Patent Publication Number: US-9429118-B2

Title: Fuel pump module

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is based on and claims the benefit of priority of Japanese Patent Application No. 2013-176989, filed on Aug. 28, 2013, the disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure generally relates to a fuel pump module. 
     BACKGROUND INFORMATION 
     Conventionally, a fuel pump module is disposed in a fuel tank with a plurality of fuel tank rooms and a fuel transport unit transports fuel to one tank room from the other. For example, a patent document 1 (i.e., Japanese Patent No.: JP-A-2007-247581) discloses a fuel pump module that includes a fuel pump, a subtank that houses the fuel pump while being housed in a fuel tank, and a jet pump that transports the fuel from the fuel tank to the subtank. 
     The fuel pump module disclosed in the patent document 1 has fuel tank having a first tank room housed inside a second fuel room, thereby making a fuel transport distance of the jet pump relatively short. However, if the first tank room is distant from the second tank room due to vehicle layout and/or the configuration of the fuel pump module, for example, the fuel transport distance of the jet pump may become relatively long. In such case, the fuel may evaporate due to the temperature rise in a communication passage between the first tank room and the second tank room, thereby making it difficult for the jet pump of the fuel pump module in the patent document 1 to transport the fuel from the first tank room and the second tank room. Further, such a configuration may make it difficult for the fuel pump module to discharge the fuel from the fuel tank toward an outside of the fuel tank. 
     SUMMARY 
     It is an object of the present disclosure is to provide a fuel pump module which is capable of discharging a fuel from the fuel tank to an internal-combustion engine when the fuel tank has multiple fuel tank rooms. 
     In an aspect of the present disclosure, the fuel pump supplies fuel to an internal-combustion engine from a fuel tank having a plurality of fuel tank rooms and discharges the fuel from the fuel tank to a combustion chamber of the internal-combustion engine. The fuel pump module includes a first pump discharging the fuel from the fuel tank to the combustion chamber of the internal-combustion engine, a first filter removing foreign substance from the fuel that is discharged from the first pump, and a first supply port disposed at a position between the first filter and the combustion chamber into which the fuel is discharged from the first pump, the first supply port allowing the fuel filtered by the first filter to flow therethrough. The fuel pump module also includes a second pump discharging the fuel from the fuel tank to an air-intake system of the internal-combustion engine, and a second supply port disposed at a position between the second filter and the air-intake system, the second supply port allowing the fuel filtered by the second filter to flow therethrough. Further, the fuel pump module includes a fuel transport unit transporting the fuel to a first fuel tank room that houses the first pump and the second pump from a second fuel tank room, and a communication passage providing fluid communication between the first fuel tank room and the second fuel tank room through which the fuel transported by the fuel transport unit flows. The fuel transport unit causes a swirling flow of the fuel when the first pump or from the second pump discharges the fuel. 
     The fuel pump module of the present disclosure is provided with two fuel pumps, two filters, and two supply ports. The fuel tank which houses the above components has plurality of fuel tank rooms, and the two fuel pumps are housed in the one fuel tank room. For a secure discharge of the fuel, the fuel pump module of the present disclosure transports the fuel from one fuel tank room to the other fuel tank room, i.e., from a tank room that houses no fuel pump to a tank room that houses the two fuel pumps. When the fuel is transported in such manner, the fuel transport unit utilizes the pressure of the discharged fuel from the first or second pump to make a swirling flow of the fuel. In such configuration, even when the fuel evaporates due to a temperature rise of the communication passage formation member, the fuel in the communication passage is pressingly transported in one direction which leads to the one fuel tank room, i.e., is transported to the one fuel tank room having the two fuel pumps. Therefore, the fuel in the fuel tank is collected within a proximity of the two fuel pumps that are housed in the one fuel tank room, which makes the fuel to be securely discharged into the internal-combustion engine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Objects, features, and advantages of the present disclosure will become more apparent from the following detailed description made with reference to the accompanying drawings, in which: 
         FIG. 1  is a block diagram of a system of a fuel pump module in one embodiment of the present disclosure; 
         FIG. 2  is a perspective view of a first module in the fuel pump module in one embodiment of the present disclosure; 
         FIG. 3  is a top view of the first module in the fuel pump module in one embodiment of the present disclosure; 
         FIG. 4  is a sectional view of the first module in the fuel pump module in one embodiment of the present disclosure; 
         FIG. 5  is a perspective view of a second module in the fuel pump module in one embodiment of the present disclosure; 
         FIG. 6  is a top view of the second module in the fuel pump module in one embodiment of the present disclosure; 
         FIG. 7  is a sectional view of the second module in the fuel pump module in one embodiment of the present disclosure; 
         FIG. 8A  is a sectional view of a second jet pump in the fuel pump module in one embodiment of the present disclosure; 
         FIG. 8B  is another sectional view of the second jet pump in the fuel pump module in one embodiment of the present disclosure; 
         FIG. 8C  is yet another sectional view of the second jet pump in the fuel pump module in one embodiment of the present disclosure; 
         FIG. 9A  is a sectional view of a jet pump in a comparative example; and 
         FIG. 9B  is another sectional view of the jet pump in the comparative example. 
