Patent Publication Number: US-2016230987-A1

Title: Fuel supply apparatus and fuel supply unit

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2015-023033, filed Feb. 9, 2015, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a fuel supply apparatus and a fuel supply unit for supply of gas fuel. 
     2. Related Art 
     In a fuel supply apparatus, during operation for supply of gas fuel, an abrupt change in cross-sectional area of a flow passage may cause separation of flow or stream of the gas fuel, thereby generating gas flow sound (noise). To avoid such defects, there has been proposed a fuel supply apparatus configured to reduce leakage of the noise to the outside. 
     One example of the fuel supply apparatus of the above type is configured such that a nozzle member is fixedly provided in a leading end portion of a valve housing internally including a gas fuel passage and accommodating a valve element, and the nozzle member is provided with a valve seat member facing the gas fuel passage, a valve hole formed through a center portion of the valve seat member and to be opened and closed by cooperation of the valve element and the valve seat member, a first throttle hole communicated with an outlet of the valve hole, and a nozzle hole communicated with an outlet of the first throttle hole through a first annular step portion and having a larger diameter than the first throttle hole. The nozzle hole is provided with a second throttle hole communicated with a second annular step portion opposed to the first annular step portion and having a smaller diameter than the nozzle hole. The second annular step portion and the second throttle hole are formed in an annular member that is separate from the nozzle member and connected with the leading end portion of the nozzle member. 
     In the thus configured fuel supply apparatus, even if gas flow sound (noise) occurs due to the separation of gas fuel flow in the nozzle hole, the second annular step portion and the second throttle hole provided in the leading end portion of the nozzle member can reduce leakage of the noise to the outside (see Patent Document 1). 
     RELATED ART DOCUMENTS 
     Patent Documents 
     Patent Document 1: JP-A-2014-55569 
     SUMMARY OF INVENTION 
     Problems to be Solved by the Invention 
     In the foregoing fuel supply apparatus arranged such that the second annular step portion and the second throttle hole are provided in the leading end portion of the nozzle member, even if gas flow sound (noise) occurs due to separation of gas fuel flow in the nozzle hole, outside leakage of such noise is prevented. However, the flow separation leading to the generation of noise takes place. Thus, the generation itself of the gas flow sound could not be reduced. This may cause leakage of the gas flow sound to the outside. 
     The present invention has been made in view of the circumstances to solve the above problems and has a purpose to provide a fuel supply apparatus and a fuel supply unit capable of suppressing the generation of separation of gas fuel flow to reduce gas flow sound. 
     Means of Solving the Problems 
     To achieve the above purpose, one aspect of the invention provides a fuel supply apparatus having a discharge hole and configured to adjust a flow rate of fuel gas and inject and supply the fuel gas through the discharge hole, the apparatus comprising: an open portion formed with a larger diameter than the discharge hole and communicated with a downstream end of the discharge hole; and a separation suppressing member configured to suppress generation of separation of flow of the gas fuel when the gas fuel flows out from the discharge hole into the open portion, and wherein the separation suppressing member is placed in one of the open portion and the discharge hole. 
     In the fuel supply apparatus configured as above, the separation suppressing member placed in the open portion or the discharge hole can decelerate the gas fuel in flowing out from the discharge hole into the open portion, thereby suppressing the generation of separation of the gas fuel flow. This configuration can reduce gas flow sound which may be caused by the separation of gas fuel flow. 
     To achieve the above purpose, another aspect of the invention provides a fuel supply unit including at least one fuel injection apparatus configured to adjust a flow rate of gas fuel and inject the gas fuel and an outflow passage in which the gas fuel injected from the fuel injection apparatus is to be discharged, wherein the fuel supply unit comprises a flow restricting member configured to forcibly direct the gas fuel discharged from a discharge hole of the fuel injection apparatus into the outflow passage to flow in a radial direction of the discharge hole. 
     In the fuel supply unit configured as above, the flow restricting member directs a gas fuel discharged from the discharge hole of the fuel injection apparatus into the outflow passage to flow in a radial direction. Thus, the gas fuel is dispersed in the outflow passage and also decelerated. Accordingly, the separation of gas fuel flow can be prevented. This makes it possible to reduce the gas flow sound resulting from the separation of gas fuel flow. 
