Fuel filter

Abstract

To provide a fuel filter capable of improving the separation performance of oil and water with a structure facilitating the exchange of a filtering material.SOLUTION: A fuel filter is equipped with a housing 30 that has a generally cylindrical filter case 10, a head 20 provided in the filter case so as to cover an opening portion, and a filter element 40 that can be attached / detached to / from the housing 30. The filter element 40 has a cylindrical first filter 41 formed by folding a sheet-like filtering material in a pleated shape, a second filter 42 provided inside the first filter 41, and a first plate 43 provided with the first filter 41 and the second filter 42. The first plate 43 is provided at the head 20, has a first through-hole formed at a center, and is provided with a second through-hole allowing communication between a hollow portion of the second filter 42 and the first through-hole. The first plate 43 and a first end portion can be attached / detached.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 discloses a fuel filter including a first filter medium with a central axis substantially aligned along a vertical direction and a second filter medium provided inside the first inner cylinder. In the first inner cylinder of this 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 other than the first region. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-203091 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the invention described in Patent Document 1, cylindrical pleated filter materials made by pleating plate-shaped materials are used for the first and second filter materials, which makes the filter elements expensive. Since filter elements are consumables, it is desirable that they are inexpensive and easy to replace, but ease of replacement alone is not enough, and since they are fuel filters, they must maintain high oil and water separation performance.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a fuel filter that has a configuration that allows easy replacement of the filter material while achieving high oil and water separation performance. [Means for solving the problem]

[0006] A fuel filter according to the present invention includes, for example, a housing having a filter case in a substantially cylindrical shape with an opening at one end and a covered 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, the filter element including a first filter having a cylindrical first filtering portion formed by folding a sheet-like filter material into a pleated shape, a second filter provided inside the first filtering portion, and a filter element having a filter element that is detachable from the first filter and the second filter. and a first plate on which a filter is provided, the second filter having a second filtering section formed in a cylindrical shape by connecting both ends of a mesh-like thin plate, a first end covering a first end of the second filtering section, and a second end covering a second end of the second filtering section opposite the first end, the first plate being provided on the head and having a first through hole formed in the center, the first end being provided on the first plate, and a second through hole communicating with a hollow portion of the second filtering section and the first through hole being provided, and the first plate and the first end being detachable.

[0007] According to the fuel filter of the present invention, the filter element has a first plate provided on the head, and a first filter and a second filter provided on the first plate, and the second filter is provided inside the first filtering section. The first filter has a cylindrical first filtering section formed by folding a sheet-like filter material into a pleated shape, and the second filter has a second filtering section formed into a cylindrical shape by connecting both ends of a mesh-like thin plate. The first end of the second filter is detachably provided on the first plate. As a result, the fuel passes through the first filtering section, and the moisture contained in the fuel is turned into large-diameter water droplets that fall downward, and the water droplets that do not fall are captured on the surface of the second filtering section, thereby improving the oil-water separation performance. In addition, the second filter, which is not easily clogged, can be easily removed, and the first filtering section, which is easily clogged, can be easily replaced.

[0008] The first through hole may have a large diameter portion into which the first end is inserted and a small diameter portion having a diameter smaller than that of the large diameter portion, the small diameter portion being sandwiched between the head and the large diameter portion, and a grip portion may be provided at the second end portion, which allows a user to grasp and use the grip portion to pull the second filter out of the first plate, making it easy to remove the second filter.

[0009] The oil-water separation device may further include a cylindrical baffle plate provided between the first filter and the second filter, the baffle plate having one end provided on the first plate, whereby the baffle plate increases the amount of fuel moving and makes it easier for water droplets to fall, thereby improving the oil-water separation performance.

[0010] A fuel filter according to another aspect of the present invention is a fuel filter including, for example, a housing having a substantially cylindrical filter case having an opening at one end and a covered 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, the filter element including a first filter having a cylindrical first filtering section formed by folding a sheet-like filter material into a pleated shape, a cylindrical baffle plate provided inside the first filter, and a first plate provided with the first filter and the baffle plate, the first plate being provided on the head and having a first through hole formed in the center, the first through hole communicating a hollow portion of the baffle plate with an outflow portion provided on the head.

