WO2016152383A1

WO2016152383A1 - Supply passage structure of gaseous fuel

Info

Publication number: WO2016152383A1
Application number: PCT/JP2016/055848
Authority: WO
Inventors: 広藤木; 洋平小野
Original assignee: 愛三工業株式会社; トヨタ自動車株式会社
Priority date: 2015-03-20
Filing date: 2016-02-26
Publication date: 2016-09-29
Also published as: JP6411260B2; JP2016176438A; CN107250520A

Abstract

A supply passage structure of a gaseous fuel according to the present invention comprises a supply passage for supplying CNG, an injection valve for CNG that changes the supply manner of the CNG and that is provided in the supply passage, and a damping member disposed inside a cover body. At least one of an upstream end surface and a downstream end surface of the damping member has a slanted surface. The damping member is provided with a damping passage opening onto the slanted surface.

Description

Gas fuel supply passage structure

The present invention relates to a gaseous fuel supply passage structure including a supply passage for supplying gaseous fuel and a valve provided in the supply passage to change the supply mode of the gaseous fuel.

Patent Document 1 describes an example of an internal combustion engine that can selectively use liquid fuel and gaseous fuel. In such an internal combustion engine, generally, a fuel tank for storing high-pressure gaseous fuel is connected to an upstream end of a supply passage for supplying gaseous fuel. The supply passage is provided with an injection valve that injects gaseous fuel, a fuel hose that guides the gaseous fuel injected from the injection valve into the intake manifold, and the like.

By the way, when the injection valve is opened and gaseous fuel flows in, the pressure in the downstream supply passage on the downstream side of the injection valve rapidly increases. Therefore, when the injection valve is intermittently opened and closed, the pressure pulsation of the gaseous fuel is generated in the downstream supply passage. As a result, the intake manifold connected to the downstream supply passage may vibrate and generate noise.

The following methods are known as methods for suppressing the generation of noise accompanying opening and closing of the injection valve. For example, Patent Document 2 describes that a damping member is provided in the downstream supply passage in order to attenuate the pressure pulsation of the gaseous fuel in the downstream supply passage. The damping member has an upstream end surface located on the upstream side in the airflow direction in which the gaseous fuel flows in the downstream supply passage, and a downstream end surface located on the downstream side. The attenuation member has an attenuation path that opens on both the upstream end surface and the downstream end surface. The damping member has a narrowed portion having a narrower passage cross-sectional area than other portions at a midway position in the airflow direction in the damping path. When the gaseous fuel passes through the throttle portion, pressure loss is generated, so that the flow rate of the gaseous fuel is reduced. As a result, the pressure pulsation of the gaseous fuel in the downstream supply passage accompanying opening and closing of the injection valve is attenuated.

In order to increase the damping efficiency of pressure pulsation in the downstream supply passage, it is desirable to narrow the opening of the throttle part of the damping member. Thereby, gaseous fuel becomes difficult to flow in in a throttle part, and the pressure loss by having provided the attenuation member in the downstream supply passage can be enlarged. As a result, the pressure pulsation of the gaseous fuel in the downstream supply passage can be more effectively suppressed.

However, foreign matter may flow along with the gaseous fuel in the supply passage. Therefore, if the opening of the throttle portion is made too narrow, the opening of the throttle portion is blocked by foreign matter, and there is a possibility that gaseous fuel cannot be supplied into the intake manifold.

Such a problem occurs not only in the supply passage structure for supplying gaseous fuel to the internal combustion engine but also in the supply passage structure for supplying gaseous fuel such as hydrogen to the fuel cell, for example.

JP2012-233418A JP 2010-236391 A

An object of the present invention is to provide a gaseous fuel supply passage structure capable of increasing the attenuation efficiency of pressure pulsation of gaseous fuel in a supply passage downstream from a valve while suppressing reduction of the gaseous fuel supply efficiency. It is in.

In order to solve the above problems, according to a first aspect of the present invention, a supply passage for supplying gaseous fuel, a valve provided in the supply passage for changing the supply form of gaseous fuel, and a valve for the supply passage are provided. And a damping member disposed in a downstream supply passage that is a downstream portion, and when the flow direction of the gaseous fuel in the downstream supply passage is an airflow direction, the damping member is an upstream located upstream of the airflow direction. There is provided a gas fuel supply passage structure having an end face, a downstream end face located on the downstream side in the air flow direction, and a damping path that opens to both the upstream end face and the downstream end face. At least one of the upstream end surface and the downstream end surface has an inclined surface whose position in the airflow direction gradually changes as it approaches the apex, and the attenuation path is open to the inclined surface.

