CA2235300A1 - Motor vehicle tank - Google Patents
Motor vehicle tank Download PDFInfo
- Publication number
- CA2235300A1 CA2235300A1 CA002235300A CA2235300A CA2235300A1 CA 2235300 A1 CA2235300 A1 CA 2235300A1 CA 002235300 A CA002235300 A CA 002235300A CA 2235300 A CA2235300 A CA 2235300A CA 2235300 A1 CA2235300 A1 CA 2235300A1
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- CA
- Canada
- Prior art keywords
- filler pipe
- tank
- elastically deformable
- set forth
- fuel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K15/00—Arrangement in connection with fuel supply of combustion engines or other fuel consuming energy converters, e.g. fuel cells; Mounting or construction of fuel tanks
- B60K15/03—Fuel tanks
- B60K15/04—Tank inlets
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- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Cooling, Air Intake And Gas Exhaust, And Fuel Tank Arrangements In Propulsion Units (AREA)
Abstract
A motor vehicle tank has a filler pipe including a portion which is elastically deformable at least over a part of its periphery and which is such that in an unexpanded condition it represents a constriction in the filler pipe. The constriction can be at least reduced by elastic expansion of the elastically deformable portion in dependence on the amount of fuel flowing through the filler pipe. The filler pipe may extend into the interior of the tank.
Description
CA 0223~300 1998-04-20 The invention relates to a fuel tank for a motor vehicle.
When a fuel tank for a motor vehicle is filled with fuel, fuel which is already in the tank and which forms a gaseous phase above the level of the fuel in the tank is displaced by the liquid fuel as it flows into the tank. In that respect care is to be taken to ensure that only minimum amounts, if any, of the fuel present in the tank in the gaseous phase pass into the outside atmosphere. To deal with this aspect it is nowadays the usual practice for a fuel tank to be provided with an activated carbon filter (often referred to as the ACF) through which the gas mixture displaced from the tank by the rising level of liquid fuel therein flows. When that happens the hydrocarbons in the gas mixture are at least substantially adsorbed by the activated carbon of the filter, or another suitable filter material.
However it is still necessary to reckon on the possibility of at least a part of the gases which are present above the level of liquid fuel in the tank being displaced out of the tank through the filling connection and thus passing into the outside atmosphere. That is possible whenever the cross-section of the filler pipe is only incompletely filled with fuel in the filling operation in such a way that free cross-sectional areas, which are therefore not filled with fuel, remain in the filler pipe, with gases and vapors thus flowing through those unfilled cross-sectional regions in opposite relationship to the direction of flow of the fuel through the filler pipe into the fuel tank, whereby such gases and vapors can escape into the atmosphere. Consideration has admittedly already been given to countering that possibility by the provision in the filler pipe of sleeves or the like consisting of elastic material, which are intended to bear sealingly against the outside peripheral surface of the fuel pump dispensing nozzle assembly and thus close off the cross-section which is not filled by the latter. It has been found however that this configuration cannot provide an effective sealing effect in the long term, not least also having regard to any wear which occurs.
The endeavour has admittedly generally been made to extend the filler pipe as far as possible into the tank in order to minimise the spacing between the end of the filler pipe from which the fuel issues and the bottom of the tank as, at the moment at which that lower end CA 0223~300 1998-04-20 of the filler pipe is entirely beneath the surface of the liquid fuel in the tank, the lower opening of the filler pipe is thus closed by the liquid fuel and accordingly no gases can pass into the filler pipe at the lower end thereof. In many cases however for practical reasons it is not possible for the filler pipe to be arranged to terminate so closely above the bottom of the fuel tank that this would prevent or at least adequately reduce the flow of gaseous fuel into the filler pipe through the lower opening thereof. The considerations which make it seem desirable for the filler pipe not to be arranged to terminate immediately above the bottom of the tank include the flow resistance which occurs in the filling operation and which increases with a decreasing distance between the lower end of the filler pipe and the oppositely disposed wall portion of the tank, for example therefore the tank bottom. Furthermore the design of motor vehicle fuel tanks which in many cases is of an extremely complicated configuration makes it virtually impossible for the end of the filler pipe to be arranged at such a short spacing from the tank bottom that the above-indicated problems would not occur or would occur only to a negligible extent.
In accordance with the present invention there is provided a 20 fuel tank for a motor vehicle, including a filler pipe comprising a portion which is elastically deformable at least over a part of its periphery and which is such that in an unexpanded condition it represents a constriction in the filler pipe.
