Abstract: A system and method for testing partially assembled engines for possible oil leaks. The system includes engine pressurizing devices that are automatically controlled by a controller according to a predetermined control program based upon the engine model type being tested. The pressurizing devices introduce pressurized air into the engine oil system. A leak testing unit monitors the pressurized engine for pressure drops indicative of an oil seal leak. Air pressure leaks resulting from inherently air-porous EGR valves are compensated for by an EGR compensating unit, which provides pressurized air to an intake side of the EGR valve. The flow of pressurized air through the EGR compensating unit is monitored to determine whether there is a problem with the EGR valve.

Abstract: A method and apparatus for measuring leakage of a vehicle fuel system includes providing an apparatus having a gas source, a pressure meter and a reference orifice and connecting the apparatus to the fuel system. The fuel system is pressurized with the source. A first set of pressure measurements is obtained using the pressure meter with gas escaping the fuel system through leakage of the fuel system. A second set of pressure measurements is obtained with gas escaping the fuel system through leakage of the fuel system and through the reference orifice. An effect of fuel vapor pressure created by fuel in the vehicle fuel system may be measured. A leakage parameter of the fuel system may be calculated from the first and second sets of pressure measurements including compensating for the effect of fuel vapor pressure.

Abstract: A leak diagnostic strategy for an engine equipped with a high pressure common rail fuel system includes a plurality of separate leak lines. Each of the leak lines is constructed and positioned to capture fuel leaking from one of several different high pressure spaces associated with the fuel system. Once a leak is detected, the location of the leak can be diagnosed by opening different leak diagnostic ports until fuel is evacuated from the system. Each of the leak diagnostic ports is associated with one of the leak lines. The system allows for quick determination of a leak location without cumbersome testing or partial dismantlement of engine related subsystems and components.

Abstract: A diaphragm is uniformly and finely deformed by compressed air supplied from an electro-pneumatic regulator, so that test fluid is supplied in conformity with the deformation of the diaphragm. In this way, a flow quantity of the test fluid supplied from a fluid supply device to a measurement passage is accurately adjusted. Therefore, an accuracy of a flow accuracy check device is improved, and a leakage measurement accuracy at the time of measuring a leakage from a fuel injection valve with a flow measurement apparatus is improved. At the time of measuring the leakage from the fuel injection valve, the diaphragm is stopped at a balanced position where a force of the air supplied from the regulator and a resilient force of the diaphragm is balanced. Therefore, a change in a volume of the measurement passage, which would be otherwise caused by movement of the diaphragm, does not occur.

Abstract: An evaporated fuel leak detector detects leakage of an evaporated fuel generated in a fuel tank. The detector includes: a differential pressure valve, a pump for sucking a detection port side to reduce pressure on a fuel tank side, and pressure detection means for detecting pressure on a detection port side. The valve includes a detection port connecting to a fuel tank side, an atmosphere port opened to atmosphere, a pressure chamber and a valve member displaceable in accordance with differential pressure between the detection port and the pressure chamber for connecting and disconnecting a connection between the detection port and the atmosphere port. The valve member disconnects between the detection port and the atmosphere port in a case where pressure of the pressure chamber becomes larger than pressure of the detection port by a predetermined pressure.

Abstract: A canister includes a casing that has a tank port connected to a fuel tank, an atmospheric port connected to an atmospheric passage communicating with atmosphere, and a purge port connected to an intake passage of an engine. An adsorbent is charged in the casing for adsorbing fuel vapor. A support member defines an accommodation chamber in the casing. The support member supports the adsorbent. A pump is supported by the support member. The pump is accommodated in the accommodation chamber. The pump introduces atmospheric air into the accommodation chamber through the atmospheric passage. A motor is accommodated in the accommodation chamber. The motor drives the pump. A damping member is located between the pump and the support member for absorbing sound and vibration transmitted from the pump to the support member.

