JP2007198311A - Oil recovery device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil recovery device for an internal combustion engine, capable of preventing oil from staying in a cylinder head beyond a permissible level as a result that oil resides in an oil return passage. <P>SOLUTION: The oil recovery device 30 is applied for the internal combustion engine which is mounted in a vehicle in the state that the oil return passage 24 intersects the vertical direction for guiding oil supplied to the cylinder head 4 to an oil pan. The oil recovery device 30 comprises an oil recovery passage 31 for guiding the oil out of the cylinder head 4 or the oil return passage 24, and a jet pump 32 for sucking the oil out of the oil recovery passage 31 to recover the oil supplied to the cylinder head. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an oil recovery device for an internal combustion engine that recovers oil supplied to a cylinder head of the internal combustion engine.

  The internal combustion engine is provided with an oil return passage for guiding the oil supplied to the cylinder head to the oil pan. The oil supplied to the cylinder head is returned to the oil pan by gravity while being guided to the oil return passage after lubricating each part. Note that Patent Document 1 and Patent Document 2 exist as prior art documents related to the present invention.

JP-A-3-175109 JP 2001-80372 A

  When an internal combustion engine mounted on a vehicle with such an oil return passage intersecting the vertical direction, typically a V-type internal combustion engine, is mounted vertically with respect to the vehicle, Inertial force directed outward in the turning direction acts on the oil in the oil return passage. As a result, the inertial force and the gravity acting on the oil are balanced in the direction along the oil return passage, or the inertial force overcomes the gravity, so that the oil cannot stop along the oil return passage and stops in the oil return passage. To do.

  When such a state is maintained and the flow of the oil return passage is delayed, oil is constantly supplied to the cylinder head, so that the oil accumulated in the cylinder head gradually increases. In particular, at the time of high-speed rotation in which the amount of oil supplied to the cylinder head increases, the oil tends to accumulate even if the vehicle turning state is maintained for a relatively short time. As a result, the oil accumulates in the cylinder head as the liquid level exceeds the permissible level, and if the condition is bad, the cylinder head may be filled with oil. Even when such a V-type internal combustion engine is placed horizontally on a vehicle, the same problem as described above may occur during acceleration or deceleration.

  When these problems occur, for example, when the oil level exceeds the opening position of the blow-by gas reduction passage (PCV passage) that opens in the cylinder head, the PCV passage is blocked with oil, and oil is blown from the PCV valve. May rise. Further, the oil leaks from the cylinder head cover or the amount of oil returned to the oil pan is insufficient. As a result, the amount of oil supplied to each part of the internal combustion engine may be insufficient.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an oil recovery device for an internal combustion engine that can prevent oil from accumulating in a cylinder head beyond an allowable level by oil remaining in the oil return passage.

  The oil recovery device of the present invention is applied to an internal combustion engine mounted on a vehicle in a state where an oil return passage for guiding oil supplied to a cylinder head to an oil pan intersects a vertical direction, and the oil supplied to the cylinder head An oil recovery device for an internal combustion engine for recovering oil, an oil recovery passage capable of guiding oil in the cylinder head or the oil return passage, and an oil suction means for sucking oil in the oil recovery passage; By solving this problem, the above-described problem is solved (claim 1).

  According to this oil recovery device, even when oil stops in the oil return passage due to the traveling state of the vehicle equipped with the internal combustion engine, the oil in the cylinder head or the oil return passage is guided to the oil recovery passage by the oil suction means. It is recovered. Therefore, it is possible to prevent oil from accumulating in the cylinder head as the oil exceeds the allowable level due to the oil remaining in the oil return passage. The internal combustion engine to which this oil recovery device is applied may be an internal combustion engine that is mounted on a vehicle in a state where an oil return passage that guides oil supplied to the cylinder head to the oil pan intersects the vertical direction. There is no limit. The oil recovery apparatus of the present invention is typically applied to a V-type internal combustion engine, but can also be applied to a horizontally opposed internal combustion engine. In applying the oil recovery apparatus of the present invention, the arrangement direction of the cylinders is not important, and any internal combustion engine that is mounted on a vehicle in a state where the oil return passage intersects the vertical direction may be used.

