Leak testing components using nonlinear systems

Abstract

The present disclosure relates to leak testing components using nonlinear systems. The present disclosure generally relates to systems and methods for leak testing components. In various embodiments, a monitor for a leak testing arrangement and a method and system for leak testing a component (e.g., an automotive component including a transmission component, a transmission assembly including a dry component or an oil-pretreated component, an engine component, an engine assembly, a battery pack, or an axle) are disclosed.

Description

Technical Field

[0001] The present disclosure generally relates to systems and methods for leak testing components. Background Art

[0002] A transmission assembly leak test or final leak test is performed to ensure the correct assembly of the components or to ensure that all sealing surfaces function as expected. Leak detection is important for a variety of reasons. For example, a transmission fluid leak in a transmission assembly can seriously impair the performance of the transmission assembly. There are several methods for testing component leaks, such as pressure decay measurements, flow-based leak tests (such as measuring air mass flow), or tracer gas tests using helium. These test methods have several problems that limit the effectiveness or efficiency of the test methods. For example, flow-based methods require that the measurement / test of the component be completed before the leakage rate of the component can be determined. In other examples involving transmission assemblies, when the transmission components are pre-treated with oil, the oil can cause random restrictions in the flow path during the final leak test. In addition to the fact that the presence or absence of restrictions is completely random during the test, the restriction will not remain consistent during the test because the transmission fluid can move and allow the channel to open and close randomly. Summary of the invention

[0003] As disclosed in various embodiments, the present disclosure addresses and overcomes limitations of other leak testing methods. In various embodiments, a monitor for a leak testing arrangement and a method and system for leak testing a component (e.g., an automotive component including a transmission component, a transmission assembly including a dry component or an oil-pretreated component, an engine component, an engine assembly, a battery pack, or an axle) are disclosed.

[0004] In various embodiments, a method and system for leak testing a component are disclosed, including the steps of: connecting the component to a tank via a pair of conduits to balance the pressure in 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; and outputting a leak indication about the component based on the time between the flow rate of the airflow reaching a peak value and reaching a predetermined value. The methods and systems of various embodiments may also include the steps of: pressurizing the component before the connection, or measuring the flow rate before the output.

[0005] In various embodiments, a monitor for a leak testing arrangement is disclosed, the leak testing arrangement comprising a pair of conduits connecting a component and a tank in parallel, the monitor comprising: a controller configured to close one of the conduits after the pressures within the component and the tank have been balanced to induce airflow from the tank through the other of the conduits to the component, and output a leak indication about the component based on the time between the flow rate of the airflow reaching a peak value and reaching a predetermined value.

[0006] In various embodiments, a leak testing system is disclosed, comprising: a pair of conduits having different diameters, connecting a component and a tank in parallel; a sensor disposed in a smaller one of the conduits; and a controller configured to close the other of the conduits after the pressures in the component and the tank have been balanced to induce airflow from the tank through the smaller one of the conduits to the component, and output a leak indication about the component based on the time between the flow rate of the airflow detected by the sensor reaching a peak value and a predetermined value. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] 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, in which like reference numerals represent like elements, and in which:

[0008] Figure 1 is an exemplary graphical representation showing how a flow meter behaves when a component has a leak and the fit of the flow rate over time to a nonlinear system / model including a flow function and a leakage function.

[0009] Figure 2 is an exemplary graphical representation showing how a flow meter behaves when a component has a leak and a comparison to a non-linear system / model when there is no leak.

[0010] Figure 3 An overall schematic diagram of the methods, systems, and monitors of various embodiments is shown.

[0011] Figure 4 is a flow chart including steps of the methods, systems, and monitors of various embodiments.

[0012] Figure 5 is an exemplary graphical representation showing steps of methods, systems, and monitors of various embodiments including startup and testing of components.