As will be seen from the description hereinafter of preferred 25 embodiments of the fuel tank according to the invention, the motor vehicle fuel tank is designed in such a way that the discharge flow of gas mixture through the filler pipe during a filling operation can be at least substantially avoided, even when only a small amount of fuel per unit of time flows through the filler pipe in the filling 30 operation. The fuel tank thus affords a reliable but simple structure for at least substantially reducing the escape of fuel vapor from the tank during a tank-filling procedure, wherein the tank can be produced in a simple and inexpensive manner. Thus the invention is based on the consideration that, even when a small amount of fuel is flowing 35 through the filler pipe into the tank per unit of time, the cross-section of the filler pipe is entirely filled with fuel, at least in the above-mentioned constricted region thereof. Empirical values CA 0223~300 1998-04-20 indicate that it is readily possible for the magnitude of the cross-section available for the flow of liquid fuel in the constricted region of the filler pipe to be so selected that that cross-section is completely filled, even when only relatively small amounts of fuel are flowing through the filler pipe per unit of time, whereby the small amount of fuel flowing through the filler pipe is sufficient to produce what is referred to as a liquid seal. On the other hand however that reduced cross-sect:ional region of the filler pipe does not represent a flow resistance such as to impede the operation of 10 introducing liquid fuel into the tank during the tank-filling procedure as it is readily possible for the elasticity of the material defining the constricted cross-sectional region to be so selected that it automatically expands under the effect of the kinetic energy involved in the flow of fuel flowing in the filler pipe, more 15 specifically in accordance with the amount of fuel per unit of time, so that under all circumstances and even in the event of fluctuations in the feed flow of fuel the invention ensures that the cross-ssection of the filler pipe is always completely filled with liquid fuel at least in the portion which is c:onstricted in the non-loaded condition 20 thereof.
Advantageously, at least the portion of the filler pipe which involves the constricted cross-section is made from plastic material, while it is also readily possible for the entire filler pipe to be integrally formed from plastic material.
Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which:
Figure 1 is a diagrammatic view of a fuel tank for a motor vehicle, Figure 2 is a side view of a portion of the filler pipe of 30 reduced cross-section, Figure 3 shows a plan view of the portion illustrated in Figure 2, Figure 4 is a view in section taken along line IV-IV in Figure 3, Figure 5 is a view corresponding to Figure 2 of a second embodiment, Figure 6 is a view corresponding to Figure 3 of the second CA 0223~300 1998-04-20 embodiment, and Figure 7 is a view in section taken along line VII-VII in Figure 6.
Referring firstly to Figure 1, shown therein is a tank indicated generally by reference numeral 10 and provided with a filler pipe 14 which can be closed by means of a cap 12 and which, in the illustrated embodiment, projects into the internal space or interior 16 of the tank 10 to such an extent that the discharge opening for the fuel, at the lower end of the filler pipe 14, is disposed in the lower region of the internal space 16 of the tank 10. It will be noted that Figure 1 shows the tank in a highly simplified form and in a practical context the tank may be of a possibly highly complicated configuration, depending on the respective motor vehicle in which the tank is to be fitted. That applies in particular if the tank is made from plastic material, more especially a thermoplastic material.
The tank 10 is also provided at its top side with a venting connection 20 through which gases and vapors which are to be found in the tank 10 above the surface of the liquid fuel in the tank can escape when the tank is being filled. Reference numerals 19 and 20 denote respective possible positions of the surface of the liquid fuel in the tank.
An activated carbon filter (not shown) can be connected to the venting connection 20 for very substantially adsorbing the hydrocarbons and possibly also other substances which may escape from the tank, thereby to prevent such hydrocarbons and other substances from passing into the external atmosphere. Reference numeral 22 identifies a removal or drain conduit.
As soon as the surface of the liquid fuel in the tank 10 has reached a level at which the discharge opening 18 for the fuel is below the level of the surface of the liquid fuel, as is the case for example when the liquid fuel in the tank is at the level indicated by reference numeral 19 in Figure 1, no further gases and vapors can issue from the tank through the filler pipe 14. Until such a level of liquid fuel in the tank is reached however, that is to say, for example at the filling level as indicated by the level 21 in Figure 1, precautionary steps are to be t:aken in order to prevent fuel vapors and/or gases from issuing into the external atmosphere through the CA 0223~300 1998-04-20 filler pipe 14.
For that purpose, in its region which is within the tank 10, the filler pipe 14 is provided with a portion 24 of reduced diameter which comprises elastically easily deformable material and which at each end thereof is connected by way of a respective transitional region 26 to the respectively adjoining portions indicated at 28 for example in Figure 2, such portions 28 comprising rigid material.
It will be noted at this point that the terms used above in relation to the portions 24, 26 and 28 mean that the elastic material which forms the reduced-diameter portion 24 is on the one hand sufficiently flexible that, under the influence of the kinetic energy of the fuel flowing therethrough it can elastically expand, with an increase in the free cross-section thereof, or it can elastically contract with a decreasing amount of fuel flowing through the filler pipe per unit of time, in order thereby to adapt the size of the free cross-section therein for the flow of fuel therethrough to the respective amount of fuel per unit of time, whereby the entire cross-section is filled with liquid fuel. The latter thus forms the above-mentioned liquid seal, at least in that region which is of variable cross-section. In this arrangement, the transitional portions 26 are also made of elastically deformable material. It will be appreciated that the portions 28 which adjoin the transitional portions 26 and which have been referred to as rigid may also involve a certain degree of elastic deformability as is generally usual in relation to plastic pipes. The use of the term rigid here indicates that deformation does not occur under the effect of the forces which act on the filler pipe in normal operation, that is to say also under the effect of the forces which are to be attributed to the kinetic energy of the liquid fuel flowing through the filler pipe.
