JP2013174236A - Moisture collecting device and fuel filter device with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture collecting device capable of facilitating drain maintenance operation, and to provide a fuel filter device having the moisture collecting device.SOLUTION: A fuel filter device 1 having a moisture collecting function includes flow back piping 30 which communicates a lower space 10b of a housing 10 with the interior of a fuel tank. When a low pressure pump is driven, a fuel pressure in the housing 10 comes to a positive pressure higher than the pressure in the fuel tank, a check valve 40 automatically is opened and, in accordance with a pressure difference between the interior of the housing 10 and the interior of the fuel tank, water collected from the interior of fuel flowing through a fuel passage in the housing 10 flows back into the fuel tank via the flow back piping 30.

Description

  The present invention relates to a moisture collection device that collects moisture contained in fuel and a fuel filter device that includes the moisture collection device.

  As a prior art, for example, there is a fuel filter device including a moisture collecting device disclosed in Patent Document 1 below. This fuel filter device is interposed, for example, in a fuel supply path from a fuel tank to a vehicle engine or the like. A water reservoir space for storing water separated from the fuel is formed in a housing including a case and a cap of the fuel filter device. When a considerable amount of water has accumulated in the water reservoir space, a user or the like rotates a drain plug for draining that is screwed to the bottom of the housing, and drains the water from the water reservoir space to the outside of the housing. It is like that.

JP 2000-345936 A

  However, in the water collecting device provided in the above-described conventional fuel filter device, when the water in the water reservoir space is discharged to the outside of the housing, the discharged water is received or drained from the discharged water. It is necessary to prevent the scattering of water. Therefore, there is a problem that the drainage maintenance work is relatively complicated.

  When the fuel pumped from the fuel tank by the pump means flows through the housing of the moisture collecting device, the fuel pressure in the housing becomes a positive pressure higher than the pressure in the fuel tank. I focused on that. That is, it has been found that when the fuel pressure in the housing becomes positive, the drainage maintenance work can be easily performed by using the pressure in the housing.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a moisture collection device capable of facilitating drainage maintenance work and a fuel filter device including the same.

In order to achieve the above object, in the present invention,
A housing in which a fuel passage through which positive pressure fuel pumped by the pump means flows is formed;
A reflux pipe that communicates the inside of the housing with the inside of the fuel tank, and that has a reflux path in which a fluid can flow back from the inside of the housing into the fuel tank due to a pressure difference between the inside of the housing and the fuel tank.
Water collected from the fuel flowing through the fuel passage in the housing is discharged to the outside of the housing through the reflux path.

  According to this, the water collected in the housing can be discharged to the outside of the housing through the reflux pipe using the pressure difference between the inside of the housing and the fuel tank. Therefore, there is no need to perform an operation for preventing the scattering of water when draining from the housing. In this way, the drainage maintenance work can be facilitated.

Further features of the invention include
A water storage tank that is provided in the reflux path and is separate from the housing;
Water draining means capable of discharging the water stored inside the water storage tank to the outside,
The water storage tank is capable of storing therein water collected in the housing and discharged to the outside of the housing through the reflux path.

  According to this, the water collected in the housing can be stored in a water tank separate from the housing by utilizing the pressure difference between the housing and the fuel tank. And the water stored in the water storage tank can be discharged to the outside by the water draining means. Since the water storage tank is provided separately from the housing, it is possible to dispose the water storage tank at a position where it is difficult for water to scatter when draining. Therefore, it is possible to easily perform the drainage maintenance work.

  A further feature of the present invention is that the water storage tank is disposed below the housing. According to this, the water storage tank provided separately from the housing can be easily disposed at a lower position where water is hardly scattered when draining.

  A further feature of the present invention is a moisture collecting device mounted on a vehicle, wherein the water storage tank is disposed outside the vehicle compartment and outside the engine compartment. According to this, the water storage tank can be arranged outside the vehicle compartment except for the engine room where maintenance work is difficult due to relatively many mounted devices. Therefore, the water storage tank can be mounted at a position where water drainage maintenance work is relatively easy.

In the present invention,
A housing in which a fuel passage through which positive pressure fuel pumped by the pump means flows is formed;
The inside of the housing and the fuel tank communicate with each other, and a reflux path is formed inside to recirculate the water collected from the fuel flowing through the fuel passage into the fuel tank due to the pressure difference between the inside of the housing and the fuel tank. A reflux tube,
The water collected in the housing is returned to the fuel tank through the return path.

  According to this, the water collected in the housing can be discharged into the fuel tank through the return pipe using the pressure difference between the housing and the fuel tank. Therefore, it is not necessary to perform an operation for preventing scattering of water discharged from the housing. In this way, the drainage maintenance work can be facilitated.

  Further, the present invention is further characterized by comprising a reflux path opening / closing means that is provided in the reflux pipe and opens the reflux path only when the inside of the housing is at a positive pressure. According to this, when the pump means is operated and the positive pressure fuel pumped from the fuel tank flows in the housing, the reflux path opening / closing means opens the reflux path, and the water in the housing is passed through the reflux pipe. It can be discharged out of the housing. Further, in the case of discharging the water collected in the housing into the fuel tank through the reflux pipe, it is possible to eliminate the drainage maintenance work. Further, when the pump means stops operating and the pressure in the housing decreases and the inside of the housing becomes the same pressure as the fuel tank, the return path is closed by the return path opening / closing means, and the fuel in the housing is It is possible to prevent the fuel tank from flowing out.

