Patent Publication Number: US-11396856-B2

Title: Fuel supply device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a 35 U.S.C. § 371 U.S. National Phase entry of, and claims the benefit of, PCT Application No. PCT/JP2019/038762 filed Oct. 1, 2019, which claims priority to Japanese Patent Application No. 2018-194220 filed Oct. 15, 2018, each of which is incorporated herein by reference in their entirety for all purposes. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND 
     The present disclosure generally relates to fuel supply devices. 
     One type of fuel supply device includes a fuel pump, a sub-tank, a leakage passage, and a fuel filter as, for example, shown in International Patent Publication No. WO2017/141628. The fuel filter is disposed at a bottom of the sub-tank and includes a bag-like filter member for filtering fuel to be suctioned into the fuel pump. When the fuel pump is driven, the fuel pump suctions the fuel in a fuel tank and the fuel in the sub-tank via the fuel filter. The fuel pump pressurizes and discharges the fuel to an engine. A part of the pressurized fuel discharged from the fuel pump flows back to the sub-tank through the leakage passage. At that time, the pressurized fuel is jetted from the leakage passage toward the filter member. 
     SUMMARY 
     In one aspect of this disclosure, a fuel supply device for supplying a fuel in a fuel tank to an engine includes a fuel pump, a sub-tank configured to store the fuel, a pressurized fuel return passage configured to return a part of a pressurized fuel discharged from the fuel pump into the sub-tank, and a fuel filter disposed at a bottom part of the sub-tank. The fuel filter includes a filter member that has a bag-like shape and is configured to filter the fuel to be suctioned into the fuel pump. A downstream end of the pressurized fuel return passage includes a linear passage part extending linearly from a position above the filter member toward the filter member. The fuel supply device includes a wall member configured to change a flow direction of the pressurized fuel jetted from the linear passage part, so as to prevent the pressurized fuel from running into the filter member. 
     In accordance with the aspect, the flow direction of the pressurized fuel jetted from the linear passage part of the pressurized fuel return passage is changed by the wall member. Thus, the wall member can prevent the pressurized fuel from violently colliding with the filter member, so that a strong impact on the filter member of the fuel filter by the pressurized fuel can be avoided. Accordingly, deformation of the filter member of the fuel filter caused by the pressurized fuel jetted from the pressurized fuel return passage can be suppressed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a first embodiment of a fuel supply device including a pump unit in accordance with the principles described herein. 
         FIG. 2  is a front view of the fuel supply device of  FIG. 1 . 
         FIG. 3  is a rear view of the fuel supply device of  FIG. 1 . 
         FIG. 4  is a plan view of the pump unit of the fuel supply device of  FIG. 1 . 
         FIG. 5  is a partial cross-sectional front view of the pump unit of  FIG. 4 . 
         FIG. 6  is a perspective view of a left part of the pump unit of  FIG. 4 . 
         FIG. 7  is a cross-sectional side view of the fuel receiving pipe part of the pump unit of  FIG. 4 . 
         FIG. 8  is a cross-sectional view of the end part of the discharge pipe part of the pump case of the pump unit of  FIG. 4 . 
         FIG. 9  is a side view of the leakage passage forming member of the pump unit of  FIG. 4 . 
         FIG. 10  is a perspective view of the direction change wall part of the second cap of the leakage passage forming member of  FIG. 9 . 
         FIG. 11  is a cross-sectional view of a part of a second embodiment of a fuel supply device in accordance with the principles described herein, which illustrates a surrounding area around a pressure regulator. 
     
    
    
     DETAILED DESCRIPTION 
     As described above, International Patent Publication No. WO2017/141628 discloses one type of fuel supply device to be disposed in a fuel tank and that includes a fuel pump, a sub-tank, a leakage passage, and a fuel filter. The fuel filter is disposed at a bottom of the sub-tank and includes a bag-like filter member. When the fuel pump is driven, the fuel pump suctions both the fuel in the fuel tank and the fuel in the sub-tank via the fuel filter, and then pressurizes and discharges the fuel to an engine. A part of the pressurized fuel discharged from the fuel pump flows back to the sub-tank through the leakage passage. At that time, the pressurized fuel is jetted from the leakage passage toward the filter member of the fuel filter, so that there is a possibility that the filter member could be undesirably concavely deformed from being impacted by the fuel jetted from the leakage passage. Therefore, there has been a need for an improved fuel supply device. 
     Referring now to  FIGS. 1 to 3 , a first embodiment of a fuel supply device  20  will be described. The fuel supply device  20  is disposed in a fuel tank  10  ( FIGS. 2 and 3 ) mounted on a vehicle, such as an automobile, having an engine, also referred to as an internal combustion engine. The fuel supply device  20  is configured to supply fuel in the fuel tank  10  to the engine.  FIG. 1  is a perspective view of the fuel supply device  20 ,  FIG. 2  is a front view of the same, and  FIG. 3  is a rear view of the same. In  FIGS. 1 to 3 , forward, rearward, rightward, leftward, upward, and downward directions are shown and generally correspond to orientations of the vehicle. In other words, the front-rear direction corresponds to the lengthwise direction of the vehicle, the right-left direction corresponds to the width direction of the vehicle, and the up-down direction corresponds to the height direction of the vehicle. In general, each of the front-rear direction and the right-left direction of the fuel supply device  20  may be changed in any horizontal direction. 
