JP2009197686A - Fuel filter device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel filter device capable of reliably prolonging the filtering lifetime and having excellent durability accordingly. <P>SOLUTION: The fuel filter device 3 includes a filter element 31 provided between a fuel tank 2 and an engine 8 for collecting collection objects in fuel supplied to the engine 8, and filter casing 32 for storing the filter element 31 therein to trap an object to be trapped, and having an inlet part 33 and an outlet part 34 for guiding the fuel, and introduces the fuel from the inlet part 33 of the filter casing 32 and takes out the fuel with the collection object being removed by the filter element 31 from the outlet part 34. The fuel filter device further includes a resistance member 38 for applying the larger flow resistance to the fuel flowing in the filter element 31 as a part of application is closer to the inlet part 33 is provided between the inlet part 33 and the filter element 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel filtering device, and is suitably applied to a fuel filtering device that performs fuel filtering in a fuel supply device that supplies fuel to an internal combustion engine such as a diesel engine.

  Conventionally, as a fuel filtering device, for example, in a fuel supply device that supplies fuel to a diesel engine, a fuel filter that is provided between a fuel tank and an internal combustion engine and removes foreign matters such as dust and metal powder in the fuel is known. (Patent Document 1 etc.). This type of internal combustion engine has a component that slides in the fuel, such as a fuel injection valve that injects fuel into the internal combustion engine, and the fuel filtering device uses a filter medium having a relatively small fuel passage, It prevents minute foreign matter from entering these components.

In the apparatus disclosed in Patent Document 1 as one type of such a fuel filtration apparatus, the filtration area per unit volume is increased by forming the filter medium in a honeycomb shape. By expanding the filtration area of the filter medium, the life of the fuel filter can be improved.
JP-A-9-310648

  Now, in the prior art by patent document 1, it should be able to improve the filtration life of a fuel filter. However, as a result of intensive studies by the present inventors, it has been found that there is a concern that the filtration life may be reduced. The reason will be described below.

  In the apparatus disclosed in Patent Document 1, the filter medium accommodated in the housing of the fuel filter is formed in a complicated filter medium shape that increases the filtration area within the physique of the housing. Therefore, the flow of the fuel flowing between the peripheral wall on the fuel inflow side or the peripheral wall on the fuel outflow side of the filter medium and the inner wall of the housing tends to be an unstable flow (hereinafter, non-uniform flow).

  When such a non-uniform flow occurs, there is a possibility that a difference in the amount of collected foreign matter may occur for each partial region on the filter medium outer periphery side of the filter medium into which fuel flows. Therefore, there is a risk of causing a filtration life (hereinafter referred to as a partial filtration life) in the partial region. In this case, the filtration area of the filter medium actually used for fuel filtration is only a part of the total area, and therefore the effective filtration area is reduced and the filtration life is reduced, that is, the durability is reduced despite the increase in the filtration area. It will cause a decline in sex.

  The present invention has been made in consideration of such circumstances, and it is an object of the present invention to provide a fuel filtration device having excellent durability.

    In order to achieve the above object, the present invention comprises the following technical means.

That is, in the inventions according to claims 1 to 9, a filter element that is provided between the fuel tank and the internal combustion engine and collects a collection target in the fuel supplied to the internal combustion engine, and the filter element is housed inside. And a filter casing having an inlet portion and an outlet portion for introducing fuel, introducing fuel from the inlet portion of the filter casing, and deriving the fuel from which the collection target has been removed by the filter element from the outlet portion In
Between the inlet portion and the filter element, there is provided a resistance member that applies a greater flow resistance to the fuel flowing into the filter element at a portion closer to the inlet portion.

  In such an invention, a filter element that collects an object to be collected in the fuel is disposed in a filter casing having an inlet portion and an outlet portion that guide the fuel. The inflowing fuel flow may have a nonuniform fuel flow rate due to the fuel inflow portion of the filter element. Such a non-uniform flow rate has a large fuel flow rate in the filter surface portion of the filter element close to the inlet portion (hereinafter referred to as the upstream filter element portion), and a filter surface portion (hereinafter referred to as the portion of the filter element far from the inlet portion). In the downstream filter element portion), there is a concern that the fuel flow rate becomes small. Therefore, at least the upstream filter element portion and the downstream filter element portion have different amounts of fuel to be filtered, and there is a possibility that a difference occurs in the collection amount of each collection target.

  However, in addition to the above configuration, a configuration is provided in which “the portion closer to the inlet portion between the inlet portion and the filter element is provided with a resistance member that adds a large flow resistance to the fuel flowing into the filter element”. Therefore, according to the ease of flow in the fuel flow, a resistance member that forms a difficulty in flow opposite to this is arranged upstream of each filtration surface portion of the filter element. Thereby, the amount of fuel filtered by each filtration surface portion of the filter element becomes substantially the same, and as a result, the collection amount to be collected can be made substantially uniform at each filtration surface portion of the filter element.

  According to the first aspect of the present invention, the amount of fuel filtered at each filtration surface portion of the filter element can be made uniform and the entire filtration surface can be made an effective filtration surface. Improvement can be achieved reliably, and as a result, a fuel filtration device having excellent durability can be obtained.

  In the invention according to claim 2, the resistance member has a plurality of openings, and the openings are arranged on the upstream side of the fuel flow at a distance from the peripheral wall on the fuel inflow side of the filter element, and The opening area of the opening is enlarged along the flow of fuel from the inlet to the outlet.

  According to such a configuration, the resistance member is provided with a plurality of openings, and the opening area of the opening is enlarged along the flow of fuel from the inlet portion to the outlet portion in the filter casing. Even if the opening area of the opening portion is not formed so as to restrict the fuel flow, the opening is enlarged or reduced in accordance with the ease of flow in each filtering surface portion of the filter element. The resistance member can be obtained with a configuration of an opening formed in an area.

  In the fuel filtration device provided with such a resistance member, the filter element is adjusted by adjusting the opening area that forms the difficulty of flow according to the ease of flow while maintaining the nonuniform fuel flow velocity at each filtration surface portion. The amount of fuel that is filtered at each filtering surface portion can be made uniform.

  In addition, since the resistance member having the opening is arranged on the upstream side of the fuel flow with a gap from the peripheral wall on the fuel inflow side of the filter element, the region of the resistance member in which the opening is not formed (hereinafter referred to as the resistance member). The fuel that has passed through the opening of the resistance member wraps around downstream of the non-opening region. Even in the filtration surface portion corresponding to the downstream side of such a non-opening region, the fuel flows in substantially uniformly and is filtered by the opening portion surrounding the filtration surface portion.

  According to the second aspect of the present invention, it is possible to make uniform the amount of fuel filtered at each filtering surface portion of the filter element without correcting the non-uniform flow rate of fuel, and to perform total filtration. It can be ensured that the surface is an effective filtration surface.

  According to a third aspect of the present invention, the resistance member has a guide portion that restricts the flow of fuel, and the guide portion is spaced upstream from the peripheral wall on the fuel inflow side of the filter element and on the upstream side of the fuel flow. A bent portion is provided that restricts the fuel flow in the flow region on the peripheral wall side of the fuel flow that is disposed and flows from the inlet to the outlet.

  According to such a configuration, the resistance member is provided with the guide portion that restricts the flow of fuel, and the guide portion is a flow on the peripheral wall side of the fuel flow that flows along the outlet portion from the inlet portion in the filter casing. The resistance member can be obtained with a configuration in which a bent portion that restricts fuel flow is provided in the region.

  In the fuel filtration device provided with such a resistance member, the bending portion that directly forms the difficulty in flow according to the ease of flow is adjusted with respect to the state of uneven fuel flow velocity at each filtration surface portion. Thus, it is possible to reliably avoid the fuel from concentrating and flowing to a part of the filter element such as the upstream filter element portion, and to equalize the amount of fuel filtered by each filter surface portion of the filter element. It can be done.