[0013] Figures 6 to 13 are exemplary graphical representations of methods, systems, and monitors illustrating various embodiments including testing of components. DETAILED DESCRIPTION

[0014] As desired, specific embodiments of the present disclosure are disclosed herein; however, it will be understood that the disclosed embodiments are merely exemplary and may be implemented in various forms and alternative forms. The drawings are not necessarily drawn to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art.

[0015] Except in the examples or where otherwise expressly indicated, all numerical quantities in this description expressing amounts of material or reaction conditions and / or conditions of use are to be understood as modified by the word "about". The first definition of an acronym or other abbreviation applies to all subsequent uses of the same abbreviation herein and to conventional grammatical variations of the initially defined abbreviation, mutatis mutandis; and, unless specifically indicated to the contrary, measurements of properties are determined by the same techniques as previously or later mentioned for the same property.

[0016] It will also be understood that the present disclosure is not limited to the specific embodiments and methods described below, as specific components and / or conditions will (certainly) vary. In addition, the terminology used herein is only for the purpose of describing specific embodiments and is not intended to be limiting in any way.

[0017] The terms "approaching" and "close to" are used interchangeably to determine that a point is near or at another point.

[0018] In various embodiments, a monitor for a leak testing arrangement and a method and system for leak testing a component (e.g., an automotive component including a transmission component, a transmission assembly including a dry component or an oil-pretreated component, an engine component, an engine assembly, a battery pack, or an axle) are disclosed.

[0019] As disclosed in various embodiments, the present disclosure addresses and overcomes limitations of other leak testing methods. Due to the volume of automotive components (such as a transmission), it can be more cost-effective to utilize specific physical relationships regarding the transient response of instrumentation (such as a flow sensor) when leak testing, without having to invest additional funds in additional test rigs (which are typically required to wait for the flow to stabilize below an acceptable threshold). Since the volume of the transmission can be constant, if the transmission is completely sealed (i.e., no leaks), the amount of time required to pressurize the interior of the transmission is also constant. Figure 1As shown, the component being tested for leak rate has a flow curve where turbulence is induced causing the flow to rise, peak, and decay to a 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, the peak flow caused by the activation of the flow meter can be constant when no leaks are present in the transmission and rise proportionally based on the transmission's leak rate. Therefore, once the peak flow has been established, an accurate prediction of the overall leak rate can be made. This prediction model is unique to each transmission configuration and is sometimes even indeterminate if the air volume changes due to the addition or loss of components.

[0020] In this sense, it is possible to fit this curve to nonlinear systems, such as:

[0021]

[0022] in:

[0023] V is the volume flow rate which can be measured in standard cubic centimeters per minute (SCCM);

[0024] C1, C2, C3, and C4 are constants derived for each transmission tested;

[0025] t is the time measured in seconds;

[0026] V L (t) is the leakage rate of the transmission, which may or may not change with respect to time during startup of the flow meter.

[0027] exist Figure 1 In an exemplary test of , as time t approaches infinity, the leakage approaches its final actual value, or:

[0028]

[0029] Typically, the leak rate will approach steady state relatively quickly compared to the recovery of the flow meter's response. The larger the leak rate, the larger the leak term V L The exponential coefficient of (t) will become more dominant relative to the other terms in the expression. If the leakage rate is low or negligible, the nonlinear system / model is:

[0030]

[0031] If the same model is applied to a component with a significant degree of leakage, the correlation coefficient indicating the quality of the fit is reduced. In addition, the derived constants are significantly affected, resulting in a significantly longer function for expressing the recovery rate of the flow meter. Through sampling, it has been determined that for any transmission, only a small number of additional data samples beyond the peak value are required to accurately derive the flow function. Therefore, components can be tested and identified as having acceptable or unacceptable leakage 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 components to be tested in a given period of time.

[0032] like Figure 2 As shown, 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 to reach peak flow) and evaluating the relevance of the curve to the nonlinear system. Figure 2 A comparison of the flow derived from the nonlinear system with the measured values ​​of the flow curve is shown.

