JPH10122043A - Oil pan for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress opening/closing and torsion modes generated in the lower edge of the cylinder block of an internal combustion engine by improving the rigidity of the flange of an associated oil pan boy situated around an opening thereof. SOLUTION: A first bridge 12 and a second bridge 13 are arranged across an opening 2c formed in an oil pan body 2 with their ends being connected to bosses 14 and 15 respectively. A first membrane rib 21 and a second membrane rib 22 are formed on both sides of the opening 2c between both bridges 12 and 13 along the inner faces of side edges 2a of the oil pan body 2 so as to connect both bridges 12 and 13 together in the longitudinal direction of an associated engine. Which arrangement constitutes a frame reinforcement structure as a whole. The rigidity of a flange 11 situated around the opening 2c is thus improved to suppress deformation of the cylinder block mounted thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an oil pan mounted on a lower surface of a cylinder block of an internal combustion engine.

[0002]

2. Description of the Related Art In many internal combustion engines typified by internal combustion engines for automobiles, an oil pan having a shallow bottom and a deep bottom is attached to the lower edge of a cylinder block. The pump sucks up the water and sends it to each part. Conventionally, an oil pan composed of an oil pan body integrally cast from an aluminum alloy or the like and a tank part formed of a separate member fixed to one end of the oil pan body in the engine front-rear direction has been known as the oil pan. Have been.

The oil pan main body has a shallow bottom wall at one end in the engine front-rear direction, and a substantially rectangular opening at the bottom at the other end. The tank is generally formed by press-molding a metal plate, and is fixed to a flange formed at the lower edge of the opening of the oil pan body via mounting bolts. Lubricating oil is stored by the tank. Is formed.

[0004]

The oil pan body integrally cast as described above has relatively high rigidity as a whole. In particular, a high rigidity is obtained at the shallow portion, and it acts as a kind of reinforcing member for the skirt portion of the cylinder block connected thereto.

However, in the opening of the oil pan main body, the opening and closing rigidity and torsional rigidity of the side edge are low. Therefore, when the oil pan main body and the cylinder block are connected, the rigidity of the skirt portion is relatively low at one end of the cylinder block corresponding to the opening, and is shown in FIGS. 7A and 7B. Such an opening / closing mode and a twisting mode as shown in FIGS. 7 (c) to 7 (f) occur. For this reason, radiation noise from below the cylinder block and the oil pan increases, leading to deterioration of engine noise.

In order to reduce engine noise, it is conceivable to increase the thickness of the side edges of the oil pan body and the bulkhead of the cylinder block so as to improve the rigidity of both parts. However, in this case, the weight of the engine body is reduced. It is not preferable because it increases.

A main object of the present invention is to suppress an opening / closing mode and a twisting mode generated at a lower edge of a cylinder block located at an opening of an oil pan main body without increasing the weight of an engine main body. And to reduce engine noise.

[0008]

According to the present invention, there is provided a bottom wall which has a side edge which is bolted to a lower edge of a cylinder block of an internal combustion engine all around, and which has a shallow bottom at one end in the front-rear direction of the engine. An oil pan main body that is integrally cast and has an open bottom surface at the other end, and a tank portion that is mounted on the lower surface of the opening of the oil pan main body and that is formed of a metal plate that stores lubricating oil. In the oil pan of the internal combustion engine, a bridge portion along the engine width direction connecting side edges along the engine longitudinal direction on both sides of the opening is formed integrally with the oil pan body so as to cross the opening. In addition, a film-like rib extending along the inner surface of the side edge of the oil pan main body is formed in the engine longitudinal direction so as to be continuous with the bridge portion.

In this configuration, the opening side edges of the oil pan main body are connected to each other, so that the opening / closing rigidity is improved and the torsion is suppressed. Thereby, when the oil pan main body and the cylinder block are connected, a deformation mode generated at the lower edge of the end of the cylinder block corresponding to the opening is suppressed.

[0010] In particular, in the second aspect, both ends of the bridge portion are connected to positions of through holes of mounting bolts for connecting the oil pan body and the cylinder block, respectively. Therefore, the bridge portion and the skirt portion of the cylinder block are firmly connected via the mounting bolts. The rigidity of the lower edge of the cylinder block is effectively improved by the bridge portion.