In order to solve the above problems, according to a second aspect of the present invention, a supply passage for supplying gaseous fuel, a valve provided in the supply passage for changing the supply mode of gaseous fuel, and a valve for the supply passage are provided. And a damping member disposed in a downstream supply passage that is a downstream portion, and when the flow direction of the gaseous fuel in the downstream supply passage is an airflow direction, the damping member is an upstream located upstream of the airflow direction. There is provided a gas fuel supply passage structure having an end face, a downstream end face located on the downstream side in the air flow direction, and a damping path that opens to both the upstream end face and the downstream end face. The upstream end surface is connected to a first inclined surface that inclines to the upstream side in the airflow direction as it approaches the radially inner side, and a radially inner end of the first inclined surface, and in the airflow direction as it approaches the radially inner side. A second inclined surface inclined to the downstream side, and an attenuation path is opened at a connection portion between the first inclined surface and the second inclined surface on the upstream end surface.

The block diagram which shows the outline of an internal combustion engine provided with the supply passage structure of the gaseous fuel of 1st Embodiment. The top view which shows the cover to which the injection valve for CNG is connected. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. The partial cross section figure which shows the constitution of the damping member. (A) is an operation | movement diagram explaining the effect | action at the time of CNG flowing in into an attenuation | damping path | route, (b) is an operation | movement figure explaining the effect | action at the time of CNG flowing out from an attenuation | damping path | route. Sectional drawing which shows schematic structure of the attenuation | damping member of 2nd Embodiment, and its peripheral member. Sectional drawing which shows schematic structure of the attenuation member of another example, and its peripheral member. Sectional drawing which shows schematic structure of a part of damping member of another example, and its peripheral member. Sectional drawing which shows schematic structure of the attenuation member of another example, and its peripheral member. Sectional drawing which shows schematic structure of a part of damping member of another example, and its peripheral member.

(First embodiment)
Hereinafter, an embodiment of a gas fuel supply passage structure according to the present invention will be described with reference to FIGS. 1 to 5B.

The internal combustion engine 10 is a bi-fuel internal combustion engine that can selectively use CNG (compressed natural gas) that is an example of gaseous fuel and gasoline that is an example of liquid fuel.
As shown in FIG. 1, an intake port 12 is formed inside a cylinder head 11 of the internal combustion engine 10. The cylinder head 11 is provided with a gasoline injection valve 21 that injects gasoline into the intake port 12. Further, the internal combustion engine 10 is provided with an intake manifold 14 that constitutes a part of the intake passage 13. The intake manifold 14 is provided with a cylindrical fuel injection cylinder 31. The fuel injection cylinder 31 communicates with a CNG injection valve 32 that injects CNG. When supplying CNG to the internal combustion engine 10, CNG flows into the intake manifold 14 from the fuel injection cylinder 31.

In the intake passage 13, an air-fuel mixture containing fuel and intake air is generated. The fuel is supplied to the intake passage 13 by opening / closing the gasoline injection valve 21 or opening / closing the CNG injection valve 32. The air-fuel mixture is sucked into the combustion chamber 15 of the internal combustion engine 10 and burned, and then becomes a combustion gas. The combustion gas is discharged from the combustion chamber 15 to the exhaust passage 16.

The internal combustion engine 10 includes a gasoline supply system 20 that supplies gasoline as fuel, and a CNG supply system 30 that supplies CNG as fuel. The gasoline supply system 20 includes a fuel pump 23 that sucks and pumps gasoline from the gasoline tank 22, and a gasoline delivery pipe 24 into which fuel pumped by the fuel pump 23 flows. Four gasoline injection valves 21 are connected to the gasoline delivery pipe 24 in the same manner as the number of cylinders of the internal combustion engine 10. The gasoline injection valve 21 is attached to each cylinder of the internal combustion engine 10, that is, to four intake ports 12 corresponding to each cylinder. By opening and closing the gasoline injection valve 21, the gasoline in the gasoline delivery pipe 24 is injected into each intake port 12 of the internal combustion engine 10.

