Filling nozzle

The invention relates to a filling nozzle for dispensing a liquid into a tank of a motor vehicle, having a main valve (5). It is provided according to the invention that a safety valve (7) is arranged downstream of the main valve (5), which safety valve can be moved from a closed position into an open position by means of an opening movement directed in an upstream direction, and that a safety device (11) is provided which has an operative connection to the safety valve (7) and which is designed to detect the insertion of the filling nozzle into a tank provided for the corresponding liquid and which effects a movement of the safety valve from the closed position into the open position when an insertion of the filling nozzle into a tank provided for the corresponding liquid is detected.

This application is claims the benefit of European Application No. 12 192 496.3, filed Nov. 14, 2013, which is incorporated herein by reference in its entirety.

The invention relates to a filling nozzle for dispensing a liquid into a tank of a motor vehicle, having a main valve.

Filling nozzles for the refuelling of motor vehicles are known for example from EP 2 186 773 A1. Likewise known are filling nozzles with a misfilling inhibitor which is intended to ensure that dispensing of liquid takes place only after said filling nozzle has been inserted into a tank provided specifically for said liquid. In simple cases, such a misfilling inhibitor may merely comprise different diameters of the filling nozzle outlet pipe and of the filler neck of the associated tank, as is known for example in the case of filling nozzles for gasoline and diesel fuels.

As exhaust-gas standards become ever more stringent, some motor vehicles require auxiliary liquids which are intended to ensure low-emission combustion and thus reduce exhaust gas emissions. A known example here is in particular a 32.5% urea solution (known under the trade name AdBlue) which serves for reducing the nitrogen oxide emissions of diesel engines.

Urea solution is already widely used as an auxiliary liquid in the heavy goods vehicle sector, but in future will also be used in diesel passenger motor vehicles. The significance of a misfilling inhibitor will thus increase if passenger motor vehicles, too, are to have two tanks, one for diesel fuel and one for an auxiliary liquid such as urea solution.

It is therefore the object of the invention to provide a filling nozzle of the type mentioned in the introduction, which filling nozzle provides the possibility of improved safety against misfilling and can be implemented without problems in the filling station environment.

The invention achieves said object in that a safety valve is arranged downstream of the main valve, which safety valve can be moved from a closed position into an open position by means of an opening movement directed in an upstream direction, and in that a safety device is provided which has an operative connection to the safety valve and which is designed to detect the insertion of the filling nozzle into a tank provided for the corresponding liquid and which effects a movement of the safety valve from the closed position into the open position when an insertion of the filling nozzle into a tank provided for the corresponding liquid is detected.

Some expressions used within the context of the invention will firstly be explained.

A filling nozzle is a device for controlling the liquid flow during a tank filling process. The demands on the construction and mode of operation of automatic filling nozzles for use on filling pumps are governed by DIN EN 13012 Doc. 2001. Expressions defined in said standard are also used in the present application.

The feature “for dispensing a liquid into a tank of a motor vehicle” expresses the suitability of the filling nozzle for such a tank filling process.

The user controls the output of liquid by means of the main valve. An actuating lever (also referred to as switching lever) is generally used to actuate the main valve. The outlet pipe is the device through which the liquid is conducted into the vessel to be filled.

An additional safety valve is arranged downstream, that is to say in the intended flow direction of the liquid from the main valve to the outlet pipe. Said safety valve can be moved from a closed position, in which it blocks the liquid flow even when the main valve is open, into an open position by means of an opening movement directed upstream. This means that said safety valve must be opened counter to the flow direction of the outflowing liquid, and if appropriate counter to a pressure built up by said liquid. A further element of the filling nozzle according to the invention is a safety device which is designed to detect the insertion of the filling nozzle into a tank provided for the corresponding liquid.

The safety device is preferably designed to interact with a filler neck of a tank provided for the corresponding liquid. Said safety device is preferably moved from the blocking position into the enable position automatically by the insertion of the filling nozzle into the tank filler neck designed for the same. After the filling nozzle is inserted into the corresponding tank filler neck, the tank filling process can thus be commenced by actuating the actuating lever.

The safety device may for example be provided for interacting with the structural/mechanical configuration of a corresponding tank filler neck. Urea tanks in motor vehicles generally have a tank filler neck which tightly surrounds the outlet pipe of the associated filling nozzle already in the direct vicinity of the inlet region. The safety device may for example have an element which is arranged in a displaceable manner in the region of the outlet pipe and which is pushed from the blocking position into the enable position by the face-side edge of the tank filler neck, as will be described in more detail further below. Alternatively, the safety device may for example interact magnetically with a magnet arranged in the region of the tank filler neck.