[0011] According to the fuel filter of the present invention, the filter element has a first plate provided on the head, and a first filter and a baffle plate provided on the first plate, and the baffle plate is provided inside the first filtering section. This increases the amount of fuel moving and makes it easier for water droplets to fall, thereby improving the oil-water separation performance.

[0012] The baffle plate may have a taper such that the diameter gradually decreases with increasing distance from the first plate, which facilitates fuel flow downward along the baffle plate.

[0013] The height of the baffle plate may be equal to or greater than the height of the first filter section, thereby increasing the amount of fuel movement and making it easier for water droplets to fall.

[0014] The baffle plate may have a spiral groove or rib formed on its outer circumferential surface, which further increases the amount of fuel moving and makes it easier for water droplets to fall. Effect of the Invention

[0015] According to the present invention, it is possible to improve the oil / water separation performance while having a configuration that allows easy replacement of the filter medium. [Brief description of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view showing an outline of a fuel filter 1 according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing an outline of a filter element 40. [Diagram 3] FIG. 2 is an exploded view showing a schematic configuration of a filter element 40. [Figure 4] FIG. 2 is a cross-sectional view showing an outline of a filter element 40A. [Diagram 5] FIG. 2 is an exploded view showing a schematic configuration of a filter element 40A. [Figure 6] FIG. 2 is a cross-sectional view showing an outline of a fuel filter 2. [Figure 7] FIG. 4 is a cross-sectional view showing an outline of a filter element 40B. [Figure 8] 1A and 1B are diagrams showing an outline of a baffle plate 45, in which (A) is a side view and (B) is a cross-sectional view. [Figure 9] 1A and 1B are diagrams showing an outline of a baffle plate 45A, in which (A) is a side view and (B) is a cross-sectional view. [Figure 10] FIG. 13 is a diagram showing an outline of a baffle plate 45B. [Figure 11] FIG. 2 is a cross-sectional view showing an outline of a fuel filter 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The present invention relates to a fuel filter that removes dust, moisture, etc. contained in fuel. The fuel filter can be installed in construction machinery, automobiles, etc.

[0018] The fuel filter is provided downstream of the fuel tank. A pump is provided downstream of the fuel filter. When the pump is operated, fuel is supplied to the fuel filter 1, filtered by the fuel filter 1, and discharged from the fuel filter 1. The fuel is then supplied to the internal combustion engine through the pump.

[0019] <First embodiment> 1 is a cross-sectional view showing an outline of a fuel filter 1 according to 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.

[0020] The filter case 10 is made of resin or metal, and has a first case 11 having a generally cylindrical shape with a bottom (here, a cylindrical shape with a bottom) and a generally cylindrical second case 13. In this embodiment, the metal is, for example, stainless steel, and includes various types of metals having high corrosion resistance. The first case 11 and the second case 13 may be a single component.

[0021] The first case 11 is provided below (on the -z side) the second case 13. The first case 11 has an opening at its upper end, and its lower end is covered by a bottom surface 11a. The space near the bottom surface 11a of the filter case 10 is a water storage section S4, and a drain plug 16 is provided on the bottom surface 11a. A float 51 is provided in the water storage section S4 so that the water level can be confirmed.

[0022] The upper end of the filter case 10 is an open end 12. A head 20 is provided to cover the open end 12. The second case 13 is provided with a threaded portion 13a into which a threaded portion 22a provided on a cylindrical portion 22 of the head 20 is screwed.

[0023] The second case 13 has a plate-shaped portion 14. When the filter element 40 is placed on the plate-shaped portion 14, and the threaded portion 22a is screwed into the threaded portion 13a to attach the head 20 to the filter case 10, the filter element 40 is inserted into the head 20, and the filter element 40 is fixed inside the housing 30.

