JP2010164017A - Lubrication device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil circulation device preventing the flow of blowby gas into an oil return passage. <P>SOLUTION: The lubrication device for an engine E is provided for returning engine oil separated from blowby gas into an oil pan 3. It includes a blowby gas passage (a passage 20 and a breather chamber 9) for communicating a crank chamber 17 with an intake system, an oil separator 25 mounted in the blowby gas passage, the oil return passage (first-third return passages 26, 29, 30 and an oil drain pipe 31) connected at one end to the oil separator 25 and having a flow-out port 31a opened in proximity to the bottom of the oil pan 3 (a bottom 16a of a lower case 16), and a baffle 32 provided outside the oil return passage for covering the flow-out port 31a in its isolated condition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lubricating device for an internal combustion engine, and more particularly to a structure for returning engine oil separated from blow-by gas to an oil pan.

  Some internal combustion engines of automobiles are equipped with a blow-by gas recirculation device that recirculates blow-by gas in a crank chamber to an intake system. Since blow-by gas contains engine oil, the blow-by gas recirculation device is provided with an oil separator, and blow-by gas from which oil mist has been removed by the oil separator flows into the intake system. The engine oil separated from the blow-by gas by the oil separator is returned to the oil pan through the oil return passage.

  Since the suction negative pressure of the intake system acts on the blow-by gas recirculation device, the pressure in the oil separator and the oil recirculation passage is lower than that in the crank chamber. Therefore, when the outlet (downstream end) of the oil recirculation passage is located above the level of the engine oil stored in the oil pan, the crank chamber and the blow-by gas reduction device communicate with each other via the oil recirculation passage. As a result, the blow-by gas in the crank chamber flows into the intake system without the engine oil being removed by the oil separator.

  As a method for solving this problem, there is a method in which an oil reservoir is provided in an oil pan and an outlet of an oil recirculation passage is arranged in engine oil held in the oil reservoir (for example, Patent Document 1). In this configuration, a constant amount of engine oil is always held in the oil reservoir, and the outlet of the oil return passage is always immersed in the engine oil, so that blow-by gas in the crank chamber flows into the oil return passage. Can be prevented.

JP 2008-19743 A

  However, when an oil reservoir is provided in the oil pan, the structure of the oil pan is complicated, and there is a problem that the oil pan becomes large in order to secure a space for forming the oil reservoir in the oil pan. is there.

  The present invention has been made in view of the above problems, and is an oil circulation device that can prevent the flow of blow-by gas into the oil recirculation passage without providing an oil reservoir separately and with a simple structure. The purpose is to provide.

  In order to solve the above-mentioned problems, the first invention of the present invention supplies engine oil stored in an oil pan (3) to each part of an internal combustion engine (engine E) and supplies engine oil separated from blow-by gas. In a lubricating device for an internal combustion engine that recirculates to an oil pan, a blow-by gas passage (passage 20, breather chamber 9) that communicates a crank chamber (17) with an intake system, and the blow-by gas passage are interposed between the blow-by gas and engine An oil separator (25) for separating oil, and an oil recirculation passage (first to third oil passages) whose one end is connected to the oil separator and whose outlet (31a) is opened close to the bottom (16a) of the oil pan. The third oil recirculation passages 26, 29, 30 and the oil drain pipe 31) and the outside of the oil recirculation passage. Characterized in that it comprises a baffle (32) covering in a state spaced with the outlet.

  According to this configuration, even when an automobile equipped with an internal combustion engine suddenly accelerates, suddenly decelerates, turns left and right, etc., and the engine oil flows in the oil pan in one direction due to inertia, In order to hold in the vicinity of the outlet, the outlet is always immersed in engine oil. Therefore, it is possible to prevent the blow-by gas in the oil pan from flowing into the oil recirculation passage. Further, since there is no need to provide an oil reservoir in the oil pan, the oil pan can be reduced in size and simplified.