Reference will now be made to Figures 3 and 4 from which it can be seen in particular that the portion 24 of reduced diameter can be produced in a simple fashion by the region of the filler pipe 14, which includes the portion 24, being compressed in order thereby to produce in the constricted region a substantially elliptical cross-sectional shape, as can be seen more especially from Figure 4. That cross-sectional shape occurs when the portion 24 of the filler pipe is in a non-loaded or unexpanded condition. The free cross-section which CA 0223~300 1998-04-20 is afforded in that situation can readily be so selected that it approximately corresponds to the smallest amount of fuel flowing through the filler pipe per unit of time, that falls to be considered under practical operating circumstances, for example between 13 and 15 liters per minute. The actual size of the cross-section that must be afforded for that purpose can be established by simple tests. In the event of an increase in the amount of fuel flowing through the filler pipe per unit of time, which with a normal filling rate is at a maximum between about 50 and 60 liters per minute, the kinetic energy 10 of the flow of fuel produces a corresponding automatic increase in the size of the cross-section in the portion 24 and possibly also the adjoining regions 26 so that the entire cross-section in that region is always completely filled with liquid.
The arrangement of the constricted region 24 in the filler pipe 14 should be so selected that it is sufficiently far away from the end of the fuel pump dispensing nozzle assembly which is fitted into the filler pipe 14. That distance is desirably to be so selected that on the one hand the flow of the jet of fuel into the filler pipe 14 expands the constricted region 24 to such an extent that there is no build-up of fuel in the filler pipe which can result in automatic shut-off of the dispensing nozzle assembly, while on the other hand the jet of fuel is no longer so vigorous that it can open the constricted region by partially acting thereon, without the liquid fuel filling the entire cross-section involved. Moreover the elasticity of the material forming the constricted region 24 is to be so selected that essentially the kinetic energy of the flowing fuel causes expansion of the constricted region 24 whose peripheral dimension does not change.
It will be seen from the foregoing description that the largest 30 possible cross-section corresponds to the lowest level of fuel flow per unit of time which occurs in practical operation and which is defined for example in appropriate regulations while the substantially round cross-section of the filler pipe 14, when the region 24 is in the condition of being elastically expanded to the maximum amount, corresponds to the largest amount of fuel flowing per unit of time or the resulting flow rate.
It will be noted that the filler pipe shown in Figures 2 CA 0223~300 1998-04-20 through 4 can be produced for example by a procedure wherein, in a continuous extrusion operation, the plastic materials involved, having different elastic properties, are sequentially extruded in such a way that a material which is easily elastically deformable after cooling and hardening is disposed in the constricted region 24 and the adjoining transitional regions 26 while the respective regions adjoining same comprise a material which is rigid in the above-described sense, after cooling and hardening. It is thus readily possible if necessary for the filler pipe to be produced in one piece in its entirety. The region 24 of reduced cross-section can be shaped in a simple manner by the filler pipe being pressed flat in that region 24 while still in a hot plastic condition so that the region 24 adopts the desired cross-sectional shape. That can be readily implemented in a controlled and reproducible manner for example when using supporting air which keeps the interior of the pipe when still in a hot plastic condition under a slightly increased pressure, for example in a blow molding mold.
It will be appreciated that it is equally possible for the filler pipe to be made up from a plurality of portions which are releasably or fixedly connected together. In that case the portion which has or forms the constriction in the filler pipe 14 and which is thus elastically expandable, can be produced in the form of a separate part whose end regions are adapted to correspond to the cross-section of the respectively adjoining filler pipe portions, being therefore normally circular. The stiffness required for connection to the respectively adjacent pipe portions can be achieved by suitable dimensioning of the wall thickness or gauge of the pipe portions. It is however also possible for that portion to be produced by sequential extrusion, that is to say by extruding materials involving different properties one after the other.
The portion of the filler pipe 14 which in the illustrated embodiment is disposed in the internal space 16 of the tank 10 is surrounded by a tubular holder 30 which can also be in the form of a grid or of a similar configuration and which is of an inside diameter that is larger than the outside diameter of the filler pipe 14 in the non-constricted region thereof. The holder 30 is intended to prevent the filler pipe 14 bending or buckling sharply downwardly under the CA 0223~300 1998-04-20 effect of its own weight, in the elastic portion 24, in such a way that the cross-section of the filler pipe at that location would be closed or deformed in such a fashion that satisfactory operation of the filler pipe and more specifically the constricted portion 24 thereof would no longer be ensured. For that purpose it may be advantageous to provide supports 25 which extend radially or in some other suitable fashion and which are disposed between the holder 30 and the rigid portion 28 which downwardly adjoins the constricted portion 24. Instead of individual supports 25 it is also possible to use an annular grid or lattice or the like as a support element.
Reference will now be made to Figures 5 through 7 showing a further embodiment in which parts that are the same as those of the embodiment described hereinbefore with reference to Figures 1 through 4 are denoted by the same references but increased by 100. The foregoing description of the embodiment of Figures 1 through 4 will therefore be borne in mind when considering this further embodiment of the invention.
