GB2555448A

GB2555448A - Fuel filter with water sensor, and sensor therefor

Info

Publication number: GB2555448A
Application number: GB1618242.0A
Authority: GB
Inventors: Andrew Darley James; David Pearson Malcolm; Kenneth Batchelor James
Original assignee: Perkins Engines Co Ltd
Current assignee: Perkins Engines Co Ltd
Priority date: 2016-10-28
Filing date: 2016-10-28
Publication date: 2018-05-02
Anticipated expiration: 2036-10-28
Also published as: CN108005823A; CN108005823B; GB201618242D0; GB2555448B

Abstract

A sensor 142 for a combustion engine fuel filter 100 having a body 102 defining a cavity 109, configured to house a filter assembly 110 within the cavity, the cavity including a bowl 128 defined between a base 104 of the body and the filter assembly. The sensor comprises a pair of conductive elements (154, 156, Fig 3) configured to traverse the bowl in use and spacing means 164 configured to hold the conductive elements spaced from the base and spaced from the filter assembly. The sensor may be used for sensing the presence of water in the bowl 128 of a fuel filter and the conductive elements 154, 156 traversing the bowl 128 may improve the ability of the sensor 142 to sense the presence of water in the bowl 128 when the fuel filter 100 is tilted.

Description

(54) Title of the Invention: Fuel filter with water sensor, and sensor therefor Abstract Title: Fuel filter (57) A sensor 142 for a combustion engine fuel filter 100 having a body 102 defining a cavity 109, configured to house a filter assembly 110 within the cavity, the cavity including a bowl 128 defined between a base 104 of the body and the filter assembly. The sensor comprises a pair of conductive elements (154, 156, Fig 3) configured to traverse the bowl in use and spacing means 164 configured to hold the conductive elements spaced from the base and spaced from the filter assembly. The sensor may be used for sensing the presence of water in the bowl 128 of a fuel filter and the conductive elements 154, 156 traversing the bowl 128 may improve the ability of the sensor 142 to sense the presence of water in the bowl 128 when the fuel filter 100 is tilted.

124

1/4

100

124

2/4

100

124

136

138

142

3/4

160

200

4/4

202

204

Detecting a change in resistance between the pair of conductive elements

206

-1Title

FUEL FILTER WITH WATER SENSOR, AND SENSOR THEREFOR

Technical Field [001] The present disclosure generally relates to a fuel filter having a water sensor, and to a sensor therefor.

Background [002] This disclosure relates generally to a fuel filter, preferably for use on a vehicle. Despite precautions that may be taken, water can enter into a vehicle’s fuel tank and mix with the stored fuel. For instance, it may be necessary to add fuel to the fuel tank in rainy weather. Condensation also adds moisture to the fuel as the fuel tank is warmed and cooled with temperature fluctuations. Fuel added to the vehicle’s fuel tank may also contain some water, especially where fuel is being added from an outdoor storage vessel as is common practice in work sites.

[003] During subsequent operation of the vehicle the water and fuel are agitated so that a fuel and water mixture is fed to the engine's fuel system. This causes engine operating problems and excessive wear of moving parts, particularly in the fuel system. In addition, the water in the tank and associated passages produces rust, which in turn is fed into the fuel supply system and results in clogging and/or greater rates of engine wear.

[004] It is especially undesirable for water in the fuel to be drawn into a diesel engine fuel system, as the system relies on the diesel for lubrication of the moving parts. If water gets into a moving part which requires constant lubrication, such as an injector valve, it will quickly cause overheating and unnecessary wear.

[005] Some fuel filters, especially those found on diesel engines, have a bowl-like section at the bottom in which water can collect (as water is more dense than diesel). The water can then be drained off by opening a valve in the bottom of the bowl and letting it run out. Many fuel filters contain a water sensor to signal to the engine control unit or directly to the driver if the water reaches a warning level.