     As shown in  FIG. 2 , the fuel tank  10  is a hollow container having a top wall  11  and a bottom wall  12 . An opening  13  having a circular hole shape is formed in the top wall  11 . The fuel tank  10  is mounted on the vehicle, such that both the top wall  11  and the bottom wall  12  are horizontally oriented, i.e. are parallel with a vehicle body. The fuel tank  10  is made of resin, and thus, may deform (mainly expand and contract in the vertical direction) due to variation in the tank internal pressure. The fuel tank  10  is configured to store liquid fuel, such as gasoline, therein. 
     As shown in  FIG. 1 , the fuel supply device  20  includes a flange unit  22 , a joint member  24 , and a pump unit  26 . The joint member  24  is coupled to the flange unit  22  and the pump unit  26 , and allows the flange unit  22  and the pump unit  26  to move vertically relative to each other. 
     The flange unit  22  includes a flange body  28  having a lid plate part  32  with a circular plate shape as a main body. The flange body  28  is made of resin. As shown in  FIG. 2 , a fitting pipe part  33  having a short cylindrical shape is coaxially disposed on a lower surface of the lid plate part  32 . A flange part  34  having an annular plate shape is provided along an outer circumference of the lid plate part  32 . The flange part  34  extends radially outward beyond the fitting pipe part  33 . 
     As shown in  FIG. 1 , the lid plate part  32  is provided with a fuel outlet port  37 , a first electric connector  38 , and a second electric connector  39 . The fuel outlet port  37  has a linear pipe shape penetrating the lid plate part  32  in the vertical direction. A predetermined number of metal terminals are arranged in each of the electric connectors  38 ,  39 . 
     A canister part  150  has a hollow container shape and is formed at a rear portion of the flange body  28 . The canister part  150  is formed in substantially a semi-cylindrical shape that is coaxially aligned with the flange body  28 . The canister part  150  is filled with an adsorbent e.g. activated carbon configured to adsorb and desorb fuel vapor evaporated in the fuel tank  10 . An evaporation port  151 , an atmospheric port  152 , and a purge port  153  are provided at an upper surface of the flange body  28  and are in fluid communication with an internal space of the canister part  150 . A pair of right and left fixed side rails  155  extend linearly in the vertical direction, are provided on the front side of the canister part  150 , and are symmetrically arranged in the right-left direction (see  FIG. 2 ). 
     As shown in  FIG. 2 , the joint member  24  includes a joint body  46 , a spring guide  47 , and a pair of right and left movement side rails  157  coupled to the joint member  24 . The joint body  46  is made of resin. In addition, the joint body  46  has an elongated plate shape and is vertically oriented such that the joint body  46  is thin in the front-rear direction and extends in the vertical direction. An engagement shaft hole  50  is provided in a lower part of the joint body  46  and extends therethrough (see  FIG. 3 ). The spring guide  47  has a columnar shape and extends vertically upward from a central part of the joint body  46 . The movement side rails  157  extend linearly and vertically and are disposed on the right and left sides of the upper part of the joint member  24 . The movement side rails  157  are symmetrically arranged in the right-left direction relative to the joint body  46 . 
     The spring guide  47  of the joint member  24  is disposed in a spring  52  comprising a metal coil spring. In this state, the movement side rails  157  of the joint member  24  are moveably engaged with the fixed side rails  155  of the flange unit  22  such that the movement side rails  157  can move together relative to the fixed side rails  155  within a predetermined range in the vertical direction. That is, the joint member  24  is movably coupled to the flange unit  22  such that the joint member  24  and the flange unit  22  can move relative to each other in the vertical direction. The flange body  28  and the joint body  46  are biased apart in the separating direction due to the elasticity of the spring  52 . 
     As shown in  FIG. 2 , the pump unit  26  includes a sub-tank  54 , a sender gauge  56 , a fuel pump  58 , a pump case  60 , a pressure regulator  62 , and a regulator case  64 .  FIG. 4  is a plan view of the pump unit  26 ,  FIG. 5  is a partially cross-sectional front view of the same, and  FIG. 6  is a perspective view of a left part of the same. In  FIGS. 4 and 5 , the sender gauge  56  is not illustrated. 
     As shown in  FIG. 5 , the sub-tank  54  includes a sub-tank body  66 , a fuel filter  67 , and a cover member  68 . 
     The sub-tank body  66  is made of resin and has a shallow box shape with a lower opening. In particular, sub-tank body  66  has a rectangular shape elongated in the right-left direction in the plan view (see  FIG. 4 ). A square opening  70  is formed on the right side of an upper surface part of the sub-tank body  66 . The sub-tank body  66  includes a fuel receiving pipe part  71  having a substantially rectangular pipe shape. The fuel receiving pipe part  71  extends vertically upward from a left rear part of the upper surface of the sub-tank body  66  (see  FIG. 6 ). An upper end of the fuel receiving pipe part  71  is open. 