Abstract: A cap structure for a radiator used in vehicle is disclosed. The cap includes a main cap body, a connector shaft, and a leak-seal seat. The main cap body includes a metallic cap body and a heat-isolation covering body joined together using screw as a body. The connector shaft is screwed onto the leak-seal seat, and the connector shaft passes through the through hole of a metallic sleeve mounted on the heat-isolation covering body. The side of the protruded rim of the connector shaft urges the end face of the sleeve and a spring is used to mount the connector shaft onto the main cap body. The heat-isolation covering body with a thickness is mounted onto the metallic cap body and two screws are used to lock the metallic cap body onto the heat-isolation covering body to form a unit, and the end side of the covering body is provided with slip-proof teeth and the metallic sleeve is mounted onto the center circular hole.

Abstract: In a fuel vapor purge system, a blocked diagnosis zone is pressurized by an air pump, a pressure in the diagnosis zone at the time when the diagnosis zone is pressurized, and an occurrence of leakage in the diagnosis zone is judged based on the comparison between a curvature of a change curve of the pressure and a threshold.

Abstract: A filter housing assembly for exhaust applications and method of testing the same is provided. In one embodiment, the filter housing assembly includes a housing having a filter receiving aperture, a first air flow port configured to couple the housing to an exhaust system and a second air flow port sized to deliver a flow capable of providing at least 75 feet per minute of air flow through the filter receiving aperture. A filter element is sealingly disposed in the filter receiving aperture of the housing. A cap is provided that operably seals the second air flow port when not in use. In another embodiment, a method for testing a filter housing assembly for exhaust applications includes providing air through a filter element disposed in the housing in a direction opposite an operational air flow direction, leak testing the filter element from a roomside of the filter element, and, flowing air through the filter element after leak testing in the operational direction.

Abstract: A valve testing device and method for determining whether a fluid control valve, such as an automatic transmission valve, is operating acceptably. The device and method of the present invention passes pressurized fluid through the valve and to a flow measuring means where the flow rate of fluid through the valve can be measured. Because contamination within such a valve can contribute to unacceptable flow rate measurements, the device and method of the present invention can also pass purge fluid through the valve in a direction that is opposite to the normal flow of working fluid through the valve.

Abstract: A leak detecting system detects fuel gas leakage of a fuel tank. The detecting system includes a fuel pump, a jet pump, and a bent valve, which are disposed in the fuel tank. A fuel flow path system includes a relief line connected to the fuel pump for relieving an excess fuel, a relief flow path switching valve disposed in the relief line, and a sub-line for connecting the switching valve and the vent valve. An air flow path system includes a first air flow line to connect the vent valve to a canister, a second air flow line for connecting the first air flow line to the jet pump, and an air flow switching valve for switching communication between the first and second air flow lines. An inner pressure sensor is provided to the fuel tank for detecting an inner pressure of the fuel tank.

Abstract: A loose or missing fuel cap detection method for an evaporative emission control system of an automotive vehicle detects a loose or missing fuel cap based in part on whether fuel level changed. The method determines whether the fuel level changed, which is indicative of a refueling event. The method then determines if one or more leaks are present. If the fuel level changed and one or more leaks are present, the method determines that the fuel cap is loose or missing.

Abstract: A temperature controlled hydraulic fluid supply circuit (12) includes a first hydraulic fluid reservoir (18), that has an initial hydraulic fluid (20), and a temperature controlled housing (45). A second hydraulic fluid reservoir (26) is fluidically coupled to the first hydraulic fluid reservoir (18), resides within the temperature controlled housing (45), and has a controlled hydraulic fluid (14) that is supplied to a test device (16). A circulation device (60) circulates a temperature altering fluid (62) through the temperature controlled housing (45) and adjusts the temperature of the controlled hydraulic fluid (14).

Abstract: A leak-testing technique and apparatus for differential pressure sensor arrays is provided. A reference pressure sensor array is provided, wherein a seal is disposed between the reference pressure sensor array and a target differential pressure sensor array. A probe socket is utilized to communicate with each individual sensor in the reference pressure sensor array. The target pressure sensor array and the reference pressure sensor array are sealed via a pressure plate and plunger assembly. The target pressure sensor array, seal, and reference pressure sensor array are exposed to a first pressure. The target differential pressure sensor array, seal, and reference pressure sensor array are then exposed to a second pressure. The probe socket verifies that all reference pressure sensors continue to output the first pressure. If the probe socket identifies a reference pressure sensor that reads the second pressure, then the corresponding target pressure sensor is identified as being defective because of leakage.

