Oil pan of an internal combustion engine

Abstract

To provide an oil pan that can draw up oil without introducing air bubbles. [Solution] The oil pan has an oil pan body 1 and a cover member 2 that is fixed on top of the deepest part 3 of the oil pan. The cover member 2 is a shallow tray shape with an opening facing downward, and an oil suction chamber is formed by the cover member 2 and the recess 17 of the oil pan body 1. Multiple oil suction ports 23a to 23d are formed intermittently in the circumferential direction on the side plate 18 and rear plate 19 of the cover member 2. The opening area of ​​the oil suction ports 23a to 23d becomes larger as they move away from the suction port 15. Since the oil suction ports 23a to 23d are small and independent of each other, the recess 17 is not pulled downward and air is not sucked in. Even if the oil is disturbed by the movement of the car, oil containing air bubbles will not forcefully enter the oil suction chamber.

Description

Technical Field

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[0001] The present invention relates to an oil pan used for an internal combustion engine.

Background Art

[0002] Internal combustion engines such as gasoline engines and diesel engines have an oil pan for storing oil for lubrication and the like as an essential element. In many cases, the oil in the oil pan is sucked up by an oil pump through a cylindrical strainer and sent to each part. In this case, there is a problem that the mounting structure of the strainer becomes complicated.

[0003] On the other hand, an oil suction passage whose lower end opens toward the oil reservoir and whose upper end is connected to the oil pump is also formed in the oil pan body. Regarding such an oil pan integrated with an oil suction passage, Patent Document 1 discloses a structure in which the starting end of the oil suction passage is recessed in the oil pan body, the starting end of the oil suction passage is surrounded from above by a strainer (filter), and further, the strainer is covered with a cover from above, and a gap is provided between the cover and the oil pan body.

[0004] In Patent Document 1, there is an overall gap in the circumferential direction of the cover between the cover and the oil pan body, and oil flows in from the gap below the cover and is sucked up into the oil suction passage through the strainer.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a suction-type system using a cylindrical strainer, the oil is easily drawn downwards along the outer circumference of the strainer. As a result, when the oil level drops to a certain point, air can be drawn into the strainer along with the oil. This can lead to air-mixed oil being sent to lubrication parts and VVTs, causing various problems such as malfunctions, seizure, and vibration.

[0007] When a strainer is used, the oil is pulled downwards because the oil's viscosity causes it to move in a chain reaction. However, in the case of a cylindrical strainer, the oil surrounding the strainer is essentially connected, so the overall downward movement and the resulting dip in the oil level are more pronounced.

[0008] On the other hand, in Patent Document 1, the gap between the cover and the oil pan body extends in a continuous line along the outer circumference of the cover, which makes it easier for the oil surrounding the cover to be pulled downwards in a kind of connected state, and therefore, there is concern about air being drawn in.

[0009] Furthermore, in Patent Document 1, the cover is in the form of a shallow tray with a downward opening, but since it covers the strainer (filter) from above, the top surface of the cover is considerably higher than the bottom surface of the oil pan body. Therefore, if applied to the oil pan of an automobile internal combustion engine, there is a concern that oil containing air may enter the inside of the cover due to the sloshing of the oil caused by the movement of the automobile, causing air pockets to form inside the cover.

[0010] The present invention was made to improve this current situation. [Means for solving the problem]

[0011] The present invention is, "The oil pan body has a deepest part that serves as an oil intake section, and a cover member is placed on top of the deepest part of the oil pan body, and the oil pan body and the cover member form an oil intake chamber having a peripheral wall and an upper lid." The oil pan body has an oil suction passage formed therein, one end of which communicates with the oil suction chamber and the other end of which is connected to the oil pump. In this oil pan, "Multiple oil intake ports for drawing oil in from the side are formed intermittently in the circumferential direction on the peripheral wall of the oil intake chamber." This is the configuration that is being adopted.

[0012] The present invention can be implemented in various ways. For example, in claim 2, "The oil intake chamber has ribs formed therein that cause the oil flowing in from the oil intake port to meander." This is the configuration that is being adopted.

