (cylinder 17) (left and right direction in FIG. 2). The upper ends of the gas passages 32 and 33 are opened above the bottom 47 of the oil separation chamber 41, and these openings open the gas inlets 32 </ b> A and 33 </ b> A of the blow-by gas G to the oil separation chamber 41. It is composed.

  A portion of the blow-by gas passage 31 downstream of the oil separation chamber 41 is constituted by one gas passage 34 (see FIG. 3). A connection portion of the gas passage 34 with the oil separation chamber 41 is a gas outlet 34A for blow-by gas G from which the oil O is separated in the oil separation chamber 41. The gas outlet 34A is provided in the oil separation chamber 41 at a location far away from the gas inlets 32A and 33A, for example, at the top of the oil separation chamber 41.

  Here, an oil passage for returning the oil O from the cylinder head 13 to the crank chamber 27 is provided in the side wall portion 42 of the cylinder block 12. This oil passage has the same configuration as that of Patent Document 2 described above. That is, the oil passage includes a horizontal hole portion 52 extending in a substantially horizontal direction from the outer wall surface 43 of the side wall portion 42, and an upper vertical portion extending substantially downward in the side wall portion 42 from the upper surface of the cylinder block 12 and connected to the horizontal hole portion 52 from above. The hole 53 includes a lower vertical hole 54 that extends substantially upward in the side wall 42 from the lower surface of the cylinder block 12 and is connected to the horizontal hole 52 from below.

  Here, the “substantially horizontal direction” includes a direction along the horizontal plane in a state where the engine 11 is mounted on the vehicle, and also includes a direction intersecting with the horizontal plane at a slight angle. Similarly, “substantially upward” and “substantially downward” include a direction along the vertical plane when the engine 11 is mounted on the vehicle, and also includes a direction intersecting with the vertical plane at a slight angle. .

  In the present embodiment, the lateral hole portion 52 is provided in the oil separation chamber 41 at a location close to the annular protrusion 44. In the oil separation chamber 41, around the side hole portion 52, a flange portion 56 is integrally provided on the side wall portion 42 in a state of being connected to the annular protrusion 44. The flange portion 56 protrudes from the outer wall surface 43. The horizontal hole 52 is closed by the cover 45 described above, but may be closed by a stopper.

  Further, the horizontal hole portion 52, the upper vertical hole portion 53, and the lower vertical hole portion 54 are located in an intermediate portion with respect to the arrangement direction of the gas passages 32 and 33 (left and right direction in FIG. 2). Both the upper vertical hole portion 53 and the lower vertical hole portion 54 are formed by casting. On the other hand, the main part of the horizontal hole 52 is formed by casting, and machining such as cutting is performed as necessary. The upper vertical hole portion 53 and the lower vertical hole portion 54 are connected to different positions in the direction along the axis (left and right direction in FIG. 3) with respect to the horizontal hole portion 52.

  A part of the lower vertical hole portion 54 (a portion below a connection portion with an oil discharge passage 55 described later) returns the oil O separated from the blow-by gas G in the oil separation chamber 41 to the crank chamber 27. It also serves as an oil return passage.

  The oil discharge passage 55 is a passage for allowing the oil separation chamber 41 and the lower vertical hole portion 54 (oil return passage) to communicate with each other, and is formed by drilling. The inner diameter of the oil discharge passage 55 is set smaller than the inner diameter of the gas passages 32 and 33, and the flow passage area of the oil discharge passage 55 is smaller than the flow passage area of the gas passages 32 and 33. . The oil discharge passage 55 opens at a location spaced apart from the bottom 47 of the oil separation chamber 41 by a certain distance or more on the outer wall surface 43 of the side wall portion 42, and extends in a substantially horizontal direction to form a lower vertical hole portion 54 (oil return passage). It is connected to. The “substantially horizontal direction” includes the direction along the horizontal plane in a state where the engine 11 is mounted on the vehicle, as in the case of the horizontal hole portion 52, and is slightly lower than the horizontal plane as it approaches the lower vertical hole portion 54. The direction which intersects with a certain angle is also included.

