Abstract: A sensor unit for a three-axis accelerometer enabling reduction in chip size. The sensor unit is connected to an accelerometer that detects a plurality of acceleration values for a plurality of axis directions. The sensor unit includes a correction value generation circuit that sequentially generates a plurality of correction values for correcting the plurality of acceleration values. A correction circuit is connected to the correction value generation circuit to sequentially correct the plurality of acceleration values with a plurality of correction values and generate a plurality of corrected acceleration values.

Abstract: In a micro-electromechanical structure of semiconductor material, a detection structure is formed by a stator and by a rotor, which are mobile with respect to one another in presence of an external stress and are subject to thermal stress; a compensation structure of a micro-electromechanical type, subject to thermal stress and invariant with respect to the external stress, is connected to the detection structure thereby the micro-electromechanical structure supplies an output signal correlated to the external stress and compensated in temperature.

Abstract: An acceleration sensor device includes: a substrate; and an acceleration sensor chip including an acceleration sensor element which has a weight portion arranged to swing according to acceleration applied, and a seating portion which supports the acceleration sensor element, the acceleration sensor chip being mounted on the substrate. A cushion member is interposed between the seating portion and the substrate, which absorbs any thermal stress occurring when the seating portion and the substrate undergo thermal expansion or thermal contraction.

Abstract: A method is disclosed in this invention for compensating a temperature dependent variation of an offset Voffset and sensitivity Vsensitivity parameters of an accelerometer. The method includes steps of a) Measuring a Sensitivity Vsensitivity(T0) and an Offset Voffset(T0) at a room temperature T0 to input to a microprocessor to calculate two tilt angles ?1 and ?2 in placing the accelerometer in a furnace for adjusting a controllable temperature therein; b) Keeping the accelerometer at the fixed tilt angle ?1 and adjusting the temperature of the furnace for measuring an output voltage at ?1 Vo(T, ?1) and keeping the accelerometer at another fixed tilt angle ?2 and adjusting the temperature of the furnace for measuring an output voltage at ?2 Vo(T, ?2); and c) solving equations to obtain the offset Voffset and sensitivity Vsensitivity parameters at different temperatures and storing these parameters in the microprocessor.

Abstract: In a method of setting temperature characteristics of an angular velocity sensor, temperature characteristics of a detuning frequency are acquired. The detuning frequency is a frequency difference between an oscillation frequency of an oscillation circuit including a piezoelectric vibrator and a frequency of a voltage of the piezoelectric vibrator caused by the Coriolis force. The sensitivity to the detuning frequency is acquired. The temperature characteristics of a detection phase are acquired. The detection phase is a phase difference between a Coriolis signal phase that corresponds to a phase angle of a voltage signal and an oscillation signal phase of the oscillation circuit. The sensitivity to the detection phase is acquired. The amount of phase shift of the detection phase is determined so that the change in sensitivity caused by the change in the detuning frequency with temperature is controlled using the change in sensitivity caused by the change in the detection phase with temperature.

Abstract: The acceleration measurement system has a first thermal cell optimized in sensitivity and a second thermal cell optimized in passband, which cells are connected to inputs of a servo-control loop including an amplifier presenting gain that varies as a function of input signal frequency.

Abstract: A temperature compensation circuit having satisfactory linearity, a trimming circuit including a plurality of temperature gradients, and an acceleration detector having a wide applicable temperature range. A plurality of resistor elements R1 to R4, R5 to R8, R21 to R24, R25 to R28 are connected in series between a power supply voltage line and a ground voltage line. Resistor elements R9 to R14 are connected in series between connection nodes N1 and N3. Resistor elements R29 to R34 are connected in series between connection nodes N2 and N4. The resistor elements R1, R2, R4, R5, R7 to R14, R24, R25 have negative temperature coefficients. The resistor elements R3, R6, R21 to R23, R26 to R34 have positive temperature coefficients. An output terminal NT5 connects a connection node of the resistor elements R13 and R14 and a connection node of the resistor elements R30 and R29.