  Moreover, since the resistance member having such a guide portion is disposed on the upstream side of the fuel flow with a gap from the peripheral wall on the fuel inflow side of the filter element, even if the bent portion is provided in the guide portion, for example. In the guide portion, the fuel goes around to the downstream side of the bent portion. In other words, even the filtration surface portion corresponding to the downstream side of the bent portion is substantially uniformly flowed and filtered by the fuel that is controlled so as to flow less easily by the bent portion.

  According to the third aspect of the invention described above, it is possible to make uniform the amount of fuel that is filtered at each filtration surface portion of the filter element, and to ensure that all the filtration surfaces are effective filtration surfaces.

  In the invention according to claim 4, the guide portion joins the fuel flow restricted in the flow region on the peripheral wall side by the bent portion to the fuel flow in the flow region on the opposite peripheral wall with the guide portion interposed therebetween, and It has the rectification | straightening part which rectifies | straightens the said combined fuel flow, It is characterized by the above-mentioned.

  In such an invention, the fuel flow state in the downstream filter element portion is less likely to flow than the fuel flow in the upstream filter element portion, but each bent portion provided in the guide portion of the resistance member allows Depending on the ease of flow in the filtration surface portion, the difficulty of flow is directly formed. For example, depending on the operating state of the internal combustion engine, the fuel flow state on the downstream filter element portion side should be relatively small. There is a concern that there will be only a small flow rate.

  On the other hand, according to the fourth aspect of the present invention, in addition to the above configuration of the guide portion, the guide portion causes the fuel flow restricted in the flow region on the peripheral wall side of the filter element in the fuel flow to the guide portion. And a rectification unit that rectifies the joined fuel flow in the flow region on the opposite circumferential wall side. The fuel flow rectified by the rectification unit is the fuel flow in the flow region on the anti-circumferential wall side combined with the fuel flow restricted in the flow region on the peripheral wall side. In addition to being formed into a main flow, the rectifying action can increase the momentum of the fuel flow in the flow region on the opposite circumferential wall side.

  Thereby, regardless of the operating state of the internal combustion engine, it is possible to make the amount of fuel filtered at each filtration surface portion of the filter element uniform, and to ensure that all the filtration surfaces are effective filtration surfaces.

  In the invention according to claim 5, the guide part is a part of the inner wall of the filter casing.

  According to this, the guide part is integrally formed with the inner wall of the filter casing that houses the filter element therein. Thereby, for example, a configuration of a guide portion having a bent portion that restricts the fuel flow and a rectifying portion that rectifies the fuel flow can be realized with a simple configuration without increasing the number of components.

  Further, in the invention according to claim 6, the filter element includes a filter medium that varies a thickness between the fuel inflow side and the fuel outflow side, and the filter medium is closer to the filter element at a portion closer to the inlet. It is characterized by a large thickness with respect to the inflowing fuel.

  For example, in order to improve the filtration performance (capability of collecting the collection target), it can be considered that the filter medium of the filter element is thickened. However, when the filter medium thickness is uniformly increased, there is a concern that the pressure loss increases excessively. In other words, depending on the part of the filter medium, there is a concern that the flow rate of the fuel after filtration, that is, the fuel flowing out to the downstream side of the filter medium, is almost insignificant.

  On the other hand, according to the invention described in claim 6, the thickness of the filter medium is variable between the side where the fuel flows in and the side where the fuel flows out, and the thickness is formed so that the portion closer to the inlet portion is thicker. Therefore, it can be reliably avoided that the fuel to be filtered concentrates and flows out to a part of the filter medium in the filter element such as the upstream filter element portion, and the amount of fuel to be filtered at each filter surface portion of the filter element is reduced. It can be made uniform.

  In the invention according to claim 7, a filter element that is provided between the fuel tank and the internal combustion engine and collects a collection target in the fuel supplied to the internal combustion engine, and the filter element is housed inside, In a fuel filtration device comprising a filter casing having an inlet portion and an outlet portion for introducing fuel, introducing fuel from the inlet portion of the filter casing, and leading out fuel collected by the filter element from the outlet portion, The filter element includes a filter medium that varies the thickness between the fuel inflow side and the fuel outflow side, and the filter medium is formed to have a greater thickness with respect to the fuel flowing into the filter element at a portion closer to the inlet. It is characterized by.

  According to such a configuration, for example, instead of the resistance member, a filter medium that varies the thickness between the fuel inflow side and the fuel outflow side is provided, and the thickness of the filter medium is thicker toward the part closer to the inlet (larger). ) Will be formed. Therefore, the fuel to be filtered can be reliably prevented from concentrating and flowing out to a part of the filter medium in the filter element such as the upstream filter element portion, and the amount of fuel filtered at each filter surface portion of the filter element can be reduced. It can be made uniform.

  Further, the invention according to claim 8 is characterized in that the filter element constitutes a filtering member that collects foreign substances or metal ions made of at least one of a metal and an organic substance as a collection target.

  According to such a configuration, for example, instead of the resistance member, a filter medium that varies the thickness between the fuel inflow side and the fuel outflow side is provided, and the thickness of the filter medium is thicker toward the part closer to the inlet (larger). ) Will be formed. Therefore, the fuel to be filtered can be reliably prevented from concentrating and flowing out to a part of the filter medium in the filter element such as the upstream filter element portion, and the amount of fuel filtered at each filter surface portion of the filter element can be reduced. It can be made uniform.

  Further, in the invention according to claim 9, the filter element constitutes an aggregating member that aggregates water particles in the fuel as a collection target and separates the aggregated water particles from the fuel. To do.

  According to this invention, for example, in a filter element including an aggregating member that separates water particles from fuel by aggregating water particles in the fuel and aggregating the water particles in the fuel, the water particles Although it is agglomerated in the process of passing, the water particles contained in the fuel can be uniformly condensed at each part of the agglomeration member, and as a result, the fuel has excellent durability without locally reducing the agglomeration efficiency. A filtration device can be obtained.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the component corresponding in each embodiment.

(First embodiment)
1 to 3 show a fuel filtering device according to the present embodiment. FIG. 1 shows the configuration of the fuel filtering device, and FIG. 2 shows the resistance member in FIG. FIG. 3 shows an example in which the fuel filtering device according to the present embodiment is applied to a pressure accumulation type fuel injection device of a diesel engine (hereinafter simply referred to as “engine”) as, for example, a “fuel injection device”.

  As shown in FIG. 3, the pressure accumulation type fuel injection device is a system that injects fuel into each cylinder (four cylinders in this embodiment) of the engine 8, and includes a fuel tank 2 and a feed pump as a “low pressure supply pump”. 42, the high pressure pump 43 as the “high pressure supply pump”, the common rail 5 and the fuel injection valve 6 and the like, and the driving state of the high pressure pump 43 and the fuel injection valve 6 are controlled so that Accordingly, a control circuit 90 is provided as a “control device” for controlling the discharge amount and the injection amount of the high-pressure fuel according to the above. As shown in FIG. 3, the feed pump 42 and the high-pressure pump 43 may be separate or integrally configured, and both the pumps 42 and 43 are referred to as the fuel injection pump 4. FIG. 3 shows only one cylinder of the engine 8 and the fuel injection valve 6 mounted thereon, and illustration of the fuel injection valves 6 corresponding to the other cylinders is omitted.

  In addition, the pressure accumulating fuel injection device, when expressed in the state of the fuel flowing between the components, is a high-pressure fuel system that supplies the engine 8 with fuel increased in pressure equivalent to the fuel injection pressure (hereinafter referred to as common rail pressure). The fuel tank 2 is combined with a low pressure fuel system that pumps up the fuel in the fuel tank 2 and pressurizes the fuel, and returns a part of the fuel supplied to the high pressure fuel system to the fuel tank 2 as surplus fuel. Hereinafter, the low-pressure fuel system is referred to as a fuel supply device 1.