[0024] 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. This fixes the filter element 40 to the plate-shaped portion 14 and the head 20, and seals the gap between the filter element 40 and the plate-shaped portion 14 and the gap between the filter element 40 and the head 20 so that fuel does not leak. In addition, an elastic member 54 such as an O-ring is provided between the second case 13 and the head 20. This seals the housing 30 so that fuel does not leak.

[0025] The head 20 is made of metal, supplies fuel to the filter element 40, and discharges the fuel filtered by the filter element 40. The head 20 has a cylindrical portion 21 in which the filter element 40 is provided, and a cylindrical portion 22 provided in the second case 13.

[0026] The space within the housing 30 is divided into two spaces by the filter element 40. Of these two spaces, the space between the housing 30 and the filter element 40 is space S1, and the interior of the filter element 40 is spaces S2 and S3.

[0027] Fig. 2 is a cross-sectional view showing a schematic of the filter element 40. Fig. 3 is an exploded view showing a schematic of the filter element 40. The filter element 40 mainly has a first filter 41, a second filter 42, and plates 43 and 44.

[0028] The first filter 41 mainly includes a first filtering section 41a, an inner cylinder 41b, and an outer cylinder 41c. The first filtering section 41a is formed by pleating (creating pleats) a plate-shaped material into a tubular shape (here, a cylindrical shape). The first filtering section 41a removes dust from the fuel and condenses the moisture in the fuel. Specifically, as the fuel passes through the first filtering section 41a, the moisture contained in the fuel condenses to form water droplets with a larger diameter.

[0029] An inner cylinder 41b is provided along the inner peripheral surface of the first filtering section 41a, and an outer cylinder 41c is provided along the outer peripheral surface of the first filtering section 41a. The inner cylinder 41b and the outer cylinder 41c are provided with a large number of holes through which the fuel can pass. Note that the inner cylinder 41b and the outer cylinder 41c are not essential.

[0030] 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 so as to cover the lower end (-z side). A cylindrical portion 43a is provided in the center of the plate 43. The filter element 40 is provided in the head 20 by inserting the cylindrical portion 43a into the inside of the cylindrical portion 21.

[0031] The plate 43 has a cylindrical portion 43b provided adjacent to the cylindrical portion 43a. The second filter 42 is provided in a hollow portion 43d of the cylindrical portion 43b. Within the filter element 40, the outside of the second filter 42 is a space S2, and the inside of the second filter 42 is a space S3.

[0032] The second filter 42 mainly includes a second filtering portion 42a, a frame 42b, a cylindrical portion 42c, a plate 42d, and a grip portion 42e.

[0033] The second filtering section 42a is formed in a cylindrical shape by connecting both ends of a mesh-like thin plate. The second filtering section 42a has water repellency. The frame 42b is provided on the second filtering section 42a and reinforces the second filtering section 42a.

[0034] The frame 42b, the cylindrical portion 42c, the plate 42d, and the gripping portion 42e are made of, for example, a resin, and it is desirable that the frame 42b, the cylindrical portion 42c, the plate 42d, and the gripping portion 42e have water repellency.

[0035] The cylindrical portion 42c (corresponding to the first end of the present invention) covers the end of the second filtering portion 42a on the +z side. 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 communicates the hollow portion of the second filtering portion 42a with the hollow portions 43c and 43d (corresponding to the first through hole of the present invention) of the cylindrical portions 43a and 43b. The shape of the cylindrical portion 42c is not limited to a cylindrical shape, and may be, for example, a plate shape.

[0036] The plate 42d (corresponding to the second end of the present invention) covers the end of the second filtering section 42a on the -z side. The plate 42d is in a plate shape and is provided with a gripping section 42e.

[0037] A hollow portion 43c (corresponding to a small diameter portion of the present invention) of the cylindrical portion 43a has a smaller diameter than a hollow portion 43d (corresponding to a large diameter portion of the present invention) of the cylindrical portion 43b. The cylindrical portion 43a and the hollow portion 43c are sandwiched between the head 20 (see FIG. 1) and the cylindrical portion 43b and the hollow portion 43d.