The CNG supply system 30 is connected to a high-pressure fuel pipe 34 connected to a CNG tank 33 in which high-pressure CNG is stored, and a downstream end (right end in FIG. 1) of the high-pressure fuel pipe 34 in the fuel flow direction. The CNG delivery pipe 35 is provided. A CNG injection valve 32 is connected to the CNG delivery pipe 35. Further, a cover 36 extending substantially parallel to the CNG delivery pipe 35 is fixed to the CNG delivery pipe 35 with bolts. The CNG injection valves 32 are arranged at regular intervals while being sandwiched between the cover 36 and the CNG delivery pipe 35.

A fuel hose 37 is connected to the cover 36. The CNG injection valve 32 is provided with an injection unit that injects CNG. The injection portion of the CNG injection valve 32 is communicated with the fuel hose 37 through a through hole formed in the cover 36. A fuel injection cylinder 31 is connected to the downstream end of the fuel hose 37 in the fuel flow direction. When the CNG injection valve 32 is opened and closed, the CNG in the CNG delivery pipe 35 passes through the inside of the cover 36 and the fuel hose 37 and flows into the intake manifold 14 from the fuel injection cylinder 31. In the present embodiment, the high-pressure fuel pipe 34, the CNG delivery pipe 35, the cover 36, the fuel hose 37, and the fuel injection cylinder 31 constitute a supply passage for supplying CNG. Further, the cover 36, the fuel hose 37, and the fuel injection cylinder 31 constitute a downstream supply passage that is a portion on the downstream side of the CNG injection valve 32 of the supply passage.

The CNG supply system 30 is provided with only four downstream supply passages, the same as the number of cylinders of the internal combustion engine 10. CNG is supplied to each of the four cylinders of the internal combustion engine 10 through the downstream supply passage.

In the CNG supply system 30, a manual on-off valve 38 is provided between the CNG tank 33 and the high-pressure fuel pipe 34. A shutoff valve 39 that is opened and closed by a control device is provided downstream of the manual on-off valve 38 in the high-pressure fuel pipe 34. When both the manual on-off valve 38 and the shutoff valve 39 are open, the inflow of CNG from the CNG tank 33 into the high-pressure fuel pipe 34 is permitted. When at least one of the manual open / close valve 38 and the shutoff valve 39 is closed, the inflow of CNG from the CNG tank 33 into the high pressure fuel pipe 34 is prohibited.

A regulator 40 for reducing the pressure of CNG supplied from the CNG tank 33 is provided on the downstream side of the shutoff valve 39 in the high pressure fuel pipe 34. The regulator 40 reduces the CNG supplied into the CNG delivery pipe 35 to a predetermined pressure.

Next, with reference to FIG.2 and FIG.3, the connection structure of the CNG injection valve 32 and the cover 36 is demonstrated.
As shown in FIGS. 2 and 3, the cover 36 includes a cover main body 42 and the same number of connection pipes 43 as the CNG injection valves 32. The cover body 42 is provided with the same number of through holes 50 as the CNG injection valve 32. The direction in which CNG flows through the through hole 50 is referred to as an airflow direction X. 2 and 3, the upper side is the upstream side in the airflow direction X, and the lower side is the downstream side in the airflow direction X.

The injection part 32A of the CNG injection valve 32 is inserted into the through-hole 50 from the upstream opening 51 in the airflow direction X. For this reason, the injection part 32 A of the CNG injection valve 32 is located upstream in the airflow direction X in the through hole 50. A seal member 44 is provided between the peripheral wall of the cover main body 42 forming the through hole 50 and the CNG injection valve 32 to ensure airtightness between the cover main body 42 and the CNG injection valve 32. Yes.

Further, the connection pipe 43 is press-fitted into the through hole 50 from the opening on the downstream side in the airflow direction X. A fuel hose 37 is connected to the cover 36 through a connection pipe 43. Further, in the through hole 50, a damping member 60 that attenuates the pressure pulsation of CNG in the downstream supply passage is provided between the CNG injection valves 32 arranged in the airflow direction X and the upstream end 43 A of the connection pipe 43. Is provided. When the position where the damping member 60 is disposed in the through hole 50 is the first passage portion, the opening 43B formed at the upstream end 43A of the connection pipe 43 is connected to the downstream end of the first passage portion. It functions as a second passage part. The passage diameter of the opening 43B is smaller than the passage diameter of the through hole 50 which is the first passage portion. Therefore, an annular step is formed at the boundary portion between the first passage portion and the second passage portion.