       FIG. 7  is a cross-sectional side view of the fuel receiving pipe part  71 . As show in  FIG. 7 , a guide pipe part  131  having a hollow, vertically oriented cylindrical shape is provided in the fuel receiving pipe part  71 . The guide pipe part  131  is disposed in a left portion of the fuel receiving pipe part  71 . A lower end of the guide pipe part  131  is open at a position above a lower surface of the sub-tank body  66 . The guide pipe part  131  is integrally formed with the fuel receiving pipe part  71  by utilizing a corner at the intersection of a left side part and a rear side part of the fuel receiving pipe part  71 . 
     As shown in  FIGS. 3 and 4 , rearwardly extending engagement shaft  72  is provided at a lower left part of a rear surface of the sub-tank body  66 . As shown in  FIG. 1 , the sub-tank body  66  includes a vertically oriented wall  73  having a plate shape. The vertically standing wall  73  faces in the front-rear direction and extends upward from a right rear part of the upper surface part of the sub-tank body  66 . 
     As shown in  FIG. 5 , the fuel filter  67  includes a filter member  75 , an internal frame member  76 , and a connection pipe  77 . The filter member  75  is configured to filter the fuel. The filter member  75  has a hollow bag-shape and is made of a filter medium that is comprised of a resin-made, non-woven fabric. The external shape of the filter member  75  is generally rectangular such that it is thin in the vertical direction and that its longitudinal direction corresponds to the right-left direction. 
     The internal frame member  76  is made of resin and has a frame structure holding the filter member  75  in a vertically expanded state. The connection pipe  77  is made of resin and has a vertically oriented cylindrical pipe shape. The connection pipe  77  is coupled to an upper part of the right side of the internal frame member  76  by thermal welding. An upper surface of the filter member  75  is held between the internal frame member  76  and the connection pipe  77 . The inside and the outside of the filter member  75  are in fluid communication with each other via the connection pipe  77 . 
     The filter member  75  is attached to the sub-tank body  66  to close the lower opening of the sub-tank body  66 . A fuel storing space  79  for storing the fuel is formed between the sub-tank body  66  and the filter member  75 . The connection pipe  77  is disposed in the opening  70  of the sub-tank body  66 . An annular space between the opening  70  and the connection pipe  77  functions as an inflow port  80  for the fuel. The fuel in the fuel tank  10  (see  FIG. 2 ) flows into the fuel storing space  79  through the inflow port  80  due to its own weight. 
     The cover member  68  is formed in a latticed plate shape. In particular, the cover member  68  has a rectangular plate shape including a plurality of openings. The cover member  68  is made of resin. The cover member  68  is attached to the sub-tank body  66  by snap-fit. A circumferential periphery of the filter member  75  is held between a circumferential periphery of the sub-tank body  66  and a circumferential periphery of the cover member  68 . The cover member  68  covers a lower surface of the filter member  75 . A plurality of projections  81  each having a hemispherical shape are formed and distributed on the lower surface of the cover member  68 . 
     As shown in  FIG. 7 , the guide pipe part  131  of the sub-tank body  66  is spaced apart from the filter member  75  by a predetermined distance in the vertical direction. 
     As shown in  FIG. 3 , the sender gauge  56  includes a gauge body  84 , an arm  85 , and a float  86 . The gauge body  84  is attached to a rear surface of the vertically standing wall  73  of the sub-tank body  66 . The gauge body  84  includes a rotation member  88  configured to rotate about a horizontal axis. Abase end of the arm  85  is attached to the rotation member  88 . A free end of the arm  85  opposite to the base end is coupled to the float  86 . The sender gauge  56  is a liquid level indicator for detecting the remaining amount of the fuel in the fuel tank  10 , i.e. the position of the liquid level. 
     As shown in  FIG. 5 , the fuel pump  58  comprises an electrical fuel pump having a substantially cylindrical shape. The fuel pump  58  includes a motor part and a pump part and is configured to suction the fuel, pressurize the fuel, and discharge the fuel. The fuel pump  58  has a fuel inlet  90  at its right end part on the pump part side and a fuel outlet  91  at its left end part on the motor part side. An electric connector is formed at the left end part of the fuel pump  58 . The motor part is comprised of, for example, a brushless continuous current motor. 
     The pump case  60  includes a case body  94  having a hollow cylindrical shape extending in the right-left direction. The pump case  60  is made of resin. The pump case  60  includes an end plate part  95  to close a left end opening of the case body  94 . The end plate part  95  includes a discharge pipe part  96  having a linear pipe shape penetrating the center of the end plate part  95 . A connecting pipe part  100  having a cylindrical pipe shape protruding upward is formed at a position near an end part of the discharge pipe part  96 . The internal space of the connecting pipe part  100  is in fluid communication with the internal space of the discharge pipe part  96 . 
