Nozzle with discrete switching gas valve and apparatus comprising nozzle and gas return system

Abstract

The invention relates to a nozzle for dispensing fluid into a tank, the nozzle comprising means for returning fluid vapor; a gas valve comprising a gas valve body and a gas valve seat and being configured to switch discretely between a closed position and an open position; the gas valve body being connected to an actuating magnet displaceable in a non-ferromagnetic actuator housing to open and close the gas valve; the nozzle comprising an operating magnet mounted outside the actuator housing to be displaced between a starting position and an end position established by a stop and being magnetically coupled to the actuating magnet. A floating element is displaceably mounted outside the actuator housing so as to be loadable by the fluid to be dispensed and thereby movable against the force of a return element, wherein the floating element has at least one floating magnet which is couplable to the operating magnet. The floating element provided with a return element allows the operating magnet to be safely pressed into the closed position, so that the nozzle is less susceptible to dust and can be flexibly used in a multi-dispenser return gas system.

Description

TECHNICAL FIELD

[0001] The invention relates to a nozzle for dispensing fluid into a tank. The nozzle comprises means for returning fluid vapors, which means comprise a gas valve, which can be connected to a vacuum source via a gas hose. The gas valve comprises a gas valve body and a gas valve seat and is configured to be switched discretely between a closed position, in which the gas valve body lies tightly on the gas valve seat, and an open position, in which a maximum opening cross section is opened. The gas valve body is connected to an actuating magnet, which is mounted displaceable in a non-ferromagnetic actuator housing in order to open and close the gas valve. The nozzle further comprises an operating magnet, which is mounted outside the actuator housing displaceable between a starting position and an end position established by a stopper and is magnetically coupled to the actuating magnet. BACKGROUND

[0002] When fluid is transferred from a storage container into a tank, fluid vapors present in the tank are discharged from the tank. In particular in the case of fluid vapors which are harmful to health and the environment, such as fuel vapors, it is necessary to prevent them from escaping into the environment. Therefore, in the prior art, fluid vapors are typically sucked in at the nozzle outlet and guided back to the storage container. For this purpose, a gas suction connector is provided in the region of the nozzle outlet pipe and is connected via a gas valve to a gas hose and to a vacuum source.

[0003] The gas volume of the amount of gas discharged from the tank, which gas volume is disregarding the volume change due to temperature differences, corresponds to the fluid volume of the fluid transferred from the storage container into the tank. Therefore, it is known from the prior art to control the amount of fluid vapors returned such that the gas volume corresponds to the fluid volume dispensed. In this way, it can first be ensured that no fluid vapors escape into the environment. Secondly, in addition to the displaced gas volume, it can be prevented that ambient air is sucked in and guided into the tank.

[0004] In order to control the gas return, the fluid volume dispensed can be measured and the power of the vacuum source is adjusted accordingly, such that the gas volume returned corresponds to the fluid volume dispensed. During fuel dispensing, it is here necessary to open the gas valve located in the nozzle to allow the gas return. The document EP 0 703 186 A2 discloses a nozzle of the type mentioned at the outset, wherein, during dispensing, the operating magnet is loaded by the flowing fluid and is thereby moved downstream, whereby the actuating magnet coupled to the operating magnet and the gas valve body connected thereto are moved into the open position.

[0005] In the previously known nozzle, by its appropriate orientation, the operating magnet can also be moved with the help of gravity after actuation by the flowing fluid. In particular, the previously known nozzle is tilted downwards upon insertion into the tank connection nozzle, whereby the gas valve is opened. Upon subsequent return of the nozzle onto the pump nozzle holder, the nozzle is tilted upwards, so that the operating magnet moves back into the starting position under the action of gravity and the gas valve is correspondingly closed.

[0006] The operation of the gas valve by means of gravity also allows for so-called dry testing, in which the function of the gas valve can be tested without fluid dispensing.

