JP5193352B2 - Automotive fuel tank - Google Patents

Description

  The present invention relates to a vehicular fuel system in a broad sense, and more particularly to selectively connect or disconnect a fuel vapor ventilation system provided in a vehicular fuel tank to a fuel processing apparatus such as a fuel vapor processing apparatus. This relates to the switching valve.

  A fuel vapor shut-off connection for a fuel tank or its refueling system is known, for example, from US Pat. Patent Document 1 discloses a shutoff connection body for a fuel pipe of an automobile fuel tank, and this known shutoff connection body is located in a fuel supply passage to the fuel tank so as to switch a vent valve of the fuel tank at the time of fueling. A flap that is displaced, a first compensation chamber connected to the vent valve for venting in the tank during refueling, and a connection to the vent valve for venting in the tank during normal operation other than during refueling A second compensation chamber, wherein the vent valve is in communication with the second compensation chamber and the fuel supply passage to the fuel tank when the fuel system is in normal operation. It is configured. This fuel vapor shut-off connection body has a switching function of selectively connecting the first compensation chamber to the fuel vapor filter or the fuel supply passage to the fuel tank by an open / close switching valve. It is characteristic in that it can be adapted to various fuel tank refueling systems.

  In the modification of the fuel tank refueling ventilation means described in Patent Document 1, the volume flow of gas generated in the tank when the vehicle is refueled is released into the atmosphere through the compensation chamber and the fuel vapor processing device. The flow path between the compensation chamber and the fuel vapor treatment device is a valve that shuts off the flow path when the vehicle is in a normal operating state and opens the flow path when fuel is being supplied to the fuel tank. A mechanism is provided. Therefore, in the ventilation system described in Patent Document 1, it is clear that ventilation in the tank is still performed in a conventional manner when the automobile fuel system is in a normal operating state.

  Conventionally, tank ventilation when the fuel system is in a normal operating state is generally performed by a ventilation system from a plurality of locations in the fuel tank to a fuel vapor treatment device through a series of operating ventilation conduits. . Typically, the vent on the fuel tank is located above the tank maximum allowable liquid fuel level and is closed by a float valve type vent valve. In order to prevent the fuel tank from being overfilled, these vent valves are provided with a pressure holding function or are provided with another pressure holding valve so that the on-off valve of the fuel nozzle is shut off at an appropriate time during refueling. .

  Therefore, it is necessary to provide a relatively large number of ventilation valves in accordance with the number of ventilation locations to be arranged in the fuel tank. In addition, since a float valve type ventilation valve has inertia in a valve body, It is inevitable that fuel leaks from the point or other vent points to the vent conduit. Even in the pressure holding valve attached to the vent valve, a certain amount of leakage is unavoidable. Therefore, as the number of vent portions increases, the risk of overfilling the fuel tank increases.

  In addition, it is necessary to keep the inside of the fuel tank in a non-pressure state substantially equal to atmospheric pressure during operation of the automobile.

  Patent Document 2 discloses a tank ventilation system for a fuel tank having a tank bulging portion, an oil supply pipe that can be closed by a cap, and a vent conduit and a vent valve connected to the tank bulging portion. The vent valve of this system can be switched to shut off the vent conduit when the filler plug is opened and to open the vent conduit when the filler plug is closed. Yes. For this switching, a shut-off valve interposed between the fuel vapor treatment device and the fuel tank vent conduit is attached to the fueling head of the fueling pipe, and in this case, a cap cap is screwed into the open end of the fueling pipe. And the shut-off valve is actuated, thereby opening the flow path from the vent conduit to the fuel vapor treatment device in operation.

  The tank aeration system described in Patent Document 2 is only adapted to the aeration system at the time of refueling according to the European standard system. In this case, the generated fuel vapor is sucked by a conforming device on the refueling nozzle gun side. In the tank ventilation system disclosed in Patent Document 2, the integration of tank ventilation at the time of refueling, which is achieved by the shutoff connection body according to Patent Document 1, is not embodied.

  Many patent documents describe fuel vapor control systems that include a switching valve attached to a fuel line to operate when a fuel nozzle is inserted. Examples of such patent documents are as follows.

