Oil pan

Abstract

To effectively reduce film vibration of an oil pan without inhibiting flowing of lubrication oil in the oil pan for an internal combustion engine.SOLUTION: A first projecting member 14 extending in a first direction from a side opposite to an oil suction port toward the oil suction port and a hemispherical second projecting member 15 provided in a compartment region partitioned on a bottom surface 11a by the first projecting member 14 are formed on the bottom surface 11a of an oil pan. The height of the second projecting member 15 is lower than that of the first projecting member 14. Since the first projecting member 14 extends in a direction of guiding lubrication oil to the oil suction port and the second projecting member 15 has a hemispherical shape with a rounded surface, flowing of the lubrication oil is not inhibited. In addition to the first projecting member 14, provision of the hemispherical second projecting member 15 in which the whole circumference of a boundary with the bottom surface 11a exhibits an action like a rib enhances rigidity of the bottom surface 11a and reinforces a vibration damping effect.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an oil pan disposed below an internal combustion engine. More particularly, the present invention relates to an oil pan in which membrane vibration is effectively reduced. [Background technology]

[0002] One of the major causes of noise generated from a vehicle is the sound radiated by the vibratory force of the internal combustion engine. An oil pan is placed below the internal combustion engine to catch the lubricating oil dripping from the engine. The sound emitted from below the internal combustion engine is said to be caused by membrane vibration (resonance) of the oil pan at approximately 1 kHz to 3.2 kHz. Vibrations and noises in this frequency band are highly sensitive to the human ear and are very harsh to the ear, so reducing the membrane vibration of the oil pan leads to a significant reduction in vehicle noise.

[0003] In order to reduce such membrane vibration, attempts have been made to reduce membrane vibration by providing long, thin protruding members (ribs) on the bottom surface of the oil pan, as in Patent Document 1, thereby increasing the rigidity of the bottom surface.

[0004] However, merely providing this type of rib-like protruding member is not enough to achieve a sufficient vibration damping effect, even if the frequency band is shifted to a certain extent. Furthermore, depending on the manner in which the rib-like protruding members are installed, they may block the lubricating oil on the oil pan, hindering the flow of lubricating oil to the oil pump or causing the entire amount of lubricating oil to not be drained when it is replaced. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-132537 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, an object of the present invention is to effectively reduce membrane vibration in an oil pan without interfering with the flow of lubricating oil. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the oil pan according to the present invention is provided with a hemispherical convex member on the bottom surface thereof.

[0008] More specifically, the oil pan of the invention comprises a bottom surface, a side surface extending upward from the edge of the bottom surface, and an oil intake port disposed within the oil pan for drawing in lubricating oil dripping from the internal combustion engine, the bottom surface having a first protruding member protruding upward from the bottom surface extending in a first direction, which is the direction from the opposite side of the oil intake port toward the oil intake port, and a second protruding hemispherical protruding member provided in at least one of the partitioned areas on the bottom surface separated by the first protruding member and the side surface, the second protruding member being shorter in height than the first protruding member.

[0009] With this configuration, the first protruding member extends in a direction that guides the lubricating oil on the oil pan to the oil intake port of the oil pump, so it does not significantly impede the flow of lubricating oil.Furthermore, the second protruding member has a hemispherical, rounded surface and is low in height, so it does not significantly impede the flow of lubricating oil.

[0010] The provision of the second protruding member in addition to the first protruding member increases the rigidity of the bottom surface of the oil pan and enhances the vibration damping effect. By providing the second protruding member, the number of first protruding members, which can create resistance even though they are aligned with the oil flow, can be reduced. In particular, in this case, the second protruding member is hemispherical, and the entire circumference corresponding to the boundary with the flat bottom surface acts like a rib, so that the length as a rib can be effectively increased compared to its size, resulting in an even greater vibration damping effect. Furthermore, since the entire circumference of the second protruding member acts like a rib, the area in which the membrane vibrates is narrowed, and therefore the mass of that area is reduced, allowing the membrane vibration to be made higher in frequency than the harsh range of 1 kHz to 3.2 kHz. The boundary between the second protruding member and the bottom surface is rounded in plan view, and there are no corners that could concentrate stress, which prevents stress from concentrating at a specific point on the bottom surface of the oil pan.