According to a third aspect of the present invention, a plurality of the bridge portions are provided, and the film-shaped rib is formed between a pair of adjacent bridge portions so as to connect both the bridge portions and the engine longitudinal direction. It is characterized by. For example, the bridge portion includes a vertical wall extending in a vertical direction and an upper wall connected to an upper edge of the vertical wall, and the film-shaped rib is integrally connected to the upper wall. Are formed.

In this configuration, a frame-like reinforcing member is formed by the pair of bridge portions and the film-like ribs.
Reinforce openings. Therefore, the torsional rigidity near the opening of the oil pan main body is further improved.

According to a fifth aspect of the present invention, the film-shaped ribs are formed on both sides of the opening, respectively, and a side edge inner surface of the film-shaped rib located on a side where the crankpin descends with the rotation of the crankshaft. Is characterized in that the width of the projection is set smaller than the width of the projection of the film-shaped rib located on the side where the crankpin rises.

[0014] As the crankshaft rotates, the lubricating oil flows positively downward on the lower wall surface of the crankpin in the crankcase. Therefore, in this configuration, it is possible to avoid interference between the film-shaped rib located on the crankpin descending side and the lubricating oil from above the crankcase.

[0015] On the opposite wall of the crankcase,
The lubricating oil is scooped up by the rise of the crankpin, but since the film-shaped rib located on the crankpin ascending side protrudes largely, the scraping of the lubricating oil is suppressed.

Further, if the projection width of the film-shaped rib located on the lower side of the crankpin is reduced, the rigidity becomes insufficient. Therefore,
According to a sixth aspect of the present invention, in order to secure the rigidity of the film-shaped rib, an oil level gauge insertion hole is provided at a corner portion between the film-shaped rib and one of the bridge portions, and the oil level gauge extends along the outer peripheral portion of the insertion hole. In addition, a corner rib for connecting the film-like rib and the bridge portion is formed.

[0017]

According to the oil pan of the internal combustion engine according to the present invention, the rigidity near the opening is improved by the bridge portion and the film-shaped rib provided at the opening of the oil pan main body. The deformation mode generated at the lower edge is suppressed. Therefore, radiation noise generated from the skirt portion of the cylinder block and from below the oil pan is suppressed, and engine noise is suppressed.

According to the second aspect of the present invention, the bridge portion is connected to the position of the through hole of the mounting bolt formed in the oil pan main body, so that the bridge portion and the skirt portion of the cylinder block are attached to the mounting bolt. Is firmly connected through

According to the third and fourth aspects of the present invention, the provision of the film-like rib further improves the opening / closing rigidity and torsional rigidity of the opening side edge, and accordingly, the opening / closing mode generated at the lower edge of the cylinder block. And the torsional mode is effectively suppressed. Thereby, the radiated sound generated from the skirt portion of the cylinder block and the lower portion of the oil pan is further suppressed.

According to the fifth aspect of the present invention, a large opening area is secured on the lower side of the crankpin, so that the speed of collecting the lubricating oil is improved, and the lubricating oil from above the crankcase is quickly discharged to the tank. You. Further, the film-shaped rib located on the crankpin rising side suppresses the lubricating oil from being lifted up and prevents the lubricating oil from being mixed into the air.