  That is, Patent Document 3 discloses a fuel provided with a ventilation shutoff valve having a first chamber connected to a ventilation tube, a second chamber communicating with a canister, and a third chamber connected to an evaporation tube. A tank is disclosed. The first chamber and the second chamber are defined by a first partition wall having a first communication hole, and the second chamber and the third chamber are defined by a second partition wall having a second communication hole. ing. The main valve body of the ventilation cutoff valve is arranged in the second chamber so that the first communication hole is opened when the shutter pushes the main valve body of the ventilation cutoff valve. The main valve body of the ventilation cutoff valve is provided with a check valve, and is biased toward the second partition wall by an elastic member interposed between the check valve and the valve body of the ventilation cutoff valve. The second communication hole is closed.

  亦 Patent Document 4 discloses an on-board fuel vapor recovery system for refueling formed by individual switching paths inserted into a pressure balance line. When the switching valve is switched between the fueling mode and the operation mode, the individual switching path of the pressure balance line is switched, and in the operation mode, the pressure balance line is connected to the fuel vapor storage section via the switching valve outlet, In mode, the pressure balance line is shut off. The system can also incorporate a rollover valve, in which case the rollover valve is preferably connected to a small diameter pressure balancing duct having a refueling ventilation line. This refueling ventilation line is opened by the operation of the switching valve when the refueling nozzle is inserted into the refueling port of the fuel tank, but is shut off when the refueling nozzle is removed, and the refueling ventilation line, the pressure equilibrium line, Only the small-diameter pressure balancing duct leads from the switching valve outlet to the steam accommodating portion.

  In Patent Document 5, a fuel tank, an oil supply pipe connected to the tank, a shutter mechanism that is disposed in the oil supply pipe and operates when the oil supply nozzle is inserted, and the inserted oil supply nozzle toward the shutter mechanism are disclosed. A guide provided in the oil supply pipe for guiding the fuel, a lever arranged in the oil supply pipe so as to incline over a certain angle by abutting with a fuel supply nozzle guided by the shutter mechanism in the oil supply pipe, and a fuel A fuel tank system is disclosed that includes a fuel vapor vent mechanism that includes an on / off valve responsive to the tilting motion of the lever to form a communication flow path between the tank and an associated mechanism such as a canister. Here, the lever is disposed between the guide and the shutter mechanism. The on / off valve is slidable on the inner surface of the cylinder in the housing case, and the inner surface of the cylinder is provided with a plurality of raised ridges or ridges extending in the axial direction, thereby smoothly sliding the on / off valve. And enables fuel vapor to flow as much as possible when the on / off valve is opened.

  Another fuel vapor control system including a switching valve attached to the fuel supply pipe is also disclosed in Patent Document 6, for example.

German Patent Application Publication No. 1847472 German Patent Application Publication No. 19540267 US Pat. No. 5,404,906 US Pat. No. 5,983,963 U.S. Pat. No. 4,941,587 US Pat. No. 6,318,423

  Accordingly, it is an object of the present invention to provide an improved fuel tank including a fuel vapor control system that operates easily and reliably in conjunction with a switching valve attached to a fuel line to operate in abutment with a fuel nozzle. It is to be. Another object of the present invention is to enable the fuel tank to be vented at a pressure-free state substantially equal to atmospheric pressure during the operation of the automobile, and to collect condensed droplets from fuel vapor, which is another requirement. It is to provide a fuel tank that can be made as simple and inexpensive as possible, taking into account each volume for pressure compensation.

  Another object of the present invention is to provide an improved switching valve for a fuel system having a configuration capable of eliminating an additional container for removing condensed droplets of fuel vapor and an additional volume for pressure compensation. Is still another object of the present invention.

  The fuel tank for automobiles according to the present invention comprises an oil supply pipe that forms a tank oil supply passage, an operation ventilation conduit connected to the oil supply head of the oil supply pipe, and an oil supply ventilation conduit, and the oil supply head has at least one open / close switching function. A valve is provided. The switching valve opens a connection channel between the ventilation conduit and the ventilation channel leading to the fuel vapor processing apparatus at the first switching position (fueling position) and connects the ventilation conduit and the tank oil supply channel during operation. In the second switching position (operating position), the connection passage between the ventilation conduit and the tank oil supply passage is opened and the connection passage between the ventilation conduit and the ventilation passage is closed. The open / close switching valve allows the operation-time ventilation conduit to be connected to the ventilation channel, and the switching valve opens the connection channel between the operation-time ventilation conduit and the ventilation channel at the second switching position, and the first switching channel. In the switching position, the connection flow path between the ventilation conduit and the ventilation flow path at the time of operation is cut off, and further, the liquid fuel drain passage connected to the tank fuel supply passage is connected to the fuel vapor processing apparatus from the ventilation conduit at the time of operation. Is provided.

