Closure device for a fuel tank

Abstract

The invention relates to a closure device for a fuel tank in a motor vehicle. The closure device has a filling-level transmitter and a blocking element which both together form a constructional unit. The blocking element is adjustable so that is it movable to a position in which the blocking element closes an opening in the tank.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to a closure device having a blocking body for a fuel tank such as a fuel tank in a motor vehicle.

[0003] 2. Description of the Related Art

[0004] Fuel tanks for motor vehicles have a filler neck via which the fuel tank may be filled. As the tank is being filled, the fuel flowing into the tank displaces gas in the tank. To avoid uncontrolled flowing away of the displaced gas, tanks have ventilation systems via which the gas is conducted away in a defined manner both during the filling of the tank and during operation. Fuel should be prevented from entering the ventilation system to ensure reliable functioning of the ventilation system, particularly as the tank is being filled.

[0005] It is generally known to allow the filler pipe to open into the fuel tank below the upper boundary wall thereof and to arrange the ventilation system above this opening. A gas-filled space thereby remains above the liquid level in the tank and has the effect that a filling device feeding fuel into the tank via the filler pipe is switched off by the pressure building up in the filler pipe. This prevents the overfilling of the tank and therefore prevents the ventilation system from being filled with fuel when the tank is overfilled.

[0006] German reference DE 197 38 198 A1 discloses a device which prevents overfilling of the fuel tank in which control valves are arranged both in the ventilation system and in the filler pipe. Certain process parameters such as, for example, pressure and throughflow quantity are detected via a plurality of sensors which are arranged at different locations in the tank and the filler pipe. The signals generated by these sensors are passed to a control component which then acts upon the control valves in response to the corresponding control signals A problem with this known device is the complicated installation of this system because of the multiplicity of signal and control lines. In addition to the increased outlay required for laying the lines, additional sealing measures are also required with respect to the tank.

SUMMARY OF THE INVENTION

[0007] The object of the present invention is to provide a closure device for a fuel tank which allows a reliable switching off of the filling device and has a simple and robust construction and is easy to install.

[0008] According to the present invention, the object is achieved by a closure device for a fuel tank having an opening which is to be closed, the closure device comprising a constructional unit formed by a filling-level transmitter and a blocking element. The blocking element is adjustable so that it is movable into an orientation in which the blocking element closes the opening of the fuel tank

[0009] The closure device includes a filling-level transmitter and a blocking element which form a constructional unit. The blocking element is movable and closes the opening in one position. The constructional unit makes it possible for the closure device according to the invention to be constructed relatively compactly. The closure device requires few components and therefore takes up little space. The present invention obviates the need for lines which are complicated to lay and have to be sealed with respect to the tank.

[0010] Accordingly, both the filling-level transmitter and the blocking element may be held by a common carrier and arranged at the opening which is to be selectively closed. The carrier on which the filling-level transmitter and the blocking element are held may be designed with an appropriate configuration to adapt to the most varied openings and therefore to be used universally. Furthermore, the closure device may be assembled as a constructional unit outside the tank and functionally tested before installation, thereby simplifying the installation of the constructional unit in the tank.

[0011] The filling level transmitter of the present invention may include any of the known filling-level transmitters.

[0012] In a further embodiment, the blocking element is actuated via a mechanical link. The closure device may be made to be particularly simple and robust if lever-type transmitters or submerged transmitters are used as the filling-level transmitter. In this case, a float or lever arm is used as the actuating element for the blocking element. The mechanical link may include a gear mechanism, a cam mechanism or a lever mechanism arranged between the actuating element and the blocking element to facilitate the actuation of the blocking element. The blocking element may be a flap, a cone or a slide which is arranged pivotably or rotatably. The gear mechanism and the lever mechanism may be configured so that they only move the blocking element into its closing position after a certain filling level is reached. If the gear mechanism is a toothed-gear mechanism, a toothed-gear segment may be used instead of a complete toothed gear so that they only move the blocking element into its closing position after a certain filling level is reached.

[0013] In a further embodiment according to the present invention the level transmitter is a lever-type transmitter pivotally mounted in a bearing in a lever-type transmitter housing. In this case, the pivot area of the lever arm extends beyond the bearing in the lever-type transmitter housing so that the blocking element may be fastened to the lever arm. The closure device thereby requires particularly few components and can therefore be of very small construction.

[0014] In another embodiment of the present invention, the blocking element is actuated electrically by a signal produced by the filling-level transmitter being used to actuate the blocking element. This embodiment also obviates the separate installation of control and signal lines because of the direct arrangement of the blocking element on the filling-level transmitter. In this embodiment, any filling-level transmitters which indicate the filling level in the form of an electric signal may be used. The blocking element of this embodiment may be a 2-way directional control valve.