     Effects of the Invention 
     The fuel supply apparatus and the fuel supply unit according to the present invention can suppress the generation of separation of gas fuel flow and hence reduce the gas flow sound. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view of a fuel injection apparatus in a first embodiment; 
         FIG. 2  is an enlarged sectional view of a valve seat member and its surroundings; 
         FIG. 3  is a view of a first modified example; 
         FIG. 4  is a view of a second modified example; 
         FIG. 5  is a view of a third modified example; 
         FIG. 6  is a view of a fourth modified example; 
         FIG. 7  is a sectional view of a fuel supply unit in a second embodiment; 
         FIG. 8  is an enlarged sectional view of a leading end and its surrounding of a fuel injection apparatus in a fuel supply unit; and 
         FIG. 9  is another enlarged sectional view of the leading end and its surrounding of the fuel injection apparatus in the fuel supply unit. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A detailed description of preferred embodiments of a fuel supply apparatus and a fuel supply unit embodying the present invention will now be given referring to the accompanying drawings. The present embodiment shows an example that the present invention is applied to supply a gas fuel (e.g., hydrogen) to a fuel cell (not shown). 
     First Embodiment 
     A schematic entire configuration of a fuel injection apparatus (an injector) of a first embodiment which is one example of a fuel supply apparatus of the present invention will be explained referring to  FIGS. 1 and 2 .  FIG. 1  is a sectional view of the fuel injection apparatus in the present embodiment.  FIG. 2  is an enlarged sectional view of a valve seat member and its surrounding. As shown in  FIG. 1 , the fuel injection apparatus  1  includes a main body  10 , a valve element  12 , a valve seat member  14 , a compression spring  16 , a separation suppressing member  80 , and others. 
     The main body  10  includes a housing  24 , a stator core  26 , a casing  28 , an electromagnetic coil  30 , and others. This main body  10  accommodates the valve element  12 , the valve seat member  14 , the compression spring  16 , and others. In the main body  10 , there is formed a fuel passage  34  in which a gas fuel will flow. 
     The housing  24  is configured to surround a part of the stator core  26  and a part of the casing  28 . The housing  24  is made of resin in which the electromagnetic coil  30  is embedded. This electromagnetic coil  30  is placed in a position surrounding the stator core  26 . The electromagnetic coil  30  is a drive part to drive the valve element  12  to be brought in contact with and separated from the valve seat member  14 . The housing  24  is further provided with a connector part  38  provided therein with a plurality of terminal pins  36 . These terminal pins  36  are electrically connected to the electromagnetic coil  30 . 
     The stator core  26  is placed on an opposite side to the valve seat member  14  with respect to the valve element  12 . The stator core  26  has a nearly cylindrical shape (including an exact circular cylindrical shape, an elliptic shape, etc.) and is formed at its center with a through hole  26   a.  This through hole  26   a  constitutes an upstream part of the fuel passage  34 . An upstream end (an upper end in  FIG. 1 ) of the stator core  26  can be connected to an external fuel supply section (not shown). The stator core  26  is made of soft magnetic material (e.g., electromagnetic stainless steel). It is to be noted that the gas fuel in the fuel passage  34  flows by passing through a filter member  20  for removing foreign substances contained in the fuel. 
     The casing  28  is placed in a position on a downstream side (a lower side in  FIG. 1 ) of the stator core  26  in a flowing direction of gas fuel. The casing  28  has a nearly cylindrical shape and is formed at its center with a through hole  28   a.  The casing  28  is made of soft magnetic material (e.g., electromagnetic stainless steel). The casing  28  accommodates, in the through hole  28   a,  the valve element  12  and the valve seat member  14 . 
     The valve element  12  is placed in a position on an upstream side (an upper side in  FIG. 1 ) of the valve seat member  14  in the gas fuel flowing direction. The valve element  12  is made of soft magnetic material (e.g., electromagnetic stainless steel). This valve element  12  is urged by the compression spring  16  toward the valve seat member  14 . 
     The valve element  12  has a closed-bottom cylindrical shape (a nearly cylindrical shape), namely, is formed in a shape having a cylindrical portion and a closed bottom portion. To be concrete, the valve element  12  includes a cylindrical portion  40  having a nearly cylindrical shape corresponding to the cylindrical portion of the closed-bottom cylindrical shape and a seal portion  42  having a nearly disc-like shape corresponding to the closed-bottom portion of the closed-bottom cylindrical shape, and others. The cylindrical portion  40  is formed with a flow passage  44  which is part of the fuel passage  34 . The seal portion  42  is adapted to come into and out of contact with the valve seat member  14  and is made of rubber, resin, and others. 