  The oil recovery device of the present invention may further include an oil reservoir that is connected to the oil recovery passage and can store oil (claim 2). In this case, since the oil in the oil reservoir portion can be stored, the rising speed of the oil level of the oil is reduced. For this reason, the chances of the oil suction by the oil suction means not being in time are reduced. In other words, since a margin can be provided for the oil suction operation by the oil suction means, it is possible to reliably prevent the oil from accumulating in the cylinder head beyond the allowable level. The position where the oil reservoir is provided is not particularly limited as long as it can communicate with the cylinder head or the oil return passage. For example, an oil reservoir may be provided in the cylinder head. In this case, the oil in the cylinder head can be reliably stored in the oil reservoir.

  In the oil recovery apparatus of the present invention, the configuration of the oil suction means is not limited and can be implemented in various modes. For example, the oil suction means may be realized by a suction pump using an internal combustion engine or an electric motor as a drive source.

  Further, as another aspect for realizing the oil suction means, there are an oil pump for supplying oil to the cylinder head, and an oil discharge passage connected to the oil pump for guiding the oil discharged from the oil pump. When provided in an internal combustion engine, as the oil suction means, the oil recovery passage is provided in the oil discharge passage and connected to the oil recovery passage, and utilizes the oil flow in the oil discharge passage. A jet pump for sucking the oil inside may be provided. Further, when the internal combustion engine is provided with a scavenge pump that pumps oil from the oil pan, an oil tank that can store the oil, and an oil discharge passage that connects the scavenge pump and the oil tank. The oil suction means is provided in the oil discharge passage of the lubrication apparatus and connected to the oil recovery passage, and sucks oil in the oil recovery passage using the oil flow in the oil discharge passage. A jet pump may be provided (claim 5).

  According to these aspects, the suction means can be realized by using an oil pump or a scavenge pump provided in the internal combustion engine. Therefore, compared to the above-described aspect in which a dedicated suction pump is used for oil recovery, the oil recovery is possible. Not only can the energy required be reduced, but also the number of parts can be reduced, making it easy to downsize the apparatus. In addition, the friction loss can be reduced as compared with an aspect in which a dedicated suction pump using an internal combustion engine as a drive source is provided, which can contribute to an improvement in fuel consumption.

  As described above, according to the oil recovery apparatus of the present invention, the oil recovery passage that can guide the oil in the cylinder head or the oil return passage, and the oil suction means that sucks the oil in the oil recovery passage. Therefore, even when oil stops in the oil return passage due to the traveling state of the vehicle equipped with the internal combustion engine, the oil is guided to the oil recovery passage by the oil suction means and recovered. Therefore, the oil can be prevented from accumulating in the cylinder head to the extent that the allowable level is exceeded by the oil remaining in the oil return passage.

(First form)
FIG. 1 is an overall configuration diagram showing an embodiment in which an oil recovery apparatus of the present invention is applied to an internal combustion engine. The internal combustion engine 1 is provided as a driving power source for a vehicle (not shown). The internal combustion engine 1 has two cylinder groups 2A and 2B in which four cylinders 2 are arranged in a line, and these cylinder groups 2A and 2B are arranged so as to form a predetermined bank angle. It is. In FIG. 1, a total of two cylinders 2 are shown, one for each of the cylinder groups 2A and 2B. The internal combustion engine 1 is mounted vertically on the vehicle, that is, mounted on the vehicle in a state where the traveling direction of the vehicle (direction perpendicular to the paper surface of FIG. 1) and the arrangement direction of the cylinders 2 are parallel to each other.

  The internal combustion engine 1 includes a cylinder block 3 in which each cylinder 2 is formed, a cylinder head 4 provided for each of the two cylinder groups 2A and 2B and connected to the upper side of the cylinder block 3, and a lower side of the cylinder block 3. And an oil pan 5 which is connected and holds lubricating oil. Pistons 6 arranged in a state where they can reciprocate in each cylinder 2 are connected to the crankshaft 7 via connecting rods 8, and the reciprocating motion of the pistons 6 is converted into rotational movement of the crankshaft 7. The configurations related to each of the cylinder groups 2A and 2B of the internal combustion engine 1 are equivalent to each other. Therefore, in the following, in order to avoid duplication of explanation, the configuration related to the cylinder group 2A of the internal combustion engine 1 will be described, and the description of the configuration related to the cylinder group 2B will be omitted. The cylinder head 4 is provided with an intake passage 10 and an exhaust passage 11 communicating with each cylinder 2, an intake valve 12 that opens and closes the intake passage 10, and an exhaust valve 13 that opens and closes the exhaust passage 11. Yes. The valves 12 and 13 are driven by a valve operating mechanism 15 that uses the output of the crankshaft 7 as a drive source.