     
    
    
     DETAILED DESCRIPTION 
     Hereafter, the embodiment of the present disclosure is described based on the drawings. 
     One Embodiment 
     The block diagram explaining a system of a fuel pump module  1  in one embodiment of the present disclosure is shown in  FIG. 1 . The fuel pump module  1  supplies, to an engine  4 , a fuel stored by a fuel tank  8  which has two “fuel tank rooms”, i.e., a first tank room  201  and a second tank room  301 . The fuel pump module  1  supplies, to either one of a combustion chamber  6  of the engine  4  or an air-intake system  5  which is connected to the engine  4 , the fuel in different pressures according to a drive state of the engine  4 . The fuel pump module  1  is, as shown in  FIG. 1 , comprised of a first module  101  and a second module  102  together with other parts such as transport pipes  91  and  92  etc. by which the first module  101  and the second module  102  are connected for flowing the fuel back and forth between a first tank  2  and a second tank  3 . Further, a white arrow F 1  in  FIG. 1  shows a flow of the fuel. Further, a solid line arrow F 2  in  FIG. 1  shows a flow of a gas. The second tank  3  is equivalent to an “other fuel tank room” in the claims. 
     The first module  101  is disposed in the first tank  2 . The first module  101  pressurizes the fuel in the first tank  2 , and supplies the pressurized fuel to the engine  4 , or transports it to the second tank  3 . The first module  101  comprises a suction filter  13 , a direct injection fuel pump  10  (i.e., hereafter designated as a “DI fuel pump  10 ”), a suction filter  23 , a port injection fuel pump  20  (i.e., hereafter designated as a “PI fuel pump  20 ”), a direct injection filter  30  (i.e., hereafter designated as a “DI filter  30 ”), a first jet pump  35 , a first flange  50 , a primary subtank  7 , and other parts. The suction filter  13  is equivalent to a “first suction filter” in the claims. The DI fuel pump  10  is equivalent to a “first pump” in the claims. The PI fuel pump  20  is equivalent to a “second pump” in the claims. The DI filter  30  is equivalent to a “first filter” in the claims. 
     The suction filter  13  comprises a saccate element part  131 , a cylindrical connection part  132 , etc. The suction filter  13  removes foreign substance from the fuel in the primary subtank  7  by using the element part  131 . The connection part  132  is disposed at a position between the saccate element part  131  and the suction part  12  of the DI fuel pump  10 , and is connected to the suction part  12 . The connection part  132  providing a connection port  133  allows a communication between an inside of the element part  131  and a suction port  121  of the suction part  12  of the DI fuel pump  10 . 
     The DI fuel pump  10  is an electromotive pump disposed in the primary subtank  7  that is housed in the first tank  2 . The DI fuel pump  10  pressurizes the fuel in the primary subtank  7  to 500 kPa, for example, and directly supplies the pressurized fuel to the combustion chamber  6  of the engine  4  via a direct injection supply pipe  15  (i.e., hereafter designated as a “DI supply pipe  15 ”) leading to a direct injection supply port  51  (i.e., hereafter designated as a “DI supply port  51 ”) that is disposed on the first flange  50 . In the fuel pump module  1  in one embodiment, it is configured that an amount of the fuel supplied from the DI fuel pump  10  to the engine  4  is greater than an amount of the fuel supplied from the PI fuel pump  20  to the engine  4 . The DI fuel pump  10  comprises the suction part  12 , a pump part  14 , a motor part  16 , a discharge part  18 , and the like. The DI supply port  51  is equivalent to a “first supply port” in the claims. 
     The suction part  12  is disposed on a filter side (i.e. close to the suction filter  13 ) of the DI fuel pump  10 , and is connected to the pump part  14  of the DI fuel pump  10 . The suction part  12  has the suction port  121 . The suction port  121  allows communication between an inside of the suction filter  13  and an inside of the pump part  14 . The suction port  121  is disposed at an away-from-axis position (i.e., a position that is different from a position of an axis of the DI fuel pump  10 ), and sends the fuel from the primary subtank  7  via the suction filter  13  to the pump part  14 . 