     The valve seat member  14  is placed in a position on a downstream side (a lower side in  FIG. 1 ) of the valve element  12  in the gas fuel flowing direction within the through hole  28   a  of the casing  28 . The valve seat member  14  is a component with which the valve element  12  comes into and out of contact. The valve seat member  14  is fixed to the casing  28  selectively by press-fitting in the casing  28 , by welding to the casing  28  over the whole circumference, or by both press-fitting and welding. 
     The valve seat member  14  includes a seat portion  56  and a peripheral wall portion  58 . The seat portion  56  is formed in a disc-like shape. This seat portion  56  includes a seat surface  60 , a discharge hole  62 , and others. The seat surface  60  is a surface located on a side of the seat portion  56  facing the valve element  12 . With this seat surface  60 , the seal portion  42  of the valve element  12  will be brought into or out of contact. The discharge hole  62  is a through hole formed to axially penetrate through a radially central portion of the seat portion  56 . The discharge hole  62  is a flow passage of gas fuel. The peripheral wall portion  58  is formed in a cylindrical shape extending from the seat portion  56  along the axial direction of the valve element  12  toward an opposite side from the valve element  12 . Accordingly, the peripheral wall portion  58  is internally provided with an open portion  59  with a larger diameter than a diameter of the discharge hole  62 . This open portion  59  is communicated with a lower end of the discharge hole  62 . 
     Further, the open portion  59  is provided therein with a separation suppressing member  80  as shown in  FIG. 2 . This separation suppressing member  80  is fixed in the open portion  59  selectively by press-fitting into, welding to, or caulking to the open portion  59 . The separation suppressing member  80  serves to suppress the gas fuel flow or stream from getting separated in flowing out into the open portion  59  through the discharge hole  62 . In the present embodiment, the separation suppressing member  80  is made of a porous body such as a sintered filter and is filled in the open portion  59 . 
     In the present embodiment, the separation suppressing member  80  is filled almost over the entire area within the open portion  59 , but the separation suppressing member  80  is not necessarily fixed all over the entire region and instead may be filled partly in the open portion  59 . In the case of using such a partly filled separation suppressing member  80 , it has to be placed in at least an area communicated with the discharge hole  62  (an uppermost side in the open portion  59 ). 
     In the present embodiment, furthermore, the separation suppressing member  80  is made of a porous body. As an alternative, the separation suppressing member  80  may be made of a mesh body. In the case of using such a mesh separation suppressing member  80 , at least the outer peripheral portion of this separation suppressing member  80  has only to be made of a mesh material (i.e., a basket or cage shaped mesh body). This separation suppressing member  80  may also be further provided with a mesh body inside the mesh outer peripheral portion. As another alternative, the separation suppressing member  80  may be made of a plurality of mesh bodies overlapping one on another. In this case of using the overlapping mesh bodies, these mesh bodies may be different in mesh size. 
     Next, operations (actions) of the fuel injection apparatus  1  will be explained. While the electromagnetic coil  30  is not supplied with power through the terminal pins  36  of the connector part  38 , that is, during valve closing, the seal portion  42  of the valve element  12  is held in contact with the seat surface  60  of the valve seat member  14  by the urging force of the compression spring  16  as shown in  FIG. 1 . Thus, the discharge hole  62  of the valve seat member  14  is shut off from the fuel passage  34 . Accordingly, the gas fuel is not allowed to discharge out of the fuel injection apparatus  1  through the discharge hole  62 . 
     On the other hand, while the electromagnetic coil  30  is supplied with power, or energized, through the terminal pins  36  of the connector part  38 , that is, during valve opening, the electromagnetic coil  30  generates magnetic fields, thereby exciting the valve element  12  and the stator core  26 . Then the valve element  12  and the stator core  26  attract each other, so that the valve element  12  moves toward the stator core  26 . Specifically, the seal portion  42  of the valve element  12  is separated from the seat surface  60  of the valve seat member  14 . Accordingly, the discharge hole  62  of the valve seat member  14  gets communicated with the fuel passage  34 . This allows the gas fuel flowing in the fuel passage  34  to flow in the discharge hole  62  and therefrom flow to the outside of the fuel injection apparatus  1 . 
