JP2015014214A - Fuel filter apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel filter apparatus capable of filtering out water of a small particle diameter from fuel while suppressing clogging of a filter element for filtering out the water.SOLUTION: An aggregation filter element 14 is configured by alternately superimposing water repellent filter mediums 141 and hydrophilic filter mediums 142. The aggregation filter element 14 is arranged within a case so that fuel can flow along boundary surfaces 14c between the water repellent filter mediums 141 and the hydrophilic filter mediums 142. Therefore, water particles are aggregated to have a larger particle diameter more downstream in a fuel flow direction in the aggregation filter element 14. Owing to this, it is unnecessary to provide smaller passing holes of the aggregation filter element 14. Even if fuel containing water particles of a small particle diameter flows into the aggregation filter element 14, the water can be easily precipitated in a storage space. Therefore, it is easy to filter out the water of the small particle diameter from the fuel while suppressing clogging of the aggregation filter element 14.

Description

  The present invention relates to a fuel filtration device for separating and removing moisture in fuel.

  2. Description of the Related Art Conventionally, a fuel filtration device for separating and removing moisture in fuel is known. For example, this is the fuel filtering device disclosed in Patent Document 1. The fuel filtration device of Patent Document 1 includes a first chamber that communicates with a fuel inlet, a second chamber that is provided downstream of the first chamber, and a first chamber and a second chamber. And a net provided between the two chambers. The net is coated with a material such as polytetrafluoroethylene (PTFE) or silicon, and through holes having a diameter of about 200 microns or less are formed in order to capture moisture present in the fuel.

Japanese Patent Laid-Open No. 10-89186

  By the way, the particle diameter of the water mixed in the fuel flowing through the fuel filtering device is smaller when the fuel is pumped to the fuel filtering device than when the fuel is sucked from the fuel filtering device. Easy to be. In order to sufficiently separate and remove such water having a small particle diameter, for example, in the fuel filtration device of Patent Document 1, it is conceivable to reduce the diameter of the passage hole formed in the net.

  However, if the diameter of the through-hole formed in the net is reduced, the net, which is a filter element for separating and removing water, is likely to be clogged with solid foreign matters.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a fuel filtration device that can easily separate and remove water having a small particle diameter from fuel while suppressing clogging of a filter element for separating and removing water. .

In order to achieve the above object, the fuel filtration device according to the first aspect of the present invention includes a hydrophilic filter medium (142, 146b) having hydrophilicity and a water-repellent filter medium (141, 146a) having water repellency. An agglomerated filter element (14) configured to alternately superimpose the hydrophilic filter medium and the water-repellent filter medium, and agglomerates moisture in the fuel;
A case (12) in which a coagulation filter element is accommodated and a storage space (12a) in which water in the fuel that has settled from the coagulation filter element is stored is formed,
The agglomeration filter element is arranged in the case so that the fuel flows along the boundary surface (14c) constituting the boundary between the hydrophilic filter medium and the water-repellent filter medium.

  According to the above-described invention, the aggregation filter element is configured by alternately superposing the hydrophilic filter medium and the water-repellent filter medium. In the aggregation filter element, the boundary between the hydrophilic filter medium and the water-repellent filter medium is formed. Since the fuel flows along the boundary surface, the water particles mixed in the fuel flowing along the boundary surface easily flow from the water-repellent filter medium to the hydrophilic filter medium, but on the contrary, it is difficult to flow. The water particles are aggregated in the hydrophilic filter medium toward the downstream side, and the particle diameter is increased. Therefore, even if fuel containing water particles having a small particle diameter flows into the agglomeration filter element, the water easily settles in the storage space, so that water having a small particle diameter is separated and removed from the fuel while suppressing clogging of the aggregation filter element. Is easy.

  In addition, each code | symbol in the parenthesis described in this column and the claim respond | corresponds to each code | symbol described in embodiment mentioned later.

