CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application Nos. 62/247,960, filed October 29, 2015 and 62/408,858 filed on October 17, 2016, the contents of which are incorporated herein by reference thereto.

FIELD

[0002] The present disclosure relates generally to vehicle fuel tank systems and, more particularly, to fuel measurement within a semi-rigid vehicle fuel tank and low fuel measurement within a vehicle fuel tank.

BACKGROUND

[0003] Motor vehicles may rely on fuel gauges to provide information on the amount of fuel remaining in the tank. Typically, a mechanical float and lever are disposed inside the tank. When the fuel level changes in the tank, the float causes the lever to pivot, which generates an electrical signal.

[0004] However, the accuracy of float systems may be limited because the fuel tank changes shape or the float assembly is damaged. In addition, basic calibration error of the assembly, tip angles of the vehicle, and liquid sloshing may also cause inaccurate low fuel indication. Further, flexible fuel tanks may sag as the fuel tank ages, which may alter sensor reference points and cause fuel level measurements to become inaccurate. Accordingly, while current systems work well for their intended purpose, it is desirable to provide an improved system to measure the amount of fuel in a fuel tank.

[0005] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. SUMMARY

[0006] In one aspect, a fuel level measurement system for a fuel tank assembly having a semi-rigid fuel tank having an upper wall and a lower wall, is provided. The fuel level measurement system includes a support member configured to be coupled between the upper wall and the lower wall, the support member configured to maintain a predetermined distance between the upper wall and the lower wall when the lower wall of the semi-rigid fuel tank is moved due to a force.

[0007] In addition to the foregoing, the described fuel level measurement system may include one or more of the following features: a fuel level sensor configured to couple to the upper wall of the semi-rigid fuel tank, wherein the fuel level sensor is configured to determine a fuel level in the fuel tank by sensing a distance to a top surface of the fuel level.

[0008] In another aspect, a fuel tank assembly is provided. The fuel tank assembly includes a semi-rigid fuel tank having an upper wall and a lower wall, and a support member coupled between the upper wall and the lower wall. The support member is configured to maintain a predetermined distance between the upper wall and the lower wall when the lower wall of the semi-rigid fuel tank is moved due to a force.

[0009] In addition to the foregoing, the described fuel tank assembly may include one or more of the following features: a fuel level sensor coupled to the upper wall of the semi-rigid fuel tank, wherein the fuel level sensor is configured to determine a fuel level in the fuel tank by sensing a distance to a top surface of the fuel level; a float configured to float at a top surface of a fuel level in the fuel tank, and a fuel level sensor coupled to the upper wall of the semi-rigid fuel tank and configured to determine the fuel level in the fuel tank by sensing a distance to the float; wherein the fuel level sensor is ultrasonic-based; wherein the fuel level sensor is light-based; wherein the support member is a rigid member having a first end and an opposite second end, the first end coupled to the upper wall and the second end coupled to the lower wall; a fuel delivery module configured to supply fuel to a vehicle engine; and wherein the rigid support member comprises a first rigid support member and a second rigid support member each coupled between the upper wall and the lower wall. [0010] In another aspect, a fuel level measurement system for a fuel tank assembly having a fuel tank having a lower wall and a low fuel reservoir disposed at least partially below the lower wall, the low fuel reservoir configured to define a space where fuel drains when the rest of the fuel tank is empty, the low fuel reservoir having a predetermined volume, is provided. The fuel level measurement system includes a low fuel sensor operably associated with the low fuel reservoir, the low fuel sensor defining a low fuel level activation point, and a controller in signal communication with the low fuel sensor. The controller is configured to receive a low fuel signal from the low fuel sensor when the fuel level in the fuel tank falls below the low fuel level activation point.

[0011] In addition to the foregoing, the described fuel level measurement system may include one or more of the following features: wherein the low fuel sensor is a positive temperature coefficient thermistor.

[0012] In another aspect, a fuel tank assembly is provided. The fuel tank assembly includes a fuel tank having a lower wall and a low fuel reservoir disposed at least partially below the lower wall, the low fuel reservoir configured to define a space where fuel drains when the rest of the fuel tank is empty, the low fuel reservoir having a predetermined volume. A low fuel sensor is operably associated with the low fuel reservoir, the low fuel sensor defining a low fuel level activation point.

[0013] In addition to the foregoing, the described fuel tank assembly may include one or more of the following features: a controller in signal communication with the low fuel sensor, wherein the controller is configured to receive a low fuel signal from the low fuel sensor when the fuel level in the fuel tank falls below the low fuel level activation point; wherein the controller determines a low fuel mileage limit based on the received low fuel signal and the predetermined volume; a baffle disposed at least partially over the low fuel reservoir and configured to prevent fuel slosh; wherein the baffle partially defines the space; wherein the low fuel sensor is a positive temperature coefficient thermistor; wherein the low fuel sensor is a single point sensor configured to set the low fuel level activation point; and a fuel delivery module configured to supply fuel to a vehicle engine.

