CN109946024A - Leak testing components with nonlinear systems - Google Patents

Abstract

This disclosure relates to carry out leak-testing to component using nonlinear system.The disclosure relates generally to the system and method for carrying out leak-testing to component.The method and system of leak-testing is disclosed for the monitor of leak-testing arrangement and carried out to component (e.g., including the automobile component of transmission components, transmission assembly, engine components, engine assembly, battery pack or axis including dry component or through the pretreated component of oil) in various embodiments.

Description

Leak testing components with nonlinear systems

technical field

The present disclosure generally relates to systems and methods for leak testing components.

Background technique

Conduct transmission assembly leak testing or final leak testing to ensure proper assembly of components or to ensure that all sealing surfaces are functioning as intended. Leak detection is important for a variety of reasons. For example, a transmission fluid leak in the transmission assembly can severely impair the performance of the transmission assembly. There are several methods for testing components for leaks, such as pressure decay measurements, flow-based leak testing (such as measuring air mass flow), or tracer gas testing with helium. These test methods suffer from several issues that limit the effectiveness or efficiency of the test methods. For example, flow-based methods require that measurement/testing of a component be completed before the leak rate of the component can be determined. In other examples involving transmission assemblies, when oil is used to pretreat transmission components, the oil can cause random restrictions in the flow path during final leak testing. In addition to the fact that the presence or absence of the restriction is completely random during the test, the restriction will not remain consistent during the test because the transmission fluid can move and allow the passages to open and close randomly.

SUMMARY OF THE INVENTION

As disclosed in the various embodiments, the present disclosure addresses and overcomes the limitations of other leak testing methods. Disclosed in various embodiments are monitors for leak testing arrangements as well as for components (eg, automotive components including transmission components, transmission assemblies including dry components or oil pretreated components, engine components, engine assemblies, Methods and systems for leak testing battery packs or shafts).

In various embodiments, methods and systems are disclosed for leak testing a component comprising the steps of: connecting the component to a tank via a pair of conduits to equalize the pressure within the component and the tank; closing one of the conduits to induce airflow from the storage tank through another of the conduits to the component; and output a leak indication regarding the component based on a time between a peak and a predetermined value of the flow of the airflow. The method and system of various embodiments may further include the step of pressurizing the component prior to the connecting, or measuring the flow prior to the output.

In various embodiments, a monitor is disclosed for a leak testing arrangement comprising a pair of conduits connecting a component and a storage tank in parallel, the monitor comprising: a controller configured to After the pressure within the component and the tank has equilibrated, one of the conduits is closed to induce airflow from the tank through the other of the conduits to the component, based on the flow rate of the airflow between peak and reach. A leak indication on the component is output for the time between predetermined values.

In various embodiments, a leak testing system is disclosed comprising: a pair of conduits of different diameters connecting a component and a tank in parallel; a sensor disposed in the smaller of the conduits; and a control a device configured to close the other of the conduits to induce airflow from the storage tank through the smaller one of the conduits to the component, and outputting an indication of a leak with respect to the component based on the time between the peak and a predetermined value of the flow rate of airflow detected by the sensor.

Description of drawings

For a further understanding of the nature, objects and advantages of the present disclosure, reference should be made to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals refer to like elements, and wherein:

FIG. 1 is an exemplary graphical representation showing the behavior of a flowmeter and the fit of flow over time to a nonlinear system/model including a flow function and a leakage function when a component leaks.

FIG. 2 is an exemplary graphical representation showing the performance of a flowmeter when a component has a leak and a comparison to a nonlinear system/model without a leak.

Figure 3 shows a general schematic diagram of the method, system and monitor of various embodiments.

FIG. 4 is a flowchart including steps of a method, system and monitor of various embodiments.

5 is an exemplary graphical representation illustrating the steps of a method, system and monitor of various embodiments including start-up and testing of components.

6-13 are exemplary graphical representations of methods, systems and monitors illustrating various embodiments including testing of components.