Abstract: The invention relates generally to a system and method for testing fuel evaporative systems, and more particularly to a stand-alone tank tester system (and method) for testing vehicle fuel tank integrity. Furthermore, a self-contained calibration tank with switchable leak sizes for calibrating the tank tester to multiple leak sizes is provided. Constant flow and vacuum methods for testing fuel tank integrity are also provided.

Abstract: An inside of an evaporated fuel processing system including a fuel tank is closed after changing an internal pressure of the evaporated fuel processing system to a target pressure value. After the closing, a diagnostic section variably sets a start timing for calculating a pressure change within the evaporated fuel processing system based on a timing when the internal pressure of the evaporated fuel processing system changes from the target pressure value to a peak pressure value. Then, a change amount between the respective internal pressure values detected by a detector at the set start timing and at a termination timing, which comes after the start timing, is calculated. The diagnostic section diagnose a leak within the evaporated fuel processing system based on the calculated change amount. Thus, the variably set start timing allows the diagnosis time to be shortened.

Abstract: After a reference pressure using a reference hole is measured, a pressure in an evaporation path is measured. An ECU conducts failure diagnosis using, as a determination pressure for diagnosing presence/absence of a failure, a value obtained by correcting the reference pressure using the reference hole in a manner lowering the same by a predetermined amount, taking into account pressure lowering in the evaporation path due to condensation of fuel vapor at the time of adsorption in a canister when a vapor concentration in the evaporation path is high.

Abstract: Disclosed herein are methods for detecting a water leak in a locomotive engine cooling system comprising numerous components, each being a potential source of leakage of water. The method typically comprises performing at least one inspection providing an indication of a water leak from an engine cooling system of the locomotive. The step of performing at least one inspection may comprise at least one of several steps including performing a visual inspection to determine if water is leaking from a portion of the cooling system external to the engine; performing a visual inspection of exhaust of the engine to detect an indication of water vapor in the exhaust; performing a visual inspection to detect an indication of water leaking into an intake air manifold 30 of the engine; performing an engine oil analysis to detect water in the engine lubricant; reviewing a fault log history for the locomotive; and checking a level of a cooling system sight glass.

Abstract: In a method for testing the functional reliability of a fuel-tank venting valve which is provided in a tank system of a motor vehicle in particular, is connected to an intake manifold and is triggerable by a control unit, a pressure source is provided for testing the tank system for leaks by using excess pressure or a vacuum, and the test of the functional reliability of the fuel-tank venting valve is performed on the basis of at least one performance quantity of the pressure source. In order to achieve a short diagnostic time and a high degree of diagnostic certainty, the fuel-tank venting valve is triggered to open or close, and a certain change in pressure is implemented. The at least one performance quantity of the pressure source is detected, and a properly opening and closing fuel-tank venting valve is determined from the performance quantity thus detected.

Abstract: A leakage drain is used to provide an indication that leakage of a fluid has occurred within an engine. Previously, such leakage was detected by visual inspection of a retained drop at the outlet of a drain. With the present invention, a sensor arrangement comprising electrodes is located within or about the leakage drain whereby leakage fluid creates a film across those electrodes. Relative presence or absence or thickness of film causes variation in a detected electrical response (capacitance, reactance, resistance or impedance) and this variation is utilized in order to determine whether fluid leakage has occurred. Additionally, by time of flight analysis using electrostatic sensors it is possible to determine fluid flow rate. By analysis at different incident frequencies, a characteristic response for a particular type of leakage fluid is obtained. Thus, it is possible to deduce the type of leakage fluid as well as the rate of leakage.

Abstract: A leak detection system for a vehicle fuel tank includes a sensor that is responsive to a pressure within the fuel tank and that generates a pressure signal based thereon. A control module initiates an engine-off natural vacuum (EONV) test and determines a pressure change based on the pressure signal. The control module pauses the EONV test when the pressure change exceeds a pressure change threshold.

