CA1137842A - Fuel filtering device for engine - Google Patents
Fuel filtering device for engineInfo
- Publication number
- CA1137842A CA1137842A CA000354515A CA354515A CA1137842A CA 1137842 A CA1137842 A CA 1137842A CA 000354515 A CA000354515 A CA 000354515A CA 354515 A CA354515 A CA 354515A CA 1137842 A CA1137842 A CA 1137842A
- Authority
- CA
- Canada
- Prior art keywords
- fuel
- filtering device
- filter assembly
- heating member
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 102
- 238000001914 filtration Methods 0.000 title claims abstract description 55
- 238000010438 heat treatment Methods 0.000 claims abstract description 49
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 23
- 230000006872 improvement Effects 0.000 claims description 2
- 239000012777 electrically insulating material Substances 0.000 claims 1
- 239000000463 material Substances 0.000 abstract description 9
- 238000000926 separation method Methods 0.000 description 4
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- 238000010276 construction Methods 0.000 description 3
- 238000011144 upstream manufacturing Methods 0.000 description 3
- 239000012080 ambient air Substances 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 239000002283 diesel fuel Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000003570 air Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005485 electric heating Methods 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 239000003502 gasoline Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
- B01D35/18—Heating or cooling the filters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
- B01D35/14—Safety devices specially adapted for filtration; Devices for indicating clogging
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
- F02M37/22—Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines, e.g. arrangements in the feeding system
- F02M37/30—Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines, e.g. arrangements in the feeding system characterised by heating means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2200/00—Input parameters for engine control
- F02D2200/02—Input parameters for engine control the parameters being related to the engine
- F02D2200/06—Fuel or fuel supply system parameters
- F02D2200/0606—Fuel temperature
Abstract
ABSTRACT OF THE DISCLOSURE:
A fuel filtering device having a filtering element for filtering engine fuel, wherein a temperature sensing device is provided for sensing fuel temperature adjacent to the filtering element, and wherein a device is provided for heating the fuel in response to the temperature sensed by the temperature sensing device, thereby preventing clogging of the filtering element with wax like material which will be produced in the fuel under low temperature conditions.
A fuel filtering device having a filtering element for filtering engine fuel, wherein a temperature sensing device is provided for sensing fuel temperature adjacent to the filtering element, and wherein a device is provided for heating the fuel in response to the temperature sensed by the temperature sensing device, thereby preventing clogging of the filtering element with wax like material which will be produced in the fuel under low temperature conditions.
Description
1137~4~Z
BACKGROUND OF TEIE INVENTION
-This invention relates to a fuel filtering device used for a Diesel engine mounted on a motor vehicle.
In connection with a Diesel engine, the engine mounted on a motor vehicle is opera-ted on a so-called light oil which is usually highex in pour point than gasoline or petrol. Accordingly, the light oil will lose its fluidity and produce wax like material at temperatures lower than -10C, which wax like material will become attached onto the surface of a filtering element of a fuel filter to clog the filtering element.
Such clogging may also arise in the case where the fuel filter is installed at a section of the motor vehicle liable to be cooled with cold air during vehicle cruising. The filter element clogging increases the flow resistance of fuel passing through the filter element, and leads finally to a serious drawback in that the fuel will not be supplied smoothly to the engine.
SUMMARY OF THE INVENTION
In accordance with present invention, a fuel filtering device for an engine, having a filtering element, is provided with a device for sensing the temperature of fuel upstream of the filtering element, and a device is also provided for heating the fuel upstream of the filtering element in response to the temperature sensed by the sensing device. Preferably, the sensing and the heating devices form part of an electric circuit, wherein the sensing device is a temperature sensitive switch arranged to close the circuit when the temperature is below a predetermined level, and the heating device is an electric heating member arranged to heat the fuel in the fuel filtering device when supplied with electric current upon completion of the electric circuit.
An object of the present invention is to pro-vide an improved fuel filtering device for an internal ~13~7~4Z
combustion engine, by which -the engine can stably operate without causing engine running deterioration, power output shortage and engine stall.
Another object of the present invention is to provide an improved fuel fil-tering device for a Diesel engine, whereby a sufficient amount of fuel can be supplied to the engine even under low temperature condition.
A further object of the present invention is to provide an improved fuel filtering device for a Diesel engine, wherein the filtering element does not become clogged with wax like material which ordinarily would be produced in fuel under low temperature conditions.
Thus, and in accordance with the broad concept of the invention, there is provided and claimed herein a fuel filtering device for a Diesel engine, including a fuel filter assembly having therein a filtering element through which fuel flows, the improvement com-prising: a heating member contained within the filter assembly and being operable when supplied with electric current to heat fuel in the fuel filter assembly, the resistance of the heating member to the flow of electric current therethrough being directly proportional to the temperature thereof; an electric circuit operable when closed to supply electric current to the heating member;
and a temperature sensor associated with the filtering device for sens:ing the temperature of fuel therein and for closing the electric circuit when the temperature is lower than a predetermined temperature.
