Oil pan with built-in filtering element

An oil pan with a built-in filtering element having an oil flow path which is in communication with an oil pump for filtering oil flowing toward the oil pump, wherein

• the oil flow path includes a bottom flow path having a flow path wall extending along a bottom wall of the oil pan and a side flow path having a flow path wall extending along a sidewall of the oil pan, the bottom flow path extending between an upstream end and a downstream end,
• the sidewall has a drain hole which is opened at the bottom flow path, the filtering element can be inserted into the bottom flow path through the drain hole, and the filtering element extends from a first end to a second end,
• the bottom flow path is provided with a filtering element retaining portion at an upper portion of the upstream end of the bottom flow path, the filtering element retaining portion being configured to retain the first end of the filtering element,
• the drain hole is provided with a plug fixing portion for fixing a closing plug which closes the drain hole at the downstream end of the bottom flow path,
• the closing plug is formed with a filtering element receiver provided at a tip end of the closing plug, the second end of the filtering element inserted into the bottom flow path is abutted against the filtering element receiver,
• the bottom flow path is integrally formed on the bottom wall of the oil pan,
• the upstream end of the bottom flow path opens to a space of the oil pan, and the downstream end of the bottom flow path extends to the sidewall of the oil pan,
• the filtering element includes a screen, the screen is planar and has a rectangular shape when viewed from above, the filter element further includes a frame integrally surrounding a peripheral edge of the screen, the frame is planar as a whole and has a periphery having a rectangular shape when viewed from above, and the periphery of the frame includes a first end and a second end,
• the filtering element is inserted into the bottom flow path from the drain hole, in a state where the closing plug is removed from the drain hole,
• the first end of the filtering element is retained at the upstream end of the bottom flow path with the first end of the periphery of the frame received by the filtering element retaining portion of the bottom flow path, and the second end of the filtering element is received at the downstream end of the bottom flow path with the second end of the periphery of the frame received by the filtering element receiver of the closing plug, such that the filtering element is secured in the bottom flow path to filter oil flow, and
• the filtering element is assembled in the bottom flow path such that the filtering element is inclined downwardly with respect to a longitudinal centerline of the bottom flow path from the first end toward the second end.