[0013] In the present invention, the oil intake chamber can be formed by the cover member alone, or it can be formed by the cooperation of the cover member and the oil pan body. That is, the cover member can be formed in the shape of a tray with a downward opening, and the inside of the cover member can be made into an oil intake chamber, or an enclosure wall can be provided projecting upward from the oil pan body, and the enclosure wall can be covered with the cover member to form an oil intake chamber. It is also possible to cover the enclosure wall of the oil pan body with a tray-shaped cover member.

[0014] Therefore, the oil intake can be formed in the cover member, or if an enclosure wall is formed on the oil pan body, the oil intake can be formed in the enclosure wall. The oil intake can be in the form of either a hole or a notch.

[0015] The meandering according to claim 2 includes both a vertical meandering mode and a horizontal meandering mode. It is also possible to combine vertical and horizontal meandering. [Effects of the Invention]

[0016] In the present invention, since the oil intake ports are intermittent in the circumferential direction of the oil intake chamber, the oil located at each oil intake port is independent of each other, and the oil is drawn into the intake port in a clean manner. Therefore, the phenomenon of oil being pulled downward at each oil intake port does not occur. Furthermore, since multiple oil intake ports are formed, the required amount of oil can be drawn in.

[0017] Furthermore, in the present invention, since oil intake ports are intermittently formed on the peripheral wall of the oil intake chamber, when applied to the oil pan of an automobile internal combustion engine, even if the oil shakes horizontally (becomes agitated) due to the shaking of the vehicle, it is possible to prevent oil containing air from flowing into the oil intake chamber from the oil intake ports.

[0018] In other words, in the case of Patent Document 1, since there is a gap throughout the entire lower part of the cover, there is a concern that the oil, with its momentum, will flow forcefully into the space below the cover (passing straight through the space below the cover), and that the air contained in the oil flow will stagnate in the space inside the cover. However, in the present invention, since the oil intake port is intermittently connected to the peripheral wall of the oil intake chamber, even if the oil shakes vigorously (rages) in the oil pan body, the oil flow will collide with the peripheral wall of the oil intake chamber, and the oil will not forcefully enter the oil intake chamber from the oil intake port.

[0019] In other words, the oil intake chamber of the present invention exhibits a damping effect that prevents forced inflow by increasing the resistance to the oil intake port as the force of the oil moves turbulently inside the oil pan body, while the suction action to each oil intake port is not affected at all by the turbulence of the oil, thus ensuring accurate oil intake. Therefore, the present invention is suitable as an oil pan for an automobile internal combustion engine where oil turbulence occurs.

[0020] Furthermore, in the invention of the present application, an oil suction chamber is formed by the cover member and the oil pan body. Since the height of the oil suction chamber only needs to be the minimum necessary height, even if the oil collides with the cover member in a wavy state, the upper part of the oil flow containing air will not hit the peripheral wall of the oil suction chamber. Therefore, there is no phenomenon that the oil splashes and air flows into the oil suction chamber. In this regard as well, the invention of the present application is suitable as an oil pan for an automotive internal combustion engine.

[0021] When ribs are provided in the oil suction chamber as in claim 2 to make the oil flow meander, even if air is mixed into the oil, the air can be finely broken by colliding with the ribs and dissolved to a level where the influence of the air as bubbles does not occur.

Brief Description of the Drawings

[0022] [Figure 1] A view showing the first embodiment, (A) is a plan view slightly inclined around the crankshaft axis, and (B) is a plan view of the main part. [Figure 2] (A) is a side sectional view taken along the line IIA-IIA1 of FIG. 1(B), and (B) is a sectional view taken along the line B-B of (A). [Figure 3] A side sectional view of the main part showing the second embodiment corresponding to claim 2. [Figure 4] (A) is a side sectional view of the main part of the third embodiment, (B) is a side sectional view of the main part of the fourth embodiment, (C) is a side sectional view of the main part of the fifth embodiment, (D) is a side sectional view of the main part of the sixth embodiment, (E) is a side sectional view of the main part of the seventh embodiment, (F) is a sectional view taken along the line F-F of (E), (G) is a side sectional view of the main part of the eighth embodiment, and (H) is a sectional view taken along the line H-H of (G). [Figure 5] (A) is a plan view of the main part of the ninth embodiment, (B) is a sectional view taken along the line B-B of (A), and (C) is a side sectional view of the tenth embodiment.