34~
BRIEF DESGRIPTION OF THE DRAWINGS
The features and advantages of the fuel filtering device according to the present invention will be more clearly appreciated from the following description taken in conjunction with the accompanying drawings in which like reference numerals designate like parts and elements throughout all the embodiments, and in which:
Fig. 1 is a cross-sectional view of an embodiment of a fuel filtering device in accordance with the present invention;
Fig. 2 is an enlarged section view of an essential part of the device of Fig. 1;
Fig. 3 is a circuit diagram for supplying electric current to a heating member used in the device of Fig.
1;
Fig. 4 is an enlarged sectional view of an essential part of another embodiment of the fuel filtering device in accordance with the present invention; and Fig. 5 is an enlarged sectional view of an essential part of a further embodiment of the fuel filtering device in accordance with the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION
Referring now to Figs. 1 and 2, there is shown an embodiment of a fuel filtering device used for a Diesel engine mounted on a motor vehicle (not shown), 11;~784;~
in accordance with the present invention. The fuel filtering device comprises a fuel filter assembly 1 which is constructed by an upper cover 2 to which the upper end of a filter casing 3 made of glass or steel S plate is fixed by a suitable means such as a threaded connection. A filtering element 4 including, for example, an annular pleated paper is disposed at an upper section of a space defined by the upper cover 2 and the filter casing 3, and the lower section of the space constitutes a water sump 5 in which water separated from fuel is collected. The fuel supplied under pressure from a fuel pump (not shown) is introduced through a fuel inlet 6 to a space (a dirty side) defined between the inner surface of the filter casing 3 and the outer surface of the filtering element 4, which fuel is filtered to remove dusts and the like contained therein during passage through the filtering element 4, and then flows through a space (a clean side) defined inside of the filtering element 4 and a fuel outlet 7 formed in the upper cover 2 to be supplied to the engine (not shown). It will be understood that the fuel introduced to the above-mentioned dirty side is also further introduced to the water sump 5 and held therein, so that water and impurities will be settled out by virtue of difference in specific gravity from duel so as to separate them /
/
1~'i'8~Z
from the fuel.
An annular heating member 10 including, for example, a known Positive Temperature Coefficient (PTC) heating element is disposed to be seated on the inner bottom wall surface of the filter casing 3 in a manner that the heating member is coaxial with the filter casing 3. A spring 12 is disposed between a lower oover plate 4a of the filtering element 4 and an annular spring retainer 11 mounted on the annular surface of the heatlng element 10 so as to force the filtering element to contact through a sealing member 4b to the bottom surface of the upper cover 2 and additionally force the heating member 10 to contact to the inner bottom wall surface of the filter casing 3.
An electric circuit for supplying electric current to the heating member 10 is shown in Fig. 3, which circuit is a series circuit including an electric power source 17, a manually operated switch 13 disposed, for example, at an instrument panel (not shown) of the vehicle, a temperature sensitive switch 14 such as a bimetal switch securely disposed on the upper cover 2 with a small ^~crew 14a so as to sense the temperature of the fuel filter assembly 1 or of ambient air around the filter assembly, and the heating member 10. The manually operated switch 13 is switched on by a driver of the vehicle ~. , ~378~2 when he recognizes the necessity of heating fuel, and accordingly a known timer may be additionally used to set a time period for flowing electric current to the heating member 10. The bimetal switch 14 serves as a so-called normally open switch, and arranged to be in ON position to pass the electric current therethrough when the temperature of the fuel filter assembly 1 i3 at a predetermined low level such as 0C or lower.
It will be appreciated that the temperature sensitive switch may be operated in response to the fuel temperature at a section adjacent to the filtering element 4, an engine coolant temperature, or the temperature of ambient air.
A water level detecting device 20 is provided to lS detect the level of water accumulated in the water sump 5. A;grounded terminal member 21 of the device 20 is secured to the filter ca3ing 3 in such a manner that an upwardly or vertically elongate section 21a of the terminal member is threaded into the central bottonl section of the filter casing 3. The elongate section 21a of the terminal 21 is extended upwardly by a predetermined length or distance from the inner bottom surface of the filter casing 3 as shown, and a lead 22 is disposed along the axis of the elongate section of the terminal 20 so as to protrude through the elongate - -t~ ~ -6-11;~7~4~
section 21a. The lead 22 is connected to an electric power source and covered with an insulating material to maintain an el.ectric insulation, leaving a top end 22a exposed to the space of the water sump 5. With this construction of the water level detecting device 20, when the exposed top end 22a of the lead 22 is immersed in the fuel, the electrical connection between the exposed top end 22a of the lead 22 and the grounded terminal member 21 is bloc]~ed by an insulation effect of the fuel, whereas when the exposed top end 22a detects water, the electrical connection of the exposed top end 22a and the grounded terminal 21 is established by an electrical conductive effect of water so as to cause electric current flow from the top end 22a to the grounded terminal 21. Accordingly, by sensing the electric current flowing through the lead 22, it becomes possible to detect when a predetermined amount of water has settled in the case 3. When the predetermined sedimented amount of water is thus detected, the grounded terminal member 21 is rotated to remove it from the fil-ter case 3 to drain water accumulated in the water sump 5.