It is sectional drawing of the fuel filtration apparatus 10 which concerns on 1st Embodiment. It is the perspective view which represented the aggregation filter element 14 in the 1st Embodiment with the single-piece | unit. FIG. 3 is a cross-sectional view of the aggregation filter element 14 of FIG. 2 cut along a cross section including its axis. It is the perspective view which represented the aggregation filter element 14 of 2nd Embodiment alone, and is a figure equivalent to FIG. In the second embodiment, the agglomerated filter element 14 formed by winding a sheet-like material composed of a water-repellent filter medium 141 and a hydrophilic filter medium 142 into a cylindrical shape is developed in the sheet-like material. It is the perspective view which represented the partition filter medium 144 of FIG. It is a figure for demonstrating the roller shaping | molding which shape | molds the partition filter medium 144 of FIG. 6 in a corrugated sheet shape. It is sectional drawing which cut | disconnected the aggregation filter element 14 of 2nd Embodiment in the cross section containing the axial center. It is sectional drawing which cut | disconnected the aggregation filter element 14 of 3rd Embodiment in the cross section containing the axial center, Comprising: It is a figure corresponded in FIG. FIG. 10 is a perspective view showing a roll-shaped aggregation filter element 14 as a single unit in the fourth embodiment, and is a diagram showing a state in which a part of the aggregation filter element 14 is developed. It is sectional drawing of the fuel filtration apparatus 10 which concerns on 5th Embodiment, Comprising: It is a figure equivalent to FIG. It is sectional drawing of the fuel filtration apparatus 10 similar to FIG. 11, Comprising: It is the figure showing the effect | action of the aggregation filter element 14 and the dust filter element 16 in 5th Embodiment. It is a figure which shows the modification of the aggregation filter element 14 of 4th Embodiment, Comprising: It is a perspective view of the aggregation filter element 14 equivalent to FIG. It is sectional drawing which shows the radial direction cross section of the aggregation filter element 14 in the A section of FIG. It is a figure which shows the modification of the fuel filtration apparatus 10 of 5th Embodiment, Comprising: It is sectional drawing equivalent to FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
A first embodiment of the present invention will be described. FIG. 1 is a cross-sectional view of a fuel filtration device 10 according to the first embodiment. 1 is used in a fuel supply system for an internal combustion engine (not shown) such as a diesel engine or a gasoline engine. The fuel filtering device 10 separates and removes moisture, dust and the like mixed in the fuel supplied to the internal combustion engine from the fuel. In FIG. 1, the lower side of the figure is the lower side of the gravity direction DRg, and the thick line arrow represents the fuel flow. This also applies to FIGS. 11, 12, and 15 described later unless otherwise specified.

  As shown in FIG. 1, the fuel filtering device 10 includes a case 12 that is a housing of the fuel filtering device 10, an aggregation filter element 14 that aggregates water mixed in the fuel, and dust that is mixed in the fuel. And a dust filter element 16.

  The case 12 accommodates the aggregation filter element 14 and the dust filter element 16. A storage space 12 a is formed in the lower part of the case 12, and the aggregation filter element 14 and the dust filter element 16 are disposed in the case 12 above the storage space 12 a in the gravity direction DRg. Therefore, the water in the fuel that has settled from the aggregation filter element 14 and the dust in the fuel that has settled from the dust filter element 16 are stored in the storage space 12a.

  Further, the case 12 includes a first opening 121 that is a fuel inlet through which fuel flows and a plurality of second openings 122 that are fuel outlets through which fuel flows out. The first opening 121 is connected to the fuel tank 18 via a fuel pipe. A fuel pump 20 is interposed between the fuel tank 18 and the first opening 121, and the fuel pump 20 pumps fuel from the fuel tank 18 to the first opening 121. The second opening 122 is connected to a fuel injection device 22 that injects fuel into the combustion chamber of the internal combustion engine via a fuel pipe.

  A cock, that is, an opening / closing valve (not shown) is provided at the bottom of the case 12, that is, the bottom of the storage space 12a. The water and dust collected at the bottom of the storage space 12a are discharged to the outside of the case 12 when the cock is opened.

