FUEL SUPPLY APPARATUS AND FUEL SUPPLY UNIT

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 26a. This through hole 26a 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 28a. The casing 28 is made of soft magnetic material (e.g., electromagnetic stainless steel). The casing 28 accommodates, in the through hole 28a, 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 28a 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 80a placed in the open portion 59 is designed such that a downstream-side end face 81 is spherical. The thus configured separation suppressing member 80a can disperse gas fuel flowing out of the separation suppressing member 80a. 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 80a 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 80b 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 80b 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 80b (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 80c 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 80c. The blocking plate 82 serves to block outflow of gas fuel from the downstream-side end face of the separation suppressing member 80c. The gas fuel having passed through the separation suppressing member 80c is thus directed by the blocking plate 82 to flow out from a peripheral surface of a protruding portion of the separation suppressing member 80c from the open portion 59. Accordingly, the gas fuel flowing out of the separation suppressing member 80c 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 80c 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 80c is set to 1/8 to 1/2 of the diameter D of the separation suppressing member 80c (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 80c 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 80c 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 80d 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 80d 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 d2 of the through hole 83 is set to equal to or less than twice the diameter d1 of the discharge hole 62 (d2≦2×d1). This setting is given for the reason that if the diameter d2 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 (80a to 80d) 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 (80a to 80d) 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 148b provided at an inlet of the corresponding fuel injection apparatus 148 is fitted. In the example shown in FIG. 7, the inlet pipes 148b 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 d1 of the discharge hole 62 in the fuel injection apparatus 148 (S=d1/4 to d1/2). This setting of the interval S in such a range is based on the reason that if the interval S is smaller than d1/4, a necessary amount of fuel gas may not be provided, while if the interval S is larger than d1/2, 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, 80a-80d 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

FUEL SUPPLY APPARATUS AND FUEL SUPPLY UNIT

Information

Publication Number

Date Filed

Date Published

Inventors

Original Assignees

CPC

International Classifications

Abstract

Description

Claims

Priority Claims (1)