Turning to the heating member 10, a lead 15 from ``.` 113~84;2 the heating member 10 is disposed within an elongate hole (no numeral) formed in the grounded terminal member 21, and drawn out of the terminal member 21 together with the lead 22. It will be understood that the leads 15 and 22 are electrically insulated from each other, and they are secured together with the grounded terminal member 21 by an electrically insulative adhesive. The reference numeral 26 denotes an O ring to provide a liquid-tight seal between the ~rounded terminal member 21 and the filter casing 3. Otherwise, the ~rounded terminal member 21 may be fixed to the filter casing 3 with an adhesive.
With the thus arranged fuel filtering device, when the ambient temperature is below 0C, the bimetal switch 14 senses such a low temperature and closes to its ON position. Additionally, when the driver closes the switch 13, electric current is supplied from the electric power source 17 through the lead 15 to the heating member 10 so that the PTC heating element is heated. Therefore, the fuel present in the filter casing 3 is heated to raise its temperature, which can maintain the fluidity of the fuel in the filter casing 3, thereby preventing the clogging of the filtering element 4 with wax like material which will be produced at low temperature.
, 4%
It :is to be noted that -the PTC heating element for heating the fuel used in the above-mentioned embodiment has a characteristic wherein as the temperature thereof increases, its resistance increases to decrease electric current flowing through the PTC heating element.
Accordingly, the heating is carried out by the heating member 10 in a manner such as to prevent the fuel from being heated excessively to a point where ignition might take place. It will be appreciated that since the heating member 10 is disposed on the bottom wall surface of the filter casing 3, the fuel in the water sump 5 is uniformly heated by virtue of convection of heated fuel, thereby preventing the fuel from being locally heated at a high temperature.
The thus raised temperature of the fuel is transmitted to the bimetal switch 14. When the trans-mitted temperature exceeds a prede-termined high temperature at which there is no fear that wax like material will be produced in the fuel, the switch 14 opens to its OFF position. Accordingly, the electric circuit for supplying electric current to the heating member 10 is opened to stop the heat generation of the heating member 10. On the contrary, when the temperature of the fuel is lowered below the predetermined low level, the heating circuit for the _ _ ` : ~137~342 heating member 10 is closed to supply électric current to the heating member 10. By repetition of such operations, the temperature of the fuel within the filter casing 3 can be kept within a certain range to maintain the fluidity of the fuel in the filter casing 3.
Fig. 4 illustrates another embodiment of the fuel filtering device according to the present invention, in which the grounded- terminal member 21 is fixed to the bottom wall of the filter case 3 by being threaded therein.
The terminal member 21 of this embodiment is in the shape of a cup and formed with an annular groove 32 within which the heating member 10 formed of gathered Positive Temperature Coef~icient heating elements is securely disposed. An annular nut 35 has at its outer periphery a threaded section 35a which is engageable with a threaded section 21b formed at the inner wall surface of the terminal member 21. When the annular nut 35 i9 tightened, the heating member lO is biased through a packing 34 so as to be secured within the annular groove 32 to form a single unit together with the terminal member 21. In this instance, the lead 22 i9 covered with an electrically insulative material 38 which is made of a plastic such as nylon, leaving the top end 22a exposed. The lead 15 from the heating member 10 is drawn out through a central through hole 1137~
3~ of the terminal member 21 together with the lead 22.
The reference numeral 37 denotes an electrically insulative adhesive to securely attach the leads 15 and 22 together to -the central section of the grounded terminal member 21.
With this arrangement, since the heating member 10 is integrally assembled with the grounded terminal member 21 of the water level detecting device 20, it is rotatable together with the grounded terminal member 21 when the grounded terminal member 21 is turned during mounting or removal from the bottom wall of the filter casing 3, which prevents damage of the lead 15 due to twist thereof, and additionally facilitates mounting and removal operations. Although the distance between the exposed top end 22a of the lead 22 and the grounded terminal member 21 is considerably larger than in the embodiment of Fig. 2, it will be appreciated that the flow of électric current therebetween will not be blocked by this greater distance.
Fig. 5 illustrates a further embodiment of the fuel filtering device in accordance with the present invention, which employs a double wall construction at the bottom section of the filter casing 3 so as to dispose the heating member 10 therebetween. The double wall construction includes a first bottom wall 44A
which `:` 113'-~34;Z
forms part of the filter casing 3, and a second bottom wall 44B which is not integral with the filter casing 3 but secured to the first bottom wall 44A. The first bottom wall 44A is formed ir.to the shape having an annular groove G within which the heating member 10 is securely disposed under the action of the second bottom wall 44B. A cylindrical nut 46 is provided with a threaded section (no numeral) at its inner cylindrical surface which section engages with a threaded section of the upwardly elongage section 21a of the grounded terminal member 21 so that the terminal member is fixed onto the bottom wall section of the filter casing 3.
With this arrangement, fuel in the filter casing 3 is indirectly heated through the first bottom wall 15 44A by the heating member lO, and therefore an ignition of fuel in the filter case 3 i~ completely prevented, obtaining a secure electrical insulation of the heating member lO.
