Fuel filter

Abstract

The present invention provides a structure in which a filter material can be easily replaced, and can improve oil and water separation performance. A fuel filter is provided with: a housing having a substantially cylindrical filter housing having an opening at one end and a cover at the other end, and a head provided to the filter housing so as to cover the opening; and a filter element which is provided in the internal space of the housing and which can be attached to and detached from the housing. A filter element is provided with: a first filter having a cylindrical first filter section formed by folding a sheet-like filter material in a pleated shape; the second filter is arranged on the inner side of the first filtering part; and a first plate provided with a first filter and a second filter, the second filter having: a second filter part formed in a cylindrical shape by connecting both ends of a mesh-shaped thin plate; the first end part covers the first end of the second filtering part; the first plate is arranged on the head, a first through hole is formed in the center of the first plate, the first end part is arranged on the first plate, a second through hole communicating the hollow part of the second filtering part with the first through hole is formed in the first end part, and the first plate and the first end part can be assembled and disassembled.

Description

Technical Field

[0001] The present invention relates to a fuel filter. Background Art

[0002] Patent document 1 discloses a fuel filter having a first filter material whose central axis is arranged substantially along a vertical direction and a second filter material arranged inside a first inner cylinder. In the first inner cylinder of the fuel filter, a through hole is formed in a first region which is a band-shaped region near the upper end, and no through hole is formed in a second region outside the first region.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-203091 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the invention described in Patent Document 1, cylindrical pleated filter materials formed by folding plate-like materials are used in the first filter material and the second filter material, so the filter element becomes expensive. Since the filter element is a consumable, it is expected to be cheap and easy to replace, but it is not enough to just be easy to replace. Since it is a fuel filter, the separation performance of oil and water must be kept high.

[0008] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fuel filter which has a structure that facilitates replacement of a filter medium and can improve the separation performance of oil and water.

[0009] Solutions to Solve Problems

[0010] The fuel filter of the present invention comprises, for example, a housing having a filter case of a substantially cylindrical shape having an opening at one end and covered at the other end, and a head provided on the filter case so as to cover the opening; and a filter element provided in an internal space of the housing and detachable from the housing, wherein the fuel filter is characterized in that the filter element comprises: a first filter having a cylindrical first filter portion formed by folding a sheet-like filter material in a pleated shape; a second filter provided inside the first filter portion; and a first plate provided with the first filter and the second filter, the second filter comprising: a second filter portion formed in a cylindrical shape by connecting both ends of a mesh-like thin plate; a first end portion covering a first end of the second filter portion; and a second end portion covering a second end of the second filter portion on a side opposite to the first end, the first plate being provided on the head and having a first through hole formed in the center, the first end portion being provided on the first plate and having a second through hole connecting a hollow portion of the second filter portion with the first through hole, and the first plate and the first end portion being detachable.

[0011] According to the fuel filter of the present invention, the filter element has a first plate arranged on the head, and a first filter and a second filter arranged on the first plate, and the second filter is arranged on the inner side of the first filter portion. The first filter has a first cylindrical filter portion formed by folding a sheet-like filter material into a pleated shape, and the second filter has a second cylindrical filter portion formed by connecting the two ends of a mesh-like thin plate. The first end of the second filter is detachably arranged on the first plate. As a result, the fuel passes through the first filter portion, and the water contained in the fuel becomes large-diameter water droplets, and the water droplets fall downward, and the surface of the second filter portion is used to capture the water droplets that have not fallen, thereby improving the separation performance of oil and water. In addition, the second filter that is not prone to pore blockage is easy to remove, and the first filter portion that is prone to pore blockage can be easily replaced.

[0012] Alternatively, the first through hole may include a large diameter portion for inserting the first end portion and a small diameter portion having a smaller diameter than the large diameter portion, the small diameter portion being sandwiched between the head and the large diameter portion, and a gripping portion being provided at the second end portion. Thus, a user can grip and extract the second filter from the first plate using the gripping portion, and the second filter can be easily removed.

[0013] Alternatively, the fuel filter may include a cylindrical baffle plate disposed between the first filter and the second filter, one end of the baffle plate being disposed on the first plate. Thus, the movement of the fuel increases under the action of the baffle plate, and water droplets fall more easily, thereby improving the separation performance of oil and water.