     At that time, since the passage cross-sectional area abruptly changes from the discharge hole  62  to the open portion  59 , the gas fuel flow or stream may be separated, leading to generation of gas flow sound (noise). In the fuel injection apparatus  1 , however, the gas fuel discharged from the discharge hole  62  flows in the separation suppressing member  80  before acceleration and impinges on the porous body (or mesh body). Accordingly, the gas fuel is decelerated and also dispersed, so that separation of the gas fuel flow in the open portion  59  can be reliably suppressed. This can surely reduce the gas flow sound resulting from the separation of gas fuel flow. 
     Herein, modified examples or variations of the first embodiment will be explained referring to  FIGS. 3 to 6 .  FIG. 3  is a view of a first modified example,  FIG. 4  is a view of a second modified example,  FIG. 5  is a view of a third modified example, and  FIG. 6  is a view of a fourth modified example. In these modified examples, similar or identical parts to those in the first embodiment are assigned with the same reference signs as those in the first embodiment and their details are not repeatedly explained. Thus the following explanation is given with a focus on differences from the first embodiment. 
     In the first modified example, as shown in  FIG. 3 , a separation suppressing member  80   a  placed in the open portion  59  is designed such that a downstream-side end face  81  is spherical. The thus configured separation suppressing member  80   a  can disperse gas fuel flowing out of the separation suppressing member  80   a.  According to the first modified example, therefore, the separation of the gas fuel flow can be further inhibited and thus the gas flow sound resulting from the separation of gas fuel flow can be further reduced. 
     In  FIG. 3 , a spherical portion (the downstream-side end face  81 ) of the separation suppressing member  80   a  spherically protrudes downward from the open portion  59 . As an alternative, the spherical portion may be spherically recessed upward in the open portion  59 . 
     In the second modified example, as shown in  FIG. 4 , a separation suppressing member  80   b  is placed in the discharge hole  62 , not in the open portion  59 . This configuration can decelerate the fuel gas in the discharge hole  62 . Further, The separation suppressing member  80   b  is also designed such that a downstream-side end face  81  is spherical as in the first modified example. Accordingly, the gas fuel flowing out of the separation suppressing member  80   b  (i.e., the discharge hole  62 ) can be dispersed in the open portion  59 . In the second modified example, consequently, the separation of the gas fuel flow in the open portion  59  can also be suppressed and thus the gas flow sound resulting from the separation of gas fuel flow can be further reduced. 
     In the third modified example, as shown in  FIG. 5 , a separation suppressing member  80   c  is placed so as to partially protrude from the open portion  59  and a blocking plate  82  is provided on a downstream-side end of the separation suppressing member  80   c.  The blocking plate  82  serves to block outflow of gas fuel from the downstream-side end face of the separation suppressing member  80   c.  The gas fuel having passed through the separation suppressing member  80   c  is thus directed by the blocking plate  82  to flow out from a peripheral surface of a protruding portion of the separation suppressing member  80   c  from the open portion  59 . Accordingly, the gas fuel flowing out of the separation suppressing member  80   c  can be reliably dispersed. According to the third modified example, therefore, the separation of the gas fuel flow can be further suppressed and thus the gas flow sound resulting from the separation of gas fuel flow can be further reduced. 
     Herein, if a protruding amount (a protruding height) of the separation suppressing member  80   c  from the open portion  59  is small, there is a possibility that a necessary flow amount of fuel gas may not be ensured. In the third modified example, therefore, the protruding amount (the protruding height) H of the separation suppressing member  80   c  is set to 1/8 to 1/2 of the diameter D of the separation suppressing member  80   c  (i.e., H=D/8 to D/2). This setting of the protruding amount H is given for the reason that, if the protruding amount H is smaller than D/8, the separation suppressing member  80   c  may not provide a necessary flow amount of fuel gas, while if the protruding amount H is larger than D/2, the separation suppressing member  80   c  may not achieve a dispersion effect of fuel gas by the blocking plate  82 . 
     In the first to third modified examples, the separation suppressing members may be made of any one of a porous body and a mesh body. 