The safety device is operatively connected to the safety valve. When the safety device detects an insertion into a suitable tank, an opening movement of the safety valve is effected by way of said operative connection. The safety valve thus moves, with an upstream direction component, from the closed position into the open position. Misfilling is prevented in this way.

The safety device may be designed as a detector, the safety valve may have a corresponding actuator, and the operative connection may for example be realized electrically.

Within the context of the invention, however, it is particularly preferable for the operative connection between the safety device and safety valve to be realized without external energy. External energy is any form of energy which is supplied specifically for the operation of the safety device or which is extracted from an energy source arranged in the filling nozzle. The expression external energy encompasses in particular electrical energy, and thus the filling nozzle according to the invention operates without electrical energy and therefore does not require an external electrical energy supply or an internal electrical energy source, for example a battery. The expression “operative connection between the safety device and safety valve” denotes, in functional terms, the actuation/manipulation of the safety valve by the safety device such that no opening of the safety valve takes place when the safety device is in the blocking position.

The design of the safety device according to the invention, and the operative connection thereof to the safety valve without external energy, in particular electrical energy, permits the use of the filling nozzle according to the invention in the direct vicinity of other filling nozzles which dispense fuel, and which must therefore satisfy particularly high demands with regard to explosion prevention. For example, the invention makes it possible for a filling nozzle for dispensing urea solution to be arranged in the direct vicinity of diesel or gasoline filling nozzles, for example on the same filling pump.

By contrast, filling nozzles known from the prior art which are used for urea solution and which have a corresponding safety device for preventing against misfilling require electrical energy for sensors which are intended to detect the insertion of the filling nozzle into a special so-called AdBlue tank and thus prevent misfilling. Said known filling nozzles must therefore be arranged remote from fuel filling pumps in order to satisfy the explosion prevention requirements. This makes a tank filling process for both diesel and also urea solution very much more cumbersome owing to the additional maneuvering process that is required. For heavy goods vehicles used in the commercial sector, this may be acceptable, but in the passenger motor vehicle sector, such a dual tank filling process, with the vehicle having to be moved in between, would be unacceptable. The invention makes it possible for filling nozzles for urea solution to be combined with those for diesel fuel in close proximity, for example on a single filling pump.

According to the invention, the operative connection between the safety device and safety valve is preferably realized magnetically. For example, the safety device may have an element which can be displaced by the insertion of the outlet pipe of the filling valve into a tank provided for the same, and which has a magnet, the displacement of which effects an opening movement of said safety valve owing to interaction with a magnet arranged on the safety valve, for example on the valve shank thereof. Alternatively, a corresponding magnet may be arranged in the region of the tank filler neck, which magnet interacts with the magnet of the valve shank. The insertion of the filling nozzle into the tank takes place with the main valve closed, and thus the region of the filling nozzle downstream of the main valve is unpressurized, such that, before the opening of the main valve, the opening movement of the safety valve can be effected by means of even relatively low magnet forces because said opening movement does not need to take place counter to the back pressure of liquid present upstream of the safety valve.

The safety valve is preferably arranged in the region of the outlet pipe, and the valve seat may be arranged in the region of the outlet end of the outlet pipe. The valve and valve shank are preferably designed such that the safety valve is preloaded into the closed position by liquid pressure in the outlet pipe. In this way, the sealing action of the safety valve is intensified if, owing to incorrect operation, the main valve is opened before the safety valve has detected an insertion into a suitable tank filler neck and thereby opened the safety valve. Misfilling is thus reliably prevented even in the case of incorrect operation.

In a preferred embodiment of the invention, a sliding sleeve which is displaceable axially relative to the outlet pipe may be arranged in the region of the outlet, which sliding sleeve has arranged thereon or connected thereto an operative magnet that interacts with the magnetically actuable safety valve. Here, the expression “operative magnet” refers merely to the fact that the magnet is designed for corresponding interaction with, and thus operative connection to, the safety valve. According to the invention, an operative magnet of said type may also be arranged on or in the region of the safety valve. It is possible for one or more magnets to be provided either exclusively on the safety valve or exclusively in the region of said sliding sleeve, which magnet or magnets interact(s) with a magnetizable material of the corresponding counterpart element (sliding sleeve or safety valve), such as for example iron or iron alloys. It is however preferable if corresponding magnets are arranged both on the sliding sleeve and also the safety valve. Where reference is made, within the context of the invention, to magnets or a magnetic interaction, permanent magnets are preferable.

It may be possible for the sliding sleeve to be automatically displaced from a blocking position into an enable position by the insertion of the filling nozzle into a tank filler neck designed for the same. Said displacement of the sliding sleeve then effects a magnetic opening of the safety valve, such that, after the insertion into the correspondingly designed tank filler neck, the main valve of the filling nozzle can be opened by means of the actuating lever, and the tank filling process can be commenced.