  Further, the present invention is further characterized in that the reflux path opening / closing means is a relief valve device that automatically opens only when the inside of the housing is at a positive pressure. According to this, it is not necessary to provide a control means for performing valve opening control when the pressure in the housing is positive. Further, in the case of discharging the water collected in the housing into the fuel tank via the reflux pipe, the drainage maintenance work can be eliminated with a relatively simple configuration.

  Further, in the fuel filter device of the present invention, the water collecting device having any one of the above-described features and the fuel collecting device provided in the fuel flow direction of the fuel passage in the housing on the downstream side of the water collecting device, And a filter member that captures foreign matter. According to this, the fuel after water is removed flows through the filter member. Therefore, it can suppress that water adheres to a filter member and filtration performance falls.

  In the fuel filter device of the present invention, the filter member is further characterized in that it is disposed above the upstream end of the reflux path in the direction of gravity. According to this, even if there is a foreign object that did not reach the filter member relatively heavy or a foreign object that fell once after being captured by the filter member, the pressure difference between the inside of the housing and the fuel tank is used, It can be discharged out of the housing from the upstream end of the reflux path below the filter member via the reflux pipe. Therefore, it is possible to prevent foreign matters not captured by the filter member from staying in the housing.

It is sectional drawing which shows the structure of the fuel filter apparatus 1 provided with the water | moisture-content collection apparatus in 1st Embodiment to which this invention is applied. 1 is a schematic configuration diagram of a common rail fuel injection system for a diesel engine that employs a fuel filter device 1 according to a first embodiment. It is a schematic block diagram of the common rail type fuel injection system for diesel engines which employ | adopted the fuel filter apparatus in 2nd Embodiment. It is sectional drawing which shows the structure of the water storage tank 70 in 2nd Embodiment. It is sectional drawing which shows the structure of a fuel filter apparatus provided with the water | moisture-content collection apparatus in other embodiment.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. In the case where only a part of the configuration is described in each embodiment, the other parts of the configuration are the same as those described previously. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination is not particularly troublesome.

(First embodiment)
A first embodiment to which the present invention is applied will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing a configuration of a fuel filter device 1 including a moisture collecting device (sedimenter) in a first embodiment to which the present invention is applied. FIG. 2 is a schematic configuration diagram of a common rail fuel injection system for a diesel engine that employs the fuel filter device 1.

  As shown in FIG. 2, the common rail fuel injection system of the present embodiment is mounted on a vehicle, for example, and includes a fuel tank 2, a supply pump 3, a common rail 4, and a low pressure pump 3 </ b> A of the supply pump 3. And a high-pressure pump 3B.

  The supply pump 3 is, for example, a low-pressure pump 3A (feed pump, low-pressure feed pump, equivalent to the pump means of the present embodiment) that can use a trochoid pump or vane pump, a solenoid valve as a flow control device, and For example, it is comprised from the high pressure pump 3B etc. which consist of plunger type pumps.

  The low pressure pump 3A and the high pressure pump 3B of the supply pump 3 are integrally configured and are driven by a common drive source. For example, the low-pressure pump 3A and the high-pressure pump 3B may be driven separately by separate driving sources.

  When the supply pump 3 is operated, the normal pressure fuel stored in the fuel tank 2 is sucked and flows through the fuel pipe 6 and supplied to the common rail 4. At that time, water and foreign matter are removed from the fuel in the fuel filter device 1.

  The common rail 4 holds the fuel pressurized by the high-pressure pump 3B of the supply pump 3 in an accumulated state. An injector (not shown) that injects fuel into each cylinder of the engine 5 is connected to the common rail 4 according to the number of cylinders, and the fuel held in the pressure accumulation state inside the common rail 4 is injected from the injector. The A recirculation pipe (not shown) is connected to the common rail 4, and surplus fuel in the common rail 4 is recirculated to the fuel tank 2 via the recirculation pipe.

  Low-pressure fuel that flows into the control pressure chamber of each injector and is discharged from an injector low-pressure port such as fuel and leak fuel used for the operation of the injector, and low-pressure fuel such as leak fuel from the supply pump 3 are also recirculated as described above. It joins the piping and returns to the fuel tank 2.

  Further, the common rail fuel injection system of the present embodiment is connected to an ECU (not shown) as a control means. This ECU optimally controls the flow rate of the fuel discharged from the supply pump 3 based on the input fuel pressure inside the common rail 4, the engine speed Ne, the accelerator opening α, and the like. Further, the ECU controls the opening / closing timing of the solenoid valve of the injector connected to the common rail 4. Thus, the fuel injection timing and the fuel injection amount into each cylinder of the engine are controlled.

  As shown in FIG. 1, the fuel filter device 1 includes a housing 10 in which a filter medium and the like are accommodated and a passage for fuel passing through the filter medium is formed. The housing 10 includes a case 11, a cover plate 12, a connection plate 13, and the like. The fuel filter device 1 is disposed so that the vertical direction in the drawing is the vertical direction. That is, the lower side in the figure is arranged to be the lower side in the direction of gravity.

