JP2020153260A - Oil pan for automobile internal combustion engine - Google Patents

Abstract

To provide an oil pan to be used for a horizontal front exhaust type internal combustion engine mounted on a vehicle body, for improving the rigidity of a power plant including the oil pan even when forming a hollow part into which an exhaust pipe passes.SOLUTION: With the hollow part formed, a bottom 9 of an oil pan 1 includes a shallow bottom part 9a located at a site of the hollow part, and a deep bottom part 9b located in front thereof. On each of right and left side walls 3, a step-shaped reinforcement part 24 is formed at a position somewhat higher than the shallow bottom part 9a while extending over the whole length. Thus, rigidity against vertical bending and torsion is improved. As a result, the rigidity of the power plant is also improved.SELECTED DRAWING: Figure 6

Description

The present invention relates to an oil pan of an internal combustion engine for automobiles.

In an internal combustion engine, an oil pan is fixed to the lower surface of the cylinder block with bolts, and a mission case is fixed so as to straddle the rear surface of the cylinder block and the rear surface of the oil pan. Is configured. In addition, the lower part of the front cover that covers the timing chain is often fixed to the front of the oil pan, and in this case, the front cover is also a part of the power plant.

What is important in a power plant is to increase the overall rigidity. Regarding this point, Patent Document 1 discloses that a recess and a rib are formed on the rear surface of the oil pan as a means for improving the rigidity of the oil pan.

Japanese Unexamined Patent Publication No. 62-247158

When an internal combustion engine for automobiles is mounted in the engine room of a car body, it is roughly divided into a transverse type with the crankshaft center facing the vehicle width direction and a longitudinal type with the crankshaft center facing the front and rear direction of the car body. Further, in the transverse type, there are front exhaust with the exhaust side facing the front of the vehicle body and rear exhaust with the exhaust side facing the rear of the vehicle body, and in the front exhaust method, the engine body and exhaust system members use the running wind. There are points such as being able to cool.

Since the end of the exhaust pipe is located at the rear of the vehicle body, the exhaust pipe is pulled out behind the oil pan by diving under the oil pan in the transverse engine of the front exhaust system. Therefore, as disclosed in Patent Document 1, a hollow portion is formed on the lower surface of the oil pan, and the exhaust pipe is passed through the portion of the hollow portion.

Then, when a hollow portion is formed in the oil pan, the bottom portion of the oil pan becomes a shallow bottom portion at the hollowed portion and the other portion becomes a deep bottom portion, but the mission case is fixed to the end portion of the shallow bottom portion. Therefore, there is a problem that the rigidity of the oil pan (particularly, the rigidity against the bending force acting from the vertical direction) is lowered, and as a result, the rigidity of the power plant is lowered.

Then, when Patent Document 1 is examined, even if the rear part of the oil pan is partially reinforced, it does not contribute much to the improvement of the rigidity of the entire oil pan. It is understood that it does not contribute much to the improvement of the rigidity of the entire power plant (in particular, it is understood that it hardly contributes to the improvement of the rigidity against an external force such as bending the crankshaft in the vertical direction).

The invention of the present application was made in the wake of the current situation as described above, and aims to realize an oil pan capable of contributing to an increase in the rigidity of a power plant with a simple structure.

The invention of the present application is
"Internal combustion engine placed in the engine room provided at the front of the vehicle with the crankshaft center in a long posture in the vehicle width direction and the exhaust side facing the vehicle forward direction."
This oil pan is related to the oil pan used in
"It has a pair of side walls where the cylinder block is fixed on the upper surface, a front wall located on the side of the front cover that covers the timing chain, and a rear wall where the mission case is fixed, and there is an exhaust pipe at the bottom. It forms a hollowed out portion through which the bottom portion is a shallow bottom portion at the portion of the hollowed out portion and a deep bottom portion at the portion in front of the hollowed portion. "
It has a basic structure.

Then, in the above basic configuration, as described in claim 1,
"On both side walls, stepped or ribbed reinforcing portions when viewed from the direction of the crankshaft are formed so as to extend long in the front-rear direction at least at the shallow bottom portion."
It has the feature.