[0014] A fuel filter according to another embodiment of the present invention comprises, for example: a housing having a filter shell of a substantially cylindrical shape having an opening at one end and being covered at the other end, and a head arranged on the filter shell in a manner covering the opening; and a filter element arranged in an internal space of the housing and capable of being loaded and unloaded relative to the housing, wherein the fuel filter is characterized in that the filter element comprises: a first filter having a cylindrical first filter portion formed by folding a sheet-like filter material into a pleated shape; a cylindrical baffle plate arranged on the inner side of the first filter; and a first plate provided with the first filter and the baffle plate, the first plate being arranged on the head and having a first through hole formed in the center, the first through hole connecting a hollow portion of the baffle plate with an outflow portion arranged on the head.

[0015] According to the fuel filter of the present invention, the filter element comprises a first plate provided on the head, a first filter provided on the first plate, and a baffle plate provided on the inner side of the first filter portion. Thus, under the action of the baffle plate, the amount of fuel movement increases and water droplets fall easily, which can improve the separation performance of oil and water.

[0016] The baffle plate may have a tapered shape whose diameter gradually decreases as it moves away from the first plate. This facilitates the fuel to flow downward along the baffle plate.

[0017] The height of the baffle plate may be greater than the height of the first filter unit. This increases the amount of fuel movement and makes it easier for water droplets to fall.

[0018] The baffle plate may be provided with spiral grooves or ribs on its outer peripheral surface. This further increases the amount of fuel movement and makes it easier for water drops to fall.

[0019] Effects of the Invention

[0020] According to the present invention, the filter medium can be easily replaced and the separation performance of oil and water can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional view schematically showing a fuel filter 1 as one embodiment of the present invention.

[0022] Figure 2 It is a cross-sectional view schematically showing the filter element 40 .

[0023] Figure 3 1 is an exploded view showing an outline of the filter element 40 .

[0024] Figure 4 It is a cross-sectional view schematically showing the filter element 40A.

[0025] Figure 5 It is an exploded view showing the outline of the filter element 40A.

[0026] Figure 6 It is a cross-sectional view schematically showing the fuel filter 2 .

[0027] Figure 7 It is a cross-sectional view schematically showing the filter element 40B.

[0028] Figure 8 is a diagram showing an overview of the baffle plate 45, Figure 8 (A) is the side view, Figure 8 (B) is a cross-sectional view.

[0029] Fig. 9 4 is a diagram showing an overview of the blocking plate 45A. Fig. 9 (A) is the side view, Fig. 9 (B) is a cross-sectional view.

[0030] Fig.10 It is a diagram showing the outline of the baffle plate 45B.

[0031] Fig.11 It is a cross-sectional view schematically showing the fuel filter 3 . DETAILED DESCRIPTION

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is a fuel filter that removes dust, water, etc. contained in fuel. The fuel filter can be installed in construction machinery, automobiles, etc.

[0033] The fuel filter is provided on the downstream side of the fuel tank. In addition, a pump is provided on the downstream side of the fuel filter. When the pump is operated, the fuel is supplied to the fuel filter 1, filtered by the fuel filter 1, and discharged from the fuel filter 1. Thereafter, the fuel is supplied to the internal combustion engine through the pump.

[0034] <First embodiment>

[0035] Figure 1 1 is a cross-sectional view schematically showing a fuel filter 1 as one embodiment of the present invention. The fuel filter 1 mainly includes a housing 30 having a filter case 10 and a head 20 , and a filter element 40 .

[0036] The filter housing 10 is formed of resin or metal, and includes a first housing 11 having a bottomed substantially cylindrical shape (here, a bottomed cylindrical shape) and a second housing 13 having a substantially cylindrical shape. In the present embodiment, the metal is, for example, stainless steel, and includes various types of metals having high corrosion resistance. It should be noted that the first housing 11 and the second housing 13 may also be a single component.

[0037] The first housing 11 is provided on the lower side (-z side) of the second housing 13. The first housing 11 has an opening at the upper end and is covered by a bottom surface 11a at the lower end. The space near the bottom surface 11a of the filter housing 10 is a water storage portion S4, and a drain plug 16 is provided on the bottom surface 11a. In addition, a float 51 is provided in the water storage portion S4 to enable confirmation of the water level.

[0038] The upper end of the filter case 10 is an open end 12. The head 20 is provided so as to cover the open end 12. The second case 13 is provided with a threaded portion 13a with which the threaded portion 22a provided on the cylindrical portion 22 of the head 20 is screwed.

[0039] The second housing 13 has a plate portion 14 . When the filter element 40 is placed on the plate portion 14 and the screw portion 22 a is screwed into the screw portion 13 a to attach the head 20 to the filter housing 10 , the filter element 40 is inserted into the head 20 and fixed inside the housing 30 .