[0015] Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the drawings, wherein like reference characters denote similar elements throughout the several views:

[0017] FIG. 1 is a perspective view of a closure device for a fuel tank according to an embodiment of the present invention; and

[0018] FIG. 2 is a sectional schematic view of a tank having the closure device according to the present invention with the blocking element in an open position;

[0019] FIG. 3 is a sectional schematic view of a tank having the closure device according to the present invention with the blocking element in a closed position;

[0020] FIG. 4 is a schematic view of an embodiment of a mechanical link between the fill level transmitter and the blocking element;

[0021] FIG. 5 is another schematic view of an embodiment of a mechanical link between the fill level transmitter and the blocking element;

[0022] FIG. 6 is another schematic view of an embodiment of a mechanical link between the fill level transmitter and the blocking element;

[0023] FIG. 7 is a schematic view of another embodiment of a blocking element according to t he present invention ; and

[0024] FIG. 8 is a schematic view of yet another embodiment of a blocking element according to the present invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0025] FIG. 1 shows a carrier 2 placed onto the end of a filler pipe 1 of a fuel tank 11 (see FIGS. 2 and 3). The carrier 2 has a tubular section 3 and a housing 4. A rotatable flap 5 is arranged in the tubular section 3 for rotating about a spindle 13. When the rotatable flap 5 is oriented horizontally the tubular section 3 is open and when the rotatable flap 5 is oriented vertically the tubular section is closed by the rotatable flap 5. A filling-level transmitter 6 is arranged on the housing 4 and has a float 7 arranged on a lever arm 8. The lever arm 8 is mounted rotatably in the housing 4. An electric signal is obtained as a measure of the filling level by a sliding contact 9 which slides over a resistance mesh 10. A mechanical link 12 (see FIG. 2) is arranged in the housing 4 for connecting the lever arm 8 in its bearing to the rotatable flap 5.

[0026] FIG. 2 shows the fuel tank 11 with a low liquid level. Because of the low liquid level, the lever arm 8 points downward and the rotatable flap 5 is moved to a horizontal orientation via the gear mechanism in the housing 4. FIG. 3 shows the position of the lever 8 when the fuel tank 11 is filled up to the maximum height. When the fuel tank is filled up to its maximum height, the lever arm 8 is pivoted upward via the float 7. In this position of the lever arm 8, the rotatable flap 5, which is connected to the lever arm 8 via the gear mechanism, is moved into a vertical orientation so that the rotatable flap 5 closes the pipe 1.

[0027] FIGS. 4-6 show different embodiments of the mechanical link 12. In FIG. 4, the mechanical link comprises a gear mechanism including a first gear 16 connected to the lever arm 8 and a second gear 15 in meshed engagement with the first gear 16 and connected to the spindle of the rotatable flap 5. FIG. 5 shows an embodiment in which the mechanical link comprises a cam mechanism in which a cam 17 is arranged on the lever arm 8. As the lever arm 8 rotates, the cam 17 alters the position of the rotatable flap 5. FIG. 6 shows a lever mechanism including a lever 18 connected to the lever arm 8 for moving the rotatable flap 5.

[0028] Instead of a rotatable flap, a slide 20 may be used as a blocking element to close the opening to the fuel tank as shown FIG. 7. Instead of a mechanical link 12, the blocking element may be actuated via electrical signals generated by the level transmitter. For example, FIG. 8 shows a two-way directional control valve 22 which is actuatable via an electric signal from a fill-level transmitter 6a which is a submerged transmitter. In this embodiment, the blocking element is a cone which is part of the two-way directional control valve.

[0029] The invention is not limited by the embodiments described above which are presented as examples only but can be modified in various ways within the scope of protection defined by the appended patent claims.

[0030] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.

Claims

1. A closure device for a fuel tank having an opening which is to be closed, said closure device comprising:

a constructional unit including a filling-level transmitter arrangeable for determining of filling level of the fuel tank and a blocking element, wherein said blocking element is adjustable so that it is movable into a position in which the blocking element closes the opening of the fuel tank.

2. The closure device of

claim 1, wherein said filling-level transmitter comprises one of a lever-type transmitter having a lever arm and a submerged transmitter.

3. The closure device of

claim 1, wherein said blocking element comprises one of a flap, a cone and a slide.

4. The closure device of

claim 1, further comprising a mechanical link connected between said filling-level transmitter and said blocking element and comprising one of a toothed-gear mechanism, a cam mechanism and a lever mechanism, wherein said blocking element is mechanically actuatable in response to said filling-level transmitter via said mechanical link.

5. The closure device of

claim 1, further comprising a spindle, wherein said blocking element is fastened to said spindle for one of rotation or pivoting.

6. The closure device of

claim 5, wherein said filling-level transmitter comprises a lever arm and said spindle is directly connected to said lever arm.

7. The closure device of

claim 6, further comprising a float connected to said lever arm and wherein said float and said lever arm comprise components of a mechanism driving said blocking element.

8. The closure device of

claim 1, wherein said filling level transmitter generates an electrical signal in response to a fill level of the tank and said blocking element is actuated in response to said electrical signal.

9. The closure device of

claim 8, wherein the blocking element comprises a 2-way directional control valve.

10. The closure device of

claim 1, wherein said constructional unit comprises a carrier which holds the filling-level transmitter and said blocking element.

11. In a fuel tank of a motor vehicle having a filler pipe, a closure device comprising a constructional unit formed by a filling-level transmitter and a blocking element, wherein said blocking element is adjustable so that it is movable into a position in which the blocking element closes the opening of the fuel tank, wherein said closure device is arranged at an end of the filler pipe situated in one of the fuel tank and a ventilation system of the fuel tank.