[0011] In the oil pan according to the present invention, it is preferable that the second protruding member is convex on the front side of the bottom surface and concave on the rear side of the bottom surface, and forms part of the bottom surface.

[0012] With this configuration, the second protruding member is formed by protruding part of the bottom surface of the oil pan upward, and therefore can be easily manufactured by press working or the like. Furthermore, since the thickness of the second protruding member is not increased, an increase in the weight of the oil pan is prevented. Furthermore, since the thickness of the second protruding member is the same as that of other parts of the bottom surface and the surface area of ​​its front and back surfaces is large, heat dissipation is ensured and the oil pan is prevented from becoming too hot locally.

[0013] In the oil pan of the present invention, it is preferable that the center of the hemispherical surface of the second protrusion member is located in a position offset from the membrane vibration center before the second protrusion member is installed in the partitioned area in which the second protrusion member is installed.

[0014] When configured in this manner, the boundary between the bottom surface and the circumference of the second protruding member acts like a rib, and the area with the highest vibration-damping effect is likely to overlap with the center of membrane vibration, allowing the vibration-damping effect of the second protruding member to be effectively exerted.

[0015] In the oil pan according to the present invention, it is preferable that the second protruding member has an elliptical shape in a plan view with the major axis extending in the first direction.

[0016] With this configuration, the direction that is approximately perpendicular to the first direction, which is roughly the flow direction of the lubricating oil, is the minor axis direction of the second protruding member, which is elliptical in plan view, and is short, so the resistance of the second protruding member to the flow of lubricating oil can be reduced.

[0017] In the oil pan of the present invention, the bottom surface may further include a third protruding member that extends along a first direction and a second direction perpendicular to the first direction and protrudes upward, and the third protruding member may be shorter in height than the first protruding member, and a portion of the third protruding member may be covered by the hemispherical surface of the second protruding member.

[0018] With this configuration, since the third protruding member is provided in addition to the first and second protruding members, the rigidity of the bottom surface of the oil pan is further increased, further enhancing the vibration damping effect. The direction in which the third protruding member extends is different from the first direction that guides the lubricating oil to the oil intake port, so it may hinder the flow of the lubricating oil, but because its height is lower than that of the first protruding member, resistance is reduced. Furthermore, because the third protruding member is covered by the hemispherical surface of the second protruding member where it joins the third protruding member, the lubricating oil can easily pass over the third protruding member along its rounded surface, improving the flow of lubricating oil near the third protruding member. [Effects of the Invention]

[0019] The oil pan according to the present invention is configured as described above, so that it is possible to effectively reduce membrane vibration without impeding the flow of lubricating oil. [Brief explanation of the drawings]

[0020] [Figure 1] Perspective view of the upper oil pan [Figure 2] Enlarged plan view of the upper oil pan [Figure 3] Enlarged vertical cross-sectional view of the upper oil pan [Figure 4](a) is a plan view of the second protruding member, and (b) is a side view of the second protruding member. [Figure 5] Perspective view of the lower oil pan [Figure 6] Cross section of Figure 5 DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The oil pan 10 of the embodiment shown in FIGS. 1 to 6 is attached liquid-tight to the bottom of a cylinder block of an internal combustion engine, and is used to support lubricating oil dripping from the cylinder block.

[0022] The oil pan 10 consists of an upper oil pan body 11 shown in Figures 1 to 3 and a lower tank 12 shown in Figures 5 and 6, with the oil pan body 11 forming the shallow bottom and the tank 12 forming the deep bottom. An oil pump oil intake port (oil strainer) 13 is arranged in the tank 12, and the lubricating oil stored therein is recovered from the oil intake port 13 and used again to lubricate the cylinder block. The lubricating oil in the oil pan 10 can be discharged to the outside through an oil drain hole formed in the bottom surface of the tank 12.