The invention of the present application also includes the configuration of claim 2. The invention of claim 2 is claimed in claim 1.
"The reinforcing portion is formed over the entire length of the side wall, and the front end is formed with a front extension portion that wraps around to the front wall.
The front cover is fixed to the front surface of the front wall, and the front extension portion of the reinforcing portion is set at a height that overlaps or is close to the lower end portion of the front cover. "
It is configured as.

Since the mission case is fixed to the rear surface of the cylinder block and the oil pan in the state of a cantilever, the weight of the mission case acts on the oil pan as an external force that bends the oil pan in the vertical direction. The movement of the piston also acts as an external force that bends the cylinder block and the oil pan in the vertical direction.

Since the oil pan of the internal combustion engine of the horizontal pre-exhaust type has a hollowed portion, the rigidity against an external force in the vertical direction (to be exact, the cylinder bore axis direction) is particularly low, but in the present invention, it is in the crankshaft center direction. Since the stepped or ribbed reinforcing portion is formed on the long side wall at least at the shallow bottom portion, the rigidity of the oil pan against bending and twisting in the vertical direction is remarkably improved.

The reinforcing portion has a simple stepped or ribbed structure, and can be integrally formed when, for example, an oil pan is manufactured by die casting or casting. Therefore, there is no cost increase or weight increase. Therefore, it is possible to improve the rigidity of the power plant including the cylinder block, the oil pan, and the mission case without causing the problem of cost increase.

If a stepped form is adopted as the reinforcing portion, the amount of material used does not increase, so there is an advantage that an increase in weight can be avoided. In addition, the oil returning from the cylinder block often runs down the inner surface of the side wall of the oil pan, but if the reinforcing portion is composed of stepped portions, the oil that has run down the inner surface of the side wall hits the stepped portion and the flow velocity decreases. By doing so, the bubbles contained in the oil can be eliminated.

The oil jet for cooling the piston may fall and be shaken off by the rotation of the crankshaft and adhere to the inner surface of the side wall. In this case as well, the oil that has fallen down the inner surface of the side wall hits the step and the flow velocity. By reducing the amount of air, the bubbles contained in the oil can be eliminated.

As described above, when the step portion is adopted as the reinforcing portion, it also has the effect of eliminating air bubbles in the oil, so that there is an advantage that air bubbles can be suppressed from being mixed in the oil sucked up by the oil pump. In particular, when using a hydraulic lash adjuster to eliminate the valve clearance of the intake valve and exhaust valve, air bubbles should be avoided as much as possible in the oil, but if a step portion is formed as a reinforcing portion, the oil It is particularly useful when applied to an oil pan of an internal combustion engine equipped with a lash adjuster because of its high bubble elimination effect. The same effect can be enjoyed by forming the reinforcing portion with inward ribs.

Further, in both the stepped reinforcing portion and the rib-shaped reinforcing portion, the area of the inner surface of the oil pan is increased by forming the reinforcing portion, so that the cooling performance of the oil can be improved. Therefore, there is an advantage that the excessive temperature rise of the oil can be suppressed and the deterioration of the oil can be suppressed in the operation in a high temperature environment.

In claim 2, since the reinforcing portion wraps around to the front wall, the rigidity of the oil pan and the power plant can be further improved. Further, in the invention of claim 2, the front cover serves as a reinforcing member for strengthening the fixing between the cylinder block and the oil pan. Therefore, the front cover also constitutes a part of the power plant, but the reinforcement in the oil pan. Since the front extension of the part overlaps or is close to the lower end of the front cover, the bonding strength between the front cover and the oil pan can be significantly improved. As a result, the rigidity of the power plant can be further improved.

It is a top view of the embodiment. It is a side view. It is a bottom view. It is a front view (front view). It is a back part (rear view). FIG. 6 is a sectional view taken along line VI-VI of FIG.

Next, an embodiment of the present invention will be described with reference to the drawings. In the following, the front-back and left-right terms are used to specify the direction, but the front-back direction is the crankshaft center direction, and the left-right direction is the direction orthogonal to the crankshaft center and the cylinder bore axis. Regarding the front and the back, the side where the timing chain is arranged is the front, and the side where the mission case is arranged is the back. The direction is clearly shown in FIG.