[006] US patent 9,729,780 discloses a filter system for filtering fuel having a waterin-fuel (WIF) sensor in which two elongate metal pins extend through the body of the WIF sensor. When sufficient water has collected in the filter system it will permit electrical

-2conduction between the pins that is detected and altered to an operator. The pins also form a connection with conductive material provided on a bottom end cap of a filter element, so that the WIF sensor may also be used to detect whether a qualified filter element is installed.

Summary of the Disclosure [007] One difficulty that can arise with some fuel filters having a WIF sensor occurs when then fuel filter is tilted, for instance when a vehicle travels along a slope or over uneven terrain. When the fuel filter is tilted, it is possible the WIF sensor may be elevated with respect to water present in the filter. Thus the quantity of water required to be present in the fuel filter for the WIF sensor to detect it may vary as a function of the degree to which the filter is tilted and the direction in which it is tilted. In some instances it may be possible for water in the fuel filter to come into contact with the filter media without the water being detected by the WIF sensor if the fuel filter is tilted in certain directions. Fuel filters with WIF sensors located away from a central axis of the fuel filter are particularly susceptible to this occurring. Water may then pass through the filter media, out of the fuel filter and into the engine, which is undesirable.

[008] In one aspect of the present disclosure, there is provided a fuel filter for a combustion engine, comprising:

a body defining a cavity, the body including a base, the body configured to house a filter media within the cavity;

the cavity including a bowl defined between the base of the body and an end of the filter media;

a sensor comprising a pair of conductive elements traversing the bowl, the conductive elements held spaced from the base and spaced from the end of the filter media.

[009] Preferably, the conductive elements traverse the bowl adjacent an inner wall of the bowl.

[010] Preferably, the conductive elements are formed on an inner wall of the bowl.

[Oil] Preferably, the conductive elements are formed integral with a substrate.

[012] Preferably, the substrate includes a raised portion separating the conductive elements.

-3[013] Preferably, the substrate has an aperture formed therein, each conductive element extending to at least an edge of the aperture, the aperture being configured to receive therein a pair of sensor contacts, wherein each sensor contact forms a connection with a corresponding conductive element when received within the aperture.

[014] Preferably, the conductive elements each have a castellated form.

[015] Preferably, each conductive element has a substantially circular shape whereby the conductive elements traverse around the bowl in a circular manner.

[016] Preferably, the sensor further comprises a plurality of pairs of conductive elements, each pair traversing the bowl. More preferably, the pairs of conductive elements are arranged in a substantially V shape.

[017] In a further aspect of the present disclosure, there is provided a sensor for a combustion engine fuel filter having a body defining a cavity, the body including a base, the body configured to house a filter media within the cavity, the cavity including a bowl defined between the base of the body and an end of the filter media, the sensor comprising:

a pair of conductive elements configured to traverse the bowl in use;

spacing means configured to hold the conductive elements spaced from the base and spaced from the end of the filter media.

[018] Preferably, the conductive elements are formed integral with a substrate.

[019] Preferably, the substrate includes a raised portion separating the conductive elements.

[020] Preferably, the substrate has an aperture formed therein, each conductive element extending to at least an edge of the aperture, the aperture being configured to receive therein a pair of sensor contacts, wherein each sensor contact forms a connection with a corresponding conductive element when received within the aperture.

[021] Preferably, the conductive elements each have a castellated form.

[022] Preferably, each conductive element has a substantially circular shape whereby the conductive elements traverse around the bowl in a circular manner in use.

[023] Preferably, the sensor further comprises a plurality of pairs of conductive elements.

[024] Preferably, the pairs of conductive elements are arranged in a substantially V shape.

[025] Preferably, the spacing means is configured to hold the conductive elements

-4substantially midway between the base and the end of the filter media.

[026] In yet another aspect of the present disclosure, there is provided a method for sensing the presence of water in a combustion engine fuel filter having a body defining a cavity, the body including a base, the body configured to house a filter media within the cavity, the cavity including a bowl defined between the base of the body and an end of the filter media, the method comprising:

providing a pair of conductive elements in the bowl such that the conductive elements traverse the bowl;

spacing the conductive elements between the base of the bowl and the end of the filter media means; and detecting a change in resistance between the pair of conductive elements.

