Patent Application
20100269956
The present invention relates to a gas supply structure, and relates particularly to a gas supply structure having improved gas sealing properties.
Fuel cells are mounted in electric vehicles and hybrid vehicles. Further, solid polymer fuel cells maybe used as these fuel cells. The mechanism for electric power generation within these solid polymer fuel cells generally involves supplying a fuel gas such as a hydrogen-containing gas to a fuel electrode (the anode-side electrode) and supplying an oxidant gas such as a gas containing mainly oxygen (O2) or air to an air electrode (the cathode-side electrode), wherein the hydrogen-containing gas supplied to the fuel electrode is decomposed into electrons and hydrogen ions (H+) under the action of the electrode catalyst, and these electrons pass through an external circuit to migrate from the fuel electrode to the air electrode, thereby generating an electric current. Meanwhile, the hydrogen ions (H+) pass through an electrolyte membrane sandwiched between the fuel electrode and the air electrode to reach the air electrode, and undergo bonding with oxygen and the electrons that have passed though the external circuit, thus generating reaction water (H2O).
In order to enable the fuel cell described above to be supplied with a hydrogen-containing gas (such as hydrogen gas), the electric vehicle or hybrid vehicle is fitted with a hydrogen fuel storage system. This hydrogen fuel storage system comprises a high-pressure hydrogen container, and a hydrogen filling connector that functions as the fastening section when filling the high-pressure hydrogen container with high-pressure hydrogen from a dispenser at a hydrogen station.
As illustrated in
The driving range for a vehicle in which the high-pressure hydrogen container has been filled with 35 MPa high-pressure hydrogen gas using the type of hydrogen filling connector 300 illustrated in
For example, one example of a novel structure for a hydrogen filling connector capable of hydrogen filling at 70 MPa that has been proposed by a German company (hereafter referred to as “the German proposed shape”) is illustrated in
Further, one example of a novel structure for a hydrogen filling connector capable of hydrogen filling at 70 MPa that has been proposed by a Japanese company (hereafter referred to as “the Japanese proposed shape”) is illustrated in
However, as the nozzle length increases, there is an increased possibility that foreign matter adhered to the nozzle surface may become incorporated within the gas from the nozzle tip inside the receptacle gas passage. Neither the German proposed shape nor the Japanese proposed shape is provided with a device for inhibiting foreign matter contamination.
Patent Document 1 proposes a fuel filling system comprising a nozzle for gas filling, and a receptacle into which gas is supplied from the nozzle, wherein the system is provided with a malfunction diagnosis device that diagnoses any malfunction of the receptacle or nozzle during gas filling. However, the fuel filling system proposed in Patent Document 1 is not provided with a device for inhibiting foreign matter contamination.
Patent Document 2 proposes a structure for an optical communication sleeve in which an engagement member having a protruding sliding surface is provided on the inner peripheral surface of a ferrule insertion hole of the optical communication sleeve, so that upon insertion, dust on the surface of the ferrule is removed, thereby preventing dust from penetrating inside the optical communication sleeve. Further, Patent Documents 3 and 4 propose structures for filters used in removing toxic components or contaminants from a passing gas stream.
Patent Document 1: JP 2006-177253 A
Patent Document 2: JP 2005-241882 A
Patent Document 3: JP 2003-225540 A
Patent Document 4: JP 08-75098 A
As mentioned above, none of the novel structures for hydrogen filling connectors that have been proposed to accommodate the transition to increased pressure of the filling gas is provided with a device for inhibiting contamination of the receptacle gas passage by foreign matter that has adhered to the nozzle surface as a result of the increased nozzle length.
Accordingly, in the case of a hydrogen filling connector of the German proposed shape, if the nozzle is inserted into the receptacle insertion hole during gas filling with foreign matter adhered to the nozzle surface, then the foreign matter adheres to the O-rings inside the receptacle, which are provided so that no space exists between the nozzle and the O-rings, and adheres particularly to the O-ring provided in the vicinity of the nozzle tip. If this foreign matter causes damage to the O-ring surface, then there is a possibility that the sealing properties may deteriorate. Similarly, in the case of a hydrogen filling connector of the Japanese proposed shape, if foreign matter is adhered to the inner peripheral surface of the receptacle insertion hole, then that foreign matter tends to adhere to the O-ring in the vicinity of the nozzle tip, and if this causes damage to the O-ring surface, then there is a possibility that the sealing properties may deteriorate.