     The pump part  14  comprises an impeller which is not illustrated, a pump case  141  which forms a pump room in which the impeller is rotatably accommodated, together with other parts. The pump room allows communication between the suction port  121  of the suction part  12  and a discharge port  181  of the discharge part  18 . 
     The motor part  16  is a brushless motor which comprises a stator, a rotor, a shaft, and the like, all of which are not illustrated. When an electric power is supplied to a not-illustrated winding which is wound on a cylindrical stator via a wire harness  161  (see  FIG. 2 ) and a power supply terminal  162 , a rotor positioned in an inside of the stator rotates together with the shaft. A rotation torque of the shaft is transmitted to the impeller of the pump part  14 . In such manner, the impeller of the pump part  14  rotates, the fuel in the pump room is pressurized, and the pressurized fuel is sent to the discharge part  18 . 
     The discharge part  18  is disposed on an opposite side of the suction part  12  relative to the pump part  14  and the motor part  16 . The discharge part  18  has the discharge port  181  which allows communication between an inside of the pump part  14  and an inside of the pump case  11 . The fuel pressurized by the pump part  14  is sent to a fuel passage  111  that is formed in an inside of the pump case  11  via the discharge port  181 . 
     The pump case  11  is a cylindrical member having a bottom, which is made of resin. The pump case  11  comprises a bottom part  112 , a side part  113 , a connection part  119 , and the like. The DI fuel pump  10  and the DI filter  30  are housed in an inside of the pump case  11 . 
     The bottom part  112  is formed substantially in a disk shape from resin. A through hole  116  is disposed on the bottom part  112  substantially in parallel with an axis of the DI fuel pump  10 . The through hole  116  accepts a connector to be electrically connected to the power supply terminal  162  of the motor part  16  inserted therein. 
     Referring to  FIG. 4 , the side part  113  has (i) a cylindrical space with a bottom, or a one-end-closed cylinder, with two openings, i.e., an opening  117  in communication with the through hole  116  of the bottom part  112  and an opening  115  that is formed on a filter side that is close to the suction filter  13 , and (ii) a donut shape space, or a ring shape space, that is positioned on a radially-outer portion of the cylindrical space. In the one-end-closed cylinder, the DI fuel pump  10  is housed. The DI fuel pump  10  is housed in the one-end-closed cylinder through the opening  115 . Further, through the opening  117 , a connector that is electrically connected with the power supply terminal  162  is housed. At a position that corresponds to the discharge port  181  of the side part  113 , a connection chamber  114  is formed for communication between the discharge port  181  and the fuel passage  111 . The fuel discharged from the discharge port  181  flows through the connection chamber  114  and is sent into the fuel passage  111 . 
     In the donut shape space of the side part  113 , the DI filter  30  substantially in a cylindrical shape is housed. The DI filter  30  is made of a conductive resin which does not contain carbon, for example, and removes foreign substance from the fuel that is discharged from the discharge port  181 . The fuel flowing through the DI filter  30  is sent into the connection part  119  that is disposed on a radially-outer portion of the pump case  11 . 
     The connection part  119  is disposed on a radially-outer portion of the side part  113 , and houses a pressure regulating valve  153 . The pressure of the fuel sent to the connection part  119  is adjusted to a desired value by the pressure regulating valve  153 . The pressure adjusted fuel is then sent to an outside of the first tank  2  via a supply pipe  182  (see  FIG. 1 ) and the DI supply port  51  that is disposed on the first flange  50 . 
     The suction filter  23  includes a saccate element  231 , a connection part  232  substantially in a cylindrical shape, and the like. The suction filter  23  removes foreign substance from the fuel in the primary subtank  7  by using the element  231 . The connection part  232  is disposed at a position between the element  231  and a suction part  22  of the PI fuel pump  20 , and is connected to the suction part  22 . A connection port  233 , which is provided by the connection part  232 , allows communication between an inside of the element  231  and a suction port  221  which is a part of the suction part  22  of the PI fuel pump  20 . 
     The PI fuel pump  20  is an electromotive pump disposed in the primary subtank  7  of the first tank  2  just like the DI fuel pump  10 . The PI fuel pump  20  pressurizes the fuel in the primary subtank  7  to an arbitrary pressure level between 350 to 500 kPa, for example, and sends the fuel to the second tank  3  via a transport pipe  91  leading to a transport port  52  that is disposed on the first flange  50 , and, at the same time, supplies the pressurized fuel to the first jet pump  35  that is mentioned later. The PI fuel pump  20  comprises the suction part  22 , a pump part  24 , a motor part  26 , a discharge part  28 , and the like. 