  The liquid fuel drain passage is preferably configured such that liquid fuel in which the fuel vapor is condensed or liquid fuel droplets accompanying the fuel vapor flows out into the tank oil supply passage only by the action of gravity.

  According to one embodiment of the invention, the refueling head comprises a liquid trap for liquid fuel to be discharged to the tank refueling passage.

  It is particularly advantageous if the liquid trap comprises a compartment. The compartment of the liquid trap is integrated in the housing of the switching valve.

  According to one embodiment of the present invention, the liquid trap comprises sealing means for sealing the compartment to prevent drainage under certain specific circumstances.

  It is particularly preferred that the liquid trap comprises a seal plug that is displaceable between an open position for discharging liquid fuel from the compartment and a closed position for preventing discharge.

  The switching valve according to the present invention preferably includes a fueling nozzle sensor for selectively connecting the operating ventilation conduit and the refueling ventilation conduit to a fuel vapor treatment device (activated carbon filled canister).

  In the fuel tank according to the present invention, the refueling ventilation conduit can be connected to the refueling head without interposing a droplet removal container or a compensation chamber. Thus, an additional container for removing condensed vapor vapor droplets and an additional volume for pressure compensation are not required.

  In the second switching position of the on-off switching valve, the venting conduit is preferably connected to the fuel vapor treatment device so that it opens without pressure. Here, in the present invention, the term “no pressure” means a state in which a pressure loss is caused only by the flow path cross-sectional area of the conduit and the fluid resistance of the fuel vapor processing apparatus.

  It is particularly preferable that a recirculation flow path in the form of an opening or a passage leading to the tank fuel supply passage is formed in the connection flow path between the fuel supply ventilation conduit and the fuel vapor processing apparatus.

  As a result, part of the gas discharged from the tank during refueling to the tank is recirculated through light oil in the tank refueling passage to avoid excessive delivery of hydrocarbon-containing gas to the fuel vapor processing apparatus. be able to.

  In a fuel tank according to another embodiment of the present invention, when the fuel in the tank flows backward to the fuel supply pipe between the tank fuel supply passage and the vent flow path, at least a roll that shuts off the connection flow path to the fuel vapor processing apparatus An over valve is provided, so that it is possible to reliably prevent excess fuel from overflowing from the fuel supply pipe to the fuel vapor processing apparatus and the surroundings, particularly when the vehicle rolls over.

  According to yet another embodiment of the present invention, one or more refueling restriction vent valves (FLVV) for determining the maximum fuel level in the fuel tank, i.e., the fuel level at which refueling nozzle cut-off or shut-off occurs. Is provided in the fuel tank.

  Thus, it is advantageous to associate the refueling operation with the state of each vent valve during refueling. The vent valve can be controlled in other ways. For example, a pressure differential, a liquid level in the fuel tank, or an actuating plunger actuated by a fueling nozzle can be used.

  A fuel tank according to still another embodiment of the present invention is attached to a fuel supply pipe, a fuel vapor processing device such as a fuel vapor filter (activated carbon filled canister), at least one first valve, and a fuel supply head of the fuel supply pipe. And a switching valve having a fueling nozzle sensor for selectively shutting off the first valve from the fuel vapor processing device in accordance with the presence or absence of the fueling nozzle in the fueling head. The first valve in this case may be a fuel discharge valve, and a fuel supply restriction valve (FLV) may be added as the second valve. The system may be configured such that the switching valves selectively disconnect these valves from the fuel vapor treatment device.

  Here, the term “alternative” means that at least one of the first valve and the at least one second valve is connected to the fuel vapor processing apparatus in flow path simultaneously with the shutoff or disconnection. Used to mean.