[0040] An elastic member 52 such as an O-ring is provided between the plate-shaped portion 14 and the filter element 40, and an elastic member 53 such as an O-ring is provided between the head 20 and the filter element 40. Thus, the filter element 40 is fixed to the plate-shaped portion 14 and the head 20, and is sealed so that the fuel does not leak from between the filter element 40 and the plate-shaped portion 14 and between the filter element 40 and the head 20. In addition, an elastic member 54 such as an O-ring is provided between the second housing 13 and the head 20. Thus, the fuel is sealed so that the fuel does not leak from the housing 30.

[0041] The head 20 is formed of metal, supplies fuel to the filter element 40, and discharges the fuel filtered by the filter element 40. The head 20 includes a cylindrical portion 21 on which the filter element 40 is provided, and a cylindrical portion 22 provided in the second housing 13.

[0042] The space in the housing 30 is divided into two spaces by the filter element 40. The space between the housing 30 and the filter element 40 is a space S1, and the inside of the filter element 40 is a space S2, S3.

[0043] Figure 2 It is a cross-sectional view schematically showing the filter element 40 . Figure 3 1 is an exploded view schematically showing the filter element 40. The filter element 40 mainly includes a first filter 41, a second filter 42, and plates 43 and 44.

[0044] The first filter 41 mainly includes a first filter portion 41a, an inner tube 41b, and an outer tube 41c. The first filter portion 41a is formed by folding a plate-like material into a pleated shape (in this case, a cylindrical shape). The first filter portion 41a removes dust from the fuel and condenses water in the fuel. Specifically, the fuel passes through the first filter portion 41a, so that the water contained in the fuel condenses into water droplets with a larger diameter.

[0045] An inner cylinder 41b is provided along the inner circumference of the first filter 41a, and an outer cylinder 41c is provided along the outer circumference of the first filter 41a. A plurality of holes through which fuel can pass are provided in the inner cylinder 41b and the outer cylinder 41c. It should be noted that the inner cylinder 41b and the outer cylinder 41c are not essential.

[0046] The first filter 41 is provided with a plate 43 (corresponding to the first plate of the present invention) so as to cover the upper end (+z side), and a plate 44 is provided so as to cover the lower end (-z side). The plate 43 is provided with a cylindrical portion 43a at the center. The cylindrical portion 43a is inserted into the cylindrical portion 21, so that the filter element 40 is provided in the head 20.

[0047] The plate 43 has a cylindrical portion 43b disposed adjacent to the cylindrical portion 43a. The second filter 42 is disposed in the hollow portion 43d of the cylindrical portion 43b. The outer side of the second filter 42 in the filter element 40 is a space S2, and the inner side of the second filter 42 in the filter element 40 is a space S3.

[0048] The second filter 42 mainly includes a second filter portion 42a, a frame 42b, a cylindrical portion 42c, a plate 42d, and a grip portion 42e.

[0049] The second filter 42a is formed into a cylindrical shape by connecting both ends of a mesh-shaped thin plate. In addition, the second filter 42a has hydrophobicity. The frame 42b is provided on the second filter 42a and reinforces the second filter 42a.

[0050] The frame 42b, the cylindrical portion 42c, the plate 42d, and the gripping portion 42e are formed of, for example, resin. The frame 42b, the cylindrical portion 42c, the plate 42d, and the gripping portion 42e are preferably hydrophobic.

[0051] The cylindrical portion 42c (equivalent to the first end of the present invention) covers the end of the +z side of the second filter portion 42a. The cylindrical portion 42c is cylindrical and is detachably provided on the plate 43. The cylindrical portion 42c is provided with a through hole 42f that connects the hollow portion of the second filter portion 42a with the hollow portions 43c and 43d (equivalent to the first through hole of the present invention) of the cylindrical portions 43a and 43b. It should be noted that the shape of the cylindrical portion 42c is not limited to a cylindrical shape, and may be, for example, a plate shape.

[0052] The plate 42d (corresponding to the second end portion of the present invention) covers the end of the second filter portion 42a on the -z side. The plate 42d is plate-shaped and is provided with a gripping portion 42e.

[0053] The hollow portion 43c of the cylindrical portion 43a (corresponding to the small diameter portion of the present invention) is smaller in diameter than the hollow portion 43d of the cylindrical portion 43b (corresponding to the large diameter portion of the present invention). The cylindrical portion 43a and the hollow portion 43c are formed by the head 20 (refer to Figure 1 ) is sandwiched between the cylindrical portion 43b and the hollow portion 43d.