     The suction part  22  is disposed on a filter side of the PI fuel pump  20 , close to the suction filter  23 , of the PI fuel pump  20 , and is connected to the pump part  24  of the PI fuel pump  20 . The suction part  22  has the suction port  221 . The suction port  221  allows communication between an inside of the suction filter  23  and an inside of the pump part  24 . The suction port  221  is disposed at an away-from-axis position, i.e., a position that is different from an axis of the PI fuel pump  20 , and sends the fuel from the primary subtank  7  via the suction filter  23  to the pump part  24 . 
     The pump part  24  comprises an impeller which is not illustrated, a pump case  241  which forms a pump room, in which the impeller is rotatably accommodated, together with other parts. The pump part  24  allows communication between the suction port  221  of the suction part  22  and a discharge port  281  of the discharge part  28 . 
     The motor part  26  is a brushless motor which includes a stator, a rotor, a shaft, and the like, all of which are not illustrated. When an electric power is supplied to a not-illustrated winding which is wound on a cylindrical stator via a wire harness  261  (see  FIG. 2 ) and a power supply terminal  262 , a rotor provided in an inside of the stator rotates together with the shaft. A rotation torque of the shaft is transmitted to the impeller of the pump part  24 . In such manner, the impeller of the pump part  24  rotates, the fuel in the pump part  24  is pressurized, and the pressurized fuel is sent to the discharge part  28 . 
     The discharge part  28  is disposed on an opposite side of the suction part  22  relative to the pump part  24  and the motor part  26 . The discharge part  28  has the discharge port  281  which allows communication between an inside of the pump part  24  and an inside of the pump case  21 . The discharge part  28  is connected to a connection part  211  that is formed in an inside of the pump case  21 . The fuel pressurized by the pump part  24  is sent to a connection part  212  through the discharge port  281 . 
     The pump case  21  is a cylindrical member having a bottom, which is made of resin. On one side of the pump case  21  close to the suction filter  23 , an opening  215  is formed. The PI fuel pump  20  is inserted/assembled in an inside of the pump case  21  through the opening  215 . The pump case  21  is equivalent to a “first pump housing” in the claims. 
     The connection part  211  disposed on an opposite side of the pump case  21  relative to the suction filter  23  has a flow passage that branches into two directions. One of the two branches, i.e., a flow passage  212 , communicates with an inside of the first jet pump  35  via a supply pipe  351  (see  FIG. 1  and  FIG. 2 ) having an orifice  291 . The other one of the two branches, i.e., a flow passage  213  houses a non-return valve  29  that regulates a flow of the fuel in one way. The fuel flowing in the other passage  213  is sent to an outside of the first tank  2  via a transport pipe  292  (see  FIG. 1  and  FIG. 2 ) and the transport port  52  disposed on the first flange  50 . 
     At a position on an opposite side of the pump case  21  opposite to the suction filter  23 , a through hole  214  is formed, which is a different position from the connection part  211 . Through the through hole  214 , a connector that is electrically connected with a power supply terminal  262  of the motor part  26  is inserted/installed. 
     As shown in  FIG. 2 , the first jet pump  35  is disposed on the other end of the module  101  relative to the first flange  50 , at a radially-outer portion of the primary subtank  7 . The first jet pump  35  introduces the fuel from the first tank room  201  to the primary subtank  7  with a help of the pressure of the discharged fuel from the PI fuel pump  20 . In  FIG. 2  and  FIG. 4 , an upward direction with respect to the drawing is designated a “sky” side, and a downward direction with respect to the drawing is designated as an “earth” side. 
     A sender gauge  38  is disposed at a radially-outer portion of the primary subtank  7 , as shown in  FIGS. 2 and 3 . The sender gauge  38  is connected with a float  381  via an arm  382 . When the float  381  moves according to a change of a fuel level, the arm  382  rotates, and the fuel level is detected by the sender gauge  38  based on a detection of the rotation amount of the arm  381 . The sender gauge  38  outputs a fuel-level detection signal via a wire harness  383  and the first flange  50  to a non-illustrated electrical control unit (i.e., hereafter an “ECU”) which is disposed externally to the module  101 . 
     The first flange  50  is formed in a disk shape, and it is put on an opening  200  of the first tank  2 , which is “one opening” and serves as a cover of the opening  200  (see  FIG. 1 ). On the first flange  50 , a transport port  53  through which the fuel flows from the second tank  3  to the primary subtank  7  and a reflux port  54  which allows a reflux of the fuel flowing from a pressure regulating valve  253  disposed in a port injection supply pipe  25  (i.e., hereafter a “Pl supply pipe  253 ”) to be mentioned later back to the primary subtank  7  are provided, besides the DI supply port  51  and the transport port  52 . Further, on the first flange  50 , an external connector  551  which is electrically connected to the wire harnesses  161  and  261  and supplies an electric power to the DI fuel pump  10  and the PI fuel pump  20  and an external connector  552  which outputs, to an outside of the module  1  via the wire harness  383 , a signal of the fuel level which is detected by the sender gauge  38  are disposed. 