[0023] As shown in Figures 1 to 3, the oil pan body 11 has a generally rectangular and flat bottom surface 11a, front, rear, left and right side surfaces 11b that rise upward from the periphery of the bottom surface 11a, and flanges 11c that protrude outward from the upper edges of the side surfaces 11b, and the entire body is bowl-shaped to easily receive lubricating oil. This flange 11c is fixed to the cylinder block in a liquid-tight manner via packing etc. Fixing is performed by an appropriate means such as screw fastening. In the case of screw fastening, bolt holes 11g are formed in the flange 11c as shown in Figure 2. An opening 11d is formed in the bottom surface 11a of the oil pan body 11 at a position corresponding to one corner in a first direction, which will be described later, and the tank 12 is located below this opening 11d. The material and manufacturing method of oil pan body 11 are not particularly limited, but it is made by casting and shaping an aluminum material, for example.

[0024] The bottom surface 11a of the oil pan body 11 is generally flat, but one side in the first direction (the side where the opening 11d is provided) is formed to be slightly deeper than the other side. The bottom surface 11a is provided with a bulging portion 11e that bulges upward to avoid contact with various peripheral devices such as a transmission, etc. The bulging portion 11e has a rounded shape so as not to impede the flow of lubricating oil.

[0025] As shown in Figures 5 and 6, the tank 12 also has a generally flat bottom surface 12a, side surfaces 12b that rise upward from the periphery of the bottom surface 12a, and a flange 12c that protrudes outward from the upper edge of the side surface 12b, and the overall shape is bowl-shaped to make it easy to store lubricating oil. The flange 12c is fixed to the oil pan body 11 in a liquid-tight manner via a packing or the like so as to cover the opening 11d, by suitable means such as screws. The material and manufacturing method of the tank 12 are not particularly limited, but for example, the tank 12 is made by press molding a metal material.

[0026] As shown in Figures 1 and 2, a long and narrow first protrusion member 14 is provided on the bottom surface 11a of the oil pan body 11, extending from the other side in the first direction (the side opposite to the side where the opening 11d is provided) toward one side in the first direction (generally toward the opening 11d side) and protruding upward. The first direction is a direction perpendicular to the up-down direction, and generally coincides with the direction in which lubricating oil dripping into oil pan body 11 flows toward opening 11d and is stored in tank 12. Because oil intake port 13 is provided inside tank 12, the first direction generally coincides with the direction in which lubricating oil flows from oil pan body 11 toward oil intake port 13. In this embodiment, the first direction generally coincides with the front-to-rear direction of the vehicle when the internal combustion engine is mounted on the vehicle. In this embodiment, a plurality of first protruding members 14 are provided and are arranged in parallel in a second direction that is substantially perpendicular to the first direction and the up-down direction of the oil pan body 11. The parallel first protrusion members 14 extend from the side surface 11b on the other side in the first direction. In this embodiment, one end (the other end in the first direction) of each first protrusion member 14 is reinforced by being connected to a boss portion 11f that protrudes from the side surface 11b to one side in the first direction. The lubricating oil is guided by the first protruding member 14 and smoothly sent to the opening 11d, and the rigidity of the oil pan body 11 is increased.

[0027] 1 and 2, a partitioned area surrounded by parallel first protrusion members 14 and side surface 11b is formed on bottom surface 11a of oil pan body 11. In this embodiment, two first protrusion members 14 are provided, and the space between one of first protrusion members 14 connected to boss portion 11f on side surface 11b and the opposing side surface 11b of oil pan body 11, and the space surrounded by the two first protrusion members 14 and side surface 11b on the other side in the first direction are each partitioned by first protrusion members 14, forming three partitioned areas. A second protruding member 15 is provided on the bottom surface 11a of this partitioned area. In this embodiment, the second protruding member 15 is provided on the bottom surface 11a of the partitioned area formed by the first protruding member 14 on the left side in FIG. 1 and the opposing side surface 11b of the oil pan body 11. As shown in FIG. 4, the second protruding member 15 has a generally hemispherical shape. As shown in FIG. 3, the second protruding member 15 is convex on the front side (upper side) of the bottom surface 11a and concave on the back side (lower side), and has a thickness that is approximately equal to the thickness of other parts of the bottom surface 11a.

