JP2004251199A - Oil return device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil return device capable of preventing generation of bubbles in engine oil. <P>SOLUTION: This oil return device comprises an upper opening 44 being opened upward; a lower opening 46 being opened downward; a partition plate 47 provided between the upper opening 44 and the lower opening 46 and having a small hole. The oil return device is near a timing chain 33 of an internal combustion engine, and is installed on the lower side of sprockets 31, 32 installed on the most upper side of the sprockets 31, 32, 37 engaged with the timing chain 33. Thus, the oil dropping from the upper side of the internal combustion engine enters from the upper opening 44 and hits the partition plate 47. Falling velocity of the oil can be lowered, thus the bubbles generated in the oil can be reduced more than in the case there is no the oil return device. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an oil return device that forms a part of a circulation path for engine oil.
[0002]
[Prior art]
2. Description of the Related Art Generally, in an internal combustion engine used for an automobile or the like, an oil pump pumps engine oil (hereinafter, referred to as "oil") stored in an oil pan to each part to lubricate and cool sliding parts and rolling parts. At the same time, various hydraulic operating devices are operating. In particular, in an internal combustion engine having a variable valve timing mechanism, a valve lash adjuster, or the like, a large amount of oil is supplied to a cylinder head, that is, a lubrication and cooling of cam peripheral members, and an oil supply to these hydraulically operated devices. It is supplied to the upper side of the internal combustion engine.
[0003]
The oil supplied to the upper side of the internal combustion engine in this way falls into an oil pan through a lubricating oil return passage formed in a cylinder block or the like, or through a timing chain side of the internal combustion engine, and is dropped by an oil pump. (For example, Patent Document 1 discloses a lubrication system formed by penetrating from the lower end surface of the cylinder block to the upper surface of the cylinder head so as to smoothly drop the oil of the cylinder head onto the oil pan. An oil return passage is disclosed.)
[0004]
Here, if the oil falls from the timing chain side of the internal combustion engine, the following problem may occur. That is, since a large amount of oil vigorously falls from the upper side of the internal combustion engine to the oil pan, bubbles may be generated in the oil, and the bubble ratio of the oil may increase. In addition, if the timing chain or rotating sprocket is moving randomly and vigorously while the oil is falling, the oil will be scattered, which will also increase the oil bubble rate. Is concerned.
[0005]
When the bubble rate of oil increases, the amount of oil used for lubrication and cooling may be smaller than intended, and various hydraulic operating devices (for example, a variable valve timing mechanism) And chain tensioners) may be impaired.
[0006]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-53432 [Patent Document 2]
JP-A-9-86200 [Problems to be Solved by the Invention]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an oil return device that can suppress generation of bubbles in engine oil.
[0007]
[Means for Solving the Problems]
The present invention provides an oil return device described in each claim as means for solving the above problems.
A first invention provides an oil having an upper opening that opens upward, a lower opening that opens downward, and a partition plate provided between the upper opening and the lower opening and having a small hole. An oil return device provided near the timing chain of the internal combustion engine and located below the uppermost sprocket of the sprockets engaged with the timing chain.
[0008]
According to the present invention, the oil that falls from the upper side of the internal combustion engine enters the oil return device from the upper opening and hits the partition plate, and then passes through the small holes provided in the partition plate, and It falls down from the opening and finally returns to the oil pan. As described above, according to the present invention, the oil falling from the upper side of the internal combustion engine hits the partition plate. However, the oil falling speed is reduced by this, so that compared with the case where the present oil return device is not provided. Thus, air bubbles generated in the oil can be reduced. That is, according to the present invention, generation of bubbles in engine oil can be suppressed.
[0009]
In a second aspect based on the first aspect, the lower opening has a smaller opening area than the upper opening.
According to the present invention, since the lower opening has an opening area smaller than that of the upper opening, the oil entering from the upper opening is accumulated in the oil return device and moves downward from a predetermined lower opening position. It will fall and eventually return to the oil pan. By doing so, it is possible to reduce bubbles generated in the oil as compared with a case where the oil drops randomly from above the internal combustion engine.
[0010]
In a third aspect based on the first or second aspect, the oil return device is installed above a sprocket other than the sprocket provided at the uppermost side among sprockets engaged with the timing chain of the internal combustion engine.
According to the present invention, since the present oil return device is installed above a sprocket other than the above-described sprocket provided at the uppermost side (hereinafter, referred to as “lower sprocket”), the oil that has entered the oil return device Can be supplied to the lower sprocket. In particular, if the area of the lower opening is made small and the position becomes a preferable position for lubricating the lower sprocket and the timing chain, these can be efficiently lubricated. Thereby, for example, it is possible to reduce or cancel the oil jet for the timing chain.