     A passage, which includes internal passages of the discharge pipe part  96  and the connecting pipe part  100  and through which the pressurized fuel discharged from the fuel pump  58  flows, is referred to as a fuel passage  133 . An end part of the discharge pipe part  96  is connected to a leakage passage forming member  170 . The leakage passage forming member  170  will be described below. 
     The fuel pump  58  is housed in the case body  94  in a state where the fuel outlet  91  is directed to the left side. The fuel outlet  91  is connected to an outlet connection port  160  formed at a base end (right end) of the discharge pipe part  96 . 
     As shown in  FIG. 4 , a pair of front and rear elastic support pieces  102  are formed at an upper end part of the center of the case body  94  in the axial direction thereof. The elastic support pieces  102  extend from the case body  94  in opposite directions such that the elastic support pieces  102  are symmetric with respect to the front-rear direction. Each of the elastic support pieces  102  has an elongated sheet shape and is formed in an S-shape in the plan view. The ends of each elastic support piece  102  are attached to a front side part and a rear side part of the sub-tank body  66  by snap-fit. The pump case  60  is elastically supported on the sub-tank body  66  in a horizontal state, i.e. a laterally mounted state, via the elastic support pieces  102  (see  FIG. 5 ). 
     As shown in  FIG. 5 , a resin-made pump cap  104  for closing a right end opening of the case body  94  is attached to the case body  94  by snap-fit. The pump cap  104  includes a cap body  166  having a circular plate shape. A suction pipe part  105  having an elbow pipe shape is formed extends from the cap body  166 . The suction pipe part  105  has a horizontal part penetrating the cap body  166  and a vertical part extending downward from a right end of the horizontal part. An inlet connection port  168  is provided at a left end of the horizontal part of the suction pipe part  105  and is connected to the fuel inlet  90  of the fuel pump  58 . A lower end of the vertical part of the suction pipe part  105  is connected to the connection pipe  77  of the fuel filter  67  by snap-fit. 
     As shown in  FIG. 5 , the external shape of the pressure regulator  62  is substantially formed in a cylindrical shape. The pressure regulator  62  is configured to control the pressure of the pressurized fuel discharged from the fuel pump  58 , i.e. the fuel to be supplied to the engine, to a predetermined pressure, and to discharge an excess portion of the fuel. 
     The regulator case  64  is made of resin and has a hollow cylindrical container shape. The regulator case  64  includes a first case half  112  and a second case half  113 , which generally divide the regulator case  64  in the axial direction of the regulator case  64 . The case halves  112 ,  113  are coupled to each other by snap-fit. The pressure regulator  62  is housed in the regulator case  64 . The regulator case  64  is mounted with its axial direction horizontally oriented. 
     A connected pipe part  115  and a fuel discharge part  116  are formed on the first case half  112 . The connected pipe part  115  has a hollow cylindrical shape protruding downward from a lower part of the first case half  112 . The fuel discharge part  116  protrudes outward from an upper end part of the first case half  112  in a tangential direction. The connected pipe part  115  and the fuel discharge part  116  are in fluid communication with a fuel introduction port of the pressure regulator  62  in the first case half  112 . 
     An outlet pipe part  118  is formed at the second case half  113 . The outlet pipe part  118  protrudes downward from a right rear end part of the second case half  113 , i.e. an end part opposite to the first case half  112 . The outlet pipe part  118  is in fluid communication with an excess fuel outlet of the pressure regulator  62  in the second case half  113 . The fuel discharge part  116  is configured to discharge the fuel, the pressure of which is adjusted by the pressure regulator  62 . The excess fuel in the pressure regulator  62  is discharged from the outlet pipe part  118 . The outlet pipe part  118  is directed to the internal space of the fuel receiving pipe part  71  of the sub-tank body  66  (see  FIG. 6 ). 
     The connected pipe part  115  of the regulator case  64  is fitted and connected to the connection pipe part  100  of the pump case  60 . A check valve  120  is disposed in the connection pipe part  100 . The check valve  120  comprises a check valve for holding the residual pressure and is configured to prevent the reverse flow of the pressurized fuel in the connection pipe part  100 . The check valve  120  closes due to its own weight but can open in response to the pressure of the fuel. 
       FIG. 9  is a side view of the leakage passage forming member  170 . The leakage passage forming member  170  includes a leakage tube  172 , a first cap  174  coupled to one end of the leakage tube  172 , and a second cap  176  coupled to the other end of the leakage tube  172 . The leakage tube  172  and the caps  174 ,  176  are made of resin. The leakage tube  172  is comprised of a flexible tube. Internal passages of the first cap  174 , the leakage tube  172 , and the second cap  176  form a continuous leakage passage  178  (see  FIGS. 7 and 8 ). The leakage passage  178  is configured to return the pressurized fuel to the sub-tank  54 . The leakage passage  178  may also be referred to herein as a “pressurized fuel return passage.” The first cap  174  may also be referred to herein as an “upstream side passage member.” The second cap  176  may also be referred to herein as a “downstream side passage member.” 