[0007] The requirement that the gas valve of the previously known nozzle can be operated by means of the fuel flow and by means of gravity places high demands on component tolerances. In particular, it must be ensured that contaminants, which can be contained in the fluid to be dispensed, for example, do not deposit between the operating magnet and the actuator housing and thus do not impair the function. SUMMARY

[0008] It is an object of the present invention to provide a nozzle of the type mentioned at the outset, which can be switched discretely between a closed position and an open position and which can be used with high reliability and safety in a structurally simple manner.

[0009] This object is achieved by the nozzle described hereinafter and by the device comprising a gas return system and at least one nozzle.

[0010] According to the invention, a floating element is displaceably mounted outside the actuator housing and can be loaded by the fluid to be dispensed, so as to move against the force of a return element, wherein the floating element has at least one floating magnet, which can be coupled to the operating magnet.

[0011] First, some terms used in connection with the present description will be explained.

[0012] In the context of the present description, the phrase "discrete switching of the gas valve between a closed position and an open position" means that from the closed position, even with a small valve stroke, the maximum opening cross section of the gas valve can be achieved. Thus, from the closed position, the opening cross section rises sharply, in particular disproportionately or by means of a jump, to the maximum opening cross section, wherein a further valve stroke does not cause a change in the opening cross section or only a small change in the opening cross section. The valve stroke for reaching the maximum opening cross section can be, for example, less than 8 mm and preferably less than 7 mm. Thus, the discretely switchable gas valve is quite different from a so-called proportional valve, in which the opening cross section rises in proportion to the valve stroke over a longer valve stroke, for example, more than 10 mm.

[0013] The floating magnet can be coupled to the operating magnet. In the coupled state, the movement of the floating element is transmitted to the operating magnet via this magnetic coupling and thus via a further magnetic coupling to the gas valve body. Thus, the gas valve body can be moved together with the floating element in the coupled state. The coupled state must be distinguished from the decoupled state, in which there is sufficient distance between the floating magnet and the operating magnet so that the magnetic attraction is not sufficient to transmit the movement of one element to the other element.

[0014] In the context of the present invention, it has been found that the previously known nozzle from EP 0 703 186 A2 is improved in two respects at the same time due to the movably mounted float, whose float magnet can be coupled to the operating magnet.

[0015] Firstly, when a coupling is generated between the floating magnet and the operating magnet, the force of the return element acting on the floating element is transmitted to the gas valve body via the actuating magnet to press it into the closed position. It has been found that due to this design, the gas valve is significantly less susceptible to contamination, since the return force can overcome the frictional forces caused by contamination.

[0016] Furthermore, in the context of the present invention, it has been found that the nozzle according to the invention is significantly better suited for use in a return gas system designed for multiple dispensing points (hereinafter referred to as a multi-dispenser return gas system) than the previously known nozzle. In the simplest design, such a multi-dispenser return gas system has one control element and a single vacuum source configured for multiple dispensing points, which control element ensures that the total volume of gas drawn in is as large as the total volume of fluid dispensed by the connected nozzles. In such a return gas system, when the dispensing process of a (previously known) first nozzle ends and no fluid is dispensed any more, but the nozzle remains inclined downwards at the spout for a longer period of time, the gas valve of the first nozzle also remains open (because the outlet tube is inclined downwards). If fluid is now dispensed simultaneously from a second nozzle connected to the return gas system, the return gas system will remain active so that there is a risk that gas will continue to be drawn in through the still open gas valve of the first nozzle, even if no fluid is dispensed. Since no fluid is dispensed through the first nozzle, in this case ambient air can be drawn in and introduced into the storage container, which is undesirable. Therefore, for the previously known nozzle, it is necessary to provide a separate vacuum source or a separate control element for the return gas of each individual dispensing point, which makes the return gas system significantly more complex and less economical.