While the heating member in the afore-mentioned embodiments has been shown and described to be disposed only in the fuel filter assembly 1 in which a fuel filter section is incorporated with the a water separation section, it will be seen that the heating member may be disposed in the fuel filter section in a fuel filtering device of the type wherein the fuel filter section is 113-~B4Z
disposed separately and independently from the water separation section, and otherwise may be disposed in the water separation section in case where the water separation section is located upstream of the fuel filter section.
Although the explanation of the present invention has been made on the fuel filtering device for light oil such as for example Diesel fuel, it will be understood that the present invention may be applicable to fuel filtering devices for other fuels having a high pour point, such as light oil mixed with kerosine. Additionally, the present invention may be also applicable to other fuel filtering devices for filtering high pour point fuels other than Diesel fuel.
15 As will be appreciated from the above, according to the present invention, a condition under which wax like material is produced due to low temperature in a fuel filtering device can be predicted, and then fuel in the filtering device is heated to maintain its suitable fluidity so as to prevent clogging of a filter element with the wax like material. Accordingly, a required amount of fuel can be effectively supplied to an engine, thereby preventing engine running deterioration, power output shortage, and engine ~tall.
. ~ 13-
BACKGROUND OF TEIE INVENTION
-This invention relates to a fuel filtering device used for a Diesel engine mounted on a motor vehicle.
In connection with a Diesel engine, the engine mounted on a motor vehicle is opera-ted on a so-called light oil which is usually highex in pour point than gasoline or petrol. Accordingly, the light oil will lose its fluidity and produce wax like material at temperatures lower than -10C, which wax like material will become attached onto the surface of a filtering element of a fuel filter to clog the filtering element.
Such clogging may also arise in the case where the fuel filter is installed at a section of the motor vehicle liable to be cooled with cold air during vehicle cruising. The filter element clogging increases the flow resistance of fuel passing through the filter element, and leads finally to a serious drawback in that the fuel will not be supplied smoothly to the engine.
SUMMARY OF THE INVENTION
In accordance with present invention, a fuel filtering device for an engine, having a filtering element, is provided with a device for sensing the temperature of fuel upstream of the filtering element, and a device is also provided for heating the fuel upstream of the filtering element in response to the temperature sensed by the sensing device. Preferably, the sensing and the heating devices form part of an electric circuit, wherein the sensing device is a temperature sensitive switch arranged to close the circuit when the temperature is below a predetermined level, and the heating device is an electric heating member arranged to heat the fuel in the fuel filtering device when supplied with electric current upon completion of the electric circuit.
An object of the present invention is to pro-vide an improved fuel filtering device for an internal ~13~7~4Z
combustion engine, by which -the engine can stably operate without causing engine running deterioration, power output shortage and engine stall.
Another object of the present invention is to provide an improved fuel fil-tering device for a Diesel engine, whereby a sufficient amount of fuel can be supplied to the engine even under low temperature condition.
A further object of the present invention is to provide an improved fuel filtering device for a Diesel engine, wherein the filtering element does not become clogged with wax like material which ordinarily would be produced in fuel under low temperature conditions.
Thus, and in accordance with the broad concept of the invention, there is provided and claimed herein a fuel filtering device for a Diesel engine, including a fuel filter assembly having therein a filtering element through which fuel flows, the improvement com-prising: a heating member contained within the filter assembly and being operable when supplied with electric current to heat fuel in the fuel filter assembly, the resistance of the heating member to the flow of electric current therethrough being directly proportional to the temperature thereof; an electric circuit operable when closed to supply electric current to the heating member;
and a temperature sensor associated with the filtering device for sens:ing the temperature of fuel therein and for closing the electric circuit when the temperature is lower than a predetermined temperature.
34~
BRIEF DESGRIPTION OF THE DRAWINGS
The features and advantages of the fuel filtering device according to the present invention will be more clearly appreciated from the following description taken in conjunction with the accompanying drawings in which like reference numerals designate like parts and elements throughout all the embodiments, and in which:
Fig. 1 is a cross-sectional view of an embodiment of a fuel filtering device in accordance with the present invention;
Fig. 2 is an enlarged section view of an essential part of the device of Fig. 1;
Fig. 3 is a circuit diagram for supplying electric current to a heating member used in the device of Fig.
1;
Fig. 4 is an enlarged sectional view of an essential part of another embodiment of the fuel filtering device in accordance with the present invention; and Fig. 5 is an enlarged sectional view of an essential part of a further embodiment of the fuel filtering device in accordance with the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION
Referring now to Figs. 1 and 2, there is shown an embodiment of a fuel filtering device used for a Diesel engine mounted on a motor vehicle (not shown), 11;~784;~
in accordance with the present invention. The fuel filtering device comprises a fuel filter assembly 1 which is constructed by an upper cover 2 to which the upper end of a filter casing 3 made of glass or steel S plate is fixed by a suitable means such as a threaded connection. A filtering element 4 including, for example, an annular pleated paper is disposed at an upper section of a space defined by the upper cover 2 and the filter casing 3, and the lower section of the space constitutes a water sump 5 in which water separated from fuel is collected. The fuel supplied under pressure from a fuel pump (not shown) is introduced through a fuel inlet 6 to a space (a dirty side) defined between the inner surface of the filter casing 3 and the outer surface of the filtering element 4, which fuel is filtered to remove dusts and the like contained therein during passage through the filtering element 4, and then flows through a space (a clean side) defined inside of the filtering element 4 and a fuel outlet 7 formed in the upper cover 2 to be supplied to the engine (not shown). It will be understood that the fuel introduced to the above-mentioned dirty side is also further introduced to the water sump 5 and held therein, so that water and impurities will be settled out by virtue of difference in specific gravity from duel so as to separate them /
/
1~'i'8~Z
from the fuel.