Abstract: A detector is made up of a semiconductor integrated circuit in a part, and the semiconductor integrated circuit includes a driving circuit, an AC amplifier, a detection circuit and an amplifier circuit. An input resistor that is connected to input terminals of an operational amplifier includes an internal input resistor made up of a semiconductor integrated circuit element and an external input resistor made up of an external discrete component connected to each other in parallel. Temperature characteristics of an angular velocity sensor is compensated by a temperature coefficient (?3) that is a combination of a temperature coefficient (?1) of the internal input resistor and a temperature coefficient (?2) of the external input resistor.

Abstract: An angular velocity measuring device (1) includes a first sensor (2) (vibration gyro) and a second sensor (3) (gas rate gyro). The detection output of the first sensor (2) is inputted to a high pass filter (4). Output of the filter (4) is stored and held in time series in a memory (10). Subtraction processing means (11) successively executes processing of subtracting the output of the filter (4) ?v?(t?tsd) before a predetermined time tsd from the output of the filter (4) ?v?(1). The value thus obtained is successively added to the output of the second sensor (3) ?g(t) by addition processing means (12) so as to obtain the measurement value of the angular velocity. Thus, it is possible to provide an angular velocity measuring device capable of giving an angular velocity measurement value having a high response and stability at a reasonable cost.

Abstract: An inertia sensor unit having a detecting element, a signal processor being constituted as an element separate from the detecting element, for at least amplifying signals output from the detecting element, and an inertia sensor mounted to a detection object for detecting acceleration or angular velocity of the detection object as an inertial force of the detection object to output electrical signals changing according to the inertial force, includes: a first temperature detecting element for detecting the temperature of the signal processor, a second temperature detecting element for detecting the temperature of the detecting element directly or indirectly, and a correcting processor for correcting the signals output from the inertia sensor based on the result detected by the first temperature detecting element and the second temperature detecting element.

Abstract: The angular velocity sensor for detecting an angular velocity for detecting movement amounts and for controlling postures of vehicles, airplanes, cameras, and the like. The angular velocity sensor is provided with a piezoelectric vibrator, a temperature compensation function generating section, a correction coefficient setting section, an oscillation section, a synchronous pulse forming section, and a Coriolis output detection section. If an angular velocity is applied to the piezoelectric vibrator vibrating in a specific direction being driven by the oscillator section, a Coriolis force acts on the piezoelectric vibrator, and a vibration is generated which is perpendicular to the vibration in a specific direction. An electric charge generated by this vibration is detected at the detection electrode of the piezoelectric vibrator.

Abstract: A slope correction signal setting unit is configured to output selectively one of a plurality of direct current signals according to the sensed temperature parameter signal. Levels of the plurality of direct current signals are determined to correspond to the predetermined temperature dependent characteristic of the sensor signal. An analog amplifying circuit is connected to the slope correction signal setting unit and configured to amplify the outputted direct current signal according to the sensed temperature parameter signal. An analog arithmetic circuit is connected to the analog amplifying circuit and configured to carry out a predetermined arithmetic operation based on the amplified direct current signal and the sensor signal.

Abstract: The vibrating sensor includes a cell fixed in a housing, the cell including a support member and a vibrating member connected to the support member, together with a thermal masking element extending between the vibrating member and a wall of the housing.

Abstract: The invention concerns a temperature-compensated accelerator measurement using two vibrating resonators whereof the frequencies (f1, f2) are measured, then used for determining (18, 19) the most probable temperature value (T) based on the sum f1+f2 and on a pre-established correlation (14) between the temperature and the sum f1+f2 and finally based on the determination (20) of the amount f1?f2 of the weighted temperature value, calculating (21) the temperature compensated value of the acceleration (?).

Abstract: A system and method for compensating for gradients in a dual cavity device such as but not limited to an accelerometer. A first source drives a first cavity at least two different modes, at least one mode varying with changes in cavity length. A second source drives a second cavity at least two different modes, at least one mode varying with changes in cavity length. A processor determines changes in cavity length as a function of both modes in both cavities to compensate for non-uniform behavior between the cavities.