  The case 11 constituting the outer shell of the housing 10 is formed, for example, by pressing a thin metal material, and is cup-shaped (bottomed cylindrical shape, specifically, a cylindrical portion and a relatively shallow portion that closes the lower end of the cylindrical portion. A shape composed of a bowl-shaped part). The cover plate 12 is formed, for example, by pressing a plate made of metal and thicker than the case 11 and is disposed so as to close the upper opening of the case 11. The connection plate 13 is formed by, for example, pressing a thin metal plate, and the lower surface is joined to the upper surface of the outer peripheral edge of the cover plate 12 by, for example, welding, and the outer peripheral edge is, for example, wound with the upper edge of the case 11. It is connected by staking.

  Thus, in the housing 10 in which the case 11, the cover plate 12, and the connection plate 13 are connected to each other, a filter member housing space that is a filter medium housing chamber sealed to the outside is formed. ing.

  A filter member 20 is housed in the filter member housing space in the housing 10. The filter member 20 includes a filter medium 24 made of nonwoven fabric, an outer cylinder 21 surrounding the outer periphery of the filter medium 24, an upper end plate 22 disposed over the entire area above the filter medium 24, and a central opening of the upper end plate 22. The center cylinder 23 extends upward. The outer cylinder 21, the upper end plate 22, and the central cylinder 23 are integrally formed of, for example, a resin material.

  The central part of the cover plate 12 is formed in a cylindrical shape extending in the vertical direction, and the central cylinder 23 of the filter member 20 is fitted to the outer periphery of the cylindrical part. Further, the outer cylinder 21 of the filter member 20 is formed with an extending portion 21 a extending downward in a part of the circumferential direction, and the lower end of the extending portion 21 a is formed on the upper surface of the bottom portion of the case 11. It is in contact. Thereby, the filter member 20 is accommodated in a predetermined position in the housing 10.

  The filter member 20 is accommodated in a predetermined position in the housing 10, and an upper space 10a and a lower space 10b are formed above and below the filter medium 24 in the housing 10. The outer diameter of the outer cylinder 21 of the filter member 20 is slightly smaller than the inner diameter of the case 11, and the upper space 10 a and the lower space 10 b are formed between the outer cylinder 21 and the cylindrical portion of the case 11. It communicates through a passage.

  Above the housing 10, a joint block body 50 (fluid lead-in / out path forming member) is disposed. The joint block body 50 is made of, for example, metal, and a male screw portion is formed on an outer peripheral surface of a portion protruding downward from a substantially central portion of the lower surface. The male screw portion is screwed into a female screw portion formed on the inner peripheral surface of a cylindrical portion formed in the center portion of the cover plate 12.

  On the upper surface of the connection plate 13 described above, an annular groove portion is formed with the axis of the screwing portion as the center. In this groove portion, an O-ring 14 is disposed as a seal member that is compressed between the connection plate 13 and the joint block body 50 and seals the internal space and the external space.

  Inside the joint block body 50, various passages for introducing and extracting fluid into the housing 10 are formed. Specifically, the joint block body 50 has a fuel introduction passage 51 for introducing fuel pumped from the low pressure pump 3A into the housing 10, and a fuel lead-out for leading the fuel in the housing 10 to the high pressure pump 3B. A passage 52 and an air outlet passage 53 for leading the air in the housing 10 to the fuel tank 2 are formed.

  A fuel pipe 6 extending from the low pressure pump 3 </ b> A is connected to the inlet portion of the fuel introduction passage 51. The outlet portion of the fuel introduction passage 51 is open between the screwed portion with the cover plate 12 and the seal portion by the O-ring 14 on the lower surface of the joint block body 50. The cover plate 12 of the housing 10 is provided with an opening between the threaded portion and the connection plate 13 joint portion. With this configuration, the outlet portion of the fuel introduction passage 51 communicates with the upper space 10a in the housing 10 via the communication space 54 (the space between the cover plate 12 and the joint block body 50).

  The fuel outlet passage 52 is formed coaxially with the screwing portion. The inlet portion of the fuel outlet passage 52 is opened inside the central cylinder 23 above the filter medium 24. A fuel pipe 6 extending to the high pressure pump 3 </ b> A is connected to the outlet of the fuel outlet passage 52.

  The inlet portion of the air lead-out passage 53 opens between the screwed portion with the cover plate 12 and the seal portion by the O-ring 14 on the lower surface of the joint block body 50. Therefore, the inlet portion of the air outlet passage 53 communicates with the upper space 10 a in the housing 10 via the communication space 54. An air pipe 31 extending into the fuel tank 2 is connected to the outlet of the air outlet passage 53.

  The air outlet passage 53 is provided with a check valve 60 that allows a fluid flow from the inlet portion to the outlet portion and prohibits a fluid flow from the outlet portion to the inlet portion. The check valve 60 includes a spherical valve body 62 and a spring 63 that urges the spherical valve body 62 toward the upstream side.

