JPH0533721Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an oil pan structure for an engine.

(Prior Art) In general, oil pans have a two-tiered bottom structure with a shallow bottom portion 51 on one side and a deep bottom portion 52 on the other side with a boundary wall 53 in between, as shown in FIG. When the oil pan 50 is viewed in the direction of the crankshaft, there are three corner parts: a first corner part 61 formed by the shallow bottom wall 54 and the transmission case mounting flange 56;
4 and a boundary wall 53.
There are three corner portions: 2 and a third corner portion 63 formed by the boundary wall 53 and the deep bottom wall 55 (see, for example, Japanese Utility Model Application Publication No. 173754/1983).

In such a two-tiered oil pan, the corner portions 61, 62, and 63 are relatively easily displaced within the oil pan 50 when subjected to engine operating vibrations. 50 may vibrate significantly in the vertical direction, leading to an increase in engine noise.

As a method of suppressing this, conventionally, ribs 57 and 5 are provided at each corner portion 61, 62, and 63, respectively.
8 and 59 are generally provided.

However, among these ribs, the ribs 57 and 58 provided at the first corner portion 61 and the second corner portion 62 are provided on the outer surface side of the oil pan 50, so there is no problem; Since the ribs 59 provided at the corner portions 63 are provided inside the oil pan 50 and protrude into the deep bottom portion 52, the volume of the deep bottom portion 52 may be reduced by the volume of the ribs 59, or This rib 59 restricts the mounting position or shape/dimensions of the oil strainer disposed in the deep bottom portion 52, resulting in problems such as a reduction in the degree of freedom in design.

(Purpose of the invention) The present invention is an attempt to solve the problems pointed out in the above section of the prior art. The purpose of this is to increase the strength without reducing the volume or the degree of freedom in design.

(Means for Achieving the Object) As a means for achieving the above object, the present invention has a shallow bottom section on one side and a deep bottom section on the other side of the boundary wall, which are integrally molded by casting. In the oil pan of the engine, the lower end portion of the boundary wall is a rib portion that protrudes below the lower surface of the deep bottom portion.

(Function) In the present invention, by the above-mentioned means, the rigidity at the corner portion of the lower end of the boundary wall is improved by the rib portion, and the bending displacement of the oil pan due to engine vibration is reduced as much as possible. .

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 1 to 3.

1 to 3 show an oil pan 1 of an engine having an oil pan structure according to an embodiment of the present invention.
It is shown. This oil pan 1 is an oil pan having a two-stage bottom structure integrally cast from a light alloy, and has a shallow bottom portion 2 on one side of a boundary wall 9 horizontally disposed approximately at the center in the direction of the crankshaft, and a shallow bottom portion 2 on the other side. A deep bottom portion 3 is formed on each side. The shallow bottom portion 2 and the deep bottom portion 3 are surrounded by a pair of left and right side walls 5, 6 and a pair of front and rear end walls 7, 8, and a cylinder block mounting flange 10 is formed at the upper open end thereof. Further, a substantially semicircular transmission case 11 is integrally formed on the end wall 8 on the shallow bottom portion 2 side, and protrudes further downward from the lower surface of the shallow bottom wall 4A.

Furthermore, as shown in FIG. 3, this oil pan 1 has three corner portions in the crankshaft direction,
That is, a first corner portion 21 formed between the mission case 11 and the shallow side bottom wall 4A, and a second corner portion formed between the shallow side bottom wall 4A and the boundary wall 9. 22 and a third corner portion 23 formed between the boundary wall 9 and the deep bottom wall 4B. The presence of such corner portions may impair the bending rigidity of the oil pan 1 in the vertical direction and encourage vertical vibration of the oil pan 1.
As mentioned above, these corner portions need to be reinforced.

Therefore, in this embodiment, the first corner portion 21 is connected to a sloped wall 32 connecting the mission case 11 and the shallow side bottom wall 4A in an arc shape, and the sloped wall 32 and the shallow side bottom wall. It is reinforced with ribs 31, 31... arranged between 4A, and the second corner part 2
2 is reinforced with substantially triangular ribs 33, 33, . . . provided across the shallow side bottom wall 4A and the boundary wall 9.

Furthermore, the third corner portion 23 is reinforced with a rib (see FIG. 3, reference numeral 59) provided inside the deep bottom portion 3 and spanning between the boundary wall 9 and the deep bottom side bottom wall 4B. As mentioned above, the provision of the ribs causes problems such as a reduction in the volume of the deep bottom part 3 and various restrictions on the arrangement of the oil strainer. The lower end 9a of the boundary wall 9 near the deep bottom wall 4B is made to protrude further downward than the lower surface of the deep bottom wall 4B to form a rib portion 15, and the width of the oil pan 1 is Rigidity at the third corner portion 23 is ensured by the rib portion 15 extending in the direction (perpendicular to the crankshaft direction).

Therefore, in this embodiment, it is possible to effectively improve the strength of the oil pan 1 without reducing the capacity of the oil pan 1 or imposing restrictions on the oil pan design.

Furthermore, if the boundary wall 9 is formed in a substantially arc shape in the direction perpendicular to the crankshaft direction as in this embodiment, not only vibrations in the vertical direction of the oil pan 1 but also lateral bending and torsional vibrations can occur as described above. This has the advantage that the rigidity of the oil pan 1 can be further increased.

(Effect of the invention) The engine oil pan structure of the present invention has a shallow bottom part on one side and a deep bottom part on the other side through a boundary wall, and is integrally formed by casting. The lower end portion of the wall is characterized by a rib portion that protrudes below the lower surface of the deep bottom portion.

Therefore, according to the engine oil pan structure of the present invention, (1) the rib portion protruding from the lower end of the boundary wall increases the rigidity at the corner portion between the boundary wall and the bottom wall of the oil pan; (2) Since the rib part is formed on the lower surface side of the oil pan and protrudes downward from the deep bottom part, the rib part There is no need to reduce the volume of the oil pan due to the formation of the oil strainer, or to save money on the installation position of the oil strainer.
Practical effects such as improved flexibility in designing the oil pan can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of an oil pan equipped with an oil pan structure according to an embodiment of the present invention, and FIG.
FIG. 3 is a plan view of the oil pan shown in the figure, FIG. 3 is a vertical cross-sectional view taken from FIG. 2, and FIG. 4 is a vertical cross-sectional view of an oil pan having a conventional structure. 1... Oil pan, 2... Shallow bottom, 3... Deep bottom, 4... Bottom wall, 5, 6... Side wall, 7... End wall, 8... End wall, 9... Boundary wall, 10 ... Cylinder block, 11 ... Mission case, 15
...Rib part.

Claims (1)

[Scope of utility model registration request] In an engine oil pan that is integrally formed by casting and has a shallow bottom part on one side and a deep bottom part on the other side with a boundary wall interposed therebetween, the lower end of the boundary wall is located below the lower surface of the deep bottom part. An engine oil pan structure characterized by a protruding rib part.