Next, the damping member 60 will be described with reference to FIGS. 3 and 4.
As shown in FIGS. 3 and 4, the damping member 60 includes a member body 61 having a cylindrical shape. The member main body 61 is opposed to the injection portion 32A of the CNG injection valve 32 and is located upstream of the airflow direction X (upper side in the drawing), and is opposed to the upstream end 43A of the connection pipe 43 and in the airflow direction. And a downstream end face 63 located on the downstream side (lower side in the figure) of X.

The upstream end surface 62 is provided with an upstream inclined surface 62A that is inclined toward the downstream side (lower side in the drawing) in the airflow direction X as it approaches the radially inner side. The vertex A1 is set at the center of the through hole 50 in the radial direction. The upstream inclined surface 62A is inclined to the downstream side in the airflow direction X as it approaches the vertex A1 from the radially outer end. The radially inner end of the upstream inclined surface 62 A is located between the peripheral wall 421 of the cover body 42 that forms the through hole 50 and the axial center of the through hole 50.

The downstream end surface 63 is provided with a downstream inclined surface 63A that is inclined toward the downstream side (lower side in the figure) in the airflow direction X as it approaches the radially inner side. The apex A2 is set at the center of the through hole 50 in the radial direction. The upstream inclined surface 62A is inclined to the downstream side in the airflow direction X as it approaches the vertex A2 from the radially outer end. The radially inner end of the downstream inclined surface 63 A is located between the peripheral wall 421 of the cover main body 42 that forms the through hole 50 and the axial center of the through hole 50. The radially inner end of the downstream inclined surface 63A is disposed at the same radial position as the radially inner end of the upstream inclined surface 62A.

Also, the attenuation member 60 is provided with a plurality of attenuation paths 65 arranged at different positions in the circumferential direction. The plurality of attenuation paths 65 are arranged at equal intervals in the circumferential direction of the attenuation member 60. Each of the plurality of attenuation paths 65 extends in the axial direction of the through hole 50 (vertical direction in the drawing). Each attenuation path 65 opens to the upstream inclined surface 62 A of the upstream end surface 62 and opens to the downstream inclined surface 63 A of the downstream end surface 63. The opening 651 on the upstream side of the attenuation path 65 is located between the radially outer end portion and the radially inner end portion of the upstream inclined surface 62A, specifically, substantially at the center in the radial direction of the upstream inclined surface 62A. Yes. Similarly, the opening 652 on the downstream side of the attenuation path 65 is between the radially outer end and the radially inner end of the downstream inclined surface 63A, specifically, substantially at the center in the radial direction of the downstream inclined surface 63A. positioned.

Next, with reference to FIG. 5A and FIG. 5B, the operation of attenuating the pressure pulsation of CNG in the downstream supply passage by the injection of CNG from the CNG injection valve 32 will be described.
As shown in FIG. 5A, CNG injected from the CNG injection valve 32 flows along the upstream inclined surface 62 A of the damping member 60 and then flows into the damping path 65 through the opening 651. At this time, the CNG that has interfered with the upstream inclined surface 62A on the radially outer side than the opening 651 is guided to the opening 651 by the upstream inclined surface 62A.

On the other hand, the CNG that has interfered with the upstream inclined surface 62A radially inward of the opening 651 flows in the direction opposite to the airflow direction X on the upstream inclined surface 62A, and then flows into the attenuation path 65 through the opening 651. By generating a flow of CNG in the direction opposite to the airflow direction X in this way, the pressure loss when CNG flows into the attenuation path 65 can be increased.

As shown in FIG. 5B, the CNG that has flowed through the attenuation path 65 flows out of the attenuation member 60 through the opening 652 of the downstream inclined surface 63A. Here, the outer edge of the opening 652 in the radial direction is located on the upstream side (upper side in the drawing) of the airflow direction X with respect to the edge of the opening 652 on the inner side in the radial direction. Therefore, most of the CNG that has flowed out of the opening 652 flows outward in the radial direction. After the CNG flows from the opening 652 toward the outside in the radial direction, it interferes with the peripheral wall 421 of the cover main body 42, thereby changing the direction in which the CNG flows. Thus, the CNG that has flowed out of the opening 652 actively interferes with the peripheral wall 421 to change the direction in which the CNG flows, whereby the pressure loss when the CNG flows out of the attenuation path 65 can be increased.