[027] Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

Brief Description of the Drawings [028] FIG. 1 is an perspective view of a fuel filter with body partially removed, in accordance with embodiments of the present disclosure;

[029] [030] [031]

FIG. 2 is a cross-section view of the fuel filter shown in FIG 1;

FIG. 3 is a perspective view of a sensor for the fuel filter shown in FIG 1; and FIG. 4 is flowchart of a method in accordance with embodiments of the present disclosure.

Detailed Description [032] Referring to FIG. 1, an exemplary fuel filter 100 is depicted, in which embodiments of the present disclosure may be implemented.

[033] The fuel filter 100 comprises a body 102 having a base 104, side walls 106 and an end 108 remote from the base 104. In the embodiment, the body has a generally cylindrical configuration, however other shapes may also be used.

[034] The base 104, side walls 106 and end 108 of the body 102 define a cavity 109 within the body 102.

[035] A filter assembly 110 is housed within the cavity 109. The filter assembly 110 comprises a hollow column 112, a filter media 114 provided around the column 112, and a

-5filter end piece 116. The column 112 has a plurality of apertures 118 provided therein to allow fuel to pass through the column 112. In the exemplary fuel filter 100 shown in the figures, the filter assembly 110 is attached to the end 108. The end piece 116 of the filter assembly 110 is spaced from the base 104.

[036] A first aperture 120, provided centrally in end 108, is in fluid communication with the column 112’s interior. A second aperture 122, provided generally near the periphery of the end 108, is in fluid communication with the cavity 109. In use a connector (not shown) is threaded onto a threaded section 123 of the side wall adjacent to the end 108. The connector sealingly engages the end 108 so as to fluidly separate the apertures 120, 122 from one another. Fuel from the connector enters the fuel filter 100 via the second aperture 122 and is filtered as it passes through the filter media 114. Filtered fuel enters the hollow column 112 via the apertures 118 and exits the fuel filter 100 via the first aperture 120.

[037] A post 124 extends through an opening 126 in the base 104 and into the cavity 109. The post 124 is partially received by the filter end piece 116. The post 124 supports the filter assembly 110. The post 124 also acts as a drain for the fuel filter 100, as will be described in more detail below.

[038] The fuel filter 100 includes a bowl 128 defined between the base 104 and the filter assembly 110, in particular the filter end piece 116. Water present in fuel in the cavity

109 will collect in the bowl 128 since water is more dense than fuel. As the filter assembly

110 is spaced from the base 104, water collecting in the bowl 128 is not in contact with the filter media 114, preventing water from passing through the filter media 114 and exiting the fuel filter 100 via the first aperture 120.

[039] The post 124 of the embodiment acts as a drain for the filter 100 as follows. The post 124 has a threaded end 130 to allow the post 124 screw into the filter end piece 116. A first seal 132 is provided between the post 124 and the filter end piece 116 and a second seal 134 is provided between the post 124 and the base 104. The post 124 has a conduit 136 extending axially through it. The conduit 136 is open at an end 138 of the post 124 remote from the threaded end 130. The conduit 136 fluidly communicates with an opening 140 in the post 124 formed between the threaded end 130 and the first seal 132. [040] In normal use, the threaded end 130 of the post 124 is fully screwed into the filter end piece 116. In this position, the first seal 132 engages the filter end piece 132 and

-6prevents fluid in the cavity 109 from entering the opening 140 in the post 124.

[041] When it is desired to drain fluid from the bowl 128, for instance if water has collected in the bowl 128, the post 124 is unscrewed from the filter end piece 116 until the first seal 132 is no longer in engagement with the filter end piece 116. Fluid, for instance water, in the bowl 128 can then flow into the opening 140 in the post 124, along the conduit 136 and out of the end 138. Once draining is complete, the post 124 is screwed back into the filter end piece 116 so the first seal 132 again engages the filter end piece 116. [042] The fuel filter 100 further comprises a sensor 142 for detecting the presence of water in the bowl 128. The sensor 142 has a sensor body 144, an upper portion 146 of which is threaded. The sensor body 144 screws into a further opening in the base 104. Two sensor contacts 148, 150 extend through the sensor body 144 and project into the bowl 128. The sensor contacts 148, 150 are formed from an electrically conductive material and are connected to a sensor cable 152. The sensor cable 152 may be connected to an engine control unit (ECU) or an indicator that provides a signal to a vehicle operator. In other embodiments, wireless communications may be employed between the sensor 142 and the ECU or indicator with equal effect.