  In the case 11 of the housing 10, an opening is formed at the center of the bottom (the lowest part of the bowl-shaped bottom), and the upstream end of the return pipe 30 (corresponding to the return pipe) extending to the fuel tank 2 is connected to this opening. Yes. A check valve 40 is provided at the most upstream portion of the reflux pipe 30 to allow the flow of fluid from the housing 10 into the fuel tank 2 and prohibit the flow of fluid from the fuel tank 2 into the housing 10. ing.

  Specifically, the most upstream part of the reflux pipe 30 constitutes a valve housing 41. The outer peripheral surface of the valve housing 41 is joined to the opening at the bottom of the case 11 by, for example, brazing, over the entire circumference. A spherical valve body 42 and a spring 43 that urges the spherical valve body 42 toward the upstream side are provided in the valve housing 41, thereby constituting a check valve 40.

  A part of the valve housing 41 that constitutes the most upstream part of the reflux pipe 30 protrudes upward from the bottom of the housing 10. And the inlet part of the reflux piping 30 is formed in the front-end | tip part of a protrusion direction. That is, the upstream end of the reflux path formed inside the reflux pipe 30 opens to the lower space 10 b below the filter medium 24 of the filter member 20. The reflux path communicates the lower space 10 b in the housing 10 and the fuel tank 2.

  As shown in FIG. 2, the reflux pipe 30 is joined and connected outside the air pipe 31 and the fuel tank 2. The valve opening set pressure of the check valve 40 and the valve opening set pressure of the check valve 60 in the air outlet passage 53 are substantially the same pressure which is relatively low. The reflux pipe 30 and the air pipe 31 each have a passage cross-sectional area smaller than that of the fuel pipe 6. Thus, a large amount of liquid fuel is prevented from returning to the fuel tank 2 through the return pipe 30 and the air pipe 31.

  In the fuel filter device 1 configured as described above, when the supply pump 3 shown in FIG. 2 is driven, the liquid fuel in the fuel tank 2 is pumped by the low-pressure pump 3A, and the communication space 54 passes through the fuel introduction passage 51 shown in FIG. To the upper space 10 a in the housing 10. The liquid fuel introduced into the upper space 10 a flows through a passage formed between the outer cylinder 21 of the filter member 20 and the cylindrical portion of the case 11 and flows into the lower space 10 b in the housing 10.

  In the lower space 10b, water or the like that has been aggregated and separated from the fuel that has flowed in settles, and water having a specific gravity greater than that of the fuel oil is sequentially stored in the lower space 10b in the housing 10 from the bottom. It can be said that the lower space 10b in the housing 10 is a storage space (storage part) of water collected from the fuel.

  The fuel that has flowed into the lower space 10b passes upward through the filter medium 24 of the filter member 20, and at this time, unseparated fine water droplets are aggregated and foreign matters are removed. The fuel that has passed through the filter medium 24 and from which moisture and foreign matter have been removed is led out from the housing 10 through the fuel lead-out passage 52 and sent to the high-pressure pump 3B.

  In the fuel supply system (common rail fuel injection system) of the present embodiment, a low pressure pump 3A is interposed between the fuel tank 2 and the fuel filter device 1. Accordingly, the liquid fuel flowing in the housing 10 of the fuel filter device 1 is pressurized by the low pressure pump 3A, and becomes a positive pressure higher than the pressure in the fuel tank 2. The fuel tank 2 of the present embodiment has a configuration in which the internal pressure is substantially atmospheric pressure, and the pressure in the housing 10 is a positive pressure higher than the atmospheric pressure in the present embodiment.

  The “positive pressure” referred to in the present invention is based on the pressure in the fuel tank. The fuel in the fuel tank 2 is pumped by the low-pressure pump 3 </ b> A serving as pump means, and a fuel having a positive pressure higher than the pressure in the fuel tank 2 flows through the fuel passage in the housing 10 of the fuel filter device 1.

  As described above, when the low-pressure pump 3A is driven, the check valve 40 and the check valve 60 are automatically opened due to the positive pressure in the housing 10. Here, in this embodiment, the check valve 40 is a return path opening / closing means that opens the return path in the return pipe 30 only when the inside of the housing 10 is at a positive pressure, and when the inside of the housing 10 is at a positive pressure. This corresponds to a relief valve device that automatically opens only.

  When the check valve 40 is opened, a reflux path in the reflux pipe 30 is opened, and a part of the fluid in the lower space 10b is made to be a fuel tank due to a difference between the pressure in the housing 10 and the pressure in the fuel tank 2. Reflux into 2. In the lower space 10b, moisture collected and collected from the flowing fuel is stored from the bottom. Therefore, when the check valve 40 is opened, the water collected and collected from the fuel in the lower space 10 b is mainly returned to the fuel tank 2.

  At this time, among foreign matters mixed in the fuel flowing into the lower space 10b, foreign matters such as dust that has been relatively heavy and did not reach the filter medium 24, or once captured by the filter medium 24, Foreign matter such as dust that has fallen off is also sent into the fuel tank 2 through the return path in the return pipe 30.

  In the fuel filter device 1 shown in FIG. 1, the upstream end of the reflux path opens slightly above the lowermost part of the lower space 10 b in the housing 10. When the low-pressure pump 3A is driven, water may be stored below the opening position of the upstream end of the reflux path in the housing 10, but it is collected and collected from the fuel above the opening position. Water immediately flows into the reflux path. Therefore, in the lower space 10b in the housing 10, the region below the upstream end opening position of the reflux path is a substantial water storage portion.