CNG that has interfered with the peripheral wall 421 flows downstream in the airflow direction X along the peripheral wall 421. However, a step is formed at the connection portion between the cover main body 42 and the connection pipe 43. For this reason, the diameter of the passage forming the downstream supply passage is narrowed in the middle. Therefore, CNG that flows downstream in the airflow direction X along the peripheral wall 421 passes through the opening 43B of the connection pipe 43 after interfering with the step. That is, even when the direction in which the CNG flows is changed again due to the step, a pressure loss occurs in the CNG flow.

Therefore, even if CNG is injected from the CNG injection valve 32, the flow rate of CNG is effectively decelerated by the damping member 60. As a result, the pressure pulsation of CNG in the downstream supply passage that occurs when CNG is intermittently injected from the CNG injection valve 32 is effectively attenuated. Therefore, vibration of the intake manifold due to intermittent injection of CNG from the CNG injection valve 32 is suppressed.

Further, the pressure loss of the CNG flow can be increased without reducing the cross-sectional area of the attenuation path 65. Therefore, the passage cross-sectional area of the attenuation path 65 can be made relatively wide so that the

openings

651 and 652 are not blocked by the foreign matter flowing together with the CNG.

As mentioned above, according to the said structure and effect | action, the effect shown below can be acquired.
(1) The downstream inclined surface 63A is provided on the downstream end surface 63 of the attenuation member 60, and the attenuation path 65 opens to the downstream inclined surface 63A. Therefore, the CNG is guided toward the peripheral wall 421 of the cover body 42 after flowing out from the opening 652 of the attenuation path 65 formed in the downstream inclined surface 63A. Then, the direction in which the CNG flowing out from the attenuation path 65 flows is changed by the peripheral wall 421. Thereby, a pressure loss occurs in the flow of CNG, and the flow rate of CNG becomes slow. Therefore, the damping efficiency of the CNG pressure pulsation in the downstream supply passage can be increased by opening the damping path 65 in the downstream inclined surface 63A.

(2) Further, the CNG that has flowed out of the attenuation path 65 flows along the peripheral wall 421 of the cover body 42 and then interferes with the step formed at the connection portion between the cover body 42 and the connection pipe 43. Thereby, further pressure loss occurs in the flow of CNG, and the flow rate of CNG is further slowed down. Therefore, it is possible to further increase the attenuation efficiency of the pressure pulsation of CNG in the downstream supply passage.

(3) An upstream inclined surface 62A is provided on the upstream end surface 62 of the attenuation member 60, and the attenuation path 65 opens to the upstream inclined surface 62A. Therefore, CNG injected from the CNG injection valve 32 flows in the direction opposite to the airflow direction X along the upstream inclined surface 62A, and then flows into the attenuation path 65 that opens to the upstream inclined surface 62A. That is, before the CNG flows into the opening 651 of the attenuation path 65, a CNG flow in the direction opposite to the airflow direction X is generated. This increases the pressure loss of the CNG flow. Therefore, the damping efficiency of the CNG pressure pulsation in the downstream supply passage can be increased by opening the damping path 65 in the upstream inclined surface 62A.

(4) Compared with the case where an upstream inclined surface that inclines toward the upstream side in the airflow direction X from the radially outer end toward the apex A1 is provided on the upstream end surface 62 of the attenuation member 60, the attenuation member 60 is used for CNG. It can be brought close to the injection valve 32. Therefore, the degree of freedom of the position of the damping member 60 in the downstream supply passage can be increased.

(5) The attenuation member 60 is configured to increase the pressure loss of the CNG flow at least before CNG flows into the attenuation path 65 and after CNG flows out from the attenuation path 65. Thereby, the attenuation efficiency of the pressure pulsation of CNG in the downstream supply passage can be increased without narrowing the

openings

651 and 652 of the attenuation passage 65 or reducing the passage diameter of the attenuation passage 65 itself. . Therefore, even if foreign matter flows together with CNG, the opening of the attenuation path 65 is less likely to be blocked by foreign matter. Therefore, it is possible to increase the attenuation efficiency of the pressure pulsation of CNG in the downstream supply passage while suppressing the reduction of the supply efficiency of CNG.