Furthermore, during filling of the liquid fuel, in order to prevent an increase in temperature of the high-pressure hydrogen container (such as a tank), filling is typically conducted with the liquid fuel at a low temperature of approximately −40° C. During this filling, if water has adhered to the nozzle of the hydrogen filling connector then it freezes and bonds to the nozzle as ice, which can make it difficult to remove the nozzle from the receptacle. Moreover, if the nozzle is forcibly pulled out of the receptacle in this state, then there is a possibility that the O-rings inside the hydrogen filling connector may partially detach, resulting in a loss in the sealing properties. These issues associated with low-temperature liquid fuel filling are difficult to resolve with conventional hydrogen filling connector structures and the conventional technologies described above.
The present invention has been developed in light of the issues described above, and provides a gas supply structure that is able to prevent foreign matter on the nozzle surface from adhering to the O-rings inside the gas supply structure when the nozzle is inserted in the receptacle during gas filling.
In order to achieve the object described above, the gas supply structure of the present invention has the features described below.
(1) A gas supply structure comprising a nozzle that supplies a gas, a receptacle that receives supply of the gas by insertion of the nozzle therein, an O-ring that is provided within the receptacle, seals the nozzle and the receptacle, and slides against the nozzle during insertion of the nozzle, and a foreign matter removal member that is provided within the receptacle in a position closer to an insertion hole for the nozzle than the O-ring, and further comprising an insertion hole-side O-ring that is provided in the receptacle in a vicinity of an insertion hole.
Because the foreign matter removal member provided in the receptacle is positioned closer to the insertion hole for the nozzle than the O-ring provided within the receptacle, the foreign matter removal member removes foreign matter that exists on the nozzle surfaces, starting from the tip of the nozzle, as the nozzle undergoes insertion within the receptacle. Accordingly, foreign matter on the tip of the nozzle and the nozzle surface is inhibited from adhering to the O-ring.
(2) A gas supply structure comprising a nozzle that supplies a gas, a receptacle that receives supply of the gas by insertion of the nozzle therein, an O-ring that is provided on the nozzle, seals the nozzle and the receptacle, and slides against the receptacle during insertion of the nozzle, and a foreign matter removal member that is provided on the nozzle in a position closer to the tip of the nozzle than the O-ring.
Because the foreign matter removal member provided on the nozzle is positioned closer to the tip of the nozzle than the O-ring provided on the nozzle, the foreign matter removal member is able to remove foreign matter that exists on the inner peripheral surface that extends inwards from the insertion hole of the receptacle as the nozzle undergoes insertion within the receptacle. Accordingly, adhesion of foreign matter to the O-ring provided on the nozzle is inhibited.
(3) A gas supply structure comprising a receptacle that receives supply of a gas by insertion of a nozzle therein, an O-ring that is provided within the receptacle, seals the nozzle and the receptacle, and slides against the nozzle during insertion of the nozzle, and a foreign matter removal member that is provided within the receptacle in a position closer to an insertion hole for the nozzle than the O-ring, and further comprising an insertion hole-side O-ring that is provided in the receptacle in a vicinity of an insertion hole.
Because the foreign matter removal member provided in the receptacle is positioned closer to the insertion hole for the nozzle than the O-ring provided within the receptacle, the foreign matter removal member removes foreign matter that exists on the nozzle surfaces, starting from the tip of the nozzle, as the nozzle undergoes insertion within the receptacle. Accordingly, foreign matter on the tip of the nozzle and the nozzle surface is inhibited from adhering to the O-ring.
(4) A gas supply structure comprising a receptacle that receives supply of a gas by insertion of a nozzle therein, an O-ring that is provided on the nozzle, seals the nozzle and the receptacle, and slides against the nozzle during insertion of the nozzle, and a foreign matter removal member that is provided on the nozzle in a position closer to the tip of the nozzle than the O-ring.
(5) The gas supply structure according to (2) or (4) above, further comprising an insertion hole-side O-ring provided in the receptacle in the vicinity of the insertion hole.
(6) The gas supply structure according to any one of (1) to (5) above, further comprising a tank for storing the gas, a filter having a small loss coefficient disposed in the upstream side of a gas passage connecting the receptacle to the tank, and a filter having a large loss coefficient disposed in the downstream side of the gas passage.
The two filters described above trap foreign matter within the gas supplied to the tank, and by combining a filter having a relatively small loss coefficient with a filter having a relatively large loss coefficient, the differential pressure before and after the two filters can be reduced compared with the case of a single filter. As a result, blockages of the entire filtering system within the gas passage can be inhibited.
(7) The gas supply structure according to any one of (1) to (6) above, wherein the foreign matter removal member has a sliding resistance, determined on the basis of a pull-out load measurement, that is not less than 300 N and not more than 500 N.
By using a foreign matter removal member having the sliding resistance defined above, the removal performance is improved for foreign matter that exists inside the gas supply structure, and particularly for water.
The present invention is able to inhibit foreign matter contamination of gas supply structures.
Embodiments of the present invention are described below with reference to the drawings. Further, the gas supply structure of the present invention is described below using the example of a hydrogen filling connector that is used for filling high-pressure gas at 70 MPa.