Detailed ways

As required, specific embodiments of the present disclosure are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary and may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art.

All numerical amounts in this description indicating amounts of materials or reaction conditions and/or use conditions should be understood to be modified by the word "about" unless explicitly stated in the examples or otherwise. The first definition of an acronym or other abbreviation applies to all subsequent uses of the same abbreviation in this text, and mutatis mutandis applies to conventional grammatical changes of the originally defined abbreviation; and, unless specifically stated to the contrary, , otherwise the measure of the attribute is determined by the same technique as mentioned earlier or later for the same attribute.

It will also be understood that, as particular components and/or conditions may (certainly) vary, this disclosure is not limited to the specific embodiments and methods described below. Also, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting in any way.

The terms "approaching" and "approaching" are used interchangeably to determine that a point is near or at another point.

In various embodiments, monitors are disclosed for use in a leak testing arrangement and monitoring of components (eg, automotive components including transmission components, transmission assemblies including dry components or oil pretreated components, engine components, engine assemblies , battery pack or shaft) method and system for leak testing.

As disclosed in various embodiments, the present disclosure addresses and overcomes the limitations of other leak testing methods. Due to the volume of automotive components (such as transmissions), it may be more cost-effective to utilize specific physical relationships with respect to the transient response of gauges (such as flow sensors) when leak testing, without having to invest additional capital in additional test rigs (Test rigs typically need to wait for the flow to stabilize below an acceptable threshold). Since the volume of the transmission can be constant, the amount of time required to pressurize the interior of the transmission is also constant if the transmission is fully sealed (ie, there are no leaks). As shown in Figure 1, the components tested for leak rate have flow curves in which turbulence is induced to cause the flow to rise, peak and decay to steady state flow. This type of test is similar to a vehicle hitting a speed bump, causing the air flow measurement to rise, peak and decay to its steady state flow. By maintaining a constant fill volume, test pressure, and fill time, when there is no leak in the transmission, the peak flow caused by activation of the flow meter can be constant and rise proportionally based on the transmission leak rate. Therefore, once the peak flow has been established, an accurate prediction of the overall leak rate can be made. This predictive model is unique for each transmission configuration and sometimes even indeterminate if the air volume changes due to the addition or absence of components.

In this sense, this curve can be fitted to a nonlinear system such as:

in:

V is the volumetric flow rate that can be measured in standard cubic centimeters per minute (SCCM);

C ₁ , C ₂ , C ₃ and C ₄ are constants derived for each transmission tested;

t is the measured time in seconds;

_VL (t) is the leakage rate of the transmission, which may or may not change with respect to time during activation of the flow meter.

In the exemplary test of Figure 1, as time t approaches infinity, the leakage approaches its final actual value, or:

Typically, the leak rate will approach steady state relatively quickly compared to the recovery of the flowmeter's response. The larger the leakage rate, the more dominant the exponential coefficient of the leakage term _VL (t) will be relative to the other terms in the expression. If the leak rate is low or negligible, the nonlinear system/model is:

If the same model is applied to a part with a certain degree of apparent leakage, the correlation coefficient, which indicates the quality of the fit, decreases. Additionally, the derived constants can be significantly affected, resulting in a significantly longer function expressing the recovery rate of the flowmeter. Through sampling, it has been determined that for any transmission, only a small number of additional data samples beyond the peak are required to accurately derive the flow function. As a result, components can be tested and identified with acceptable or unacceptable leak rates in seconds rather than minutes. The methods, systems and monitors of various embodiments eliminate the need for time-consuming predictive model development associated with peak analysis. This allows for increased efficiency and allows more parts to be tested in a given time period.

As shown in FIG. 2, the methods, systems, and monitors of various embodiments may include measuring a flow curve for a predetermined period of time (eg, a period of time equal to the time peak flow is reached), and correlating the curve with a nonlinear system sex is assessed. Figure 2 shows a comparison of measured values of flow and flow curves derived from a nonlinear system.