(Second Embodiment)
Next, a second embodiment of the gaseous fuel supply passage structure of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in the shape of the upstream end face 62 of the damping member 60. Therefore, in the following description, parts different from the first embodiment will be mainly described, the same reference numerals are given to the same or corresponding member configurations as those of the first embodiment, and the description thereof will be omitted.

As shown in FIG. 6, the upstream end surface 62 of the damping member 60 has a first inclined surface 62B and a second inclined surface 62C. The first inclined surface 62B is located on the radially outer side than the second inclined surface 62C. The radially inner end of the first inclined surface 62B is connected to the radially outer end of the second inclined surface 62C. The first inclined surface 62B is inclined to the upstream side (upper side in the drawing) of the airflow direction X as it approaches the radially inner side. The second inclined surface 62C is inclined to the downstream side (lower side in the figure) in the airflow direction X as it approaches the radially inner side. Each attenuation path 65 opens at a connection portion between the first inclined surface 62B and the second inclined surface 62C.

Next, with reference to FIG. 6, an operation when CNG injected from the CNG injection valve 32 flows into the attenuation path 65 will be described.
As shown in FIG. 6, part of CNG injected from the CNG injection valve 32 interferes with the first inclined surface 62 B and then flows into the attenuation path 65 through the opening 651. Further, at least a part of the remaining CNG interferes with the second inclined surface 62C and then flows into the attenuation path 65 through the opening 651.

The CNG that has interfered with the first inclined surface 62B flows in the direction opposite to the airflow direction X on the first inclined surface 62B, and then flows into the attenuation path 65 through the opening 651. By generating a flow of CNG in the direction opposite to the airflow direction X in this way, the pressure loss when CNG flows into the attenuation path 65 can be increased.

Similarly, the CNG that has interfered with the second inclined surface 62C flows in the direction opposite to the airflow direction X on the second inclined surface 62C, and then flows into the attenuation path 65 through the opening 651. By generating a flow of CNG in the direction opposite to the airflow direction X in this way, the pressure loss when CNG flows into the attenuation path 65 can be increased.

As described above, according to the second embodiment, in addition to the effects (1), (2), and (6) of the first embodiment, the following effects can be obtained.
(7) The first inclined surface 62B and the second inclined surface 62C are provided on the upstream end surface 62 of the attenuation member 60, and the attenuation path 65 is provided at the connection portion between the first inclined surface 62B and the second inclined surface 62C. It is open. Therefore, before the CNG flows into the opening 651 of the attenuation path 65, a CNG flow in the direction opposite to the airflow direction X can be generated. As a result, the pressure loss of the CNG flow increases before CNG flows into the opening 651. Therefore, it is possible to increase the damping efficiency of the CNG pressure pulsation in the downstream supply passage.

Each of the above embodiments may be modified as follows.
In each embodiment, the number of attenuation paths 65 provided in the attenuation member 60 may be one or plural.

In each embodiment, the radial positions of the plurality of attenuation paths 65 may not all be the same.
-In 1st Embodiment, if the upstream inclined surface 62A is provided in the upstream end surface 62 of the attenuation member 60, and the attenuation | damping path | route 65 is opening to the upstream inclined surface 62A, as shown in FIG. The downstream end surface 63 may not be provided with the downstream inclined surface 63A. Also in this case, the same effects as the above (3) to (5) can be obtained.

In the first embodiment, the vertex A1 may be provided at a position other than the radial center of the through hole 50 as long as it is inside the radially outer end of the upstream inclined surface 62A. In this case as well, the same effect as the above (3) to (5) can be obtained by inclining the upstream inclined surface 62A toward the downstream side in the airflow direction X as it approaches the apex A1 from the radially outer end. it can. Further, the vertex A1 may be set at a radial position other than the vertex A2.

-In 2nd Embodiment, the 1st inclined surface 62B and the 2nd inclined surface 62C are provided in the upstream end surface 62 of the damping member 60, and the attenuation | damping path | route 65 is the 1st inclined surface 62B and the 2nd inclined surface 62C. The downstream inclined surface 63 A may not be provided on the downstream end surface 63 of the damping member 60 as long as the connection portion is open. Also in this case, the same effects as the above (6) and (5) can be obtained.

The shape of the upstream inclined surface provided on the upstream end surface 62 of the damping member 60 may be any shape as long as the position in the airflow direction X gradually changes from the radially outer end toward the vertex A1. .