An example of a gas supply structure according to a first embodiment of the present invention is illustrated in
In this description, the term “foreign matter” used in both this embodiment and the other embodiments described below describes substances that can adhere to the tip and surface of the nozzle, and includes dust and moisture and the like.
In a more detailed description, the gas supply structure 100 according to the present embodiment comprises, in the case of the aforementioned German proposed shape, a nozzle 10 having a gas supply passage 12, and a receptacle 20 having an insertion hole 22 into which the nozzle 10 is inserted to achieve connection, wherein the receptacle 20 is provided with a first O-ring 24 that is provided in the vicinity of the insertion hole 22 for the purpose of gas sealing, and a second O-ring 28 that is provided further downstream the gas supply path than the first O-ring 24 for the purpose of gas sealing, a portion of the second O-ring 28 is bonded to a recessed section in the receptacle 20 using a bonding material 27, and a foreign matter removal member 26 is positioned closer to the insertion hole 22 than the second O-ring 28. Further, the foreign matter removal member 26 is provided within the receptacle 20 so as to partially protrude from the inner peripheral surface that extends from the insertion hole 22 of the receptacle 20.
There are no particular limitations on the positioning of the foreign matter removal member 26 within the receptacle 20, provided, as described above, the foreign matter removal member 26 is closer to the insertion hole 22 than the second O-ring 28. However, in terms of enabling removal of foreign matter from the tip and surface of the nozzle 10 during insertion of the nozzle 10, the foreign matter removal member 26 is most preferably positioned in the vicinity of the insertion hole 22 of the receptacle 20, adjacent to, and downstream from, the first O-ring 24, although may be provided favorably at any position between the first O-ring 24 and the second O-ring 28. From the ultimate viewpoint of preventing the adhesion of foreign matter to the second O-ring 28, the foreign matter removal member 26 may also be positioned upstream from, and immediately adjacent to, the second O-ring 28.
A description of the foreign matter removal operation by the gas supply structure of the first embodiment is presented below with reference to
The nozzle 10 and the receptacle 20 in this embodiment are formed of metal, and from the viewpoints of workability and strength, are preferably formed of stainless steel or the like.
On the other hand, the material of the foreign matter removal member 26 in the present embodiment may be any material having sufficient elasticity and/or flexibility to prevent damage to the surface of the nozzle 10 during sliding contact. Examples of materials that may be used include rubbers and flexible resins, and the use of polytetrafluoroethylene (PTFE) is preferred.
Furthermore, the foreign matter removal member 26 may be provided on the inner peripheral surface of the receptacle 20 as either a single continuous ring or as a non-continuous ring, and the portion of the foreign matter removal member 26 protruding from the inner peripheral surface may be either a blade-like form or a brush-like form. Further, the length of the protruding portion may be selected appropriately in accordance with the degree of elasticity or flexibility of the selected foreign matter removal member 26.
Moreover, the foreign matter removal member 26 preferably has a sliding resistance, determined on the basis of a pull-out load measurement, that is not less than 300 N and not more than 500 N. Ensuring a sliding resistance that satisfies this range means that when the foreign matter removal member 26 slides against the surface of the nozzle 10 during insertion of the nozzle 10, the nozzle 10 suffers no damage, while any foreign matter on the tip and surface of the nozzle 10 is able to be removed. The removal performance is particularly favorable when the foreign matter is water. For example, when a liquid fuel is used to fill a high-pressure hydrogen container (such as a tank), and the filling is conducted with the liquid fuel at a low temperature of approximately −40° C., any water on the surface of the nozzle 10 is removed by the foreign matter removal member 26 as the nozzle 10 is inserted into the receptacle 20, and therefore there is no possibility of water freezing on the second O-ring 28 where there is no gap between the nozzle 10 and the receptacle 20, meaning damage such as partial detachment of the second O-ring 28 can be prevented from occurring during connection and disconnection of the nozzle 10 and the receptacle 20.
Next is a description of an example of a gas supply structure according to a second embodiment of the present invention with reference to
In a more detailed description, the gas supply structure 200 according to the present embodiment comprises, in the case of the aforementioned Japanese proposed shape, a nozzle 30 having a gas supply passage 32, and a receptacle 40 having an insertion hole 42 into which the nozzle 30 is inserted to achieve connection, wherein the receptacle 40 is provided with a first O-ring 44 that is provided in the vicinity of the insertion hole 42 for the purpose of gas sealing, a second O-ring 38 is provided at the tip of the nozzle 30 for the purpose of gas sealing, and a portion of the second O-ring 38 is bonded to a recessed section provided near the tip of the nozzle 30 using a bonding material 37. The foreign matter removal member 36 is provided on the nozzle 30 in a position closer to the tip of the nozzle 30 than the second O-ring 38.