FIG. 3 shows a general schematic diagram of the system and monitor 10 of various embodiments. As shown in FIG. 3 , component 20 is connected to catheter system 100 . A medium source 30, such as a gas (ie, shop air) or a liquid, is connected to the conduit system 100, and a storage tank 40 is connected to the conduit system 100. The conduit system 100 of the various embodiments can connect the component 20 to the media source 30 or the storage tank 40 so that a gas or liquid can flow between the component 20 and the source 30 or the storage tank 40 . The fill capacity or volume of the storage tank 40 may be greater than the fill capacity or volume of the component 20 .

The conduit system 100 of various embodiments includes a plurality of conduits 110 having holes connected to each other in a manner that enables gas or liquid to flow between the component 20 and the medium source 30 or storage tank 40 . In various embodiments, the plurality of conduits 110 include conduits 113 whose holes are smaller in diameter than other conduits 111 or conduits 112 whose holes are larger than the other conduits 111 . Alternatively, the bore diameter of the conduit 110 may be approximately the same as the bore diameter of the larger diameter conduit 112 . The larger diameter conduit 112 is also referred to as the bypass conduit or larger conduit 112 and the smaller diameter conduit 113 is also referred to as the smaller conduit. Utilizing larger conduits 112 in system 100 may reduce the time it takes to pressurize components 20 and utilizing smaller conduits 113 in system 100 may improve the ability to measure flow, which may allow for smaller leakage flows in components 20 test. Alternatively, catheter systems of other embodiments may include catheters whose bores are all the same or approximately the same diameter.

As shown in FIG. 3, the larger conduit 112 and the smaller conduit 113 are arranged in the conduit system 100 in a parallel arrangement.

The catheter system 100 of various embodiments also includes a sensor 120 and a flow/pressure regulator 130 .

The sensor 120 of various embodiments is configured to measure one or more physical or chemical properties within the catheter 110 or a bore of the catheter. For example, sensors 120 may include pressure indicators/meters/sensors 121 and flow indicators/meters/sensors configured to measure one or more physical or chemical properties (such as flow and pressure) within the bore of conduit 110 122. In various embodiments, the sensor 120 is capable of taking a measurement approximately every 0.1 seconds, 0.5 seconds, 1.0 seconds, 1.5 seconds, 2.0 seconds, 2.5 seconds, 3.0 seconds, 3.5 seconds, 4.0 seconds, 4.5 seconds, and 5.0 seconds. In various embodiments, the time that the sensor 120 takes a measurement is in the range between any two of the times listed above.

The flow/pressure regulator 130 of various embodiments is configured to control a parameter of the conduit 110 (such as flow or pressure within the bore of the conduit 110). Flow/pressure controller or regulator 130 may include various types of valves 131 and 132 (such as 3-way or 4-way valves) or other regulators (such as proportional flow controller 133 ) that can have different positions to direct flow . The proportional flow controller 133 may adjust the flow when the component 20 is about to be saturated/being pressurized with gas.

The system and monitor 10 of various embodiments also includes a controller 60 . Controller 60 is operably connected to sensor 120 and flow/pressure regulator 130 (lines 150, 160). In various embodiments, controller 60 can receive measurements from sensor 120 (line 160) and can control flow/pressure regulator 130 (line 150). The controller 60 of various embodiments also includes one or more non-transitory computer-readable storage media (implementation logic) or processors that are executed to receive measurements from the sensors 120 (ie, the Step 201 ), the method of controlling the flow/pressure regulator 130 (ie, step 202 in FIG. 4 ), and performing a leak test of the component 20 of any of the embodiments are operable.

FIG. 4 is a flowchart including the steps of the method, system and monitor 200 of various embodiments, and FIG. 5 is a flowchart illustrating the steps of the method, system and monitor 200 of the various embodiments (including start-up steps and leak testing of components 20 ) An exemplary graphical representation of . In various embodiments, the controller 60 also includes one or more non-transitory computer-readable storage media (implementation logic) or processors that execute the functions for initiating or executing the various embodiments shown in FIG. 4 . Steps 201 , 202 , 203 , 204 , 205 , 206 , 207 , 208 , 209 , 210 , 211 , 212 , 213 , 214 , 215 , 216 , 217 , 218 , 219 , 220 , 221 of method, system and monitor 200 , 222 and 223 are operable.