[0033] Figure 3 1 shows an overall schematic diagram of the system and monitor 10 of various embodiments. Figure 3 As shown, the component 20 is connected to the conduit system 100. A medium source 30, such as gas (i.e., shop air) or 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 various embodiments can connect the component 20 to the medium source 30 or storage tank 40, so that the gas or liquid can flow between the component 20 and the source 30 or storage tank 40. The filling capacity or volume of the storage tank 40 may be greater than the filling capacity or volume of the component 20.

[0034] The conduit system 100 of various embodiments includes a plurality of conduits 110 having holes, and the plurality of conduits 110 are connected to each other in a manner that allows gas or liquid to flow between the component 20 and the medium source 30 or the storage tank 40. In various embodiments, the plurality of conduits 110 include a conduit 113 whose hole diameter is smaller than that of other conduits 111 or a conduit 112 whose hole diameter is larger than that of other conduits 111. Alternatively, the hole diameter of the conduit 110 may be substantially the same as the hole diameter of the conduit 112 with a larger diameter. The conduit 112 with a larger diameter is also referred to as a bypass conduit or a larger conduit 112, and the conduit 113 with a smaller diameter is also referred to as a smaller conduit. Using the larger conduit 112 in the system 100 can reduce the time for pressurizing the component 20, and using the smaller conduit 113 in the system 100 can improve the ability to measure flow, which can allow for detection of smaller leakage flows in the component 20. Alternatively, the conduit system of other embodiments may include conduits whose holes have the same or substantially the same hole diameters.

[0035] like Figure 3 As shown, larger conduits 112 and smaller conduits 113 are arranged in a parallel arrangement within conduit system 100 .

[0036] The catheter system 100 of various embodiments further includes a sensor 120 and a flow / pressure regulator 130 .

[0037] The sensor 120 of various embodiments is configured to measure one or more physical or chemical properties within the conduit 110 or the bore of the conduit. For example, the sensor 120 may include a pressure indicator / meter / sensor 121 and a flow indicator / meter / sensor 122 configured to measure one or more physical or chemical properties (such as flow and pressure) within the bore of the conduit 110. 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 at which the sensor 120 takes a measurement is within the range between any two of the times listed above.

[0038] The flow / pressure regulator 130 of various embodiments is configured to control a parameter of the conduit 110, such as the flow or pressure within the bore of the conduit 110. The flow / pressure controller or regulator 130 may include various types of valves 131 and 132, such as 3-way valves or 4-way valves, or other regulators, such as a proportional flow controller 133, that can have different positions to direct the flow. The proportional flow controller 133 may adjust the flow when the component 20 is about to be saturated / pressurized with gas.

[0039] The system and monitor 10 of various embodiments also include a controller 60. The controller 60 is operably connected to the sensor 120 and the flow / pressure regulator 130 (lines 150, 160). In various embodiments, the controller 60 is capable of receiving measurements from the sensor 120 (line 160) and is capable of controlling the flow / pressure regulator 130 (line 150). The controller 60 of various embodiments also includes one or more non-transitory computer-readable storage media (implementing logic) or processors that, when executed, receive measurements from the sensor 120 (i.e., Figure 4 Step 201 in the flow rate / pressure regulator 130 (ie, Figure 4 The method of leak testing the component 20 of any embodiment is operable when performing step 202 of the embodiment.

[0040] Figure 4 is a flow chart including steps of the method, system, and monitor 200 of various embodiments, Figure 52 is an exemplary graphical representation of the steps of the method, system, and monitor 200 of various embodiments, including the startup steps and leak testing of the component 20. In various embodiments, the controller 60 also includes one or more non-transitory computer-readable storage media (implementing logic) or processors, which execute the steps for starting or performing such as Figure 4 The methods, systems, and monitors 200 of the various illustrated embodiments are operable at any one of steps 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, and 223.