     The primary subtank  7  is formed in a bottom-closed cylinder shape and is made from resin. The primary subtank  7  houses the DI fuel pump  10 , the PI fuel pump  20 , and the like, as mentioned above, and, on a radially-outer portion of the primary subtank  7 , the first jet pump  35  and the sender gauge  38  are disposed. 
     As shown in  FIG. 2 , the first flange  50  and the primary subtank  7  are connected by two shafts  17  so that a relative position of the two (i.e., the flange  50  and the primary subtank  7 ) is changeable. On a radially-outer portion of the shaft  17 , a spring  171  biasing the first flange  50  and the primary subtank  7  away from each other is disposed. Thereby, the primary subtank  7  is pressed against a bottom of the first tank  2 . 
     The second module  102  is disposed in the second tank  3 . The second module  102  removes foreign substance from the fuel that is sent from the first tank  2  and supplies the fuel to the engine  4 , and/or transports the fuel in the second tank  3  to the first tank  2  with a help of the pressure of the fuel that is sent from the first tank  2 . The second module  102  is provided with a port injection filter  40  (i.e., hereafter a “PI filter  40 ”), a filter case  41 , a residual pressure maintenance valve  47 , a second jet pump  45 , a second flange  60 , and the like. The PI filter  40  is equivalent to a “second filter” in the claims. The filter case  41  is equivalent to a “housing member” in the claims. The second jet pump  45  is equivalent to a “fuel transport unit”. Further, in  FIG. 5  and  FIG. 7 , an upward direction with respect to the drawing is designated as a “sky” side, and a down upward direction with respect to the drawing is designated as an “earth side”. 
     The PI filter  40  is substantially formed in a cylinder shape, and is housed in the filter case  41  that has the same shape as the pump case  11  of the DI fuel pump  10 . More practically, the PI filter  40  is housed in a donut shape space, which is in an inside of the filter case  41 . The PI filter  40  is, for example, made from a conductive material which does not contain carbon or the like. The PI filter  40  removes foreign substance from the fuel that is sent from the first tank  2 . 
     The filter case  41  is supported by an outer bracket  43  through a ring-shape inner bracket  42  that has a ring shape. A column shape space substantially at the center of the filter case  41 , a ground bracket  44  is housed as shown in  FIG. 7 . 
     The filter case  41  has, disposed thereon, a transport pipe  412  and a transport port  413 , which introduce the fuel from the first tank  2  via a transport port  62  on the second flange  60  into an inside of the case  41 . The fuel introduced into the filter case  41  through the transport port  413  passes a fuel passage  414  and the PI filter  40  in an inside of the filter case  41 . The fuel flowing through the PI filter  40  is supplied to the air-intake system  5  of the engine  4  via a supply pipe  282 , a port injection supply port  61  (i.e., hereafter a “PI supply port  61 ”) disposed on the second flange  60 , and the PI supply pipe  25  connected to the PI supply port  61 . Further, a part of the fuel which passes the 
     PI filter  40  is introduced into the residual pressure maintenance valve  47  that is housed in a radially-outer portion of the filter case  41 . The PI supply port  61  is equivalent to a “second supply port” in the claims. 
     The residual pressure maintenance valve  47  is housed in a connection part  411  disposed on a radially-outer portion of the filter case  41 , as shown in  FIG. 7 . The residual pressure maintenance valve  47  serving as a “pressure regulating valve,” maintains a pressure of the fuel in an inside of the PI filter  40 , which is disposed on an upstream side of the valve  47 , at a certain level such as 320 kPa, for example, and prevents the fuel in the PI filter  40  to evaporate. The fuel flowing through the residual pressure maintenance valve  47  is sent to the second jet pump  45  through a supply pipe  451 . 
     The second jet pump  45  is disposed on an opposite side of an outer bracket  43  opposite to the second flange  60 , (i.e., at a lower position with respect to gravity) of the outer bracket  43  between (i) a secondary subtank  46  serving as a “supporting member” and (ii) the outer bracket  43 . The second jet pump  45  comprises a jet part  452 , a suction part  453 , and the like. 
     Further, the filter case  41  houses at least one of the first pump, the second pump, the first filter, or the second filter. The secondary subtank  46  is connected to the filter case  41  at a position that is lower (i.e., a lower position with respect to gravity) than the filter case  41 . The second jet pump  45  is disposed at a position between the filter case  41  and the secondary subtank  46 . 