Modes for Carrying Out the Invention

[0023] Next, embodiments of the present invention will be described based on the drawings. This embodiment is applied to the oil pan of an automobile internal combustion engine. In the following, the terms front / rear and left / right will be used to specify directions, where the front / rear direction is the direction of the crank axis, and the left / right direction is the left / right direction perpendicular to the crank axis direction and the cylinder bore axis direction. The front and rear are defined as the side where the timing chain is located and the rear as the side where the transmission case is located.

[0024] (1) Basic structure of the first embodiment Figures 1 and 2 show the first embodiment, with the entire oil pan shown in Figure 1(A). Specifically, Figure 1(A) is a schematic plan view of the oil pan rotated slightly around the crankshaft axis. As can be seen from this figure, the oil pan comprises an oil pan body 1 that opens upward and a synthetic resin cover member 2 that is superimposed and fixed to the deepest part 3 of the oil pan body 1. Although not shown, the oil pan also includes a baffle plate.

[0025] The oil pan body 1 has longitudinal left and right side walls 4, longitudinal left and right front walls 5 and rear walls 6, and a bottom enclosed by these. The bottom consists of shallow bottom sections 7 located on both the left and right sides of approximately the rear half, a deepest section 3 located at the front, and an intermediate bottom section 8 located behind the deepest section 3 and between the left and right shallow bottom sections 7. A pair of boss sections 9 are formed on the inner surface of the left and right side walls 4 at an intermediate height position to fix the baffle plate.

[0026] In Figure 1, parallel diagonal lines are drawn on the upper end surfaces of the peripheral walls 4, 5, and 6 of the oil pan body 1. This is a measure to indicate the upper end surfaces and does not represent a cross-section. The side wall 4 and the rear wall 6 have clusters of tapped holes 10 for fixing to the cylinder block. The front wall 5 and the rear wall 6 also have recesses 11 and 12 to accommodate the crank cap. The timing chain cover is fixed to the front surface of the front wall 5, and the lower half of the transmission case (not shown) is fixed to the rear surface of the rear wall 6.

[0027] In Figure 1, the left side is the intake side and the right side is the exhaust side, and an oil suction passage 14 is formed in the part of the front wall 5 that is closer to the exhaust side. The oil suction passage 14 has a vertically elongated portion 14a whose upper end opens upward from the front wall 5, and horizontally elongated portions 14b that are long on the left and right and communicate with the lower end of the vertically elongated portion 14a. The horizontally elongated portions 14b extend in front of the deepest part 3 and have a suction port 15 that opens toward the deepest part 3. The horizontally elongated portions 14b are formed by passing a drill through the side of the exhaust side, and the opening of the hole formed by the drilling process is sealed with a plug 16 (see Figure 1(B)).

[0028] Although not shown in the diagram, the oil suction passage 14 communicates with an oil suction passage formed in the front wall of the cylinder block, and the oil suction passage communicates with a suction port in the pump chamber where the rotor of the oil pump is located. The oil pump is, for example, a type in which the rotor is directly connected to the crankshaft, in which case a part of the front cover is used as the pump housing.

[0029] It is also possible to use a system in which the oil pump is fixed to the front of the front wall 5 of the oil pan body 1, and the oil pump is driven by a crankshaft via a chain or gear. In this case, the outlet of the oil suction passage 14 is opened to the front of the front wall 5, thereby connecting the oil suction passage 14 to the suction port of the oil pump.

