JP4302726B2 - Fuel filter device - Google Patents

Description

  The present invention relates to an improvement in a fuel filter device used by being attached to a fuel suction port in a fuel tank.

  The fuel in the fuel tank is transferred to the internal combustion engine through a suction pipe or the like disposed in the fuel tank. In order to remove water from the fuel thus transferred and prevent foreign matter from being fed into the fuel pump, a filter device is attached to the fuel suction port of the suction pipe. An example of such a filter device is disclosed in Patent Document 1.

  Such a filter device has a bag-like filter body having an internal space communicating with a fuel suction port. Such a filter body has a nonwoven fabric layer formed by the spunbond method inside the outermost layer of the extruded mesh, and further has a nonwoven fabric layer formed by the melt blown method inside.

  However, in such a filter device, the difference between the average pore diameter of the nonwoven fabric layer formed by the spunbond method and the average pore diameter of the nonwoven fabric layer formed by the melt blown method tends to be too large. The tendency became more prominent as the filtration accuracy was improved. In other words, since it is difficult to reduce the fiber diameter of the fibers constituting the nonwoven fabric layer formed by the spunbond method, the average diameter of the pores of the formed nonwoven fabric layer, that is, the limit to making the eyes finer have. On the other hand, in the melt blown method, the average diameter of pores of the formed nonwoven fabric layer can be appropriately reduced because the fiber diameter of the fibers constituting the formed nonwoven fabric layer can be appropriately reduced. . Therefore, in the filter body of Patent Document 1, in order to improve the filtration accuracy, the average diameter of the pores of the nonwoven fabric layer formed by the melt blown method is reduced, but if this is reduced. The difference from the average pore diameter of the nonwoven fabric layer formed by the spunbond method becomes so large that many dusts contained in the fuel to be captured are captured by the nonwoven fabric layer formed by the melt blown method. Become. (That is, the filtration gradient becomes steep, and the nonwoven fabric layer formed by the spunbond method does not properly serve as a prefilter.)

For this reason, the filter device according to Patent Document 1 is formed by the melt blown method as the filtration accuracy is increased, that is, as finer dust contained in the fuel is captured. It becomes difficult to clog the nonwoven fabric layer over a long period of time. When such clogging increases, the fuel suction pressure increases (that is, the pressure loss increases), and the load on the fuel pump increases.
JP 2000-246026 A

  The main problem to be solved by the present invention is to prevent clogging of the filter body as much as possible while increasing the filtration accuracy of the filter body constituting this type of filter device as much as possible.

In order to solve the above problems, the present invention is characterized in that the fuel filter device includes the following elements (1) to (7).
(1) A filter device having a bag-like filter body and attached so as to communicate the internal space of the filter body with a fuel suction port in the fuel tank,
(2) This filter device has an interval forming member that is housed in the filter body and keeps the filter body in a bag shape that is always inflated,
(3) The filter body has two or more layers of non-woven fabric layers formed by laminating constituent materials in the form of sheets or mats,
(4) While the pores of one of the two or more nonwoven fabric layers is in the range of 1.7 μm or more and 16.6 μm or less,
(5) The average diameter of the pores of one nonwoven fabric layer positioned outside the nonwoven fabric layer having the pores in the range of 1.7 μm or more and 16.6 μm or less makes the filtration gradient gentle, It is larger than the average diameter of the pores of the nonwoven fabric layer having the pores in the range of 1.7 μm to 16.6 μm,
(6) Moreover, the nonwoven fabric layer having pores in the range of 1.7 μm or more and 16.6 μm or less and the nonwoven fabric layer positioned outside this to moderate the filtration gradient are formed by the melt blown method,
(7) Further, the average diameter of the pores of the nonwoven fabric layer having the pores in the range of 1.7 μm or more and 16.6 μm or less, and the pores of the nonwoven fabric layer positioned more outward than this to moderate the filtration gradient The difference from the average diameter is 40 μm or less.

  According to this invention, it is possible to prevent clogging of the filter body as long as possible while increasing the filtration accuracy of the filter body constituting the filter device as much as possible.