[0017] In contrast, for the nozzle according to the invention, when no fluid is dispensed, the return element ensures that the gas valve body is automatically moved into the closed position. In contrast to the nozzle previously known from EP 0 703 186 A2, in which the gas valve remains in the open position while the outlet tube is inclined downwards, the gas valve of the nozzle according to the invention is automatically closed immediately after the fluid dispensing is completed.

[0018] The nozzle according to the application is therefore particularly suitable for use in a multiple-dispenser return-air system of the type mentioned above, which has one control element and a single vacuum source for a plurality of dispensing points, the control element ensuring that the total volume of the suction gas is as large as the total volume of the fluid dispensed by the connected nozzles. When using the nozzle according to the application in a multiple-dispenser return-air system, it is therefore not necessary to provide each nozzle with a separate vacuum source or a separate control element.

[0019] The restoring force of the restoring element is preferably chosen such that, in the absence of fluid flow, when a magnetic coupling is generated between the operating magnet and the floating magnet and the nozzle is tilted downwards, the restoring element presses the air valve into the closed position. "Tilted downwards" here means the position assumed by the nozzle during a normal dispensing process, in which the angle of inclination between the outlet tube and the horizontal is for example between 0° and 90°, preferably between 5° and 70°, more preferably between 10° and 60°. The restoring force can in particular be chosen to be greater than the total weight of the air valve body and the elements connected thereto and magnetically coupled thereto, when a magnetic coupling is generated between the operating magnet and the floating magnet. This results in the air valve closing in the absence of fluid flow, even if the nozzle is tilted downwards. Once the fluid dispensing has ended, the air valve body of the nozzle according to the application moves into the closed position, so that no fluid vapour is drawn in any more and the reduced pressure of the vacuum source of the connected multiple-dispenser return-air system is fully available for the nozzle to be used further.

[0020] It can be provided that the restoring force of the restoring element is adjustable. For example, the restoring element can be formed by a restoring spring, wherein the restoring force is preferably adjustable by means of a stepless or stepwise actuating element.

[0021] It can be provided that only one of the operating magnet and the actuating magnet is configured as a permanent magnet, while the other part is made of a ferromagnetic material. Correspondingly, it can be provided that only one of the operating magnet and the floating magnet is configured as a permanent magnet, while the other part is made of a ferromagnetic material.

[0022] It is provided in a preferred embodiment that, in the closed position of the air valve and with the floating element in the starting position, the magnetic coupling between the operating magnet and the floating magnet is so strong that the air valve body is held in the coupled state in the absence of dispensing fluid and with the nozzle tilted downwards. The magnetic coupling can in particular be configured such that, in the case described above, it is stronger than the weight of the operating magnet and the elements connected thereto, for example via the magnetic coupling.

[0023] Further preferably, in the closed position of the gas valve and with the floating element in the starting position, the magnetic coupling between the operating magnet and the floating magnet can be so strong that, despite the absence of fluid dispensing, the magnetic coupling can be separated by a sudden movement applied by the user against the opening direction of the actuating magnet, so that a dry test of the device for extracting the fluid vapour can be performed. The separability of the coupling means that the operating magnet can be separated from the floating magnet, so that the operating magnet can move the gas valve into the open position even without dispensing fluid. This allows a dry test of the device for returning the fluid vapour and of the gas return system connected thereto.

[0024] In one embodiment, the nozzle comprises means for selectively mechanically fixing the floating element to the operating magnet. Thanks to the mechanical fixing of the floating element to the operating magnet, the operating magnet (and therefore also the gas valve body) must follow the movement of the floating element. Therefore, after the fixing has been created, it is no longer possible to perform a dry test which requires the separation of the floating element and the operating magnet. The selective fixability described above allows the possibility of dry test to be disabled very easily. This is advantageous because in many jurisdictions it is prohibited to offer the possibility of dry test.