  The internal combustion engine 1 is provided with a lubrication device 20 that circulates oil through a predetermined path in order to lubricate each part. The lubrication device 20 has an oil pump 21 for pumping up the oil in the oil pan 5 and pumping it to each part, and the oil pump 21 is driven by the output of the crankshaft 7. The oil discharged from the oil pump 21 is guided to the oil supply passage 22, while being guided to the relief passage 23 in order to adjust the amount of oil supplied to the oil supply passage 22. The oil supply passage 22 is branched into a plurality of branch passages (not shown), and these branch passages include passages for guiding oil to the cylinder head 4. The oil supplied to the cylinder head 4 is used, for example, for lubricating a movable part such as a cam or a valve lifter of the valve mechanism 15. The oil that has been lubricated to such a movable part passes through the cylinder head 4 and then is guided to the oil return passage 24 formed in the cylinder block 3. The oil return passage 24 is disposed so as to extend substantially parallel to the center line of the cylinder 2. That is, the oil return passage 24 of this embodiment intersects the vertical direction at an angle that is approximately half the bank angle with reference to the state in which the internal combustion engine 1 is mounted on a horizontally held vehicle. Therefore, at a normal time represented by the vehicle traveling at a constant speed on a horizontal plane, the oil guided to the oil return passage 24 falls by gravity along the oil return passage 24 and is returned to the oil pan 5.

  When the vehicle turns, an inertia force (so-called lateral G) outward in the turning direction acts. When the inertial force exceeds a limit determined by the inclination angle of the oil return passage 24, the oil stops in the oil return passage 24 and cannot fall to the oil pan 5, and the oil 100 is collected in the cylinder head 4. FIG. 2 is an explanatory view schematically showing the internal structure of the cylinder head 4 of the internal combustion engine 1 from the direction A in FIG. In the internal combustion engine 1, the permissible level Lp of the oil level L accumulated in the cylinder head 4 is set to the height of the opening position 16 a of the PCV passage 16. The internal combustion engine 1 is provided with a blow-by gas reduction device (PCV device) 17. The PCV device 17 guides blow-by gas leaked to the crankcase side to the PCV passage 16, and is provided in the cylinder head 4 (not shown). This is a well-known one that forcibly introduces blow-by gas into the intake passage 10 by opening and closing the PCV valve. If the level L of the oil 100 accumulated in the cylinder head 4 exceeds the allowable level Lp, the PCV passage 16 is blocked by the oil 100 and the oil blows up from the PCV valve. Therefore, as shown in FIG. 1, in this embodiment, the internal combustion engine 1 is provided with an oil recovery device 30 that recovers oil in the cylinder head 4 in order to prevent the oil accumulated in the cylinder head 4 from exceeding an allowable level. ing.

  The oil recovery device 30 includes an oil recovery passage 31 capable of guiding the oil in the cylinder head 4 and a jet pump 32 as oil suction means for sucking the oil in the oil recovery passage 31. One end 31 a of the oil recovery passage 31 is connected to an oil reservoir 33 that can store oil, and the other end 31 b is connected to a jet pump 32. The oil reservoir 33 is formed to open in the cylinder head 4 and extend in the direction in which the cylinders of the cylinder group 2A are arranged (see FIG. 2). The jet pump 32 is provided in a relief passage 23 connected to the oil pump 21, and is configured so that oil in the oil recovery passage 31 can be sucked using the flow of oil guided to the relief passage 23.