[0041] exist Figure 4 In step 201, a leak test sequence is initiated, wherein component 20 is connected to conduit system 100. In step 202, conduit system 100 of various embodiments is enabled to pressurize component 20, wherein valves 131 and 132 are positioned to allow gas or air from factory compressed air 30 to flow to component 20 through conduit 110, which may include a smaller diameter conduit 113 and a larger diameter conduit 112. In step 202, conduit system 100 may be configured to allow component 20 to be filled as quickly as possible to allow for continuous testing of multiple components. In order to minimize the time to pressurize a component (e.g., a transmission), oversized piping and above-target pressure supplies may be used in step 202, which is referred to as a "fast fill phase." In step 202, valve 131 is also positioned to block flow to tank 40. As Figure 5As shown, from 0 to 3 seconds, activation of the conduit system 10 in step 202 causes an increase in airflow (301, 302) through the conduit 110, which includes the smaller diameter conduit 113 and the larger diameter conduit 112. This also causes an increase in pressure (303) within the component 20. 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 embodiments 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 kPa); 3.5 psi (24.13 kPa); 3.6 psi (24.82 kPa); 3.7 psi (25.51 kPa); 3.8 psi (26.20 kPa); 3.9 psi (26.89 kPa); 4psi (27.58 kPa); 4.1psi (28.27 kPa); 4.2psi (28.96 kPa); 4.3psi (29.65 kPa); 4.4psi (30.34 kPa); 4.5psi (31.03 kPa); 4.6psi (31.72 kPa); 4.7psi (32.41 kPa); 4.8psi (33.09 kPa); 4.9psi (33.78 kPa) and 5psi (34.47 kPa). In various embodiments, the target pressure is within a range between any two of the pressures listed above. In various embodiments, component 20 is pressurized to 4.2psi (28.96 kPa) or above.

[0042] In various embodiments, the component is filled to a volume sufficient to attenuate the flow signal or to decay the flow curve to a constant.

[0043] 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 pressure within the component to stabilize using the system or conduit before connecting the component to the tank. Figure 4 As shown in step 203 of the present invention, after the component is filled with gas to above the target pressure, the component 20 is allowed to stabilize for a period of time sufficient to allow the pressure within the component 20 to stabilize / stabilize with the pressure within the system 100. In step 203, the valve 131 can be configured / enabled to stop the flow of compressed plant air 30 to the system 100 or the component 20. Figure 5 As shown in relation to step 203 , once the components are filled above the target pressure ( 304 ), the flows within the bypass conduit 112 and the smaller diameter conduit 113 of the system 100 are stabilized ( 305 , 306 ).

[0044] In various embodiments, the flow profile within the system is allowed to stabilize to a predetermined flow. Figure 5 The flow curve (307) through the smaller diameter conduit 113 is shown to operate below a predetermined flow rate or value (308), and the flow curve (309) through the bypass conduit 112 is shown to operate below a predetermined flow rate or value (310).

[0045] In various embodiments, the flow rate is monitored. Monitoring of various embodiments may include monitoring the flow rate to run below a predetermined flow rate or value to limit the impact on the stabilization time. If the flow rate decay through the system 100 becomes unstable, this indicates that the component 20 has been overfilled.