(High pressure fuel system)
The high-pressure fuel system includes a high-pressure pump 43, a common rail 5, and a fuel injection valve 6 as main components. The high-pressure pump 43 is a fuel supply unit that pumps high-pressure fuel to the common rail 5, and forms high-pressure fuel by further compressing the low-pressure fuel discharged from the feed pump 42 in the pressurizing chamber 46. .

  The fuel whose pressure has been increased by the high-pressure pump 43 is supplied to the common rail 5 via the high-pressure fuel pipe 52 and stored. The high-pressure pump 43 is driven by the engine 8, and the discharge amount of the high-pressure fuel is larger than the injection amount, and the common rail 5 is filled in a short time by starting the engine.

  The common rail pressure of the fuel accumulated in the common rail 5 is detected by the pressure sensor 51, and the signal is sent to the control circuit 90. The high-pressure pump 43 further has a mechanism for electrically controlling the discharge amount. As the mechanism, the fuel flow is introduced into a fuel flow path that guides the fuel into the pressurizing chamber 46 that pressurizes the fuel to a high pressure. An intake metering valve 48 for adjusting the degree of opening of the road is attached. The suction metering valve 48 is controlled by a pump drive signal from the control circuit 90 to adjust the amount of fuel sucked into the pressurizing chamber 46 and discharge the fuel to be pumped to the common rail 5. Is changed. The control circuit 50 can control the common rail pressure to a pressure corresponding to the operating state of the engine (vehicle running state) by controlling the suction metering valve of the high-pressure pump 43.

  Further, the common rail 5 is provided with a pressure reducing valve (not shown) for releasing a part of the high-pressure fuel in the common rail 5, and the pressure reducing valve is controlled separately from the discharge amount adjustment by the intake metering valve 48. Drive control is performed by a signal from the circuit 90, and the common rail pressure can be adjusted to a predetermined pressure.

  The high-pressure fuel in the common rail 5 is distributed and supplied to the fuel injection valve 6 attached to each cylinder of the engine 8 via the high-pressure fuel pipe 53. The fuel injection valve 6 is driven and controlled by a drive circuit (not shown) in accordance with a signal from the control circuit 90, thereby adjusting the valve opening / closing timing for determining the fuel injection characteristics, and thus the operating state of the engine 8. Accordingly, the fuel injection adjusted to the optimal injection amount can be performed.

  Here, the discharge side of the high-pressure pump 43, the common rail 5, and the high-pressure fuel introduction side of the fuel injection valve 6 are always in communication with a high-pressure passage formed by high-pressure fuel pipes 52 and 53.

  The fuel injection valve 6 roughly includes a nozzle portion 60, a holder body 70, and an electromagnetic valve 79. The nozzle portion 60 has a nozzle body 61 having an injection hole 611 for injecting fuel, and an injection hole 611. It has a nozzle needle 69 that opens and closes. Further, the holder main body 70 is provided with a control piston 72 and a pressure control chamber 73, and the fuel pressure (back pressure) increased or decreased in the pressure control chamber 73 is set as a pressing force for driving the nozzle needle 69. The pressing force acts on the nozzle needle 69 via the control piston 72. The electromagnetic valve 79 increases or decreases the fuel pressure in the pressure control chamber 73 by opening and closing.

  In the nozzle portion 60, the nozzle needle 69 is accommodated in a nozzle body 61 so as to be movable in the axial direction, and the nozzle body 61 is formed in a substantially cylindrical body, and is on the tip end (lower end in FIG. 3) side. In addition, one or a plurality of nozzle holes 611 are provided. Further, the nozzle body 61 has a guide hole 62 and a valve in which a fuel reservoir chamber 67 and an abutting portion 69a of the nozzle needle 69 are seated and seated in the middle of the guide hole 62 toward the downstream of the fuel flow. A nozzle hole 611 penetrating the seat 66 and the inside and outside of the nozzle body 61 is provided. Furthermore, the nozzle body 61 is provided with a fuel delivery path 68 extending from the mating surface of the nozzle body 61 on the upper end side in the figure to the fuel reservoir chamber 67. The fuel delivery path 68 communicates with the fuel supply path 71 of the lower body 75, thereby feeding the high-pressure fuel accumulated in the common rail 5 to the valve seat 66 side via the fuel reservoir chamber 67. The fuel delivery path 68, the first fuel supply path 71, and the second fuel supply path 74 constitute a high-pressure fuel path. The second fuel supply path 74 is formed in the lower body 75 and is branched from the first fuel supply path 71, and supplies the high-pressure fuel to the pressure control chamber 73.

  The lower body 75 is formed in a substantially cylindrical body, and an accommodation hole 725 for accommodating the spring 76 and the control piston 72 so as to be movable in the axial direction is provided therein. A spring chamber forming hole 725b that is larger than the second guide hole 725a that allows the control piston 72 to slide is formed on the mating surface on the lower end side of the accommodation hole 725 in the figure. By sandwiching the spring 76 between the upper end surface of the spring chamber forming hole 725b and the spring receiving portion 72a, the spring 76 biases the nozzle needle 69 in the valve seat direction. The pressure control chamber 73 is partitioned by a guide hole 725 a and a control piston 72.

  A sliding gap between the control piston 72 and the second guide hole 725a (hereinafter referred to as a first sliding gap), and a sliding gap between the guide hole 62 of the nozzle body 61 and the nozzle needle 69 (hereinafter referred to as a second sliding gap). Gap) and a sliding gap (hereinafter referred to as a third sliding gap) between a plunger 45 and a cylinder (sliding hole) 44 in the fuel injection pump 4 described later constitute a high-pressure sliding gap through which high-pressure fuel is guided. Yes.

  The electromagnetic valve 79 includes a coil (not shown) that generates an electromagnetic force by supplying electric power from the outside, a movable core (not shown) that cooperates with the valve body, and magnetically attracts the valve body and the movable core by the action of the electromagnetic force. A solenoid valve having a well-known structure having a fixed core (not shown) that increases or decreases the fuel pressure (back pressure) in the pressure control chamber 73. Specifically, an orifice portion 755 is provided between the electromagnetic valve 79 and the control piston 72, and the pressure control chamber 73 is defined by the orifice portion 755, the control piston 72, and the second guide hole 725a. . A second valve seat (not shown) on which a valve body cooperating with the movable core is seated and separated is formed on the end surface of the orifice portion 755 on the movable core side.

  The high-pressure pump 43 includes a cam 41a, a plurality of (for example, three in this embodiment) plungers 45, a pressurizing chamber 46 disposed opposite to the plungers 45, and a suction metering valve 48, and a feed pump. The fuel supplied from 42 is supplied to the pressurizing chamber 46 through the intake metering valve 48 and supplied to the cam chamber 43c as a fuel for lubrication.

  The plungers 45 are arranged at equal intervals of 120 ° with the drive shaft 41 interposed therebetween. The plunger 45 can reciprocate in a sliding hole (also referred to as a cylinder) 44 of the housing 43a. One end surface (upper end surface in the drawing) of the plunger 45 is in contact with the pressurizing chamber 46 and the other end surface (in the drawing). Are in contact with the cam 41a via a transmission member such as a shoe (not shown), and reciprocate in the slide hole 44 by the rotation of the cam 41a. A discharge valve 49 is provided on the discharge side of the pressurizing chamber 46. The discharge valve 49 prevents backflow into the pressurizing chamber 46.

(Fuel supply device 1 (low pressure fuel system))
The fuel supply device 1 includes a fuel tank 2, a feed pump 42, a fuel filter 3 as a “fuel filter device”, and the like as main components.

  The fuel in the fuel tank 2 is pumped from the suction side of the feed pump 42 through the fuel filter 3. The feed pump 42 preliminarily pressurizes the fuel filtered by the fuel filter 3, whereby low pressure fuel (hereinafter referred to as “feed fuel”) preliminarily pressurized from the discharge side of the feed pump 42 is supplied to the high pressure pump 43. To supply.