The filling valve according to the invention may additionally have a gas extraction device, such as is basically known from the prior art. Since ammonia can be formed as a result of the breakdown of urea, such a gas extraction device can contribute to the prevention or reduction of an unpleasant smell during the filling of a tank with urea.

Automatic filling nozzles generally have a safety shut-off means which automatically stops the tank filling process when the tank is full. For this purpose, the outlet pipe has a so-called sensor line which communicates pneumatically with a triggering device, arranged in the region of the main valve, for said main valve. The details of the design of a safety shut-off means of said type are well known to a person skilled in the art and are disclosed for example in EP 2 386 520 A1. If, during the course of a tank filling process, the liquid level reaches the end of the outlet pipe and thus the inlet of the sensor line, the pressure conditions in the sensor line change and lead to a triggering, and thus a closure, of the main valve. According to the invention, it is advantageous if a safety shut-off means of said type is additionally designed to close the main valve if the back pressure between the main valve and safety valve rises above a predetermined threshold value. If the main valve is opened by means of the actuating lever when the safety valve is still closed, the pressure in the outlet pipe upstream of the safety valve rises up to the operating pressure that prevails upstream of the main valve, said operating pressure being produced by the pump of the filling pump. The result is an increased pressure difference between the pressure in the outlet pipe, on the one hand, and in the sensor line of the safety shut-off means, on the other hand (details with regard to these expressions can be found in EP 2 386 520 A1), and said increased pressure difference leads to a triggering of the safety shut-off means and thus a decoupling of the main valve from the actuating lever; the main valve can then be moved into the closed position again by the closing spring. Said additional safety measure prevents a situation in which, in the event of incorrect operation (the actuating lever being pulled when the filling nozzle is not correctly inserted), the entire operating pressure prevailing at the filling nozzle must initially be held back by the safety valve alone, and dissipated via the sensor line with a time delay.

The 32.5% aqueous urea solution, used as AdBlue, is a highly concentrated salt solution. If drips fall from a filling nozzle for urea solution during the handling thereof, conspicuous salt marks form after the solvent, water, evaporates. The safety valve according to the invention can additionally perform the function of a drip prevention valve in the region of the outlet end. It prevents residual amounts of liquid still present in the outlet pipe from dripping out when the safety valve is closed.

The invention thus also relates to a filling nozzle according to the invention which is designed for dispensing urea solution.

The invention also relates to a filling pump for the combined dispensing of fuels and urea solution, which filling pump has at least one filling nozzle for dispensing fuel (in particular diesel fuel). According to the invention, said filling pump also has at least one filling nozzle according to the invention for dispensing urea solution. Such a filling pump permits a convenient simultaneous or directly successive tank filling process with fuel, in particular diesel fuel, and urea solution. Maneuvering of the vehicle in between is not necessary. The configuration of the filling nozzle according to the invention for dispensing urea solution without the supply of external energy, in particular electrical energy, allows it to be used in the direct vicinity of a filling pump for dispensing fuels.

A filling nozzle (also referred to colloquially as “pistol-grip nozzle”) according to the invention has a valve housing1, an inlet2, connected to a hose (not illustrated), for liquid, an outlet pipe3and a switching lever4. In a known manner described for example in EP 2 386 520 A1, the switching lever4actuates the main valve5of the filling nozzle. A sensor line6communicates pneumatically with the surroundings of the outlet end of the outlet pipe3, and can thus, in a conventional manner as described in the cited EP document, effect a complete shut-off of the tank.

In the region of the outlet end of the outlet pipe3there is provided a safety valve7which, downstream, closes against a valve seat8. The upstream end of the valve shank9is provided with a magnet10.

A sliding sleeve11is arranged around the outer circumference of the outlet pipe3in the region of the outlet end. The sliding sleeve11is preloaded by a compression spring12into the blocking position illustrated inFIG. 1, in which said sliding sleeve is situated in an axial end position in the direction of the outlet end of the outlet pipe3. An annular operative magnet13is arranged on the sliding sleeve11. The sliding sleeve11is received in a displaceable manner in a cylindrical pocket14which concentrically surrounds the outer circumference of said sliding sleeve, which pocket also receives the compression spring12.

In the position shown inFIG. 1, the safety valve is preloaded into the closed position by the magnetic interaction between the operative magnet13and magnet10.