[0030] (2) Cover member and oil suction chamber As shown in Figure 2(A), a recess 17 is formed in the deepest part 3 of the oil pan body 1, which communicates with the suction port 15 of the oil suction passage 14. The recess 17 is formed in a roughly rectangular shape in plan view, with the front-to-back length being the longest. On the other hand, the cover member 2 has left and right side plates 18 and a rear plate 19 that is continuous with them, and a top plate 20 that is continuous from above with respect to these side plates 18 and the rear plate 19, forming a shallow rectangular tray shape that opens downwards, with the side plates 18 and the rear plate 19 fitted into the recess 17 to a depth of about half its length.

[0031] Therefore, the cover member 2 and the recess 17 form an oil suction chamber that opens forward, and the opening at the front end of the oil suction chamber communicates with the suction port 15 of the oil suction passage 14. Furthermore, the left and right side plates 18 of the cover member 2 have first to third oil suction ports 23a to 23c, and the rear plate 19 has one fourth oil suction port 23d.

[0032] Each oil intake port 23a to 23d is a rectangular hole of the same height, but its width W increases as it moves away from the intake port 15, with the oil intake port 23a closest to the intake port 15 being the smallest and the fourth oil intake port furthest away being the largest. Therefore, the opening area of ​​each oil intake port 23a to 23d increases as it moves away from the intake port 15. The lower end of each oil intake port 23a to 23d coincides with the bottom surface of the deepest part 3, and the upper end coincides with the lower end of the top plate 20.

[0033] The upper end of the suction port 15 is higher than the upper ends of the oil intake ports 23a to 23d. As a result, the cover member 2 is taller from the middle to the front, and the front end of the top plate 20 overlaps the horizontally elongated boss 24 on which the suction port 15 is formed. Consequently, the front part of the top plate 20 is a raised section 20a that is taller towards the front. The front ends of the left and right side plates 18 are curved to overlap the horizontally elongated boss 24.

[0034] The left and right side plates 18 of the cover member 2 have left and right flanges 25 that fit into recesses 17, and the left and right flanges 25 are fixed to the oil pan body 1 by bolts 26. The oil pan body 1 has downward-facing bosses 27 to ensure sufficient threading depth for the bolts 26.

[0035] (3) Summary of the first embodiment The first embodiment has the above configuration. Oil is drawn in from each oil intake port 23a to 23d by the operation of the oil pump. However, since each oil intake port 23a to 23d is small and independent of each other, the phenomenon of the oil surrounding the cover member 2 being pulled downward in a tailgating manner does not occur, and the oil is drawn into each intake port 15 by crawling along the bottom surface of the deepest part 3. In other words, the oil is drawn into each oil intake port 23a to 23d in a clean manner. Therefore, the phenomenon of air on the oil surface being pulled downward and air bubbles mixing with the oil does not occur.

[0036] Although the opening area of ​​each individual oil intake port 23a to 23d is small, the sum of the opening areas of each oil intake port 23a to 23d is set to the area required for oil intake, so that the engine can be supplied with the necessary oil. The oil suction force inside the oil intake chamber decreases as you move away from the suction port 15, but in this embodiment, the opening area of ​​the oil intake ports 23a to 23d increases as you move away from the suction port 15, so that the amount of oil sucked in from each oil intake port 23a to 23d is equalized and the inflow resistance is suppressed.

[0037] Furthermore, since the oil flowing down from the cylinder head flows into the oil pan body 1 via the oil drain passage, variations in oil temperature may occur at the deepest part 3 of the oil pan body 1 during startup. However, in this embodiment, by equalizing the amount of oil flowing in from each oil intake port 23a to 23d, the oil that flows down to the deepest part 3 is mixed in the oil intake chamber, contributing to the equalization of oil temperature.

[0038] Furthermore, although the oil may slosh around inside the oil pan body 1 due to the vehicle starting, stopping, and turning, the flow resistance at the oil intake ports 23a to 23d increases as the oil flow velocity increases, so the phenomenon of oil containing air bubbles being forcefully drawn into the oil intake chamber does not occur. Therefore, it is also possible to prevent air bubbles from mixing into the oil due to the vehicle's movement. As shown by the dashed line in Figure 2, forming an outward-facing projection 20b on the top plate 20 can reliably prevent the oil from being pulled downwards (however, it may be better not to have the outward-facing projection 20b in order to allow air bubbles mixed in the oil to escape).