  FIG. 3 is an explanatory diagram illustrating details of the jet pump 32. The jet pump 32 includes a tapered nozzle portion 32a formed in the relief passage 23 and a housing portion 32b surrounding the relief passage 23 so as to cover the opening 32c formed in the relief passage 23 and positioned on the side of the nozzle portion 32a. And have. The housing portion 32b is joined to the outer peripheral surface of the relief passage 23, and an end portion 31b of the oil recovery passage 31 is opened inside the housing portion 32b. According to the jet pump 32, the pressure in the housing portion 32b is reduced by increasing the flow rate of the oil discharged from the oil pump 21 and guided to the relief passage 23 by the nozzle portion 32a, so that the oil in the oil recovery passage 31 is reduced. Can be sucked. The oil sucked from the oil recovery passage 31 is guided to the relief passage 23 through the opening 32c as shown by the arrow in FIG.

  According to the above embodiment, the oil in the cylinder head 4 is recovered in the oil pan 5 by the oil recovery device 30 even when the oil stops in the oil return passage 24 due to the traveling state of the vehicle on which the internal combustion engine 1 is mounted. . Therefore, it is possible to prevent the oil 100 accumulated in the cylinder head 4 from exceeding the allowable level Lp. Further, the jet pump 32 of the oil recovery device 30 can suck the oil in the oil recovery passage 31 using the oil flow in the relief passage 23. That is, oil can be sucked using the oil pump 21 provided in the internal combustion engine 1 as a drive source. Therefore, it is not necessary to prepare a dedicated drive source (for example, a suction pump or an electric pump driven by an internal combustion engine) for sucking oil, so that not only energy required for oil recovery can be reduced but also parts Since the number of points is reduced, it is easy to downsize the apparatus. In addition, the friction loss can be reduced as compared with an aspect in which a dedicated suction pump using an internal combustion engine as a drive source is provided, which can contribute to an improvement in fuel consumption.

  Further, since the jet pump 32 uses the flow of oil guided to the relief passage 23 of the oil pump 21, there is no possibility of adversely affecting the function of the lubricating device 20. That is, in the above embodiment, the oil supply passage 22 that supplies oil to each part of the internal combustion engine 1 or the oil flow in the branch passage branched from the oil supply passage 22 is used as compared with the case where the oil flow is used. There is no problem of reducing the oil supply amount or increasing the capacity of the oil pump 21 in order to compensate for such a decrease in the oil supply amount. In this embodiment, the relief passage 23 corresponds to the oil discharge passage of the present invention. Further, when the present invention is implemented in such a manner that the jet pump 32 is arranged in the branch passage branched from the oil supply passage 22 as described above and the oil flow in the branch passage is used, the branch passage is the present invention. It corresponds to the oil discharge passage.

(Second form)
Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first embodiment in the configuration of the lubrication device and the oil recovery device provided in the internal combustion engine. Components that are the same as those in the first embodiment are denoted by the same reference numerals in FIG. As shown in FIG. 4, the internal combustion engine 1 is provided with a dry sump type lubricating device 220. The oil pan 205 is smaller in volume than the oil pan 5 in FIG. 1 and is configured to be smaller in size than the oil pan. The lubrication device 220 includes a scavenge pump 26 that pumps oil from the oil pan 205, an oil tank 27 that can store a predetermined amount of oil, an oil discharge passage 28 that connects the scavenge pump 26 and the oil tank 27, and an oil tank. And a feed pump 29 for pumping oil from 27 and supplying the oil to each part of the internal combustion engine 1. The scavenge pump 26 and the feed pump 29 are each driven by a predetermined drive source such as an electric motor or the internal combustion engine 1.

  The oil discharged from the feed pump 29 is guided to the oil supply passage 22 of the internal combustion engine 1. The oil supplied to the cylinder head 4 through the oil supply passage 22 is guided to the oil return passage 24 and is temporarily collected in the oil pan 205. The oil collected in the oil pan 205 is pumped out by the scavenge pump 26 and guided to the oil tank 27 through the oil discharge passage 28. Various devices such as an oil filter for removing foreign substances and a defoamer for removing bubbles are arranged in the discharge passage 28, but the illustration is omitted.

  The oil recovery device 230 is the same as that of the first embodiment except that a jet pump 32 as an oil suction means is provided in the oil discharge passage 28. Therefore, FIG. 3 is referred to for details of the jet pump 32. The jet pump 32 can suck oil in the oil recovery passage 31 using the flow of oil guided to the oil discharge passage 28, and the oil sucked by the jet pump 32 is recovered in the oil tank 27 through the oil discharge passage 28. The In this way, the oil recovery device 230 can exhibit the same effect as that of the first embodiment.