[0046] In various embodiments, methods, systems and monitors include connecting the component to the tank and continuing for a first time period or saturation time. The first time period of various embodiments is a time sufficient for the component to reach a certain pressure or thermal equilibrium. After the component 20 and the system 100 have stabilized, in step 204, the valve 131 is positioned or enabled to open the flow between the tank 40 and the component 20. The flow from the factory compressed air 30 remains closed. During the saturation time, the component 20 is connected to the tank 40, which may have a volume significantly larger than the component 20, so that the component 20 returns to the target pressure and thermal equilibrium of the environment. The tank 40 is pressurized before being connected to the component, and the pressure in the tank 40 of various embodiments is lower than the above-mentioned target pressure of the component 20. The pressure in the storage tank of each embodiment is approximately 3psi (20.68kPa); 3.1psi (21.37kPa); 3.2psi (22.06kPa); 3.3psi (22.75kPa); 3.4psi (23.44kPa); 3.5psi (24.13kPa); 3.6psi (24.82kPa); 3.7psi (25.51kPa); 3.8psi (26.20kPa); 3.9psi (26.89kPa); 4psi (27.58kPa); 4.1psi (28.27kPa); 4.2psi (28.96kPa); 4.3psi (29.65kPa); 4.4psi (30.34kPa); 4.5psi (31.03kPa); 4.6psi (31.72kPa); 4.7psi (32.41kPa); 4.8psi (33.09kPa); 4.9psi (33.78kPa) and 5psi (34.47kPa). In various embodiments, the pressure in the tank is within a range between any two of the pressures listed above. In one embodiment, the pressure in the tank 40 is approximately 4.0psi (27.58kPa). Figure 5As shown, the component 20 shows 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 the component 20 has stabilized to equilibrium.

[0047] An example of the first time period is Figure 5 The time between time 311 and time 313 is shown in FIG.

[0048] In various embodiments, the peak flow of the curve or the time to peak flow is determined by the time the component is pressurized and the first time period. In various embodiments, the methods, systems and monitors include the step of executing a closed algorithm that automatically or autonomously increases or decreases fill and stabilization times based on a running average of the peak flow.

[0049] In various embodiments, the method, system and monitor include inducing turbulence in the connection to promote gas flow from the tank (forming a flow curve), and measuring the flow curve for a second time period. When turbulence in the connection is induced, gas can flow from the tank 40 through the conduit 110 to the component 20. In one embodiment, during the second time period, the gas flows through the smaller conduit 113 and the flow curve through the smaller conduit 113 is measured using the flow sensor 122. The second time period of various embodiments may include the time when the curve reaches a peak, and the time period ends between the time when the curve reaches a peak and approaches a predetermined flow limit. In step 205, the leak test begins, wherein the flow from the tank 40 is directed through the smaller conduit 113. Step 205 also includes positioning or enabling the valve 132 to close the flow through the larger conduit 112. By closing the flow through the larger conduit 112, turbulence in the connection between the tank 40 and the component 20 can be induced, causing the gas to flow from the tank 40 through the smaller conduit 113 to the component 20. The method, system and monitor of various embodiments may also include a step of verifying that there is an initial rise in the flow curve. like Figure 5 As shown, 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 also include checking the slope of the flow curve between the start and the end of the monitoring (315), wherein if the slope of the flow curve between the start and the end of the monitoring is greater than a predefined slope, an additional check is completed for filling of the component 20 or for further filling of the component 20.

[0050] 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, 37.5,38,38.5,39,39.5 and 40 seconds. In various embodiments, the time at which the second time period ends is within the range between any two times listed above from the time when the curve reaches a peak.

[0051] In steps 206 to 208, the flow curve of the component 20 is measured until a point close to the predetermined flow limit. In step 207, the time to rise and reach the peak flow (t p ). In step 208, the measurement is performed after t p The flow curve when the flow rate decays below the upper limit. For example, the measurement after t p The time can be equal to t p The length of time. Figure 5 As shown, the flow curve rises (316), reaches a peak (317), and decays to a steady state flow (318).

[0052] In various embodiments, the method, system and monitor include fitting the flow curve to a nonlinear system and performing an association such that the fit is within a predetermined threshold. In step 209, the flow curve is modeled as an overdamped system, and the flow curve may be modeled to a nonlinear system, for example, as follows:

[0053]

[0054] in:

[0055] V is the volume flow rate which can be measured in standard cubic centimeters per minute (SCCM);

[0056] C1, C2, C3, and C4 are constants derived for each transmission tested;

[0057] t is the time measured in seconds;

[0058] To verify the validity of the fit of the flow curve to the non-linear system, a correlation of the fit is determined and compared to a predetermined threshold. In various embodiments, the correlation step comprises at least one check for verifying the validity of the fit.