[0011]
In a fourth aspect based on the third aspect, an oil supply port connected to oil supply means is provided on a side wall extending from the upper opening to the lower opening. Oil is supplied.
According to the present invention, oil is supplied through the oil supply port when the amount of oil dropped at the time of starting, for example, is not sufficient to lubricate the lower sprocket and the timing chain. As a result, the lower sprocket and the timing chain can always be sufficiently lubricated.
[0012]
In a fifth aspect based on any one of the first to fourth aspects, the partition plate has a plurality of the partition plates, and the positions of the small holes of the partition plate are different from each other.
According to the present invention, since the falling oil almost certainly hits the partition plate, the falling speed of the oil can be reduced more reliably. This makes it possible to more reliably reduce bubbles generated in the oil.
[0013]
In a sixth aspect based on any of the first to fifth aspects, the partition plate has a plurality of the small holes.
The total area of the small holes provided in the partition plate is related to the amount of oil passing through the partition plate and needs to have a substantially predetermined value. In this case, the area of each small hole can be reduced by increasing the number of the small holes. Therefore, according to the present invention, the area of each small hole is reduced, so that the falling oil hits the partition plate more reliably, and the oil falling speed can be more reliably reduced. It can be aimed at. This makes it possible to more reliably reduce bubbles generated in the oil.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or similar components are denoted by common reference numerals.
FIG. 1 is a schematic perspective view showing an internal structure of an internal combustion engine to which an embodiment of an oil return device of the present invention is applied, and an oil circulation path is indicated by an arrow. In the figure, 7 is a crankshaft, 9 is a piston, 11 is a roller rocker arm, 17 is an intake valve, and 19 is an exhaust valve. 23 is a cam for opening and closing the intake valve, 25 is a cam for opening and closing the exhaust valve, 13 is a cam shaft that carries the intake valve cam 23, and 15 is a cam that carries the exhaust valve cam 25. Camshaft.
[0015]
Reference numeral 33 denotes a timing chain. The timing chain 33 includes a lower sprocket 37 attached to the crankshaft 7, a sprocket 32 attached to the camshaft 13, and a sprocket 31 attached to the camshaft 15. Engaged and wrapped around them. Reference numeral 35 denotes a chain tensioner for the timing chain 33, which is hydraulically operated.
[0016]
Further, the internal combustion engine shown in FIG. 1 has a variable valve timing mechanism 27 for shifting the opening / closing timing of the intake valve 17. In other words, by operating the variable valve timing mechanism 27, the opening / closing timing of the intake valve 17 can be shifted to the advanced side or the retarded side, thereby adjusting the valve overlap amount and the like. It can be carried out. The variable valve timing mechanism 27 is operated by hydraulic pressure, and 29 is an oil control valve that controls the hydraulic pressure for operating the variable valve timing mechanism 27.
[0017]
Here, the operation of the variable valve timing mechanism 27 will be briefly described with reference to FIG. That is, in FIG. 2, reference numeral 41 denotes an advance-side oil passage for shifting the opening / closing timing of the intake valve 17 to the advance side, and reference numeral 43 denotes a retard-side oil for shifting the opening / closing timing of the intake valve 17 to the retard side. The road 3 is an oil pump, and 5 is an oil pan. As the oil pressure in the advance side oil passage 41 increases, the opening / closing timing of the intake valve 17 is shifted to the advance side. That is, the rotation phase of the camshaft 13 with respect to the crankshaft 7 is advanced. On the other hand, as the oil pressure in the retard side oil passage 43 increases, the opening / closing timing of the intake valve 17 is shifted to the retard side. That is, the rotation phase of the camshaft 13 with respect to the crankshaft 7 is retarded.
[0018]
The variable valve timing mechanism 27 is operated by controlling the oil pressure in the advance side oil passage 41 and the oil pressure in the retard side oil passage 43 by the oil control valve 29 in this manner. As can be seen from the above description and FIG. 1, it can be said that the above-described sprocket 32 is a sprocket provided in the variable valve timing mechanism 27.
[0019]
Returning to FIG. 1, oil is pumped up from an oil pan 5 by an oil pump 3 as shown by an arrow, and is supplied to various parts such as a crankshaft 7, a piston 9, and camshafts 13 and 15. Oil is supplied to the cams 23 and 25, the roller rocker arm 11, and the surrounding area via the cam shower 21. The oil is also supplied to the oil control valve 29, the chain tensioner 35, and the like.
[0020]
Of the oil supplied to each part as described above, most of the oil supplied to the upper side of the internal combustion engine (for example, the variable valve timing mechanism 27, the cam shower 21, the oil control valve 29, etc.) and the chain tensioner 35 is a timing chain. Although it falls from the side 33 and finally returns to the oil pan 5, in the internal combustion engine shown in FIG. 1, the oil return member 39 is placed near the timing chain 33 where a large amount of oil falls. Has been installed.