  The present invention further provides a switching valve attached to a fueling head of a fueling pipe leading to a fuel tank, the switching valve comprising a first valve inlet port, a second valve inlet port, a fuel valve A housing having a vapor chamber, a fuel vapor outlet port communicating with the fuel vapor chamber, and a seal member connected to a fuel nozzle sensor that is spring-biased so as to protrude into the fuel head is provided. The seal member can be displaced so as to block the fluid flow from the first valve inlet port to the fuel vapor chamber depending on whether or not a fuel nozzle is present in the fuel head. A liquid trap for collecting liquid fuel from fuel vapor flowing into the housing from one valve inlet port and / or the second valve inlet port and guiding the liquid fuel into the refueling head is integrally provided. .

  This switching valve is particularly preferably capable of alternatively connecting the first valve inlet port or the second valve inlet port to the fuel vapor processing apparatus.

  According to a preferred embodiment of the switching valve according to the invention, the fueling nozzle sensor comprises a plunger mounted on the housing, the plunger retracting when the fueling nozzle inserted in the fueling head abuts. During normal times, the spring is biased so as to protrude from the housing into the oil supply head of the oil supply pipe.

  According to another preferred embodiment of the switching valve according to the invention, the liquid trap is between a compartment having an outlet opening leading to a drain port connected to the fueling head and between a closed position and a normal open position. A seal plug that is displaceable, wherein the seal plug closes the outlet opening in the closed position and opens the outlet opening in the open position to pass through the drain port from the compartment into the oil supply head. The liquid fuel can be discharged.

  According to yet another preferred embodiment of the switching valve according to the invention, the seal plug is displaceable along a substantially longitudinal axis.

  According to still another preferred embodiment of the switching valve according to the present invention, the seal member comprises a disk-like part connected to the oil supply nozzle sensor, and the first valve inlet port has a first seal valve seat. The second valve inlet port communicates with a second chamber coaxially surrounding the first chamber, the second chamber has a second seal valve seat, and the disc-shaped component. The seal member made of can be alternatively seated on the first seal valve seat and the second seal valve seat. This configuration is a structure in which the compartment of the liquid trap communicates with the second chamber leading to the second valve inlet port.

  The liquid trap compartment preferably communicates with a second valve inlet port, i.e., a second chamber in communication with an oil supply restriction valve (FLV) inlet port.

  Compared with the prior art, in the fuel tank according to the present invention, it is not necessary to add a pressure holding valve to each ventilation point provided at various positions of the fuel tank, and therefore the intake pipe can be directly connected to the fuel vapor processing apparatus. In this case, it is possible to receive the advantage that ventilation to the atmosphere can be performed alternatively via the fuel vapor processing apparatus during refueling and during operation.

It is the schematic of the fuel system for vehicles equipped with the switching valve by this invention. It is a rear view of the oiling head part of the oiling pipe neck which attached the switching valve. It is a perspective view of the switching valve by this invention. It is a perspective view of the oil supply head part which attached the oil supply nozzle and the plunger for sensors with the perspective view, and the switching valve attached to it. It is an AA line arrow sectional view of Drawing 2B which shows the inside of a change-over valve in an open position except at the time of refueling. It is a BB line arrow sectional view of Drawing 2B which shows the inside of the change-over valve in the open position except at the time of refueling. It is a perspective sectional view corresponding to FIG. 3A. It is an AA arrow directional cross-sectional view of FIG. 2B which shows the inside of the switching valve in the closed position at the time of refueling. It is a BB line arrow sectional view of Drawing 2B which shows the inside of the change-over valve in the closed position at the time of refueling. FIG. 4B is a perspective sectional view corresponding to FIG. 4A. It is arrow sectional drawing in another embodiment of the switching valve by this invention.

  In order to deepen the understanding of the present invention and to show that the present invention can actually be carried out, some embodiments that are not intended to limit the present invention will be described with reference to the accompanying drawings.

  First, paying attention to FIG. 1, a fuel system schematically shown by an overall reference numeral 8 includes a fuel tank 10, which is provided with a fuel supply pipe 12, and an end portion of the fuel supply pipe is a fuel supply nozzle of the fuel supply apparatus The end portion is a refueling head portion 14 (hereinafter sometimes referred to as a refueling pipe neck) that is adapted to receive a reference numeral 18 in FIG. 2C.