(1). Basic structure The internal combustion engine to which this embodiment is applied has three cylinders, and as shown in FIG. 2, the oil pan 1 is long in the direction of the crankshaft O and has a cylinder block 2 on the upper surface 3a. The left and right side walls 3 to be fixed, the front wall 5 to which the front cover 4 is fixed, the rear wall 7 to which the mission case 6 is fixed, and the bottom 9 continuous with the front and rear walls 5, 7 and the side wall 3 have. The crankshaft center O is located slightly above the upper surface 3a of the oil pan 1.

In FIG. 1, the range of the upper surface 3a of the side wall 3 is shown by parallel diagonal lines. Therefore, the parallel diagonal lines in FIG. 1 do not indicate the cross section. An upper tap hole 10 for fixing the cylinder block 2 is formed on the upper surface 3a of the side wall 3 along the circumferential direction. Further, a vertically long rib 11 for securing an area for forming the upper tap hole 10 is formed on the inner surface of each tap hole 10 in the side wall 3.

At the rear portion of the bottom portion 9, a hollow portion 14 through which the exhaust pipe 13 passes is formed. Therefore, the bottom portion 9 is composed of a shallow bottom portion 9a having a low depth, a deep bottom portion 9b located in front of the shallow bottom portion 9a, and a stepped wall 9c connecting the two. Needless to say, the strainer is arranged at the deep bottom 9b.

As can be understood from FIGS. 3 and 4, the front wall 5 extends to the left and right outside of the left and right side walls 3, and a front polymerization surface 15 on which the front cover 4 overlaps is formed. A front tap hole 16 for fixing the front cover 4 is formed on the prepolymerized surface 15. The parallel diagonal lines shown in FIG. 4 also indicate a flat surface, not a cross section. A plurality of recesses 17 that are open forward are formed on the prepolymerized surface 15. Further, a front recess 18 through which the front crank cap (not shown) is released is opened upward in the front wall 5.

As shown in FIG. 5, a rear polymerization surface 19 in close contact with the mission case 6 is formed on the back wall 7, and a plurality of rear tap holes 20 for fixing the mission case 6 are formed on the rear polymerization surface 19. There is. Further, in the rear wall 7, a groove hole 21 through which the bearing of the crankshaft escapes is opened upward in a state concentric with the crankshaft center O.

As shown in FIGS. 1 and 6, two left and right reinforcing ribs 22 are formed on the inner surface of the shallow bottom portion 9a in a long posture in the front-rear direction. The reinforcing rib 22 reaches the deep bottom portion 9b via the step wall 9c. The internal combustion engine to which this embodiment is applied is a slant type in which the cylinder bore axis is slightly tilted forward. In FIGS. 4 to 6, the exhaust side of the deep bottom portion 9b is higher, but in reality, as shown in FIG. 6, the cylinder bore axis O2 is tilted forward with respect to the vertical line O2, and the deep bottom portion 9b The bottom is in a horizontal position.

The oil pan 1 is a die-cast product made of aluminum, and has a draft on the inner surface so as to expand upward. Further, as shown in FIG. 6, the side wall 3 on the exhaust side is substantially parallel to the cylinder bore axis O2, while the side wall 3 on the intake side is wider than the cylinder bore axis O2, but the cylinder bore. Is slanted, so that the side wall 3 on the exhaust side actually leans forward with respect to the vertical line O3.

An oil drop hole is formed in the wall of the cylinder block 2 on the exhaust side, but the oil flowing down from the oil drop hole in the cylinder block 2 is the inner surface of the side wall 3 on the exhaust side as shown by an arrow 23 in FIG. It flows to the bottom 9 of the oil pan 1 along.

(2). Reinforcing step portion As shown in FIGS. Is formed over the entire length. For example, as can be understood from FIG. 2, the stepped reinforcing portion 24 is formed at a position slightly higher than the shallow bottom portion 9a of the bottom portion 9. Further, as shown in FIG. 1, the stepped reinforcing portion 24 has a portion formed so as to wind the vertically long rib 11. In FIGS. 1, 2 and 3, the stepped reinforcing portion 24 is provided with parallel diagonal lines to clarify the range.