  When the low-pressure pump 3A is stopped (when the supply pump 3 is stopped), the water collected and collected from the fuel staying in the housing 10 is opened at the upstream end of the reflux path. There is a case where it accumulates above the position. In this case, a region obtained by adding a region for storing water above the return path upstream end opening position to a region below the upstream end opening position of the return path may be referred to as a water storage portion in the housing 10. it can.

  The upstream end of the reflux path may be provided at the lowermost part of the lower space 10 b in the housing 10. In other words, the reflux pipe may communicate between the lowermost part in the housing and the inside of the fuel tank. In such a configuration, when the low-pressure pump 3 </ b> A is being driven, the water that is condensed and collected from the fuel quickly flows into the reflux path and is not stored in the housing 10. Therefore, when the upstream end of the reflux path is opened at the lowermost part in the housing 10, no water storage portion is formed in the housing 10. However, as described above, when the low-pressure pump 3A is stopped and water collected and collected from the fuel remaining in the housing 10 is stored in the lower space 10b in the housing 10, It can be said that the area where water is stored is the storage part. When a water storage part is formed in the housing 10, the storage part is formed in a lower part (a part including the lowest part) in the housing 10.

  Further, the low pressure pump 3A is driven and the inside of the housing 10 becomes positive pressure, and the check valve 60 is opened, thereby opening a reflux path that connects the inside of the housing 10 and the inside of the fuel tank 2 through the air pipe 31. Accordingly, due to the difference between the pressure in the housing 10 and the pressure in the fuel tank 2, part of the fluid in the upper space 10 a and the communication space 54 in the housing 10 is returned to the fuel tank 2.

  For example, when a gas such as air that flows in along with the fuel exists in these spaces, the gas is recirculated into the fuel tank 2 via a path in the air pipe 31. A lot of fuel vapor is mixed in the air existing in the upper space 10a and the communication space 54 of the housing 10. By letting such air flow into the fuel tank 2, the fuel vapor can be prevented from leaking outside.

  According to the configuration and operation described above, the fuel filter device 1 includes the return pipe 30 that communicates the lower space 10 b of the housing 10 and the inside of the fuel tank 2. When the low pressure pump 3A is driven, the fuel pressure in the housing 10 becomes a positive pressure higher than the pressure in the fuel tank 2 and the check valve 40 is automatically opened to collect from the fuel flowing through the fuel passage in the housing 10. The water thus discharged is discharged to the outside of the housing 10 through the reflux pipe 30 due to a pressure difference between the housing 10 and the fuel tank 2.

  According to this, the water collected in the housing 10 can be discharged to the outside of the housing 10 via the reflux pipe 30 using the pressure difference between the housing 10 and the fuel tank 2. Therefore, there is no need to perform water scattering prevention work when draining from the inside of the housing 10. In this way, the drainage maintenance work can be facilitated.

  Further, water collected from the fuel flowing through the fuel passage in the housing 10 is returned to the fuel tank 2 through the return pipe 30 due to a pressure difference between the inside of the housing 10 and the fuel tank 2.

  According to this, the water collected in the housing 10 can be discharged into the fuel tank 2 through the reflux pipe 30 using the pressure difference between the housing 10 and the fuel tank 2. Therefore, the drainage maintenance work can be eliminated. Further, when the low-pressure pump 3A stops operating and the pressure in the housing 10 decreases and the inside of the housing 10 becomes the same pressure as the inside of the fuel tank 2, the check valve 40 closes the return path. The fuel in 10 can be prevented from flowing into the fuel tank 2.

  The check valve 40 is automatically opened only when the low pressure pump 3A is driven and the inside of the housing 10 is at a positive pressure. Therefore, it is not necessary to provide a control means for performing valve opening control when the inside of the housing 10 is positive pressure. Thereby, the drainage maintenance work can be made unnecessary with a relatively simple configuration.

  Further, the filter medium 24 of the filter member 20 is disposed on the upper side, which is the downstream side in the fuel flow direction, with respect to the lower space 10b of the housing 10 that collects water from the fuel. Accordingly, since the fuel from which water has been removed flows through the filter medium 24, it is possible to prevent a large amount of water from adhering to the filter medium 24 and reducing the filtration performance. Thereby, the lifetime in which the filter member 20 can maintain the function can be extended.

  In addition, even if there is a foreign object that has not reached the filter medium 24 of the filter member 20 because it is relatively heavy, or a foreign object that has been once trapped by the filter medium 24 and has fallen down, the return path is lower than the filter member 20. The water can be discharged into the fuel tank 2 through the reflux pipe 30 together with water. Therefore, it is possible to prevent foreign matters not captured by the filter medium 24 of the filter member 20 from staying in the lower space 10 b of the housing 10.

  Further, the reflux pipe 30 and the air pipe 31 for discharging the air containing fuel vapor (gaseous fuel) from the upper part of the housing 10 into the fuel tank 2 merge in the middle of the path, and share the downstream portions thereof. It is made of piping. Therefore, the total pipe length can be shortened and the configuration can be simplified as compared with the case where both pipes are individually arranged from the housing 10 to the fuel tank 2.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. 3 and FIG. The second embodiment is different from the first embodiment in that water collected in the housing 10 is discharged into the water storage tank 70.