  A plurality of valve devices are also attached to the fuel tank 10, and some of them are schematically shown in FIG. That is, the outlet ports of a plurality of rollover valves (ROV) 20 mounted on the tank as vent valves are all connected to the tube 35, and this tube constitutes an operating vent conduit. This means that the fuel tank is vented during normal operation of the vehicle by an actuating vent conduit connecting a series of rollover valves 20. Each rollover valve is open when the vehicle is in normal operation. The fuel tank 10 is also equipped with an oil supply restriction vent valve (FLVV) 22. Although only one fuel supply restriction ventilation valve is shown in FIG. 1, two or more oil supply restriction ventilation valves may be attached to the fuel tank.

  The fuel system further includes a known fuel vapor processing device (fuel vapor filter) 26 such as an activated carbon filled canister.

  Each of the vent valves 20 and 22 and the fuel vapor processing device 26 are connected to a switching valve according to the present invention indicated by the general reference numeral 28 as described later.

  The switching valve 28 is fixedly attached to the oil supply pipe neck 14 in a substantially vertical orientation as will be apparent below (see FIGS. 2A and 2C).

  The switching valve 28 has a housing 32, which includes a rollover valve inlet port 34 that can be connected to one or more rollover valves 20 by a tube 35 that constitutes an operating ventilation conduit, and an oiling ventilation conduit. An oil supply restriction vent valve inlet port 36 which can be connected to one or more oil supply restriction ventilation valves 22 by a separate tube 42 is provided. The fuel vapor outlet port 38 provided in the housing is further connected to the fuel vapor processing device 26 by another tube constituting a vent outlet pipe.

  A fuel vapor chamber 50 communicating with the fuel vapor outlet port 38 is provided in the housing 32 of the switching valve 28.

  An ROV inlet chamber 52 is provided substantially concentrically in the fuel vapor chamber of the housing 32, and the rollover valve inlet port 34 communicates with the annular boundary seal 54 at the lower end of the ROV inlet chamber through the ROV inlet chamber. As will be described below, the seal is sealed when a seal member 58 that can be displaced in the axial direction of the housing is seated to block communication between the ROV inlet chamber and the fuel vapor chamber. Further, a fuel supply restriction vent valve chamber (FLVV chamber) 53 partitioned from the fuel vapor chamber by the seal member is provided in the housing, and a fuel supply restriction vent valve inlet port 36 communicates with the oil supply restriction vent valve chamber. In addition, an annular seal valve seat 59 for receiving the lower peripheral edge of the seal member is provided.

  Concentrically protruding from the lower part of the housing 32 is a fuel nozzle sensor in the form of a plunger 62, which is the end protruding from the lower part of the housing when attached to the fuel pipe neck 14 (FIG. 2A). The portion (FIGS. 3A to 3C) is spring-biased in the housing so as to collide with the oil supply nozzle 18 inserted into the oil supply pipe neck 14 and to be able to move backward.

  The seal member 58 is connected to the plunger 62 via a cracking spring, and is displaceable between a first switching position (closed position) and a second switching position (substantially open position). Here, the closed position is the tank fueling position (FIGS. 4A to 4C) when the fueling nozzle is inserted into the fueling pipe neck. When the seal member is in this position, the FLVV chamber 53 is the fuel vapor chamber 50. However, the ROV chamber inlet 52 is cut off from the fuel vapor chamber 50 and the FLVV chamber 53. The substantially open position is an operating position when the fuel system is in a normal operating state (FIGS. 3A to 3C). At this time, the ROV chamber inlet 52 communicates with the fuel vapor chamber 50, but the FLVV The chamber 53 is no longer isolated from the ROV inlet chamber 52 and the fuel vapor chamber 50. In the open position, as shown in FIG. 3C, the seal member 58 is seated on the seal valve seat 59 and seals the communication cutoff portion between the FLVV chamber and the fuel vapor chamber, whereby the fuel supply restriction vent valve inlet port 36 and the fuel vapor are sealed. Communication with the chamber 50 is blocked in a sealed state.