There are no particular limitations on the positioning of the foreign matter removal member 36 on the nozzle 30, provided, as described above, the foreign matter removal member 36 is closer to the tip of the nozzle 30 than the second O-ring 38. However, in terms of enabling removal of foreign matter on the inner peripheral surface of the receptacle 40 during insertion of the nozzle 30, the foreign matter removal member 36 is most preferably positioned in the vicinity of the tip of the nozzle 30, although in terms of preventing foreign matter adhesion to the second O-ring 38, may be provided favorably at any position adjacent to the second O-ring 38 and on the side of the tip of the nozzle 30.
A description of the foreign matter removal operation by the gas supply structure of the second embodiment is presented below with reference to
In a similar manner to that described above for the first embodiment, the nozzle 30 and the receptacle 40 in the second embodiment are formed of a metal such as stainless steel. Furthermore, in a similar manner to that described above for the first embodiment, the material of the foreign matter removal member 36 may be any material having sufficient elasticity and/or flexibility to prevent damage to the surface of the receptacle 40 during sliding contact. Examples of materials that may be used include rubbers and flexible resins, and the use of polytetrafluoroethylene (PTFE) is preferred.
Furthermore, the foreign matter removal member 36 may be provided on the surface of the nozzle 30 as either a single continuous ring or as a non-continuous ring, the portion of the foreign matter removal member 36 protruding from the surface of the nozzle 30 may be either a blade-like form or a brush-like form, and the length of the protruding portion may be selected appropriately in accordance with the degree of elasticity or flexibility of the selected foreign matter removal member 36.
Moreover, in a similar manner to that described above for the first embodiment, the foreign matter removal member 36 preferably has a sliding resistance, determined on the basis of a pull-out load measurement, that is not less than 300 N and not more than 500 N. Ensuring a sliding resistance that satisfies this range means that when the foreign matter removal member 36 slides against the inner peripheral surface of the receptacle 40 during insertion of the nozzle 30, the receptacle 40 suffers no damage, while any foreign matter on the inner peripheral surface of the receptacle 40 is able to be removed. The removal performance is particularly favorable when the foreign matter is water. When a liquid fuel is used to fill a high-pressure hydrogen container (such as a tank) in the manner described above, and the filling is conducted with the liquid fuel at a low temperature of approximately −40° C., any water on the surface of the receptacle 40 is removed by the foreign matter removal member 36 on the nozzle 30, and therefore there is no possibility of water freezing on the second O-ring 38 where there is no gap between the nozzle 30 and the receptacle 40, meaning damage such as partial detachment of the second O-ring 38 can be prevented from occurring during connection and disconnection of the nozzle 30 and the receptacle 40.
An example of a gas supply structure according to a third embodiment of the present invention is illustrated in
In other words, by combining the filter 52 having a relatively small loss coefficient with the filter 54 having a relatively large loss coefficient, foreign matter within the gas supplied to the tank can be trapped more reliably, and the values of the differential pressure ΔPf and ΔPs before and after the filters 52 and 54 can be reduced compared with cases in which only a single filter is provided, and particularly the case in which only the filter 54 is provided, meaning blockages of the entire filtering system within the gas passage 50 can be inhibited.
Mesh-like filters may be used as the filter 52 having a small loss coefficient, and the distance between the wires that form the mesh-like filter is preferably approximately 0.2 mm, although the present invention is not limited to this value. Further, either a single filter 52 may be provided, or two or more filters may be used in combination. For example, as illustrated in
Sintered metal filters may be used as the filter 54 having a large loss coefficient, and a sintered metal filter having a pore size of approximately 5 μm is preferred, although the present invention is not limited to filters of this pore size.
Furthermore, the respective passage pore sizes for the filter 52 and the filter 54 can be selected appropriately in accordance with the gas pressure of the passing gas and the nature of the foreign matter incorporated within the gas.
Although the present invention has been described in detail above, the scope of the present invention is not limited to the specific configurations described above.
Furthermore, the detailed description, claims, drawings and abstract of the invention disclosed in Japanese Patent Application No. 2007-336307, filed on Dec. 27, 2007, are deemed to be incorporated in their entirety within the present application.
A gas supply structure of the present invention may be used within any application that is used for supplying a gas, but is particularly suited to high-pressure gas filling applications, and is ideal for the hydrogen filling connectors mounted in movable structures such as vehicles.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-336307 | Dec 2007 | JP | national |
This is a 371 national phase application of PCT/JP2008/072348 filed 9 Dec. 2008, claiming priority to Japanese Patent Application No. JP 2007-336307 filed 27 Dec. 2007, the contents of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2008/072348 | 12/9/2008 | WO | 00 | 6/22/2010 |