     The jet part  452  comprises a supply part  454 , a throat part  455 , and the like. The supply part  454  is substantially in a cylindrical shape. The supply part  454  is connected to a supply pipe  451 , and the fuel that has passed the residual pressure maintenance valve  47  is supplied to the supply part  454 . The throat part  455  is connected to the supply part  454 , and is formed to have a gradually-decreasing inner diameter as the throat part  455  comes afar from the supply part  454 . The throat part  455  is inserted into the suction part  453 , with its opening that is opposite to the supply part  454  positioned in a suction room  456  of the suction part  453 . On one side of the supply part  454  which is close to the throat part  455 , a swirling flow formation member  457  is disposed. 
     The swirling flow formation member  457  is formed in an inner diameter decreasing shape from one side to the other, i.e., from a supply part  454  side to a throat part  455  side. In other words, the swirling flow formation member  457  has a gradually-decreasing inner diameter along the flow direction of the fuel inside of the fuel transport unit. One end of the swirling flow formation member  457  close to the supply part  454  has, as shown in  FIG. 8B , two half circle openings  458 . The openings  458  may be formed symmetrically with respect to a center axis (φ) of the jet part  452 . The other end of the swirling flow formation member  457  close to the throat part  455  also has, as shown in  FIG. 8C , has two half circle openings  459  whose opening area size is smaller than the opening  458 . The openings  459  are positioned point-symmetrically on the center axis φ of the jet part  452 . In other words, the openings  459  may be formed symmetrically with respect to the center axis (φ) of a flow of the fuel inside of the jet part  452 . The fuel passing through the opening  459  flows in a direction that is non-parallel with respect to the center axis φ of the jet part  452 , which is a flow direction of the fuel in the jet pump  45 . The opening  458  and opening  459  are in communication with each other, and the swirling flow formation member  457  has two passages respectively having a slope  450 . 
     The suction part  453  is formed substantially in a cylindrical shape, and provides the suction room  456  in an inside thereof into which the fuel in secondary subtank  46  is suctioned. The suction part  453  is in connection with a transport pipe  461 , and the suction room  456  is, via the transport pipe  461 , in communication with a transport port  63  provided on the second flange  60 . The opening  459  is provided on an outer wall of the suction part  453 , for the communication between the suction room  456  and an inside of the secondary subtank  46 . 
     The second jet pump  45  is a so-called press-down type jet pump, and suctions the fuel from the second tank  3  with a help of the pressure of the fuel supplied from the residual pressure maintenance valve  47 . As shown in  FIG. 8A , the fuel passing through the swirling flow formation member  457  in the jet part  452  forms a swirling flow F 3  that swirls substantially around the center axis φ (i.e., a two-dot chain line arrow of  FIG. 8A ). The swirling flow F 3  is injected into the suction room  456  of the suction part  453  at a high speed from the throat part  455  that has a gradually-decreasing inner diameter (i.e., a two-dot chain line arrow F 4  of  FIG. 8A ). At such time, the fuel of the suction room  456  flows into the transport pipe  461  accompanied and induced by the injected fuel from the throat part  455 . The fuel flowing through the transport pipe  461  is sent to an outside of the second tank  3  through the transport port  63  on the second flange  60 . 
     The sender gauge  48  is provided on a radially-outer portion of the filter case  41 , as shown in  FIG. 5 . The sender gauge  48  is connected with a float  481  via an arm  482 . When the float  481  moves according to a change of a fuel level, the arm  482  rotates, and the fuel level is detected by the sender gauge  48  by detecting a rotational amount of the arm  482 . The sender gauge  48  outputs a fuel-level detection signal via the second flange  60  to an external ECU that is provided on the outside of the second module  102 . 
     The second flange  60  is formed in a disk shape, and covers an opening  300  that serves as a “second opening”. The second flange  60  has the PI supply port  61  and the transport ports  62  and  63  disposed thereon. The second flange  60  also has an external connector  651  which outputs a signal which represents the fuel level detected by the sender gauge via a wire harness  483  to an outside of the second module  102 . 
     In the fuel pump module  1 , the transport port  52  on the first flange  50  and the transport port  62  on the second flange  60  are connected with each other by the transport pipe  91  in which the fuel flows from the first tank  2  to the second tank  3 . Further, the transport port  53  of the first flange  50  and the transport port  63  of the second flange  60  are connected with each other by the transport pipe  92  that serves as a “communication passage formation member” in which the fuel flows from the second tank  3  to the first tank  2 . By such connections, the fuel is transported from the second tank  3  to the first tank  2  in which two fuel pumps are provided, and the fuel is securely supplied from the first tank  2  and the second tank  3  to the engine  4 . 