[043] The sensor 142, shown in detail in Figure 3, further comprises a pair of conductive elements 154, 156. Each conductive element 154, 156 is substantially circular in the embodiment shown in Figure 3, whereby the conductive elements traverse around the bowl 128 in a circular manner. As will be described hereafter, each conductive element 154, 156 is in electrical connection with a corresponding sensor contact 148, 150, respectively. As shown in the drawings, the conductive elements 154, 156 have a castellated form.

[044] The sensor 142 detects the presence of water in the bowl 128 by making use of the electrical conductivity difference between water, which is highly conductive, and fuel, which has low electrical conductivity. When sufficient water is in the bowl 128 that it comes into contact with the conductive elements 154, 156, the water will increase the electrical conductivity between the conductive elements 154, 156.

[045] Advantageously, since the conductive elements 154, 156 traverse the bowl 128, the sensor 142’s ability to detect water is unaffected by whether fuel filter 100 is inclined. Such inclination may occur for instance, when a vehicle fitted with the filter is travelling uphill or downhill, or passing over uneven terrain. In contrast with water-in-filter sensors

-7typical of the prior art, the sensor of this disclosure is equally sensitive to the presence of water irrespective of the direction in which the fuel filter is tilted. This ensures the water is detected and signaled to the operator or other actor by the ECU. In fuel filters typical of the prior art, water could come into contact with the filter media without its presence being indicated by the sensor when the filter was tilted in some directions.

[046] In the sensor 142 shown in the Figures, the conductive elements 154, 156 traverse the bowl adjacent to and spaced from an inner wall 158 of the bowl 128. The conductive elements 154, 156 are provided on a substrate 160 which is formed of nonconductive material suitable for immersion in fuel. The substrate 160 includes a raised portion 162 separating the conductive elements 154, 156. The substrate 160 and conductive elements 154, 156 may take any suitable form, one example of which is tracks formed on a printed circuit board. In other embodiments the conductive elements 154, 156 may be embedded in the substrate 160 so as to be formed integrally therewith.

[047] The embodiment shown in the drawings depicts the conductive elements 154, 156 being adjacent to assist with detecting water. The conductive elements 154, 156 may be spaced apart in other axes to that shown in the drawings, for instance being spaced axially rather than vertically.

[048] The substrate 160 has an aperture 161 formed therein. The conductive elements 154, 156 extend to at least an edge of the aperture 161. The aperture 161 is shaped to receive therein the sensor contacts 148, 150 so that the sensor contacts 148, 150 form a connection with a corresponding conductive element 154, 156 when received within the aperture 161. It will be appreciated that any suitable method of forming a connection may be used, such as push-fit to provide a mechanical connection, soldering, or conductive epoxy.

[049] The sensor 142 is provided with several legs 164 that hold the conductive elements 154, 156 spaced from the base 104 and spaced from the filter assembly 110. Spacing the conductive elements 154, 156 from the base 104 allows some water to collect in the bowl 128 prior to being detected by the sensor 142 when the water reaches the conductive elements 154, 156. With the presence of some water in the fuel entering the fuel filter 100, spacing the conductive elements 154, 156 from the base 104 permits a vehicle to be operated for a period of time prior to sufficient water accumulating in the bowl 128 and triggering the sensor 142. Providing the conductive elements 154, 156 close

-8to the base 104 would result in the sensor 142 detecting water in the bowl 128 when little water was present, leading to frequent sensor alerts and increasing vehicle down-time.