  In addition, about the part similar to 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. Components having the same reference numerals as those in the drawings according to the first embodiment and other configurations not described in the second embodiment are the same as those in the first embodiment, and have the same effects. .

  As shown in FIG. 3, in the present embodiment, a water storage tank 70 is provided in the reflux pipe 30 that forms a reflux path therein (in the present example, at a position downstream of the junction of the reflux pipe 30 and the air pipe 31). It is arranged. The water storage tank 70 is separate from the housing 10 of the fuel filter device 1.

  As shown in FIG. 4, the water storage tank 70 is a container body that is made of, for example, a relatively inexpensive and lightweight resin and forms a water storage chamber (water storage chamber) 70 a having a relatively large volume therein. A water storage chamber 70a formed in the water storage tank 70 is sealed with respect to the outside.

  The water storage tank 70 has a fluid introduction pipe 71 for introducing a fluid into the inside, and a fluid outlet pipe 72 for guiding the fluid from the inside. The fluid introduction pipe 71 and the fluid outlet pipe 72 project from the side wall portion of the container body portion of the water storage tank 70 outward (in the left-right direction in FIG. 4) in a substantially horizontal direction.

  The fluid introduction pipe 71 and the fluid lead-out pipe 72 are provided in a relatively upper portion near the ceiling portion of the side wall portion of the water storage tank 70 container body. In this example, the fluid introduction pipe 71 and the fluid outlet pipe 72 are integrally formed in the container body portion of the water storage tank 70.

  A reflux pipe 30 extending from the fuel filter device 1 is connected to an inlet portion of the fluid introduction pipe 71. On the other hand, a reflux pipe 30 extending to the fuel tank 2 is connected to the outlet portion of the fluid outlet pipe 72.

  The water storage tank 70 is disposed so that the vertical direction in the figure is the top-bottom direction. That is, the lower side in the figure is arranged to be the lower side in the direction of gravity. A water level sensor 80 protruding from the bottom surface of the water storage tank 70 is provided in the water storage tank 70. The water level sensor 80 is a float-type water level detection unit including a float 81. The float 81 floats at the interface between water and fuel by suitably setting the average density.

  The float 81 is a float body having a magnet, for example, and detects the water level in the water storage tank 70 by switching on and off a switch (not shown) by magnetic force according to the vertical position of the float 81. ing. The water level detection means is not limited to the above type, and may be, for example, a device that detects the water level based on the energization characteristics between the electrodes.

  A drain port 73 is formed at the lowermost portion of the side wall of the water storage tank 70. A drain plug (drain plug) 74 as a drain means is screwed into the drain port 73. The drain plug 74 includes an O-ring 74a serving as a seal member attached to the outer peripheral surface portion on the distal end side (right side in the drawing) in the screwing direction. The drain plug 74 has a male screw portion formed on the outer peripheral surface on the base end side (left side in the drawing) of the O-ring 74a mounting portion.

  On the other hand, the drain port 73 is formed with an internal thread portion that engages with the external thread portion of the drain plug 74 on the inner peripheral surface. A drain hole 74 b is formed through the drain plug 74. The outer end of the drain hole 74 b opens to the outside of the water storage tank 70. On the other hand, the inner end of the drain hole 74b opens into the drain port 73 on the outer side (the left side in the figure) of the O-ring 74a mounting portion.

  With such a configuration, when the drain plug 74 is rotated and the drain plug 74 is retracted to the left in the figure, the sealing structure by the O-ring 74a is released, and the water stored in the water storage chamber 70a is drained. The water can be drained to the outside of the water storage tank 70 through the drainage hole 74b.

  In addition, the formation position of the drain port 73 is not limited to the lowest part of the side wall part of the water storage tank 70, For example, you may form in the bottom face part of the water storage tank 70.

  In the configuration of the present embodiment, when the supply pump 3 shown in FIG. 3 is driven, the liquid fuel in the fuel tank 2 is pumped by the low-pressure pump 3A, and the fuel is passed through the fuel filter device 1 as in the first embodiment. Circulate. At this time, when the check valve 40 is opened by the positive pressure in the housing 10, the water collected from the fuel in the housing 10 of the fuel filter device 1 passes through the reflux pipe 30 and flows into the fuel filter device 1. The water is discharged from the housing 10 into the water storage tank 70.

  In the recirculation pipe 30, water collected and collected mainly from the fuel flows, but the fuel also flows along with the water. Therefore, water and fuel are introduced into the water storage tank 70 via the fluid introduction pipe 71. In this example, since the water storage tank 70 is provided in a common pipe portion of the reflux pipe 30 and the air pipe 31, not only water and fuel but also air containing a large amount of fuel vapor is contained in the water storage tank 70. Inflow. In the water storage tank 70, water having the largest specific gravity among these fluids is separated from other fluids and stored from the bottom.

  When the water level stored in the water storage tank 70 reaches a predetermined water level, the water level sensor 80 detects the predetermined water level and activates a notification means such as a warning light (not shown). Then, when a user or the like who has recognized the notification operates the drain plug 74, water is discharged from the water storage tank 70.