  The case 12 also includes a fuel passage 123 that guides the fuel that has flowed from the first opening 121 to the aggregation filter element 14.

  FIG. 2 is a perspective view showing the aggregation filter element 14 as a single unit. As shown in FIG. 2, the aggregation filter element 14 includes a sheet-like water-repellent filter medium 141 having water repellency and a sheet-like hydrophilic filter medium 142 having hydrophilicity. The water repellent filter medium 141 and the hydrophilic filter medium 142 are stacked in the thickness direction, and the aggregation filter element 14 is formed in a cylindrical shape by winding the stacked water repellent filter medium 141 and the hydrophilic filter medium 142. Has been. Therefore, in the aggregation filter element 14, the water repellent filter medium 141 and the hydrophilic filter medium 142 are alternately overlapped in the radial direction. For example, both the water repellent filter medium 141 and the hydrophilic filter medium 142 are made of filter paper.

  Further, as shown in FIG. 1, the fuel flowing out from the fuel passage 123 is supplied to the upper end surface 14 a of the aggregation filter element 14. And the lower end surface 14b of the aggregation filter element 14 is open | released toward the storage space 12a, and the fuel which flows out from the lower end surface 14b flows into the storage space 12a. Next, the fuel flows out from the second opening 122 toward the fuel injection device 22 through the dust filter element 16.

  Next, the effect | action which the aggregation filter element 14 aggregates water is demonstrated using FIG. FIG. 3 is a cross-sectional view of the aggregation filter element 14 cut along a cross section including its axis. In FIG. 3, the arrows shown superimposed on the water-repellent filter medium 141 and the hydrophilic filter medium 142 indicate the movement of water particles contained in the fuel. In FIG. 3, the water particles contained in the fuel are represented by a circular figure Pw.

  As shown in FIG. 3, the fuel flows in from the upper end surface 14a of the aggregation filter element 14 and flows downward in the gravity direction DRg. That is, in the aggregation filter element 14, the fuel flows along the boundary surface 14 c constituting the boundary between the water repellent filter medium 141 and the hydrophilic filter medium 142.

  In the agglomerated filter element 14, water particles that are small with respect to both the fine passage holes formed in the water-repellent filter medium 141 and the fine passage holes formed in the hydrophilic filter medium 142 are water-repellent filter medium 141. Both of the filter medium 142 and the hydrophilic filter medium 142 can pass therethrough. However, in the process in which the fuel flows through the aggregation filter element 14, the water particles in the fuel easily flow from the water repellent filter medium 141 to the hydrophilic filter medium 142, but hardly flow from the hydrophilic filter medium 142 to the water repellent filter medium 141. .

  Therefore, as shown in FIG. 3, as the fuel approaches the lower end surface 14b from the upper end surface 14a of the agglomeration filter element 14, the water particles in the fuel collect in the hydrophilic filter medium 142. The closer to the end face 14b, the larger. As a result, in the fuel that has flowed into the storage space 12 a from the lower end surface 14 b of the aggregation filter element 14, the enlarged water particles settle in the storage space 12 a and do not flow into the dust filter element 16.

  As described above, according to the present embodiment, the aggregation filter element 14 is configured by alternately superposing the water-repellent filter medium 141 and the hydrophilic filter medium 142. The aggregation filter element 14 is arranged in the case 12 so that the fuel flows along the boundary surface 14c that constitutes the boundary between the water-repellent filter medium 141 and the hydrophilic filter medium 142. Therefore, as shown in FIG. 3, water particles are aggregated in the hydrophilic filter medium 142 toward the downstream side of the fuel flow, and the particle diameter increases. Therefore, it is not necessary to make the passage hole of the aggregation filter element 14 fine in order to capture fine water particles. Even if fuel containing water particles having a small particle diameter flows into the agglomeration filter element 14, the water easily settles in the storage space 12 a, so that water having a small particle diameter is reduced from the fuel while suppressing clogging of the aggregation filter element 14. It is easy to separate and remove.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the present embodiment, differences from the first embodiment will be mainly described. Further, the same or equivalent parts as those of the above-described embodiment will be described by omitting or simplifying them. The same applies to third and later embodiments described later.