[0039] As in the embodiment, by forming a recess 17 in the deepest part 3 and fitting the cover member 2 therein, the volume of the oil intake chamber can be increased while positioning each oil intake port 23a to 23d at a lower level, thereby reducing flow resistance while preventing air from entering. It is also possible to place a filter at the front end of the oil intake chamber or at the lower horizontal section 14b of the oil intake passage 14.

[0040] (4) Other embodiments Figure 3 shows a second embodiment. This embodiment is a specific example of claim 2, and, based on the first embodiment, downward ribs 30 and upward ribs 31 are alternately provided in the front-rear direction on the cover member 2 and the recess 17, thereby forming a labyrinth structure inside the oil suction chamber in which the oil flows in a meandering manner up and down. In this embodiment, if air bubbles are mixed in the oil, it is possible to crush the air bubbles finely and prevent vaporization.

[0041] As shown by the dashed line, it is also possible to form multiple narrow slits 32 side by side on the underside of the raised portion 20a of the top plate 20, and open the group of slits 32 forward. In this case, it becomes possible to collect air bubbles in the slits 32 and release them upward.

[0042] In this case, the suction port 15 opens backward and the suction force acts from back to front, while the front end of the slit 32 is located in front of the suction port 15. Therefore, the oil sucked in from each oil suction port 23a to 23d flows into the suction port 15 with a strong forward direction, so the oil is not sucked downward from the slit 32, and the air bubbles collected in the slit 32 are pushed out by the oil and discharged from the oil suction chamber (because the cross-sectional area of ​​the slit 32 is small and the oil flows directionally towards the suction port 15, the oil does not escape forward from the slit 32).

[0043] In the third embodiment shown in Figure 4(A), the recess 17 is not formed in the deepest part 3, and the oil intake ports 23a to 23d are formed by creating downward-facing notches in the side plate 18 and rear plate 19 of the cover member 2. Even when the recess 17 is provided as in the first embodiment, the notched type oil intake ports 23a to 23d can be formed.

[0044] In the fourth embodiment shown in Figure (B), when a recess 17 is formed in the deepest part 3 of the oil pan body 1, the cover member 2 is set to overlap the outside of the recess 17, and oil intake ports 23a to 23d are cut out in the deepest part 3 and communicate with the recess 17. In other words, in this embodiment, the oil intake ports 23a to 23d are formed in the deepest part 3 of the oil pan body 1.

[0045] In the fifth embodiment shown in Figure 4(C), no recess 17 is formed in the deepest part 3 of the oil pan body 1. When notched oil intake ports 23 are formed in the side plate 18 and the rear plate 19, a flange 33 is formed on the cover member 2 so as to protrude from the top plate 20, and the flange 33 is fixed to a boss 34 protruding from the deepest part 3 with bolts 26. The flange 33 may be formed only at the location of the boss 34, or it may be formed around the entire circumference of the top plate 20.

[0046] In the sixth embodiment shown in Figure 4(D), a recess 17 is formed in the side plate 18 of the oil pan body 1 and the cover member 2 is fitted into this recess 17. A single boss 34 is provided protruding upward from the inside of the recess 17, and the top plate 20 of the cover member 2 is fixed to the boss 34 with a bolt 26. Since the cover member 2 is positioned in a way that prevents it from shifting within the recess 17, the cover member 2 is firmly fixed with only one bolt 26.

[0047] In the seventh embodiment shown in Figures 4(E) and 4(F), an upward-facing enclosure frame 35, such as a U-shape in plan view, is formed in the deepest part 3 of the oil pan body 1, and the cover member 2 is fitted into the enclosure frame 35 to form an oil suction chamber. In this embodiment, the lower half of the enclosure frame 35 is exposed to the side, and an upward-facing notch is formed in the enclosure frame 35 to form an oil suction port 23. The method of fixing the cover member 2 is the same as in the sixth embodiment.