An annular heating member 10 including, for example, a known Positive Temperature Coefficient (PTC) heating element is disposed to be seated on the inner bottom wall surface of the filter casing 3 in a manner that the heating member is coaxial with the filter casing 3. A spring 12 is disposed between a lower oover plate 4a of the filtering element 4 and an annular spring retainer 11 mounted on the annular surface of the heatlng element 10 so as to force the filtering element to contact through a sealing member 4b to the bottom surface of the upper cover 2 and additionally force the heating member 10 to contact to the inner bottom wall surface of the filter casing 3.
An electric circuit for supplying electric current to the heating member 10 is shown in Fig. 3, which circuit is a series circuit including an electric power source 17, a manually operated switch 13 disposed, for example, at an instrument panel (not shown) of the vehicle, a temperature sensitive switch 14 such as a bimetal switch securely disposed on the upper cover 2 with a small ^~crew 14a so as to sense the temperature of the fuel filter assembly 1 or of ambient air around the filter assembly, and the heating member 10. The manually operated switch 13 is switched on by a driver of the vehicle ~. , ~378~2 when he recognizes the necessity of heating fuel, and accordingly a known timer may be additionally used to set a time period for flowing electric current to the heating member 10. The bimetal switch 14 serves as a so-called normally open switch, and arranged to be in ON position to pass the electric current therethrough when the temperature of the fuel filter assembly 1 i3 at a predetermined low level such as 0C or lower.
It will be appreciated that the temperature sensitive switch may be operated in response to the fuel temperature at a section adjacent to the filtering element 4, an engine coolant temperature, or the temperature of ambient air.
A water level detecting device 20 is provided to lS detect the level of water accumulated in the water sump 5. A;grounded terminal member 21 of the device 20 is secured to the filter ca3ing 3 in such a manner that an upwardly or vertically elongate section 21a of the terminal member is threaded into the central bottonl section of the filter casing 3. The elongate section 21a of the terminal 21 is extended upwardly by a predetermined length or distance from the inner bottom surface of the filter casing 3 as shown, and a lead 22 is disposed along the axis of the elongate section of the terminal 20 so as to protrude through the elongate - -t~ ~ -6-11;~7~4~
section 21a. The lead 22 is connected to an electric power source and covered with an insulating material to maintain an el.ectric insulation, leaving a top end 22a exposed to the space of the water sump 5. With this construction of the water level detecting device 20, when the exposed top end 22a of the lead 22 is immersed in the fuel, the electrical connection between the exposed top end 22a of the lead 22 and the grounded terminal member 21 is bloc]~ed by an insulation effect of the fuel, whereas when the exposed top end 22a detects water, the electrical connection of the exposed top end 22a and the grounded terminal 21 is established by an electrical conductive effect of water so as to cause electric current flow from the top end 22a to the grounded terminal 21. Accordingly, by sensing the electric current flowing through the lead 22, it becomes possible to detect when a predetermined amount of water has settled in the case 3. When the predetermined sedimented amount of water is thus detected, the grounded terminal member 21 is rotated to remove it from the fil-ter case 3 to drain water accumulated in the water sump 5.
Turning to the heating member 10, a lead 15 from ``.` 113~84;2 the heating member 10 is disposed within an elongate hole (no numeral) formed in the grounded terminal member 21, and drawn out of the terminal member 21 together with the lead 22. It will be understood that the leads 15 and 22 are electrically insulated from each other, and they are secured together with the grounded terminal member 21 by an electrically insulative adhesive. The reference numeral 26 denotes an O ring to provide a liquid-tight seal between the ~rounded terminal member 21 and the filter casing 3. Otherwise, the ~rounded terminal member 21 may be fixed to the filter casing 3 with an adhesive.
With the thus arranged fuel filtering device, when the ambient temperature is below 0C, the bimetal switch 14 senses such a low temperature and closes to its ON position. Additionally, when the driver closes the switch 13, electric current is supplied from the electric power source 17 through the lead 15 to the heating member 10 so that the PTC heating element is heated. Therefore, the fuel present in the filter casing 3 is heated to raise its temperature, which can maintain the fluidity of the fuel in the filter casing 3, thereby preventing the clogging of the filtering element 4 with wax like material which will be produced at low temperature.
, 4%
It :is to be noted that -the PTC heating element for heating the fuel used in the above-mentioned embodiment has a characteristic wherein as the temperature thereof increases, its resistance increases to decrease electric current flowing through the PTC heating element.
Accordingly, the heating is carried out by the heating member 10 in a manner such as to prevent the fuel from being heated excessively to a point where ignition might take place. It will be appreciated that since the heating member 10 is disposed on the bottom wall surface of the filter casing 3, the fuel in the water sump 5 is uniformly heated by virtue of convection of heated fuel, thereby preventing the fuel from being locally heated at a high temperature.