  In the water storage tank 70, a region below a predetermined water level detected by the water level sensor 80 is a substantial water storage chamber 70a. In the water storage tank 70, the region above the predetermined water level is a part that functions as a separation region for separating water from the fluid introduced into the water storage tank 70 via the fluid introduction pipe 71.

  The formation position of the fluid introduction pipe 71 in the water storage tank 70 is preferably above the predetermined water level. By providing the fluid introduction pipe 71 in this way, it is possible to prevent the water separated from the fluid and stored in the water storage chamber 70a from being rolled up by the flow of the fluid flowing into the water storage tank 70.

  Moreover, it is preferable that the formation position of the fluid outlet pipe 72 in the water storage tank 70 is also above the predetermined water level. By providing the fluid outlet pipe 72 in this way, it is possible to prevent the water stored in the water storage chamber 70a from being sucked out by the flow of the fluid derived from the water storage tank 70.

  The water storage tank 70 is formed as a separate body from the housing 10 of the fuel filter device 1. Therefore, the degree of freedom for setting the mounting position in the vehicle is large. Therefore, the water storage tank 70 is preferably disposed below the fuel filter device 1. If the water storage tank 70 is disposed relatively downward, the drain plug 74 can be easily operated from the lower side of the vehicle. In addition, since the drain port 73 is relatively close to the stop surface (ground or floor surface) on which the vehicle is stopped, water is not easily scattered over a wide area when draining from the drain port 73.

  Moreover, the water storage tank 70 is outside the passenger compartment in the vehicle and can be easily mounted at a position other than the engine room. For example, the water storage tank 70 can be mounted at a position adjacent to the fuel tank 2.

  According to the present embodiment, as in the first embodiment, when the low pressure pump 3A is driven, the fuel pressure in the housing 10 becomes a positive pressure higher than the pressure in the fuel tank 2, and the check valve 40 is automatically opened. The water collected from the fuel flowing through the fuel passage in the housing 10 is discharged to the outside of the housing 10 through the return pipe 30 due to a pressure difference between the inside of the housing 10 and the inside of the fuel tank 2.

  According to this, the water collected in the housing 10 can be discharged to the outside of the housing 10 via the reflux pipe 30 using the pressure difference between the housing 10 and the fuel tank 2. Therefore, there is no need to perform water scattering prevention work when draining from the inside of the housing 10. In this way, the drainage maintenance work can be facilitated.

  A recirculation path formed by the recirculation pipe 30 is provided with a water storage tank 70 separate from the housing 10, and the water storage tank 70 is provided with a drain plug 74 capable of discharging the water stored inside. It has been. The water storage tank 70 can store therein water collected in the housing 10 and discharged to the outside of the housing 10 through the reflux path.

  According to this, the water collected in the housing 10 can be stored in the water storage tank 70 separate from the housing 10 using the pressure difference between the housing 10 and the fuel tank 2. The water stored in the water storage tank 70 can be discharged to the outside by operating the drain plug 74. Since the water storage tank 70 is provided separately from the housing 10, the water storage tank 70 can be disposed at a position where it is difficult for water to scatter when the drain plug 74 is operated to drain water. Therefore, it is possible to easily perform the drainage maintenance work.

  Further, since the water storage tank 70 is separate from the fuel filter device 1, the capacity of the water storage tank 70 (volume of the water storage chamber 70a) can be made relatively large. According to this, the interval of drainage maintenance can be made relatively long. Moreover, since the inside of the water storage tank 70 is a low pressure that is closer to the atmospheric pressure than the positive pressure inside the housing 10, it is easy to increase the capacity of the water storage tank 70.

  The water storage tank 70 is disposed below the housing 10. According to this, the water storage tank 70 provided separately from the housing 10 can be easily disposed at a lower position where it is difficult for water to scatter when draining.

  The water storage tank 70 is disposed outside the vehicle compartment and outside the engine room. According to this, the water storage tank 70 can be disposed outside the vehicle room except for the engine room where maintenance work is difficult because there are relatively many devices such as auxiliary machines. Therefore, the water storage tank 70 can be mounted at a position where water drainage maintenance work is relatively easy.

  In addition, in this embodiment, although the water storage tank 70 was provided in the downstream site | part rather than the confluence | merging point of the reflux piping 30 and the air piping 31, it is not limited to this. For example, the water storage tank 70 may be provided in a portion of the recirculation pipe 30 that is downstream of the check valve 40 and upstream of the junction with the air pipe 31.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the above embodiment, the check valve 40 provided in the return pipe 30 as the return path opening / closing means that opens the return path only when the inside of the housing 10 is positive pressure is the pressure between the upstream side and the downstream side of the spherical valve body 42. Although the relief valve device automatically opens due to the difference, the present invention is not limited to this.

  For example, as shown in FIG. 5, an electromagnetic valve 140 may be provided in the reflux pipe 30 as the reflux path opening / closing means. A water level sensor 80 provided with a float 81 is provided in the lower space 10b in the housing 10, and the control device 90, which is a control means, is operated by a detection signal from the water level sensor 80 when the low pressure pump is operating (when the fuel supply system is operating). The solenoid valve 140 may be subjected to valve opening control when it is detected that the stored water level of the lower space 10b (reserving part) in the gas reaches a predetermined water level.