     In the fourth modified example, a separation suppressing member  80   d  is made of a porous body and, as shown in  FIG. 6 , is formed with a through hole  83  communicated with the discharge hole  62  and extending in a gas fuel flowing direction. The separation suppressing member  80   d  including the through hole  83  can prevent abrupt changes in passage cross-sectional area and suppress acceleration of gas fuel by making gas fuel pass through the through hole  83 . In the fourth modified example, accordingly, the separation of the gas fuel flow can be suppressed and thus the gas flow sound resulting from the separation of gas fuel flow can be reduced. The diameter d 2  of the through hole  83  is set to equal to or less than twice the diameter d 1  of the discharge hole  62  (d 2 ≦2×d 1 ). This setting is given for the reason that if the diameter d 2  of the through hole  83  exceeds twice the diameter dl of the discharge hole  62 , the through hole  83  could not suppress the acceleration of gas fuel. 
     According to the fuel injection apparatus  1  in the first embodiment explained in detail above, since the separation suppressing member  80  ( 80   a  to  80   d ) is placed in the open portion  59  (or in the discharge hole  62 ), the gas fuel discharged from the discharge hole  62  flows in the separation suppressing member  80  ( 80   a  to  80   d ) before accelerating and thus is decelerated and dispersed to flow out of the fuel injection apparatus  1 . Therefore, the separation of the gas fuel flow in the open portion  59  can be prevented and the gas flow sound resulting from the separation of gas fuel flow can be reduced. 
     Second Embodiment 
     A schematic entire configuration of a fuel supply unit of a second embodiment will be explained below referring to  FIGS. 7 to 9 .  FIG. 7  is a sectional view of the fuel supply unit of the second embodiment, and  FIGS. 8 and 9  are enlarged sectional views of a leading end and its surrounding in a fuel injection apparatus provided in the fuel supply unit. The fuel supply unit  124  is provided, as shown in  FIG. 7 , an inflow block  144 , an outflow block  146 , fuel injection apparatuses (injectors)  148 , a secondary pressure sensor  150 , a tertiary pressure sensor  152 , and others. 
     The inflow block  144  is a component for distributing fuel gas to the fuel injection apparatuses  148 . This inflow block  144  includes an inflow passage  158 , a cavity  160 , inflow ports  162 , a sensor hole  164 , and others. 
     The inflow passage  158  is a passage in which the fuel gas will flow. In the cavity  160 , the fuel injection apparatuses  148  are arranged at a predetermined spacing from each other. The inflow ports  162  are formed to connect the inflow passage  158  and the cavity  160 . In each of the inflow ports  162 , an inlet pipe  148   b  provided at an inlet of the corresponding fuel injection apparatus  148  is fitted. In the example shown in  FIG. 7 , the inlet pipes  148   b  of three fuel injection apparatuses  148  are arranged in parallel side by side to open in the inflow passage  158 . In the sensor hole  164 , the secondary pressure sensor  150  is fitted. The inflow block  144  is secured to the outflow block  146  with bolts  154 . 
     The outflow block  146  is a component for making streams of the fuel gas injected from the fuel injection apparatuses  148  merge or join into one stream. This outflow block  146  is formed with an outflow passage  168 , flow restricting members  169 , a sensor hole  172 , and others. The outflow block  146  has a two-block configuration. 
     The outflow passage  168  is a passage in which the fuel gas injected from the fuel injection apparatuses  148  will be discharged. The flow restricting members  169  are arranged within the outflow passage  168  in positions corresponding to the fuel injection apparatuses  148 . These flow restricting members  169  are configured to forcibly cause the gas fuel flowing out from the discharge holes  62  of the fuel injection apparatuses  148  into the outflow passage  168  to flow in a radial direction of each discharge hole  62 , that is, to be dispersed. The tertiary pressure sensor  152  is fitted in the sensor hole  172 . 
     In the present embodiment, herein, the flow restricting members  169  and the outflow block  146  are made as separate components. As an alternative, the flow restricting members  169  may be integrally formed with the outflow block  146 . In this case, the flow restricting member can be provided easily and inexpensively. This configuration can further achieve a reduced number of components as compared with the configuration provided with separate flow restricting members and further eliminate the need for a work to join the flow restricting members, thus leading to improved production efficiency. Accordingly, a fuel supply unit can be provided at lower cost than the foregoing configuration. 