Abstract: A canister has: a canister body including an adsorbent case which is provided with an adsorption chamber filled with an adsorbent and a fuel steam introduction port, a purge port and an air communication port which are communicated with the adsorption chamber; and a filter body. The canister body and the filter body are communicated with each other through a communication passage, in which a leak detection valve is disposed to be detachable through an end opening formed to the communication passage.

Abstract: A fuel vapor leakage check module has a canister port which is provided so that the port can be opened to the air and is connected to the interior of a fuel tank through a canister for absorbing fuel vapor produced in the fuel tank. A pump depressurizes or pressurizes the interior of the fuel tank through the canister port. A connecting passage which is coaxially provided in the canister port, is connected to the canister port. The connecting passage is depressurized or pressurized by the pump. A standard orifice is coaxially provided in the connecting passage and reduces the passage area of the connecting passage.

Abstract: A signaling device for a marine vehicle having a fuel tank, a fuel level value detected in the fuel tank, and a blower to evacuate fuel fumes. The signaling device comprises: a fuel level variation detector; a refueling detector for detecting a fuel level variation corresponding to a refueling event; a refueling signal generator for generating a refueling signal when the refueling event is detected; and a refueling activator for activating the blower, and/or an indicator of refueling for the user, using the refueling signal. A signaling method for the marine vehicle comprising: detecting a variation of the fuel level value over time; detecting a fuel level increase in the variation to correspond to a refueling event; generating a refueling signal when the refueling event is detected; and activating the blower, and/or an indicator of refueling for the user, using the refueling signal.

Abstract: A method for detecting leaks in a fuel cell system that includes a hydrogen storage tank, a primary shut-off valve and a secondary shut-off valve in a supply line. At shut-down, the primary shut-off valve is closed and the stack is temporarily left operating. The pressure is measured in the supply line between the valves. When the measured pressure has reached a predetermined shut-down pressure, the secondary shut-off valve is closed. At the next system start-up, the pressure is measured before the shut-off valves are opened, and the measured pressure is compared with the stored pressure. If the current pressure measurement is lower than the stored pressure measurement, it is an indication that the supply line between the shut-off valves or the secondary valve leaks. If the measured pressure is higher than the stored pressure, it is an indication that the primary valve leaks.

Abstract: In a fuel vapor purge system, a diagnosis section inclusive of a fuel tank is pressurized from the generation of fuel vapor in the fuel tank has been finished after an operation of an engine was stopped, and the diagnosis is performed based on a pressure in the diagnosis section.

Abstract: A fuel vapor leak check module has a pump discharging an air through an outlet. When the fuel vapor check module is mounted on a vehicle, an outlet of the pump is opened downwardly in the gravity direction. A housing has an opening provided above the outlet. The foreign particles discharged from the outlet of the pump are deposited on the inner surface of the housing. The foreign particles hardly reach to the opening even if the discharged air pushes up the foreign particles. Thus, the foreign particles are separated from the discharged air by the gravity to avoid the scatter thereof.

Abstract: An inlet adapter includes a top portion threadingly engageable to a body portion, an expandable portion disposed adjacent the body portion, and a bolt threadingly engageable to the top portion, the bolt securing the expandable portion adjacent the body portion and compressing the expandable portion in association with rotation of the body portion about the top portion.

Abstract: A fuel vapor leak check module has a pressure sensor and a pump driven by a brushless motor. The pressure sensor is disposed at a place opposite to the inlet. A sensor room in which the pressure sensor is disposed communicates with the inlet of the pump through a pressure introducing passage and a pump-passage. Even if a pressure fluctuation arises at an inlet of the pump, a pressure fluctuation of the pressure in the fuel tank is restricted. Furthermore, the control circuit for the brushless motor is cooled by air flowing through a discharge passage. The sensor room is restricted from the discharge passage so that the discharged air hardly flows into the pressure room to enhance the accuracy of fuel vapor detection.

Abstract: A fuel injector testing system has a sleeve that mechanically isolates one or more test volumes in a fuel injector. The sleeve has interfaces on an inside surface. The interfaces sealably engage the O-rings on the fuel injector. An air displacement mechanism is connected to the sleeve. The air displacement mechanism adds or removes air from the test volumes. The pressure within each test volume is checked to determine whether there is any air leakage from the test volume.