  According to a second aspect of the present invention, in the first aspect, the baffle has a cup shape that opens downward, the opening end of the baffle contacts the bottom of the oil pan, and the opening communicates the inside and the outside. (33) is formed at least at the top, and the outlet is located inside the baffle.

  According to this configuration, the air in the baffle is released to the outside through the opening, so that the air is not retained in the baffle and is filled with the engine oil, and the inlet is more reliably immersed in the engine oil. It becomes like this.

  According to a third aspect of the present invention, in the second aspect, the opening is formed in a portion of the baffle closest to the inner wall of the oil pan.

  According to this configuration, even when an automobile equipped with an internal combustion engine performs rapid acceleration or the like, engine oil can be retained in the baffle more reliably. In addition, the opening can be enlarged, and the engine weight can be reduced.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the baffle is integrally formed with the oil return passage.
According to this configuration, since it is not necessary to separately manufacture and assemble the baffle, it is possible to reduce the number of parts and the number of steps in the assembling process.

  By configuring as described above, the outlet is immersed in the engine oil stored in the oil pan, and the inflow of blow-by gas into the oil return passage through the outlet is prevented.

It is a perspective view which fractures | ruptures and shows the V-type engine which concerns on embodiment. It is II-II sectional drawing of FIG. It is the (a-1, b-1, c-1) perspective view and (a-2, b-2, c-2) bottom view which show the baffle which concerns on deformation | transformation embodiment.

  Hereinafter, an embodiment in which the present invention is applied to a V-type engine of an automobile will be described in detail with reference to the drawings. FIG. 1 is a cutaway perspective view of an internal combustion engine according to an embodiment. FIG. 1 shows a state in which the intake pipe, the exhaust pipe, the cylinder head, and the like are removed. The engine E according to the present embodiment is arranged horizontally in the engine room so that the upper left side of the plane of FIG. 1 is the front of the vehicle. Hereinafter, the vehicle traveling direction will be described as forward, the vehicle width direction as right or left, and the vertical direction as upward or downward.

  As shown in FIG. 1, the engine E includes a cylinder block 1 in which a crankcase 2 is integrally formed at a lower portion thereof and an oil pan 3 fastened to the lower portion of the cylinder block 1 as main components. The cylinder block 1 includes a front and rear cylinder banks each having a cylinder bore (not shown) in an upper part of a crankcase 2 arranged in a V shape at a predetermined angular interval. And a head cover is attached.

  A concave portion 7 surrounded by a front cylinder bank 4, a rear cylinder bank (not shown), and a left wall portion 5 and a right wall portion 6 is formed in the upper portion of the cylinder block 1. A lid 8 is fastened with a bolt via a gasket at the upper part of the recess 7, and a breather chamber 9 that forms part of the blow-by gas passage is defined.

  A plurality of crank journal walls 11 project from the top of the crankcase 2 downward. A bearing beam 12 is fastened to the lower part of the crank journal wall 11, and a crankshaft 14 is pivotally supported between the crank journal wall 11 and the bearing beam 12 via a bearing 13.

  The oil pan 3 is composed of an upper case 15 and a lower case 16. The upper case 15 has a box shape opened downward, and is fastened to the lower part of the crankcase 2 with bolts at the upper part. The lower case 16 has a box shape opened upward, and is fixed to the upper case 15 with bolts so that the opening coincides with the opening of the upper case 15.

  A crank chamber 17 is defined by the upper part of the crankcase 2, the crank journal wall 11, the bearing beam 12 and the upper case 15. A through hole 18 is formed in the upper part of the upper case 15 to communicate the crank chamber 17 and the oil pan 3. The engine oil accumulated in the lower portion of the crank chamber 17 passes through the through hole 18 and is returned to the oil pan 3. Further, the blow-by gas in the crank chamber 17 passes through the through hole 18 and flows into the oil pan 3. The white arrow in the figure indicates the flow of blow-by gas.

  An opening 21 is formed in the upper part of the upper case 15, while a passage 20 is formed in the cylinder block 1 so that one end communicates with the opening 21 and the other end opens in the right wall 6 of the recess 7. . The blow-by gas in the oil pan 3 passes through the passage 20 and flows into the recess 7 (that is, the breather chamber 9). The passage 20 and the breather chamber 9 form a part of the blow-by gas passage.