[0048] In the eighth embodiment shown in Figures 4(G) and 4(H), an enclosure frame 35 is provided protruding from the side plate 18 of the oil pan body 1 and is covered from above with a cover member 2. In this example, the lower surface of the cover member 2 is brought into contact with the deepest part 3, and a flow path for oil is formed between the outer surface of the enclosure frame 35 and the inner surface of the cover member 2. Notched oil intake ports 23 are also formed in the cover member 2 and the enclosure frame 35. By offsetting the oil intake ports 23 of the cover member 2 and the oil intake ports 23 of the enclosure frame 35 in the circumferential direction, a labyrinth structure is created in which the oil flow path meanders in plan view.

[0049] A flange (not shown) is provided protruding from the top plate 20 of the cover member 2, and the flange is fixed to a boss (not shown) of the oil pan body 1 with a bolt (not shown). This embodiment can also be applied to structures having a recess 17.

[0050] In the ninth embodiment shown in Figures 5(A) and 5(B), the cover member 2 is formed in a circular shape in plan view, with a passage portion 36 extending radially formed in a part thereof, and the passage portion 36 is connected to the lower horizontal portion 14b of the oil suction passage 14. The oil suction passage 14 is located near the corner portion of the oil pan body 1, and the lower horizontal portion 14b of the oil suction passage 14 and the passage portion 36 of the cover member 2 are inclined in the same direction as the diagonal direction of the oil pan body 1 in plan view.

[0051] Multiple oil intake ports 23 are formed intermittently in the circumferential direction on the peripheral wall 37 of the cover member 2. The passage portion 36 has a trough-like shape that opens downward, and its front end is fitted into the lower horizontal portion 14b of the oil suction passage 14.

[0052] In the tenth embodiment shown in Figure 5(C), the cover member 2 is formed in a circular shape and the peripheral wall 37 forms a complete annular shape. The passage portion 36 is formed in an L shape with an upward-facing portion 36a located in the center of the cover member 2 and a horizontal portion 36b extending radially from the upward-facing portion 36a, with the front end of the horizontal portion 36b fitted into the suction port 15. The upper half of the passage portion 36 is made of a separate material and is welded to the main body. In this embodiment, the oil suction passage 14 is made of a vertically elongated portion 14a, and the suction port 15 is formed at the lower end of the vertically elongated portion 14a.

[0053] In this embodiment, the peripheral wall 37 of the cover member 2 is perfectly circular, and the oil intake port 23 is of the notched type. Since the upward portion 36a of the passage portion 36 is located at the center of the cover member 2, oil flows into the oil intake chamber from all sides. Therefore, each oil intake port 23 is the same size.

[0054] Although embodiments of the present invention have been described above, the present invention can be implemented in various other ways. For example, the plan view shape of the cover member can be various forms such as polygons or ovals. The shape of the oil intake port does not have to be square, and circular or triangular shapes can also be used. [Industrial applicability]

[0055] The present invention can be implemented in the oil pan of an internal combustion engine. Therefore, it can be used industrially. [Explanation of Symbols]

[0056] 1. Oil pan body 2 Cover member 3. The deepest part of the oil pan body 4. Side walls of the oil pan body 5 Front wall 6. Back wall 7 Shallow bottom 14 Oil suction passage 14a Vertical section 14b Lower oblong part 15 Suction port 17 Recess 18 Side panel 19 Rear plate 20 top plate 23, 23a~23d Oil intake port 25 Flange 26 volts 35 Enclosure Frame

Claims

1. The oil pan has a deepest part that serves as an oil intake section, and a cover member is placed on top of the deepest part of the oil pan body. The oil pan body and the cover member form an oil intake chamber having a peripheral wall and an upper lid. The oil pan body has an oil suction passage formed therein, one end of which communicates with the oil suction chamber and the other end which is connected to the oil pump, Multiple oil intake ports for drawing oil in from the side are formed intermittently in the circumferential direction on the peripheral wall of the oil intake chamber. Oil pan for an internal combustion engine.

2. The oil intake chamber has ribs formed therein that cause the oil flowing in from the oil intake port to meander. An oil pan for an internal combustion engine as described in claim 1.

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