Abstract: A fluid volume measuring apparatus for measuring volume of fluid flowing out of a measured object includes a passage member that defines a measurement passage. The measurement passage is filled with fluid, which is capable of moving in the measurement passage in accordance with volume of fluid flowing out of the measured object. The fluid filled in the measurement passage forms a bubble. The passage member has a translucent portion in a predetermined measurement range, in which the bubble displaces in accordance with volume of fluid flowing out of the object to be measured. The translucent portion is formed of a translucent material. Volume of fluid, which flows out of the measured object, is measured in accordance with displacement of the bubble.

Abstract: A valve control section of a diagnostic device for an evaporated fuel processing system closes an evaporated fuel processing system at closing timing at which a value of the internal pressure detected by an internal pressure detection section reaches a preset target pressure value after a negative pressure is introduced from an inlet system to the evaporated fuel processing system. A diagnostic section of the device compares the internal pressure value at diagnostic timing which is set so as to come after the closing timing with a preset criterion threshold value so as to execute a leak diagnosis of the evaporated fuel processing system. A calculation section of the device variably sets the diagnostic timing based on the intake negative pressure value detected by the intake pressure detection section. Thus, a time period required for an early diagnosis of the leak can be optimized.

Abstract: Pressure leakage in an evaporated fuel control system having a canister for absorbing evaporated fuel in a fuel tank is detected after an engine is stopped and a temperature in the system is stabilized. In the leakage detecting process, communication between the system and an atmospheric pressure is shut-off by closing an electromagnetic valve connected to the canister. The electromagnetic valve is closed by once supplying a full voltage thereto, and the closed-state is maintained by intermittently supplying a voltage in a duty-ratio-controlled manner or by supplying a lower voltage. Thus, power consumption for maintaining the closed-state is reduced.

Abstract: A leakage detecting apparatus includes a re-circulating passage for re-circulating an exhaust gas from an exhaust system to an air intake system in the engine, a re-circulating valve disposed in the re-circulating passage to control a flow rate of the re-circulating exhaust gas, and an A/F ratio sensor for detecting an A/F ratio of the exhaust system. An electronic control unit detects an operation amount of the re-circulating valve and calculates correlation between the operation amount and output of the A/F ratio sensor to determine a leakage in the re-circulating passage. The correlation is obtained by an inner product calculation of a vector of deviations of a time-sequence vector of the operation amount relative to a moving average and a vector of deviations of a time-sequence vector of the output of the A/F ratio sensor relative to a moving average.

Abstract: In a gas-tightness diagnosing apparatus for a fuel tank with an evaporative emission purge system, the gas-tightness diagnosing apparatus includes a pressurizing device, such as an air pump, which is applied to the gas-tightness diagnosing operation. The air pump itself is mounted in the fuel tank. In this construction, the layout space for the air pump can be easily allocated by applying space of the fuel tank. The whole assembly of the apparatus can be also formed compact and easily mounted on vehicles.

Abstract: The invention described and claimed in this application is for a fluid drip, tire tread, tire pressure, and foreign exhaust identification apparatus for a vehicle and the like. The inventive device includes a mat with stenciled regions drawn on the mat that identify various vehicle systems, which is placed beneath a vehicle, whereby each region defines a receiving area for identifying fluid drips, particulate, or excessive emissions from a vehicle system and a tire platform comprised of a deformable material for measuring the tire pressure and tread depth.

Abstract: A fuel system and a method of method of managing fuel vapor pressure in the fuel system. The fuel system a fuel tank having a headspace, a fuel vapor collection canister in fluid communication with the headspace, a purge valve, and a fuel vapor pressure management apparatus. The method includes performing leak detection on the headspace, and preventing a flow of fluid through an elastic diaphragm during leak detection. The elastic diaphragm includes at least one opening through which passes the flow of fluid. And the preventing the flow of fluid includes a first portion of the elastic diaphragm sealingly engaging a second portion of the elastic diaphragm. The method further includes relieving excess negative pressure in the headspace and relieving excess positive pressure in the headspace by fluid flow in different directions along the same flow path that includes the opening in the diaphragm.