  The breather chamber 9 is provided with an oil separator 25 fixed to the lower surface of the lid 8. The oil separator 25 includes a box-shaped main body 25a, a blow-by gas introduction hole 25b formed in a side portion of the main body 25a, a blow-by gas discharge pipe 25c protruding from the upper portion of the main body 25a, and a lower portion of the main body 25a. An oil discharge pipe 25d provided and a plurality of baffle plates 25e provided inside the main body 25a are provided.

  The blow-by gas that has flowed into the oil separator 25 through the blow-by gas introduction hole 25b collides with the baffle plate 25e before reaching the blow-by gas discharge pipe 25c, and the engine oil contained in the blow-by gas is baffled plate 25e. Attached to and removed. The engine oil adhering to the baffle plate 25e is collected at the bottom of the oil separator 25 and discharged to the outside of the oil separator 25 through the oil discharge pipe 25d.

  The blow-by gas discharge pipe 25 c extends to the outside of the breather chamber 9 through a through hole 8 a formed in the lid 8. A breather hose (not shown) communicating with the intake system is connected to the tip of the blow-by gas discharge pipe 25c. The breather hose forms part of the blow-by passage.

  At the bottom of the recess 7, the other end of the first oil recirculation passage 26 whose one end opens at the side of the cylinder block 1 is open. The tip of the oil discharge pipe 25d is fitted into the opening of the first oil recirculation passage 26 on the recess 7 side. An opening in the side of the cylinder block 1 of the first oil return passage 26 is surrounded by a rib 27 that protrudes from the side of the cylinder block 1. The rib 27 extends downward and reaches the lower end of the cylinder block 1. A wall portion 27 a is provided at a portion of the rib 27 that contacts the upper portion of the upper case 15. A through hole 28 is formed in the wall portion 27a. A crankcase cover (not shown) constituting the left end of the crank chamber 17 is fastened to the projecting end of the rib 27 by a bolt, and the second oil return passage 29 is formed by the rib 27, the cylinder block 1, and the crankcase cover. Defined.

  A third oil return passage 30 having one end communicating with the through hole 28 and the other end opening into the oil pan 3 is formed in the upper portion of the upper case 15. One end of a tubular oil drain pipe 31 is fitted into the opening end of the third oil recirculation passage 30 on the oil pan side. The other end of the oil drain pipe 31 extends to the bottom 16a of the lower case 16 to form an outlet 31a.

  FIG. 2 is a cross-sectional view showing a main part of the V-type engine according to the embodiment. The outflow port 31a is disposed in the oil pan 3 at a position displaced to the left of the central portion. A cup-shaped (hemispherical) baffle 32 that opens downward is provided in the vicinity of the outlet 31a of the oil drain pipe 31 (see a-1 and a-2 in FIG. 4. A-1 is a perspective view). (A-2 is a bottom view). The oil drain pipe 31 and the baffle 32 are made of resin and are integrally formed by injection molding or the like.

  The baffle 32 is provided so as to surround the periphery of the oil drain pipe 31 so that the outlet 31a is disposed therein. An opening 33 is formed on the left side of the baffle 32 from the lower part to the upper part. The opening 33 is formed in a portion of the baffle 32 closest to the inner wall of the oil pan 3 (in this embodiment, the left portion of the baffle 32).

  The opening end (lower end) 32a of the baffle 32 is formed smoothly and is in contact with the bottom 16a of the lower case 16 on the entire circumference. Therefore, the engine oil cannot pass between the lower end of the baffle 32 and the bottom portion 16 a of the lower case 16. It should be noted that a flexible sealing member may be provided at the opening end 32a of the baffle 32 to enhance the adhesion with the bottom 16a of the lower case 16. Further, a recess that engages with the opening end 32a of the baffle 32 may be provided in the bottom portion 16a of the lower case 16, and the opening end 32a of the baffle 32 and the bottom portion 16a of the lower case 16 may be more reliably joined. Further, the opening end 32a of the baffle 32 and the bottom portion 16a of the lower case 16 may be integrally joined by welding, bolt fastening, or the like.