[0054] The second filter 42 (cylindrical portion 42c) is attachable to and detachable from the plate 43. Figure 3 As shown in the figure, the second filter 42 is inserted from the -z side toward the plate 43 (toward the +z direction) and the front end of the cylindrical portion 42c is brought into contact with the bottom surface of the hollow portion 43d, so that the cylindrical portion 42c is fixed inside the hollow portion 43d and the second filter 42 is attached to the plate 43. An elastic member (not shown) is provided between the hollow portion 43d and the cylindrical portion 42c, so that the second filter 42 does not fall from the plate 43.

[0055] The user grasps the grasping portion 42e and pulls out the second filter 42 in the -z direction (see Figure 3 ), the second filter 42 (cylindrical portion 42c) is removed from the hollow portion 43d.

[0056] return Figure 1 Instructions. Figure 1 In the figure, the flow of fuel is shown by the double-dashed arrow. The fuel guided from the fuel tank (not shown) to the fuel filter 1 is in a state before filtering. The fuel flows into the space S1 through the inflow portion (not shown) provided in the head 20. The fuel flowing into the space S1 passes through the first filter 41 to remove dust.

[0057] In addition, the fuel passes through the first filter 41 (first filter part 41a), so that the water contained in the fuel condenses and becomes water droplets with a larger diameter. Water has a larger specific gravity than oil, so basically the water droplets fall downward and accumulate in the water storage part S4. Even if the water droplets do not fall, the water droplets remain on the surface of the second filter 42 and do not pass through the second filter 42. In addition, the water droplets remaining on the surface of the second filter 42 grow as the amount of fuel passing through the second filter 42 increases, and when they become large in diameter, they fall downward and accumulate in the water storage part S4. In this way, the water contained in the fuel can be separated and removed.

[0058] The fuel flowing into the space S2 through the first filter 41 flows into the space S3 through the second filter 42. The fuel flowing out to the space S3 flows out of the fuel filter 1 through an outflow portion (not shown) of the head 20 and is guided to the engine (not shown).

[0059] When the filtration is repeated, the first filter part 41a becomes clogged, so the filter element 40 is replaced. First, the filter housing 10 and the head 20 are disassembled, and the filter element 40 is removed from the filter housing 10 and the head 20. Figure 3 As shown, the second filter 42 is removed from the plate 43 using the gripping portion 42e. Thus, the used first filter 41 and the plates 43 and 44 are removed. The second filter portion 42a is mesh-shaped (mesh), and clogging is unlikely to occur, so the second filter 42 can be reused.

[0060] The reused second filter 42 is attached to the new first filter 41 and the plates 43 and 44 to produce a new filter element 40 , and the new filter element 40 is attached to the housing 30 , thereby completing the replacement of the filter element 40 .

[0061] According to this embodiment, the fuel passes through the first filter 41a to convert the water contained in the fuel into large-diameter water droplets, which fall downward, and the surface of the second filter 42a captures the unfallen water droplets, thereby improving the separation performance of oil and water.

[0062] Furthermore, according to the present embodiment, the second filter 42 which is less likely to be clogged can be easily removed from the filter element 40, and the first filter 41a which is easily clogged can be easily replaced.

[0063] It should be noted that, in the present embodiment, the second filter 42 is removed from the filter element 40 by being pulled out from below, but the method of removing the second filter is not limited to this.

[0064] Figure 4 It is a cross-sectional view schematically showing a filter element 40A according to a modified example. Figure 5 1 is an exploded view showing the outline of the filter element 40A. The filter element 40A mainly includes a first filter 41 , a second filter 42A, and plates 43A and 44 .

[0065] The plate 43A (equivalent to the first plate of the present invention) is provided to cover the upper (+z side) end of the first filter 41. The plate 43A is provided with cylindrical portions 43a and 43e at the center. The cylindrical portion 43a is inserted into the cylindrical portion 21, and the filter element 40A is provided in the head 20.

[0066] The cylindrical portion 43e is provided adjacent to the cylindrical portion 43a. In addition, the plate-shaped portion 43f is provided adjacent to the cylindrical portion 43e. The second filter 42A is provided in the hollow portion 43g of the cylindrical portions 43a and 43e and the hollow portion 43h of the plate-shaped portion 43f. The hollow portion 43h has a smaller diameter than the hollow portion 43g.