  In the present embodiment, unlike the first embodiment described above, the cross-sectional area of the hydrophilic filter medium 142 orthogonal to the fuel flow direction in the aggregation filter element 14 is smaller toward the downstream side of the fuel flow. Thereby, in this embodiment, the effect of aggregating water particles in the fuel can be obtained more than in the first embodiment.

  A specific configuration of the aggregation filter element 14 will be described. FIG. 4 is a perspective view showing the aggregation filter element 14 of the present embodiment as a single unit, and corresponds to FIG. 2 described above. FIG. 5 is a diagram in which agglomerated filter element 14 formed by winding a sheet-like material composed of a water-repellent filter material 141 and a hydrophilic filter material 142 into a cylindrical shape is developed on the sheet-like material.

  As shown in FIGS. 4 and 5, the aggregation filter element 14 is formed by winding an element base material 143 that is a sheet-like material into a cylindrical shape. In addition to the water-repellent filter medium 141 and the hydrophilic filter medium 142, the element substrate 143 includes a partition filter medium 144 formed into a corrugated plate shape as shown in FIG. FIG. 6 is a perspective view showing the partition filter medium 144 as a single unit.

  The partition filter medium 144 is formed of a thin member such as paper that allows both fuel and water to pass therethrough. As shown in FIG. 5, the partition filter medium 144 is a member that becomes a boundary between the water-repellent filter medium 141 and the hydrophilic filter medium 142. A trough is formed on one side and the other side of the partition filter medium 144, and the water repellent filter medium 141 is filled in the trough on the one side to fill the trough, and the trough on the other side. The portion is filled with a hydrophilic filter medium 142 so as to fill the valley. In the present embodiment, for example, one side or the other side of the partition filter medium 144 corresponds to the boundary surface 14 c between the water repellent filter medium 141 and the hydrophilic filter medium 142.

  As shown in FIG. 5, due to the corrugated plate shape of the partition filter medium 144, the water-repellent filter medium 141 is formed such that the cross-sectional area perpendicular to the fuel flow direction increases toward the downstream side of the fuel flow. The hydrophilic filter medium 142 is formed so that the cross-sectional area perpendicular to the fuel flow direction becomes smaller toward the downstream side of the fuel flow.

  The partition filter medium 144 is formed by roller molding as shown in FIG. 7, for example. FIG. 7 is a view for explaining roller molding for molding the partition filter medium 144 into a corrugated plate shape. As shown in FIG. 7, a belt-shaped filter paper 27 that is a raw material of the partition filter medium 144 is fed in the arrow ARsm direction, and has a first gear 28 that has outer peripheral teeth 281 and rotates in the arrow AR1r direction, and an outer periphery that meshes with the outer peripheral teeth 281. The partition filter medium 144 is formed by sandwiching the filter paper 27 between the teeth 301 and the second gear 30 that rotates in the direction of the arrow AR2r. The circumferential width of the outer peripheral teeth 281 of the first gear 28 increases from one axial direction to the other, and the circumferential width of the outer peripheral teeth 301 of the second gear 30 increases from one axial direction. It narrows toward the other side.

  Next, the effect | action which the aggregation filter element 14 aggregates water is demonstrated using FIG. FIG. 8 is a cross-sectional view of the aggregation filter element 14 cut along a cross section including its axis. In FIG. 8, the partition filter medium 144 is omitted for the sake of simplicity. The same applies to FIG. 9 described later.

  The water particles in the fuel gather on the hydrophilic filter medium 142 as in the first embodiment. In this embodiment, as shown in FIG. 8, since the cross-sectional area of the hydrophilic filter medium 142 orthogonal to the fuel flow direction is smaller toward the downstream side of the fuel flow, the water particles are bound to each other toward the downstream side of the fuel flow. It tends to be a larger particle size. Therefore, in this embodiment, the collection effect which collects water becomes larger than 1st Embodiment.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In the present embodiment, differences from the second embodiment will be mainly described.