[0021]
FIG. 3 is a schematic explanatory diagram when the internal combustion engine shown in FIG. 1 is viewed from the timing chain 33 side. As shown in FIG. 3, more specifically, in the internal combustion engine shown in FIG. 1, the oil return member 39 is located below the sprockets 31 and 32 and above the lower sprocket 37. At the position, that is, in a space surrounded by the timing chain 33, the sprockets 31, 32, and the lower sprocket 37, the mounting tab 50 is attached to the outer wall surface 51 of the cylinder block by screwing (screw not shown). Thus, the oil return member 39 constitutes an oil return device together with the outer wall surface 51 of the cylinder block.
[0022]
FIGS. 4A and 4B are explanatory views showing the oil return device of the present embodiment in further detail. FIG. 4A shows a top view, and FIG. 4B shows a front view. As shown in FIG. 4, the oil return device of the present embodiment has an upper opening 44 that opens vertically upward and a lower opening 46 that opens downward and has an opening area smaller than the upper opening. ing.
[0023]
The oil return member 39 constituting the present oil return device has three partition plates 47 between the upper opening 44 and the lower opening 46. Each partition plate 47 has a plurality of small holes 49. The positions of these small holes 49 are provided to be different from each other in each partition plate 47 when viewed from above. Further, an oil supply port 45 connected to an electric oil pump and capable of supplying oil as required is provided in a portion of the outer wall surface 51 of the cylinder block which constitutes a side wall of the present oil return device. ing.
[0024]
In the internal combustion engine shown in FIG. 1 having the oil return device configured as described above, it is possible to reduce bubbles generated in the oil and to avoid various inconveniences caused by an increase in the bubble ratio of the oil. Can be.
That is, conventionally, when oil falls from the timing chain 33 side of the internal combustion engine, a large amount of oil vigorously falls into the oil pan 5 from the upper side of the internal combustion engine, so that bubbles are generated in the oil, and the bubble rate of the oil is reduced. May rise. If the timing chain 33 and the rotating sprocket 37 are moving randomly and violently while the oil is falling, the oil will scatter and the oil bubble rate will also increase. there's a possibility that.
[0025]
When the bubble rate of oil increases, the amount of oil used for lubrication and cooling may be smaller than intended, and the oil pressure may decrease due to a decrease in oil pressure, such as the variable valve timing mechanism 27 or the chain tensioner 35. The operability and responsiveness of the operating device may be impaired.
On the other hand, in the internal combustion engine shown in FIG. 1, the oil return device having the above-described configuration is installed below the upper sprockets 31 and 32. After entering the oil return device from the upper opening 44 and hitting the partition plate 47, it then passes through the small holes 49 provided in each of the partition plates 47, falls downward from the lower opening 46, and finally reaches the oil pan. It will return to 5. That is, the oil falling from the upper side of the internal combustion engine hits the partition plate 47, thereby reducing the falling speed of the oil and reducing bubbles generated in the oil as compared with the case without the oil return device. can do.
[0026]
In particular, the oil return device of the present embodiment has the above-mentioned three partition plates 47, and each partition plate 47 has a plurality of small holes 49 which are different from each other when the position is viewed from above. It is provided. In the oil return device of the present embodiment, by doing so, the amount of oil that flows through each partition plate 47 through the small holes 49 and passes through the partition plate 47 is ensured, and the falling oil is surely removed from the partition plate 47. Is to hit.
[0027]
That is, for example, if the number of the partition plates 47 is one, the possibility that the oil falls through the small holes 49 without hitting the partition plates 47 increases. Further, for example, when the number of the small holes 49 is one and the opening area of the one small hole 49 is increased in order to secure the amount of oil flowing through the partition plate 47, the small Even when the size of the coming oil droplets (oil droplets) is large, the oil may drop without hitting the partition plate 47.
[0028]
Therefore, by providing a plurality of partition plates 47 having a plurality of small holes 49 as in the oil return device of the present embodiment, it is possible to more reliably hit the falling oil against the partition plate 47. it can. Further, in the oil return device of the present embodiment, the plurality of small holes 49 provided in each partition plate 47 are arranged so as to be different from each other in each partition plate 47 when viewed from above. Will almost certainly hit the partition plate 47.
[0029]
As described above, in the oil return device of the present embodiment, the falling oil is almost surely brought into contact with the partition plate 47, so that the falling speed of the oil can be reduced more reliably. This makes it possible to more reliably reduce bubbles generated in the oil.
In the oil return device of the present embodiment, the lower opening 46 has an opening area smaller than that of the upper opening 44. With this configuration, the oil that has entered through the upper opening 44 is accumulated in the oil return device and discharged downward as if poured from the lower opening, whereby the oil is discharged from the upper side of the internal combustion engine. Air bubbles generated in the oil can be reduced as compared with the case where the oil drops randomly and vigorously.