[050] The legs 164 also hold the conductive elements 154, 156 spaced from the filter assembly 110. If the conductive elements 154, 156 were close to, or formed on, the filter end piece 116 the sensor 142 would not detect the presence of water in the bowl 128 until the water was almost touching the filter end piece 116. A fuel filter having such an arrangement may have a bowl that was almost mostly full of water but which was not detected by the sensor 142 because of the proximity of the conductive elements 154, 156 to the filter end piece 116. If such a fuel filter was then tilted, such as by a vehicle passing over uneven terrain, water could come into contact with the filter media 114 and pass through it, possibly leading to engine damage.

[051] For the above reasons, it is preferred that the conductive elements 154, 156 are held spaced between 25-75% of the height between the base 104 and the filter end piece 116, where 0% is the base 104 and 100% is the filter end piece 116. More preferably, the conductive elements 154, 156 are held spaced by the legs 164 between 40-60% of the height between the base 104 and the filter end piece 116.

[052] It will be appreciated that other arrangements are possible beyond the embodiment described above. For instance, the conductive elements 154, 156 may be formed on the inner wall 158 spaced between the base 104 and the filter assembly 110. The conductive elements 154, 156 have been shown having a circular shape to traverse the bowl 128, however other shapes are possible including triangles, squares, octagons, hexagons, etc. In other embodiments, a plurality of pairs of conductive elements 154, 156 may be used to traverse the bowl, wherein the pairs of conductive elements 154, 156 are arranged in a substantially V-shape.

[053] Various embodiments disclosed herein are to be taken in the illustrative and explanatory sense, and should in no way be construed as limiting of the present disclosure. It is to be understood that individual features shown or described for one embodiment may be combined with individual features shown or described for another embodiment. The above described implementation does not in any way limit the scope of the present disclosure. Therefore, it is to be understood although some features are shown or described to illustrate the use of the present disclosure in the context of functional segments, such features may be omitted from the scope of the present disclosure without

-9departing from the spirit of the present disclosure as defined in the appended claims.

Industrial Applicability [054] Embodiments of the present disclosure have applicability for use and implementation in fuel filters for engines. Embodiments of the present disclosure are particularly useful for fuel filters for engines operating with diesel fuel.

[055] The fuel filter 100 of the present disclosure provides a sensor 142 for sensing the presence of water in the bowl 128 of the fuel filter 100. Conductive elements 154, 156 traverse the bowl 128 to improve the ability of the sensor 142 to sense the presence of water in the bowl 128 when the fuel filter 100 is tilted.

[056] Figure 4 shows a flowchart of a method 200 for sensing the presence of water in a fuel filter 100 in accordance with the present disclosure. The method 200 includes at step 202 providing a pair of conductive elements 154, 156 in the bowl 128 of the fuel filter 100 such that the conductive elements 154, 156 traverse the bowl 128.

[057] At step 204, the method 200 includes spacing the conductive elements 154, 156 between the base 104 and the filter assembly 110. As described above, in embodiments of the present disclosure it is preferred the conductive elements 154, 156 are spaced between 25-75% of the height between the base 104 and the filter end piece 116, where 0% is the base 104 and 100% is the filter end piece 116. More preferably, the conductive elements 154, 156 are held spaced by the legs 164 between 40-60% of the height between the base 104 and the filter end piece 116.

[058] At step 206, the method 200 includes detecting a change in resistance between the pair of conductive elements 154, 156.

[059] All numerical terms, such as, but not limited to, “first”, “second”, “third”, or any other ordinary and/or numerical terms, should also be taken only as identifiers, to assist the reader’s understanding of the various embodiments, variations, components, and/or modifications of the present disclosure, and are not intended to create any limitations, particularly as to the order, or preference, of any embodiment, variation, component and/or modification relative to, or over, another embodiment, variation, component and/or modification.

