To achieve an improved stiffness, the oil pan includes bottom wall having a shallow bottom wall (16), a deep bottom wall (17), and a connecting wall (18) located between the shallow bottom wall and the deep bottom wall, arranged in a lateral direction, and a side wall extending from a peripheral edge of the bottom wall. The side wall includes a first side wall (11) located on a front side of the bottom wall and a second side wall (12) located on a rear side of the bottom wall, the connecting wall being provided with a first rib (31) extending in a fore and aft direction and connecting the first side wall and the second side wall to each other.

The present disclosure describes an oil pan structure including a storing portion that stores oil for an internal combustion engine. The storing portion includes a shallow bottom portion, a deep bottom portion deeper than the shallow bottom portion, and a connection surface that connects the shallow bottom portion and the deep bottom portion between the shallow bottom portion and the deep bottom portion. A side wall is formed at a position facing the connection surface with the shallow bottom portion interposed between the side wall and the connection surface. A rib is formed on a back surface of the shallow bottom portion so as to extend from one side or another side of the side wall in a width direction of the shallow bottom portion toward an end portion of the connection surface on an opposite side in the width direction.

To achieve an improved rigidity, the an oil pan (3) for forming a lower end part of an internal combustion engine (1) comprises a bottom wall (6) and a side wall (7) extending from a peripheral edge of the bottom wall, wherein the bottom wall includes a pair of first planar surface portions (35) extending in a lateral direction and provided on either end of the bottom wall with respect to a fore and aft direction orthogonal to the lateral direction, and a curved surface portion (36) recessed downward with respect to the first planar surface portions.

A composite oil pan for a work vehicle engine and a method of forming the composite engine oil pan include forming a sheet of metal into a first pan and open molding a fiber-reinforced polymer resin onto the first pan forming a second pan. The first pan has a first bottom wall and first peripheral walls extending from edges of the first bottom wall to define a sump, the first peripheral walls terminating in a first peripheral flange. The second pan has a second bottom wall and second peripheral walls abutting the first bottom wall and the first peripheral walls, the second peripheral walls terminating in a second peripheral flange. The first pan defines a thin metal structure with an inner surface extending across the first bottom wall, first peripheral walls and first peripheral flange; the second pan reinforces the first pan without abutting the inner surface.

An internal combustion engine, having a cylinder crankcase delimiting a crank chamber and a lubricant pan accommodating a lubricant sump, which has a lubricant pan upper part arranged between the crank chamber and the lubricant sump and a lubricant pan lower part fastened on the lubricant pan upper part. Multiple ridges originate from a base component of the lubricant pan upper part in the direction of the lubricant sump, which ridges partially intersect and thus form chambers which are peripherally closed in section between them, and lubricant passage openings formed in the lubricant pan upper part open into at least part of the chambers, via which openings the crank chamber and the lubricant sump are fluidically connected.

A composite oil pan for a work vehicle engine and a method of forming the composite engine oil pan include forming a sheet of metal into a first pan and open molding a fiber-reinforced polymer resin onto the first pan forming a second pan. The first pan has a first bottom wall and first peripheral walls extending from edges of the first bottom wall to define a sump, the first peripheral walls terminating in a first peripheral flange. The second pan has a second bottom wall and second peripheral walls abutting the first bottom wall and the first peripheral walls, the second peripheral walls terminating in a second peripheral flange. The first pan defines a thin metal structure with an inner surface extending across the first bottom wall, first peripheral walls and first peripheral flange; the second pan reinforces the first pan without abutting the inner surface.

[Summary] Oil pan (10) for containing engine oil is configured so as to be divided into metallic upper oil pan (13) and synthetic resin lower oil pan (14). Upper oil pan (13) and lower oil pan (14) are respectively provided with beam (25) and rib (24), which extend in the front-rear direction of the vehicle. Beam (25) and rib (24) are caused to face each other with gap (26) provided therebetween. When external force which can deform lower oil pan (14) in the front-rear direction of the vehicle acts on lower oil pan (14) due to the interference thereof with curbstones or the like, beam (25) and rib (24) come into contact with each other and prevent lower oil pan (14) from deforming in the front-rear direction of the vehicle.

The oil storage structure includes an oil pan that closes a lower opening of the transmission case and forms an oil pool in a lower space inside the transmission case, and a strainer having a suction port for oil located in the oil pool. The suction port for the oil is provided so as to face a bottom wall portion of the oil pan with a gap in between, and the bottom wall portion of the oil pan is provided with a protruding portion protruding toward the suction port, with the protruding portion being formed in a direction across the suction port as viewed from the bottom wall portion.

The oil storage structure includes an oil pan that closes a lower opening of the transmission case and forms an oil pool in a lower space inside the transmission case, and a strainer having a suction port for oil located in the oil pool. The suction port for the oil is provided so as to face a bottom wall portion of the oil pan with a gap in between, and the bottom wall portion of the oil pan is provided with a protruding portion protruding toward the suction port, with the protruding portion being formed in a direction across the suction port as viewed from the bottom wall portion.

A hybrid oil pan for a vehicle includes a body part which is molded with a plastic material to reduce the weight, and a portion of the oil pan that is fastened to a transmission has increased dynamic rigidity to cope with the deformation caused by the dynamic behavior of the transmission.