In the operating state illustrated inFIG. 1with the safety valve7closed, if the actuating lever4is pulled, the main valve5firstly opens and allows liquid to flow into the outlet pipe3. The pressure therein rises because the safety valve7does not allow said liquid to flow out of the outlet pipe3. If the pressure rises above a defined threshold value, a differential pressure is generated across the means, indicated at15, for completely shutting off the tank, or across the diaphragm of said means, such that said differential pressure triggers the means for completely shutting off the tank and decouples the actuating lever4from the main valve5in a known way, such that the main valve5is closed again by its closing spring. The threshold value for the pressure at which such triggering takes place lies above the pressure that prevails in the outlet pipe3during a conventional tank filling process, and below the operating pressure (provided by the pump of the filling pump) at the inlet2of the filling nozzle.

FIG. 2shows a state in which the filling nozzle according to the invention is partially inserted into the tank filler neck of an associated urea tank. The safety valve7is, as before, closed.

InFIG. 3, the outlet end of the outlet pipe3is fully inserted into the tank neck16of a urea tank of a passenger motor vehicle. Said tank neck is designed so as to tightly surround the outlet pipe already in the direct vicinity of the start of the filler neck, as illustrated inFIG. 3. The annular face surface of the sliding sleeve11abuts against the corresponding counterpart surface of the tank filler neck16, and the sliding sleeve11is displaced from the blocking position illustrated inFIGS. 1 and 2into the enable position illustrated inFIG. 3, counter to the pressure of the spring12. In said enable position, the upstream end of the sliding sleeve11abuts against a stop. The operative magnet13is correspondingly also displaced axially together with the sliding sleeve11. Owing to the magnetic operative connection between the operative magnet13and the magnet10on the valve shank9, the safety valve7is moved into the open position illustrated inFIG. 3. Said opening movement takes place in the upstream direction. The tank filling process can be commenced by virtue of the switching lever4being pulled and the main valve5thereby being opened. The outflow of liquid through the outlet pipe3is such that the safety valve7remains in its open position and the tank filling process can be performed.

The tank filling process can be ended in the conventional way by releasing or unlocking the actuating lever4. If the tank has been substantially filled, the end of the outlet pipe3, and thus also the sensor line6, are immersed in liquid. The pressure difference that is thus effected pneumatically effects a shut-off of the main valve, and thus a termination of the tank filling process, in a conventional manner described for example in EP 2 386 520 A1.

The tank filling process is likewise ended if the filling nozzle is pulled out of the tank filler neck16and the sliding sleeve11is pushed from the enable position inFIG. 3back into the blocking position ofFIG. 1or2by means of the spring12. Owing to the magnetic interaction between the annular magnet13(operative magnet13) and the magnet10, the safety valve7is moved, in the downstream direction, back into its closed position. If the main valve5is now still open, the pressure rise in the outlet pipe3results in an above-described triggering of the means15for completely shutting off the tank, and thus a closure of the main valve5.

Gases escaping during the course of the tank filling process can, in a conventional manner, be recirculated by the filling nozzle through a gas extraction duct (not illustrated).

FIG. 4shows the situation when a filling nozzle according to the invention is inadvertently inserted into a tank filler neck for unleaded gasoline or diesel fuel. The sliding sleeve11remains, in any case, in the blocking position, such that no tank filling process can take place. If the actuating lever4is nevertheless pulled, the pressure rise in the outlet pipe3with the safety valve7closed leads to a triggering of the means15for completely shutting off the tank, and thus again to a closure of the main valve.

FIGS. 5 and 6show a further embodiment of the invention. The sliding sleeve11is omitted in this embodiment. The preloading of the safety valve7into the closed position is realized here by means of a closing spring12′ assigned directly to the safety valve7.

Here, the opening of the safety valve7counter to the force of the spring12′ takes place, during the insertion process into a tank filler neck, by interaction of the magnet10with an annular magnet arranged in the tank filler neck.

FIG. 5shows this embodiment of the invention inserted into a passenger motor vehicle filler neck for urea solution, said filler neck having an annular magnet13′. After the filling nozzle has been fully inserted into the neck, magnetic interaction occurs between the magnet10and the magnet13′, such that the safety valve7opens and the tank filling process can be commenced.

FIG. 6shows this embodiment of the invention inserted into a filler neck for urea solution in a heavy goods vehicle, said filler neck being of slightly different construction. Here, too, after the filling nozzle has been fully inserted, the safety valve7is opened by interaction of the magnet10with an annular magnet13″ arranged in the filler neck.

FIG. 7shows the embodiment ofFIGS. 1-4inserted into a filler neck which has an annular magnet13′. It can be seen that, in this case, the opening of the safety valve7is realized in the conventional manner by interaction between the magnet10and the magnet13. The magnet13′ arranged in the filler neck does not have a detrimental effect because it is arranged spatially too far away from the magnet10.