Abstract: In a device and a method for measuring path lengths, particularly of brushes in sliding contacts, an air stream having a regularly fluctuating pressure is provided by a pump and conducted via an air supply line and a nozzle to an object to be measured. The object is disposed so that its length or position affects the flow resistance of passing air. A consequent pressure drop in the supply line is determined with a pressure sensor, and an evaluation unit computes, in particular from the difference between maximum and minimum air pressure, a length of the object as a function of the pressure difference. In another embodiment of the invention, pressurized air is supplied from a pump to an object to be measured, and a sensor is disposed to detect a pressure change when the object has attained a predetermined length.

Abstract: An evaporative emission leak detection system provides for detecting a leakage of a fuel vapor evaporating in a fuel tank by using a pressure difference between an inside and outside of the fuel tank. The system includes a pump for providing the pressure difference between the inside and outside of the fuel tank, a brushless motor for operating the pump, a first passage connecting to the fuel tank, a second passage connecting to the outside of the fuel tank, and a switching device for switching connections between the pump and at least one of the first passage and the second passage. The first passage has an adsorbent for adsorbing the fuel vapor. This system ensures a long life time and high accuracy of the leak detection.

Abstract: An apparatus, system and method of establishing a threshold for a leak detection test that is performed on a headspace of a fuel system. A fuel vapor pressure management apparatus includes a housing, a pressure operable device, and a sensor. The housing defines an interior chamber. The pressure operable device separates the interior chamber into first and second portions, and includes a poppet that moves along an axis and a seal that is adapted to cooperatively engage the poppet. A first arrangement of the pressure operable device occurs during the leak detection test when the seal is in a first deformed configuration. A sensor detects the first arrangement of the pressure operable device during the leak detection test. And a processor is coupled to the sensor and reduces sensitivity of the fuel vapor pressure management apparatus during the leak detection test.

Abstract: A method for detecting a missing or improperly installed fuel cap on a vehicle includes a first leak test that detects a leak in an evaporative emissions system of a vehicle. A refueling test detects a refueling of the vehicle when the first leak test detects the leak. A fuel cap indicator in the vehicle is activated when the first leak test detects the leak and the refueling test detects the refueling. The fuel cap indicator is deactivated after a predetermined time period. The fuel cap indicator remains deactivated when a predetermined number of leak tests consecutively detect the leak. The fuel cap indicator is deactivated when an occupant of the vehicle indicates that a fuel cap of the vehicle is properly installed. The occupant activates an actuator on an instrument panel of the vehicle to indicate the fuel cap is properly installed.

Abstract: An evaporated fuel purge system has a fuel tank, an adsorption filter and a purge control valve. The evaporated fuel purge system is pressurized and depressurized through a venting flow path by a pump, so that the state of leakage therefrom is thereby inspected. For this inspection, a motor unit for driving the pump which applies or reduces pressure, an in-vehicle battery and a voltage control circuit which controls a battery voltage to a predetermined voltage and supplies the motor unit with a current are provided. A switchover valve is integrated with the pump, the motor and the like into a single module.

Abstract: A system for estimating a quantity of parasitic leakage of a fluid from a fluid collection unit includes a pressure sensor and a control circuit. The pressure sensor is coupled to the fluid collection unit and configured to produce a pressure value indicative of the pressure of the fluid collection unit. The control circuit is operable to determine a change in pressure value of the fluid collection unit and estimate the quantity of parasitic leakage based on the change in pressure value. The control circuit may also be operable to determine a bulk modulus value of the fluid and estimate the quantity of parasitic leakage based on the change in pressure value and the bulk modulus value.

Abstract: A fuel vapor leakage inspection apparatus utilizes a fuel tank, an adsorption container which houses an adsorbent for adsorbing fuel vapor generated in the fuel tank, and an exhaust device for communicating between the adsorption container and an intake pipe. Furthermore, the apparatus utilizes a pressure means that pressurizes or depressurizes a fuel vapor path formed from the fuel tank through the adsorption container to the exhaust device. A leakage detection means detects leakage from the fuel vapor path after the fuel vapor path is pressurized or depressurized by the pressure means while a calculation means calculates an amount of fuel vapor adsorbed, and a control means determines if the pressure means should execute leakage inspection of the fuel vapor path in accordance with the amount of the fuel vapor calculated by the calculation means.