The thus raised temperature of the fuel is transmitted to the bimetal switch 14. When the trans-mitted temperature exceeds a prede-termined high temperature at which there is no fear that wax like material will be produced in the fuel, the switch 14 opens to its OFF position. Accordingly, the electric circuit for supplying electric current to the heating member 10 is opened to stop the heat generation of the heating member 10. On the contrary, when the temperature of the fuel is lowered below the predetermined low level, the heating circuit for the _ _ ` : ~137~342 heating member 10 is closed to supply électric current to the heating member 10. By repetition of such operations, the temperature of the fuel within the filter casing 3 can be kept within a certain range to maintain the fluidity of the fuel in the filter casing 3.
Fig. 4 illustrates another embodiment of the fuel filtering device according to the present invention, in which the grounded- terminal member 21 is fixed to the bottom wall of the filter case 3 by being threaded therein.
The terminal member 21 of this embodiment is in the shape of a cup and formed with an annular groove 32 within which the heating member 10 formed of gathered Positive Temperature Coef~icient heating elements is securely disposed. An annular nut 35 has at its outer periphery a threaded section 35a which is engageable with a threaded section 21b formed at the inner wall surface of the terminal member 21. When the annular nut 35 i9 tightened, the heating member lO is biased through a packing 34 so as to be secured within the annular groove 32 to form a single unit together with the terminal member 21. In this instance, the lead 22 i9 covered with an electrically insulative material 38 which is made of a plastic such as nylon, leaving the top end 22a exposed. The lead 15 from the heating member 10 is drawn out through a central through hole 1137~
3~ of the terminal member 21 together with the lead 22.
The reference numeral 37 denotes an electrically insulative adhesive to securely attach the leads 15 and 22 together to -the central section of the grounded terminal member 21.
With this arrangement, since the heating member 10 is integrally assembled with the grounded terminal member 21 of the water level detecting device 20, it is rotatable together with the grounded terminal member 21 when the grounded terminal member 21 is turned during mounting or removal from the bottom wall of the filter casing 3, which prevents damage of the lead 15 due to twist thereof, and additionally facilitates mounting and removal operations. Although the distance between the exposed top end 22a of the lead 22 and the grounded terminal member 21 is considerably larger than in the embodiment of Fig. 2, it will be appreciated that the flow of électric current therebetween will not be blocked by this greater distance.
Fig. 5 illustrates a further embodiment of the fuel filtering device in accordance with the present invention, which employs a double wall construction at the bottom section of the filter casing 3 so as to dispose the heating member 10 therebetween. The double wall construction includes a first bottom wall 44A
which `:` 113'-~34;Z
forms part of the filter casing 3, and a second bottom wall 44B which is not integral with the filter casing 3 but secured to the first bottom wall 44A. The first bottom wall 44A is formed ir.to the shape having an annular groove G within which the heating member 10 is securely disposed under the action of the second bottom wall 44B. A cylindrical nut 46 is provided with a threaded section (no numeral) at its inner cylindrical surface which section engages with a threaded section of the upwardly elongage section 21a of the grounded terminal member 21 so that the terminal member is fixed onto the bottom wall section of the filter casing 3.
With this arrangement, fuel in the filter casing 3 is indirectly heated through the first bottom wall 15 44A by the heating member lO, and therefore an ignition of fuel in the filter case 3 i~ completely prevented, obtaining a secure electrical insulation of the heating member lO.
While the heating member in the afore-mentioned embodiments has been shown and described to be disposed only in the fuel filter assembly 1 in which a fuel filter section is incorporated with the a water separation section, it will be seen that the heating member may be disposed in the fuel filter section in a fuel filtering device of the type wherein the fuel filter section is 113-~B4Z
disposed separately and independently from the water separation section, and otherwise may be disposed in the water separation section in case where the water separation section is located upstream of the fuel filter section.
Although the explanation of the present invention has been made on the fuel filtering device for light oil such as for example Diesel fuel, it will be understood that the present invention may be applicable to fuel filtering devices for other fuels having a high pour point, such as light oil mixed with kerosine. Additionally, the present invention may be also applicable to other fuel filtering devices for filtering high pour point fuels other than Diesel fuel.
15 As will be appreciated from the above, according to the present invention, a condition under which wax like material is produced due to low temperature in a fuel filtering device can be predicted, and then fuel in the filtering device is heated to maintain its suitable fluidity so as to prevent clogging of a filter element with the wax like material. Accordingly, a required amount of fuel can be effectively supplied to an engine, thereby preventing engine running deterioration, power output shortage, and engine ~tall.
. ~ 13-
Claims (8)
1. A fuel filtering device for a Diesel engine, including a fuel filter assembly having therein a filtering element through which fuel flows, the improve-ment comprising: a heating member contained within said filter assembly and being operable when supplied with electric current to heat fuel in the fuel filter assembly, the resistance of said heating member to the flow of electric current therethrough being directly proportional to the temperature thereof; an electric circuit operable when closed to supply electric current to said heating member; and a temperature sensor associated with said filtering device for sensing the temperature of fuel therein and for closing said electric circuit when said temperature is lower than a pre-determined temperature.