[0059] In various embodiments, the correlation step includes a data fitting method that can be used to fit the measured flow curve to a nonlinear system. The data fitting method can include a variety of regression methods, including: least squares regression / method or nonlinear least squares regression / method. In step 210, when the r-squared value (R 2 ) is greater than a predetermined r-squared lower limit, then the correlation is within a predetermined threshold. In various embodiments, the predetermined r-squared 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 r-squared lower limit is the range between any two of the r-squared limits listed above.

[0060] In various embodiments, the correlation step includes calculating a theoretical time to reach peak flow and comparing the theoretical time to t p For comparison, if t p The fit is valid if it is within an acceptable predetermined variation from the calculated theoretical time.

[0061] In step 211, the theoretical time to reach the peak flow rate is calculated according to the following formula:

[0062]

[0063] The nonlinear system is:

[0064]

[0065] In various embodiments, as shown in step 212, if t pThe fit of the flow curve to the nonlinear system is determined to be valid if it is within an acceptable predetermined variation relative to the calculated theoretical time. The acceptable predetermined variation is 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 the range between any two of the acceptable predetermined variations listed above. Another degree of validity is obtained by solving a model for the time required to reach a specific flow rate and comparing the time to the peak flow rate. The ratio between the theoretical time for the air flow rate to reach below the threshold and the time for the air flow rate to reach the peak is consistent for the components with the lowest leakage. As the leakage increases, this ratio also tends to increase.

[0066] In step 213 , the correlation step may further include: if C1 , C2, C3 and C4 are all greater than 0 (C1 , C2, C3, C4>0), then determining the fit of the flow curve to the nonlinear system.

[0067] 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 time point at which the curve approaches a predetermined flow limit. The deriving step of various embodiments includes applying an iterative algorithm (such as a Newton-Raphson method) to determine the time point at which the curve approaches the predetermined flow limit. In various embodiments, the deriving step includes applying an iterative algorithm that calculates time points from previously calculated time points until the newly calculated time points fall within a predetermined time variation relative to the previously calculated time points. In other embodiments, the deriving step includes applying an iterative algorithm that calculates time points from previously calculated time points until the flow calculated from the newly calculated time points falls within a predetermined flow variation relative to the predetermined flow limit. Figures 6 to 11 The solid lines shown in represent the time points derived from the fit of the flow curve to the nonlinear system.

[0068] In step 215, the methods, systems and monitors of various embodiments include calculating the time point and t p The ratio is calculated so that t p Normalize the changes.

[0069] In various embodiments, methods, systems, and monitors include outputting a leak indication about a component based on the time between the flow rate of the gas flow reaching a peak value and the flow rate of the gas flow 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, if the time point (tL ) is greater than a predetermined time limit, the component is identified as having an unacceptable leakage rate. The predetermined time limit of various embodiments may be a range with a lower limit and an upper limit, wherein if the time point is less than the lower limit, the component is identified as having an acceptable leakage rate, and if the time point is greater than the upper limit, the component is identified as having an unacceptable leakage rate.

[0070] Step 216 emphasizes the upper and lower limits. The lower and upper limits for the ratio test are empirically determined by testing several components and calculating the probability based on the correlation between the ratio and the leakage rate. Models with different leakage rates are determined. For example, an ideal model with no leakage is prepared by modifying the component to be sealed and leak-free. Other models are prepared based on the prepared components with known leakage rates. For example, when preparing the lower and upper limits for the leakage rate of the transmission, more than 99% of the transmissions with a ratio lower than 7.5 are acceptable, and more than 99% of the transmissions with a ratio greater than 10 have high leakage rates. Based on such preparation, the transmissions between 7.5 and 10.0 are a mixture of good transmissions and bad transmissions, and therefore cannot be accurately judged. Therefore, certified components with known leakage rates falling within the interval between 7.5 and 10.0 are understood to be close to the maximum leakage limit or the maximum allowable leakage rate.