As shown in FIGS. 1 and 3, the stepped reinforcing portion 24 is continuously formed with a front extension portion 24a that wraps around the inner surface of the front wall 5 and a rear extension portion 24b that wraps around the inner surface of the rear wall 7. ing. As shown in FIGS. 2 and 3, the front extension portion 24a has a height close to the lower end of the prepolymerized surface 15 to which the front cover 4 is fixed. On the other hand, the rear extension portion 24b has a height that overlaps with the rear overlapping surface 19 on which the mission case 6 overlaps.

As is clearly shown in FIG. 6, the side wall 3 is bent in a crank shape so that the upper portion of the stepped reinforcing portion 24 is located on the left and right outer sides of the lower portion. Therefore, it exhibits high rigidity against an external force that bends in the vertical direction, an external force that bends in the left-right direction, or an external force that twists around the axis in the direction of the crankshaft O.

In particular, in the present embodiment, since the front extension portion 24a and the rear extension portion 24b are formed on the stepped reinforcing portion 24, the rigidity against torsion is significantly increased. Further, since it is sufficient to change the shape of the peripheral wall of the oil pan 1 for the stepped reinforcing portion 24, the processing cost does not increase and the weight does not increase, so that cost increase and fuel consumption deterioration do not occur.

Further, as described above, the oil flowing down from the oil drop hole of the cylinder block 2 flows along the inner surface of the side wall 3 on the exhaust side, but due to the stepped reinforcing portion 24 in the middle, the flow velocity in the stepped reinforcing portion 24 increases. Since it is lowered, the contact time and the contact distance with the side wall 3 become long, and the effect of dissipating the contained air bubbles becomes high.

As shown by the arrow 25, the oil that functions as the oil jet for cooling the piston is blown off by the crank arm and the counterweight and adheres to the side wall 3 on the exhaust side, and this oil also flows down the inner surface of the side wall 3. Since the flow velocity is reduced by the stepped reinforcing portion 24, the emission of air bubbles is promoted. Since the oil adhesion area increases when the stepped reinforcing portion 24 is provided, it can also contribute to the improvement of the oil cooling performance.

In the embodiment, the stepped reinforcing portion 24 bent in a crank shape is adopted as the reinforcing portion, but as the reinforcing portion, ribs protruding inward or outward or both inward and outward can be adopted. However, if the stepped reinforcing portion 24 is adopted as in the embodiment, there is an advantage that even if the oil pan 1 is a die-cast product, it can be easily manufactured.

The invention of the present application can be embodied in an oil pan of an internal combustion engine for automobiles. Therefore, it can be used industrially.

O Crankshaft center 1 Oil pan 2 Cylinder block 3 Side wall 3a Side wall upper surface 4 Front cover 5 Front wall 6 Mission case 7 Rear wall 9 Bottom 9a Shallow bottom 9b Deep bottom 14 Crushed part 24 Stepped reinforcement

Claims (2)

An oil pan used for an internal combustion engine, which is arranged in an engine room provided at the front of the vehicle with the crankshaft center in a long posture in the vehicle width direction and the exhaust side facing the vehicle forward direction.
It has a pair of side walls to which the cylinder block is fixed on the upper surface, a front wall located on the side of the front cover covering the timing chain, and a rear wall to which the mission case is fixed, and an exhaust pipe passes through the bottom. In a configuration in which a hollow portion is formed, and therefore the bottom portion is a shallow bottom portion at the portion of the hollow portion and the portion on the front side thereof is a deep bottom portion.
Reinforcing portions that are stepped or ribbed when viewed from the crankshaft direction are formed on both side walls so as to extend long in the front-rear direction at least at the shallow bottom portion.
Oil pan for internal combustion engines for automobiles. The reinforcing portion is formed over the entire length of the side wall, and a front extension portion that wraps around to the front wall is formed at the front end.
The front cover is fixed to the front surface of the front wall, and the front extension portion of the reinforcing portion is set at a height that overlaps or is close to the lower end portion of the front cover.
The oil pan for an internal combustion engine for an automobile according to claim 1.

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