  A user who has provided a manually operated on-off valve in the reflux pipe 30 and activates a warning light or other notification means when the water level in the lower space 10b (storage part) in the housing 10 reaches a predetermined water level, and recognizes the notification. For example, the opening / closing means may be operated when the pump means is operated to discharge water from the housing 10 to the outside of the housing 10 (for example, water is recirculated from the inside of the housing 10 to the fuel tank 2).

  In the above embodiment, the check valve 40 is provided in the reflux pipe 30, but the reflux pipe 30 is not provided with a reflux path opening / closing means, and the lower space 10 b (preferably the lowermost part) in the housing 10 is provided by the reflux pipe 30. The fuel tank 2 may be in continuous communication with the fuel tank 2.

  Moreover, in the said embodiment, although the filter member 20 was arrange | positioned above the lower space 10b which capture | acquires water from fuel, it is not limited to this. The filter member should just be provided in the site | part through which the fuel after water is collected flows. If a filter member is provided on the downstream side of the fuel flow with respect to the moisture collection function unit (moisture collection device), it is possible to suppress a reduction in filtration performance due to a large amount of water adhering to the filter member. .

  Moreover, although the said embodiment demonstrated the case where the fuel filter apparatus 1 was employ | adopted as the common rail type fuel injection system for diesel engines, it is not limited to this. For example, the present invention may be applied to a fuel filter device of a fuel supply system for a gasoline engine. A pump means may be provided between the fuel tank and the fuel filter device including the moisture collecting device, and the positive pressure fuel pumped by the pump means may circulate through the fuel passage in the housing of the fuel filter device.

  Further, the fuel filter device 1 is not limited to the one mounted on the vehicle, and may be a stationary type, for example.

  Further, it may be a moisture collecting device (segimentor) not provided with a filter member. A pump means may be provided between the fuel tank and the water collecting device, and the positive pressure fuel pumped by the pump means may circulate through the fuel passage in the housing of the water collecting device.

  Moreover, in the said embodiment, in the lower space 10b in the housing 10, the water which aggregated from the fuel which flowed into the lower space 10b was settled and collected, but the member which promotes the aggregation of water is employ | adopted. It doesn't matter. For example, an aggregation promoting member may be disposed at the entrance to the lower space 10 b in the housing 10.

  The pump means may be disposed outside the fuel tank or may be disposed within the fuel tank. Further, the type of fuel flowing through the fuel passage in the housing 10 is not limited. For example, the fuel may be light oil or gasoline.

  Moreover, in the said embodiment, although the pressure in the fuel tank 2 was atmospheric pressure, it is not limited to this. For example, the fuel tank may be a sealed high-pressure tank that stores LPG fuel. The present invention is applied to a water collecting device or a fuel filter device equipped with a water collecting device as long as the pressure of the fuel flowing through the fuel passage in the housing is a positive pressure higher than the pressure in the fuel tank. It is effective.

DESCRIPTION OF SYMBOLS 1 Fuel flow filter apparatus 2 Fuel tank 3A Low pressure pump (pump means)
10 Housing 10b Lower space (reservoir)
20 Filter member 24 Filter medium 30 Reflux pipe (reflux pipe)
40 Check valve (return path opening / closing means, relief valve device)
70 Water storage tank 74 Drain plug (water draining means)
140 Solenoid valve (return path opening / closing means, relief valve device)

Claims (9)

A housing in which a fuel passage through which positive pressure fuel pumped by the pump means flows is formed;
A recirculation path is formed inside the housing and the fuel tank, and a recirculation path is formed in the fluid tank to recirculate fluid from the housing into the fuel tank by a pressure difference between the housing and the fuel tank. A tube, and
A water collecting apparatus, wherein water collected from the fuel flowing through the fuel passage in the housing is discharged to the outside of the housing through the reflux path. A water storage tank provided in the reflux path, separate from the housing;
Drainage means capable of discharging the water stored in the water storage tank to the outside, and
The water collecting apparatus according to claim 1, wherein the water storage tank is capable of storing the water collected and discharged to the outside of the housing through the reflux path.   The water collecting apparatus according to claim 2, wherein the water storage tank is disposed below the housing. Mounted on the vehicle,
The water collecting apparatus according to claim 2 or 3, wherein the water storage tank is disposed outside the vehicle compartment and outside the engine room.   The water collecting apparatus according to claim 1, wherein the collected water is recirculated into the fuel tank through the recirculation path.   The moisture according to any one of claims 1 to 5, further comprising a reflux path opening / closing means that is provided in the reflux pipe and opens the reflux path only when the inside of the housing is at a positive pressure. Collection device.   The moisture collecting device according to claim 6, wherein the reflux path opening / closing means is a relief valve device that automatically opens only when the inside of the housing is at a positive pressure. The moisture collection device according to any one of claims 1 to 7,
A fuel filter device comprising: a filter member provided downstream of the moisture collection device in the fuel flow direction of the fuel passage and capturing foreign matter in the fuel.   9. The fuel filter device according to claim 8, wherein the filter member is disposed above the upstream end of the reflux path in the direction of gravity.

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