[0025] Furthermore, the present application relates to a device comprising a gas return system and at least one nozzle according to the present application, the gas return system being configured to return fluid vapour from a plurality of nozzles, wherein the gas return system comprises a vacuum source connected to the gas valve, a measuring unit for determining the total fluid volume flow dispensed by the nozzle, and a control device for controlling the vacuum source depending on the total fluid volume flow. BRIEF DESCRIPTION OF DRAWINGS

[0026] The preferred embodiments of the present application are explained hereinafter, by way of example, with reference to the accompanying drawings. In the drawings:

[0027] Figure 1 a partial cutaway side view of a nozzle according to the present application is shown;

[0028] Figure 2 a section of Figure 1 is shown in an enlarged view, wherein the nozzle is shown in a first state;

[0029] Figure 3 a view of Figure 2 is shown, wherein the nozzle is in a second state;

[0030] Figure 4 a view of Figure 2 is shown, wherein the nozzle is in a third state;

[0031] Figure 5 a section of a side cross-sectional view of a further embodiment of a nozzle according to the present application is shown;

[0032] Figure 6 A schematic diagram of the device according to the present invention is shown. Detailed Implementation

[0033] Figure 1 A nozzle according to the invention is shown in a partially cut-away side view. The nozzle has a housing 21, into which an outlet pipe 22 is inserted; the outlet pipe can be introduced into the housing of a motor vehicle to fill the housing with fuel. At the rear end of the nozzle is a connector 23 for connection to a nozzle hose (not shown).

[0034] The nozzle has a control lever 24, which is constructed in a manner known in principle and not described herein, for operating the main valve. After the main valve is opened, fuel supplied via a connected nozzle hose can travel through the nozzle housing 21 and the outlet pipe 22, thereby filling the vehicle's cargo box.

[0035] To prevent fuel vapors from escaping from the housing into the environment, the nozzle has a collecting connector 26 surrounding the outlet pipe 22. Between the outlet pipe 22 and the collecting connector 26 is an intermediate space through which fuel vapors can be drawn in. This intermediate space extends within the housing 21 to a gas valve 20. The gas valve 20 is then connected to a gas hose (not shown). The gas hose extends coaxially within the nozzle hose and is connected to a vacuum source (not shown).

[0036] Figure 2 Shown in magnified view Figure 1 The section. In this view, it is clear that valve 20 has a central valve seat 15 and a valve body 17. When valve 20 is open, fuel vapor flows along... Figure 2 Arrow 24, as marked in the middle, flows through gas valve 20 and into the gas hose. However, in Figure 2 In the indicated state, the valve body 17 is pressed tightly against the valve seat 15, thus closing the connection between the gas storage connector 26 and the gas hose. Besides the gas flow path, Figure 2 The fuel flow path, guided through the fuel channel and indicated by arrow 33, is also shown.

[0037] The valve body 17 is connected to an actuating magnet 16, which is repositionably mounted within the actuator housing 14. Furthermore, an operating magnet 9, magnetically coupled to the actuating magnet 16, is disposed outside the actuator housing 14. In the illustrated embodiment, an additional weight 10 is attached to the operating magnet 9.

[0038] Due to the magnetic coupling, a movement of the operating magnet 9 downstream (relative to the fuel flow) causes the actuating magnet 16 (and thus the valve body 17) to be entrained and thus moved into the open position. Even over a valve stroke of approximately 5 mm, the entire open degree cross section of the gas valve 20 for the gas flow is opened. Further movement of the valve body 17 in the opening direction does not increase the open degree cross section.

[0039] Furthermore, the float element 7 is arranged inside the fuel channel and is loaded with fuel when the main valve is opened. This is shown in Figure 3 .

[0040] Figure 3 A section of Figure 2 is shown in a state after the main valve has been opened. The fuel flowing through the nozzle along arrow 33 hits the float element 7 and thus moves downstream (to the left in Figure 2 ) against the force of the spring 12. During this movement, the float element 7 is at least partially on the operating magnet 9 (or at least partially on the cover around the operating magnet 9), so that the operating magnet moves downstream together with the float element 7. Due to the above-mentioned magnetic coupling between the operating magnet 9 and the actuating magnet 16, the valve body 17 also moves downstream into the open position, so that fuel vapors can be extracted.

