JP2019203416A - Fuel filter device - Google Patents

Abstract

To efficiently prevent clogging of a filter in a fuel filter device.SOLUTION: A fuel filter device 10 according to the disclosure includes a filter 1, a casing 2, and a heater 3. The filter 1 is formed in a cylinder having chrysanthemum shape cross section, and has a pleat 8 extending in a cylinder axial direction. The casing 2 has hollow cylindrical shape in which the filter 1 is accommodated. The heater 3 is axial, is extended from a bottom surface side of the casing 2 in a the cylinder axial direction of the filter 1, and is inserted in an interspace of the pleat 8.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fuel filter device for filtering fuel of an internal combustion engine.

  2. Description of the Related Art Conventionally, a technique for removing impurities and moisture in fuel by inserting a fuel filter device in a fuel supply path of an internal combustion engine (engine) is known. 2. Description of the Related Art In fuel filter devices for automobiles, a fuel supply system in which a filter element is housed in a casing and fuel that has passed through the filter element is supplied to an engine is widely used. The filter element is detachably attached to the casing, and can be replaced during maintenance (see Patent Document 1).

  On the other hand, depending on environmental conditions, paraffin in the fuel may be waxed in the casing, and sludge having low fluidity may accumulate on the filter element. Sludge is likely to occur when diesel fuel is used in a cold environment. In recent years, it has been confirmed that sludge is likely to be generated when biodiesel fuel containing biological oil is used even in a room temperature environment. When the amount of accumulated sludge increases, the fuel pressure decreases due to clogging of the filter element, and normal operation of the internal combustion engine is hindered.

  In response to such a problem, a temperature raising system for a fuel filter device using exhaust heat of an internal combustion engine has been studied. For example, it has been proposed to raise the temperature of the entire fuel filter device by reintroducing relatively high-temperature recirculated fuel that is recirculated from the internal combustion engine to the fuel tank into the fuel filter device. Thereby, it becomes difficult to precipitate wax, and generation | occurrence | production of sludge can be suppressed (refer patent document 2).

JP 2013-148055 A JP 2014-020221 A

  However, the temperature raising system of the fuel filter device based on the exhaust heat of the internal combustion engine cannot be used unless the internal combustion engine is warmed up. Therefore, when starting in a cold environment, it takes time to raise the temperature of the entire fuel filter device, and the operation of the internal combustion engine may become unstable. Moreover, as shown in Patent Document 1, in a filter element having a chrysanthemum cross-sectional shape, wax is likely to deposit inside the pleats formed on the peripheral surface thereof. In the conventional fuel filter device, the wax accumulated in such a gap is not easily melted, and clogging of the filter may not be sufficiently solved.

  One of the objects of the present case was invented in view of the above problems, and is to provide a fuel filter device that efficiently suppresses clogging of a filter. It should be noted that the present invention is not limited to this purpose, and is an operational effect that is derived from each configuration shown in “Mode for Carrying Out the Invention” to be described later. Can be positioned as a purpose.

(1) The disclosed fuel filter device includes a filter having a cross section formed in a chrysanthemum shape and having pleats extending in a cylinder axis direction. Moreover, a hollow cylindrical casing in which the filter is accommodated is provided. Furthermore, an axial heater is provided that extends from the bottom surface of the casing in the cylinder axis direction of the filter and is inserted into the gap between the pleats.
(2) It is preferable that the heater is erected from the vicinity of the bottom surface of the casing within a range below the center in the height direction of the filter.

(3) It is preferable that the heaters are arranged at equal intervals in the circumferential direction of the filter.
(4) It is preferable that the heater has a first heater inserted into the pleat gap outside the filter and a second heater inserted into the pleat inside the filter.
(5) It is preferable that the first heater and the second heater are arranged so that the direction in which the first heater is present with respect to the cylindrical shaft is different from the direction in which the second heater is present with respect to the cylindrical shaft.

(6) It is preferable to provide an inflow port that is disposed on the inner peripheral surface of the casing and allows the fuel to flow from the inner peripheral surface toward the filter.
(7) It is preferable to provide a fuel passage connected to the inflow port and formed in an upward slope toward the inner peripheral surface.
(8) It is preferable that the fuel passage is formed in a direction in which the fuel flows into the gap between the pleats.

  By adopting a structure in which a shaft-like heater is inserted into the gap between the pleats of the filter, the fluidity of the fuel in the casing can be improved, and the accumulation of wax in the gap between the pleats can be suppressed. . Thereby, clogging of the filter can be efficiently suppressed.