Abstract: An apparatus 10 for producing one or more characterizing measurements of a surface 12 in relation to a repeatedly reproducible datum axis A-A, the apparatus 10 comprising a probe 14; a first porous surface 16 located on the probe 14, the first porous surface 16 being in communication with a first source of fluid pressure 18, the first porous surface 16 being located proximate to opposing walls 20 that defines a volume 22, so that a non-contacting fluid pressure gap 24 is formed between the first porous surface 16 and the walls 20, the first porous surface 16 defining the datum axis A-A; at least one second porous surface 26 located on the probe 14, the at least one second porous surface 26 being in communication with a second source of fluid pressure 28, the at least one second porous surface 26 being located in a cooperative relationship with the surface 12 to be measured, so that a non-contacting fluid pressure gap 30 is fanned between the at least one second porous surface 26 and the surface to be measured

Abstract: The invention concerns a temperature-compensated accelerator measurement using two vibrating resonators whereof the frequencies (f1, f2) are measured, then used for determining (18, 19) the most probable temperature value (T) based on the sum f1+f2 and on a pre-established correlation (14) between the temperature and the sum f1+f2 and finally based on the determination (20) of the amount f1−f2 of the weighted temperature value, calculating (21) the temperature compensated value of the acceleration (&ggr;).

Abstract: A portable air pressure decay test apparatus for leak testing of a sealed system includes a hollow housing, an air pump having an inlet and an outlet disposed in the housing, and a controller disposed in the housing and connected to the pump for controlling the operation of the pump. A test head is mounted on the housing for releasably attaching to an attachment point of a sealed system. The test head is in fluid communication with the outlet of the pump. When the test head is attached to the attachment point of the sealed system, the controller operates the pump to provide pressured air to the sealed system and raise the pressure in the sealed system to a predetermined value. After the predetermined value of pressure is reached, the controller stops the pump and monitors the air pressure in the sealed system for a predetermined time interval to measure an air pressure decay rate.

Abstract: An improved vibration type angular velocity sensor suppresses temperature variation of the sensitivity in the atmosphere. When the vibrator 31 is subjected to an angular velocity &OHgr; while it is in a driving vibration, it produces a detecting vibration in a direction perpendicular to the direction of the driving vibration. Angular velocity detection is based on a change in capacitance between a comb-like portion 36 of the vibrator 31 and a detecting electrode 50. A relationship between a degree of detuning &agr;=fd/fs, where fd is the resonance frequency in the driving vibration mode and fs is the resonance frequency in the detecting vibration mode, and a value Qs in the detecting vibration mode is given. The term Qs is a function of the mass of the vibrator, a spring constant of springs supporting the vibrator, and an attenuation coefficient.

Abstract: The acceleration detection sensor comprises a plate in which there are defined a support portion, at least one vibrating element carried by the support portion and sensitive to the movements to which the sensor is subjected, and at least one additional portion connected to the vibrating element and active in detecting acceleration, the sensor including a temperature probe comprising a conductive track which is fixed on at least the additional active portion and which is of resistance that varies as a function of ambient temperature.

Abstract: A micromechanical resonator device is disclosed that utilizes competition between the thermal dependencies of geometrically tailored stresses and Young's modulus to (1) reduce the temperature coefficient (TCf) of the resonance frequencies of the micromechanical resonator device without any additional power consumption; and (2) introduce a zero TCf temperature at which subsequent oven-controlled resonators may be biased. A key feature in this resonator design involves the strategic sizing of the geometries of the resonator and its support structure to harness thermal expansion temperature coefficients that oppose and cancel those of Young's modulus variation. This transforms the original monotonically decreasing resonance frequency versus temperature curve to an S-shaped curve (or a linear one with a much smaller slope), with a smaller overall frequency excursion over a given temperature range, and with points at which the resonance frequency TCf is zero.

Abstract: The acceleration detection sensor comprises a plate in which there are defined a support portion, at least one vibrating element carried by the support portion and sensitive to the movements to which the sensor is subjected, and at least one additional portion connected to the vibrating element and active in detecting acceleration, the sensor including a temperature probe comprising a conductive track which is fixed on at least the additional active portion and which is of resistance that varies as a function of ambient temperature.