[0067] The second filter 42A mainly includes a second filter portion 42a, a frame 42b, a cylindrical portion 42g, and a plate 42h. The frame 42b, the cylindrical portion 42g, and the plate 42h are formed of, for example, a hydrophobic resin.

[0068] The cylindrical portion 42g (equivalent to the first end of the present invention) covers the end of the second filter portion 42a on the +z side. The plate 42h (equivalent to the second end of the present invention) is plate-shaped and covers the end of the second filter portion 42a on the -z side. It should be noted that the shapes of the cylindrical portion 42g and the plate 42h are not limited to this.

[0069] The cylindrical portion 42 g is cylindrical and is provided with a through hole 42 i that communicates the hollow portion of the second filter portion 42 a with the hollow portions 43 g and 43 h (corresponding to the first through holes of the present invention).

[0070] The second filter 42A can be attached and detached relative to the plate 43A. Figure 5 As shown in the figure, the second filter 42A is inserted from the +z side toward the plate 43A (towards the -z direction), and the bottom surface of the cylindrical portion 42g is brought into contact with the bottom surface of the hollow portion 43g, so that the cylindrical portion 42g is fixed inside the hollow portion 43g, and the second filter portion 42a is inserted into the hollow portion 43h. Thus, the second filter 42A is mounted on the plate 43A. It should be noted that an elastic member (not shown) may also be provided between the hollow portion 43d and the cylindrical portion 42c.

[0071] The user grasps the cylindrical portion 42g and pulls out the second filter 42A in the +z direction, so that the second filter 42A is removed from the plate 43A. In addition, a grasping portion may be provided on the cylindrical portion 42g.

[0072] In this modified example, the fuel is passed through the first filter 41a, and the water contained in the fuel is converted into large-diameter water droplets, which are then dropped downward, and the surface of the second filter 42a is used to capture the water droplets that have not dropped, thereby improving the separation performance of oil and water. In addition, the second filter 42A, which is less likely to be clogged, is removed from the filter element 40A, and the first filter 41a, which is more likely to be clogged, can be easily replaced. In this modified example, the second filter 42A can be pulled out from the top for replacement, so that the fuel does not fall onto the user's hands or the surrounding area during replacement, and replacement is easy.

[0073] <Second embodiment>

[0074] In the first embodiment, the filter element 40 has a first filter 41 and a second filter 42, but the structure of the filter element is not limited thereto. In the second embodiment, the filter element has a baffle. Hereinafter, the fuel filter 2 of the second embodiment will be described. It should be noted that the same reference numerals are used for the same parts as those of the first embodiment and the modified example, and the description thereof will be omitted.

[0075] Figure 6 2 is a cross-sectional view schematically showing the fuel filter 2. The fuel filter 2 mainly includes a housing 30 having a filter case 10 and a head 20, and a filter element 40B.

[0076] When the threaded portion 22 a is screwed into the threaded portion 13 a and the head 20 is mounted on the filter case 10 , the filter element 40B is placed on the plate portion 14 and inserted into the cylindrical portion 21 , thereby fixing the filter element 40B inside the housing 30 .

[0077] Figure 7 4B is a cross-sectional view schematically showing the filter element 40B. The filter element 40B mainly includes a first filter 41 , a second filter 42A, plates 43B and 44 , and a blocking plate 45 .

[0078] The plate 43B (equivalent to the first plate of the present invention) is provided so as to cover the upper (+z side) end of the first filter 41 and the baffle plate 45. The plate 43B is provided with cylindrical portions 43a and 43i at the center. The cylindrical portion 43a is inserted into the cylindrical portion 21, so that the filter element 40B is provided in the head 20.

[0079] The cylindrical portion 43i is disposed adjacent to the cylindrical portion 43a. In addition, the plate-shaped portion 43f is disposed adjacent to the cylindrical portion 43e. The second filter 42A is detachably disposed in the hollow portion 43g of the cylindrical portions 43a and 43i and the hollow portion 43h of the plate-shaped portion 43f. The hollow portion 43h has a smaller diameter than the hollow portion 43g.

[0080] One end of the baffle plate 45 is provided on the outer peripheral surface 43j of the cylindrical portion 43i. In addition, the baffle plate 45 is provided between the first filter 41 and the second filter 42A.