[0041] At the end of the fuel dispensing, the force directed downward on the float element 7 by the fuel pressure disappears. The return force of the spring 12 then pushes the float element 7 back into the starting position shown in Figure 1 . On the upstream side of the float element 7, the float magnet 8 is arranged, which is magnetically coupled to the operating magnet 9 in the state shown in Figure 1 and Figure 2 . Due to the magnetic coupling, the operating magnet 9 is carried by the float magnet 8, so that the operating magnet 9 also moves back into the starting position shown in Figure 2 . Due to the magnetic coupling between the operating magnet 9 and the actuating magnet 16, which has already been described, the valve body 17 is brought back into the closed position shown in Figure 2 . This ensures that the gas valve is closed after the end of the fluid dispensing. Here, the return force of the spring 12 is greater than the total weight force that arises from the nozzle inclination during the refueling process, which is exerted by the elements moved by the spring 12 (float element 7, float magnet 8, operating magnet 9, additional weight 10, actuating magnet 16, valve body 17, any other elements, such as covers).

[0042] Figure 4 A section of Figure 1 is shown, in which the nozzle is in a dry test state. In this state, no fuel flows through the nozzle, so the float 7 is pressed into the starting position shown in Figure 2 by the force of the spring 12. Starting from the state in Figure 2 , in order to generate Figure 4In this state, the user suddenly moves the nozzle relative to the opening direction of the air valve 20. Due to the inertia of the operating magnet 9 and the attached additional weight 10, this sudden movement causes the magnetic coupling between the operating magnet 9 and the floating magnet 8 to disengage. Therefore, the operating magnet 9 can move accordingly away from the floating magnet 8, and thus move the air valve body 17 to the open position. In this state, the function of the device for returning fuel vapor and the entire return air system can be tested without fuel dispensing.

[0043] Figure 5 A further embodiment of the nozzle according to the invention is shown in a side sectional view. This embodiment substantially corresponds to... Figures 1 to 4 Examples of implementations. With Figures 1 to 4 The only difference in the embodiment is that a fixing element is attached to the outer periphery of the additional weight 10, which in this embodiment is constructed as, for example, a helical tension spring 18. The helical tension spring 18 is placed in a corresponding groove on the outer periphery of the additional weight 10 and extends radially beyond the outer periphery of the additional weight 10.

[0044] When a downward force is applied to the operating magnet 9 or the attached weight 10 (e.g., triggered by the aforementioned sudden movement), the helical tension spring 18 strikes the inward-pointing protrusion 19 of the floating element 7, preventing the operating magnet 9 from moving downstream independently of the floating element 7. Therefore, the operating magnet 9 can only move together with the floating element 7. However, since the floating element 7 is pressed upstream into the starting position by the spring 12, the operating magnet 9 also remains in the starting position. Therefore, for this embodiment, a dry test requiring independent mobility of the operating magnet 9 and the floating element 7 is not possible. When there is no fuel flow, the valve body 17 in this embodiment always moves to the closed position.

[0045] Figure 6 A schematic diagram of an apparatus according to the invention is shown, comprising four nozzles 40 according to the invention and a return gas system 35. The return gas system 35 includes a vacuum source 36, to which the nozzles 40 according to the invention are connected by means of suitable gas hoses 41.

[0046] The return gas system 35 also includes a measuring unit 37 for determining the total volumetric flow rate distributed by the nozzle 40. In the current configuration, the measuring unit 37 establishes the distributed total volumetric flow rate directly at the fuel pump 39 supplying fuel to the nozzle 40, such as... Figure 6The connection of the measuring unit 37 to the fuel pump 39 is shown in the middle. In an alternative embodiment, a plurality of fuel pumps can also be provided, which transfer a corresponding partial volume flow to the measuring unit 37 in order to allow the measuring unit to determine the total volume flow. Furthermore, the gas return system 35 comprises a control device 38, which is configured to receive a measurement value representing the determined total volume flow and to control the vacuum source 36 in dependence on the measurement value.