       FIG. 8  is a cross-sectional view of an end part of the discharge pipe part  96  of the pump case  60 . As shown in  FIG. 8 , the first cap  174  has an elbow pipe shape and includes a cap part  175  and a connection port  179 . The cap part  175  has a hollow cylindrical shape with a closed side end. The connection port  179  has a hollow cylindrical shape protruding upward from the cap part  175 . The cap part  175  is configured to be connected to the end part of the discharge pipe part  96  of the pump case  60 . The connection port  179  has an inner diameter smaller than that of the cap part  175 . A restriction part  180 , which decreases the passage cross-sectional area, is formed in an upstream end part of the connection port  179 . The restriction part  180  is configured to restrict the leakage amount of the pressurized fuel, i.e. the amount of the pressurized fuel flowing through the leakage passage  178  to the sub-tank  54 . An end of the leakage tube  172  is connected to the connection port  179  by press-fitting. The cap part  175  is coaxially coupled to the end part of the discharge pipe part  96  by plastic welding. 
     As shown in  FIG. 7 , the second cap  176  includes a cap part  182  and a connection port  183 . The cap part  182  includes a pipe part  182   a  having a hollow cylindrical shape, and an end plate part  182   b  closing an upper end of the pipe part  182   a . The cap part  182  is configured to fit to and close an upper end opening of the guide pipe part  131  of the sub-tank body  66 . The connection port  183  is formed in a hollow cylindrical shape protruding upward from the center of the end plate part  182   b . The other end of the leakage tube  172  is connected to the connection port  183  by press-fitting. 
     A pair of front and rear engagement pieces  185  each having an engagement hole  186  are formed at an outer circumferential part of the end plate part  182   b  of the cap part  182 . A pair of front and rear engagement projections  187  are formed on an outer side surface of the upper end of the guide pipe part  131 . 
     The second cap  176  is attached to the guide pipe part  131  of the sub-tank body  66  by snap-fit. In particular, the engagement projections  187  are engaged with the corresponding engagement holes  186  via elastic deformation of the engagement pieces  185  by pressing the second cap  176  on the guide pipe part  131  from above. When the second cap  176  is attached to the guide pipe part  131 , the pipe part  182   a  of the cap part  182  is fitted in the upper end opening of the guide pipe part  131 . As a result, the end plate part  182   b  closes the upper end opening of the guide pipe part  131 . 
     An extended tube part  190  having a hollow cylindrical shape is formed at a lower end part of the connection port  183 . The extended tube part  190  protrudes downward from the center of the end plate part  182   b  of the cap part  182 .  FIG. 10  is a perspective view illustrating a direction change wall part  191  of the second cap  176 . As shown in  FIG. 10 , a lower end of the extended tube part  190  is almost covered by the direction change wall part  191 . A pressurized fuel jet port  193  having substantially a vertically elongated square shape is formed at one side of the extended tube part  190 . The direction change wall part  191  is formed in substantially a quarter of sphere shape, such that an inner surface of the direction change wall part  191  is concavely curved. The direction change wall part  191  may also be referred to herein as a “wall member.” The leakage passage  178  includes a linear portion, which is mainly defined by the connection port  183 , near the downstream end thereof. The linear portion of the leakage passage  178  may be referred to herein as a “linear passage part.” 
     An attachment of the pump unit  26  to the flange unit  22  will now be described. As shown in  FIG. 3 , the engagement shaft  72  of the sub-tank body  66  is rotatably disposed in the engagement shaft hole  50  of the joint body  46  coupled to the flange unit  22 . Thus, the pump unit  26  is rotatably coupled to the joint member  24  in the up-down direction (see i.e. the directions indicated by arrows Y 1  and Y 2  in  FIG. 3 ). 
     As shown in  FIG. 2 , the fuel outlet port  37  of the flange unit  22  is connected to the fuel discharge part  116  of the regulator case  64  of the pump unit  26  via a fuel discharge tube  124 . The fuel discharge tube  124  comprises a flexible tube made of resin or the like. 
     The first electric connector  38  of the flange unit  22  is electrically connected to the electric connector of the fuel pump  58  of the pump unit  26  via a first wire harness  126 . The second electric connector  39  of the flange unit  22  is electrically connected to the gauge body  84  (see  FIG. 3 ) of the pump unit  26  via a second wire harness  128 . The wire harnesses  126 ,  128  may be hooked on a wire hook part integrally formed on an adjacent resin-made member, as required. 
     An installation of the fuel supply device  20  will be described. The fuel supply device  20  is changed into an extended state for attaching it to the fuel tank  10 . In this state, the joint member  24  is suspended from the flange unit  22 , and the pump unit  26  is suspended from the joint member  24 . That is, the joint member  24  is moved downward to a lowermost position, i.e. the farthest position, relative to the flange unit  22 . Further, the pump unit  26  is rotated relative to the joint member  24  in the downward direction shown by the arrow Y 1  in  FIG. 3  to an inclined state (illustrated by the two-dot chain line  26  in  FIG. 3 ) where the right side of the pump unit  26  is inclined downward. 