[0081] Figure 8 is a diagram showing an overview of the baffle plate 45, Figure 8 (A) is the side view, Figure 8(B) is a cross-sectional view. The baffle plate 45 is a member formed into a cylindrical shape by connecting both ends of a plate-like member, and has an upper end 45a (end on the +z side) and a lower end 45b (end on the -z side) open. In the side surface 45c, the diameter of the upper end 45a is the largest, and the diameter of the lower end 45b is the smallest. No hole is provided in the side surface 45c, so the side surface 45c does not allow fuel to pass.

[0082] return Figure 7 The upper end 45a of the blocking plate 45 blocks the opening by abutting against the plate 43B. The blocking plate 45 has a tapered shape in which the diameter gradually decreases as it moves away from the plate 43B (upper end 45a).

[0083] The height of the baffle plate 45 is greater than that of the first filter 41. The upper end 45a of the baffle plate 45 is the same as that of the first filter 41, so the lower end 45b of the baffle plate 45 is located below the lower end of the first filter 41 (−z side).

[0084] return Figure 6 Instructions. Figure 6 In the figure, the flow of fuel is shown by the double-dashed arrow. The fuel guided from the fuel tank (not shown) to the fuel filter 2 flows into the space S1 through the inlet portion (not shown) provided in the head 20. The fuel flowing into the space S1 passes through the first filter 41 to remove dust, and flows into the space (space S5) between the baffle plate 45 and the first filter 41. In addition, the water contained in the fuel flowing into the space S5 passes through the first filter portion 41a, thereby agglomerating into water droplets with a larger diameter.

[0085] Since the baffle plate 45 does not allow the fuel to pass through, the fuel flowing into the space S5 flows downward (in the -z direction) along the baffle plate 45, and flows into the internal space (space S6) of the baffle plate 45 from the opening at the lower end (the end on the -z side) of the baffle plate 45. The fuel flowing into the space S6 flows into the space S3 through the second filter 42A, and flows out of the fuel filter 1 through the outflow portion (not shown) of the head 20.

[0086] Since the baffle plate 45 is provided, the fuel that has passed through the first filter 41 goes to the second filter 42A along the baffle plate 45 in a circuitous manner. Therefore, the amount of fuel movement increases under the action of the baffle plate 45, and water drops easily fall toward the water storage portion S4 by their own weight. In the present embodiment, the lower end 45b of the baffle plate 45 is located at a position lower than the lower end of the first filter 41 (-z side), so that all the fuel that has passed through the first filter 41 can flow downward along the baffle plate 45. Therefore, water drops easily fall toward the water storage portion S4 by their own weight.

[0087] Even if the water droplets do not fall, it is assumed that the water droplets remain on the surface of the second filter 42 and do not pass through the second filter 42, and fall at a stage where the diameter becomes large and accumulates in the water storage portion S4.

[0088] When the filtration is repeated, the first filter part 41a becomes clogged, so the filter element 40B is replaced. First, the filter case 10 and the head 20 are disassembled, and the filter element 40B is removed from the filter case 10 and the head 20. Then, the second filter 42A is removed from the plate 43B. The second filter 42A can be reused.

[0089] According to the present embodiment, the fuel passes through the first filter 41a to convert water contained in the fuel into large-diameter water droplets, and the fuel is detoured by the baffle plate 45 to increase the amount of movement, so that the water droplets fall more easily, and the oil-water separation performance is improved.

[0090] Furthermore, according to the present embodiment, since the second filter 42A that is less likely to be clogged can be removed, the first filter 41 a that is more likely to be clogged can be easily replaced.

[0091] It should be noted that, in the present embodiment, the baffle plate 45 has a tapered shape in which the diameter is the largest at the upper end 45a and decreases toward the lower end 45b, but the shape of the baffle plate is not limited thereto. For example, the baffle plate may also be a cylindrical shape without a tapered shape. However, in order to facilitate the downward flow of fuel, it is desirable that the baffle plate 45 has a tapered shape.

[0092] In addition, in the present embodiment, the lower end 45b of the baffle plate 45 is located at a position lower than the lower end of the first filter 41, but the height of the baffle plate is not limited thereto. For example, the lower end of the baffle plate may also be located between the lower end of the second filter 42 and the lower end of the first filter 41. Thus, the fuel that has passed through the first filter 41 does not directly contact the second filter 42, and the fuel can be detoured. In addition, regardless of the height of the baffle plate, as long as a baffle plate is provided adjacent to the plate 43B, the effect of detouring the fuel can be obtained. However, in order to maximize the amount of fuel movement, it is desirable to make the height of the baffle plate 45 as high as possible.

[0093] In the present embodiment, the baffle plate 45 is formed by connecting both ends of a plate-like member, and the side surface is flat. However, ribs, grooves, etc. may be provided on the side surface of the baffle plate.