  Hereinafter, one of the best modes for carrying out the present invention will be described with reference to FIGS.

  Here, FIG. 1 is a configuration diagram showing a state in which the filter device F is attached to the fuel suction port P in the fuel tank T, and FIG. 3 shows a filter body 1 constituting the filter device F. 1 shows an example of a cross-sectional configuration. (In FIG. 3, only the cross-sectional configuration of the upper surface side and the lower surface side of the filter body 1 is shown, and the description of the interval forming member 3 housed in the filter body 1 is omitted.) FIG. It is the graph which showed the property of these three nonwoven fabric layers 12 ... 12 in the filter body 1 comprised by providing the three nonwoven fabric layers 12 ... 12 formed by these.

  The fuel filter device F according to this embodiment is attached to a fuel suction port P in a fuel tank T of an automobile or a two-wheeled vehicle, and water is transferred to the fuel transferred to the internal combustion engine through the fuel suction port P. It is intended to prevent foreign substances from entering.

  Typically, such a filter device F is attached to this fuel inlet P of a suction pipe having a fuel inlet P located in the fuel tank T.

  Further, the fuel is transferred to the internal combustion engine through the fuel suction port P by a fuel pump disposed in the fuel tank T or a fuel pump disposed outside the fuel tank T.

  The filter device F has a filter body 1 having a bag shape. The filter device F is attached to the fuel suction port P so that the internal space 10 of the bag-shaped filter body 1 communicates with the fuel suction port P.

  Specifically, in the illustrated example, the filter device F has one end portion 20 as a connection end portion to the fuel suction port P and the other end portion 21 formed in the filter body 1. A plastic cylindrical socket body 2 is provided as an end connected to the communication hole 11, and the internal space 10 of the filter body 1 is communicated with the fuel suction port P by the cylindrical socket body 2. is there.

  Further, in the illustrated example, the filter device F has a gap forming member 3 that is housed in the filter body 1 and keeps the filter body 1 in a bag shape that is always inflated.

  Specifically, in the illustrated example, the gap forming member 3 has its upper surface in contact with the upper inner surface of the bag-shaped filter body 1 and its lower surface on the lower inner surface of the filter body 1. The filter body 1 is inserted into the filter body 1 so that the filter body 1 is always kept in an inflated bag shape. The interval forming member 3 is formed with a plurality of fuel passage portions (not shown) extending between the upper surface and the lower surface.

  Further, the filter body 1 has two or more nonwoven fabric layers 12, 12,.

At the same time, the average diameter of pores of a certain nonwoven fabric layer 12 and the average diameter of pores of another nonwoven fabric layer 12 are not matched,
Among these two or more nonwoven fabric layers 12, 12,..., The average diameter of the pores of the nonwoven fabric layer 12 located on the inner side of the filter body 1 is the pore size of the nonwoven fabric layer 12 located on the outer side. It is designed to be smaller than the average diameter,
Moreover, these nonwoven fabric layers 12 are formed by a melt blown method so that the filtration gradient becomes gentle.

  Thus, according to the filter device F, the nonwoven fabric layer 12 positioned on the outer side of the filter body 1 captures dust having a relatively large particle size, and the nonwoven fabric positioned on the inner side of the filter body 1. Dust and the like having a relatively small particle diameter can be captured by the layer 12, and dust and the like can be appropriately removed from the sucked fuel in a state where clogging of the filter body 1 is difficult to occur. That is, when the nonwoven fabric layer 12 is made into one layer, dust of all particle diameters must be captured by the nonwoven fabric layer 12, and the filter body 1 is likely to be clogged over time. Further, when the filter body 1 is constituted by two or more layers of nonwoven fabric layers 12, 12... That do not differ greatly in pores, all the dust and the like are formed by the nonwoven fabric layer 12 that is located most outside the filter body 1. Similarly, clogging of the filter body 1 is likely to occur over time because it is trapped, but in this filter device F, clogging of the filter body 1 can be made difficult to occur over a long period of time.