[0030]
In particular, in the case of the oil return device of the present embodiment, as shown in FIG. 3, the oil return device is located above the lower sprocket 37, and the lower opening 46 is located in the lower sprocket 37. The timing chain 33 is installed so as to be located above a portion where the timing chain 33 is wound. With such a configuration, most of the oil poured out from the lower opening 46 of the present oil return device is supplied to the portion of the lower sprocket 37 where the timing chain 33 is wound, and the lower sprocket 37 And the timing chain 33 can be efficiently lubricated. Thus, for example, it is possible to reduce or cancel the oil jet for the timing chain.
[0031]
Further, in the oil return device according to the present embodiment, the portion of the outer wall surface 51 of the cylinder block constituting the side wall portion of the oil return device is connected to the electric oil pump and can supply oil as needed. A possible oil supply port 45 is provided. Accordingly, for example, when the amount of oil that falls at the time of starting or the like is not sufficient to lubricate the lower sprocket 37 and the timing chain 33, the oil can be supplied through the oil supply port 45. . Thus, the lower sprocket 37 and the timing chain 33 can always be sufficiently lubricated.
[0032]
As described above, in the case of the oil return device of the present embodiment, most of the oil impinges on the lower sprocket 37 and the timing chain 33. In this case, too, the oil is accumulated and the falling speed of the oil is reduced. Is reduced, the bubble ratio of the oil is reduced as compared with the case where the oil randomly and vigorously collides with the lower sprocket 37 and the timing chain 33. Also, in the present oil return device, part of the oil poured out from the lower opening 46 directly falls into the oil pan 5, but in this case, the oil falling speed is reduced as described above. As a result, the bubble rate of the oil is reduced as compared with the case where the oil drops from the upper side of the internal combustion engine to the oil pan with vigor.
[0033]
As described above, according to the oil return device of the present embodiment, it is possible to suppress the generation of bubbles in engine oil.
Note that, needless to say, the present invention is not limited to the present embodiment. If at least the falling speed of the engine oil can be reduced and generation of bubbles in the oil can be suppressed, the present invention is not limited to this embodiment. It is not necessary to have all of the configurations included. That is, for example, the number of the partition plates 47 does not need to be three, and the lower opening 46 does not have to have an opening area smaller than the upper opening 44.
[0034]
【The invention's effect】
The invention described in each claim has a common effect that generation of bubbles in engine oil can be suppressed.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing an internal structure of an internal combustion engine to which an embodiment of an oil return device according to the present invention is applied, and an oil circulation path is indicated by an arrow.
FIG. 2 is a diagram for explaining an operation of the variable valve timing mechanism shown in FIG. 1;
FIG. 3 is a schematic explanatory view when the internal combustion engine shown in FIG. 1 is viewed from a timing chain side.
FIG. 4 is an explanatory view showing the oil return device shown in FIG. 3 in further detail; FIG. 4 (a) shows a top view, and FIG. 4 (b) shows a front view. .
[Explanation of symbols]
3 Oil pump 5 Oil pan 7 Crankshaft 9 Piston 11 Roller rocker arms 13 and 15 Camshaft 17 Intake valve 19 Exhaust valve 21 Cam shower 23 and 25 Cam 27 Variable valve timing mechanism 29 ... Oil control valves 31, 32 ... Sprocket 33 ... Timing chain 35 ... Chain tensioner 37 ... Lower sprocket 39 ... Oil return member 44 ... Top opening 45 ... Oil supply port 46 ... Bottom opening 47 ... Partition plate 49 ... Small hole 51 ... Cylinder block outer wall

Claims (6)

An oil return device comprising: an upper opening that opens upward, a lower opening that opens downward, and a partition plate that has a small hole provided between the upper opening and the lower opening, An oil return device installed near the timing chain of the internal combustion engine and below the uppermost sprocket among the sprockets engaged with the timing chain. The oil return device according to claim 1, wherein the lower opening has an opening area smaller than the upper opening. 3. The oil return device according to claim 1, wherein the oil return device is installed above a sprocket other than the sprocket provided at the uppermost side among sprockets engaged with a timing chain of the internal combustion engine. 4. 4. An oil supply port connected to oil supply means is provided on a side wall portion extending from the upper opening to the lower opening, and oil is supplied as needed from the oil supply port. The described oil return device. The oil return device according to any one of claims 1 to 4, comprising a plurality of the partition plates, wherein the positions of the small holes of the partition plates are different from each other in the partition plates. The oil return device according to any one of claims 1 to 5, wherein the partition plate has a plurality of the small holes.

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