  As shown in FIG. 1, the engine oil separated from the blow-by gas is discharged from an oil discharge pipe 25d of the oil separator 25 as shown by a black arrow in the drawing, and constitutes an oil return passage. 26, passes through the second oil recirculation passage 29, the third oil recirculation passage 30, and the oil drain pipe 31 and recirculates into the oil pan 3.

  Engine oil is stored inside the oil pan 3, and an oil strainer 41 that constitutes the upstream end of the oil supply passage is disposed in a state of being immersed in the engine oil. The oil strainer 41 includes an upper cup member 41a with a hook opening downward and a lower cup member 41b with a hook opening upward as outer shells. The upper cup member 41a and the lower cup member 41b are joined to each other with a mesh (not shown) interposed therebetween. An inflow port (not shown) is formed at the bottom of the lower cup member 41b.

  An oil supply pipe 44 connected to an oil pump (not shown) is connected to the upper cup member 41a. The upper cup member 41a is connected to and supported by the other end of a bracket 45 whose one end is connected to the upper portion of the upper case 15. The upper cup member 41 a is connected to the other end of a bracket 46 whose one end is connected to the vicinity of the outlet of the oil drain pipe 31. Thereby, the oil drain pipe 31 is supported by the oil strainer 41. The rigidity of each bracket 45, 46 is increased by bead processing.

  Next, the operation of the embodiment will be described. As shown in FIG. 2, when an automobile equipped with the engine E turns left and an acceleration of 0.8 G is applied, an inertial force acts on the engine oil and moves to the right side. As indicated by the chain line A. If the baffle 32 is not present, the outlet 31a is positioned above the engine oil level. However, part of the engine oil is restrained from flowing by the baffle 32 and stays in the baffle 32. The level of engine oil in the baffle 32 at this time is indicated by a two-dot chain line B. By arranging the baffle 32, the outlet 31a is immersed in the engine oil staying in the baffle 32 when the automobile turns left. Therefore, blow-by gas in the oil pan 3 does not flow into the oil drain pipe 31 through the outflow port 31a.

  When the vehicle turns to the right and an acceleration of 0.8 G is applied, the engine oil level is indicated by a two-dot chain line C, but the engine oil has an outlet 31 a disposed in the oil pan 3. Since the fluid flows to the left side, the outlet 31a is immersed in the engine oil without the baffle 32. Therefore, the opening 33 can be formed larger on the left side of the baffle 32. Since the air in the baffle 32 is released to the outside through the opening 33, the inside of the baffle 32 is filled with engine oil. And by making the opening part 33 large, the weight of the baffle 32 becomes small and the reduction of an engine weight can be aimed at.

  Also during the rapid acceleration and sudden deceleration of the automobile, the baffle 32 can retain the engine oil in the interior and keep the outlet 31a immersed in the engine oil, as in the case of the left turn described above.

  Since the outlet 31a is always immersed in the engine oil by the baffle 32, the baffle 32 can be arranged at an arbitrary position in the oil pan 3. Therefore, the degree of freedom in layout increases and the oil drain pipe 31 can be shortened to reduce the weight.

  Further, even if the inlet of the oil strainer 41 and the outlet 31 a are arranged close to each other, the suction pressure to the inlet of the oil strainer 41 by the oil pump is difficult to be applied to the outlet 31 a by the baffle 32. The phenomenon that the air present in the oil drain pipe 31 is bitten by the oil strainer 41 is suppressed.

  Since the baffle 32 is fixed to the oil drain pipe 31, even if the oil drain pipe 31 is displaced due to the movement of engine oil or inertia force, the baffle 32 also moves along with the oil drain pipe 31, and the outlet 31a. Is always immersed in engine oil.