     Next, the pump unit  26  is inserted into the opening  13  of the fuel tank  10  from above while keeping the fuel supply device  20  in the extended state. The pump unit  26  is changed to a horizontal state by rotating it relative to the joint member  24  in the direction opposite to the suspending process (i.e. the direction shown by the arrow Y 2  in  FIG. 3 ) and is disposed on the bottom wall  12  of the fuel tank  10  (see  FIGS. 2 and 3 ). A rotation restriction structure configured to prevent rotation of the pump unit  26  beyond the horizontal state is provided between the joint member  24  and the pump unit  26 . 
     Subsequently, the flange unit  22  is pressed downward against the biasing force of the spring  52 , so as to put the canister part  150  in the opening  13  of the fuel tank  10 . The flange part  34  of the flange body  28  is fixed on the top wall  11  of the fuel tank  10  by a fixing means (not shown), such as a metal fitting or a bolt. Installation of the fuel supply device  20  to the fuel tank  10  is completed by the above-described process. As a result, the flange unit  22  closes the opening  13  of the fuel tank  10 . 
     A fuel supply pipe connected to the engine is coupled to the fuel outlet port  37  of the flange unit  22 . External connectors are connected to the first electric connector  38  and the second electric connector  39 . A vapor passage connected to a breather pipe of the fuel tank  10  is coupled to the evaporation port  151 . The atmospheric port  152  is open to the surrounding atmosphere. A purge passage connected to an intake passage of the engine is coupled to the purge port  153 . 
     In the installation state of the fuel supply device  20  (see  FIGS. 2 and 3 ), the pump unit  26  is held such that it is pressed on the bottom wall  12  of the fuel tank  10  due to the biasing force of the spring  52 . In this state, the projections  81  of the cover member  68  abut the bottom wall  12  of the fuel tank  10 , so as to define the fuel flow through space between the cover member  68  and the bottom wall  12 . 
     When the internal pressure of the fuel tank  10  varies due to various factors, such as temperature variations or changes in the residual quantity of the fuel, the fuel tank  10  can deform, i.e. expand or contract, depending on the changes in the tank internal pressure. As a result, the distance between the top wall  11  and the bottom wall  12  of the fuel tank  10  changes, i.e. increases or decreases. In such case, the flange unit  22  and the joint member  24  vertically move relative to each other, so as to follow the height change of the fuel tank  10 . 
     An operation of the fuel supply device  20  will be described. The fuel pump  58  is driven by driving power supplied from the outside. Then, the fuel supplied from the fuel tank  10  via the cover member  68  and/or the fuel in the fuel storing space  79  of the pump unit  26  is suctioned into the fuel pump  58  via the fuel filter  67  and is pressurized therein. The pressurized fuel is discharged from the fuel pump  58  and flows into the regulator case  64  via the discharge pipe part  96  of the pump case  60 . In the regulator case  64 , the pressure regulator  62  controls the pressure of the pressurized fuel. The pressurized fuel having the controlled pressure flows through the fuel discharge tube  124  and is supplied from the fuel outlet port  37  of the flange unit  22  to the engine. The excess fuel resulting from the pressure controlled by the pressure regulator  62  is discharged from the outlet pipe part  118  of the regulator case  64  into the fuel receiving pipe part  71  of the sub-tank body  66 . 
     The fuel vapor evaporated in the fuel tank  10  is introduced from the vapor passage into the canister part  150  via the evaporation port  151 . The fuel vapor in the canister part  150  is purged to the intake passage via the purge passage due to the intake negative pressure. While the fuel vapor in the canister part  150  is purged, atmospheric air is introduced into the canister part  150 . 
     A part of the pressurized fuel that is ejected from the fuel pump  58  into the fuel passage  133  of the discharge pipe part  96  of the pump case  60  is discharged into the fuel receiving pipe part  71  of the sub-tank body  66  via the leakage passage  178  of the leakage passage forming member  170 . At this time, the leakage amount of the pressurized fuel is restricted by the restriction part  180  of the first cap  174 . The pressurized fuel flows downward through the connection port  183  of the second cap  176  into the extended tube part  190 . Then, the flow direction of the pressurized fuel is changed by about 90 degrees by the direction change wall part  191  such that the pressurized fuel is jetted from the pressurized fuel jet port  193  in a direction toward an inner wall surface of the pipe part  182   a  of the cap part  182  (see arrows in  FIG. 7 ). Because the direction change wall part  191  is formed in substantially a quarter of sphere shape, the flow direction of the pressurized fuel is changed smoothly along the flow path. A recessed arc-shaped wall part, which faces the pressurized fuel jet port  193 , of the pipe part  182   a  may also be referred to herein as a facing wall  182   c.    