The difference of substance between the two embodiments described herein is that, in the embodiment shown in Figures 5 through 7, the actual filler pipe 114 is rigid in its constricted portion 124 but is provided with first and second mutually oppositely disposed openings 132 which are therefore arranged in displaced relationship through 180~ in the peripheral direction of the filler pipe. As can be seen in particular from Figure 6 the openings 132 are of a substantially elliptical configuration in plan view. The major axis of the ellipse extends in the longitudinal direction of the filler pipe 114. The configuration afforded by the provision of the openings 132 can also be defined in such terms that, of the peripheral portion of the filler pipe 114, first and second mutually oppositely disposed limbs 134 remain in the region of the openings 132; the limbs 134 extend progressively increasing in width in both directions from a respective plane which extends transversely with respect to the longitudinal axis of the filler pipe and which extends along the minor axis of the ellipse in which the limbs 134 are each of their smallest width, until at the respective axial end of the openings 132 the limbs 134 blend into each other in order again to form the complete peripheral portion of the filler pipe.
CA 0223~300 1998-04-20 The filler pipe 114 is provided in the region of the openings 132 and extending axially somewhat beyond same with a sleeve portion which is indicated at 136 and which comprises a highly elastic material, for example polyurethane or silicone plastic material and which is of a tube-like or hose-like configuration. The inside diameter of the sleeve portion 136 is smaller in the unexpanded condition of the sleeve portion 136 than the outside diameter of the filler pipe 114 on which it is fitted. By virtue of its elastic deformability the sleeve portion 136 extends in the region of the two openings 132 along the boundary edges 138 thereof, with the consequence that the regions of the sleeve portion 136 which cover over the openings 132 form in the portion 124 a part of the structure defining the filler pipe 114, while those regions of the sleeve portion 136, as is readily apparent from Figure 5, are at a smaller spacing from the longitudinal axis 140 of the filler pipe 114 than the completely rigid regions 128 of the filler pipe 114, which adjoin the portion 124, whereby the cross-section of the filler pipe is reduced at that location. In this embodiment, the magnitude of the smallest flow cross-section through the filler pipe thus depends on the width of the limbs 134 in the region of the minor axis 142 of the respective elliptical openings 132.
The required sealing integrity as between the outer peripheral surface of the filler pipe 114 and the sleeve portion 136 can be easily achieved by the sleeve portion 136 being extended sufficiently far over the adjoining regions 128 of the filler pipe with the complete wall configuration extending in the peripheral direction thereof.
Therefore, in the embodiment of Figures 5 through 7, it is not a part of the actual filler pipe, which is possibly of an integral construction, that is expanded or contracted in dependence on the amount of fuel flowing through the filler pipe per unit of time, but rather it is the sleeve portion 136 which functions in that way.
It will be appreciated that the above-described embodiments of the invention have been set forth solely by way of example and illustration of the principles thereof and that various modifications and alterations may be made therein without thereby departing from the spirit and scope of the invention.
When a fuel tank for a motor vehicle is filled with fuel, fuel which is already in the tank and which forms a gaseous phase above the level of the fuel in the tank is displaced by the liquid fuel as it flows into the tank. In that respect care is to be taken to ensure that only minimum amounts, if any, of the fuel present in the tank in the gaseous phase pass into the outside atmosphere. To deal with this aspect it is nowadays the usual practice for a fuel tank to be provided with an activated carbon filter (often referred to as the ACF) through which the gas mixture displaced from the tank by the rising level of liquid fuel therein flows. When that happens the hydrocarbons in the gas mixture are at least substantially adsorbed by the activated carbon of the filter, or another suitable filter material.
However it is still necessary to reckon on the possibility of at least a part of the gases which are present above the level of liquid fuel in the tank being displaced out of the tank through the filling connection and thus passing into the outside atmosphere. That is possible whenever the cross-section of the filler pipe is only incompletely filled with fuel in the filling operation in such a way that free cross-sectional areas, which are therefore not filled with fuel, remain in the filler pipe, with gases and vapors thus flowing through those unfilled cross-sectional regions in opposite relationship to the direction of flow of the fuel through the filler pipe into the fuel tank, whereby such gases and vapors can escape into the atmosphere. Consideration has admittedly already been given to countering that possibility by the provision in the filler pipe of sleeves or the like consisting of elastic material, which are intended to bear sealingly against the outside peripheral surface of the fuel pump dispensing nozzle assembly and thus close off the cross-section which is not filled by the latter. It has been found however that this configuration cannot provide an effective sealing effect in the long term, not least also having regard to any wear which occurs.
The endeavour has admittedly generally been made to extend the filler pipe as far as possible into the tank in order to minimise the spacing between the end of the filler pipe from which the fuel issues and the bottom of the tank as, at the moment at which that lower end CA 0223~300 1998-04-20 of the filler pipe is entirely beneath the surface of the liquid fuel in the tank, the lower opening of the filler pipe is thus closed by the liquid fuel and accordingly no gases can pass into the filler pipe at the lower end thereof. In many cases however for practical reasons it is not possible for the filler pipe to be arranged to terminate so closely above the bottom of the fuel tank that this would prevent or at least adequately reduce the flow of gaseous fuel into the filler pipe through the lower opening thereof. The considerations which make it seem desirable for the filler pipe not to be arranged to terminate immediately above the bottom of the tank include the flow resistance which occurs in the filling operation and which increases with a decreasing distance between the lower end of the filler pipe and the oppositely disposed wall portion of the tank, for example therefore the tank bottom. Furthermore the design of motor vehicle fuel tanks which in many cases is of an extremely complicated configuration makes it virtually impossible for the end of the filler pipe to be arranged at such a short spacing from the tank bottom that the above-indicated problems would not occur or would occur only to a negligible extent.