  FIG. 9 is a cross-sectional view of the agglomerated filter element 14 cut along a cross section including its axis, and corresponds to FIG. 8 described above. In FIG. 9, the water particles contained in the fuel are represented by a circular figure Pw as in FIG.

  In the aggregation filter element 14 of the present embodiment, as shown in FIG. 9, the cross-sectional area of the water-repellent filter medium 141 orthogonal to the fuel flow direction becomes larger toward the downstream side of the fuel flow as in the second embodiment. ing. However, unlike the second embodiment, the density of the water repellent filter medium 141 is rougher toward the downstream side of the fuel flow. In other words, the passage hole diameter of the water repellent filter medium 141 gradually increases from the upstream side to the downstream side in the fuel flow direction, and the passage hole diameter is the smallest at the upper end surface 14a and the largest at the lower end surface 14b. It has become.

  Although the water particles are small on the upper end surface 14a that is the inflow portion of the fuel, the water repellent filter medium 141 has a small passage hole diameter, so that the water particles hardly flow into the water repellent filter medium 141. In addition, although the passage hole diameter of the water repellent filter medium 141 is large on the downstream side of the fuel flow, the water particles in the hydrophilic filter medium 142 are also large, so that it hardly flows into the water repellent filter medium 141. Absent. On the other hand, since the fuel also flows to the water-repellent filter medium 141, the flow resistance of the fuel can be suppressed by increasing the passage hole diameter of the water-repellent filter medium 141. In short, the portion of the water-repellent filter medium 141 having a small passage hole diameter is limited to the upstream portion of the fuel flow, and the cross-sectional area of the water-repellent filter media 141 is originally small at the upstream portion of the fuel flow. The pressure loss due to can be reduced.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. In the present embodiment, differences from the second embodiment will be mainly described.

  FIG. 10 is a perspective view showing a roll-shaped aggregation filter element 14 as a single unit, and is a view showing a state where a part of the aggregation filter element 14 is developed.

  In the second embodiment described above, the water-repellent filter medium 141 and the hydrophilic filter medium 142 are respectively formed in accordance with the shape of the partition filter medium 144. However, in this embodiment, the agglomerated filter element 14 includes the partially coated filter medium 146. And the partial coating filter medium 146 is wound around. The partial coating filter medium 146 is formed by partially applying a water-repellent water-repellent coating to a hydrophilic sheet-like base material.

  As shown in FIG. 10, the agglomeration filter element 14 is composed of a partially coated filter medium 146 wound in a cylindrical shape. That is, the aggregation filter element 14 is configured by overlapping the partially coated filter media 146 in the radial direction. The partially coated filter medium 146 is partially water-repellent coated so that the shape of the partially coated filter medium 146 seen in the thickness direction forms a trapezoidal shape. Therefore, in the partial coating filter medium 146, the water-repellent part 146a that has been subjected to the water-repellent coating and the hydrophilic part 146b that has not been subjected to the water-repellent coating and remain hydrophilic are alternately arranged in the longitudinal direction of the partial coating filter medium 146. Adjacent to each other. The water-repellent coating penetrates not only on the surface of the partially coated filter medium 146 but also in the thickness direction.

  A plurality of water repellent portions 146a and hydrophilic portions 146b are formed while the partial coating filter medium 146 is wound once. That is, the water repellent part 146 a and the hydrophilic part 146 b are arranged at a pitch sufficiently short with respect to the outer peripheral length of the aggregation filter element 14.