[0071] 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 t L Whether it is greater than the upper limit (step 217) or whether it is less than the lower limit (step 218).

[0072] Figure 6 and Figure 7 400 ′ are examples of methods, systems, and monitors 400 , 400 ′ for various embodiments of leak testing a component. A flow curve 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 (i.e., the model is valid). A time point 407 is derived ( 403 ) when the curve approaches a predetermined flow limit 406. As shown, the time point 407 is less than the upper limit 405 and the lower limit 404. As indicated in step 218, the component will be identified as having an acceptable leak rate ( 222 ). Figure 7 The leak test example 400' is similar to Figure 6 4 and also shows a variable flow rate within the flow curve 401 '. Even with the variable flow rate, it can still be determined that the correlation is within a predetermined threshold (ie, the model is valid).

[0073] Figure 82 is an example of a method, system, and monitor 500 for various embodiments of leak testing a component. A flow curve 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 (i.e., the model is valid). A time point 507 is derived (503) when the curve approaches a predetermined flow limit 506. As shown, the time point 507 is greater than the upper limit 505 and the lower limit 504. As indicated in step 217, the component will be identified as having an unacceptable leak rate (221).

[0074] In various embodiments, methods, systems, and monitors include measuring a curve to the time when the flow decays below a predetermined flow limit or approaches a steady state flow, and if the flow decays below the predetermined flow limit, responsive to the derived time point being within a range, the component will be identified as having an acceptable leak rate. Fig. 9 6 is an example of a method, system, and monitor 600 for various embodiments of a leak test component. A flow curve 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 (i.e., the model is valid). The derived time point 607 when the curve 603 approaches a predetermined flow limit 606 is between an upper limit 605 and a lower limit 604. In steps 219 and 223, the flow curve is further measured until the flow decays to the predetermined flow limit, or if the flow decays to the predetermined flow limit, the flow distribution curve is further measured. As Fig. 9 As shown, the flow curve 601 decays below the predetermined flow limit at point 608 before reaching the upper limit 605 and the lower limit 604. Since the component does not decay below the predetermined flow limit in step 220, Fig. 9 The component being tested is identified as having an acceptable leak rate (step 222). Fig.10 An example of 600' is similar to Fig. 9 Example 600, but the time point 608' when the flow curve 601' decays below the predetermined flow limit is between the upper limit 605 and the lower limit 604. Since the component decays below the predetermined flow limit in step 220, Fig.10 The components tested in are also identified as having acceptable leak rates (step 222).

[0075] Fig.11 is an example of a method, system, and monitor 700 for various embodiments of leak testing components. Fig.11In step 219 and step 223, the flow curve 701 is measured at a predetermined time or second time period 702. For this example, it is determined that the correlation is within the predetermined threshold (i.e., the model is valid). The derived time point 707 when the curve 703 approaches the predetermined flow limit 706 is between the upper limit 705 and the lower limit 704. In step 219 and step 223, the flow curve is further measured when the flow decays to the predetermined flow limit, or if the flow decays to the predetermined flow limit. Fig.11 As shown, the flow curve 701 does not decay below the predetermined flow limit. Since the component does not decay below the predetermined flow limit 706 in step 220, the component is identified as having an unacceptable leakage rate (step 221).