  Further, according to the melt blown method, the wire diameter of the synthetic fiber constituting the nonwoven fabric layer 12 can be effectively narrowed, and the average pore diameter of the nonwoven fabric layer 12 can be adjusted to be appropriately small. So that there is no extreme difference between the average diameter of the pores of the nonwoven fabric layer 12 located on the inner side and the average diameter of the pores of the nonwoven fabric layer 12 located on the outer side, that is, the filter body 1 It is possible to prevent the filtration gradient from becoming steep. Thereby, the function as a pre-filter with respect to the nonwoven fabric layer 12 located inside by the nonwoven fabric layer 12 located outside the filter body 1 can be appropriately given. That is, when the nonwoven fabric layer 12 formed by the spunbond method is located outside the filter body 1 and the nonwoven fabric layer 12 formed by the melt blown method is located inside the filter body 1, the filter body 1 is configured. In the spunbond method, it is difficult to reduce the wire diameter of the synthetic fiber constituting the nonwoven fabric layer 12, so that the rigidity (stiffness) of the nonwoven fabric layer 12 can be secured, but the average diameter of pores of the nonwoven fabric layer 12 is difficult to reduce, and is formed by the melt blown method. The non-woven fabric layer 12 is entrusted with a lot of trapping of dust and the like, and as a result, clogging of the non-woven fabric layer 12 formed by the melt blown method positioned inward tends to occur over time. In the filter device F according to the embodiment, the non-woven fabric layer 12 positioned more inward of the filter body 1 has flat pores. The non-woven fabric layer 12 positioned on the outer side is appropriately preliminarily treated with a non-woven fabric layer 12 located outside of the non-woven fabric layer 12 so as to capture only the debris whose particle size is expected to be captured depending on the diameter. Since it can be captured, clogging of the nonwoven fabric layer 12 positioned more inward can be made as difficult as possible.

Among the two or more nonwoven fabric layers 12, 12... Formed by the melt blown method,
The average diameter of the pores of the nonwoven fabric layer located in the innermost part of the filter body 1 is in the range of 5 μm to 10 μm,
Among these two or more nonwoven fabric layers 12, 12..., The average diameter of the pores of one nonwoven fabric layer 12 positioned more inward of the filter body 1,
The difference from the average diameter of the pores of one nonwoven fabric layer 12 that is adjacent to this and located outside of this,
It is one of the options that brings about a good effect to be 40 μm or less.

  In this way, dust and the like in the fuel that has been filtered by the filter body 1 can be appropriately reduced due to the properties of dust etc. that are normally contained in the fuel, and clogging of the filter body 1 can be prevented for a long time. It was recognized that it was difficult to generate.

  FIG. 2 is a graph showing an example in which the filter body 1 is configured by providing three nonwoven fabric layers 12... 12 formed by a melt blown method.

  The horizontal axis in FIG. 2 is the diameter of the pores provided in the nonwoven fabric layer 12, and the vertical axis is the ratio of the area of pores having a specific diameter to the total pore area of one nonwoven fabric layer 12.

  In FIG. 2, the solid line represents the properties of the pores of the nonwoven fabric layer 12 located in the innermost part of the filter body 1, the broken line represents the properties of the pores of the nonwoven fabric layer 12 located in the middle, and the one-dot chain line represents the most It represents the properties of the pores of the nonwoven fabric layer 12 positioned outward.

  In this example, the average diameter of the pores of the nonwoven fabric layer 12 positioned in the innermost part of the filter body 1 is 7.1 μm, and the average diameter of the pores of the nonwoven fabric layer 12 positioned in the middle is 15.1 μm, The average diameter of the pores of the nonwoven fabric layer 12 located on the outermost side is 27.0 μm.

  The difference in the average diameter of the pores between the adjacent nonwoven fabric layers 12 and 12 is 40 μm or less, and the filtration gradient is gentle.

  Further, the outermost layer of the filter body 1 of the filter device F can be constituted by the woven mesh 13.