According to the configuration of claim 6, the rigidity of the film-shaped rib located on the crankpin descending side is ensured by the oil level gauge insertion hole and the corner rib along the outer periphery of the insertion hole.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 to 5 show an embodiment in which the present invention is configured as an oil pan of an in-line four-cylinder internal combustion engine.
An oil pan 1 attached to a lower surface of a cylinder block (not shown), specifically, a lower edge of a skirt portion, includes an oil pan main body 2 made of aluminum die-cast, and a tank portion 3 formed by press-forming a metal plate. The oil pan main body 2 forms a flat shallow bottom portion 1a, and the tank portion 3 forms a deep bottom portion 1b in which lubricating oil is stored. The tank part 3
Is located on the lower surface of the front end of the internal combustion engine, is fixed to a flange portion 4 formed on the lower surface of the oil pan main body 2 via a bolt (not shown), and is integrated with the oil pan main body 2. The flange portion 4 is formed along the outer periphery of the opening 2c that opens toward the tank portion 3. Except for the opening 2c, three straightening plates 5, 6, 7 extending in the front-rear direction of the engine are integrally formed on a bottom wall portion 2b serving as a shallow bottom portion 1a of the oil pan main body 2. These current plates 5
7 are formed in a vertical rib shape over substantially the entire length of the bottom wall 2b of the oil pan body 2 in the longitudinal direction of the engine. 1a
A baffle plate (not shown) is disposed so as to cover almost the entire surface of the baffle. In FIG. 1, reference numeral 8 indicates the position of an oil drain hole formed in a cylinder block (not shown). At the rear end of the oil pan main body 2, a transmission mounting portion 9 to which a transmission (not shown) is coupled is formed. A plurality of through-holes 10 for bolts for mounting portions that join the oil pan 1 and a cylinder block (not shown) are formed in a side edge 2 a surrounding the entire circumference of the oil pan main body 2. Further, a flange portion 11 is formed on the upper surface of the side edge 2a of the oil pan main body 2 to be joined to a flange surface on the cylinder block side (not shown).

In the opening 2c of the oil pan main body 2,
A first bridge portion 12 and a second bridge portion 13 along the engine width direction connecting side edges 2a along the engine longitudinal direction on both sides of the opening 2c are formed so as to cross the opening 2c. ing. Specifically, the first bridge unit 1
2 is located in the middle of the opening 2c, and the second bridge 13 is located near the rear edge of the opening 2c. Also,
As shown in FIG. 1, both ends of the first bridge portion 12
The mounting bolts are respectively connected to boss portions 14 formed around the through holes 10. Similarly, both ends of the second bridge 13 are connected to the boss 15 respectively.

The first bridge portion 12 is composed of a pair of vertical walls 12a extending in the vertical direction and an upper wall 12b continuous with the upper edge of the vertical walls 12a. As shown in FIG.
The cross section is formed in a U shape or a channel shape.
The lower edge of the vertical wall 12a is formed so as to linearly connect the lower ends of the boss portions 14 as shown in FIG. The height of the bosses 14 and 15 in the vertical direction is set to be relatively large.
A large overall width in the vertical direction of 3 is also ensured.

The second bridge portion 13 is composed of one vertical wall 13a extending in the vertical direction and an upper wall 13b connected to the upper edge of the vertical wall 13a, as shown in FIG.
The cross section is formed in an L shape. In addition, as shown in FIG. 4, the lower edge of the vertical wall 13a is formed in a shape along the height of the tip edge of a baffle plate (not shown) so that the flow of the lubricating oil from the shallow portion 1a is not hindered. And bottom wall 2b
It is set above the bottom surface of. As shown in FIGS. 1 and 2, the ends of the current plates 5 to 7 on the opening 2c side are:
The end portions of the bottom wall portion 2b protrude from the edge of the engine toward the front end of the engine and extend upward, and each end of the rectifying plates 5 to 7 is connected to the vertical wall 13a and the upper wall 13b of the second bridge portion 13. Is joined to. In addition, in consideration of the flow of the lubricating oil from the shallow bottom portion 1a, the passage cross-sectional area of each lubricating oil passage formed by each of the straightening plates 5 to 7 between the bottom wall portion 2b and a baffle plate (not shown); Bottom wall 2b edge and vertical wall 13a
Are set so that the opening area on the plan view generated between them is substantially equal.

In FIG. 2 to FIG.
Is a bearing cap for supporting the crankshaft 16. First and second bridge portions 12 and 13 are provided at positions facing the bearing caps 17 and 18, respectively.
The upper walls 12b, 13b of the bridge portions 12, 13 are formed so as to be curved downward so that the bridge portions 12, 13 do not interfere with each other. Reference numerals 19 and 20 denote a counterweight and a connecting rod which form a part of the crankshaft 16, and as shown, the connecting rod 20 of the # 1 cylinder is connected between the first bridge portion 12 and the second bridge portion 13. Located between.