For example, as shown in FIG. 8, the upstream end surface 62 may be provided with an upstream inclined surface 62A1 that inclines toward the upstream side in the airflow direction X as it approaches the radially inner side. In the example shown in FIG. 8, the vertex A1 is set at the center in the radial direction of the through hole 50, and the upstream inclined surface 62A1 is inclined toward the upstream side in the airflow direction X as it approaches the vertex A1. Further, if it is inside the radially outer end of the upstream inclined surface 62A1, the apex A1 is provided at a position other than the radial center of the through hole 50, and the upstream inclined surface 62A1 is disposed from the radially outer end. You may make it incline to the upstream of the airflow direction X as approaching vertex A1.

In such a case, the CNG injected from the CNG injection valve 32 flows along the upstream inclined surface 62A1 of the upstream end surface 62 and then flows into the attenuation path 65 through the opening 651. At this time, the CNG that has interfered with the upstream inclined surface 62A1 radially inward of the opening 651 is guided to the opening 651 by the upstream inclined surface 62A1. On the other hand, the CNG that has interfered with the upstream inclined surface 62A1 radially outside the opening 651 flows in the direction opposite to the airflow direction X on the upstream inclined surface 62A1, and then flows into the attenuation path 65 through the opening 651. To do. By generating a flow of CNG in the direction opposite to the airflow direction X in this way, the pressure loss when CNG flows into the attenuation path 65 can be increased. Therefore, an effect equivalent to the above (3) can be obtained.

When such an upstream inclined surface 62A1 is provided on the upstream end surface 62, a downstream inclined surface may or may not be provided on the downstream end surface 63 of the damping member 60.
-In 1st Embodiment, if the downstream inclined surface 63A is provided in the downstream end surface 63 of the damping member 60, and the attenuation | damping path | route 65 is opening to the downstream inclined surface 63A, as shown in FIG. The upstream inclined surface 62 A may not be provided on the upstream end surface 62. In this case, the same effects as in the above (1) and (5) can be obtained.

In each embodiment, the apex A2 may be provided at a position other than the radial center of the through hole 50 as long as it is inside the radially outer end of the downstream inclined surface 63A. Also in this case, the effect similar to the above (1) and (5) can be obtained by inclining the downstream inclined surface 63A toward the downstream side in the airflow direction X as it approaches the apex A2 from the radially outer end. it can.

As shown in FIG. 10, the downstream end surface 63 is provided with a downstream inclined surface 63A1 that is inclined toward the upstream side (upward in the drawing) in the airflow direction X as it approaches the radially inner side, and each attenuation path 65 is provided on the downstream inclined surface 63A1. May be opened. In the example shown in FIG. 10, the vertex A2 is set at the center in the radial direction of the through hole 50, and the downstream inclined surface 63A1 is inclined to the upstream side in the airflow direction X as it approaches the vertex A2 from the radially outer end. Yes. If it is inside the radially outer end of the downstream inclined surface 63A1, the vertex A2 is provided at a position other than the radial center of the through hole 50, and the upstream inclined surface 62A1 is moved from the radially outer end to the vertex A2. You may make it incline to the upstream of the airflow direction X as it approaches.

In this case, the radially inner edge of the opening 652 of each attenuation path 65 is located on the upstream side (upper side in the figure) in the airflow direction X with respect to the radially outer edge. Therefore, most of CNG flowing out from each opening 652 flows toward the inside in the radial direction. In this way, the CNGs flow radially inward from the openings 652, interfere with each other, merge, and flow downstream in the airflow direction X. Thus, by causing the CNG flowing through each attenuation path 65 to interfere immediately after flowing out from each opening 652, a pressure loss occurs in the CNG flow, and the flow rate of the CNG becomes slow. Therefore, by providing the downstream end surface 63 with the downstream inclined surface 63A1 as shown in FIG. 10, it is possible to increase the attenuation efficiency of the CNG pressure pulsation in the downstream supply passage.

When the downstream inclined surface 63A1 is provided on the downstream end surface 63, by providing a plurality of openings 652 so that the circumferential positions differ by “180 °”, the pressure loss immediately after the CNG flows out from each attenuation path 65 is increased. can do. In this case, the upstream end surface 62 of the damping member 60 may be provided with the upstream inclined surfaces 62A and 62A1, or both the first inclined surface 62B and the second inclined surface 62C. It is not necessary to provide an inclined surface.