[0094] Fig. 9 4 is a diagram showing an outline of a baffle plate 45A according to a modified example. Fig. 9 (A) is the side view, Fig. 9 (B) is a cross-sectional view. The baffle plate 45A is provided with a spiral rib 45d on the side surface 45c. Fig.101 is a diagram showing an overview of a baffle plate 45B of a modified example. The baffle plate 45B is provided with a spiral groove 45e on the side 45c. By providing the rib 45d or the groove 45e on the side 45c, the fuel can flow in a spiral along the rib 45d or the groove 45e. Therefore, the amount of fuel movement is further increased, and water droplets fall more easily.

[0095] <Third embodiment>

[0096] In the first embodiment, the filter element 40 has a first filter 41 and a second filter 42, but the structure of the filter element is not limited thereto. The third embodiment is a mode in which the filter element does not have the second filter 42. Hereinafter, the fuel filter 3 of the third embodiment will be described. It should be noted that the same reference numerals are used for the same parts as those of the first embodiment, the second embodiment, and their modified examples, and the description thereof will be omitted.

[0097] Fig.11 2 is a cross-sectional view schematically showing the fuel filter 3. The fuel filter 3 mainly includes a housing 30 having a filter case 10 and a head 20, and a filter element 40C. The filter element 40C mainly includes a first filter 41, plates 43B and 44, and a blocking plate 45A.

[0098] When the threaded portion 22 a is screwed into the threaded portion 13 a and the head 20 is mounted on the filter case 10 , the filter element 40C is placed on the plate portion 14 and the filter element 40C (the cylindrical portion 43 a ) is inserted into the cylindrical portion 21 , thereby fixing the filter element 40C inside the housing 30 .

[0099] exist Fig.11 In the figure, the flow of fuel is shown by the double-dashed arrow. The fuel guided from the fuel tank (not shown) to the fuel filter 3 flows into the space S1 through the inlet portion (not shown) provided in the head 20. The fuel flowing into the space S1 passes through the first filter 41 to remove dust, and flows into the space (space S5) between the baffle plate 45 and the first filter 41. In addition, the water contained in the fuel flowing into the space S5 passes through the first filter portion 41a, and is condensed into water droplets with a larger diameter.

[0100] The baffle plate 45 does not allow the fuel to pass through, so the fuel that has flowed into the space S5 flows downward (in the -z direction) along the side surface 45c while spirally rotating along the rib 45d, and flows into the space S6 from the opening at the lower end (the end on the -z side) of the baffle plate 45. The fuel that has flowed into the space S6 flows out of the fuel filter 3 through the outflow portion (not shown) of the head 20.

[0101] When the filtration is repeated, the first filter part 41a becomes clogged, so the filter element 40C is replaced. First, the filter case 10 and the head 20 are disassembled, and the filter element 40C is removed from the filter case 10 and the head 20. Then, a new filter element 40C is installed in the housing 30, thereby completing the replacement of the filter element 40C.

[0102] According to the present embodiment, by providing the baffle plate 45A, the amount of fuel that has passed through the first filter 41 increases, and water droplets easily fall toward the water storage portion S4 by their own weight. In the present embodiment, the lower end 45b of the baffle plate 45 is located at a position lower than the lower end of the first filter 41 (-z side), so the amount of fuel that has passed through the first filter 41 is large, and oil and water can be separated without using the second filter 42.

[0103] It should be noted that, in the present embodiment, the filter element 40C has the baffle plate 45A, but it is not limited to the baffle plate 45A, and the baffle plate 45 or the baffle plate 45B can be used. In addition, the shape and height of the baffle plate of the filter element 40C are not limited thereto. However, since the second filter 42 is not used, it is desirable to make the height of the baffle plate 45A as high as possible.

[0104] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the specific structure is not limited to the present embodiment, and also includes design changes within the scope of the main purpose of the present invention. For example, the above-mentioned embodiments are described in detail to make the present invention easy to understand, and are not necessarily limited to having all the structures described. In addition, a part of the structure of the embodiment can be replaced with the structure of other embodiments, and in addition, other structures can be added, deleted, replaced, etc. to the structure of the embodiment.