  Further, as shown in the figure, a condensing liquid fuel trap is incorporated in the switching valve 28, and this trap collects and collects the liquid and droplets of fuel condensed from the fuel vapor in the switching valve. It is provided to recirculate the liquid fuel into the refueling pipe neck. This liquid fuel trap comprises a liquid trap compartment 70 having an outlet opening 72, which is provided in the refueling pipe neck 14 (not shown) with the switching valve attached in the proper orientation. ) To the drain port 76.

  A cylindrical plug accommodating portion 82 is provided in the housing around the outlet opening 72, and a seal plug 80 having a certain mass is accommodated therein. The seal plug 80 is biased toward the outlet opening 72 by a coiled weak spring 86, but is normally easily movable to an open position, that is, a position where the outlet opening 72 is not closed. However, when the vehicle rolls over, the sealing plug 80 completely seals the outlet opening 72 due to the gravity acting on the mass of the sealing plug 80 and the urging by the coiled spring 86. Held in position.

  Here, the plug accommodating portion 82, and thus the seal plug 80, extends in parallel with the axis of the oil supply pipe 12 that is oriented substantially vertically when the vehicle is in a normal driving posture (FIG. 2A), so that, for example, a running vehicle It should be noted that the seal plug 80 is pushed to the closed position by inertial force even when it bounces up and down.

  When the vehicle is in a normal driving state, in other words, when the vehicle is not being refueled, the plunger 62 is always in the extended position, i.e., protruded into the refueling pipe neck 14, so that the plunger A seal member 58 that is slidably coupled via a spring is spaced from the annular boundary seal 54, whereby the ROV inlet chamber 52 communicates with the fuel vapor chamber 50 and fuel vapor treatment from one or more rollover valves 20. A flow of fuel vapor to the device 26 is ensured. However, in this state, the FLVV chamber 53 is cut off from the ROV inlet chamber 52 and the fuel vapor chamber 50, so that the fuel vapor from the ROV inlet chamber is directed to at least one fuel supply restriction vent valve (FLVV). Needless to say, the flow is prevented. The liquid and droplets of the fuel accumulated in the housing 32 are collected in the liquid trap compartment 70, and the collected liquid fuel flows out through the outlet opening 72 every time the seal plug 80 moves to the opening position. Then, it returns to the fuel tank 10 through the port 76 and finally into the fuel tank neck 14.

  However, when refueling, the refueling nozzle 18 of the refueling device is inserted into the refueling pipe neck 14 (FIG. 2C), and when the plunger 62 is pushed by this nozzle and reaches the retracted position, the seal member 58 moves around the annular boundary seal 54 all around. And thereby establishing communication between the FLVV chamber 53 and the fuel vapor chamber 50, thus preventing one or more to prevent excessive fuel supply (determine cut-off or shut-off level). Ventilation between the fuel supply restriction ventilation valve (FLVV) and the fuel vapor processing device 26 is promoted.

  FIG. 5 shows a modified embodiment of the present invention. In this case, the switching valve indicated by the general reference numeral 90 is similar in appearance to that described in the above-described embodiment, but the oil supply restriction vent valve inlet port 92 is The point is that it leads to an inlet chamber 94 having a base wall 96 that can be attached to the oil pipe neck (for example by heat welding), the base wall being provided with an opening 98 that communicates directly into the oil pipe neck. Yes. In this configuration, the fuel vapor entering the oil supply restriction ventilation valve inlet port 36 from the oil supply restriction ventilation valve (not shown) is sucked into the oil supply pipe neck due to a reduced pressure state generated in the oil supply pipe neck during fueling. This is a function that is required during refueling according to safety regulations. Therefore, with this configuration, fuel vapor generated during refueling can be sucked substantially into the fuel pipe neck and returned to the fuel tank without being led to a fuel vapor processing apparatus (not shown).

  Alternatively, the switching valve having the same structure as that of the above-described embodiment can be used to suck the fuel vapor during refueling from the refueling pipe neck into the tank. In this case, the second valve inlet port (Oil supply restriction vent valve inlet port 36) may be shut off with a seal plug (not shown), and the connection line (tube 42 in FIG. 1) from the oil supply restriction vent valve may be directly connected to the oil supply pipe neck. .