Abstract: A tuning-fork type vibration gyro enables to suppress pyroelectric noise caused by temperature change and to obtain sensor output having high signal-to-noise ratio. The tuning-fork type vibration gyro includes a tuning-fork type vibration body having two arms mutually disposed in parallel and a base for commonly supporting one end of the each arm, wherein a longitudinal direction of the two arms is defined as a z-axis and a perpendicular direction thereto is defined as an x-axis; driving electrodes respectively formed on the two arms for generating vibration of the two arms in a direction parallel to the x-axis; detecting electrodes respectively formed on the two arms for detecting electromotive force generated when the tuning-fork type vibration body is rotated around the z-axis; and dummy electrodes formed on the two arms in respective areas different from the driving electrodes and the detecting electrodes.

Abstract: A method for delicately adjusting an orientation of features in completed micro-machined electromechanical sensor (MEMS) devices after initial formation and installation within the device packaging to trim one or more performance parameters of interest, including modulation, bias and other dynamic behaviors of the MEMS devices.

Abstract: Diapason type gyrometers using a micro-mechanical structure of vibrating beams. The gyrometer includes a micro-machined sensitive element with at least two symmetrically positioned excitation beams on each side of and parallel to a sensitive Oy axis of the gyrometer. The two beams are connected at their ends through at least one transverse element fixed in its central part to the sensitive Oy axis, to a frame through an elastic torsion return element acting in opposition to the rotation of the transverse element about the Oy axis. The elastic return elements are sized such that the variation of their resonant natural frequency in torsion with temperature is similar to the variation of the resonant natural frequency in bending of the beams with temperature. Such a device may find particular application in the measurement of the angular velocity of a mobile.

Abstract: A method for measuring motion of a user, which is adapted to apply to output signals proportional to rotation and translational motion of the carrier, respectively from angular rate sensors and acceleration sensors, is more suitable for emerging MEMS angular rate and acceleration sensors. Compared with a conventional IMU, said processing method utilizes a feedforward open-loop signal processing scheme to obtain highly accurate motion measurements by means of signal digitizing, temperature control, sensor error and misalignment calibrations, attitude updating, and damping control loops, and dramatically shrinks said size of mechanical and electronic hardware and power consumption, meanwhile, obtains highly accurate motion measurements.

Abstract: An acceleration sensor module capable of performing sensitivity adjustment in a minimum arrangement without containing an amplifier includes an acceleration sensor and a trimmable resistor which are mounted on a printed wiring board. At least one terminal of the acceleration sensor and at least one terminal of the trimmable resistor are connected to at least one external connection terminal of the printed circuit board through printed wiring.

Abstract: A vibrating gyroscope includes a vibrator and an oscillation circuit for exciting the vibrator. Detecting terminals of the vibrator are connected to ground through load resistances, and are also connected to a differential circuit. A synchronous detection circuit detects a signal output from the differential circuit. A smoothing circuit smoothes a signal output from the synchronous detection circuit. An amplifying circuit amplifies a signal output from the smoothing circuit. Resistance values of the load resistances are adjusted depending on temperature drift gradient of the vibrating gyroscope, such that the temperature drift gradient is minimized.

Abstract: A micromechanical resonator device is disclosed that utilizes competition between the thermal dependencies of geometrically tailored stresses and Young's modulus to (1) reduce the temperature coefficient (TCf) of the resonance frequencies of the micromechanical resonator device without any additional power consumption; and (2) introduce a zero TCf temperature at which subsequent oven-controlled resonators may be biased. A key feature in this resonator design involves the strategic sizing of the geometries of the resonator and its support structure to harness thermal expansion temperature coefficients that oppose and cancel those of Young's modulus variation. This transforms the original monotonically decreasing resonance frequency versus temperature curve to an S-shaped curve (or a linear one with a much smaller slope), with a smaller overall frequency excursion over a given temperature range, and with points at which the resonance frequency TCf is zero.

Abstract: A temperature compensated oscillating accelerometer with force multiplier includes a support substrate; a tuning fork suspended above the substrate; a primary anchor device connected between the tuning fork and substrate; a proof mass having an input axis; a force multiplier interconnected between the proof mass and the tuning fork; and a force multiplier anchor connected to the substrate and disposed at approximately the same area along the input axis as the primary anchor for offsetting the opposing effects of thermal expansion and stiffness in response to variations in temperature.