     The second flange  60  and the filter case  41  are connected with two shafts  27  as shown in  FIG. 5 . A spring  271  is provided on a radially-outer portion of the shafts  27 , with which the filter case  41  is biased away from the second flange  60 . Thereby, the filter case  41  is pressed away from to the second flange  60  and is pressed against the bottom of the second tank  3 . 
     Next, the operation of the fuel pump module  1  is described. 
     When an electric power is supplied to the DI fuel pump  10  and to the PI fuel pump  20  via the external connector  551  from an outside of the module  1 , the DI fuel pump and the PI fuel pump are driven, and the fuel in the primary subtank  7  is suctioned via the suction filters  13  and  23  and pressurized. 
     Foreign substance is removed from the fuel by the DI filter  30  in the DI fuel pump  10 , when the fuel discharged from the pump part  14  is filtered by the filer  30  in the pump case  11 . After the removal of the foreign substance from the fuel by the DI filter  30 , the pressure of the fuel is adjusted to a suitable value by the pressure regulating valve  153 , and the pressure adjusted fuel is directly supplied to the combustion chamber  6  of the engine  4  through the supply pipe  182 , the DI supply port  51  on the first flange  50 , and the DI supply pipe  15 . 
     On the other hand, in the PI fuel pump  20 , the fuel discharged from the pump part  24  is in part transported into the second tank  3  through the transport pipe  492 , the transport port  52  on the first flange  50 , the transport pipe  91 , the transport port  62  on the second flange  60 , and the transport pipe  412 , after passing through the non-return valve  49 . Further, the fuel from the pump part  24  is in part supplied to the first jet pump  35  through the supply pipe  351 . In the first jet pump  35 , the fuel is introduced from the first tank  2  into the primary subtank  7  with a help of the pressure of the supplied fuel. 
     The pressurized fuel which is transported from the first tank  2  through transport pipe  91  to the second tank  3  passes through the PI filter  40  for the removal of a foreign substance. The fuel from the PI filter  40  is in part supplied to the air-intake system  5  of the engine  4  through the supply pipe  282 , the PI supply port  61  on the second flange  60 , and the PI supply pipe  25 . At such time, the pressure of the fuel passing through the PI supply pipe  25  is adjusted by the pressure regulating valve  253  according to the pressure of an intake air introduced via the vent pipe  255  which is open to the air-intake system  5 , for example. After the pressure adjustment, the surplus fuel which will no longer be supplied to the air-intake system  5  is returned to the first tank  2  via the return pipe  254  and the reflux opening  54  on the first flange  50 . 
     Further, a part of the fuel passing through the PI filter  40  is supplied to the second jet pump  45  through the residual pressure maintenance valve  47  and the supply pipe  451 . The second jet pump  45  sends the fuel from the second tank  3  to the primary subtank  7  via the transport pipe  461 , the transport port  63  on the second flange  60 , the transport pipe  92 , and the transport port  53  on the first flange  50  with a help of the pressure of the supplied fuel. Thereby, the fuel of the second tank room  301  that serves as a “one fuel tank room” is pressurized by the DI fuel pump and the PI fuel pump in the first tank  2 , and is supplied to the engine  4 . 
     In the fuel pump module  1  in one embodiment, the second jet pump  45  that transports the fuel in the second tank room  301  from the second tank  3  to the first tank  2  forms a swirling flow in an inside thereof. In the following, the effect of the swirling flow formed in the jet pump is described based on  FIGS. 8A /B/C and  9 A/B. 
     The sectional views of the jet pump in  FIGS. 9A /B are provided as a comparative example, in which no swirling flow formation member is provided. When an inside of the transport pipe  961  connected to a downstream side of a jet pump  95  and an inside of the suction room  956  are filled with fuel as shown in  FIG. 9A , the fuel injected from a jet part  952  of the jet pump  95  diffuses due to the resistance of the fuel in the suction room  956 , which is shown by two double-dotted chain line arrows F 5 . Thereby, the fuel injected from the jet part  952  is transported into the transport pipe  961  while inducing the fuel in the suction room  956  to be transported at the same time. However, when, for example, the fuel in the second tank room  301  decreases to a low level and temperature of the second tank room  301  rises, the fuel in an inside of the transport pipe  961  and in the suction room  956  is thinned and evaporates, thereby not causing the resistance to the fuel injected from the jet part  952 . In such case, the fuel injected from the jet part  952  flows in a linear shape as shown by a two-dot chain line arrow F 6  of  FIG. 9B  without diffusion/spreading, thereby returning back to the secondary subtank  96  through the opening  959  from the suction room  956 , which may make it impossible for the jet pump  95  to transport the fuel to the first tank that is disposed separately from the second tank. 
