Liquid filter having a drainage valve

A liquid filter comprising:

• a filter housing arranged upright in operation, and
• a hollow-cylindrical filter insert accommodated therein so as to be exchangeable,
• the filter housing having a dirty liquid feed, a clean liquid outlet and a liquid drainage channel, and being closed in operation by means of a detachable top-side cover,
• a drainage valve being arranged in the drainage channel, the valve body of which is displaceable in an axially limited manner in the drainage channel between a closing position closing the channel and an open position clearing it,
• the valve body being detachably attached to one of the cover and the filter insert,
• wherein, when the cover is mounted on the filter housing, said cover presses the valve body one of directly and via the filter insert into the closing position closing the drainage channel, and
• wherein, when the cover is removed from the filter housing in the axial direction thereof, the valve body is first able to be carried along by the cover or by the filter insert in the opening direction to its open position, and then is detachable from the one of the cover and the filter insert and is retainable in its open position by means of a holding element,
• the holding element being formed by at least one spring element which automatically expands into the opening position of the valve body by its spring force, and comes into attachment to a spring element restraint holding the valve body in its open position, and which by exertion of a force contracts, and thus a displacement of the valve body in the closing direction is brought about, releasing engagement with the spring element restraint.

A liquid filter comprising:

• a filter housing arranged upright in operation, and
• a hollow-cylindrical filter insert accommodated therein so as to be exchangeable,
• the filter housing having a dirty liquid feed, a clean liquid outlet and a liquid drainage channel, and being closed in operation by means of a detachable top-side cover,
• a drainage valve being arranged in the drainage channel,
• a valve body of the drainage valve being displaceable in an axially limited manner in the drainage channel between a closing position closing the channel and an open position clearing it,
• wherein when the cover is mounted on the filter housing, the valve body is pressed into the closing position closing the drainage channel, and wherein when removing the cover from the filter housing in the axial direction thereof, the valve body is carried along in the opening direction by one of the cover and the filter insert,
• a filter bypass valve being arranged in the filter housing having an axially displaceable valve body, the closing direction of which points towards the cover, and
• a compression spring being arranged between the valve body of the drainage valve and the valve body of the filter bypass valve, which compression spring preloads both valve bodies at the same time in their respective closing direction when the cover is mounted on the housing.