In accordance with the present invention there is provided a 20 fuel tank for a motor vehicle, including a filler pipe comprising a portion which is elastically deformable at least over a part of its periphery and which is such that in an unexpanded condition it represents a constriction in the filler pipe.
As will be seen from the description hereinafter of preferred 25 embodiments of the fuel tank according to the invention, the motor vehicle fuel tank is designed in such a way that the discharge flow of gas mixture through the filler pipe during a filling operation can be at least substantially avoided, even when only a small amount of fuel per unit of time flows through the filler pipe in the filling 30 operation. The fuel tank thus affords a reliable but simple structure for at least substantially reducing the escape of fuel vapor from the tank during a tank-filling procedure, wherein the tank can be produced in a simple and inexpensive manner. Thus the invention is based on the consideration that, even when a small amount of fuel is flowing 35 through the filler pipe into the tank per unit of time, the cross-section of the filler pipe is entirely filled with fuel, at least in the above-mentioned constricted region thereof. Empirical values CA 0223~300 1998-04-20 indicate that it is readily possible for the magnitude of the cross-section available for the flow of liquid fuel in the constricted region of the filler pipe to be so selected that that cross-section is completely filled, even when only relatively small amounts of fuel are flowing through the filler pipe per unit of time, whereby the small amount of fuel flowing through the filler pipe is sufficient to produce what is referred to as a liquid seal. On the other hand however that reduced cross-sect:ional region of the filler pipe does not represent a flow resistance such as to impede the operation of 10 introducing liquid fuel into the tank during the tank-filling procedure as it is readily possible for the elasticity of the material defining the constricted cross-sectional region to be so selected that it automatically expands under the effect of the kinetic energy involved in the flow of fuel flowing in the filler pipe, more 15 specifically in accordance with the amount of fuel per unit of time, so that under all circumstances and even in the event of fluctuations in the feed flow of fuel the invention ensures that the cross-ssection of the filler pipe is always completely filled with liquid fuel at least in the portion which is c:onstricted in the non-loaded condition 20 thereof.
Advantageously, at least the portion of the filler pipe which involves the constricted cross-section is made from plastic material, while it is also readily possible for the entire filler pipe to be integrally formed from plastic material.
Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which:
Figure 1 is a diagrammatic view of a fuel tank for a motor vehicle, Figure 2 is a side view of a portion of the filler pipe of 30 reduced cross-section, Figure 3 shows a plan view of the portion illustrated in Figure 2, Figure 4 is a view in section taken along line IV-IV in Figure 3, Figure 5 is a view corresponding to Figure 2 of a second embodiment, Figure 6 is a view corresponding to Figure 3 of the second CA 0223~300 1998-04-20 embodiment, and Figure 7 is a view in section taken along line VII-VII in Figure 6.
Referring firstly to Figure 1, shown therein is a tank indicated generally by reference numeral 10 and provided with a filler pipe 14 which can be closed by means of a cap 12 and which, in the illustrated embodiment, projects into the internal space or interior 16 of the tank 10 to such an extent that the discharge opening for the fuel, at the lower end of the filler pipe 14, is disposed in the lower region of the internal space 16 of the tank 10. It will be noted that Figure 1 shows the tank in a highly simplified form and in a practical context the tank may be of a possibly highly complicated configuration, depending on the respective motor vehicle in which the tank is to be fitted. That applies in particular if the tank is made from plastic material, more especially a thermoplastic material.
The tank 10 is also provided at its top side with a venting connection 20 through which gases and vapors which are to be found in the tank 10 above the surface of the liquid fuel in the tank can escape when the tank is being filled. Reference numerals 19 and 20 denote respective possible positions of the surface of the liquid fuel in the tank.
An activated carbon filter (not shown) can be connected to the venting connection 20 for very substantially adsorbing the hydrocarbons and possibly also other substances which may escape from the tank, thereby to prevent such hydrocarbons and other substances from passing into the external atmosphere. Reference numeral 22 identifies a removal or drain conduit.
As soon as the surface of the liquid fuel in the tank 10 has reached a level at which the discharge opening 18 for the fuel is below the level of the surface of the liquid fuel, as is the case for example when the liquid fuel in the tank is at the level indicated by reference numeral 19 in Figure 1, no further gases and vapors can issue from the tank through the filler pipe 14. Until such a level of liquid fuel in the tank is reached however, that is to say, for example at the filling level as indicated by the level 21 in Figure 1, precautionary steps are to be t:aken in order to prevent fuel vapors and/or gases from issuing into the external atmosphere through the CA 0223~300 1998-04-20 filler pipe 14.