It is a side view which shows the fuel filter apparatus of this embodiment. It is a typical longitudinal section of a fuel filter device. It is a disassembled perspective view for demonstrating the internal structure of a fuel filter apparatus. It is a top view for demonstrating the structure of a heater. It is typical sectional drawing for demonstrating the structure of a fuel channel and an inflow port. (A), (B) is a longitudinal cross-sectional view which shows the convection in the inside of a fuel filter apparatus. It is a schematic diagram for demonstrating the filter as a modification.

  Hereinafter, a fuel filter device 10 as an embodiment will be described with reference to the drawings. The fuel filter device 10 is a filter for filtering liquid fuel of a diesel engine mounted on an automobile. However, the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment. Each configuration of the present embodiment can be implemented with various modifications without departing from the spirit thereof. Alternatively, they can be selected as necessary, or can be appropriately combined.

[1. Constitution]
The fuel filter device 10 has a function of filtering the fuel introduced from the side surface and discharging the fuel from the upper surface. FIG. 1 shows the attitude of the fuel filter device 10 when mounted on an automobile, and the vertical direction in the figure corresponds to the vertical direction when the vehicle is mounted. Of the side surfaces of the fuel filter device 10, an inlet pipe 11 is connected in the vicinity of the lower end portion, and an outlet pipe 12 is connected in the vicinity of the upper end portion. The inlet pipe 11 is connected to a fuel pipe (return fuel pipe) returning from the fuel tank or the engine. The outlet pipe 12 is connected to an engine and a supply pump (a pump device for pressurizing fuel). A drain for draining is provided at the lower end of the fuel filter device 10.

  As shown in FIG. 2, the filter 1 is accommodated in the casing 2 of the fuel filter device 10 and can be replaced as necessary. The inside of the casing 2 has a hollow cylindrical shape, and when the filter 1 is replaced, the filter 1 is attached and detached along the cylindrical axis C of the casing. The filter 1 is a pleated filter element formed in a cylindrical shape having a chrysanthemum cross section. The material of the filter 1 is paper, synthetic fiber, non-woven fabric, metal (metal fiber, metal mesh) or the like. A specific shape of the filter 1 is illustrated in FIG.

  If the rough shape of the filter 1 is similar to a cylindrical shape coaxial with the casing 2, the cylindrical surface is formed in a shape in which a flat filter member is folded in a bellows shape. Such a folding structure increases the contact area between the filtration member and the fuel passing therethrough, thereby improving the filtration performance. Here, each pleated portion formed by folding a flat filter member into a bellows shape is referred to as a pleat 8. The flow direction of the fuel filtered by the filter 1 is a direction from the outside to the inside of the pleat 8 (a direction from the outer peripheral side to the inner peripheral side of the filter 1).

  The cross-sectional shape of the filter 1 shown in FIG. 3 can also be defined as follows. First, an inner circle corresponding to the inner peripheral portion and an outer circle corresponding to the outer peripheral portion are drawn concentrically. Next, a plurality of line segments are set at equal intervals on the inner circle. In the case of the filter 1 shown in FIG. 3, the number of line segments is 30. Although the length of a line segment is arbitrary, it is preferable to set it as long as an appropriate gap is provided between adjacent line segments. Similarly, on the outer circle, the same number of line segments as the inner circle are set at equal intervals. Then, a chrysanthemum-shaped cross-sectional shape is obtained by alternately connecting the line segments on the inner circle and the line segments on the outer circle.

  The filter 1 of the present embodiment has a large number of pleats 8 extending in a direction parallel to the cylinder axis C (that is, in the cylinder axis direction). The filter 1 shown in FIG. 3 is provided with 30 pleats 8. The cross-sectional shape when the filter 1 is cut along a plane perpendicular to the cylinder axis C is the same even if the position of the filter 1 in the height direction is different. Further, the gap 9 sandwiched between the two pleats 8 adjacent to each other also has a structure extending in the cylinder axis direction. Hereinafter, the structure of the fuel filter device 10 will be described on the assumption that the cylinder axis C of the casing 2 is the same as the cylinder axis C of the filter 1.

  As shown in FIG. 3, a cylindrical inner cylinder 13 with an upper bottom and a lower bottom open is disposed inside the filter 1. The inner cylinder 13 has a plurality of inner cylinder holes 14 through which the fuel filtered by the filter 1 passes. An upper surface plate 15 is provided on the upper surface side of the filter 1, and a lower surface plate 18 is provided on the lower surface side. The filter 1 is accommodated in the casing 2 while being sandwiched between the upper plate 15 and the lower plate 18. Of the space sandwiched between the upper surface plate 15 and the lower surface plate 18, the outside of the filter 1 is a space into which fuel before filtration is introduced, and the inside of the filter 1 is a space filled with fuel after filtration. .