-10LIST OF ELEMENTS

100	fuel filter
102	body
104	base
106	side walls
108	end
109	cavity
110	filter assembly
112	column
114	filter media
116	filter end piece
118	apertures
120	first aperture
122	second aperture
123	threaded section
124	post
126	opening
128	bowl
130	threaded end
132	first seal
134	second seal
136	conduit
138	end
140	opening
142	sensor
144	sensor body
146	upper portion
148, 150	sensor contacts
152	sensor cable
154, 156	conductive elements
158	inner wall

160	substrate
161	aperture
162	raised portion
164	legs
200	method
202	step
204	step
206	step

Claims

1. A fuel filter for a combustion engine, comprising:

a body defining a cavity, the body including a base, the body configured to house a filter assembly within the cavity;

the cavity including a bowl defined between the base of the body and an end of the filter assembly;

a sensor comprising a pair of conductive elements traversing the bowl, the conductive elements held spaced from the base and spaced from the filter assembly.

2. The fuel filter of claim 1, wherein the conductive elements traverse the bowl adjacent an inner wall of the bowl.

3. The fuel filter of claim 1, wherein the conductive elements are formed on an inner wall of the bowl.

4. The fuel filter of any of claims 1 to 3, wherein the conductive elements are formed integrally with a substrate.

5. The fuel filter of claim 4, wherein the substrate includes a raised portion separating the conductive elements.

6. The fuel filter of claim 4 or 5, wherein the substrate has an aperture formed therein, each conductive element extending to at least an edge of the aperture, the aperture being configured to receive therein a pair of sensor contacts, wherein each sensor contact forms a connection with a corresponding conductive element when received within the aperture.

7. The fuel filter of any of claims 1 to 6, wherein the conductive elements each have a castellated form.

8. The fuel filter of any of claims 1 to 7, wherein each conductive element has a substantially circular shape whereby the conductive elements traverse around the bowl in a circular manner.

-139. The fuel filter of any of claims 1 to 7, further comprising a plurality of pairs of conductive elements, each pair traversing the bowl.

10. The fuel filter of claim 9, wherein the pairs of conductive elements are arranged in a substantially V shape.

11. A sensor for a combustion engine fuel filter having a body defining a cavity, the body including a base, the body configured to house a filter assembly within the cavity, the cavity including a bowl defined between the base of the body and the filter assembly, the sensor comprising:

a pair of conductive elements configured to traverse the bowl in use;

spacing means configured to hold the conductive elements spaced from the base and spaced from the filter assembly.

12. The sensor of any of claim 11, wherein the conductive elements are formed integral with a substrate.

13. The sensor of claim 12, wherein the substrate includes a raised portion separating the conductive elements.

14. The sensor of claim 12 or 13, wherein the substrate has an aperture formed therein, each conductive element extending to at least an edge of the aperture, the aperture being configured to receive therein a pair of sensor contacts, wherein each sensor contact forms a connection with a corresponding conductive element when received within the aperture.

15. The sensor of any of claims 11 to 14, wherein the conductive elements each have a castellated form.

16. The sensor of any of claims 11 to 15, wherein each conductive element has a substantially circular shape whereby the conductive elements traverse around the bowl in a circular manner in use.

-1417. The sensor of any of claims 11 to 16, further comprising a plurality of pairs of conductive elements.

18. The sensor of claim 17, wherein the pairs of conductive elements are arranged in a substantially V shape.

19. The sensor of any of claims 11 to 18, wherein the spacing means is configured to hold the conductive elements substantially midway between the base and the end of the filter media.

20. A method for sensing the presence of water in a combustion engine fuel filter having a body defining a cavity, the body including a base, the body configured to house a filter assembly within the cavity, the cavity including a bowl defined between the base of the body and the filter assembly, the method comprising:

spacing the conductive elements between the base of the bowl and the filter assembly; and detecting a change in resistance between the pair of conductive elements.

21. A fuel filter substantially as herein described with reference to the accompanying drawings.

22. A sensor for a fuel filter substantially as herein described with reference to the accompanying drawings.

23. A method for sensing the presence of water in a fuel filter substantially as herein described with reference to the accompanying drawings.

Intellectual

Property

Office

Application No: GB1618242.0