For that purpose, in its region which is within the tank 10, the filler pipe 14 is provided with a portion 24 of reduced diameter which comprises elastically easily deformable material and which at each end thereof is connected by way of a respective transitional region 26 to the respectively adjoining portions indicated at 28 for example in Figure 2, such portions 28 comprising rigid material.
It will be noted at this point that the terms used above in relation to the portions 24, 26 and 28 mean that the elastic material which forms the reduced-diameter portion 24 is on the one hand sufficiently flexible that, under the influence of the kinetic energy of the fuel flowing therethrough it can elastically expand, with an increase in the free cross-section thereof, or it can elastically contract with a decreasing amount of fuel flowing through the filler pipe per unit of time, in order thereby to adapt the size of the free cross-section therein for the flow of fuel therethrough to the respective amount of fuel per unit of time, whereby the entire cross-section is filled with liquid fuel. The latter thus forms the above-mentioned liquid seal, at least in that region which is of variable cross-section. In this arrangement, the transitional portions 26 are also made of elastically deformable material. It will be appreciated that the portions 28 which adjoin the transitional portions 26 and which have been referred to as rigid may also involve a certain degree of elastic deformability as is generally usual in relation to plastic pipes. The use of the term rigid here indicates that deformation does not occur under the effect of the forces which act on the filler pipe in normal operation, that is to say also under the effect of the forces which are to be attributed to the kinetic energy of the liquid fuel flowing through the filler pipe.
Reference will now be made to Figures 3 and 4 from which it can be seen in particular that the portion 24 of reduced diameter can be produced in a simple fashion by the region of the filler pipe 14, which includes the portion 24, being compressed in order thereby to produce in the constricted region a substantially elliptical cross-sectional shape, as can be seen more especially from Figure 4. That cross-sectional shape occurs when the portion 24 of the filler pipe is in a non-loaded or unexpanded condition. The free cross-section which CA 0223~300 1998-04-20 is afforded in that situation can readily be so selected that it approximately corresponds to the smallest amount of fuel flowing through the filler pipe per unit of time, that falls to be considered under practical operating circumstances, for example between 13 and 15 liters per minute. The actual size of the cross-section that must be afforded for that purpose can be established by simple tests. In the event of an increase in the amount of fuel flowing through the filler pipe per unit of time, which with a normal filling rate is at a maximum between about 50 and 60 liters per minute, the kinetic energy 10 of the flow of fuel produces a corresponding automatic increase in the size of the cross-section in the portion 24 and possibly also the adjoining regions 26 so that the entire cross-section in that region is always completely filled with liquid.
The arrangement of the constricted region 24 in the filler pipe 14 should be so selected that it is sufficiently far away from the end of the fuel pump dispensing nozzle assembly which is fitted into the filler pipe 14. That distance is desirably to be so selected that on the one hand the flow of the jet of fuel into the filler pipe 14 expands the constricted region 24 to such an extent that there is no build-up of fuel in the filler pipe which can result in automatic shut-off of the dispensing nozzle assembly, while on the other hand the jet of fuel is no longer so vigorous that it can open the constricted region by partially acting thereon, without the liquid fuel filling the entire cross-section involved. Moreover the elasticity of the material forming the constricted region 24 is to be so selected that essentially the kinetic energy of the flowing fuel causes expansion of the constricted region 24 whose peripheral dimension does not change.
It will be seen from the foregoing description that the largest 30 possible cross-section corresponds to the lowest level of fuel flow per unit of time which occurs in practical operation and which is defined for example in appropriate regulations while the substantially round cross-section of the filler pipe 14, when the region 24 is in the condition of being elastically expanded to the maximum amount, corresponds to the largest amount of fuel flowing per unit of time or the resulting flow rate.
It will be noted that the filler pipe shown in Figures 2 CA 0223~300 1998-04-20 through 4 can be produced for example by a procedure wherein, in a continuous extrusion operation, the plastic materials involved, having different elastic properties, are sequentially extruded in such a way that a material which is easily elastically deformable after cooling and hardening is disposed in the constricted region 24 and the adjoining transitional regions 26 while the respective regions adjoining same comprise a material which is rigid in the above-described sense, after cooling and hardening. It is thus readily possible if necessary for the filler pipe to be produced in one piece in its entirety. The region 24 of reduced cross-section can be shaped in a simple manner by the filler pipe being pressed flat in that region 24 while still in a hot plastic condition so that the region 24 adopts the desired cross-sectional shape. That can be readily implemented in a controlled and reproducible manner for example when using supporting air which keeps the interior of the pipe when still in a hot plastic condition under a slightly increased pressure, for example in a blow molding mold.
It will be appreciated that it is equally possible for the filler pipe to be made up from a plurality of portions which are releasably or fixedly connected together. In that case the portion which has or forms the constriction in the filler pipe 14 and which is thus elastically expandable, can be produced in the form of a separate part whose end regions are adapted to correspond to the cross-section of the respectively adjoining filler pipe portions, being therefore normally circular. The stiffness required for connection to the respectively adjacent pipe portions can be achieved by suitable dimensioning of the wall thickness or gauge of the pipe portions. It is however also possible for that portion to be produced by sequential extrusion, that is to say by extruding materials involving different properties one after the other.