In step 201 of FIG. 4 , a leak test sequence is initiated in which component 20 is connected to conduit system 100 . In step 202, conduit system 100 of various embodiments is activated to pressurize component 20, wherein valves 131 and 132 are positioned to allow gas or air from plant compressed air 30 to flow through conduit 110 to component 20, The catheter 110 may include a smaller diameter catheter 113 and a larger diameter catheter 112 . In step 202, catheter system 100 may be configured to allow components 20 to be filled as quickly as possible to allow for continuous testing of multiple components. To minimize the time for pressurizing a component (eg, transmission), oversized tubing and an above-target pressure supply may be used in step 202, which is referred to as a "rapid fill phase." In step 202 , valve 131 is also positioned to prevent flow to tank 40 . As shown in FIG. 5 , from 0 to 3 seconds, activation of the conduit system 10 in step 202 results in increased airflow ( 301 , 302 ) through the conduits 110 including the smaller diameter conduit 113 and the larger diameter conduit 112 . This also results in an increase in pressure within component 20 (303). In various embodiments, the leak testing methods, systems and monitors of various embodiments include pressurizing the component 20 to a pressure above a predetermined target pressure. The target pressures for the various examples are approximately 3 pounds per square inch (psi) (20.68 kilopascals (kPa)); 3.1 psi (21.37 kPa); 3.2 psi (22.06 kPa); 3.3 psi (22.75 kPa); 3.4 psi (23.44 3.5psi(24.13kPa); 3.6psi(24.82kPa); 3.7psi(25.51kPa); 3.8psi(26.20kPa); 3.9psi(26.89kPa); 4psi(27.58kPa); 4.2psi(28.96kPa); 4.3psi(29.65kPa); 4.4psi(30.34kPa); 4.5psi(31.03kPa); 4.6psi(31.72kPa); 4.7psi(32.41kPa); 4.9 psi (33.78 kPa) and 5 psi (34.47 kPa). In various embodiments, the target pressure is in a range between any two of the pressures listed above. In various embodiments, the component 20 is pressurized to 4.2 psi (28.96 kPa) or more.

In various embodiments, the component is filled to a volume sufficient to decay the flow signal or decay the flow curve to a constant value.

In various embodiments, the methods, systems and monitors may further include the step of allowing the component to stabilize for a period of time sufficient to allow the system or conduit to stabilize the pressure within the component prior to connecting the component to the tank. As shown in step 203 of FIG. 4 , after the component is filled with gas above the target pressure, component 20 is allowed to stabilize for a period of time sufficient to allow the pressure within component 20 to stabilize/stabilize with the pressure within system 100 . In step 203 , the valve 131 may be configured/activated to stop the flow of the plant compressed air 30 to the system 100 or component 20 . As shown in FIG. 5 with respect to step 203, once the components are filled above the target pressure (304), the flow in the bypass conduit 112 and the smaller diameter conduit 113 of the system 100 is stabilized (305, 306) .

In various embodiments, the flow profile within the system is allowed to stabilize to a predetermined flow. Figure 5 shows that the flow curve (307) through the smaller diameter conduit 113 is operating below the predetermined flow or value (308) and the flow curve (309) through the bypass conduit 112 is below the predetermined flow or value (310). run.

In various embodiments, flow is monitored. Monitoring of various embodiments may include monitoring that the flow is operating below a predetermined flow or value to limit the effect on settling time. If the flow decay through the system 100 becomes unstable, this indicates that the component 20 has been overfilled.