[0038] The second filter 42 (cylindrical portion 42c) is detachable from the plate 43. As shown in FIG. 3, the second filter 42 is inserted from the -z side toward the plate 43 (in the +z direction) and the tip of the cylindrical portion 42c is brought into contact with the bottom surface of the hollow portion 43d, whereby 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 to prevent the second filter 42 from falling off the plate 43.

[0039] When the user grasps grip portion 42e and pulls out second filter 42 in the -z direction (see the outlined arrow in FIG. 3), second filter 42 (cylindrical portion 42c) is removed from hollow portion 43d.

[0040] Returning to the explanation of FIG. 1, the flow of fuel is indicated by dashed double-dashed arrows in FIG. 1. The fuel guided from a fuel tank (not shown) to the fuel filter 1 is in a state before being filtered. The fuel flows into the space S1 through an inlet portion (not shown) provided in the head 20. The fuel that has flowed into the space S1 passes through the first filter 41, where dust is removed.

[0041] Furthermore, as the fuel passes through the first filter 41 (first filtering section 41a), the water contained in the fuel condenses and becomes water droplets with a larger diameter. Since water has a larger specific gravity than oil, the water droplets basically fall downward and accumulate in the water storage section S4. Even if the water droplets do not fall, they remain on the surface of the second filter 42 and do not pass through the second filter 42. Furthermore, the water droplets that remain on the surface of the second filter 42 grow as the amount of fuel passing through the second filter 42 increases and, when they reach a larger diameter, they fall downward and accumulate in the water storage section S4. This allows the water contained in the fuel to be separated and removed.

[0042] The fuel that has passed through the first filter 41 and flowed into the space S2 passes through the second filter 42 and flows into the space S3. The fuel that has flowed out into the space S3 flows out of the fuel filter 1 through an outlet portion (not shown) of the head 20, and is led to the engine (not shown).

[0043] Repeated filtration causes clogging of the first filtering section 41a, and therefore the filter element 40 is replaced. First, the filter case 10 and the head 20 are disassembled, and the filter element 40 is removed from the filter case 10 and the head 20. Then, as shown in FIG. 3, the second filter 42 is removed from the plate 43 using the gripping part 42e. This allows the used first filter 41 and the plates 43, 44 to be taken out. The second filtering section 42a is mesh-like and does not easily become clogged, so the second filter 42 can be reused.

[0044] The second filter 42 to be reused is attached to the new first filter 41 and plates 43, 44 to produce a new filter element 40, and the new filter element 40 is then attached to the housing 30, thereby completing the replacement of the filter element 40.

[0045] According to this embodiment, the fuel is passed through the first filtration section 41a to convert the water contained in the fuel into large-diameter droplets, which then fall downward. The water droplets that do not fall are captured on the surface of the second filtration section 42a, thereby improving the oil-water separation performance.

[0046] Furthermore, according to this embodiment, the second filter 42, which is less likely to become clogged, can be easily removed from the filter element 40, and the first filtering portion 41a, which is more likely to become clogged, can be easily replaced.

[0047] In the present embodiment, the second filter 42 is removed from the filter element 40 by pulling it out from below, but the manner in which the second filter is removed is not limited to this.

[0048] Fig. 4 is a cross-sectional view showing a schematic of a filter element 40A according to a modified example. Fig. 5 is an exploded view showing a schematic of the filter element 40A. The filter element 40A mainly has a first filter 41, a second filter 42A, and plates 43A and 44.

[0049] Plate 43A (corresponding to the first plate of the present invention) is provided so as to cover the end of the upper side (+z side) of first filter 41. Plate 43A is provided with cylindrical portions 43a, 43e in the center. Filter element 40A is provided in head 20 by inserting cylindrical portion 43a into cylindrical portion 21.