The portion of the filler pipe 14 which in the illustrated embodiment is disposed in the internal space 16 of the tank 10 is surrounded by a tubular holder 30 which can also be in the form of a grid or of a similar configuration and which is of an inside diameter that is larger than the outside diameter of the filler pipe 14 in the non-constricted region thereof. The holder 30 is intended to prevent the filler pipe 14 bending or buckling sharply downwardly under the CA 0223~300 1998-04-20 effect of its own weight, in the elastic portion 24, in such a way that the cross-section of the filler pipe at that location would be closed or deformed in such a fashion that satisfactory operation of the filler pipe and more specifically the constricted portion 24 thereof would no longer be ensured. For that purpose it may be advantageous to provide supports 25 which extend radially or in some other suitable fashion and which are disposed between the holder 30 and the rigid portion 28 which downwardly adjoins the constricted portion 24. Instead of individual supports 25 it is also possible to use an annular grid or lattice or the like as a support element.
Reference will now be made to Figures 5 through 7 showing a further embodiment in which parts that are the same as those of the embodiment described hereinbefore with reference to Figures 1 through 4 are denoted by the same references but increased by 100. The foregoing description of the embodiment of Figures 1 through 4 will therefore be borne in mind when considering this further embodiment of the invention.
The difference of substance between the two embodiments described herein is that, in the embodiment shown in Figures 5 through 7, the actual filler pipe 114 is rigid in its constricted portion 124 but is provided with first and second mutually oppositely disposed openings 132 which are therefore arranged in displaced relationship through 180~ in the peripheral direction of the filler pipe. As can be seen in particular from Figure 6 the openings 132 are of a substantially elliptical configuration in plan view. The major axis of the ellipse extends in the longitudinal direction of the filler pipe 114. The configuration afforded by the provision of the openings 132 can also be defined in such terms that, of the peripheral portion of the filler pipe 114, first and second mutually oppositely disposed limbs 134 remain in the region of the openings 132; the limbs 134 extend progressively increasing in width in both directions from a respective plane which extends transversely with respect to the longitudinal axis of the filler pipe and which extends along the minor axis of the ellipse in which the limbs 134 are each of their smallest width, until at the respective axial end of the openings 132 the limbs 134 blend into each other in order again to form the complete peripheral portion of the filler pipe.
CA 0223~300 1998-04-20 The filler pipe 114 is provided in the region of the openings 132 and extending axially somewhat beyond same with a sleeve portion which is indicated at 136 and which comprises a highly elastic material, for example polyurethane or silicone plastic material and which is of a tube-like or hose-like configuration. The inside diameter of the sleeve portion 136 is smaller in the unexpanded condition of the sleeve portion 136 than the outside diameter of the filler pipe 114 on which it is fitted. By virtue of its elastic deformability the sleeve portion 136 extends in the region of the two openings 132 along the boundary edges 138 thereof, with the consequence that the regions of the sleeve portion 136 which cover over the openings 132 form in the portion 124 a part of the structure defining the filler pipe 114, while those regions of the sleeve portion 136, as is readily apparent from Figure 5, are at a smaller spacing from the longitudinal axis 140 of the filler pipe 114 than the completely rigid regions 128 of the filler pipe 114, which adjoin the portion 124, whereby the cross-section of the filler pipe is reduced at that location. In this embodiment, the magnitude of the smallest flow cross-section through the filler pipe thus depends on the width of the limbs 134 in the region of the minor axis 142 of the respective elliptical openings 132.
The required sealing integrity as between the outer peripheral surface of the filler pipe 114 and the sleeve portion 136 can be easily achieved by the sleeve portion 136 being extended sufficiently far over the adjoining regions 128 of the filler pipe with the complete wall configuration extending in the peripheral direction thereof.
Therefore, in the embodiment of Figures 5 through 7, it is not a part of the actual filler pipe, which is possibly of an integral construction, that is expanded or contracted in dependence on the amount of fuel flowing through the filler pipe per unit of time, but rather it is the sleeve portion 136 which functions in that way.
It will be appreciated that the above-described embodiments of the invention have been set forth solely by way of example and illustration of the principles thereof and that various modifications and alterations may be made therein without thereby departing from the spirit and scope of the invention.
Claims (12)
1. A fuel tank for a motor vehicle, including a filler pipe comprising a portion which is elastically deformable at least over a part of its periphery and which is such that in an unexpanded condition it represents a constriction in the filler pipe.
2. A tank as set forth in claim 1 wherein the elastically deformable portion of the filler pipe has first and second ends, the filler pipe further includes a portion of rigid material adjoining at least one of the ends of the elastically deformable portion of the filler pipe, and the elastically deformable portion of the filler pipe is connected at at least its said one end to said adjoining portion of rigid material in integral relationship therewith.
3. A tank as set forth in claim 1 wherein said elastically deformable portion of the filler pipe is of an at least approximately elliptical cross-sectional shape.