[0014] In yet another aspect, a fuel tank assembly is provided. The fuel tank assembly includes a semi-rigid fuel tank having an upper wall and a lower wall, and a support member coupled between the upper wall and the lower wall. The support member is configured to maintain a predetermined distance between the upper wall and the lower wall when the lower wall of the semi-rigid fuel tank is moved due to a force. The fuel tank assembly can further include a low fuel reservoir disposed at least partially below the lower wall, the low fuel reservoir configured to define a space where fuel drains when the rest of the fuel tank is empty, the low fuel reservoir having a predetermined volume. A low fuel sensor is operabiy associated with the low fuel reservoir, the low fuel sensor defining a low fuel level activation point. A fuel level sensor coupled to the upper wall of the fuel tank, wherein the fuel level sensor is configured to determine a fuel level in the fuel tank by sensing a distance to a top surface of the fuel level.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0016] FIG. 1 is a schematic view of an example fuel tank assembly in accordance with the principles of the present disclosure; and

[0017] FIG. 2 is a schematic view of another example fuel tank assembly in accordance with the principles of the present disclosure.

DETAILED DESCRIPTION

[0018] With initial reference to FIG. 1 , an example fuel tank assembly 10 is shown. In the illustrated example, fuel tank assembly 10 is for a vehicle (not shown) such as an automobile. However, fuel tank assembly 10 may be utilized with various other vehicles or systems. Fuel tank assembly 10 generally includes a fuel tank 12, a fuel delivery module 14, a fuel level sensor 16, and one or more stays or support members 18.

[0019] The fuel tank 12 is configured to store a fuel that is utilized by the vehicle engine and/or other system (e.g., an emission system). In the illustrated example, the fuel tank 12 may be semi-rigid such that one or more wall portions of the fuel tank 12 can be moved when a force acts thereon. For example, a bottom wall 26 of the fuel tank 12 may move downwardly due to a pressure and/or fuel weight load acting thereon. Fuel delivery module 14 may include a fuel pump assembly (not shown) that includes one or more pumps for pressurizing and supplying fuel to fuel injectors of the vehicle engine (not shown).

[0020] The fuel level sensor 16 can be a top mounted sensor configured for coupling to an upper wall 20 of the fuel tank 12. The fuel level sensor 16 can be an electronic sensor configured to "shoot" or sense a distance to a top surface of the fuel in the tank 12 or to a support or float (not shown) configured to float on the surface of the fuel in the tank 12. For example, the fuel level sensor 16 may be ultrasonic-based, light- based, or any combination thereof. Moreover, fuel level sensor 16 may be any suitable sensor that enables assembly 10 to function as described herein.

[0021] Support member 18 includes a first end 22 and an opposite second end 24. The first end 22 is coupled to the fuel tank upper wall 20, and the second end is coupled to the bottom or lower wall 26 of the fuel tank 12. The support member 18 is a rigid member coupled between the upper wall 20 and the lower wall 26 such that movement of the lower wall 20, for example sagging, will similarly move the top wall. As such, support member 18 is configured to maintain a predetermined distance 'D' between the upper wall 20 and the lower wall 26 proximate the fuel level sensor 16. Accordingly, support member 18 can allow a top mounted fuel level sensor 16 to be utilized for accurate fuel level measurement even though movement of the semi-rigid fuel tank 12 occurs (e.g., sagging of the lower wall 26).

[0022] With reference to FIG. 2, an example fuel tank assembly 100 is shown. In the illustrated example, fuel tank assembly 100 is for a vehicle (not shown) such as an automobile. However, fuel tank assembly 100 may be utilized with various other vehicles or systems. The fuel tank assembly 100 generally includes a fuel tank 112, a fuel delivery module 1 14, a low fuel level sensor 116, and one or more baffles 1 18. Moreover, assembly 100 may include one or more features of the previously described fuel tank assembly 10 such as fuel level sensor 16 and support member(s) 18.

[0023] The fuel tank 112 is configured to store a fuel that is utilized by the vehicle engine and/or other system (e.g. , an emission system). The fuel tank 112 includes a depression or low fuel reservoir 120 that is disposed at least partially below a lower wall 122 of the fuel tank 112. The reservoir 120 defines a space or area 124 where fuel can drain when the rest of the fuel tank 112 is empty. The space 124 defined by reservoir 120 can have a predetermined volume, which can be used to determine a fuel volume contained therein. The baffle 1 18 is disposed at least partially over the reservoir 120 and is configured to prevent movement or slosh of the fuel contained therein. Fuel delivery module 114 may include a fuel pump assembly (not shown) that includes one or more pumps for pressurizing and supplying fuel to fuel injectors of the vehicle engine (not shown).

[0024] The low fuel sensor 116 is operably associated with and/or disposed at least partially within or proximate to the low fuel reservoir 120. The low fuel sensor 116 sends a signal or alert to a vehicle controller 126 when fuel in the predefined space is less than a sensor activation point 128. When the sensor 116 tripped, the controller 126 can subsequently determine how much fuel is left in the fuel tank 112 based on the predetermined volume in reservoir 120, which can enable the controller 126 or other system to determine or predict distance of travel until the fuel tank 112 is empty.

[0025] As used herein, the term controller refers to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.

[0026] The low fuel sensor 116 may be a positive temperature coefficient (PTC) thermistor or other single point sensor configured to accurately set the low fuel activation point 128. However, low fuel sensor 116 may be any suitable sensor that enables assembly 100 to function as described herein. Once the controller 126 receives a low fuel level signal indicating that the fuel level in the fuel tank 112 has dropped below the low fuel activation point 128, the controller 126 can log the indication and manage and/or calculate a low fuel mileage limit, which may then be displayed or indicated to a driver of the vehicle.

[0027] The foregoing description of the examples has been provided for purposes of illustration and description, ft is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular example are generally not limited to that particular example, but, where applicable, are interchangeable and can be used in a selected example, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.