  The feed pump 42 includes a pressure adjusting device (not shown) for adjusting a preliminary pressure (hereinafter referred to as “feed pressure”) of the feed fuel between the discharge side and the suction side. The pressure adjusting device adjusts the feed pressure to a predetermined set pressure by returning a part of the feed fuel discharged from the discharge side of the feed pump 42 to the high pressure pump 42 side to the suction side on the fuel tank 2 side. is there.

  Here, in the high-pressure pump 43, the common rail 5, and the fuel injection valve 6 which are also components of the high-pressure fuel system, a part of the fuel (feed fuel or high-pressure fuel) supplied to each component is used as surplus fuel. The fuel flows out to the surplus fuel passage such as the fuel recovery pipe 791 and returns to the fuel tank 2 through the surplus fuel passage. In FIG. 3, the fuel tank 2 is configured separately from the first fuel tank 2a and the second fuel tank 2b for the sake of convenience, but may be configured as a single fuel tank.

  Further, even if the high-pressure pump 43 is configured separately from the feed pump 42, the high-pressure pump 43 and the feed pump 42 are integrally assembled and, for example, the engine 8 is connected via the common pump drive shaft 41. It may be a so-called supply pump having a well-known structure driven by.

  The accumulator fuel injection device and the fuel supply device 1 have been described above. Hereinafter, the basic configuration of the fuel filter 3 will be described.

(Fuel filter 3)
The fuel filter 3 is demonstrated based on FIG.1 and FIG.2. As shown in FIG. 1, the fuel filter 3 includes a filter element 31 that filters fuel, and a filter casing 32 that houses and holds the filter element 31 therein. The upper side of FIG. 1 is the upper side in a state in which the fuel filter is attached to a mating attachment member (for example, a vehicle such as an automobile in this embodiment).

  The filter casing 32 includes an inlet portion 33 and an outlet portion 34 that guide fuel, and is formed in a cylindrical shape. The inner wall 32a of the filter casing 32 has a cylindrical filter element 31 disposed substantially concentrically therein. The inlet portion 33 and the outlet portion 34 are formed with fuel hole portions 33a and 34a penetrating the inner wall 32a of the cylindrical filter casing 32 in the vertical direction in the figure, and the inlet portion 33 has an outer periphery with respect to the outlet portion 34. Arranged on the side. The inlet portion 33 and the outlet portion 34 constitute a cylindrical wall portion that forms the fuel hole portions 33a and 34a in the inner wall.

  In such a filter casing 32, the outlet portion 34 is disposed substantially coaxially with the filter element 31, and holds the filter element 31 via a substantially disc-shaped support member 39. The support member 39 is provided with support portions 39a and 39b that support at least one of the shaft end portions of the cylindrical filter element 31, for example, between the support portion (hereinafter referred to as a lower support portion) 39a and the inner wall 32a. Are attached to a holding member (not shown) for connecting and holding the two.

  The filter element 31 is formed of a filter medium 31a that traps material particles in the fuel. The filter medium 31a is formed of a filter paper or a non-woven fabric, and a filter paper or a non-woven fabric having a pore diameter capable of capturing (collecting) substance particles is used. Further, the shape of the filter medium 31a may be any of a cylindrical shape, a spiral shape, or a chrysanthemum shape (in this embodiment, for example, a cylindrical shape).

  In the filter element 31 composed of such a filter medium 31a, as shown in FIG. 1, the fuel particles pass through the peripheral wall from the outer peripheral side to the inner peripheral side, whereby the substance particles are captured.

  When the fuel flows into the fuel filter 3 from the inlet 33, the fuel filter 3 flows in a downward direction in the drawing along the outer peripheral surface 31b as a “filtration surface” on the peripheral wall side of the filter element 31. The filter element 31 passes through the filter element 31a from the outside toward the inside. The fuel that has passed through the filter medium 31a flows in the upward direction in the drawing along the inner peripheral surface 31c of the peripheral wall, and flows out of the fuel filter 3 from the outlet portion 34.

  Here, as the internal fuel passage between the inlet portion 33 and the outlet portion 34, a cylindrical fuel passage portion (hereinafter referred to as a first fuel passage portion) 35 formed mainly between the inner wall 32a and the outer peripheral surface 31b, The second fuel passage portion 36 is formed inside the inner peripheral surface 31c. Further, the inlet portion 33 is offset from the outlet portion 34 to the outer peripheral portion side in the filter casing 32, and above the support portion (hereinafter referred to as the upper support portion) 39b as shown in FIG. 1 according to the offset amount. A substantially annular third fuel passage portion 37 is formed between the upper support portion 39b and the inner wall 32a.

  The first fuel passage portion 35 is branched into a fuel path through which a part of the fuel passes to the filter medium 31a as it goes downstream (downward in the drawing) along the outer peripheral surface 31b of the filter element 31. Since the total amount of fuel increases, there is a concern that the flow rate of the fuel is decelerated toward the downstream side in each part of the first fuel passage portion 35 and the size thereof is reduced.

  On the other hand, the third fuel passage portion 37 is a relay passage where the fuel is directed to the first fuel passage portion 35, and the flow rate of the fuel is substantially reduced by passing the fuel through the third fuel passage portion 37. There is no deceleration.

  The basic configuration of the fuel filter 3 has been described above. Hereinafter, a characteristic configuration of the fuel filter 3 will be described.

(Characteristic configuration)
As shown in FIGS. 1 and 2, in this embodiment, a resistance member 38 having a plurality of openings 381 is provided at a distance from the peripheral wall on the fuel inflow side of the filter element 31. In other words, in the first fuel passage portion 35, a plurality of openings 381 are formed by the resistance member 38 at a distance from the outer peripheral surface 31 b of the filter element 31.

  In addition, the opening area of the opening 381 varies along the flow from the inlet 33 to the outlet 34, that is, along the first fuel passage 35, and the area of the opening 381 is enlarged. It is configured to be.

  Moreover, in this embodiment, the said resistance member 38 is provided in the outer peripheral part of the 2nd support part 39b, and is formed integrally. The resistance member 38 and the second support portion 39b are formed in a bottomed cylindrical body that opens downward in the drawing.

  Here, the filter medium 31a of the filter element 31 corresponds to the filtering member described in the claims. The substance particles in the fuel captured by the filter medium 31a correspond to the collection target described in the claims. The target to be collected by the filter medium 31a in this embodiment is a foreign substance (substance particle) made of at least one of a metal and an organic substance contained in the fuel.

  The fuel filter 3 having the above configuration can obtain the following characteristic operations and actions.

(Characteristic operation and action)
When driving force is obtained from the crankshaft or the like of the engine 8 and the pump drive shaft 41 is rotationally driven, the cam 41a rotates, and each plunger 45 reciprocates in the slide hole 44 by the rotation of the cam 41a. When the plunger 45 moves downward in the drawing of FIG. 3 along with the rotation of the cam 41a, the fuel pressure in the pressurizing chamber 46 decreases, and the fuel regulated by the suction metering valve 48 is added due to this fuel pressure drop. It is sucked into the pressure chamber 46.

  At this time, the feed pump 42 is driven to rotate along with the rotation of the pump drive shaft 41, whereby the fuel stored in the fuel tank 2 is pumped up and flows into the fuel filter 3. Then, the pumped fuel flows from the inlet 33 into the cylindrical space in the filter casing 32. When the fuel flowing in from the inlet 33 passes through the filter element 31 disposed in the filter casing 32, the foreign matter contained in the fuel is captured by the filter medium 31a, and the fuel from which the foreign matter has been removed becomes the fuel of the fuel filter 3. Outflow from the outlet 34 to the downstream side.