[0050] The cylindrical portion 43e is provided adjacent to the cylindrical portion 43a. A plate-shaped portion 43f is provided adjacent to the cylindrical portion 43e. The second filter 42A is provided in a hollow portion 43g of the cylindrical portions 43a and 43e and in a hollow portion 43h of the plate-shaped portion 43f. The hollow portion 43h has a smaller diameter than the hollow portion 43g.

[0051] The second filter 42A mainly includes a second filtering 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 made of, for example, a water-repellent resin.

[0052] The cylindrical portion 42g (corresponding to a first end of the present invention) covers the end of the second filtering portion 42a on the +z side. The plate 42h (corresponding to a second end of the present invention) is plate-shaped and covers the end of the second filtering portion 42a on the -z side. Note that the shapes of the cylindrical portion 42g and the plate 42h are not limited to this.

[0053] The cylindrical portion 42g is cylindrical, and is provided with a through hole 42i that communicates the hollow portion of the second filtering portion 42a with the hollow portions 43g and 43h (corresponding to the first through hole of the present invention).

[0054] The second filter 42A is detachable from the plate 43A. As shown in FIG. 5, the second filter 42A is inserted from the +z side toward the plate 43A (in 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, whereby the cylindrical portion 42g is fixed inside the hollow portion 43g and the second filtering portion 42a is inserted into the hollow portion 43h. In this way, the second filter 42A is attached to the plate 43A. Note that an elastic member (not shown) may be provided between the hollow portion 43d and the cylindrical portion 42c.

[0055] The user grips cylindrical portion 42g and pulls out second filter 42A in the +z direction, whereby second filter 42A is removed from plate 43A. Note that a gripping portion may be provided on cylindrical portion 42g.

[0056] In this modification, the fuel passes through the first filtering section 41a to turn the water contained in the fuel into large droplets, which then fall downward, while the water droplets that do not fall are captured on the surface of the second filtering section 42a, thereby improving the oil-water separation performance. In addition, the second filter 42A, which is not easily clogged, can be removed from the filter element 40A, and the first filtering section 41a, which is easily clogged, can be easily replaced. In addition, in this modification, the second filter 42A can be replaced by pulling it out from above, so that fuel does not drip onto the user's hands or the surrounding area during replacement, making replacement easy.

[0057] <Second embodiment> In the first embodiment, the filter element 40 has the first filter 41 and the second filter 42, but the configuration of the filter element is not limited to this. In the second embodiment, the filter element has a baffle plate. A fuel filter 2 according to the second embodiment will be described below. Note that the same reference numerals are used to denote the same parts as those in the first embodiment and the modified example, and description thereof will be omitted.

[0058] 6 is a cross-sectional view showing an outline of 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.

[0059] When the screw portion 22a is screwed into the screw portion 13a and the head 20 is attached to the filter case 10, the filter element 40B is placed on the plate-shaped portion 14 and the filter element 40B is inserted into the tubular portion 21, thereby fixing the filter element 40B inside the housing 30.

[0060] 7 is a cross-sectional view showing an outline of the filter element 40 B. The filter element 40 B mainly includes a first filter 41, a second filter 42 A, plates 43 B and 44 , and a baffle plate 45 .

[0061] Plate 43B (corresponding to the first plate of the present invention) is provided so as to cover the upper (+z side) ends of first filter 41 and baffle plate 45. Plate 43B is provided with cylindrical portions 43a, 43i in the center. Filter element 40B is provided in head 20 by inserting cylindrical portion 43a into cylindrical portion 21.

[0062] The cylindrical portion 43i is provided adjacent to the cylindrical portion 43a. Furthermore, the plate-shaped portion 43f is provided adjacent to the cylindrical portion 43e. The second filter 42A is detachably provided in the hollow portion 43g of the cylindrical portions 43a and 43i and in the hollow portion 43h of the plate-shaped portion 43f. The hollow portion 43h has a smaller diameter than the hollow portion 43g.