[0028] As shown in FIG. 1, the height of the second protruding member 15 is smaller than the height of the first protruding member 14. In addition, the peripheral surface of the second protruding member 15 is rounded, i.e., circular when viewed from the top and bottom, and has a shape that slopes gently upward when viewed from the second direction, so that the presence of the second protruding member 15 is unlikely to cause resistance to the flow of lubricating oil. The presence of second protruding member 15 increases the rigidity of oil pan body 11, enhancing the vibration damping effect. In this case, the second protruding member 15 is hemispherical, and the entire periphery of the boundary (rising portion) with the bottom surface 11a acts like a rib, so that it can be made longer in a narrow partitioned area compared to a linear rib. That is, the second protruding member 15 has a greater effect of improving rigidity in the second direction than the first protruding member 14. Therefore, it is possible to efficiently obtain a vibration damping effect.

[0029] As shown in Figure 2, the center position of the second protrusion member 15 in a planar view is shifted a predetermined distance from the center position O of the membrane vibration when it is assumed that the second protrusion member 15 does not exist within the partitioned area (Figure 2 shows the state of the membrane vibration schematically). Due to this deviation, the outer periphery of the second protruding member 15, which forms the boundary with the bottom surface 11a, roughly overlaps with the center position O of the membrane vibration. By deliberately shifting the center of the second protrusion member 15 so that the rising part at the boundary with the bottom surface 11a overlaps with the center position O of the membrane vibration, a greater vibration damping effect is achieved and the apex of the second protrusion member 15 can be prevented from vibrating the membrane.

[0030] Here, the method for forming the second protruding member 15 is not particularly limited, but it is simple and inexpensive to form it by pressing the bottom surface 11a. As shown in Figure 3, the thickness of the second protrusion member 15 is the same as that of other parts of the bottom surface 11a, and since the front side is convex and the back side is concave, the surface area is large, which provides good heat dissipation and prevents the oil pan 10 including the second protrusion member 15, and ultimately the lubricating oil, from becoming too hot. Since the portion where the second protruding member 15 is formed is not thickened, an increase in the weight of the oil pan body 11 is also prevented.

[0031] The bottom surface 11a of the oil pan body 11 is almost flat, but as mentioned above, there are differences in depth in some areas, and as shown in Figures 3 and 4(b), at the location where the second protruding member 15 is formed, there is a slight downward slope toward one side in the first direction. As a result, the boundary between the second protruding member 15 and the bottom surface 11a is longer on one side in the first direction than on the other side, and as shown in Figure 4(a), the second protruding member 15 has the appearance of an ellipse with its major axis in the first direction when viewed in a plane (in Figures 4(a) and (b), the center of the sphere is schematically represented by a black dot). Since the first direction is generally aligned with the flow direction of the lubricating oil, the direction perpendicular to the first direction, which may cause resistance to the flow, is generally aligned with the minor axis of the ellipse. Therefore, the dimension in the direction that obstructs the flow of the lubricating oil is shortened, thereby reducing resistance. Since the second protruding member 15 has an elliptical shape in a plan view (viewed from above), no corners are formed at the boundary with the bottom surface 11a, and stress concentration is also prevented.

[0032] On the other hand, unlike the oil pan body 11, the tank 12 is not provided with the second protruding member 15 as shown in FIGS. In this embodiment, the bottom surface 12a of the tank 12 has a small area, so there is little need for reinforcement and large membrane vibrations are unlikely to occur, and therefore the second protruding member 15 is not provided.

[0033] As shown in Figures 1 and 2, a plurality of elongated third protrusion members 16 are arranged in a grid pattern on the bottom surface 11a of the oil pan body 11, extending in a direction connecting the oil pan body 11 as the shallow bottom portion to the tank 12 as the deep bottom portion (first direction) and in a direction perpendicular to this (second direction) and protruding upward. The third protruding member 16 increases the rigidity of the oil pan body 11.

[0034] As shown in FIG. 1, the height of the third protruding member 16 is smaller than the height of the first protruding member 14. Of the third protruding members 16, those that extend in the second direction and protrude upward extend in a direction that intersects with the flow direction of the lubricating oil. Therefore, the third protruding members 16 could obstruct the flow of the lubricating oil, but by reducing their height, the flow resistance is reduced.