  The fuel flowing out from the outlet 34 of the fuel filter 3 is sucked from the suction side of the feed pump 42 and pre-pressurized, and is adjusted to a predetermined feed pressure by the pressure adjusting device, and from the discharge side of the feed pump 42. It is discharged toward the pressurizing chamber 46.

  On the other hand, when the plunger 45 moves upward in the drawing of FIG. 3 with the rotation of the cam 41a, the fuel filled in the pressurizing chamber 46 is pressurized to increase the pressure of the fuel to the common rail pressure.

  Now, in the fuel filter 903 of the comparative example to which the conventional technique as shown in FIG. 18 is applied, a part of the fuel is moved toward the downstream side (downward in the drawing) along the outer peripheral surface 931b of the filter element 931. Since the total amount of the branched fuel increases by branching to the fuel path passing to the filter medium 931a, the flow velocity of the fuel is decelerated toward the downstream side in each portion of the first fuel passage portion 935, and the size is surely reduced. To go. In FIG. 18, the magnitude of the fuel flow rate is represented by the thickness of the arrow line, and the thicker the arrow line, the greater the flow rate.

  In other words, in the comparative example of FIG. 18, the flow velocity of the fuel decreases from the inlet portion 33 along the first fuel passage portion 935, and the fuel does not flow easily.

  On the other hand, in this embodiment, the fuel that has flowed into the filter casing 32 from the inlet 33 flows into the second fuel passage portion 35 in the cylindrical space. A plurality of openings 381 are formed by the resistance member 38 at intervals from the outer peripheral surface 31 b of the filter element 31. Moreover, the opening 381 is configured such that the opening area between the openings 381 is enlarged from the inlet 33 to the second fuel passage 35. That is, the fuel hardly flows along the first fuel passage portion from the inlet portion 33 as in the comparative example of FIG. 18, whereas the opening portion 381 having an enlarged opening area is disposed at a portion away from the inlet portion 33. To do.

  In other words, by arranging the opening 381 having a reduced opening area at a portion closer to the inlet portion 33, the opening opposite to this state corresponds to a state in which the fuel is more likely to flow toward the portion closer to the inlet portion 33. The opening characteristic of the portion 381, that is, the reduced opening area that suppresses the amount of fuel passing through the opening 381 is set.

  In the fuel filter 3 including the resistance member 38 having the opening 381 having such a configuration, the fuel flow state around the peripheral wall on the fuel inflow side of the filter element 31, that is, the portion closer to the inlet portion 33 in the first fuel passage portion 35. Corresponding to the state in which the fuel is easy to flow, the opening 38 having the opening characteristic opposite to this state is disposed, so that the amount of fuel flowing through the opening 381 to the outer peripheral surface 31b of the filter element 31 is reduced to the first fuel passage portion 35. It can be made uniform in the filtration surface portion of any outer peripheral surface 31b of the filter element 31 corresponding to.

  In addition, the resistance member 38 having the opening 381 is disposed on the upstream side of the fuel flow at a distance from the peripheral wall 31b on the fuel inflow side of the filter element 31, that is, the outer peripheral surface 31b. The fuel that has passed through the opening 381 of the resistance member 38 wraps around the region where the opening 381 is not formed (hereinafter referred to as a non-opening region). Even in a portion of the outer peripheral surface 31b corresponding to the downstream side of such a non-opening region (hereinafter referred to as a filtering surface portion corresponding to the non-opening region), the fuel is supplied by the opening 381 surrounding the filtering surface portion. It flows almost uniformly and is filtered.

  Further, in the fuel filter 3 including the resistance member 38 having the opening 381 having the above-described configuration, each filter element 31 can be filtered even if the opening area of the opening 381 is not formed so as to restrict the fuel flow. Depending on the ease of flow in the surface portion, the opening 381 having an enlarged or reduced opening characteristic contrary to this can be formed. Therefore, the opening 381 is adjusted to an opening area that forms a difficulty in flow according to the ease of flow due to such fuel flow speed while allowing uneven fuel flow speed at each filtration surface portion of the filter element 31. Thus, the amount of fuel filtered at each filtering surface portion of the filter element 31 can be made uniform.

  Here, the resistance member 38 restricts the fuel flow in the non-opening region. Then, the resistance member 38 adjusts the opening 381 to the size of the opening having an enlarged or reduced opening characteristic contrary to this according to the ease of flow in each filtering surface portion of the filter element 31. is doing. The resistance member 38 having such a configuration corresponds to a state in which the fuel is more likely to flow toward the portion closer to the inlet 33, and applies a large resistance to the opening characteristic contrary to this state, that is, the fuel flowing into the filter element 31. It has components.

(Second Embodiment)
A second embodiment is shown in FIG. 2nd Embodiment shows an example which provided the guide part 138a which has the bending part 138b which forms the difficulty of a flow directly according to the ease of the flow in each filtration surface part of the filter element 31 as the resistance member 138. Is. 4 and 5 show the fuel filter 3 according to the second embodiment, and FIG. 5 shows the periphery of the resistance member 138 in FIG.

  As shown in FIGS. 4 and 5, the resistance member 138 is formed in a bottomed cylindrical body that opens downward in the figure, and accommodates the upstream end of the filter element 31 inside the lower opening 138d. Yes. The resistance member 138 has a guide portion 138 a extending along the first fuel passage portion 35. The guide portion 138a is provided at a radial interval from the outer peripheral surface 31b of the filter element 31, and the guide portion 138a has a first fuel passage portion 35 on the distal end side (lower end portion side in the drawing). A bent portion 138b that restricts the fuel flow is provided in the flow region on the outer peripheral surface 31b side of the fuel flow. That is, the bent portion 138 b extends in a bell mouth shape toward the inner wall 32 a side of the filter casing 32 at the distal end portion of the guide portion 138 a.

  The operation and action of the fuel filter 3 having the above configuration will be described. In the enlarged view showing the local fuel flow in FIG. 5, the magnitude of the fuel flow velocity is represented by the thickness of the arrow line, and the thicker the arrow line is, the larger the flow velocity is. In addition, also in the figure which shows the main fuel flows of FIG. 4, it represents with the thickness of an arrow line, and shows that the flow velocity is so large that an arrow line becomes thick.

  As shown in FIG. 5, in the first fuel passage portion 35, the bent portion 138b restricts the fuel flow so that the fuel flow direction (the fuel flow flowing downward in the drawing) of the first fuel passage portion 35 is directed to the outer peripheral side. To do. On the downstream side of the fuel flow restricted by the bent portion 138b, a vortex (flow indicated by an example of an arrow line indicated by a broken line) is generated at the position over the bent portion 138b, and as a result, the downstream immediately after the bent portion 138b. The fuel flow flowing into the upstream end of the filter element 31 is weakened by the generation of vortex flow, and the flow velocity is reduced. In other words, the fuel flow is decelerated in the flow region on the outer peripheral surface 31 b side in the fuel flow of the first fuel passage portion 35.

  Here, the bent portion 138b constitutes a protruding portion that inhibits the flow of fuel inward at the distal end portion of the guide portion 138a.

  On the other hand, in the flow region on the inner wall 32a side in the fuel flow of the first fuel passage portion 35, the fuel flow is not directly restricted by the bent portion 138b. Moreover, since the bent portion 138b protrudes toward the inner wall 32a, the flow passage cross-sectional area of the first fuel passage portion 35 is gradually reduced at the bent portion 138b, so that the flow velocity is increased.

  As a result, in the case of the comparative example of FIG. 18, it becomes difficult for the fuel to flow along the first fuel passage portion from the inlet portion 33, and as a result, there is almost no flow rate on the downstream side of the first fuel passage portion. Although there is concern, in this embodiment, the flow rate of the fuel which goes to the downstream of the 1st fuel passage part can be raised. Therefore, in the present embodiment, it can be avoided that almost a small flow velocity exists on the downstream side of the first fuel passage portion.