Abstract: An apparatus for detecting fuel-vapor gas leaks that includes a jet pump (8) that introduces outside air into and pressurizes a vapor purge system including a fuel tank (1) by gasoline flow from a fuel pump (2); an internal pressure sensor (14) for measuring vapor purge system internal pressure, an open/close controllable reference orifice (21) that causes leakage through a reference leak hole; and a storage device for storing as an initial curve pressure changes during pressurization by the jet pump (8) for a predetermined time period, with the reference orifice (21) alone opened. The device can accurately detect leakage even while an internal combustion engine is running because it judges leak presence/absence by comparing a time series in a pressure curve obtained by jet pump (8) pressurization over the predetermined time period while idling with the vapor purge system completely shut-off, with a time series in the initial curve.

Abstract: A method of tank leak diagnosis in a tank ventilation device including a fuel tank which is connected at least indirectly through a storage and tank ventilation valve with a suction pipe of an internal combustion engine of the vehicle, with the storage having an aeration conduit with a check valve, includes performing a tank leak diagnosis by a negative pressure after turning off of the internal combustion engine; and producing the negative pressure in the fuel tank immediately before the turning off of the internal combustion engine.

Abstract: A particulate filter system is provided including an exhaust system transporting emissions from an engine. A filter such as a diesel particulate filter is disposed in the exhaust system. An acoustic sensor is associated with the exhaust system for detecting one or more frequencies passing through the filter. The frequency corresponds to a filter state indicative of a clean, full, loading, or failed filter. One or more acoustic sensors may fluidly or mechanically coupled to portions of the exhaust system to determine the frequency caused by the exhaust flow through the filter. The acoustic emissions from the filter may be used to compare to a known filter state to determine the present filter state. Alternatively, more sophisticated mathematical approaches may be used in which processed filter information is compared to a known filter state to determine the present filter state.

Abstract: In a method and an arrangement for checking the tightness of a vessel (10), especially of a tank-venting system of a motor vehicle, the vessel (10) is charged with a pressure generated by a motor-driven pressure source (30) and the motor current is determined. A reference leak (36) is selectively driven by a switchover valve (32) and is charged with a corresponding pressure and the motor current is determined. The determined electrical characteristic quantity and the determined reference characteristic quantity are compared and a conclusion is drawn therefrom as to the presence of a leak. To prevent the entry of moisture into the pressure source (30), it is provided that at least the pressure source (30) is heated intermittently. The heating takes place preferably by driving the switchover valve (32) at a suitable pulse duty factor. To prevent the entrance of moisture into the pressure source (30), a check valve (44) is provided and is suitably mounted in the connecting part of the pressure source (30).

Abstract: A test stand for cylinder head components of an internal combustion engine includes at least one combustion or pressure chamber. The test stand supplies a hydraulic fluid to the chamber, and controls the pressure of the hydraulic fluid to simulate pressure cycles in the chamber. The test stand controls the pressure with at least one source of high-pressure hydraulic fluid, the high-pressure being at an adjustable and constant level, at least one solenoid valve per chamber, receiving hydraulic fluid from the high-pressure source, and automatically drives each solenoid valve as a function of the pressure in the chamber and a set-point pressure, so that each solenoid valve feeds this chamber with hydraulic fluid the pressure of which is controlled at any time by the solenoid valve and simulates predetermined pressure cycles as a function of time.

Abstract: A fuel vapor pressure management apparatus for a fuel system performs leak detection on a headspace of the fuel system, performs excess negative pressure relief of the headspace, and performs excess positive pressure relief of the headspace. The fuel vapor pressure management apparatus includes a diaphragm that is deformable between a nearly undeformed configuration that is associated with performing leak detection, a first deformed configuration that is associated with performing excess negative pressure relief, and a second deformed configuration that is associated with performing excess positive pressure relief. A first fluid flow through the diaphragm occurs when the diaphragm is in the first deformed configuration. A second fluid flow through the diaphragm occurs when the diaphragm is in the second deformed configuration, and the second fluid flow is opposite to the first fluid flow.