[0035] 4(a), the third protrusion member 16 is covered by the hemispherical surface of the second protrusion member 15 at the location where it intersects with the second protrusion member 15. That is, as can be seen from FIG. 3, the height of the third protrusion member 16 is less than the maximum height of the hemispherical second protrusion member 15. In this embodiment, the second protrusion member 15 is provided so as to cover both third protrusion members 16 at the location where the third protrusion members 16 extending in the first direction intersect with the third protrusion members 16 extending in the second direction. The second protruding member 15 and the bottom surface 11a intersect at an obtuse angle, and the surface of the second protruding member 15 is rounded, so that the lubricating oil can easily climb up the slope along the surface. Therefore, the lubricating oil can relatively easily overcome the third protrusion member 16 at the intersection with the second protrusion member 15, further reducing the resistance to the flow of the lubricating oil caused by the third protrusion member 16.

[0036] As shown in FIGS. 5 and 6, the tank 12 also has third protruding members 16 arranged in a grid pattern. The tank 12 is also provided with a fourth protruding member 17 that extends from the side surface 12b of the tank 12 toward the oil suction port 13 and protrudes upward from the bottom surface 12a of the tank 12. In this embodiment, the oil suction port 13 is provided at one end of the tank 12 in the first direction and one end of the tank 12 in the second direction, and the fourth protruding member 17 extends obliquely toward the other side in the first direction and one side in the second direction from a corner where the side surface 12b located on one side in the first direction and facing the first direction is connected to the side surface 12b located on the other side in the second direction and facing the second direction.

[0037] As shown in FIGS. 5 and 6, the height of the third projecting member 16 is lower than the height of the fourth projecting member 17, so that resistance to the flow of lubricating oil is reduced.

[0038] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, and all modifications and alterations within that scope and in a meaning equivalent to the claims are intended to be included.

[0039] The shape of oil pan 10 is not limited to the embodiment as long as it is possible to form first protruding member 14 and second protruding member 15. For example, in the embodiment, oil pan 10 is formed from separate oil pan body 11 and tank 12, but it may also be an integrated type. In addition, in this embodiment, the third protrusion members 16 are lattice-shaped protrusion members having members extending in the first direction and members extending in the second direction, but it is sufficient that the third protrusion members 16 have at least one member extending in the second direction. Also, the third protrusion members 16 in the embodiment may be omitted. Furthermore, the second protruding members 15 may be provided in a plurality of partitioned regions. [Explanation of symbols]

[0040] 10 Oil pan 11 Oil pan body 11a Bottom 11b Side 11c flange 11d aperture 11e Bulge 11f boss section 11g bolt hole 12 Tank 12a Bottom 12b Side 12c flange 13 Oil intake port 14 First protruding member 15 Second protruding member 16 Third protruding member 17 Fourth protruding member O Membrane vibration center

Claims

1. A bowl-shaped oil pan is disposed below the internal combustion engine and receives lubricating oil dripping from the internal combustion engine, The bottom and a side surface rising upward from an edge of the bottom surface; an oil intake port disposed in the oil pan and configured to suck in the dripped lubricating oil, The bottom surface is a first protruding member extending in a first direction from the opposite side of the oil suction port toward the oil suction port and protruding upward from the bottom surface; a second protruding member having a hemispherical surface and protruding upward, the second protruding member being provided in at least one of the partitioned areas on the bottom surface partitioned by the first protruding member and the side surface, The second protruding member has a height lower than that of the first protruding member.

2. The oil pan according to claim 1 , wherein the second protruding member is convex on a front surface of the bottom surface and concave on a rear surface of the bottom surface, and forms a part of the bottom surface.

3. 3. The oil pan according to claim 1, wherein the center of the hemispherical surface of the second protrusion member is located in a position offset from the membrane vibration center before the second protrusion member is provided in the partitioned area in which the second protrusion member is provided.

4. The oil pan according to claim 1 or 2, wherein the second protruding member has an elliptical shape in a plan view, the major axis of which is in the first direction.

5. The bottom surface is a third protruding member extending along a second direction perpendicular to the first direction and protruding upward from the bottom surface; 3. The oil pan according to claim 1, wherein the third protruding member is shorter in height than the first protruding member, and a portion of the third protruding member is covered by the hemispherical surface of the second protruding member.

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