Abstract: Disclosed herein is an end-cap structure of an oil filter for vehicles. The end-cap includes a base cap which has a hole in a central portion thereof, and a hook cap which is installed in the hole so as to be movable upwards or downwards. In this structure, a surface of the hook cap that comes into contact with the base cap when the hook cap moves upwards is a sealing portion. When the hook cap moves downwards, the sealing state is released and a bypass is formed. According to the structure of the present invention, since the sealing portion of the end-cap can be protected from heat, the quality of the product, the productivity, the economic efficiency, etc. can be enhanced.

Abstract: A filter unit comprising an inlet (12) and an outlet (13) for a flow medium to be filtered, a first filter cartridge (14) having a first filter element, a second filter cartridge (15) having a second filter element, and a switching device (16) which allows alternating filter operation of the first or the second filter cartridge (14, 15). It is proposed that the first filter cartridge be a main cartridge (14) with a fine first filter element and the second filter cartridge be an auxiliary cartridge (15) with a coarse second filter element. The pressure loss in the auxiliary cartridge (15) is set to the same threshold value as a contaminated main cartridge (14), at which the differential pressure switch triggers an alarm such that during changing of the main filter, the alarm continuously sounds and is only switched off after changing the filtering back to a fine filtering operation.