Abstract: Pressure-compensated transducers and accelerometers, and force-sensing and acceleration-sensing methods are described. In a preferred embodiment, regression techniques are utilized in the context of a vibrating beam force transducer to provide a measure of acceleration which is both temperature-compensated and pressure-compensated.

Abstract: A vehicle fuel system has on-board diagnostics for leak testing with correction for different operating conditions. An electronic control unit (ECU) is arranged to carry out a periodic two stage leak test, when the engine is running. Stage A includes evacuation of the fuel tank, monitoring bleedup and recording the pressure rise dP.sub.-- A over a predetermined period A following increase of pressure to a predetermined value p2. Stage B includes measuring the amount dP.sub.-- B by which the pressure in the tank rises above atmospheric due to vapor generation over a predetermined period B following venting and closure fuel system. The ECU calculates a value X representative of leakage from the difference between dP.sub.-- A and dP.sub.-- B using a scaling factor K. The test duration is adjusted in accordance with measured values of fuel level and ambient temperature to ensure that the measured pressure changes are dependent on leakage over a range of operating conditions.

Abstract: A leak diagnosis apparatus and method for a fuel vapor treatment unit where fuel vapor produced in a fuel tank is collected by adsorbing into an adsorption canister and the fuel vapor collected in the adsorption canister is purged under predetermined engine operating conditions and supplied to an engine. The diagnosis apparatus includes a leak diagnosis device unit for diagnosing the presence of fuel vapor leaks by comparing a drive load of an electric pump for when air is pumped by the electric pump into a system of fuel piping to be leak diagnosed with a set judgement level of drive load threshold. A fuel temperature detection device is provided for detecting the temperature of fuel, wherein a fuel vapor leak is deemed to exist when the comparisons show that the drive load of the electric pump is less than the set judgement level. A judgement level setting device is provided for setting the judgment level based on the detected temperature.

Abstract: A fuel vapor leak detection assembly (10) having a pressure sensor (20) which is adapted to be selectively and operatively positioned within a fuel fill vent hose (22) in a non-on-board refueling vapor recovery system and which detects fuel vapor leaks. The pressure sensor (20) includes a generally rectangular housing portion (44) and a terminal portion (42) which communicatively connects the sensor (20) to a controller. A conventional pressure sensing device (56) is contained within housing portion (44). Sensor (20) further includes two opposed, generally hollow vent line connection ends or portions (46), (48) which connect to vent hose (22). Portions (44), (46), and (48) cooperatively form a generally cylindrical pressure sensing passageway (54) in which pressure sensing device (56) resides, thereby allowing the device (56) to accurately sense and measure the value or amount of fuel vapor pressure traveling through passageway (54).

Abstract: The liquid Leak Detector container must be mounted on the radiator support frame in a level position about eight inches from the radiator in line with the overflow tube. The overflow tube has to be cut to enable the tube ends to be fitted over each nipple of the container and secured by adjustable clamps. The radiator must be filled up with coolant to the top of the radiator filling neck while pinching the overflow tube below the coolant level of the overflow holding tank. The radiator cap is put on tight and the pinched tube released. When the engine is started up the coolant will increase in temperature and expand forcing the coolant to flow through the detector container to the overflow holding tank until the engine has reached operating temperature. The coolant will flow back into the radiator when the engine is not running.The presence of air in the coolant begins to accumulate in the top of the radiator when a leak develops.

Abstract: A method and apparatus for detecting leakage from an evaporative emission space (14, 18) of a vehicle fuel system by utilizing naturally occurring vacuum that can occur under certain favorable conditions after a fuel-consuming engine (12) that powers an automotive vehicle has been turned off. If there is no leakage, vapor pressure in the fuel system will begin to decrease. If it is assumed that the vapor pressure was approximately atmospheric when the engine was turned off, and that no leakage existed, ensuing cooling will create increasing vacuum in headspace of the fuel tank as the temperature drops. In the absence of leakage, a well-defined relationship exists. Measurements of physical parameters (24, 26) characterizing fluid conditions in the fuel tank are taken as cooling proceeds and processed. Results are evaluated to obtain leakage information.