[0063] An outer circumferential surface 43j of the cylindrical portion 43i is provided with one end of a baffle plate 45. The baffle plate 45 is provided between the first filter 41 and the second filter 42A.

[0064] 8 is a diagram showing an outline of baffle plate 45, where (A) is a side view and (B) is a cross-sectional view. 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). Upper end 45a has the largest diameter, and lower end 45b has the smallest diameter. Since side 45c has no holes, side 45c does not allow fuel to pass through.

[0065] Returning to the description of Fig. 7, the opening of the upper end 45a of the baffle plate 45 is blocked by abutting against the plate 43B. The baffle plate 45 has a taper such that the diameter gradually decreases with increasing distance from the plate 43B (upper end 45a).

[0066] Moreover, the height of the baffle plate 45 is equal to or greater than the height of the first filter 41. Since an upper end 45a of the baffle plate 45 and an upper end of the first filter 41 are flush with each other, a lower end 45b of the baffle plate 45 is positioned lower (on the -z side) than the lower end of the first filter 41.

[0067] Returning to the explanation of FIG. 6, in FIG. 6, the flow of fuel is indicated by the two-dot chain line arrow. Fuel guided from a fuel tank (not shown) to the fuel filter 2 flows into the space S1 through an inlet section (not shown) provided in the head 20. The fuel that flows into the interior of the space S1 passes through the first filter 41, where dust is removed, and the fuel flows into the space between the baffle plate 45 and the first filter 41 (space S5). In addition, moisture contained in the fuel that flows into the space S5 condenses into larger diameter water droplets as it passes through the first filtering section 41a.

[0068] Since the baffle plate 45 does not allow fuel to pass therethrough, the fuel that has flowed 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 an 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 passes through the second filter 42A and flows into the space S3, and then flows out of the fuel filter 1 via the outflow portion (not shown) of the head 20.

[0069] Since the baffle plate 45 is provided, the fuel that has passed through the first filter 41 makes a detour along the baffle plate 45 toward the second filter 42A. Therefore, the amount of fuel moving is increased by the baffle plate 45, and water droplets tend to fall under their own weight toward the water storage section S4. In this embodiment, the lower end 45b of the baffle plate 45 is located lower (on the -z side) than the lower end of the first filter 41, so that all of the fuel that has passed through the first filter 41 can flow downward along the baffle plate 45. Therefore, water droplets tend to fall under their own weight toward the water storage section S4.

[0070] Even if the water droplets do not fall, they remain on the surface of the second filter 42, do not pass through the second filter 42, and fall when their diameter becomes large and accumulate in the water reservoir S4.

[0071] Repeated filtration causes clogging of the first filtering portion 41a, and therefore 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 is reusable.

[0072] According to this embodiment, the fuel is passed through the first filtration section 41a to convert the water contained in the fuel into large-diameter droplets, and the fuel is diverted by the baffle plate 45 to increase the amount of movement, which makes it easier for the water droplets to fall, thereby improving the oil-water separation performance.

[0073] Furthermore, according to this embodiment, the second filter 42A, which is less likely to become clogged, can be removed, so that the first filtering portion 41a, which is more likely to become clogged, can be easily replaced.

[0074] In this embodiment, the baffle plate 45 has a taper such that the diameter is largest at the upper end 45a and decreases toward the lower end 45b, but the shape of the baffle plate is not limited to this. For example, the baffle plate may have a cylindrical shape without a taper. However, in order to facilitate the downward flow of fuel, it is desirable for the baffle plate 45 to have a taper.

[0075] In addition, in this embodiment, the lower end 45b of the baffle plate 45 is located below the lower end of the first filter 41, but the height of the baffle plate is not limited to this. For example, the lower end of the baffle plate may be located between the lower end of the second filter 42 and the lower end of the first filter 41. This prevents the fuel that has passed through the first filter 41 from directly hitting the second filter 42, and allows the fuel to be diverted. Furthermore, regardless of the height of the baffle plate, as long as the baffle plate is provided adjacent to the plate 43B, the effect of diverting the fuel can be obtained. However, in order to increase the amount of fuel movement as much as possible, it is desirable to make the height of the baffle plate 45 as high as possible.