2. A fuel filtering device as claimed in claim 1, in which said heating member is disposed at the bottom section of the fuel filter assembly to heat the fuel at the bottom section of the fuel filter assembly.
3. A fuel filtering device as claimed in claim 2, in which said heating member is disposed within a casing of the fuel filter assembly so as to directly heat the fuel in the fuel filter assembly.
4. A fuel filtering device as claimed in claim 2, in which said heating member is disposed outside of a casing of the fuel filter assembly so as to indirectly heat the fuel in the fuel filter assembly through the wall of the casing.
5. A fuel filtering device as claimed in claim 1, further comprising means for detecting a pre-determined amount of water accumulated in a casing of the fuel filter assembly.
6. A fuel filtering device as claimed in claim 5, in which said detecting means includes a terminal member which is grounded and secured at the bottom section of said casing, and an electrically conductive lead connected to an electric power source and vertically elongated from the bottom section of said casing by a distance corresponding to said predetermined amount of accumulated water, at least top end of said lead being exposed without being covered with an electrically insulating material.
7. A fuel filtering device as claimed in claim 6, in which said terminal member is detachable from the bottom section of said casing.
8. A fuel filtering device as claimed in claim 7, in which said heating member is incorporated with said terminal member to form a single unit.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1979084145U JPS5939179Y2 (en) | 1979-06-21 | 1979-06-21 | Diesel engine fuel filter device |
| JP54-84145 | 1979-06-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1137842A true CA1137842A (en) | 1982-12-21 |
Family
ID=13822324
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000354515A Expired CA1137842A (en) | 1979-06-21 | 1980-06-20 | Fuel filtering device for engine |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US4321136A (en) |
| JP (1) | JPS5939179Y2 (en) |
| CA (1) | CA1137842A (en) |
Families Citing this family (46)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2487432A1 (en) * | 1980-07-24 | 1982-01-29 | Diry Andre | FILTER FOR SIMULTANEOUS FUEL FILTRATION AND HEATING |
| JPS5756656A (en) * | 1980-08-04 | 1982-04-05 | Technar Inc | Fuel heater |
| USRE34166E (en) * | 1980-09-19 | 1993-01-26 | Davco Manufacturing Corporation | Fuel processor apparatus for diesel engine powered vehicles |
| US4387691A (en) * | 1980-11-07 | 1983-06-14 | Texas Instruments Incorporated | Diesel fuel filter system |
| US4600825A (en) * | 1981-06-03 | 1986-07-15 | Walter Blazejovsky | Electrically heated diesel engine fuel conveying system |
| US4495069A (en) * | 1981-07-27 | 1985-01-22 | Davco, Inc. | Drain system for fuel processor apparatus |
| US4406785A (en) * | 1981-12-24 | 1983-09-27 | Gte Products Corporation | Diesel fuel heater |
| US4515690A (en) * | 1982-08-06 | 1985-05-07 | Nissan Motor Company, Limited | Fuel supply system for diesel engines |
| US4470301A (en) * | 1982-09-22 | 1984-09-11 | Fram Corporation | Probe and drain assembly for fuel oil/water separator |
| WO1984002246A1 (en) * | 1982-11-22 | 1984-06-07 | Ford Motor Canada | Electric heater assembly for heating a diesel engine fuel filter |
| US4522166A (en) * | 1982-12-07 | 1985-06-11 | Ilkka Toivio | Device for the improving of the starting of an engine |
| US4539109A (en) * | 1983-02-01 | 1985-09-03 | Davco Manufacturing Corporation | Drain system for fuel processor apparatus |
| JPS59190462A (en) * | 1983-04-12 | 1984-10-29 | Nippon Denso Co Ltd | Fuel heating type fuel filter |
| US4585924A (en) * | 1983-08-08 | 1986-04-29 | Ford Motor Company | Self-contained electric diesel engine fuel filter assembly heater |
| DE3421815A1 (en) * | 1983-08-08 | 1985-03-21 | Ford-Werke AG, 5000 Köln | Electrical heating device for diesel fuel |
| US4680110A (en) * | 1984-01-23 | 1987-07-14 | Davco Manufacturing Corporation | Filter block mounted fuel processor apparatus |
| IT8452929V0 (en) * | 1984-01-31 | 1984-01-31 | Etd Termodiesel Di Scarpa Pier | HEATER DEVICE APPLICABLE TO A FUEL FILTER |
| US4547287A (en) * | 1984-03-07 | 1985-10-15 | Champion Laboratories, Inc. | Thermostatically controlled pack hold-down assembly |