  In this case, the moisture contained in the fuel and the fuel can be separated by the outermost layer so that the moisture does not enter the filter body 1, and the nonwoven fabric layer 12 formed by the melt blown method is directly It is possible to prevent the fuel tank T from being worn in contact with the inner wall Ta or the like of the fuel tank T. That is, in the filter device F, the lower inner wall surface Ta of the fuel tank T moves in and out due to a change in the internal pressure of the fuel tank T (that is, the expansion and contraction of the fuel tank T, etc.). Even if rubbing occurs between the lower surface portion 12 of the filter body 1 and the lower inner wall surface Ta of the fuel tank T, the inner layer portion 13 made of a non-woven fabric is not directly affected by such rubbing. The nonwoven fabric constituting the inner layer portion 13 is not frayed.

  The woven mesh 13 constituting the outermost layer is typically formed by weaving synthetic fibers such as nylon fibers, polyethylene fibers, and polypropylene fibers so as to have a fine mesh sufficient for oil-water separation. The woven mesh 13 can be constituted by, for example, tatami mat, plain weave, twill weave, satin weave, or the like.

  Moreover, the innermost layer of the filter body 1 can be constituted by a nonwoven fabric layer 14 formed by a spunbond method.

  In this case, the innermost layer can impart rigidity (stiffness) to the filter body 1 so that the filter body 1 can be easily shaped. Further, the nonwoven fabric layer 14 formed by the spunbond method having higher rigidity can be brought into contact with the gap forming member 3 without contacting the nonwoven fabric layer 12 formed by the melt blown method.

  Moreover, each layer of the filter body 1 composed of multiple layers can be made of the same synthetic resin material. For example, each of these layers is made of polypropylene or nylon.

  In such a case, after the constituent materials of each layer having a sheet shape or a mat shape are laminated, they can be well integrated by welding to form a bag-like filter body 1.

  In the example shown in FIG. 3, the outermost layer of the filter body 1 is a woven mesh 13, the innermost layer is a nonwoven fabric layer 14 formed by a spunbond method, and a two-layer melt blown method is formed between them. The filter body 1 is configured so as to sandwich the nonwoven fabric layers 12 and 12 therebetween. Of the two nonwoven fabric layers 12 and 12, the average diameter of the pores of the nonwoven fabric layer 12 in contact with the innermost layer is smaller than the average diameter of the pores of the nonwoven fabric layer 12 in contact with the outermost layer.

  The filter body 1 can also be configured by providing three or more nonwoven fabric layers 12 formed by the melt blown method. In this case, the average diameter of the pores in the nonwoven fabric layer 12 positioned outward of the filter body 1 is such that the average diameter of the pores in the nonwoven fabric layer 12 positioned inward of the filter body 1 becomes small. To be larger.

  The filter body 1 according to the example shown in FIG. 1 overlaps a nonwoven fabric formed by a melt-blown method between a woven mesh and a nonwoven fabric formed by a spunbond method. The non-woven fabric formed by the bond method is positioned inward and folded in half with the gap forming member 3 sandwiched therebetween, and thereafter, over the side excluding the folded side, or By forming a heat seal portion 15 that integrates one side and the other side that are folded in two along the side portion excluding the folded side portion and inward from the side portion. Can be configured. Prior to performing the bi-folding, the communication hole 11 to the cylindrical socket body 2 is previously drilled in the four pieces of cloth overlapped as described above.

  Alternatively, the filter body 1 according to the illustrated example is formed by superposing two nonwoven fabrics formed by the melt blown method between the woven mesh and the nonwoven fabric formed by the spunbond method. And a second laminate in which two nonwoven fabrics formed by a melt blown method are sandwiched between a woven mesh and a nonwoven fabric formed by a spunbond method. The non-woven fabric formed by the spunbond method of the laminate and the non-woven fabric formed by the spunbond method of the second laminate face each other, and the gap forming member 3 is sandwiched therebetween. In this state, the first laminated body and the second laminated body are integrated so as to go around the outer periphery of the sandwiched gap forming member 3. By forming the pole tip 15 can be configured. The communication hole 11 to the cylindrical socket body 2 is previously drilled in the first laminated body or the second laminated body.