  The water repellent part 146a has a trapezoidal shape having an upper base on the upstream side of the fuel flow and a lower bottom wider than the upper base on the downstream side when viewed from the thickness direction of the partial coating filter medium 146. Further, the hydrophilic portion 146b has a trapezoidal shape having an upper base on the upstream side of the fuel flow and a lower base narrower than the upper base on the downstream side. Therefore, the cross-sectional area perpendicular to the fuel flow direction is larger toward the downstream side of the fuel flow in the water repellent portion 146a, but is smaller toward the downstream side of the fuel flow in the hydrophilic portion 146b. From such a configuration of the agglomeration filter element 14, for example, the collection effect of collecting water in the fuel can be obtained in the same manner as the aggregation filter element 14 of the second embodiment shown in FIG. 8.

  Further, according to the present embodiment, the water-repellent part 146a corresponding to the water-repellent filter medium 141 in FIG. 8 and the hydrophilic part 146b corresponding to the hydrophilic filter medium 142 in FIG. Since it is formed, the number of parts constituting the aggregation filter element 14 can be reduced as compared with the aggregation filter element 14 of the second embodiment. And it becomes easy to aim at cost reduction by reduction of a number of parts.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described. In the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 11 is a cross-sectional view of the fuel filtration device 10 according to the fifth embodiment, and corresponds to FIG. 1 described above.

  The aggregation filter element 14 of the present embodiment has the same internal configuration as the aggregation filter element 14 of the third embodiment. That is, as shown in FIG. 9, the density of the water-repellent filter medium 141 included in the aggregation filter element 14 becomes rougher toward the downstream side of the fuel flow.

  As shown in FIG. 11, in the fuel filtering device 10, the fuel that has flowed from the first opening 121 sequentially passes through the dust filter element 16 and the aggregation filter element 14 and flows out from the second opening 122. . That is, the dust filter element 16 is disposed on the upstream side of the fuel flow with respect to the aggregation filter element 14.

  FIG. 12 is a cross-sectional view of the fuel filtration device 10 similar to that in FIG. 11, and shows the operation of the aggregation filter element 14 and the dust filter element 16. As shown in FIG. 12, the fuel containing dust and moisture flows into the dust filter element 16 from below the dust filter element 16 in the gravitational direction DRg, and the dust in the fuel is collected by the dust filter element 16. . The water particles in the fuel that have passed through the dust filter element 16 become larger as the fuel flows downstream in the aggregation filter element 14, and the storage space below the case 12 from the lower end surface 14 b of the aggregation filter element 14. Sediment to 12a. In FIG. 12, water particles contained in the fuel are represented by a circular figure Pw, and dust is represented by an irregular figure Pd.

  According to the present embodiment, the dust filter element 16 is disposed on the upstream side of the fuel flow with respect to the agglomeration filter element 14. Therefore, even if the passage hole diameter of the agglomeration filter element 14 is reduced in the vicinity of the upper end surface 14a, agglomeration is performed. It is possible to prevent the filter element 14 from being clogged with dust.

(Other embodiments)
(1) In the second embodiment described above, one side of the partition filter medium 144 is filled with a water-repellent filter medium 141. The partition filter medium 144 is made water-repellent by being coated with a water-repellent material such as silicon. You may have.

  (2) In the above-described fourth embodiment, the water-repellent part 146a and the hydrophilic part 146b are arranged at a sufficiently short pitch with respect to the outer peripheral length of the aggregation filter element 14, but for example, the same as the outer peripheral length. It may be arranged at a pitch of about a degree, and as shown in FIG. 13 which is a perspective view of the aggregation filter element 14 corresponding to FIG. 10, it is arranged at a sufficiently long pitch with respect to the outer peripheral length of the aggregation filter element 14. May be. Or the water repellent part 146a and the hydrophilic part 146b may be arrange | positioned combining not a fixed pitch but a short pitch and a long pitch.

  In the agglomeration filter element 14 shown in FIG. 13, as shown in FIG. 14 which is a cross-sectional view cut along the radial direction in the portion A of FIG. 13, the water repellent portion 146a increases from the upstream to the downstream of the fuel flow. The radial width WDa of the hydrophilic portion 146b becomes wider and the radial width WDb of the hydrophilic portion 146b becomes narrower.