  Here, the reason why the oil discharge passage 55 is constituted by a hole extending in a substantially horizontal direction is as follows. If a drilling tool is used to open an oil discharge passage 55 that opens to the bottom 47 of the oil separation chamber 41 and extends downward, the flange portion 56 around the side hole portion 52 has a substantially vertical direction. There is a risk of interference with the cutting tool. On the other hand, when the hole extending in the substantially horizontal direction is made as the oil discharge passage 55, the flange portion 56 described above does not easily interfere with the cutting tool moving in the substantially horizontal direction.

  In addition, the oil discharge passage 55 is provided at a position that is spaced apart from the bottom 47 of the oil separation chamber 41 by a certain distance or more in order to prevent the blade from hitting the bottom 47 during drilling. This is to prevent the force from being biased.

Further, in the oil separator 40 of the present embodiment, an inclined portion and an oil reservoir 60 are formed at the bottom 47 of the oil separation chamber 41 as shown in FIGS.
The inclined portion is inclined so as to become higher as the distance from the oil discharge passage 55 increases. In other words, the inclined portion is inclined with respect to the horizontal plane H. The inclined portion is composed of a first inclined portion 57 and a second inclined portion 58 that are centered on the oil reservoir 60 and become higher as the distance from the oil reservoir 60 increases. One of the first inclined portion 57 and the second inclined portion 58 is inclined at a constant (single) angle so as to become higher as the distance from the other increases. No depression is formed on the upper surfaces of the first inclined portion 57 and the second inclined portion 58. The angle (gradient) that each of the first inclined portion 57 and the second inclined portion 58 forms with the horizontal plane H is greater than 0 degrees.

  The oil reservoir 60 is adjacent to the lowermost portions of the first inclined portion 57 and the second inclined portion 58, and is positioned lower than the lowermost portion. The oil reservoir 60 includes a pair of vertical wall portions 61 and a pair of sub inclined portions 62. The interval between the two vertical wall portions 61 is set larger than the inner diameter of the oil discharge passage 55. The both vertical wall portions 61 extend in the vertical direction with the oil discharge passage 55 interposed therebetween and in a state of being separated from the oil discharge passage 55. The upper end portion of each vertical wall portion 61 is connected to the lowermost portion of each inclined portion 57, 58. Both the sub-inclined portions 62 are portions constituting the bottom of the oil reservoir 60 and are inclined with respect to the horizontal plane H. Both the sub-inclined portions 62 are inclined so as to be the lowest below the oil discharge passage 55, centering on the oil discharge passage 55 and becoming higher as the distance from the oil discharge passage 55 increases. One of the sub-inclined portions 62 is inclined so as to become higher as the distance from the other increases. One end portion of each sub-inclined portion 62 is connected to each other below the oil discharge passage 55, and the other end portion is connected to the vertical wall portion 61. An oil reservoir 60 is constituted by the vertical wall portions 61, the secondary inclined portions 62, a part of the outer wall surface 43, and a part of the cover 45.

  The oil discharge passage 55 is opened at a location spaced apart from the sub-inclined portions 62 of the oil reservoir 60 upward by a certain distance. The lowermost part of the oil discharge passage 55 and the upper vicinity thereof face the oil reservoir 60. Further, the oil discharge passage 55 is also separated from both the vertical wall portions 61. The opening position (height) of the oil discharge passage 55 is the oil when the first inclined portion 57 and the second inclined portion 58 are not provided in the bottom 47 of the oil separation chamber 41 and the bottom 47 is formed horizontally. It is lower than the opening position of the discharge passage 55. In addition, the oil drain passage 55 has an opening position (height) in which the oil reservoir 60 is not provided in the bottom 47 of the oil separation chamber 41, and only the first inclined portion 57 and the second inclined portion 58 are provided in the bottom 47. It is lower than the opening position of the oil discharge passage 55 when formed.

  As described above, in order to prevent the perforation cutting tool from hitting one side, the oil discharge passage 55 that must be opened at a location spaced apart from the bottom 47 of the oil separation chamber 41 by a certain distance or more is opened at a lower location. The reason for this was as follows.