  In the present embodiment described above, the bent portion 138b that directly forms the difficulty in the flow according to the ease of flow is adjusted with respect to the state of uneven fuel flow velocity at each filtration surface portion of the filter element 31. Thus, it is possible to reliably avoid that the fuel concentrates on a part of the filter element such as the upstream part (upstream filter element part) of the filter element 31 and is filtered by each filter surface part of the filter element. This makes it possible to make the fuel amount uniform.

  Moreover, the resistance member 138 having such a guide portion 138a is disposed on the upstream side of the fuel flow at a distance from the outer peripheral surface 31b of the filter element 31 in the radial direction. Even if the bent portion 138b is provided, the fuel flows around the downstream side of the bent portion 138b to form an inward flow. In other words, even the filtration surface portion corresponding to the downstream side of the bent portion 138b is almost uniformly introduced and filtered by the fuel controlled to flow difficult to flow by the bent portion 138b.

  Even with the above configuration, as in the first embodiment, it is possible to make the amount of fuel filtered at each filtration surface portion of the filter element 31 uniform, and to ensure that all the filtration surfaces are effective filtration surfaces. .

(Third embodiment)
A third embodiment is shown in FIG. The third embodiment is a modification of the second embodiment. 3rd Embodiment shows an example which provided the guide part 138a which has the bending part 138b and the rectification | straightening part 138c as the resistance member 138. As shown in FIG. 6 and 7 show the fuel filter 3 according to the third embodiment, and FIG. 7 shows the periphery of the resistance member 138 in FIG.

  As shown in FIGS. 6 and 7, the resistance member 138 includes a bent portion 138 b and a rectifying portion 138 c provided on the downstream side of the bent portion 138 b.

  The rectifying unit 138c has a cylindrical shape and extends along the inner wall 32a, and is arranged substantially coaxially with the inner wall 32a. Such a rectifying unit 138c allows the fuel flow restricted by the guide portion 138a and the bent portion 138b in the flow region on the outer peripheral surface 31b side of the first fuel passage portion 35 to flow out of the first fuel passage portion 35. Is joined to the fuel flow in the flow region on the inner wall 32a side, and the joined fuel flow is rectified.

  Now, in the case of the comparative example of FIG. 18, it becomes difficult for the fuel to flow from the inlet portion 33 along the first fuel passage portion, so the fuel flow state in the downstream portion (downstream filter element portion) of the filter element 31. However, it becomes difficult to flow compared to the fuel flow in the upstream portion (upstream filter element portion) of the filter element 31. By providing the bent portion 138b with respect to the first fuel passage portion 35 in such a fuel flow state, difficulty in flowing is directly formed according to the ease of flow at each filtration surface portion. Depending on the operation state of 8, the fuel flow state in the downstream portion of the filter element 31 may possibly have a relatively small flow rate.

  On the other hand, in this embodiment, in addition to the bent portion 138b, the fuel flow limited by the bent portion 138 is merged with the fuel flow in the flow region on the inner wall 32a side, and the merged fuel flow is rectified. The rectifying unit 138c is included. The fuel flow rectified by such a rectifying unit is such that the restricted fuel flow merges with the fuel flow in the flow region on the inner wall 32a side, so the fuel flow in the flow region on the inner wall 32a side is In addition to being formed as a main flow, the rectifying action can increase the momentum of the fuel flow in the flow region on the inner wall 32a side.

  Thereby, regardless of the operating state of the engine 8, the amount of fuel that is filtered at each filtering surface portion of the filter element 31 can be made uniform, and the entire filtering surface can be reliably made an effective filtering surface.

(Fourth embodiment)
A fourth embodiment is shown in FIG. The fourth embodiment is a modification of the second embodiment. 4th Embodiment shows an example which provided the bending part function which restrict | limits a fuel flow in the flow area by the side of the outer peripheral surface 31b of the 1st fuel passage part 35 as the resistance member in the inner wall 32a of the filter casing 32. Is.

  As shown in FIGS. 8 and 9, the inner wall 32 a is provided with a stepped portion 321 in the upstream portion of the filter element 31 where the flow cross-sectional area of the first fuel passage portion 35 gradually increases. The step portion 321 has an inner peripheral shape corresponding to the function of the bent portion on the inner wall 32a.

  The stepped portion 321 has an enlarged diameter portion 322 and a rectifying portion 323. The enlarged diameter portion 322 is an outer peripheral surface along the upstream side portion of the filter element 31 from the upstream side immediately before the upper support portion 39b. The inner wall 32a is formed so as to expand its inner diameter in a direction away from 31b.

  The rectifying unit 323 is formed so as to be connected to the downstream end of the enlarged diameter portion 322. The inner periphery of the rectifying unit 323 has a cylindrical shape, extends along the outer peripheral surface 31b, and is arranged substantially coaxially with the outer peripheral surface 31b.

  Such a configuration of the stepped portion 321 having the enlarged diameter portion 322 and the rectifying portion 323 has the following effects. First, in the enlarged diameter portion 322, the flow passage cross-sectional area of the first fuel passage portion 35 is gradually enlarged, so that the flow velocity is easily reduced. In particular, the fuel flow in the flow region on the outer peripheral surface 31b side of the first fuel passage portion 35 is from the inner periphery of the enlarged diameter portion 322 compared to the flow on the outer side, that is, the fuel flow in the flow region on the inner wall 32a side. Since they are separated from each other, they are easily peeled off. As a result, the flow rate is easily reduced by the peeling.

  On the other hand, the fuel flow in the flow region on the inner wall 32a side has a concern that the flow velocity is easily reduced by the enlarged diameter portion 322, but the inner circumference of the rectifying portion 323 causes an unstable flow state such as separation. A stable flow state is maintained while avoiding this. In other words, the energy loss of the fuel flow in the flow region on the inner wall 32a side is effectively suppressed.

  As a result, the fuel flow in the first fuel passage portion 35 weakens the fuel flow in the flow region on the outer peripheral surface 31b side of the first fuel passage portion 35 as shown in FIG. While suppressing the amount of fuel diverted to the outer peripheral surface 31b of the portion, the fuel flow in the flow region on the inner wall 32a side opposite to this can be strengthened.

  Even with such a configuration, the same effect as in the second embodiment can be obtained.

  In addition, the stepped portion 321 having the above-described configuration, that is, the stepped portion 321 having an inner peripheral shape corresponding to the bent portion function is formed integrally with the inner wall 32 a of the filter casing 32. Therefore, for example, a configuration having a bent portion function for restricting the fuel flow and a rectifying portion function for rectifying the fuel flow can be realized with a simple configuration without increasing the number of components.

(Fifth embodiment)
A fifth embodiment is shown in FIG. The fifth embodiment is not a function of equalizing the amount of fuel flowing into each part of the outer peripheral surface, which is the filtering surface of the filter element, as a resistance member, but equalizing the amount of fuel that is filtered and flows out in the filter element This is an example in which the filter element 131 is provided with the function of 10 and 11 show the fuel filter 3 according to the fifth embodiment. FIG. 11 shows the thickness of the filter medium 131a of the filter element 131 in FIG. 10, and FIG. FIG. 11B shows the downstream portion of the filter element 131.

As shown in FIGS. 10 and 11, in the filter element 131, the filter medium 131a has a chrysanthemum shape. For example, a filter paper formed in a long band shape is arranged in the thickness direction of the filter paper (the radial direction in the drawing). The ridges and valleys are alternately formed, and the bent portions where the ridges and valleys are alternately formed are repeatedly formed in the longitudinal direction of the filter paper, thereby forming an annular shape.

  As shown in FIG. 11, the thickness of the filter medium 131a is variably formed, and the thickness of the filter element 131a is smaller than the thickness of the downstream portion of the filter element 131 shown in FIG. 11 (b). 131 is configured to have a thicker upstream portion. In other words, the thickness is formed so as to be thicker as the portion is closer to the inlet portion 33.