     The fuel injection apparatuses  148  are held between the inflow block  144  and the outflow block  146 . Each of the fuel injection apparatuses  148  is placed with each leading end (a leading end located on a side close to a discharge hole  62 ) slightly protrudes into the outflow passage  168  to face the corresponding flow restricting member  169  as shown in  FIGS. 7 and 8 . It is to be noted that the fuel injection apparatuses  148  may be placed so that their leading ends are flush with the inner surface of the outflow passage  168  as shown in  FIG. 9 . 
     The fuel injection apparatuses  148  are connected with the inflow passage  158  and the outflow passage  168  to adjust a flow rate of fuel gas. The fuel injection apparatuses  148  are identical in basic structure to the fuel injection apparatus  1  of the first embodiment but are different in that the valve seat member has no open portion and is formed with only the nozzle hole (the discharge port  62 ) and that no separation suppressing member is provided. The present embodiment may also employ the fuel injection apparatus  1  of the first embodiment as each of the fuel injection apparatuses  148 . 
     In the example shown in  FIG. 7 , the fuel supply unit  124  includes three fuel injection apparatuses  148 . The number of fuel injection apparatuses  148  is not particularly limited and may be two or four or more. 
     Herein, the positional relationship between the fuel injection apparatuses  148  and the flow restricting members  169  will be briefly explained. As shown in  FIG. 8 , the flow restricting member  169  is placed such that the interval (distance) S between the leading end of the fuel injection apparatus  148  and the flow restricting member  169  is 1/4 to 1/2 of the diameter d 1  of the discharge hole  62  in the fuel injection apparatus  148  (S=d 1 /4 to d 1 /2). This setting of the interval S in such a range is based on the reason that if the interval S is smaller than d 1 /4, a necessary amount of fuel gas may not be provided, while if the interval S is larger than d 1 /2, a dispersion effect of fuel gas may not be achieved. 
     In the thus configured fuel supply unit  124 , fuel gas introduced in the inflow passage  158  is supplied into the outflow passage  168  through the fuel injection apparatuses  148 . At that time, since the passage cross-sectional area abruptly changes from each fuel injection apparatus  148  to the outflow passage  168 , the gas fuel flow or stream may be separated, leading to generation of gas flow sound (noise). 
     However, in the fuel supply unit  124 , the gas fuel discharged from the discharge holes  62  of the fuel injection apparatuses  148  impinges on the flow restricting members  169  before accelerating and thereby the gas fuel is directed to flow in the radial direction of the discharge holes  62 . Thus, the gas fuel discharged from the discharge holes  62  of the fuel injection apparatuses  148  is dispersed within the outflow passage  168 . Accordingly, the gas fuel injected from the fuel injection apparatuses  148  is decelerated and dispersed by the flow restricting members  169 . Consequently, separation of the gas fuel flow in the outflow passage  168  can be reliably suppressed. This can surely reduce the gas flow sound resulting from the separation of gas fuel flow. 
     According to the fuel supply unit  124  in the second embodiment explained in detail above, since the flow restricting members  169  are provided in the outflow passage  168  so as to face the discharge holes  162  of the fuel injection apparatuses  148 , the gas fuel injected from the discharge holes  162  are decelerated and dispersed by the flow restricting members  169  before acceleration. Accordingly the separation of the gas fuel flow in the outflow passage  169  can be reliably suppressed and thus the gas flow sound resulting from the separation of gas fuel flow can be surely reduced. 
     The foregoing embodiments are mere examples and do not give any limitations to the present invention. The present invention may be embodied in other specific forms without departing from the essential characteristics thereof. For instance, the foregoing embodiments show the example where hydrogen gas is supplied as the fuel gas. The present invention is also applicable to an apparatus configured to supply gas fuel (e.g., natural gas) other than hydrogen. 
     REFERENCE SIGNS LIST 
     
         
           1  Fuel injection apparatus 
           12  Valve element 
           14  Valve seat 
           34  Fuel passage 
           59  Open portion 
           60  Seat surface 
           62  Discharge port 
           80 ,  80   a - 80   d  Separation suppressing member 
           81  Downstream-side end face 
           82  Blocking plate 
           83  Through hole 
           124  Fuel supply unit 
           144  Inflow block 
           146  Outflow block 
           148  Fuel injection apparatus 
           158  Inflow passage 
           168  Outflow passage 
           169  Flow restricting member