[0105] In addition, "substantially" refers to the concept of not only including strictly identical situations, but also including errors and deformations to the extent that the sameness is not lost. For example, "cylindrical shape" is not limited to the situation of being strictly cylindrical, and includes, for example, the concept of being able to be regarded as equivalent to a cylindrical shape. In addition, for example, in the case of only being orthogonal, parallel, consistent, etc., it includes not only the situation of being strictly orthogonal, parallel, consistent, etc., but also the situation of being substantially parallel, substantially orthogonal, substantially consistent, etc.

[0106] In addition, "nearby" refers to an area including a certain range (which can be set arbitrarily) near the reference position. For example, in the case of "near the end", it refers to an area in a certain range near the end, which is a concept that may or may not include the end.

[0107] Description of Reference Numerals

[0108] 1, 2, 3: Fuel filter

[0109] 10: Filter housing

[0110] 11: First shell

[0111] 11a: Bottom

[0112] 12: Open end

[0113] 13: Second shell

[0114] 13a: Threaded part

[0115] 14: Plate-shaped part

[0116] 16: Drain plug

[0117] 20: Head

[0118] 21, 22: Cylindrical part

[0119] 22a: Threaded part

[0120] 30: Shell

[0121] 40, 40A, 40B, 40C: Filter element

[0122] 41: First filter

[0123] 41a: First filter unit

[0124] 41b: Inner tube

[0125] 41c: outer cylinder

[0126] 42, 42A: Second filter

[0127] 42a: Second filter unit

[0128] 42b: Framework

[0129] 42c, 42g: cylindrical part

[0130] 42d, 42h: board

[0131] 42e: Grip

[0132] 42f, 42i: Through hole

[0133] 43, 43A, 43B: Plate

[0134] 43a, 43b, 43e, 43i: cylindrical part

[0135] 43c, 43d, 43g, 43h: Hollow part

[0136] 43f: plate-shaped part

[0137] 43j: Outer surface

[0138] 44: Board

[0139] 45, 45A, 45B: Blocking plate

[0140] 45a: Top

[0141] 45b: Lower end

[0142] 45c: Side

[0143] 45d: Rib

[0144] 45e: Slot

[0145] 51: Buoy

[0146] 52, 53, 54: elastic components.

Claims

1. A fuel filter comprising: a housing having a substantially cylindrical filter case having an opening at one end and being covered at the other end, and a head provided on the filter case so as to cover the opening; and a filter element disposed in the inner space of the housing and capable of being attached to and detached from the housing, The fuel filter is characterized in that The filter element comprises: a first filter having a cylindrical first filter portion formed by folding a sheet-like filter material into a pleated shape; a second filter disposed inside the first filter portion; and a first plate provided with the first filter and the second filter. The second filter comprises: a second filter portion formed into a cylindrical shape by connecting both ends of a mesh-shaped thin plate; a first end portion covering a first end of the second filter portion; and a second end portion covering a second end of the second filter portion on a side opposite to the first end. The first plate is disposed on the head and has a first through hole formed in the center. The first end portion is disposed on the first plate and is provided with a second through hole that connects the hollow portion of the second filter portion with the first through hole. The first plate and the first end portion are attachable and detachable.

2. The fuel filter according to claim 1, characterized in that The first through hole has a large diameter portion into which the first end portion is inserted and a small diameter portion having a smaller diameter than the large diameter portion. The small diameter portion is sandwiched between the head and the large diameter portion, A grip portion is provided at the second end portion.

3. The fuel filter according to claim 1 or 2, characterized in that: The fuel filter includes a cylindrical baffle plate provided between the first filter and the second filter. One end of the blocking plate is disposed on the first plate.

4. A fuel filter comprising: a housing having a substantially cylindrical filter case having an opening at one end and being covered at the other end, and a head provided on the filter case so as to cover the opening; and a filter element disposed in the inner space of the housing and capable of being attached to and detached from the housing, The fuel filter is characterized in that The filter element comprises: a first filter having a cylindrical first filter portion formed by folding a sheet-like filter material into a pleated shape; a cylindrical baffle plate disposed inside the first filter; and a first plate provided with the first filter and the baffle plate. The first plate is disposed on the head and has a first through hole formed in the center. The first through hole connects the hollow portion of the baffle plate to the outflow portion provided in the head.

5. The fuel filter according to claim 3 or 4, characterized in that: The blocking plate has a tapered shape with a diameter gradually decreasing as it moves away from the first plate.

6. The fuel filter according to any one of claims 3 to 5, characterized in that The height of the blocking plate is greater than or equal to the height of the first filter unit.

7. The fuel filter according to any one of claims 3 to 6, characterized in that The baffle plate has spiral grooves or ribs formed on its outer peripheral surface.

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