  Now, for example, in order to improve the filtration performance of the filter element (capability of collecting the collection target), it is conceivable to increase the thickness of the filter medium 931a of the filter element 931 as in the comparative example of FIG. However, when the filter medium thickness is uniformly increased, there is a concern that the pressure loss increases excessively. In other words, depending on the portion of the filter medium 931a, there is a concern that the flow rate of the filtered fuel, that is, the fuel flowing out downstream of the filter medium 931a, is almost insignificant.

  On the other hand, in the present embodiment, the filter medium 131a is configured such that the thickness between the fuel inflow side and the fuel outflow side is variable, and the thickness is formed so that the portion closer to the inlet portion is thicker. For example, it is possible to reliably avoid the concentrated fuel from flowing out to a part of the filter medium 131a in the filter element 131 such as the upstream portion of the filter element 131, and as a result, the amount of fuel that is filtered at each filtering surface portion of the filter element 131 Can be made uniform.

  Therefore, even with the above configuration, substantially the same effect as in the first embodiment can be obtained.

  In addition, the filter element 131 having the above-described configuration, that is, the filter element 131 having the filter medium 131a having the thickness characteristic of “homogenizing the amount of fuel to be filtered at each filtration surface portion of the filter element 131” is first to first. There is no special provision of resistance members as described in the third embodiment to increase the number of components. Therefore, with a simple structure, the filtration life can be reliably improved, and as a result, the fuel filter 3 having excellent durability can be obtained.

(Sixth embodiment)
A sixth embodiment is shown in FIG. The sixth embodiment is a modification of the first embodiment. The sixth embodiment shows an example in which the resistance member 238 is applied to a filter element 231 in which the shape of the filter medium 231a is configured as a honeycomb type. 12 and 13 show the fuel filter 3 according to the sixth embodiment, and FIG. 13 shows the resistance member 238 in FIG.

  As shown in FIG. 12, the filter element 231 has a filter medium 231a formed in a honeycomb shape. For example, the filter element 231 is formed by laminating two filter papers formed in a long band shape and wound in the longitudinal direction. It is formed in a cylindrical shape. The cylindrical filter element 231 is formed with a partition wall having a plurality of cells penetrating in the axial direction (not shown), and a blocking member that blocks a cell end portion of some of the plurality of cells. Is provided. Details of the honeycomb structure of the filter element 231 will be described later with reference to FIG. 16 of the seventh embodiment, which is a modification of the sixth embodiment.

  In the filter element 231 having such a configuration, as shown in FIG. 12, the fuel inflow side and the fuel outflow side are formed in the axial direction across both axial ends of the filter element 231. For such a fuel flow, the inlet 33 and the outlet 34 are provided at both shaft ends of the filter casing 32, respectively. The inner wall 32a of the filter casing 32 and the outer peripheral surface 231b of the filter element 231 are in substantially airtight contact, whereas the circular wall between the inner wall 32a of the filter casing 32 and the axial end surface 231c of the filter element 231 is respectively provided. A plate-shaped space is formed, and the disk-shaped space on the inlet portion 33 side of the disk-shaped space corresponds to the first fuel passage portion 235, and the disk-shaped space on the outlet portion 34 side is the second space. It corresponds to the fuel passage part 236.

  In the present embodiment, the resistance member 238 is formed in a disk shape, and is disposed upstream from the axial end surface 231c of the filter element 231 in the first fuel passage portion 235 with an axial interval. The resistance member 238 has a plurality of openings 381 penetrating in the axial direction, and is configured to have an opening characteristic such that the opening area of the opening 381 is reduced toward a portion closer to the entrance 33.

  Even with the fuel filter 3 having the above configuration, the same effects as those of the first embodiment can be obtained.

  The inlet 33 and the outlet 34 are preferably arranged coaxially with respect to the central axis of the filter casing 32. As a result, the flow rate of fuel in the first fuel passage portion 235 is concentrically with the central axis, and the flow velocity increases toward the inner peripheral side and decreases toward the outer peripheral side. Therefore, the opening characteristics of the opening 381 arranged in the resistance member 238 can be arranged point-symmetrically with respect to the central axis. As a result, for example, during assembly work for assembling the resistance member 238 into the fuel filter 3, there is no need for positioning in the circumferential direction, so that the fuel filter 3 having excellent productivity can be obtained.

(Seventh embodiment)
A seventh embodiment is shown in FIG. The seventh embodiment is a modification of the first embodiment. The seventh embodiment shows another example in which the resistance member 238 is applied to a filter element 231 in which the shape of the filter medium 231a is configured in a honeycomb shape. 14 to 16 show the fuel filter 3 according to the seventh embodiment, FIG. 15 shows a resistance member 238 in FIG. 14, and FIG. 16 shows a honeycomb structure of the filter element 231 in FIG. 16 (a) and 16 (b) are a perspective view and a cross-sectional view for explaining the fuel flow in the honeycomb structure.

  As shown in FIG. 14, the filter element 231 having a honeycomb structure is disposed in the filter casing 32, and the inlet portion 33 and the outlet portion 34 are attached to one shaft end portion of the filter element 231. The inlet 33 passes through the filter element 231 and communicates with a first fuel passage 235 that is a disk-like space on the opposite side across the filter element 231. The outlet portion 34 is arranged offset to the outer peripheral side with respect to the inlet portion 33 at the one shaft end portion.

  Even if it is such a structure, the same effect as 1st Embodiment and 6th Embodiment can be acquired.

  Here, the details of the honeycomb structure of the filter element 231 will be described based on FIGS.

  As shown in FIGS. 14 and 16, the filter element 231 has a filter medium 231a formed in a honeycomb shape. For example, the filter element 231 is formed by laminating two filter papers 231aa and 231ab formed in a long band shape, and has a longitudinal direction. It is wound in the direction and formed into a cylindrical shape.

  As shown in part of the cylindrical filter element 231 in FIG. 16A, the filter element 231 is formed with a partition wall 245 having a plurality of cells 241d and 241u penetrating in the axial direction. In some of the cells 240d and 240u among the plurality of cells 241d and 241u, a closing member 243 that closes the cell end portion is provided. In the filter element 231 having such a honeycomb structure, the filtration area can be effectively expanded by using the partition walls 245 that partition the cells 241d and 241u.

  As shown in FIG. 16B, the fuel travels from one shaft end portion (hereinafter referred to as an inflow side shaft end portion) of the filter element 231 to the other shaft end portion (hereinafter referred to as an outflow side shaft end portion). Flowing. In that case, fuel flows in from the cell 241d which opens among the cells on the inflow side shaft end side. The inflowing fuel passes through the partition wall 245 so that the fuel is filtered, and the fuel flows out from the cell 241u that opens on the outflow side shaft end side.

  On the other hand, in the closed cell 240d and the cell 240u on the inflow side shaft end side, the inflow and outflow of fuel are prevented, respectively.

  The closing member 243 uses a filler, and the cell end is closed by the filler. Further, the two filter papers 231aa and 231ab are both formed to have a uniform thickness. The partition wall 245 is configured by one of the filter paper 231aa and the filter paper 231ab. In the partition wall 245 shown in FIG. 16B, it is omitted whether it is the filter paper 231aa or the filter paper 231ab.

(Eighth embodiment)
An eighth embodiment is shown in FIG. The eighth embodiment is a modification of the seventh embodiment.

  As shown in FIG. 17, the partition wall 245 has a configuration in which the thickness between the fuel inflow side and the fuel outflow side is varied, and the thickness is formed so as to be closer to the opening portion of the inlet portion 33.

  Here, in the cell 241d on the inflow side shaft end side of the filter element 231, there is a concern that the flow rate of the inflow fuel becomes smaller toward the downstream side in the axial direction inside the cell along the partition wall 245. In other words, the closer to the opening of the inlet portion 33, the larger the flow velocity, and the farther from the opening of the inlet portion 33, the smaller the flow velocity.