     In accordance with the first embodiment, the flow direction of the pressurized fuel is changed by the direction change wall part  191  of the second cap  176  so as to prevent the pressurized fuel from directly impacting the filter member  75 . Thus, a strong impact on the upper surface of the filter member  75  of the fuel filter  67  by the pressurized fuel can be avoided. Accordingly, the deformation of the filter member  75  of the fuel filter  67  caused by the pressurized fuel jetted from the leakage passage  178  can be suppressed. 
     This point will be described. If the direction change wall part  191  of the second cap  176  was not provided, the pressurized fuel would be jetted directly downward from the extended tube part  190  of the second cap  176 . Thus, the pressurized fuel would directly run into and impact the upper surface of the filter member  75 . The pressurized fuel would violently collide with the filter member  75  such that there is a possibility that the upper surface of the filter member  75  could be concavely deformed. In contrast, in accordance with the first embodiment, because the extended tube part  190  is provided with the direction change wall part  191 , the pressurized fuel is prevented from violently running into and impacting the filter member  75 . Thus, a strong impact on the upper surface of the filter member  75  by the pressurized fuel can be avoided, thereby suppressing the deformation of the filter member  75 . 
     The direction change wall part  191  of the second cap  176  changes the flow direction of the pressurized fuel. Therefore, the pressurized fuel is jetted from the pressurized fuel jet port  193  laterally. Accordingly, the direct collision of the pressurized fuel with the upper surface of the filter member  75  of the fuel filter  67  can be avoided. 
     In this embodiment, the direction change wall part  191  and the pressurized fuel jet port  193  are formed at the second cap  176  as one piece. Thus, the structure of the second cap  176  having the direction change wall part  191  and the pressurized fuel port  193  can be simplified, so as to decrease the production cost thereof. 
     The second cap  176  includes the facing wall  182   c  having a recessed arc shape. The second cap  176  faces the pressurized fuel jet port  193 . Thus, the pressurized fuel jetted from the pressurized fuel jet port  193  runs into and impacts the facing wall  182   c  of the second cap  176 . Accordingly, the flow direction of the pressurized fuel can be changed, and the flow speed thereof can be decreased so as to decrease the impact force of the pressurized fuel on the filter member  75 . 
     The leakage amount of the fuel can be restricted by the restriction part  180  formed in the first cap  174 . 
     A second embodiment of the present disclosure substantially corresponds to the first embodiment with some changes. Thus, the changes will be described, and the same components as the first embodiment are annotated with the same reference signs, so as to omit repetitive explanations.  FIG. 11  is a cross-sectional view of a surrounding area around the pressure regulator  62 . As shown in  FIG. 11 , a fuel leading pipe part  195  vertically extending is formed at the sub-tank body  66  of the sub-tank  54 . Internal passages of the fuel leading pipe part  195  and a retaining member  198  form a continuous fuel leading passage  196 . The fuel leading passage  196  is a branch passage branched from the fuel passage  133  for returning the pressurized fuel into the sub-tank  54 . The fuel leading passage  196  may also be referred to herein as the “pressurized fuel return passage.” 
     The pressure regulator  62  is attached to a lower end of the fuel leading passage  196 . The pressure regulator  62  controls the pressure within the fuel leading passage  196  to a predetermined pressure. The pressure regulator  62  ejects excess fuel directly downward from an excess fuel discharge port  62   a . The pressure regulator  62  is normally submerged in the fuel stored in the fuel storing space  79 . The fuel leading pipe part  195  may also be referred to herein as a “leading passage forming member.” 
     The resin-made retaining member  198 , which is configured to prevent detachment of the pressure regulator  62 , is attached to the lower end of the fuel leading passage  196 , for instance by snap-fit. The retaining member  198  is formed in a hollow cylindrical shape with a closed bottom, such that it covers a lower half of the pressure regulator  62  with a predetermined gap formed therebetween. The retaining member  198  includes a direction change wall part  200  having a hollow cylindrical shape with a closed bottom. The direction change wall part  200  extends downward from the center of a bottom part of the retaining member  198 . The closed bottom of the direction change wall part  200  faces the excess fuel discharge port  62   a . A plurality of pressurized fuel jet ports  202  (two of them are illustrated in  FIG. 11 ) are formed in a side wall of the direction change wall part  200 . The flow direction of the pressurized fuel ejected from the excess fuel discharge port  62   a  of the pressure regulator  62  is changed by almost 90 degrees by the bottom wall of the direction change wall part  200 . Then, the pressurized fuel is jetted laterally from the pressurized fuel jet ports  202  (see arrows in  FIG. 11 ). The direction change wall part  200  may also be referred to herein as the “wall member.” 
     In accordance with the second embodiment, the pressurized fuel jetted from the excess fuel discharge port  62   a  of the pressure regulator  62  disposed at the downstream end of the fuel leading passage  196  collides with the direction change wall part  200  of the retaining member  198 . Accordingly, the direct collision of the pressurized fuel with the upper surface of the filter member  75  of the fuel filter  67  can be avoided. 