The side edge 2a of the oil pan main body 2 is provided between the first bridge portion 12 and the second bridge portion 13 so as to connect the two bridge portions 12, 13 in the longitudinal direction of the engine.
A first film-like rib 21 and a second film-like rib 22 are formed on both sides of the opening 2c along the inner surface.
Specifically, as shown in FIG. 1, the clamp pin (not shown) descends with the rotation of the crankshaft 16, that is, the rotation direction of the counterweight 19 and the like (arrow ω in FIG. 1).
The first film-like rib 21 is formed at a position relatively upstream with respect to (direction). On the other hand, crankshaft 1
A second film-like rib 22 is formed on a side where a clamp pin (not shown) rises with the rotation of 6, that is, a position relatively downstream with respect to the rotation direction ω of the counterweight 19 and the like. Further, the first and second film-shaped ribs 21 and
2 is upper walls 12b, 13b of both bridge portions 12, 13
Are formed continuously and integrally. That is, the film-like rib 2
The upper and lower walls 12b and 13b are continuous so as to have the same plane.

The projecting width of the second film-like rib 22 from the inner surface of the side edge 2a is set as wide as possible without interfering with the trajectory of the rotating object such as the counterweight 19 (FIG. 5). reference). As shown in FIG. 1, the protrusion width of the first film-like rib 21 from the side edge 2 a is equal to the second film-like rib 22.
Is set to be narrower than the protrusion width of.

Except for the corners between the first film-like rib 21 and the second bridge 13, the film-like ribs 21 and 22 and the bridges 12 and 13 have three film-like corners. The inner peripheral edges of the ribs 21 and 22 are R-shaped, and protrude as far as possible to the inner peripheral side as long as they do not interfere with the trajectory of the rotating object such as the counterweight 19. Similarly, at the corner between the vertical wall 12a on the engine front end side of the first bridge portion 12 and the side edge 2a of the oil pan main body 2, the end of the upper wall 12b protrudes toward the inner peripheral side. Perimeter is R
It is formed in a shape (see FIG. 1).

An oblong oil level gauge insertion hole 23 is provided in a corner portion between the first film-like rib 21 and the second bridge portion 13 in a cylindrical shape adjacent to the side edge 2a. An oil level gauge (not shown) inserted toward the tank portion 3 from an oil level gauge insertion hole above the engine (not shown) penetrates.

At the upper edge of the insertion hole 23, the insertion hole 2
Along the outer peripheral portion of No. 3, a corner rib 23a for connecting the first film-like rib 21 and the second bridge portion 13 is provided. The corner rib 23a is formed integrally and continuously with the first film-like rib 21, as shown in FIG.

In each connection portion of the corner rib 23a, the first film-shaped rib 21 and the second bridge portion 13, the inner peripheral edge has an R-shape, and the rotation of the counterweight 19 and the like is performed. It protrudes to the inner peripheral side as much as possible without interfering with the trajectory of the object.

As described above, in the configuration of the above embodiment, the cross section of the first bridge portion 12 is formed in a rectangular channel shape, and the lower portion of the vertical wall 12a is
Since the lower ends of the boss portions 14 are formed so as to be linearly connected to each other, the rigidity of the bridge portion 12 can be maximized. Since the respective ends of the current plates 5 to 7 are connected to the second bridge 13, the ends are supported by the bottom wall 2 b, and the rigidity of the bridge 13 is reduced. Also,
In this configuration, since the rectifying plates 5 to 7 are connected in the engine width direction via the bridge portion 13, the film vibration generated in the shallow bottom portion 1a can also be suppressed. By the first and second bridge portions 12 and 13, the rigidity of the flange portions 11 located on both sides of the opening 2c of the oil pan main body 2 is greatly improved. In particular, the first and second film-like ribs 21 and
Since two and two bridge portions 12 and 13 form a continuous reinforcing structure in a rectangular frame shape, the rigidity of the flange portion 11 near the opening 2 c of the oil pan main body 2 is improved.
In particular, the torsional rigidity is greatly improved. In addition, when the oil pan body 2 is connected to the cylinder block, both ends of the first and second bridge portions 12 and 13 are attached to the skirt portions of the cylinder block at the boss portions 14 and 15 by attaching mounting bolts. The skirt portion is effectively reinforced because it is firmly connected to the skirt portion. As a result, the opening / closing mode and the twisting mode generated at the lower edge of the cylinder block are suppressed. Therefore, radiation noise generated from the skirt portion of the cylinder block and from below the oil pan is suppressed, and engine noise is reduced.