  Next, a modified embodiment in which only the shape of the baffle 32 is changed will be described as a modified example of the above-described embodiment. Since the configuration other than the baffle is the same as that of the above-described embodiment, the description thereof is omitted. FIG. 3 is a (1) perspective view and (2) bottom view showing the baffle according to the embodiment. In FIG. 3, (a-1) and (a-2) are the perspective view and bottom view which show the baffle of embodiment mentioned above, (b-1) and (b-2) are 1st modified embodiment. It is the perspective view and bottom view which show the baffle of this, (c-1) and (c-2) are the perspective view and bottom view which show the baffle of 2nd deformation | transformation embodiment.

  As shown in (b-1) and (b-2) of FIG. 3, the baffle 50 in the first modified embodiment has a cup shape that opens downward, and is provided over the entire circumference around the oil drain pipe 31. It has been. The opening end (lower end) 50a of the baffle 50 is formed to be smooth and abuts with the bottom 16a of the lower case 16 over the entire circumference. The opening 51 is provided in the upper part of the baffle 50, and is formed smaller than the opening 33 according to the embodiment. With this configuration, the position of the opening 51 can be determined without considering the position of the outlet 31a in the oil pan 3. Since the entire periphery of the outlet 31a is surrounded by the baffle 50, the outlet 31a is immersed in the engine oil even during rapid acceleration of the automobile.

  As shown in (c-1) and (c-2) of FIG. 3, the baffle 60 in the second modified embodiment has a baffle 50 with an open end 50 a at the bottom in addition to the baffle 50 of the first modified embodiment. It is blocked by a wall 52. The opening 51 is arranged in the upper part as in the first modified embodiment. With this configuration, it is not necessary to consider the adhesion between the lower end of the baffle 60 and the bottom portion 16a of the lower case 16. That is, even if the adhesion between the baffle 60 and the bottom portion 16a of the lower case 16 is low, the engine oil is prevented from flowing out of the baffle 60, so the outlet 31a is always immersed in the engine oil. .

  Although the description of the specific embodiment is finished as above, the present invention is not limited to the above embodiment and can be widely modified. The oil drain pipe 31 and the baffle 32 may be formed separately from metal materials and may be coupled to each other by welding or the like. In the embodiment and the like, the baffle is formed in a hemispherical cup shape, but may be formed in a cylindrical shape or a box shape. The position, shape, and size of the opening can be appropriately changed in consideration of the position of the outlet in the oil pan, the shape of the baffle, and the like.

  3: oil pan, 9: breather chamber (blow-by gas passage), 15: upper case, 16: lower case, 17: crank chamber, 20: passage (blow-by gas passage), 25: oil separator, 26: first oil recirculation passage (Oil return passage), 29: second oil return passage (oil return passage), 30: third oil return passage (oil return passage), 31: oil drain pipe (oil return passage), 31a: outlet, 41: Oil strainer (oil supply passage), 32, 50, 60: baffle, 33, 51: opening, E: engine (internal combustion engine)

Claims (4)

In a lubricating device for an internal combustion engine that supplies engine oil stored in an oil pan to each part of the internal combustion engine and recirculates engine oil separated from blow-by gas to the oil pan,
A blow-by gas passage communicating the crank chamber and the intake system;
An oil separator interposed in the blow-by gas passage for separating engine oil from the blow-by gas;
An oil recirculation passage whose one end is connected to the oil separator and whose outlet is opened close to the bottom of the oil pan;
A lubricating device for an internal combustion engine, comprising: a baffle provided outside the oil recirculation passage and covering the outlet in a separated state. The baffle has a cup shape that opens downward, the opening end of the baffle abuts the bottom of the oil pan, and an opening that communicates the inside and the outside is formed at least at the top,
2. The internal combustion engine lubrication device according to claim 1, wherein the outlet is located inside the baffle.   The lubricating device for an internal combustion engine according to claim 2, wherein the opening is formed in a portion of the baffle closest to the inner wall of the oil pan.   The lubricating device for an internal combustion engine according to any one of claims 1 to 3, wherein the baffle is formed integrally with the oil return passage.

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