  The filter body 1 formed in this way may be appropriately subjected to spot welding so that the layers constituting the filter body 1 are integrated except for the heat seal portion 15 prior to the formation. .

  Further, unnecessary portions located outside the heat seal portion 15 are cut as necessary so as to adjust the shape of the filter body 1.

Cross-sectional configuration diagram showing the usage state of the filter device F The graph which showed an example of the combination of the nonwoven fabric layer 12 which comprises the filter body 1 Expanded cross-sectional configuration diagram showing a configuration example of the filter body 1

Explanation of symbols

F Filter device P Fuel inlet T Fuel tank 1 Filter body 12 Non-woven fabric layer

Claims (5)

A filter device having a bag-like filter body and attached so as to communicate the internal space of the filter body with a fuel suction port in the fuel tank,
This filter device has an interval forming member that is housed in the filter body and keeps the filter body in an inflated bag shape,
The filter body has two or more non-woven fabric layers formed by laminating a constituent material that forms a sheet shape or a mat shape,
The pores of one nonwoven fabric layer of the two or more nonwoven fabric layers are in the range of 1.7 μm or more and 16.6 μm or less,
The pores are made so that the average diameter of the pores of one nonwoven fabric layer positioned outside the nonwoven fabric layer having the pores in the range of 1.7 μm or more and 16.6 μm or less makes the filtration gradient gentle. It is larger than the average diameter of the pores of the nonwoven fabric layer in the range of 1.7 μm or more and 16.6 μm or less,
Moreover, the nonwoven fabric layer having pores in the range of 1.7 μm or more and 16.6 μm or less and the nonwoven fabric layer that is positioned outward and has a gentle filtration gradient are formed by the melt blown method.
Furthermore, the average diameter of the pores of the nonwoven fabric layer having the pores in the range of 1.7 μm or more and 16.6 μm or less, and the average diameter of the pores of the nonwoven fabric layer positioned more outward than this to moderate the filtration gradient The fuel filter device is characterized in that the difference between the two is 40 μm or less. A filter device having a bag-like filter body and attached so as to communicate the internal space of the filter body with a fuel suction port in the fuel tank,
This filter device has an interval forming member that is housed in the filter body and keeps the filter body in an inflated bag shape,
The filter body has two or more non-woven fabric layers formed by laminating a constituent material that forms a sheet shape or a mat shape,
One of the two or more nonwoven fabric layers is configured so that 50% of the total pore area of the nonwoven fabric layer is occupied by pores of about 10 μm or less,
This non-woven fabric has an average pore diameter of one non-woven fabric layer located outside the non-woven fabric layer that occupies 50% of the total pore area of this non-woven fabric layer with pores of about 10 μm or less so that the filtration gradient is moderated. It is larger than the average diameter of the pores of the nonwoven fabric layer, which occupies 50% of the total pore area of the layer by pores of about 10 μm or less,
Moreover, the nonwoven fabric layer that occupies 50% of the total pore area of the nonwoven fabric layer with pores of about 10 μm or less and the nonwoven fabric layer that is positioned outside this and has a gentle filtration gradient are formed by the melt blown method,
Furthermore, the average diameter of the pores of the nonwoven fabric layer that occupies 50% of the total pore area of the nonwoven fabric layer with pores of about 10 μm or less, and the average diameter of the pores of the nonwoven fabric layer that is located outside and makes the filtration gradient gentler The fuel filter device is characterized in that the difference between the two is 40 μm or less.   The fuel filter device according to claim 1 or 2, wherein the outermost layer of the filter body is a woven mesh.   4. The fuel filter device according to claim 1, wherein the innermost layer of the filter body is a non-woven fabric layer formed by a spunbond method. 5.   5. The fuel filter device according to claim 1, wherein each layer of the multilayer filter body is made of the same synthetic resin material. 6.

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