4. A tank as set forth in claim 1 wherein the filler pipe includes a rigid portion having a peripheral surface with at least one opening therein, and the filler pipe further includes a sleeve portion of elastic material disposed around said rigid portion in a prestressed condition, said opening being of such a size and arrangement that the sleeve portion covering said opening projects at least in the non-loaded condition thereof into the cross-section of the filler pipe which is defined by the rigid portion adjoining same.
5. A tank as set forth in claim 4 wherein the filler pipe has first and second openings which are arranged in displaced relationship through 180°.
6. A tank as set forth in claim 1 wherein said filler pipe comprises thermoplastic material.
7. A tank as set forth in claim 4 wherein said sleeve portion comprises thermoplastic material.
8. A tank as set forth in claim 1 wherein said filler pipe is produced in one piece from different materials in such a way that a portion of rigid material adjoins at least one end of said elastically deformable portion.
9. A tank as set forth in claim 1 wherein said elastically deformable portion is produced in one piece from different materials in such a way that a portion of rigid material adjoins at least one end of said elastically deformable portion.
10. A tank as set forth in claim 9 wherein said elastically deformable portion is produced separately from the remainder of the filler pipe.
11. A tank as set forth in claim 1 wherein said filler pipe extends into the internal space of the tank.
12. A fuel tank for a motor vehicle comprising a tank body, and a filler pipe communicating with the tank body and including a portion which is elastically deformable over at least a part of its periphery, said elastically deformable portion in a rest condition thereof representing a constriction in the internal cross-section of the filler pipe and the elastically deformable portion being elastically expandable under an internal force in said filler pipe to at least reduce said constriction in the filler pipe.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19716812A DE19716812A1 (en) | 1997-04-22 | 1997-04-22 | Motor vehicle tank |
| DE19716812.4 | 1997-04-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2235300A1 true CA2235300A1 (en) | 1998-10-22 |
Family
ID=7827287
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002235300A Abandoned CA2235300A1 (en) | 1997-04-22 | 1998-04-20 | Motor vehicle tank |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0873900B1 (en) |
| CA (1) | CA2235300A1 (en) |
| DE (2) | DE19716812A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8490812B2 (en) | 2008-04-24 | 2013-07-23 | Dr. Ing. H.C.F. Porsche Aktiengesellschaft | Fuel tank |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10047769A1 (en) * | 2000-09-27 | 2002-04-11 | Bayerische Motoren Werke Ag | Filler pipe for vehicle fuel tank has two straight sections linked by bend which has greater cross-sectional area than straight sections |
| DE10120542B4 (en) | 2001-04-26 | 2004-07-15 | Kautex Textron Gmbh & Co. Kg | Fuel tank |
| DE102014005720B4 (en) * | 2014-04-17 | 2016-01-28 | Audi Ag | Filling pipe, in particular tank filler pipe for a motor vehicle |
| DE102018118272A1 (en) * | 2018-07-27 | 2020-01-30 | Kautex Textron Gmbh & Co. Kg | Filler neck for unpressurized refueling shutdown and refueling and operating fluid container with filler neck |
| DE102021108805B4 (en) | 2021-04-08 | 2023-05-04 | Bayerische Motoren Werke Aktiengesellschaft | INFLATION DEVICE FOR A VEHICLE AND VEHICLE WITH SUCH INFLATION DEVICE |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE7601633U1 (en) * | 1900-01-01 | Adam Opel Ag, 6090 Ruesselsheim | ||
| US4008831A (en) * | 1972-11-20 | 1977-02-22 | Jacques Vidilles | Safety reservoir for hydrocarbons and dangerous liquids |
| IT1260665B (en) * | 1993-07-26 | 1996-04-22 | Ergom Materie Plastiche Spa | UNION GROUP FOR A FUEL TANK, PARTICULARLY OF A VEHICLE |
| GB2283011A (en) * | 1993-10-16 | 1995-04-26 | Rover Group | Tank filler duct |
| JP3592398B2 (en) * | 1995-03-29 | 2004-11-24 | 株式会社パイオラックス | Filler tube structure |
| FR2741014B1 (en) * | 1995-11-15 | 1998-01-09 | Peugeot | DECEPTING DEVICE FOR THE FUEL CONDUIT OF A MOTOR VEHICLE |
-
1997
- 1997-04-22 DE DE19716812A patent/DE19716812A1/en not_active Withdrawn
-
1998
- 1998-04-07 DE DE59802289T patent/DE59802289D1/en not_active Expired - Lifetime
- 1998-04-07 EP EP98106331A patent/EP0873900B1/en not_active Expired - Lifetime
- 1998-04-20 CA CA002235300A patent/CA2235300A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8490812B2 (en) | 2008-04-24 | 2013-07-23 | Dr. Ing. H.C.F. Porsche Aktiengesellschaft | Fuel tank |
Also Published As
| Publication number | Publication date |
|---|---|
| DE59802289D1 (en) | 2002-01-17 |
| EP0873900A3 (en) | 1999-08-11 |
| EP0873900B1 (en) | 2001-12-05 |
| EP0873900A2 (en) | 1998-10-28 |
| DE19716812A1 (en) | 1998-10-29 |
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Legal Events
| Date | Code | Title | Description |
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| FZDE | Dead |