[OBJECT] To provide a resin-made oil pan without breakage even when the oil pan strikes against an obstruction. [MEANS TO SOLVE] A bottom wall 2 of an oil pan 1 made of resin material has a front side wall section 5 that is located at a vehicle front side and a rear side wall section 6 that is located at a vehicle rear side with respect to the front side wall section 5 and continues to the front side wall section 5 at a predetermined angle. The front side wall section 5 is set so as to have an inclination so that as a position on the front side wall section 5 gets closer to the vehicle rear side, the position on the front side wall section 5 is located in a lower position in a vehicle up-and-down direction in a state in which the oil pan 1 is secured to a cylinder block mounted on a vehicle. As an external force absorption means, a plurality of lateral ribs 7 , each of which has an almost rectangular shape in cross section and extends along a vehicle width direction, are formed on an outer wall surface 5 a of the front side wall section 5.
1. An oil pan secured to a lower portion of a vehicle and made of resin material, comprising:
a bottom wall having a front side wall section that is located at a vehicle front side and a rear side wall section that is horizontally located at a vehicle rear side with respect to the front side wall section and continues to the front side wall section at a predetermined angle; and
an external force absorption section that is provided at the front side wall section and inclines downward in a vehicle up-and-down direction toward the vehicle rear side and moderates and absorbs an external force that is inputted to the front side wall section, wherein
the external force absorption section comprises a plurality of resin-made longitudinal ribs that protrude from an outer wall surface of the front side wall section so as to extend along a vehicle front-and-rear direction, and
each of the longitudinal ribs is formed so that the vehicle rear side portion of each of the longitudinal ribs is relatively thick and the top end of the vehicle rear side portion of each of the longitudinal ribs becomes relatively thinner toward the vehicle front side.
2. The oil pan as claimed in claim 1 , wherein
a cross sectional shape of a longitudinal rib gradually changes from a wedge shape to an isosceles trapezoid shape from the vehicle front side toward the vehicle rear side.
3. The oil pan as claimed in claim 2 , wherein
the cross sectional shape of the longitudinal rib further gradually changes from the isosceles trapezoid shape to a rectangular shape from the vehicle front side toward the vehicle rear side.
4. The oil pan as claimed in claim 1 , wherein
as a position of a longitudinal rib gets closer to the vehicle rear side, a protruding amount from the outer wall surface of the front side wall section of the longitudinal rib becomes greater.
5. The oil pan as claimed in claim 1 , wherein
a longitudinal rib is formed so that the vehicle rear side portion of the longitudinal rib is relatively thick in a vehicle width direction and the top end of the vehicle rear side portion of the longitudinal rib becomes relatively thinner in the vehicle width direction toward the vehicle front side.
6. The oil pan as claimed in claim 1 , wherein
the longitudinal ribs are provided at regular intervals in a vehicle width direction.
7. The oil pan as claimed in claim 1 , wherein
the longitudinal ribs are provided at irregular intervals in a vehicle width direction.