  In addition, not only the partially coated filter medium 146 is wound to form the agglomerated filter element 14, but the agglomerated filter element 14 is wound with a sheet-like water-repellent filter medium having water repellency superimposed on the partially coated filter medium 146. Or a sheet-like hydrophilic filter medium having hydrophilicity may be formed by being superimposed on the partially coated filter medium 146 and wound.

  (3) In FIG. 11 of the fifth embodiment described above, no filter element is disposed on the downstream side of the fuel flow with respect to the aggregation filter element 14, but as shown in FIG. In addition to the dust filter element 16, a second dust filter element 34 for collecting dust mixed in the fuel may be provided.

  In FIG. 15, the second dust filter element 34 is disposed in the fuel passage 123. That is, it is disposed downstream of the fuel flow with respect to the aggregation filter element 14. And the coarseness of the eyes of the dust filter element 16 is from the fifth embodiment so that the dust collected by the dust filter element 16 is about the same size as the water particles flowing into the dust filter element 16. Is also rough. On the other hand, the coarseness of the second dust filter element 34 is denser than that of the dust filter element 16. Therefore, the dust filter element 16 is less likely to be clogged, so that the life of the fuel filtration device 10 can be extended.

  In addition, this invention is not limited to above-described embodiment, In the range described in the claim, it can change suitably. In each of the above-described embodiments, it is needless to say that elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Yes. Further, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly limited to a specific number when clearly indicated as essential and in principle. The number is not limited to the specific number except for the case. In each of the above embodiments, when referring to the material, shape, positional relationship, etc. of the constituent elements, etc., unless otherwise specified, or in principle limited to a specific material, shape, positional relationship, etc. The material, shape, positional relationship, etc. are not limited.

  Further, the above embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible. For example, in the fuel filtration device 10 of FIGS. 11 and 15, the aggregation filter element 14 of FIG. 2, 4, 10, or 13 may be used.

DESCRIPTION OF SYMBOLS 10 Fuel filtration apparatus 12 Case 12a Storage space 14 Aggregation filter element 14c Interface 141 Water-repellent filter medium 142 Hydrophilic filter medium 146a Water-repellent part 146b Hydrophilic part

Claims (5)

It has a hydrophilic filter medium (142, 146b) having hydrophilicity and a water-repellent filter medium (141, 146a) having water repellency, and the hydrophilic filter medium and the water-repellent filter medium are alternately stacked. A coalescing filter element (14) that agglomerates moisture in the fuel;
A case (12) in which a storage space (12a) in which the water in the fuel that has settled from the aggregation filter element and that stores the aggregation filter element is stored is formed;
The agglomerated filter element is disposed in the case so that the fuel flows along a boundary surface (14c) constituting a boundary between the hydrophilic filter medium and the water repellent filter medium. Filtration device.   2. The fuel filtration device according to claim 1, wherein a cross-sectional area of the hydrophilic filter medium orthogonal to the fuel flow direction in the aggregation filter element is smaller toward a downstream side of the fuel flow. The agglomerated filter element is configured by overlapping a partially coated filter medium (146) formed by partially applying a water-repellent water-repellent coating to a hydrophilic sheet-like base material,
The partial coating filter medium includes the water repellent part (146a) coated with the water repellent coating as the water repellent filter medium, and the hydrophilic part (146b) not coated with the water repellent coating as the hydrophilic filter medium. And
3. The fuel filtering device according to claim 1, wherein a cross-sectional area of the water-repellent portion perpendicular to the fuel flow direction in the partial coating filter medium increases toward a downstream side of the fuel flow. 4. A first dust filter element (16) disposed upstream of the agglomeration filter element and capturing dust in the fuel;
4. The fuel filter device according to claim 1, wherein the water-repellent filter medium has a coarseness toward a downstream side of the fuel flow in the aggregation filter element. 5. A second dust filter element (34) disposed downstream of the agglomeration filter element and capturing dust in the fuel;
5. The fuel filtering device according to claim 4, wherein the second dust filter element is denser and denser than the first dust filter element.