The position of the upstream inclined surfaces 62A and 62A1 in the airflow direction X may be set so that the gradient gradually changes as it approaches the apex A1 from the radially outer end.
-You may set the position of the downstream inclined surfaces 63A and 63A1 in the airflow direction X so that a gradient may change gradually instead of a fixed gradient as it approaches the vertex A2 from the radially outer end.

The damping member 60 may be disposed outside the cover main body 42 as long as it is in the downstream supply passage. For example, the damping member 60 may be disposed in the fuel hose 37.
The damping member 60 can also be employed for a supply passage that supplies gaseous fuel such as hydrogen to the fuel cell. Also in this case, the damping member 60 may be provided on the downstream side of the injection valve that injects the gaseous fuel.

The valve provided in the supply passage is not limited to the injection valve described in the above embodiments. Any valve may be adopted as long as it is provided in the supply passage and changes the supply mode of the gaseous fuel.

Claims

A supply passage for supplying gaseous fuel; a valve provided in the supply passage for changing the supply mode of gaseous fuel; and a damping member disposed in a downstream supply passage that is a portion of the supply passage downstream of the valve. When the direction in which the gaseous fuel flows in the downstream supply passage is an air flow direction, the damping member is positioned upstream of the air flow direction and on the downstream side of the air flow direction. In a gas fuel supply passage structure having a downstream end face and a damping path that opens to both the upstream end face and the downstream end face,
At least one of the upstream end surface and the downstream end surface has an inclined surface whose position in the airflow direction gradually changes as it approaches the apex, and the attenuation path opens to the inclined surface. Fuel supply passage structure.
The gas fuel supply passage structure according to claim 1,
The downstream end surface has the inclined surface;
The apex is set inside the radially outer end of the downstream end face;
The gas fuel supply passage structure, wherein the inclined surface is inclined to the downstream side in the airflow direction as it approaches the apex from the radially outer end.
In the gas fuel supply passage structure according to claim 2,
The downstream supply passage has a first passage portion where the damping member is located, and a second passage portion connected to a downstream end of the first passage portion,
A gas fuel supply passage structure in which a passage diameter of the second passage portion is smaller than a passage diameter of the first passage portion.
The gas fuel supply passage structure according to claim 1,
The attenuation member is provided with a plurality of attenuation paths arranged at different positions in the circumferential direction,
The downstream end surface has the inclined surface;
The apex is set inside the radially outer end of the downstream end face;
The gas fuel supply passage structure, wherein the inclined surface is inclined toward the upstream side in the airflow direction as it approaches the apex from the radially outer end.
The gaseous fuel supply passage structure according to any one of claims 1 to 4,
The upstream end surface has the inclined surface;
The apex is set inside the radially outer end of the upstream end face;
The gas fuel supply passage structure, wherein the inclined surface is inclined to the downstream side in the airflow direction as it approaches the apex from the radially outer end.
The gaseous fuel supply passage structure according to any one of claims 1 to 4,
The upstream end surface has the inclined surface;
The apex is set inside the radially outer end of the upstream end face;
The gas fuel supply passage structure, wherein the inclined surface is inclined to the upstream side in the airflow direction as approaching the apex from the radially outer end.
The gaseous fuel supply passage structure according to any one of claims 1 to 6,
The valve is a gas fuel supply passage structure which is an injection valve for injecting gaseous fuel.
A supply passage for supplying gaseous fuel; a valve provided in the supply passage for changing the supply mode of gaseous fuel; and a damping member disposed in a downstream supply passage that is a portion of the supply passage downstream of the valve. When the direction in which the gaseous fuel flows in the downstream supply passage is an air flow direction, the damping member is positioned upstream of the air flow direction and on the downstream side of the air flow direction. In a gas fuel supply passage structure having a downstream end face and a damping path that opens to both the upstream end face and the downstream end face,
The upstream end surface is connected to a first inclined surface that inclines toward the upstream side in the airflow direction as it approaches the radially inner side, and a radially inner end portion of the first inclined surface, and as it approaches the radially inner side. A second inclined surface inclined to the downstream side in the airflow direction,
In the upstream end face, the attenuation path is opened at a connection portion between the first inclined face and the second inclined face.