[0076] In various embodiments, methods, systems, and monitors include measuring a curve to the time when the flow decays below a predetermined flow limit or approaches a steady state flow, and if the flow decays below the predetermined flow limit, in response to the correlation being outside a predetermined threshold, the component will be identified as having an acceptable leak rate. Fig.12 and Fig.13 The examples 800, 800' disclosed in the examples 800, 800' involve steps 216 and 223, wherein it is determined that the correlation is not within a predetermined threshold (i.e., the model is invalid or the model is a bad model). In steps 219 and 223, the flow curve is further measured until the flow decays to a predetermined flow limit, or if the flow decays to a predetermined flow limit, the flow curve is further measured. Fig.12 In the example 800, the flow curve 801 approaches (807) a predetermined flow limit 806 and decays below the predetermined flow limit 806. Since the component decays below the predetermined flow limit at step 220, Fig.12 The components tested in are also identified as having acceptable leak rates (step 222). Fig.13 In the example 800', the flow curve 801' does not decay below the predetermined limit 806. Since the component does not decay below the predetermined limit 806 in step 220, Fig.13 A component in is identified as having an unacceptable leak rate (step 221).

[0077] Although exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms. More specifically, the words used in the specification are descriptive rather than restrictive, and it is understood that various changes may be made without departing from the spirit and scope of the present disclosure. In addition, the features of the various implemented embodiments may be combined to form further embodiments.

Claims

1. A method for testing leakage, comprising: connecting the component to the tank via a pair of conduits to balance the pressure in the component and the tank; closing one of the conduits to induce a flow of gas from the tank through another of the conduits to the component; Determine the time when the measured flow rate of the airflow reaches a peak value, perform nonlinear fitting on the measured flow rate of the airflow, deduce the time when the flow rate of the airflow reaches a predetermined value through the nonlinear fitting, and output a leakage indication about the component based on a time period between the time when the flow rate of the airflow reaches a peak value and the time when the derived flow rate of the airflow reaches the predetermined value.

2. The method according to claim 1, further comprising: The components are pressurized prior to the connecting.

3. The method according to claim 1, wherein: The closing comprises closing a valve within the one of the conduits.

4. The method according to claim 1, wherein: The conduits have different diameters.

5. The method according to claim 4, wherein: The one of the conduits has a diameter greater than a diameter of the other of the conduits.

6. The method according to claim 1, wherein: The predetermined value is based on the size of the catheter.

7. The method according to claim 1, wherein: The component is an automobile component.

8. The method according to claim 1, wherein: The volume of the tank is greater than the volume of the component.

9. The method according to claim 1, wherein: Prior to the connection, the pressure in the tank is lower than the pressure in the component.

10. A monitor for a leak testing arrangement comprising a pair of conduits connecting a component and a tank in parallel, the monitor comprising: The controller is configured as: After the pressures in the component and the tank have equalized, closing one of the conduits to induce a flow of gas from the tank through the other of the conduits to the component, Determine the time when the measured flow rate of the airflow reaches a peak value, perform nonlinear fitting on the measured flow rate of the airflow, deduce the time when the flow rate of the airflow reaches a predetermined value through the nonlinear fitting, and output a leakage indication about the component based on a time period between the time when the flow rate of the airflow reaches a peak value and the time when the derived flow rate of the airflow reaches the predetermined value.

11. The monitor according to claim 10, wherein: The one of the conduits has a diameter greater than a diameter of the other of the conduits.

12. The monitor according to claim 10, wherein: The volume of the tank is greater than the volume of the component.

13. The monitor of claim 10, wherein: The predetermined value is based on the size of the catheter.

14. A leak testing system, comprising: a pair of conduits, having different diameters, connecting the components and the tank in parallel; a sensor disposed in a smaller one of the conduits; The controller is configured as: After the pressures in the component and the tank have equalized, closing the other of the conduits to induce a flow of gas from the tank through the smaller of the conduits to the component, Determine the time when the flow rate of the airflow detected by the sensor reaches a peak value, and perform nonlinear fitting on the flow rate of the airflow detected by the sensor, deduce the time when the flow rate of the airflow reaches a predetermined value through the nonlinear fitting, and, based on the time period between the time when the flow rate of the airflow reaches a peak value and the time when the derived flow rate of the airflow reaches the predetermined value, output a leakage indication about the component.

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