| US4500425A (en) * | 1984-06-13 | 1985-02-19 | Allied Corporation | Pump valve for liquid separator |
| US4861966A (en) * | 1985-10-15 | 1989-08-29 | Raychem Corporation | Method and apparatus for electrically heating diesel fuel utilizing a PTC polymer heating element |
| JPS62186940A (en) * | 1986-02-10 | 1987-08-15 | Kanegafuchi Chem Ind Co Ltd | Adsorbent for lipoprotein |
| JPS62277115A (en) * | 1986-02-25 | 1987-12-02 | Nippon Denso Co Ltd | Heating system for fuel |
| FR2594708B1 (en) * | 1986-02-25 | 1990-05-04 | Nippon Denso Co | FUEL FILTERING DEVICE OF THE FUEL HEATING TYPE |
| US4637351A (en) * | 1986-03-28 | 1987-01-20 | Ford Motor Company | System for removal of water from diesel fuel systems |
| US4944343A (en) * | 1987-08-29 | 1990-07-31 | Mueller Fritz | Apparatus for heating fuel |
| US5249623A (en) * | 1987-08-29 | 1993-10-05 | Mueller Fritz | Rubber heat exchanger |
| AU2906189A (en) * | 1987-12-18 | 1989-07-19 | Houston Winn | Fuel filter and separator |
| DE3829126C1 (en) * | 1988-08-27 | 1989-10-19 | Knecht Filterwerke Gmbh, 7000 Stuttgart, De | |
| US5143608A (en) * | 1990-08-31 | 1992-09-01 | Morf, Inc. | System of separation from a liquid |
| US5879543A (en) * | 1994-04-13 | 1999-03-09 | Amini; Bijan | Filter and dehydrator apparatus with threaded collar |
| US5855772A (en) * | 1996-11-01 | 1999-01-05 | Fleetguard, Inc. | Fuel filter and water separator apparatus with heater |
| US5981910A (en) * | 1997-05-06 | 1999-11-09 | Williams; Wayne | Heated cover for a fuel filter |
| US5846417A (en) * | 1997-07-21 | 1998-12-08 | Fleetguard, Inc. | Self closing filter centerpost |
| US6171492B1 (en) | 1999-02-04 | 2001-01-09 | Purolator Products Company | Filter for liquid fuel |
| US6817754B2 (en) | 2002-04-16 | 2004-11-16 | Charles Tsang | Fuel freezing point monitoring device |
| ITRE20020094A1 (en) * | 2002-12-03 | 2004-06-04 | Ufi Universal Filter Internat S P A | FUEL FILTER FOR DIRECT INJECTION DIESEL ENGINES |
| DE102004059062B4 (en) * | 2004-12-07 | 2006-09-14 | Mann + Hummel Gmbh | Fuel filter system, in particular for motor vehicles and method for its operation |
| DE102005011221A1 (en) * | 2005-03-11 | 2006-09-14 | Mann+Hummel Gmbh | Liquid filter-heat exchanger unit |
| ITRE20050075A1 (en) * | 2005-07-06 | 2007-01-07 | Ufi Filters Spa | FILTERING UNIT FOR FUEL FOR DIESEL ENGINES |
| DE102009016601A1 (en) | 2009-04-08 | 2010-10-21 | Mann + Hummel Gmbh | Filter device for fluids, in particular for fuels |
| JP2012167559A (en) * | 2011-02-10 | 2012-09-06 | Denso Corp | Fuel injection device |
| JP2014231763A (en) * | 2013-05-28 | 2014-12-11 | 京三電機株式会社 | Fuel supply device |
| SE537174C2 (en) * | 2013-06-13 | 2015-02-24 | Scania Cv Ab | Combustion engine fuel system, internal combustion engine with such a fuel system, vehicles with such a fuel system and a method for reducing the risk of malfunctioning fuel caused by paraffin fuel in a fuel system |
| US20150108049A1 (en) * | 2013-10-18 | 2015-04-23 | I-Sin Peng | Water-filtration detecting device of water filter |
| IT201600123932A1 (en) * | 2016-12-06 | 2018-06-06 | Bosch Gmbh Robert | APPARATUS AND METHOD FOR UNINSTALLING A FILTER OF A DIESEL OIL PUMPING GROUP TO AN INTERNAL COMBUSTION ENGINE |
| IT201600123942A1 (en) * | 2016-12-06 | 2018-06-06 | Bosch Gmbh Robert | GROUP AND METHOD TO CLEAN A FILTER OF A DIESEL OIL PUMPING GROUP TO AN INTERNAL COMBUSTION ENGINE |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2218715A (en) * | 1937-12-17 | 1940-10-22 | Transp Appliances Inc | Oil cleaner and temperature regulator |
| US3235084A (en) * | 1962-01-30 | 1966-02-15 | Stewart Warner Corp | Fuel filter with heating unit |
| US3568835A (en) * | 1968-07-01 | 1971-03-09 | Int Marketing Corp The | Liquid separator and filter unit |
| US4091265A (en) * | 1975-08-06 | 1978-05-23 | Racor Industries, Inc. | Fuel filter heating assembly |
| DE2760241C2 (en) * | 1976-09-09 | 1991-01-24 | Texas Instruments Inc | Electric heater |
-
1979
- 1979-06-21 JP JP1979084145U patent/JPS5939179Y2/en not_active Expired
-
1980
- 1980-06-16 US US06/160,058 patent/US4321136A/en not_active Expired - Lifetime
- 1980-06-20 CA CA000354515A patent/CA1137842A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5939179Y2 (en) | 1984-10-31 |
| US4321136A (en) | 1982-03-23 |
| JPS564653U (en) | 1981-01-16 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |