Abstract:
A probe operable to measure a fluid level including a tip movably mounted to a housing, the tip including a multiple of steps and a sensor mounted within the housing, the sensor selectively activated in response to movement of the tip toward the housing. A method of measuring a fluid within a chamber of a vehicle includes locating a probe with a tip including a multiple of steps into a fill port of a chamber, only one of the multiple of steps associated with the fill port; and pressing the probe toward the fill port such that a sensor within the probe is selectively activated in response to movement of the tip toward the housing, the sensor determining a distance to a fluid within the chamber.

Description:
BACKGROUND 
     The present disclosure relates to equipment useful in the manufacture and repair of a vehicle, and more particularly to measurement of fluid levels therein. 
     Various equipment useful in the manufacture and repair of a vehicle is often provided to confirm proper fluid fill levels within a chamber such as that within a vehicle transaxle. Confirmation has traditionally been performed with either fiber optic or air pressure probes. 
     Dependent on access, sufficient space may be provided for two fiber optic probes to confirm that the fluid fill level is between a desired upper and a lower fluid limit. Otherwise, access for a single fiber optic probe provides a go or no-go signal. Since fiber optic check probes operate via direct fluid contact, each probe is typically dedicated to a particular usage to avoid contamination between different fluid types, however, even if the fluid type is the same, a dedicated probe is required to verify each specific fluid level. Also, due in part to contact with the fluid, fiber optic probe elements are subject to wear that requires preventative maintenance to ensure proper functionality. 
     Air pressure probes utilize backpressure from the liquid within a chamber to detect the presence of an acceptable fluid volume. Air pressure probes require an airtight interface with the fluid to ensure proper operation that necessitates a dedicated probe specific to each fill port. Air pressure probes also result in fluid contact that again requires separate dedicated probes for each specific fluid type and fluid level. 
     Although effective, such conventional probes typically only confirm a threshold fluid level. Further, dedicated probes are required for each fluid type and level to be checked. 
     SUMMARY 
     A probe operable to measure a fluid level according to one disclosed non-limiting embodiment of the present disclosure includes a housing; a tip movably mounted to the housing, the tip including a multiple of steps; and a sensor mounted within the housing, the sensor selectively activated in response to movement of the tip toward the housing. 
     A fluid measurement system, according to another disclosed non-limiting embodiment of the present disclosure includes a first chamber with a first fill port; a second chamber with a second fill port of a diameter different than the first fill port; and a probe with a tip movably mounted to a housing, the tip including a multiple of steps of which only one of the multiple of steps is associated with the first fill port and only another one of the multiple of steps is associated with the second fill port. 
     A method of measuring a fluid within a chamber of a vehicle according to another disclosed non-limiting embodiment of the present disclosure includes locating a probe with a tip including a multiple of steps into a fill port of a chamber, only one of the multiple of steps associated with the fill port; and pressing the probe toward the fill port such that a sensor within the probe is selectively activated in response to movement of the tip toward the housing, the sensor determining a distance to a fluid within the chamber. 
     The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, the following description and drawings are intended to be exemplary in nature and non-limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various features will become apparent to those skilled in the art from the following detailed description of the disclosed non-limiting embodiment. The drawings that accompany the detailed description can be briefly described as follows: 
         FIG. 1  is a schematic view of a vehicle for use with a fluid level measurement probe system; 
         FIG. 2  is an expanded view of the fluid level measurement probe in use with a first chamber; 
         FIG. 3  is an expanded view of the fluid level measurement probe system according to one disclosed non-limiting embodiment; 
         FIG. 4  is an expanded view of the fluid level measurement probe system according to one disclosed non-limiting embodiment; 
         FIG. 5  is an expanded view of the fluid level measurement probe in use with a second chamber; 
         FIG. 6  is an expanded view of the fluid level measurement probe in use with a third chamber; 
         FIG. 7  is an expanded view of the fluid level measurement probe system in an activated configuration; and 
         FIG. 8  is a method of using the fluid level measurement probe system according to one disclosed non-limiting embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  schematically illustrates selected portions of a fluid measurement system  20  for a vehicle  22  with a chamber  24  that contains a fluid  26 . Such chambers  24  are often provided within, for example, a vehicle transaxle, differential, engine or other vehicle system. Further, other chambers may include tanks that contain other fluids such as hydraulic fluid, oils, or others. The chamber  24  may be filled through a fill port  28  that is often of different sizes and locations dependent on, for example, the vehicle or the vehicle system. The fill port  28  provides access for a probe  30  ( FIG. 2 ). 
     With reference to  FIG. 3 , the probe  30 , according to one disclosed non-limiting embodiment, generally includes a housing  32  that contains a sensor  34  for communication though a tip  36 . It should be appreciated that various sensors such as an ultrasonic sensor, a laser sensor, a triangulation laser sensor or other may be utilized. It should also be appreciated that although the tip  36  and sensor  34  are generally collinear with regard to the housing  32  along a common axis A, angled or other arrangements such as an offset tip arrangement in which the tip  36  is on an axis B parallel to the axis A of the housing  32  ( FIG. 4 ) may alternatively be provided. 
     The tip  36  includes a multiple of steps (three shown as  38 A,  38 B,  38 C). Each of the steps  38 A,  38 B,  38 C is sized with respect to a diameter of a specific fill port  28 A ( FIG. 2 ),  28 B ( FIG. 5 ),  28 C ( FIG. 6 ). In one example, the fill port  28 A may be about 10mm in diameter. Each of the steps  38 A,  38 B,  38 C is sized to be received into a fill port  28 A,  28 B,  28 C such that each step  38 A,  38 B,  38 C provides a particular individual distance datum. Each fill port  28 A,  28 B,  28 C is associated with, for example, a particular chamber  24 A,  24 B,  24 C such as that of a predetermined particular transaxle type, fluid volume, fluid type or other distinguishing characteristic. In one example, the chamber  24 A may be of about 300 ml. That is, each fill port  28 A,  28 B,  28 C is related to a particular chamber  24 A,  24 B,  24 C of a particular known volume. 
     Each of the multiple of steps  38 A,  38 B,  38 C increases in diameter from a distal end of the tip  36  toward the housing  32  to operate as a datum guide for an associated chamber  24 A,  24 B,  24 C to confirm a specific fluid level for that chamber  24 A,  24 B,  24 C. That is, an operator inserts the tip  36  into a fill port  28 A,  28 B,  28 C and the appropriate step  38 A,  38 B,  38 C necessarily interfaces therewith (see  FIGS. 2, 5, 6 ). It should be appreciated that any number of steps may be provided. 
     With continued reference to  FIG. 3 , the tip  36  is movably mounted to the housing  32  and biased therefrom. A bias member  40 , such as a spring, biases the tip  36  away from the housing  32  along the axis A. Pressure on the probe  30  when the tip  36  is within the port  28  that overcomes the bias of the bias member  40 , moves the tip  36  toward the housing  32 . It should be appreciated that the bias member  40  may be of strength to assure a positive interface between the tip  36  and the port  28  and that “toward” includes but is not limited to coaxial movement. 
     Movement of the tip  36  toward the housing  32  ( FIG. 7 ) selectively activates an actuator  42  such as a proximity switch, limit switch, micro switch or other that operates as a trigger for the sensor  34 . Insertion of the tip  36  into the fill port  28 A and pressure on the probe  30  drives the tip  36  toward the housing  32  to thereby activate the actuator  42  and operate the sensor  34 . That is, the sensor  34  is activated in response to proper probe  30  insertion into the fill port  28 A. It should be appreciated that various mechanical and/or electronic mechanisms may be utilized as a trigger for actuation of the sensor  34 . The sensor  34  fires and detects a distance to the fluid  26  for communication to a control subsystem  44 . 
     Proper probe  30  insertion facilitates confirmation of a proper reference datum so that data such as a distance (illustrated schematically by arrow dl) measured by the sensor  34  provides accurate fluid height determination for use by the control subsystem  44 . The sensor  34  determines the distance to the fluid  26  without direct contact with the fluid  26  such that the probe  30  may be used for multiple chambers  24  without fluid cross-contamination. One example type of sensor  34  measures distance to the fluid  26  and provides accuracy to about 1 mm. 
     The control subsystem  44  generally includes a control module  46  with a processor  48 , a memory  50 , and an interface  52 . The processor  48  may be any type of microprocessor having desired performance characteristics. The memory  50  may include any type of computer readable medium which stores the data and control algorithms described herein such as a fluid measurement check algorithm  54  ( FIG. 8 ). The functions of the algorithm  54  are disclosed in terms of functional block diagrams, and it should be understood by those skilled in the art with the benefit of this disclosure that these functions may be enacted in either dedicated hardware circuitry or programmed software routines capable of execution in a microprocessor based electronics control embodiment. Other operational software for the processor  48  may also be stored in the memory  50  to provide both manual and automatic Programmable Logic Controller (PLC) inputs. The interface  52  facilitates communication with other subsystems such as the sensor  34 . It should be appreciated that the control subsystem  34  may be centralized or distributed. It should also be appreciated that various control inputs may be alternatively or additionally provided. 
     With reference to  FIG. 8 , the control subsystem  44  receives the distance, e.g., dl, d 2 , d 3 , etc., measured by the sensor  34  (step  100 ) and translates the data to provide an accurate fluid volume determination based on predetermined chamber  24  features (step  102 ). “Translation” as defined herein may include logic or instructions within the control module  46  that utilizes data such as the type of vehicle  22 , transaxle volume, fill port position  28  and/or other data in combination with the distance measurement generated by the sensor  34  to determine a fluid volume within the specific chamber  24 . That is, the control subsystem  44  may automatically associate each step  38 A,  38 B,  38 C with the associated fill port  28 A,  28 B,  28 C in an automated environment such as an assembly line environment or may alternatively or additionally receive an operator input as to which step  38 A,  38 B,  38 C is to be the datum in, for example, a service environment. The resultant fluid volume may optionally then be compared and cross-checked with other assembly line systems (step  104 ) such as the assembly line fluid fill equipment (not shown), which typically have a volume dispensed display to confirm proper fluid fills. 
     The probe  30  detects the fluid  26  in the respective chamber  24  without direct contact with the fluid  26 . This allows for one single probe  30  to be used to measure/check fluid volume of various chambers  24  irrespective of the fluid type and also reduces the risk of fluid contamination. That is, the probe  30  is readily available for use with three example chambers  24 A,  24 B,  24 C, each of which have different fill port  28 A,  28 B,  28 C associated with the three steps  38 A,  38 B,  38 C. Furthermore, the fluid measurement check algorithm  54  may be modified via, for example, a software update, to permit volume calculations which relate one or more of the steps  38 A,  38 B,  38 C with still other fluid chambers  24 . The probe  30 , being non-contact, is also less subject to wear which minimizes— or eliminates-significant preventative maintenance as in the case of fiber optics. 
     The use of the terms “a” and “an” and “the” and similar references in the context of description (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or specifically contradicted by context. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity). All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. It should be appreciated that relative positional terms such as “forward,” “aft,” “upper,” “lower,” “above,” “below,” and the like are with reference to the normal operational attitude of the vehicle and should not be considered otherwise limiting. 
     Although the different non-limiting embodiments have specific illustrated components, the embodiments of this invention are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
     It should be appreciated that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be appreciated that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom. 
     Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present disclosure. 
     The foregoing description is exemplary rather than defined by the limitations within. Various non-limiting embodiments are disclosed herein, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims. It is therefore to be appreciated that within the scope of the appended claims, the disclosure may be practiced other than as specifically described. For that reason the appended claims should be studied to determine true scope and content.