  On the other hand, in the present embodiment, the partition wall 245 varies the thickness between the fuel inflow side and the fuel outflow side, and the thickness is formed so that the portion closer to the opening of the inlet portion 33 is thicker. For example, it is possible to reliably avoid the concentrated fuel from flowing out to a part of the filter medium 231a in the filter element 231 such as the end portion side of the cell 241d of the filter element 231, and as a result, filtration is performed at each filtration surface portion of the filter element 231. The amount of fuel to be used can be made uniform.

(Other embodiments)
Although a plurality of embodiments of the present invention have been described above, the present invention is not construed as being limited to these embodiments, and can be applied to various embodiments without departing from the scope of the present invention. .

  (1) In the present embodiment described above, for example, in the first to fifth embodiments, the shape of the filter media 31a and 131a of the filter elements 31 and 131 is a cylindrical shape or chrysanthemum shape. The sixth and seventh embodiments are not limited to the honeycomb type.

  (2) In the present embodiment described above, the fuel flows into the inner wall 32a of the filter casing 32 in the vertical direction as the arrangement position of the inlet 33 and the outlet 34 of the fuel filter 3 in the first to fifth embodiments. However, the present invention is not limited to this. For example, a configuration in which fuel flows in and out in the horizontal direction (lateral direction in the drawing) as in the sixth embodiment may be used. The direction in which the fuel flows in and out may be any.

  (3) Further, in the fuel path in which the fuel flows in and out of the fuel filter 3, the fuel is filtered by mainly flowing in the radial direction of the filter elements 31, 131 as in the first to fifth embodiments. The filter element 231 may be filtered mainly through the axial direction of the filter element 231 as in the sixth to eighth embodiments, and any fuel path in the fuel filter 3 may be used. Also good.

  (4) In the present embodiment described above, the collection target of the filter elements 31, 131, 231 by the filter media 31a, 131a, 231a is a foreign substance (substance particle) made of at least one of a metal and an organic substance contained in the fuel. However, the present invention is not limited to this, and metal ions eluted into the fuel may be used. The filter medium may be any filter medium such as filter paper, non-woven fabric, or ion exchange resin as long as it is a filter member that collects substance particles or metal ions.

  (5) In the present embodiment described above, the filter media 31a, 131a, and 231a have a capturing function of capturing material particles or metal ions with the filter media. These fine water particles may have a function of aggregating into a large water particle group or large water particles.

  (6) The material of the filter medium having the aggregating function may be a material different from the material of the trapping function, that is, the filter member, or the same material may be used.

1 is a schematic cross-sectional view showing a fuel filtration device according to a first embodiment of the present invention. It is an expanded view which shows the resistance member in FIG. It is a typical block diagram which shows the fuel supply apparatus to which the fuel filtration apparatus of 1st Embodiment of this invention is applied. It is typical sectional drawing which shows the fuel filtration apparatus of 2nd Embodiment. It is sectional drawing which shows the circumference | surroundings of the resistance member in FIG. It is typical sectional drawing which shows the fuel filtration apparatus of 3rd Embodiment. It is sectional drawing which shows the surroundings of the resistance member in FIG. It is typical sectional drawing which shows the fuel filtration apparatus of 4th Embodiment. It is sectional drawing which shows the surroundings of the resistance member in FIG. It is typical sectional drawing which shows the fuel filtration apparatus of 5th Embodiment. FIG. 11A is a cross-sectional view taken along line AA in FIG. 10 and FIG. 11B is a cross-sectional view taken along line BB in FIG. 10. It is typical sectional drawing which shows the fuel filtration apparatus of 6th Embodiment. It is the top view which looked at the resistance member in FIG. 12 from the XIII direction. It is typical sectional drawing which shows the fuel filtration apparatus of 7th Embodiment. It is the top view which looked at the resistance member in FIG. 14 from the XV direction. FIGS. 14A and 14B are diagrams showing a part of the filter element in FIG. 14, in which FIG. 14A is a perspective view, and FIG. It is sectional drawing explaining the characteristic part of the filter element concerning the fuel filtration apparatus of 8th Embodiment. It is typical sectional drawing which shows the fuel filtration apparatus of a comparative example.

Explanation of symbols

1 Fuel supply system (low pressure fuel system)
2 Fuel tank 3 Fuel filter (fuel filter)
31 Filter element 31a Filter medium 31b Outer peripheral surface (filter surface)
31c Inner peripheral surface 32 Filter casing 32a Inner wall 33 Inlet portion 33a Fuel hole portion 34 Outlet portion 34a Fuel hole portion 35 First fuel passage portion 36 Second fuel passage portion 37 Third fuel passage portion 38 Resistance member 381 Opening portion 39 Support member 39a, 39b Support section 4 Fuel injection pump 42 Feed pump (low pressure supply pump)
43 High-pressure pump (high-pressure supply pump)
44 Cylinder (sliding hole)
45 Plunger 5 Common rail 6 Fuel injection valve 60 Nozzle part 79 Solenoid valve 8 Engine 90 Control circuit (control device)

Claims (9)

A filter element provided between the fuel tank and the internal combustion engine, for collecting a collection target in the fuel supplied to the internal combustion engine; and an inlet portion and an outlet portion for accommodating the filter element therein and guiding the fuel A fuel filtration device that introduces fuel from the inlet portion of the filter casing, and derives the fuel from which the collection target has been removed by the filter element from the outlet portion.
A fuel filtration device comprising a resistance member between the inlet portion and the filter element that applies a greater flow resistance to the fuel flowing into the filter element at a portion closer to the inlet portion. . The resistance member has a plurality of openings,
The opening is
Arranged on the upstream side of the fuel flow at a distance from the peripheral wall on the fuel inflow side of the filter element;
2. The fuel filtering device according to claim 1, wherein an opening area of the opening is enlarged along a flow of fuel from the inlet to the outlet. The resistance member has a guide portion for restricting the flow of fuel,
The guide portion is
Arranged on the upstream side of the fuel flow at a distance from the peripheral wall on the fuel inflow side of the filter element;
2. The fuel filtration according to claim 1, further comprising a bent portion that restricts a fuel flow in a flow region on the peripheral wall side of the fuel flow that flows from the inlet portion along the outlet portion. apparatus. The guide portion is
The fuel flow restricted in the flow region on the peripheral wall side by the bent portion is merged with the fuel flow in the flow region on the anti-circumferential wall side with the guide portion interposed therebetween, and has a rectifying unit that rectifies the merged fuel flow. The fuel filtration device according to claim 3, wherein   The fuel filtering device according to claim 3 or 4, wherein the guide portion is a part of an inner wall of the filter casing. The filter element includes a filter medium that varies a thickness between a fuel inflow side and a fuel outflow side,
The filter medium is
The fuel filtering device according to any one of claims 1 to 5, wherein the portion closer to the inlet portion is formed with a larger thickness with respect to the fuel flowing into the filter element. A filter element provided between the fuel tank and the internal combustion engine, for collecting a collection target in the fuel supplied to the internal combustion engine; and an inlet portion and an outlet portion for accommodating the filter element therein and guiding the fuel A fuel filtration device that introduces fuel from the inlet portion of the filter casing, and derives the fuel from which the collection target has been removed by the filter element from the outlet portion.
The filter element includes a filter medium that varies a thickness between a fuel inflow side and a fuel outflow side,
The filter medium is
The fuel filtration device according to claim 1, wherein a portion closer to the inlet portion has a larger thickness than the fuel flowing into the filter element.   8. The filter element according to claim 1, wherein the filter element constitutes a filtering member that collects a foreign substance made of at least one of a metal and an organic substance or a metal ion as the collection target. The fuel filtration device according to one item.   9. The filter element according to claim 1, wherein the filter element constitutes an aggregating member that aggregates water particles in the fuel as the collection target and separates the aggregated water particles from the fuel. The fuel filtration device according to any one of the above.

Images