  (I) The bottom 47 of the oil separation chamber 41 is provided with inclined portions (first inclined portion 57 and second inclined portion 58) that become higher as the distance from the oil discharge passage 55 increases. This is because the lower part of 55 is lower. The oil discharge passage 55 can be opened at a lower position than when the inclined portions (the first inclined portion 57 and the second inclined portion 58) are not provided because the above-mentioned portion of the bottom 47 is lowered. It is.

  (Ii) The oil reservoir 60 is provided at a position adjacent to the lowermost part of the inclined parts (the first inclined part 57 and the second inclined part 58) and lower than the lowermost part. This is because the position below the oil discharge passage 55 at the bottom 47 is lower. This is because the oil discharge passage 55 can be opened at a lower position than the case where the oil reservoir 60 is not provided by the amount of the lower portion of the bottom 47.

  (Iii) The bottom portion 47 of the oil separation chamber 41 is formed at the bottom of the oil reservoir 60 by forming a sub-inclined portion 62 that is the lowest below the oil discharge passage 55 and becomes higher away from the oil discharge passage 55. This is because the lower part of the oil discharge passage 55 is lower. This is because the oil discharge passage 55 can be opened at a lower position than when the bottom of the oil reservoir 60 is horizontal (not inclined) by the amount of the lower portion of the bottom 47.

  Furthermore, in this embodiment, as shown in FIG. 2, the gas inlets 32 </ b> A and 33 </ b> A of the gas passages 32 and 33 are opened above the oil discharge passage 55. Further, the inner diameter of each gas passage 32, 33 is set larger than the inner diameter of the oil discharge passage 55, and each gas passage 32, 33 has a larger flow area than that of the oil discharge passage 55. In the present embodiment, the inner diameters of the gas passages 32 and 33 are both set to 1.1 times the inner diameter of the oil discharge passage 55.

Next, the operation of the oil separator 40 of the present embodiment configured as described above will be described.
The blow-by gas G generated by the operation of the engine 11 flows through the gas passages 32 and 33 from the crank chamber 27 and flows into the oil separation chamber 41 from the gas inlets 32A and 33A. In the process in which the blow-by gas G flows through the oil separation chamber 41, the mist-like oil contained in the blow-by gas G comes into contact with the inner wall surface of the oil separation chamber 41 due to a collision or the like. Liquefied and separated from blow-by gas G. The separated oil O drops or flows down in the oil separation chamber 41 by its own weight, and then flows to the low side along the first inclined portion 57 or the second inclined portion 58, and the oil reservoir 60 has both sides thereof. Inflow from. Of the oil O that has flowed into the oil reservoir 60, the oil O that is located higher than the lowest part of the oil discharge passage 55 is discharged from the oil separation chamber 41 through the oil discharge passage 55. The discharged oil O flows down in the oil return passage (lower vertical hole portion 54) and is returned to the crank chamber 27.

  On the other hand, the oil O in the cylinder head 13 is returned to the crank chamber 27 through the oil passage (the upper vertical hole portion 53, the horizontal hole portion 52, and the lower vertical hole portion 54) in order, as indicated by an arrow in FIG. .

  Here, the amount of oil O discharged from the oil discharge passage 55 (or remaining without being discharged) varies depending on the position of the lowermost portion of the oil discharge passage 55. The lower the oil discharge passage 55 is, the more oil O is discharged (or the amount of oil O that remains without being discharged becomes smaller).

  In this respect, in the present embodiment, as described above, the opening position (height) of the oil discharge passage 55 is the same as the first inclined portion 57 and the second inclined portion 58 provided in the bottom 47 of the oil separation chamber 41. It is lower than the opening position of the oil discharge passage 55 when the bottom 47 is formed horizontally and is not inclined. The opening position (height) of the oil discharge passage 55 is the opening of the oil discharge passage 55 when the first inclined portion 57 and the second inclined portion 58 are provided but the oil reservoir portion 60 is not provided. Lower than position. Therefore, the amount of oil O discharged from the oil discharge passage 55 increases (the amount of oil O remaining in the oil separation chamber 41 without being discharged decreases).