[0047] For example, if a fuel volume flow of 20 l / min is dispensed at the first nozzle 40, a fuel volume flow of 20 l / min is dispensed at the second nozzle, and the other two nozzles 40 are not used, the measuring unit 37 establishes a total volume flow of 40 l / min. The vacuum source 36 is set accordingly by the control device 38, so that a gas volume of 40 l / min is drawn off. Since only the first and second nozzles 40 are used, the gas valves of the first and second nozzles are opened, while the gas valves of the third and fourth nozzles remain closed. The vacuum generated is thus "divided" onto the two nozzles 40 in use, so that the necessary fuel vapor volume is drawn off and returned at the two nozzles 40. The gas volume returned is guided by the vacuum source 36 into the tank 42.

Claims

1. A nozzle for dispensing fluid into a tank, wherein: the nozzle comprises means for returning fluid vapour, which means comprise a gas valve (20) connectable to a vacuum source via a gas hose; the gas valve (20) comprises a gas valve body (17) and a gas valve seat (15) and is configured to switch discretely between a closed position, in which the gas valve body (17) lies tightly on the gas valve seat (15), and an open position, in which a maximum opening cross section is open; the gas valve body (17) is connected to an actuating magnet (16) mounted displaceable in a non-ferromagnetic actuator housing (14) in order to open and close the gas valve (20); the nozzle comprises an operating magnet (9) mounted outside the actuator housing (14) displaceable between a starting position and an end position established by a stop (5) and magnetically coupled to the actuating magnet (16); characterised in that a floating element (7) is mounted displaceably outside the actuator housing (14) loadable by the fluid to be dispensed so as to be movable against the force of a return element (12), wherein the floating element (7) has at least one floating magnet (8) couplable to the operating magnet (9).

2. The nozzle of claim 1, wherein, the return force of the return element (12) is selected such that, in the absence of fluid flow, when a magnetic coupling is produced between the operating magnet (8) and the floating magnet (8) and the nozzle is tilted downwards, the return element (12) presses the gas valve (20) into the closed position.

3. The nozzle of claim 1 or 2, wherein, only one of the operating magnet (9) and the actuating magnet (16) is configured as a permanent magnet and the other is made of a ferromagnetic material.

4. The nozzle of any one of claims 1 to 3, wherein, only one of the operating magnet (9) and the floating magnet (8) is configured as a permanent magnet and the other is made of a ferromagnetic material.

5. The nozzle of any one of claims 1 to 4, wherein, in the closed position of the gas valve (20) and with the floating element (7) in the starting position, the magnetic coupling between the operating magnet (9) and the floating magnet (8) is strong enough for the operating magnet (9) to be held in the coupled state in the absence of dispensing fluid and the nozzle being tilted downwards.

6. The nozzle of any one of claims 1 to 5, wherein, in the closed position of the gas valve (20) and with the floating element (7) in the starting position, the magnetic coupling between the operating magnet (9) and the floating magnet (8) is strong enough for the magnetic coupling to be able to be broken by a sudden movement applied by the user relative to the opening direction of the actuating magnet, despite the absence of fluid dispensing, so that the means for extracting fluid vapour can be tested dry.

7. The nozzle according to any one of claims 1 to 6, comprising means for selectively mechanically fixing the floating element to the operating magnet.

8. An apparatus comprising a return gas system (35) configured to return fluid vapor from a plurality of the nozzles (40) and at least one nozzle (40) according to any one of claims 1 to 7, wherein, The return air system (35) comprises a vacuum source (36) connected to the air valve (20), a measuring unit (37) for determining the total volumetric flow dispensed by the nozzle (40), and a control device (38) for controlling the vacuum source (36) as a function of the total volumetric flow.

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