  The top plate 15 is provided with a donut disk-shaped disk part 16 having a circular hole formed in the center, and a fixed wall 17 standing in a circle so as to surround the hole of the disk part 16. The diameter of the disk portion 16 is a dimension corresponding to the inner diameter of the casing 2, and is provided so as to be slidable in the direction of the cylinder axis C along the inner peripheral surface 25 of the casing 2. Further, the lower surface of the disk portion 16 is a portion that contacts the upper surface of the filter 1. The fixed wall 17 is formed in a cylindrical shape that is in sliding contact with the outer surface of the inner cylinder 13. The inner diameter of the fixed wall 17 is a dimension corresponding to the outer diameter of the inner cylinder 13. Thus, the inner cylinder 13 is supported so as to be insertable / removable with respect to the top plate 15.

  The bottom plate 18 is also provided with a donut disk-shaped disk part 19 having a circular hole formed in the center, and a fixed wall 21 standing in a circle around the hole of the disk part 19. The diameter of the disk portion 19 is the same as that of the disk portion 16 of the top plate 15. The inner diameter of the fixed wall 21 is also the same as the inner diameter of the fixed wall 17 of the top plate 15. On the other hand, the central hole of the disk portion 19 is set to have a smaller diameter than the hole of the upper surface plate 15. Thereby, an abutting portion 22 that abuts the lower end of the inner cylinder 13 is formed inside the fixed wall 21. A plurality of small holes 20 are drilled in the disk portion 19. The position of the small hole 20 is an opening for vertically passing a heater 3 described later, and is set so as to correspond to the arrangement position of the heater 3.

  The heater 3 is a heater that is inserted into a gap 9 between pleats 8 formed on the side surface of the filter 1. The heater 3 is erected from the vicinity of the bottom surface of the casing 2 within a range below the center in the height direction of the filter 1. That is, the lower half range (or a narrower range) of the filter 1 is set as the heating range of the heater 3. If the height dimension of the filter 1 shown in FIG. 2 is H, the position of the upper end of the heater 3 is set below the position of the distance (2 / H) from the lower end surface of the filter 1. The heater 3 includes at least a portion extending from the bottom surface side of the casing 2 in the cylinder axis direction of the filter 1.

  The heater 3 shown in FIG. 3 has two annular portions 23 and 24 developed along a plane orthogonal to the cylinder axis C, and a plurality of shaft portions extending from various locations in the annular portions 23 and 24. 4,5. A PTC (Positive Temperature Coefficient) heater and a heating wire heater are built in the shaft portions 4 and 5, and a power supply wiring material is built in the annular portions 23 and 24. Here, of the two annular portions 23 and 24, the inner one is called the first annular portion 23, and the outer one is called the second annular portion 24. Moreover, what is connected to the 1st annular part 23 among the axial parts 4 and 5 is called the 1st axial part 4 (1st heater), and what is connected to the 2nd annular part 24 is the 2nd axial part. 5 (second heater).

  As shown in FIG. 4, the layouts of the first shaft portion 4 and the second shaft portion 5 are rotationally symmetric with respect to the cylinder axis C. Further, the positions of the first shaft portion 4 and the second shaft portion 5 are different from each other so that the existence directions (directions) of the first shaft portion 4 and the second shaft portion 5 are different with respect to the cylinder axis C in a top view. Is set. Each of the first shaft portion 4 and the second shaft portion 5 is arranged at equal intervals in the circumferential direction of the filter 1. Preferably, as shown in FIG. 4, the layout is such that all of the first shaft portion 4 and the second shaft portion 5 are equally spaced. Thereby, the distribution of the heat generated by the heater 3 is substantially uniform in the circumferential direction of the filter 1. The size, diameter, and heat generation amount of the first shaft portion 4 may not be the same as the dimension, diameter, and heat generation amount of the second shaft portion 5.

  As shown in FIG. 5, the first shaft portion 4 is inserted into the gap 9 of the pleat 8 outside the filter 1. The heat generated in the first shaft portion 4 greatly contributes to the temperature rise of the fuel existing outside the filter 1. On the other hand, the second shaft portion 5 is inserted into the pleat 8 inside the filter 1. The heat generated in the second shaft portion 5 greatly contributes to the temperature rise of the fuel existing inside the filter 1. In addition, when the fuel filter device 10 is used in a cold environment, it is considered that the temperature outside the filter 1 tends to be lower than the inside inside the filter 1. Therefore, the performance of the heater 3 may be set so that the amount of heat generated in the second shaft portion 5 is larger than that in the first shaft portion 4.