In various embodiments, methods, systems, and monitors include connecting components to a storage tank for a first time period or saturation time. The first period of time for various embodiments is a time sufficient for the component to reach a certain pressure or thermal equilibrium. After component 20 and system 100 have stabilized, valve 131 is positioned or activated to open flow between tank 40 and component 20 in step 204 . The flow from the plant compressed air 30 remains closed. During the saturation time, the component 20 is connected to a storage tank 40, which may have a significantly larger volume than the component 20, so that the component 20 is returned to ambient target pressure and thermal equilibrium. The tank 40 is pressurized prior to connection with the component, and the pressure within the tank 40 of various embodiments is below the target pressure of the component 20 described above. The pressure in the storage tank for each example was approximately 3 psi (20.68 kPa); 3.1 psi (21.37 kPa); 3.2 psi (22.06 kPa); 3.3 psi (22.75 kPa); 3.4 psi (23.44 kPa); ); 3.6psi(24.82kPa); 3.7psi(25.51kPa); 3.8psi(26.20kPa); 3.9psi(26.89kPa); 4psi(27.58kPa); 4.3psi (29.65kPa); 4.4psi (30.34kPa); 4.5psi (31.03kPa); 4.6psi (31.72kPa); 4.7psi (32.41kPa); 4.8psi (33.09kPa); (34.47kPa). In various embodiments, the pressure within the storage tank is within a range between any two of the pressures listed above. In one embodiment, the pressure within storage tank 40 is approximately 4.0 psi (27.58 kPa). As shown in Figure 5, the component 20 exhibits an initial drop in pressure (312) when initially connected to the tank (311). The initial drop (312) is an indication that the pressure or temperature within component 20 has stabilized to equilibrium.

An example of a first time period is shown in FIG. 5 as the time between time 311 and time 313 .

In various embodiments, the peak flow or time to peak flow of the curve is determined by the time the component is pressurized and the first period of time. In various embodiments, methods, systems and monitors include the step of executing a containment algorithm that automatically or autonomously increases or decreases fill and settling times based on a running average of peak flow.

In various embodiments, methods, systems, and monitors include inducing turbulence within the connection to facilitate airflow from a storage tank (forming a flow profile), and measuring the flow profile for a second period of time. Gas may flow from tank 40 through conduit 110 to component 20 upon inducing turbulence within the connection. In one embodiment, during the second time period, gas flows through the smaller conduit 113 and the flow sensor 122 is used to measure the flow profile through the smaller conduit 113 . The second time period of various embodiments may include the time when the curve peaks, the time period ending between the time when the curve peaks and approaching the predetermined flow limit. In step 205 , the leak test begins, wherein flow from the storage tank 40 is directed through the smaller conduit 113 . Step 205 also includes positioning or activating valve 132 to shut off flow through larger conduit 112 . By shutting off flow through the larger conduit 112 , turbulent flow within the connection between the tank 40 and the component 20 can be induced, causing gas to flow from the tank 40 through the smaller conduit 113 to the component 20 . The methods, systems and monitors of various embodiments may also include the step of verifying that there is an initial rise in the flow curve. As shown in Figure 5, the bypass conduit 112 is closed (313) and the initial rise in the flow curve is verified (314). The methods, systems, and monitors of various embodiments may further include checking (315) the slope of the flow curve between the start and end of monitoring, wherein if the slope of the flow curve between the start and end of monitoring is greater than Pre-defined slope, then an additional check for part 20 filling or further filling of part 20 is done.

In various embodiments, the second time period is 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29, 29.5, 30, 30.5, 31, 31.5, 32, 32.5, 33, 33.5, 34, 34.5, 35, 35.5, 36, 36.5, 37, 37.5, 38, 38.5, 39, 39.5 and 40 seconds to finish. In various embodiments, the time at the end of the second time period is within the range between any two of the times listed above from the time when the curve peaks.

In steps 206 to 208, the flow profile of component 20 is measured up to a point near a predetermined flow limit. In step 207, the time to rise and reach peak flow ( _tp ) is calculated and recorded. In step 208, measure the flow curve through t _p until the flow decays below the upper limit. For example, measuring the time elapsed _tp may be a length of time equal to _tp . As shown in Figure 5, the flow curve rises (316), peaks (317) and decays to steady state flow (318).