Abstract: A method of leak detection for an evaporative emission control system is provided which determines if a potential leak is present in a portion of the system. The method includes the steps of monitoring an engine shut-off event and subsequently sealing the evaporative emission control system atmospheric vent such that the evaporative emission control system's internal pressure is isolated from external influences, absent a leak. After sealing the system, the internal pressure of the system is monitored for changes which should occur upon the cooling of the evaporative emission control system components. That is, when the components cool, the pressure within the sealed system should decrease. If the internal pressure of the evaporative emissions control system reduces so as to create a vacuum, the methodology assesses that no leaks in the system are present.

Abstract: The present invention is a compensation accelerometer comprising a separable housing, a sensitive element mounted in the housing on an elastic suspension element, an angle sensor, a servo amplifier and a momentum sensor. In the proposed accelerometer, the blade of the sensitive element, the elastic suspension element and the frame for securing the sensitive element in the housing (support frame) are all made from a single block of monocrystalline silicon. In addition, the two halves of the separable housing, between which is situated the support frame for the sensitive element, each take the form of a block and a cup-shaped magnetic circuit for the momentum sensor. The block is formed from silicon monocrystal of the same orientation as the sensitive element block. The coils of the momentum sensor are secured on the blade of the sensitive element via intermediate plates formed from a silicon monocrystal of the same orientation as the sensitive element block.

Abstract: This invention relates to a fault diagnosis system for hydraulic pumps in a work vehicle, which is economical and permits sure identification of one or more trouble-developed ones of the hydraulic pumps.Pressure sensors 61-64 are arranged on pressurized fluid lines 30,40, which extend to a tank T from points immediately out of center bypasses of flow control valves 21,231-234,451-454,26 communicated to hydraulic pumps 1-6. Solenoid-operated directional control valves 51-56 are interposed in input circuits of individual regulators 11-16 so that, upon excitation, a pressure of a pilot pump 7 is introduced into the regulators 11-16. When all the flow control valves are brought into neutral positions thereof and a determination is instructed through a switch 80, one of the solenoid-operated directional control valves is excited by a signal from a processor 70 so that pressurized fluid is delivered at a maximum flow rate from the corresponding hydraulic pump.

Abstract: The disclosed invention is an inexpensive, simple and reusable device to aid in setting the spark plug timing of an internal combustion engine by allowing one person to detect a piston's top dead center. In function, the detector is sealably inserted into a spark plug port and is forcibly expelled by the pressure maximum that occurs at top dead center. The detector's expulsion is accompanied by a "pop" sound similar to when a champagne cork is expelled from its bottle, and which can be remotely perceived by the user.

Abstract: An on-board evaporative emission leak detection system and method that detects leakage from an evaporative emission space of a fuel system of an automotive vehicle. A test includes an initialization, or stabilization, phase during which a differential between pressure in the evaporative emission space and atmospheric pressure is created, and then varied, over time, within a range of differential pressures suitable for performing a leak detection test. A leak size measurement is then obtained using an algorithm.

Abstract: A determination as to whether or not the absolute value PCHK of the deviation between a detection value PTANK of a pressure sensor and its average value PTANKAVE exceeds a predetermined pressure DLEAKCHK is repeated within a predetermined time TINTVAL. The number of times the absolute value PCHK has exceeded the predetermined pressure DLEAKCHK is measured on a failure determination counter C91BNG. When the value of the counter C91BNG exceeds a determination threshold value 91BJVD, it is determined that the pressure sensor fails (time t10).

Abstract: A leak detection method for an on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of a fuel system of an automotive vehicle. During a leak detection test, a vent valve closes, and a purge valve, that selectively communicates the evaporative emission space with the engine intake manifold, opens to cause vacuum to be drawn in the evaporative emission space. A vacuum regulator valve regulates evaporative emission space vacuum to a defined vacuum. Subsequently, the purge valve closes. Loss of vacuum, indicative of leakage, is signaled by a pressure sensor. An algorithm detects a substantially constant rate of vacuum loss and then measures the amount of loss over a defined time interval. That measurement is then compensated for volume of the evaporative emission space and rate of fuel volatilization to arrive at a value forming a basis for making a leakage determination.

