Fuel filter for diesel engine
A fuel filter for a diesel engine may include an upper cover forming inflow and outflow passages of diesel fuel, a housing integrally mounted in a vehicle body, coupled to the upper cover and housing a filter assembly, and a body penetrating a central portion of the filter assembly, disposed between the upper cover and the filter assembly and integrally forming the upper cover, a heater assembly, and a moisture sensor, in which the heater assembly may be configured to selectively operate according to a detection signal of a fuel temperature sensor that is provided in the engine body.
1. A fuel filter for a diesel engine, the fuel filter comprising:
an upper cover forming inflow and outflow passages of diesel fuel;
a housing integrally mounted in a vehicle body through a mounting bracket, coupled to the upper cover, and housing a filter assembly;
a body forming a moisture drain passage that penetrates a central portion of the filter assembly, disposed between the upper cover and the filter assembly, and connected to an inner lower portion of the housing;
a heater assembly installed at an inside of an upper end portion of the body;
a moisture sensor installed in the moisture drain passage of the body and configured to detect a water level of moisture that is separated from diesel fuel; and
a moisture exhaust portion that is provided in an upper end portion of the body in order to discharge moisture that is injected into the moisture drain passage and that penetrates the upper cover,
wherein the body comprises:
a head portion located between the upper cover and the filter assembly and fixed to an inner wall surface of the housing; and
a stem portion integrally connected to the head portion, penetrating the central portion of the filter assembly, and forming the moisture drain passage,
wherein an outer circumferential portion of a reinforcing plate that reinforces rigidity of the upper cover is bonded to a lower surface of the upper cover to form a connecting flow channel positioned between the reinforcing plate and the lower surface of the upper cover,
wherein a fuel exhaust nipple to form the outflow passage for discharging the diesel fuel from which moisture and a foreign substance are removed while passing through the filter assembly is installed in the upper cover,
wherein an exhaust flow channel for discharging the diesel fuel from which the moisture and the foreign substance are removed while passing through the filter assembly is formed between the stem portion and the reinforcing plate, and
wherein the connection flow channel connects the exhaust flow channel and the fuel exhaust nipple.
2. The fuel filter of claim 1 , wherein the body has a single module form and integrally forms the upper cover, the heater assembly, the moisture sensor, and the moisture exhaust portion.
3. The fuel filter of claim 1 , wherein the heater assembly comprises:
a pair of heat releasing plates installed at a predetermined gap from a lower surface of the head portion; and
a plurality of Positive Temperature Coefficient (PTC) heaters fixedly installed between the pair of heat releasing plates.
4. The fuel filter of claim 3 ,
wherein a predetermined heating space is formed between a lower surface of the head portion and the heat releasing plate, and
wherein the heating space is connected to a space between an inner wall surface of the housing and the filter assembly through at least one penetration hole provided in the heat releasing plate.
5. The fuel filter of claim 4 ,
wherein a fuel inflow nipple connected to the heating space and configured to inject diesel fuel into the filter assembly to form the inflow passage, is installed in the upper cover, and
wherein the fuel exhaust nipple configured to discharge diesel fuel from which moisture and a foreign substance are removed while passing through the filter assembly, is installed in the upper cover.
6. The fuel filter of claim 1 , wherein the reinforcing plate comprises a penetrating portion protruded from a center thereof in a downward direction, coupled to the upper surface of the head portion, and connected to the exhaust flow channel of the stem portion.
7. The fuel filter of claim 6 ,
wherein the reinforcing plate forms a groove of a predetermined area that is inwardly recessed in a downward direction and that is connected to the penetrating portion, and
wherein the groove is formed as the connection flow channel that connects the exhaust flow channel and the fuel exhaust nipple between the upper cover and the reinforcing plate.
8. The fuel filter of claim 1 , wherein the moisture sensor comprises a pair of moisture detection pins that are insert-injected to the stem portion and that are disposed at the moisture drain passage.
9. The fuel filter of claim 8 , wherein a moisture detection circuit that is electrically connected to the moisture detection pin is installed at an upper surface of the upper cover.
10. The fuel filter of claim 1 , wherein the moisture exhaust portion comprises:
a moisture exhaust nipple that penetrates the upper cover and that is connected to the moisture drain passage of the stem portion; and
a moisture drain plug installed in the moisture exhaust nipple.
11. The fuel filter of claim 10 , wherein the drain plug comprises a plug body that is screw-coupled to the moisture exhaust nipple and that selectively opens and closes the moisture drain passage, and a screw thread, formed at a portion of an outer circumferential surface of the plug body, and a drain hole, connected from a remaining outer circumferential surface of the plug body to an upper surface of the plug body, are formed at the plug body.