In various embodiments, methods, systems, and monitors include fitting a flow curve to a nonlinear system, and making a correlation that brings the fit within predetermined thresholds. In step 209, the flow curve is modeled as an overdamped system, and the flow curve can be modeled as a nonlinear system, eg, as follows:

in:

V is the volume flow rate that can be measured in standard cubic centimeters per minute (SCCM);

C ₁ , C ₂ , C ₃ and C ₄ are constants derived for each tested transmission;

t is the measured time in seconds;

To verify the validity of the fit of the flow curve to the nonlinear system, the correlation of the fit is determined and compared to a predetermined threshold. In various embodiments, the correlating step includes at least one check to verify the validity of the fit.

In various embodiments, the correlating step includes a data fitting method that can be used to fit the measured flow curve to a nonlinear system. Data fitting methods may include a variety of regression methods, including: least squares regression/method or non-linear least squares regression/method. In step 210, when the r-square value (R ² ) calculated by the data fitting method is greater than the predetermined r-square lower limit, the correlation is within the predetermined threshold. In various embodiments, the predetermined r-square lower limit is approximately 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95 , 0.975, 0.99 and 1. In various embodiments, the predetermined lower r-square limit is a range between any two r-square limits listed above.

In various embodiments, the step of correlating includes calculating a theoretical time to peak flow and comparing the theoretical time to t _p , wherein if t _p is within an acceptable predetermined variation from the calculated theoretical time, then Fitting is valid.

In step 211, the theoretical time to reach the peak flow is calculated according to the following formula:

Among them, the nonlinear system is:

In various embodiments, as shown in step 212, the fit of the flow curve to the nonlinear system is determined to be valid if _tp is within an acceptable predetermined variation from the calculated theoretical time. Acceptable predetermined variations are approximately 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, 4, 4.25, 4.5, 4.75 and 5 seconds. In various embodiments, the acceptable predetermined variation is within a range between any two acceptable predetermined variations listed above. Another degree of effectiveness is obtained by solving a model for the time it takes to reach a particular flow, and comparing that time to the time at which the flow peaks. The ratio between the theoretical time for the air flow to be below the threshold and the time for the air flow to peak is consistent for the part with the lowest leakage. This ratio tends to increase as leakage increases.

In step 213, the correlation step may further include: if C ₁ , C ₂ , C ₃ and C ₄ are all greater than 0 (C ₁ , C ₂ , C ₃ , C ₄ >0), determining the flow curve to be nonlinear fit of the system.

In step 214, the methods, systems and monitors of various embodiments include when the curve is fitted to the nonlinear system, in response to the correlation being within a predetermined threshold, deriving from the fit a point in time at which the curve approaches a predetermined flow limit . The deriving step of various embodiments includes applying an iterative algorithm, such as the Newton-Raphson method, to determine the point in time at which the curve approaches a predetermined flow limit. In various embodiments, the deriving step includes applying an iterative algorithm that calculates a time point from a previously calculated time point until the newly calculated time point falls within a predetermined time change relative to the previously calculated time point. In other embodiments, the deriving step includes applying an iterative algorithm that calculates a time point from a previously calculated time point until the flow calculated from the newly calculated time point falls within a predetermined flow change relative to a predetermined flow limit. The solid lines shown in Figures 6 to 11 represent the time points derived from the fit of the flow curve to the nonlinear system.

In step 215, the methods, systems and monitors of various embodiments include calculating a ratio between the time point and _tp . The calculation of the ratio normalizes the change in _tp .

In various embodiments, methods, systems, and monitors include outputting an indication of a leak about a component based on the time between the flow of the airflow peaking and the flow of the airflow reaching a predetermined value. In one embodiment, the output includes: if the time point is less than a predetermined time limit, the component is identified as having an acceptable leak rate, and if the time point (t _L ) is greater than the predetermined time limit, the component is identified as having an acceptable leak rate Has an unacceptable leak rate. The predetermined time limit of various embodiments may be a range having a lower limit and an upper limit, wherein if the time point is less than the lower limit, the part is identified as having an acceptable leak rate, and if the time point is greater than the upper limit, the part is identified to have an unacceptable leak rate.