[0076] In this embodiment, the baffle plate 45 is formed by connecting both ends of a plate-like member, and the side surface is flat, but ribs, grooves, etc. may be provided on the side surface of the baffle plate.

[0077] FIG. 9 is a diagram showing an outline of a baffle plate 45A according to a modified example, where (A) is a side view and (B) is a cross-sectional view. The baffle plate 45A has a spiral rib 45d on a side surface 45c. FIG. 10 is a diagram showing an outline of a baffle plate 45B according to a modified example. The baffle plate 45B has a spiral groove 45e on a side surface 45c. By providing the rib 45d or the groove 45e on the side surface 45c, the fuel can flow in a spiral shape along the rib 45d or the groove 45e. Therefore, the amount of fuel movement is further increased, and water droplets are more likely to fall.

[0078] <Third embodiment> In the first embodiment, the filter element 40 has the first filter 41 and the second filter 42, but the configuration of the filter element is not limited to this. In the third embodiment, the filter element does not have the second filter 42. A fuel filter 3 according to the third embodiment will be described below. Note that the same reference numerals are used to denote parts similar to those in the first embodiment, the second embodiment, and the modified examples thereof, and descriptions thereof will be omitted.

[0079] 11 is a cross-sectional view showing an outline of 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 baffle plate 45A.

[0080] When the screw portion 22a is screwed into the screw portion 13a and the head 20 is attached to the filter case 10, the filter element 40C is placed on the plate-shaped portion 14, and the filter element 40C (cylindrical portion 43a) is inserted into the tubular portion 21, thereby fixing the filter element 40C inside the housing 30.

[0081] In Fig. 11, the flow of fuel is indicated by dashed two-dot arrows. Fuel guided from a fuel tank (not shown) to the fuel filter 3 flows into space S1 through an inlet section (not shown) provided in the head 20. The fuel that has flowed into the interior of space S1 passes through the first filter 41, where dust is removed, and the fuel then flows into the space between the baffle plate 45 and the first filter 41 (space S5). Furthermore, moisture contained in the fuel that has flowed into space S5 condenses into larger-diameter water droplets as it passes through the first filtering section 41a.

[0082] Because the baffle plate 45 does not allow fuel to pass through, the fuel that has flowed into the space S5 flows downward (in the -z direction) along the side surface 45c while rotating in a spiral shape along the rib 45d, and flows into the space S6 from an 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 via an outlet portion (not shown) of the head 20.

[0083] Repeated filtration causes clogging of the first filtering portion 41a, and therefore 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. Thereafter, a new filter element 40C is attached to the housing 30, completing the replacement of the filter element 40C.

[0084] According to this embodiment, by providing baffle plate 45A, the amount of fuel that has passed through first filter 41 increases, and water droplets tend to fall by their own weight toward water storage section S4. In this embodiment, lower end 45b of baffle plate 45 is located lower (-z side) than the lower end of first filter 41, so that the amount of fuel that moves is large, and oil and water can be separated without using second filter 42.

[0085] In the present embodiment, filter element 40C has baffle plate 45A, but is not limited to baffle plate 45A, and baffle plate 45 or baffle plate 45B may be used. The shape and height of the baffle plate of filter element 40C are not limited to this. However, since second filter 42 is not used, it is desirable to make the height of baffle plate 45A as high as possible.

[0086] Although the embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes within the scope of the gist of the present invention are also included. For example, the above example has been described in detail to clearly explain the present invention, and is not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of the embodiment with the configuration of another embodiment, and it is also possible to add, delete, or replace other configurations to the configuration of the embodiment.