  In addition to this, the oil O is collected in the oil reservoir 60. Therefore, the area (surface area) of the oil O that comes into contact with the exhaust component in the blow-by gas G in the oil separation chamber 41 is such that the first inclined portion 57 and the second inclined portion 58 are not provided at the bottom 47 of the oil separation chamber 41. The bottom 47 is smaller than the case where it is formed horizontally and is not inclined. This is because the oil O remains over a wide area of the bottom portion 47 when the bottom portion 47 is formed horizontally and is not inclined.

  The surface area of the oil O is smaller than that in the case where the oil reservoir 60 is not provided although the first inclined portion 57 and the second inclined portion 58 are provided in the bottom portion 47. In this case, the oil O is collected at the lower portion of the first inclined portion 57 and the second inclined portion 58. For this reason, the oil O remains over a relatively wide area of the bottom portion 47, although not as much as when the bottom portion 47 is provided horizontally and not inclined.

  And, as described above, both of the fact that the amount of oil O remaining in the oil separation chamber 41 itself is reduced and the area (surface area) where the oil O comes into contact with the exhaust component in the blow-by gas G are reduced, The amount of sludge generated when the oil O reacts with exhaust components and the like is reduced.

  By the way, among the blow-by gas passages 31, the gas passages 32 and 33 connected to the oil separation chamber 41 at the gas inlets 32 </ b> A and 33 </ b> A are also opened at the outer wall surface 43 of the side wall portion 42 and connected to the oil separation chamber 41. Also in the oil discharge passage 55, the blow-by gas G can pass through, and the oil O after the separation can pass through.

  In this regard, in the present embodiment in which the gas inlets 32A and 33A are opened above the oil discharge passage 55, the oil O that has been separated and dropped or flowed down to the bottom 47 of the oil separation chamber 41 is gas inlets 32A and 33A. Since the oil is first discharged from the lower oil discharge passage 55, it is difficult to flow into the gas passages 32 and 33 from the gas inlets 32A and 33A. Therefore, it is difficult for the oil O to prevent the flow of the blow-by gas G from the gas inlets 32 </ b> A and 33 </ b> A into the oil separation chamber 41. Along with this, the flow amount of the blow-by gas G in the oil discharge passage 55 is reduced, and the discharge of the oil O in the oil discharge passage 55 is hardly hindered by the blow-by gas G.

  In the present embodiment in which each gas passage 32, 33 has a larger inner diameter (flow passage area) than the oil discharge passage 55, the gas passages 32, 33 are more effective against the blow-by gas G than the oil discharge passage 55. The flow resistance is small and the blow-by gas G flows through the gas passages 32 and 33 more easily than the oil discharge passage 55. Accordingly, the flow amount of blow-by gas G in the oil discharge passage 55 is reduced. As a result, also in this respect, the discharge of the oil O in the oil discharge passage 55 is hardly hindered by the blow-by gas G.

According to the embodiment described in detail above, the following effects can be obtained.
(1) The oil separation chamber 41 is provided in the middle of the blow-by gas passage 31 so as to face the outer wall surface 43 of the side wall portion 42 of the cylinder block 12. An oil return passage (lower vertical hole portion 54) extending substantially vertically in the side wall portion 42 is provided. An oil discharge passage 55 is provided in the outer wall surface 43 of the side wall portion 42, which opens at a location spaced upward from the bottom portion 47 of the oil separation chamber 41 and is connected to the oil return passage (lower vertical hole portion 54). A first inclined portion 57 and a second inclined portion 58 that incline so as to become higher toward the bottom 47 of the oil separation chamber 41 away from the oil discharge passage 55, and lowermost portions of the first inclined portion 57 and the second inclined portion 58. And an oil reservoir 60 positioned lower than the lowermost part. The oil discharge passage 55 is opened at a location spaced upward from the bottom of the oil reservoir 60.

  Therefore, the oil discharge passage 55 can be opened at a lower position on the outer wall surface 43 of the side wall portion 42, and more oil O can be efficiently discharged from the oil discharge passage 55. Further, by collecting the oil O in the oil reservoir 60, the area (surface area) where the oil O contacts the exhaust component in the blow-by gas G can be reduced. As a result, it is possible to reduce the amount of sludge generated when the oil O reacts with the exhaust components and the like.