Step 216 emphasizes the upper and lower limits. The lower and upper bounds for the ratio test are determined empirically by testing several components and calculating probabilities based on the correlation between the ratio and leak rate. Identify models with different leak rates. For example, prepare an ideal model with no leaks by modifying parts to be airtight and leak-free. Other models are prepared based on prepared parts with known leak rates. For example, when preparing for the lower and upper limits of the transmission's leak rate, over 99% of transmissions with ratios below 7.5 are acceptable, and over 99% of transmissions with ratios greater than 10 have high leakage Rate. Based on such preparations, transmissions between 7.5 and 10.0 are a mix of good and bad transmissions and cannot be accurately judged. Thus, having certified components with known leak rates falling within the interval between 7.5 and 10.0 is understood to be close to the maximum leak limit or maximum allowable leak rate.

Step 216 includes determining whether the correlation is within a predetermined threshold, and, if the correlation is within the predetermined threshold (ie, the model is valid), determining whether _tL is greater than an upper limit (step 217) or less than a lower limit (step 218).

6 and 7 are examples of methods, systems and monitors 400, 400' for various embodiments of leak testing components. The flow profile 401 is measured at a predetermined time or second time period 402 . For this example, it is determined that the correlation is within a predetermined threshold (ie the model is valid). A point in time 407 when the curve approaches the predetermined flow limit 406 is derived (403). As shown, time point 407 is less than upper limit 405 and lower limit 404 . As indicated at step 218, the component will be identified as having an acceptable leak rate (222). The leak test example 400' of Fig. 7 is similar to the example 400 of Fig. 6 and also shows variable flow within the flow curve 401'. Even with variable flow, the correlation can be determined to be within a predetermined threshold (ie, the model is valid).

FIG. 8 is an example of a method, system and monitor 500 for various embodiments of leak testing components. The flow profile 501 is measured at a predetermined time or second time period 502 . For this example, it is determined that the correlation is within a predetermined threshold (ie the model is valid). A point in time 507 when the curve approaches the predetermined flow limit 506 is derived (503). As shown, time point 507 is greater than upper limit 505 and lower limit 504 . As indicated in step 217, the component will be identified as having an unacceptable leak rate (221).

In various embodiments, methods, systems and monitors include measuring a curve to the time when flow decays below a predetermined flow limit or near steady-state flow, and if flow decays below the predetermined flow limit, in response to the derived point in time Within the range, the part will be identified as having an acceptable leak rate. FIG. 9 is an example of a method, system and monitor 600 for various embodiments of leak testing components. The flow profile 601 is measured at a predetermined time or second time period 602 . For this example, it is determined that the correlation is within a predetermined threshold (ie the model is valid). The derived point in time 607 when the curve 603 approaches the predetermined flow limit 606 is between the upper limit 605 and the lower limit 604 . In steps 219 and 223, the flow profile is further measured until the flow decays to the predetermined flow limit, or if the flow decays to the predetermined flow limit, the flow profile is further measured. As shown in FIG. 9 , the flow curve 601 decays below the predetermined flow limit at a point 608 where the upper limit 605 and lower limit 604 are not reached. Since the component did not decay below the predetermined flow limit in step 220, the component tested in Figure 9 was identified as having an acceptable leak rate (step 222). The example 600' of FIG. 10 is similar to the example 600 of FIG. 9, but the point in time 608' when the flow curve 601' decays below the predetermined flow limit is between the upper limit 605 and the lower limit 604. The components tested in Figure 10 were also identified as having acceptable leak rates (step 222) as the components decayed below the predetermined flow limit at step 220.