  An inlet 6 through which fuel flows from the inner peripheral surface 25 toward the filter 1 is provided on the inner peripheral surface 25 of the casing 2. As shown in FIG. 5, the position of the inflow port 6 is a position where the straight line and the inner peripheral surface 25 intersect (or when the straight line connecting the cylinder axis C and the first shaft part 4 is drawn in a top view (or Set in the vicinity thereof. In the present embodiment, as shown in FIG. 2, a plurality of inflow ports 6 having different positions in the height direction are provided. In other words, the plurality of inflow ports 6 are continuously provided at intervals in the vertical direction (height direction).

  The fuel passage 7 connected to each inflow port 6 is formed in an upward gradient toward the inner peripheral surface 25. Thereby, the flow direction of the fuel from the inflow port 6 into the casing 2 is obliquely upward. Further, the horizontal direction (extending direction) of the fuel passage 7 is set to the direction in which the fuel flows into the gap 9 of the pleat 8 as shown in FIG. As a result, the fuel easily flows into the innermost part of the gap 9. The shape of the fuel passage 7 in FIG. 5 does not necessarily have to be a straight line passing through the cylinder axis C.

[2. Action / Effect]
FIG. 6A is a schematic view of the AA cross section of FIG. The fuel is introduced from the inlet 6 into the casing 2 through the fuel passage 7 and flows toward the gap 9 of the pleat 8. Such a fuel flow facilitates melting of the wax accumulated in the gap 9. Further, outside the filter 1, the fuel density distribution is biased by the heat generation of the first shaft portion 4, and convection as shown by the black arrow in FIG. Thereby, the warmed fuel spreads all over the inside of the casing 2 and the melting of the wax is promoted.

  FIG. 6B is a schematic view of the BB cross section of FIG. Inside the filter 1, the fuel density distribution is biased by the heat generation of the second shaft portion 5, and convection as shown by the black arrow in FIG. 6B occurs. Thereby, the warmed fuel spreads all over the inside of the casing 2 and the melting of the wax is promoted. Further, the convection direction inside the filter 1 is opposite to the convection direction outside the filter 1. Thereby, the heat of the heater 3 is diffused into the casing 2 in a short time, and the melting of the wax is promoted.

  (1) In the fuel filter device 10 described above, a plurality of pleats 8 are provided on the surface of the filter 1, and the shaft-like heater 3 is inserted into a gap between the pleats 8. With such a structure, heat diffusibility and fuel fluidity in the casing 2 can be enhanced. Further, by disposing the heater 3 in the gap 9 of the pleat 8, even if wax is accumulated in the gap 9, it becomes easy to melt the wax. Therefore, the accumulation of wax in the gap 9 can be suppressed, and the clogging of the filter 1 can be efficiently suppressed.

  (2) As shown in FIG. 2, the heater 3 is disposed in a range below the center of the filter 1 in the height direction. Thereby, it is possible to easily generate convection of the fuel in the gap or inside of the pleat 8. That is, since the fuel warmed by the heater 3 circulates efficiently in the casing 2, the temperature distribution of the fuel can be made uniform in a short time. When wax is generated inside the casing 2 in a cold environment, the distribution becomes higher in the lower part of the casing 2. Therefore, by heating the lower half range of the filter 1 with the heater 3, the wax can be efficiently melted without wasting power excessively.

  (3) As shown in FIG. 4, the heaters 3 of the present embodiment are arranged at equal intervals in the circumferential direction of the filter 1. For example, the first shaft portion 4 and the second shaft portion 5 are arranged at equal intervals in the circumferential direction of the filter 1. With such a structure, the heat distribution of the fuel in the casing 2 can be leveled in the circumferential direction of the filter 1, and clogging of the filter 1 can be efficiently suppressed.

  (4) A first shaft portion 4 is provided outside the filter 1, and a second shaft portion 5 is provided inside the filter 1. The first shaft portion 4 is inserted into the gap 9 of the pleat 8 and acts to fix the position of the filter 1. Similarly, the second shaft portion 5 is inserted into the pleat 8 and acts to fix the position of the filter 1. In this way, by adopting a structure in which the heater 3 is inserted inside and outside the filter 1, it is possible to suppress the displacement of the filter 1 due to the vibration of the vehicle body, and to improve the stability of the filter 1.