(2) A sub-inclined portion 62 is formed at the bottom of the oil reservoir 60 that is lowest below the oil discharge passage 55 and increases as the distance from the oil discharge passage 55 increases.
Therefore, the oil discharge passage 55 can be opened at a lower position, and more oil O can be discharged from the oil discharge passage 55.

(3) The inclined portion is constituted by a first inclined portion 57 and a second inclined portion 58 that are centered on the oil reservoir 60 and become higher as the distance from the oil reservoir 60 increases.
Therefore, the oil O separated from the blow-by gas G in the oil separation chamber 41 can be efficiently collected in the oil reservoir 60 from both sides.

(4) The entire bottom portion 47 of the oil separation chamber 41 is configured by the inclined portions (the first inclined portion 57 and the second inclined portion 58).
Therefore, most of the oil O separated from the blow-by gas G in the oil separation chamber 41 is collected in the oil reservoir 60 by the inclined portions (the first inclined portion 57 and the second inclined portion 58) and discharged from the oil discharge passage 55. be able to.

  (5) Utilizing an existing oil passage (upper vertical hole portion 53, horizontal hole portion 52, lower vertical hole portion 54) for returning the oil O of the cylinder head 13 to the crank chamber 27, a part thereof (lower vertical hole portion) 54) constitutes an oil return passage.

Therefore, the number of passages for returning the oil O to the crank chamber 27 can be reduced as compared with the case where the oil return passage is provided separately from the oil passage.
(6) The gas inlets 32 </ b> A and 33 </ b> A of the blow-by gas passage 31 (gas passages 32 and 33) in the oil separation chamber 41 are opened above the oil discharge passage 55.

  Therefore, it is possible to suppress the inflow of the blow-by gas G from the gas inlets 32A and 33A from being blocked by the oil O. Further, it is possible to suppress the discharge of the oil O from the oil discharge passage 55 from being obstructed by the blow-by gas G.

(7) The upstream portion of the blow-by gas passage 31 with respect to the oil separation chamber 41 is constituted by gas passages 32 and 33 having a larger flow passage area than the oil discharge passage 55.
Therefore, the blow-by gas G in the crank chamber 27 can be easily introduced into the oil separation chamber 41 through the gas passages 32 and 33. As a result, the flow amount of the blow-by gas G in the oil discharge passage 55 can be reduced, and the discharge of the oil O from the oil discharge passage 55 can be prevented from being hindered by the blow-by gas G.

Note that the present invention can be embodied in another embodiment described below.
<About blow-by gas passage 31>
The upstream portion of the blow-by gas passage 31 with respect to the oil separation chamber 41 may be configured by a number different from that in the above embodiment, that is, one or three or more gas passages.

  The height of each of the gas inlets 32A and 33A can be changed on condition that it is higher than the oil discharge passage 55. In this case, the heights of the gas inlets 32A and 33A may be the same or different from each other.

  The flow passage area (inner diameter) of each of the gas passages 32 and 33 can be changed on condition that the flow passage area (inner diameter) of the oil discharge passage 55 is larger. In this case, the flow passage areas (inner diameters) of the gas passages 32 and 33 may be the same or different.

<About the oil separation chamber 41>
The inclined portion may be provided only on a part of the bottom 47 of the oil separation chamber 41. Even in this case, the effect of efficiently discharging the oil O from the oil discharge passage 55 can be obtained.

-The 1st inclination part 57 and the 2nd inclination part 58 may incline at the same angle mutually, and may incline at a different angle.
-The 1st inclination part 57 may incline by a single angle, and an inclination angle (gradient) may change according to a site | part. The same applies to the second inclined portion 58.

In the above embodiment, the inclined portion may be configured by only one of the first inclined portion 57 and the second inclined portion 58.
<About the oil return passage>
The oil passage (upper vertical hole portion 53, horizontal hole portion 52, lower vertical hole portion 54) only needs to constitute at least a part (also serves as) an oil return passage. Therefore, the oil return passage may be constituted by the horizontal hole portion 52 and the upper vertical hole portion 53 without being limited to the lower vertical hole portion 54.