FIG. 11 is an example of a method, system and monitor 700 for various embodiments of leak testing components. In FIG. 11 , the flow profile 701 is measured at a predetermined time or second time period 702 . For this example, it is determined that the correlation is within a predetermined threshold (ie the model is valid). The derived point in time 707 when the curve 703 approaches the predetermined flow limit 706 is between the upper limit 705 and the lower limit 704 . In steps 219 and 223, the flow profile is further measured when the flow decays to the predetermined flow limit, or if the flow decays to the predetermined flow limit, the flow profile is further measured. As shown in Figure 11, the flow curve 701 does not decay below the predetermined flow limit. Since the component did not decay below the predetermined flow limit 706 in step 220, the component is identified as having an unacceptable leak rate (step 221)

In various embodiments, methods, systems and monitors include measuring a curve to the time when flow decays below a predetermined flow limit or near steady state flow, and if flow decays below the predetermined flow limit, in response to the correlation being at a predetermined threshold Otherwise, components will be identified as having acceptable leak rates. The examples 800, 800' disclosed in Figures 12 and 13 involve steps 216 and 223, where it is determined that the correlation is not within a predetermined threshold (ie the model is invalid or the model is a bad model). In steps 219 and 223, the flow profile is further measured when the flow decays to the predetermined flow limit, or if the flow decays to the predetermined flow limit, the flow profile is further measured. In the example 800 of FIG. 12 , the flow curve 801 approaches ( 807 ) the predetermined flow limit 806 and decays below the predetermined flow limit 806 . The components tested in Figure 12 were also identified as having acceptable leak rates (step 222) due to the component decaying below the predetermined flow limit at step 220. In other aspects, in the example 800' of FIG. 13, the flow curve 801' Since the component did not decay below the predetermined limit 806 at step 220, the component in Figure 13 was identified as having an unacceptable leak rate (step 221).

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms. More particularly, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the present disclosure. Additionally, the features of various implementing embodiments may be combined to form further embodiments.

Claims (15)

1. A method comprising: Connect the component to the tank via a pair of conduits to equalize the pressure within the component and the tank; closing one of the conduits to induce airflow from the tank through the other of the conduits to the component; A leak indication for the component is output based on the time between the peak and the predetermined value of the flow rate of the airflow. 2. The method of claim 1, further comprising pressurizing the components prior to the connecting. 3. The method of claim 1, further comprising measuring the flow prior to the outputting. 4. The method of claim 1, wherein the closing comprises closing a valve in the one of the conduits. 5. The method of claim 1, wherein the conduits have different diameters. 6. The method of claim 5, wherein the diameter of the one of the conduits is greater than the diameter of the other of the conduits. 7. The method of claim 1, wherein the predetermined value is based on a size of the catheter. 8. The method of claim 1, wherein the component is an automotive component. 9. The method of claim 1, wherein the volume of the storage tank is greater than the volume of the component. 10. The method of claim 1, wherein the pressure within the tank is less than the pressure within the component prior to the connecting. 11. A monitor for a leak testing arrangement comprising a pair of conduits connecting a component and a tank in parallel, the monitor comprising: Controller, configured as: After the pressures in the component and the tank have equilibrated, closing one of the conduits to induce airflow from the tank through the other of the conduits to the component, based on airflow The flow outputs a leak indication for the component at the time between peaking and reaching a predetermined value. 12. The monitor of claim 11, wherein the diameter of the one of the conduits is greater than the diameter of the other of the conduits. 13. The monitor of claim 11, wherein the volume of the storage tank is greater than the volume of the component. 14. The monitor of claim 11, wherein the predetermined value is based on the size of the conduit. 15. A leak testing system comprising: A pair of conduits, of different diameters, connecting the components and the tank in parallel; a sensor, arranged in a smaller one of the conduits; Controller, configured as: After the pressures in the component and the tank have equilibrated, closing the other of the conduits to induce airflow from the tank through the smaller of the conduits to the component, Based on the time between reaching a peak value and a predetermined value of the flow rate of the airflow detected by the sensor, an indication of a leak for the component is output.