  (5) Also, the positions of the first shaft portion 4 and the second shaft portion 5 so that the directions of existence of the first shaft portion 4 and the second shaft portion 5 are different with respect to the cylinder axis C in a top view. Is set. Thereby, the temperature difference between the inside and outside of the filter 1 can be reduced, and clogging of the filter 1 can be efficiently suppressed. In addition, when a part of filter 1 is heated locally, the deterioration of the part may progress easily. On the other hand, the filter 1 does not have such a concern, and the life of the filter 1 can be extended.

  (6) As shown in FIG. 2, the inner peripheral surface 25 of the casing 2 is provided with an inlet 6 through which fuel flows toward the filter 1. Thus, by providing the fuel inlet on the inner peripheral surface 25 of the casing 2, the wax on the surface of the filter 1 can be washed away by utilizing the momentum of the fuel flow, and the filter 1 can be effectively clogged. Can be suppressed. Moreover, in this embodiment, the inflow port 6 is continuously arranged at intervals in the vertical direction (height direction). Thereby, the wax accumulated in the gap 9 of the pleat 8 can be pushed out efficiently.

  (7) Further, the fuel passage 7 connected to each inflow port 6 is formed in an upward gradient toward the inner peripheral surface 25 of the casing 2. Thereby, the distribution direction of the fuel flowing into the casing 2 is obliquely upward, and the wax on the surface of the filter 1 can be more effectively poured off. Therefore, clogging of the filter 1 can be efficiently suppressed.

  (8) Further, since the fuel passage 7 is formed in a direction in which the fuel flows into the gap 9 of the pleat 8, it becomes easy to allow the fuel to flow into the innermost part of the gap 9, and the wax is made to flow more effectively. be able to. Therefore, clogging of the filter 1 can be efficiently suppressed.

[3. Modified example]
The above-described embodiment is merely an example, and there is no intention of excluding various modifications and technical applications that are not explicitly described in the present embodiment. For example, the above-described fuel filter device 10 can be used as a filter for filtering various liquids such as gasoline engine fuel (gasoline), engine oil, engine cooling water, fuel additives, and exhaust gas purification additives. it can. Further, it can be used not only for internal combustion engines mounted on automobiles but also for filtering fuel of internal combustion engines installed in ships, aircrafts, factories and the like.

  In the above-described embodiment, the filter 1 having the cross-sectional shape illustrated in FIG. 5 is illustrated, but the shape of the filter 1 is not limited thereto. For example, as shown in FIG. 7, a filter 1 having a shape (density type) in which the pleats 8 are folded back on the radially outer side may be used. By adopting a structure in which the shaft-like heater 3 is inserted into at least the gap 9 of the pleat 8, the same effects as those of the above-described embodiment can be obtained.

1 Filter 2 Casing 3 Heater 4 First shaft (first heater)
5 Second shaft (second heater)
6 Inlet 7 Fuel passage 8 Pleated 9 Clearance 10 Fuel filter device C Cylinder shaft

Claims (8)

A filter having a cross section formed into a chrysanthemum-shaped cylinder and having pleats extending in the cylinder axis direction;
A hollow cylindrical casing in which the filter is accommodated;
An axial heater that extends from the bottom side of the casing in the cylinder axis direction of the filter and is inserted into the gap between the pleats;
A fuel filter device comprising: 2. The fuel filter device according to claim 1, wherein the heater is erected from the vicinity of the bottom surface of the casing in a range below the center in the height direction of the filter. The fuel filter device according to claim 1 or 2, wherein the heaters are arranged at equal intervals in a circumferential direction of the filter. The said heater has the 1st heater inserted in the clearance gap between the said pleats on the outer side of the said filter, and the 2nd heater inserted on the inside of the said pleat on the inner side of the said filter. The fuel filter device according to any one of? The first heater and the second heater are disposed so that a direction in which the first heater is present with respect to the cylindrical shaft is different from a direction in which the second heater is present with respect to the cylindrical shaft. 4. The fuel filter device according to 4. The fuel filter device according to any one of claims 1 to 5, further comprising an inflow port disposed on an inner peripheral surface of the casing and configured to circulate fuel from the inner peripheral surface toward the filter. . The fuel filter device according to claim 6, further comprising a fuel passage connected to the inflow port and formed in an upward gradient toward the inner peripheral surface. The fuel filter device according to claim 7, wherein the fuel passage is formed in a direction in which the fuel flows into the gap between the pleats.

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