An oil return passage may be provided separately from the oil passage (upper vertical hole portion 53, horizontal hole portion 52, lower vertical hole portion 54).
<Oil discharge passage 55>
The oil discharge passage 55 may be opened not only at the lowermost portion and the vicinity thereof but also at other portions so as to face the oil reservoir 60.

<About the oil reservoir 60>
-The bottom part of the oil pool part 60 may be formed only by one sub-inclination part 62, and may be formed horizontally.

<Others>
The present invention can be applied to a blow-by gas processing apparatus in which the blow-by gas passage also serves as an oil return passage, as in the above-described Patent Document 1.

  The oil separator 40 of the present invention can be applied to a type of blow-by gas processing apparatus that does not have a function of introducing outside air into the crank chamber 27 and reducing the concentration of the blow-by gas G in the crank chamber 27. In this case, the blow-by gas G flows through the blow-by gas passage 31 instead of the mixture of the blow-by gas G and the outside air in the above embodiment. Then, when the blowby gas G passes through the blowby gas processing device, the mist-like oil O is separated from the blowby gas G.

  DESCRIPTION OF SYMBOLS 11 ... Gasoline engine (internal combustion engine), 12 ... Cylinder block, 13 ... Cylinder head, 18 ... Combustion chamber, 19 ... Intake passage, 27 ... Crank chamber, 30 ... Blow-by gas processing apparatus, 31 ... Blow-by gas passage, 32, 33 ... Gas passage, 32A, 33A ... Gas inlet, 40 ... Oil separator, 41 ... Oil separation chamber, 42 ... Side wall, 43 ... Outer wall, 47 ... Bottom, 54 ... Lower vertical hole (oil passage, oil return passage) , 55 ... oil discharge passage, 57 ... first inclined part (inclined part), 58 ... second inclined part (inclined part), 60 ... oil reservoir part, 62 ... sub-inclined part, G ... blow-by gas, O ... oil.

Claims (5)

The blow-by gas leaked from the combustion chamber of the internal combustion engine to the crank chamber is provided in a blow-by gas processing device that processes the blow-by gas by returning it to the intake passage through the blow-by gas passage.
An oil separation chamber in the middle of the blow-by gas passage, facing the outer wall surface of the side wall portion of the cylinder block, and separating oil from the blow-by gas;
An oil return passage extending substantially vertically in the side wall portion;
An oil separator of a blow-by gas processing device comprising an oil discharge passage that opens at a location spaced upward from the bottom of the oil separation chamber on the outer wall surface of the side wall portion and is connected to the oil return passage,
In the bottom part of the oil separation chamber, an inclined part that inclines so as to become higher away from the oil discharge passage, and an oil reservoir part that is adjacent to the lowermost part of the inclined part and is located lower than the lowermost part. And are formed,
The oil separator for a blow-by gas processing apparatus, wherein the oil discharge passage is opened at a location spaced upward from the bottom of the oil reservoir. 2. The oil separator of the blow-by gas processing apparatus according to claim 1, wherein a sub-inclined portion is formed at a bottom portion of the oil reservoir portion that is lowest below the oil discharge passage and becomes higher as the distance from the oil discharge passage increases. . An oil passage for returning the oil of the cylinder head to the crank chamber is provided in the side wall portion so as to extend in a substantially vertical direction.
The oil separator of the blow-by gas processing device according to claim 1 or 2, wherein the oil return passage is configured by at least a part of the oil passage, and the oil discharge passage is connected to the oil passage. In the blow-by gas passage, a portion connected to the oil separation chamber upstream of the oil separation chamber is opened above the oil discharge passage as a gas inlet of the blow-by gas to the oil separation chamber. The oil separator of the blow-by gas processing apparatus as described in any one of Claims 1-3. The blow-by gas according to any one of claims 1 to 4, wherein an upstream portion of the blow-by gas passage from the oil separation chamber is constituted by a gas passage having a larger flow passage area than the oil discharge passage. Oil separator for processing equipment.