[0087] In addition, "approximately" is a concept that includes not only the case of being strictly identical, but also an error or deformation that does not lose the identity. For example, "cylindrical shape" is not limited to the case of being strictly cylindrical, but is a concept that includes, for example, a case that can be regarded as being identical to a cylindrical shape. In addition, for example, when expressing orthogonal, parallel, coincident, etc., it includes not only strictly orthogonal, parallel, coincident, etc., but also approximately parallel, approximately orthogonal, approximately coincident, etc.

[0088] In addition, "vicinity" means including a certain range (which can be determined arbitrarily) near a reference position. For example, in the case of "near an end," it is a concept indicating a certain range of an area near the end, which may or may not include the end. [Explanation of symbols]

[0089] 1, 2, 3: Fuel filter 10: Filter case 11: Case 1 11a: Bottom 12: Open end 13: Case 2 13a: Threaded section 14: Plate-shaped part 16: Drain plug 20: Head 21, 22: Cylindrical part 22a: Threaded section 30: Housing 40, 40A, 40B, 40C: Filter elements 41: First filter 41a: 1st filtration section 41b: Inner cylinder 41c: Outer cylinder 42, 42A: Second filter 42a: 2nd filtration section 42b: Frame 42c, 42g: Cylindrical part 42d, 42h: Plate 42e: Grip part 42f, 42i: Through hole 43, 43A, 43B: Plate 43a, 43b, 43e, 43i: cylindrical portion 43c, 43d, 43g, 43h: Hollow part 43f: Plate-shaped part 43j: Outer surface 44: Plate 45, 45A, 45B: Baffle plate 45a: Upper end 45b: Bottom end 45c: Side 45d: Rib 45e : Groove 51: Float 52, 53, 54: Elastic member

Claims

1. A housing having a substantially cylindrical filter case with an opening at one end and the other end covered, and a head provided on the filter case so as to cover the opening, A filter element provided in the internal space of the housing and detachable from the housing, In a fuel filter comprising: The filter element includes a first filter having a cylindrical first filtration part formed by folding a sheet-like filter medium into pleats, a second filter provided inside the first filtration part, and a first plate provided with the first filter and the second filter, The second filter has a second filtration part formed by connecting both ends of a net-like thin plate into a cylindrical shape, a first end part covering the first end of the second filtration part, and a second end part covering the second end of the second filtration part opposite to the first end, The first plate is provided on the head, and a first through hole is formed in the center, The first end part is provided on the first plate, and a second through hole is provided to communicate the hollow part of the second filtration part and the first through hole, The first plate and the first end part are detachable from each other A fuel filter characterized by the above.

2. The first through hole has a large-diameter part into which the first end part is inserted and a small-diameter part having a diameter smaller than that of the large-diameter part, The small-diameter part is sandwiched between the head and the large-diameter part, A gripping part is provided on the second end part The fuel filter according to claim 1, characterized by the above.

3. Comprising a cylindrical baffle plate provided between the first filter and the second filter, One end of the baffle plate is provided on the first plate The fuel filter according to claim 1, characterized by the above.

4. A housing having a substantially cylindrical filter case with an opening at one end and the other end covered, and a head provided on the filter case so as to cover the opening, A filter element provided in the internal space of the housing and detachable from the housing, In a fuel filter comprising: The filter element includes a first filter having a cylindrical first filtration part formed by folding a sheet-like filter medium into pleats, a cylindrical baffle plate provided inside the first filter, and a first plate provided with the first filter and the baffle plate, The first plate is provided on the head, and a first through hole is formed in the center, The first through-hole communicates the hollow portion of the baffle plate and the outflow portion provided in the head. A fuel filter characterized by the above. **Claim 5** The baffle plate has a taper in which the diameter gradually decreases as it moves away from the first plate. The fuel filter according to claim 3 or 4, characterized by the above. **Claim 6** The height of the baffle plate is equal to or greater than the height of the first filtration portion. The fuel filter according to claim 3 or 4, characterized by the above. **Claim 7** A spiral groove or rib is formed on the outer peripheral surface of the baffle plate. The fuel filter according to claim 3 or 4, characterized by the above.

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