  The present invention is not limited to the above embodiments, and can be implemented in various forms within the scope of the gist of the present invention. The internal combustion engine to which the present invention is applied may be an internal combustion engine that is mounted on a vehicle in a state where an oil return passage that guides oil supplied to the cylinder head to the oil pan intersects the vertical direction. There is no. For example, the present invention can be applied to a horizontally opposed internal combustion engine having a bank angle of 180 °.

  Further, the oil recovery position, that is, the connection position of the oil recovery passage 31 is not limited to being provided in the cylinder head 4, but is provided in the cylinder block 3 as indicated by the imaginary line in FIGS. The oil in the oil return passage 24 may be guided to 31. In this case, the oil reservoir 33 is configured to open to the oil return passage 24.

  In the above embodiment, there is an advantage that the rising speed of the oil level of the oil is reduced by providing the oil reservoir 33, but the oil reservoir 33 is not an essential configuration of the present invention. Accordingly, the oil reservoir 33 may be omitted and the oil recovery passage 31 may be directly connected to the cylinder head 4 or the oil return passage 24 of the cylinder block 3.

  Further, the configuration of the oil suction means is not limited to the above form, and may be realized by a dedicated suction pump using, for example, an electric motor or an internal combustion engine as a drive source. Moreover, you may comprise so that suction operations, such as the amount of oil suction | inhalation by an oil suction means, execution of a suction | stop, and a stop, can be controlled. For example, a control valve (not shown) that opens and closes the oil recovery passage 31 may be provided, and the opening of the valve may be controlled using an engine control unit (ECU) that controls the operating state of the internal combustion engine 1.

BRIEF DESCRIPTION OF THE DRAWINGS The whole block diagram which shows the form which applied the oil collection | recovery apparatus of this invention to the internal combustion engine. Explanatory drawing which showed the internal structure of the cylinder head typically from the A direction of FIG. Explanatory drawing explaining the detail of a jet pump. The whole block diagram concerning the 2nd form of the present invention.

Explanation of symbols

1 Internal combustion engine 4 Cylinder head 5, 205 Oil pan 21 Oil pump 23 Relief passage (oil discharge passage)
24 Oil return passage 26 Scavenge pump 27 Oil tank 28 Oil discharge passage 30 Oil recovery device 31 Oil recovery passage 32 Jet pump (oil suction means)
33 Oil reservoir

Claims (5)

Oil recovery of an internal combustion engine that is applied to an internal combustion engine mounted on a vehicle in a state where an oil return passage for guiding oil supplied to the cylinder head to an oil pan intersects the vertical direction, and recovers the oil supplied to the cylinder head A device,
An oil recovery device for an internal combustion engine, comprising: an oil recovery passage capable of guiding oil in the cylinder head or the oil return passage; and an oil suction means for sucking oil in the oil recovery passage. .   2. The oil recovery apparatus for an internal combustion engine according to claim 1, further comprising an oil reservoir that is connected to the oil recovery passage and can store oil.   The oil recovery apparatus for an internal combustion engine according to claim 2, wherein the oil reservoir is provided in the cylinder head. The internal combustion engine is provided with an oil pump for supplying oil to the cylinder head, and an oil discharge passage that is connected to the oil pump and guides oil discharged from the oil pump,
As the oil suction means, there is provided a jet pump that is provided in the oil discharge passage and is connected to the oil recovery passage and sucks oil in the oil recovery passage by utilizing the oil flow in the oil discharge passage. The oil recovery device for an internal combustion engine according to any one of claims 1 to 3, wherein the oil recovery device is an internal combustion engine. The internal combustion engine is provided with a scavenge pump that draws oil from the oil pan, an oil tank that can store oil, and an oil discharge passage that connects the scavenge pump and the oil tank,
As the oil suction means, a jet that is provided in the oil discharge passage of the lubrication device and is connected to the oil recovery passage and sucks oil in the oil recovery passage using the oil flow in the oil discharge passage The oil recovery apparatus for an internal combustion engine according to any one of claims 1 to 3, wherein a pump is provided.

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