     This point will be described. If the direction change wall part  200  of the retaining member  198  were to be cut and removed to form an opening, the pressurized fuel would be jetted directly downward from the excess fuel discharge port  62   a . The pressurized fuel would therefore directly run into and impact the upper surface of the filter member  75 . Thus, the pressurized fuel would violently collide with the filter member  75  such that there is a possibility that the upper surface of the filter member  75  could be concavely deformed. In contrast, in accordance with the second embodiment, the retaining member  198  is provided with the direction change wall part  200 . This prevents the pressurized fuel from directly colliding with the upper surface of the filter member  75 , thereby suppressing the deformation of the filter member  75 . 
     Although the technology disclosed herein is described above on the basis of the specific embodiments, it can be carried out in other various embodiments. For example, the technology of this disclosure can be applied to some fuel supply devices other than the fuel supply device  20  for the vehicle, such as an automobile. The wall member may be formed separately from the downstream side passage member or the leading passage forming member. In this case, the pressurized fuel jetted from the pressurized fuel jet port runs into the wall member, so as to change the direction thereof. Although a part of the pipe part  182   a  of the cap part  182  of the second cap  176  functions as the facing wall  182   c  in the embodiment, a dedicated facing wall may be formed at the second cap  176  separately from the pipe part  182   a.    
     Various aspects of the technology are disclosed herein. A first aspect is a fuel supply device for supplying a fuel in a fuel tank to an engine, wherein the fuel supply device includes a fuel pump, a sub-tank for storing the fuel, a pressurized fuel return passage for returning a part of a pressurized fuel discharged from the fuel pump into the sub-tank, a fuel filter disposed at a bottom part of the sub-tank and including a filter member that has a bag-like shape and is configured to filter the fuel to be suctioned into the fuel pump, and a wall member configured to change a flow direction of the pressurized fuel jetted from the pressurized fuel return passage, so as to prevent the pressurized fuel from running into the filter member. 
     In accordance with the first aspect, the flow direction of the pressurized fuel jetted from the pressurized fuel return passage is changed by the wall member, so that the direct collision of the pressurized fuel with the filter member of the fuel filter can be avoided. Accordingly, the deformation of the filter member of the fuel filter caused by the pressurized fuel jetted from the pressurized fuel return passage can be suppressed. 
     A second aspect is the fuel supply device of the first aspect, wherein the pressurized fuel return passage defines a leakage passage configured to leak the part of the pressurized fuel discharged from the fuel pump. The fuel supply device includes a downstream side passage member defining a downstream end of the leakage passage. The wall member is formed at the downstream side passage member. A pressurized fuel jet port configured to jet the pressurized fuel, the flow direction of which has been changed by the wall member, is formed at the downstream side passage member. 
     In accordance with the second aspect, the flow direction of the pressurized fuel, which has passed through the leakage passage, is changed by the wall member of the downstream side passage member, and then the pressurized fuel is jetted from the pressurized fuel jet port. Accordingly, the direct collision of the pressurized fuel with the filter member of the fuel filter can be avoided. 
     A third aspect is the fuel supply device of the second aspect, wherein the wall member and the pressurized fuel jet port are formed at the downstream side passage member as one piece. 
     In accordance with the third aspect, the structure of the downstream side passage member including both the wall member and the pressurized fuel jet port can be simplified, so as to decrease the manufacturing cost thereof. 
     A fourth aspect is the fuel supply device of the second or third aspect, wherein the downstream side passage member includes a facing wall having a recessed arc shape and facing the pressurized fuel jet port. 
     In accordance with the fourth aspect, the pressurized fuel jetted from the pressurized fuel jet port runs into the facing wall of the downstream side passage member. Accordingly, the flow direction of the pressurized fuel can be changed, and the speed thereof can be decreased. 
     A fifth aspect is the fuel supply device of the first or second aspect, wherein the fuel supply device includes an upstream side passage member defining an upstream end of the leakage passage. The upstream side passage member includes a restriction part configured to restrict a fuel leakage amount. 
     In accordance with the fifth aspect, the fuel leakage amount can be restricted by the restriction part formed at the upstream side passage member. 
     A sixth aspect is the fuel supply device of the first aspect, wherein the pressurized fuel return passage defines a fuel leading passage configured to lead the part of the pressurized fuel discharged from the fuel pump. The fuel supply device includes a leading passage forming member defining the fuel leading passage. The leading passage forming member is provided with a pressure regulator configured to control a pressure of the pressurized fuel and to discharge an excess portion of the pressurized fuel. A retaining member configured to prevent detachment of the pressure regulator is attached to the leading passage forming member. The wall member is formed at the retaining member. A pressurized fuel jet port configured to jet the pressurized fuel, the flow direction of which has been changed by the wall member, is formed at the retaining member. 
     In accordance with the sixth aspect, it is able to make the pressurized fuel, which is jetted from the pressure regulator provided at a downstream end of the fuel leading passage, run into the wall member of the retaining member. Accordingly, the direct collision of the pressurized fuel with the filter member of the fuel filter can be avoided.