     The fuel pump module  1  in one embodiment forms, as shown in  FIG. 8A , a swirling flow of the fuel by the swirling flow formation member  457  in the jet part  452  (i.e., a two-point chain line arrow F 3  in  FIG. 8A ), causing the fuel injected from the throat part  455  to be diffused in the suction room  456 . Thereby, the fuel is transported to the first tank  2  via the transport pipe  461 , without being influenced by the state of the fuel in the suction room  456  or the transport pipe  461 . Therefore, in the fuel pump module  1 , the two fuel pumps securely discharge the fuel from the fuel tank  8  to the engine  4 . 
     Further, the second jet pump  45  is disposed at a position in between the secondary subtank  46  and the outer bracket  43 . Thereby, when the outer bracket  43  is pressed against the bottom of the second tank  3  with the spring  271 , the secondary subtank  46  abuts on the bottom of the second tank  3 , and the biasing force of the spring  271  is not directly applied to the second jet pump  45 . Therefore, breakage of the second jet pump  45  is prevented and the fuel in the second tank room  301  is securely discharged to the engine  4 . 
     The swirling flow formation member  457  of the second jet pump  45  has two openings  459  formed on the end close to the throat part  455 . The plurality of flows of the fuel passing through the opening  459  flow in the non-parallel direction with respect to the center axis (φ) of the jet part  452 , and the swirling flow is caused as a combination of the plurality of flows. In the jet pump of the fuel pump module in the patent document 1 mentioned above, the swirling flow is formed by the fuel that flows along a non-aligned direction relative to the center axis of a swirl room, thereby the pressure of the fuel is mainly applied to a tangential direction of the swirling flow with little or no effect in the axial direction of the swirl. Therefore, a jet nozzle formed in parallel with the axial direction of a swirl room cannot inject the fuel at high speed. Further, when plurality of fuel tank rooms are provided at separate positions due to the restriction of the fuel tank layout in the vehicle, the fuel pump module in the patent document 1 may be not capable of stably transporting the fuel from one fuel tank room to the other because of the above-described jet nozzle that cannot inject the fuel at high speed. On the other hand, the fuel pump module  1  in one embodiment of the present disclosure applies the pressure of the fuel that is discharged from the PI fuel pump  20  in the axial direction of the swirling flow, thereby effectively utilizing the pressure of the discharged fuel from the PI fuel pump  20 . In such manner, the pressure of the fuel injected from the second jet pump  45  becomes relatively high, thereby enabling a secure transportation of the fuel from the distantly-positioned second tank room  301  to the first tank room  201 . 
     Further, the swirling flow formation member  457  of the second jet pump  45  has its inner diameter gradually decreasing from a supply part  454  side toward a throat part  455  side. Thereby, the speed of the fuel flowing through the throat part  455  is relatively high, which effectively causes the suction of the fuel at the suction part  453 . 
     Other Embodiments 
     (a) According to the above-mentioned embodiment, the fuel tank is described as a split-type fuel tank that has two tanks, i.e., the first tank and the second tank, in communication with each other. However, the fuel tank may have other configuration, such as a saddle-type fuel tank in which the bottom part of the fuel tank room where the fuel is stored is split into two. The number of the fuel tank rooms is not limited to two, but may be three or more. 
     (b) According to the above-mentioned embodiment, the fuel pump module is described as having two fuel pumps. However, the number of the fuel pumps in the fuel pump module is not limited to two. The number of the fuel pumps may be three or more, may be only one. The same applies to the filter, the supply port, and the flange. 
     (c) According to the above-mentioned embodiment, the swirling flow formation member is described that it has two half circle openings at the end close to the supply part, has two half circle openings at the end close to the suction part, and has two passages which allow communication between the supply part side openings and the suction part side openings. However, the shape of the swirling flow formation member is not limited to such shape. That is, as long as it is capable of forming the swirling flow, the member may have any shape. 
     (d) According to the above-mentioned embodiment, the second jet pump sends the fuel from the second tank room to the first tank room with the help of the pressure of the fuel that is discharged from the PI fuel pump. However, the second jet pump serving as a “fuel transport unit” may be driven in other manners. 
     (e) According to the above-mentioned embodiment, the second jet pump is disposed at a “bound” position in between the outer bracket and the secondary subtank. However, the second jet pump serving as a “fuel transport unit” may be disposed in other manners. 
     As mentioned above, the fuel pump module may be variably implemented as long as the gist of the fuel pump module pertains to the inventive feature of the present disclosure.