Further, since the width of the first film-like rib 21 is small, the opening area on the crankpin descending side can be increased. Thereby, the speed of collecting the lubricating oil through the opening 2c is improved, and the lubricating oil from above the crankcase is quickly discharged to the tank 3. Even if the width of the first film-like rib 21 is reduced in this manner, the lack of rigidity of the first film-like rib 21 is compensated for by providing the oil level gauge insertion hole 23 and the corner rib 23a.
Further, the second film-shaped rib 22 can prevent the lubricating oil from being swept up by a rotating object such as the counterweight 19.

[Brief description of the drawings]

FIG. 1 is a plan view of an entire oil pan according to the present invention.

FIG. 2 is a sectional view of the entire oil pan taken along line AA in FIG.

FIG. 3 is a sectional view of the oil pan main body taken along line BB of FIG. 1;

FIG. 4 is a cross-sectional view along the line CC.

FIG. 5 is a cross-sectional view along the line DD.

FIG. 6 is a sectional view of the oil level gauge insertion hole along the line EE in FIG. 1;

FIG. 7 is an explanatory diagram of various modes generated at a lower edge of a cylinder block.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Oil pan 2 ... Oil pan main body 3 ... Tank part 12 ... First bridge part 12a, 13a ... Vertical wall 12b, 13b ... Upper wall 13 ... Second bridge part 21 ... First film-like rib 22 ... First 2 film-like ribs 23: oil level gauge insertion hole 23a: corner rib

Claims (6)

[Claims] 1. An internal combustion engine having a side edge which is bolted to a lower edge of a cylinder block on the entire circumference, a bottom wall serving as a shallow bottom at one end in the front-rear direction of the engine, and a bottom surface at the other end. An oil pan body that is integrally cast with an opening,
A tank portion made of a metal plate that is attached to the lower surface of the opening portion of the oil pan body and stores lubricating oil, wherein the side edges along the engine longitudinal direction on both sides of the opening portion are provided. A bridge portion along the engine width direction is formed integrally with the oil pan main body so as to cross the opening, and is continuous with the bridge portion along an inner surface of a side edge of the oil pan main body. An oil pan for an internal combustion engine, wherein the film-shaped ribs are formed in a longitudinal direction of the engine. 2. The internal combustion engine according to claim 1, wherein both ends of the bridge portion are connected to positions of through holes of mounting bolts for connecting the oil pan body and the cylinder block. Oil pan. 3. A method according to claim 1, wherein said bridge is provided with a plurality of said bridge portions, and said film-like rib is formed between a pair of adjacent bridge portions so as to connect both bridge portions in a longitudinal direction of the engine. An oil pan for an internal combustion engine according to claim 1. 4. The bridge portion includes a vertical wall extending in a vertical direction, and an upper wall continuous with an upper edge of the vertical wall,
4. An oil pan for an internal combustion engine according to claim 3, wherein said film-like rib is formed integrally and continuously with said upper wall. 5. The film-shaped rib is formed on both sides of the opening, and the width of the film-shaped rib located on the side where the crankpin descends with the rotation of the crankshaft from the inner side edge is: The oil pan of an internal combustion engine according to claim 3 or 4, wherein the projecting width of the film-shaped rib located on the side where the crankpin rises is set to be narrower. 6. An oil level gauge insertion hole is provided in a corner portion between the film-shaped rib positioned on the crankpin descending side and one of the bridge portions, and the oil level gauge insertion hole extends along an outer peripheral portion of the insertion hole. 6. An oil pan for an internal combustion engine according to claim 5, wherein a corner rib for connecting the film-like rib and the bridge portion is formed.