  As described above, the flow path connection structure in which at least one oil supply restriction vent valve communicates directly from the corresponding opening of the oil supply pipe neck into the oil supply pipe neck via the normally open flow path formed in the switching valve is provided in the fuel system. It is also suitable for use in vehicles equipped with an on-board diagnostic system (OBD) for testing and fault detection. In this case, when a certain reduced pressure state (typically vacuum) is applied to, for example, a fuel processing system, this reduced pressure state reaches the fuel tank from each vent valve attached to the fuel tank via the switching valve. Therefore, the switching valve according to the present invention does not interfere with the operation of the OBD. In other words, in the normal connection structure according to the prior art, a check valve is interposed between the fuel tank and the oil supply pipe neck, so that the balance of pressure between the tank and the oil supply pipe neck is prevented or disturbed. By providing such a switching valve according to the present invention, a communication flow path passing through the switching valve is established between the fuel supply pipe neck and the fuel tank, and therefore, the fuel supply pipe may have the same pressure as the fuel tank. it can.

  It is known that a large amount of air is brought into the fuel tank along with the fuel flow from the fuel nozzle during fueling. In order to reduce the adverse effects of this phenomenon, it is known to circulate the incoming air, ie to return excess air through the air tube. In such a case, if a flow path is formed through the switching valve according to the present invention, the air brought into the fuel tank passes through the communication flow path. As a result, the amount of air brought into the fuel tank during refueling can be reduced without providing a special air tube.

  Although several embodiments have been shown and described above, this is not intended to limit the disclosure scope of the present invention by each embodiment, but rather to the appended claims with the necessary modifications. It should be understood that the present invention is intended to cover all embodiments and variations that fall within the spirit and scope of the invention as described.

Claims (9)

A switching valve mounted on a fueling head of a fueling pipe that leads to a fuel tank,
A first valve inlet port, a second valve inlet port, a fuel vapor chamber, a fuel vapor outlet port communicating with the fuel vapor chamber, and a fuel-biased nozzle sensor spring-biased so as to protrude into the fueling head A housing having a seal member to be coupled,
The seal member is displaceable to block the fluid flow from the first valve inlet port to the fuel vapor chamber depending on whether or not a fuel nozzle is present in the fuel head.
A liquid trap for collecting liquid fuel from the fuel vapor flowing into the housing from the first valve inlet port and / or the second valve inlet port and guiding the liquid fuel into the refueling head in the housing. Is a monolithic valve.   The switching valve according to claim 1, wherein the first valve inlet port or the second valve inlet port can be alternatively connected to the fuel vapor processing apparatus.   The lubrication nozzle sensor is composed of a plunger mounted on the housing, and the plunger protrudes from the housing into the lubrication head of the lubrication pipe so that the plunger moves backward when the lubrication nozzle inserted into the lubrication head comes into contact. The switching valve according to claim 1, wherein the switching valve is spring-biased.   The liquid trap comprises a compartment having an outlet opening leading to a drain port connected to the refueling head, and a seal plug displaceable between a closed position and a normal open position, the seal plug comprising the closure plug The outlet opening is closed at the position, and the outlet opening is opened at the open position so that the liquid fuel can be discharged from the compartment into the fueling head through the drain port. The switching valve according to claim 1.   5. A switching valve according to claim 4, wherein the seal plug is displaceable along a substantially longitudinal axis.   The seal member is composed of a disk-like component connected to the oil supply nozzle sensor, the first valve inlet port communicates with the first chamber having the first seal valve seat, and the second valve inlet port is the first valve. The second chamber has a second seal valve seat that communicates with a second chamber that coaxially surrounds the chamber, and the seal member made of the disk-shaped component includes the first seal valve seat and the second seal valve. The switching valve according to claim 1, wherein the switching valve can be alternatively seated on the seat.   2. A switching valve according to claim 1, wherein the compartment of the liquid trap communicates with a second chamber in communication with the second valve inlet port.   One or more refueling restriction valves (FLV) with a first valve inlet port connectable to one or more vent valves mounted on the fuel tank and a second valve inlet port mounted on the fuel tank The switching valve according to claim 1, wherein the switching valve can be connected.   The switching valve according to claim 1, wherein a wall that can be attached to the oil supply head is provided in the valve base portion, and an opening that directly communicates with the oil supply pipe is provided in the base wall.

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