Abstract: A module for an on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of an automotive vehicle fuel system, and corresponding method that calibrates a leak detection module pump to set a desired stroke of a moveable wall in the pump of such evaporative emission leak detection system. A pump disposed within interior space of the module has an inlet in communication with the interior space and an outlet that communicates through a flow passage with the evaporative emission space. A vent valve within the interior space is selectively operable to a first state that vents the flow passage to the interior space of the module, thereby venting the evaporative emission space to atmosphere, and to a second state that does not vent the flow passage to the interior space. An electromechanical actuator within the interior space operates the pump and the vent valve by respective magnetically responsive levers.

Abstract: A test fixture to test for possible leakage past a seal between adjacent portions of two test panels. The test panels are supported on a housing in edge-to-edge relation across the open front of a chamber in a housing. The panels are moved toward the open front of the chamber so that the panels seal against the open front. The housing is supported in a cabinet. Liquid is discharged into the cabinet and directed against the seal. The housing has a rear wall which is visible through the cabinet and is constructed to enable viewing into the chamber to see whether the seal has leaked.

Abstract: A module for an on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of an automotive vehicle fuel system. A pump disposed within interior space of the module has an inlet in communication with the interior space and an outlet that communicates through a flow passage by with the evaporative emission space. A vent valve within the interior space is selectively operable to a first state that vents the flow passage to the interior space of the module, thereby venting the evaporative emission space to atmosphere, and to a second state that does not vent the flow passage to the interior space. An electromechanical actuator within the interior space operates the pump and the vent valve by respective magnetically responsive levers. For absorbing impact of a lever with stops, an elastomeric part is disposed on an arm of the lever.

Abstract: A fuel cap leakage tester including a first and a second passage having equal restrictions connected to an inlet which receives a source of pressure. A restriction is placed at the outlet of first passage and the cap to be tested is placed at the outlet of the second passage. An indicator is connected to the first passage between the inlet restriction and outlet restriction and to the second passage between the inlet restriction and the outlet for indicating if the leakage at the outlet with the cap therein is greater or less than the flow rate of the other outlet restriction. The other outlet restriction is set to a desired standard.

Abstract: The leakage inspection for a compressed natural gas (CNG) supply piping system where a filling passage 4 and a supplying passage 5 are provided in a valve body 3 which serves as a block of a CNG fuel container. The filling passage 4 and the supplying passage are provided with a manual stop valves 13 and 7. A solenoid valve 8 is disposed at an open end of the supplying passage 8. A CNG filling inlet 10 is provided at an outer end of a filling conduit 9 communicated to the filling passage 4. A conduit 12 extending to an engine is provided with an inspection gas inlet 14. For the leakage inspection, the stop valves 7 and 13 are closed and an inspection gas is introduced from a leakage inspection gas inlet 14 and the filling inlet 10. It is examined by measuring a pressure change in the conduits 9 and 12 to determine whether or not a leakage problem is occurring.

Abstract: A module for an on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of a fuel system of an automotive vehicle. A housing provides an inlet port, an outlet port, and a flow path between the inlet port and the outlet port. An electric-motor-operated impeller pump causes flow in one direction along the flow path when in a pumping mode of operation. The pump is open to flow in both the one direction and an opposite direction when in a non-pumping mode. A solenoid-operated valve is disposed in the flow path to block flow through the flow path when in a blocking mode and to pass flow through the flow path when in a passing mode. A pressure switch is exposed to the flow path at the outlet port. A lead frame assembly provides respective electric circuit connections to the motor, solenoid, and pressure switch.

Abstract: A method of introducing a leak detection dye into a closed refrigeration system through circulation of the refrigerant. A predetermined amount of the leak detection dye, which is soluble in the refrigerant and the system lubricant, is installed in a component of the refrigeration system, such as in a desiccant bag placed in a dehydrator. The leak detection dye may come in various forms including as a leak detection additive having the leak detection dye implanted on and absorbed into a host swatch of a substrate material, as a powder, as a solid pellet of powdered dye concentrate and inert ingredients, or as a slurry. The refrigeration system is assembled, charged and operated, by which the refrigerant and system lubricant flowing through the component, such as a desiccant bag in the dehydrator, and mixes the dye with the refrigerant and system lubricant.