Automotive evaporative emission leak detection system
    1.
    发明授权
    Automotive evaporative emission leak detection system 失效
    汽车蒸发排放物泄漏检测系统

    公开(公告)号:US06283097B1

    公开(公告)日:2001-09-04

    申请号:US08918065

    申请日:1997-08-25

    IPC分类号: F02M3704

    CPC分类号: F02M25/0818

    摘要: A leak detection system for detecting leakage from a portion of a vapor confinement space which is upstream of an inlet of a canister purge valve relative to an engine. During a test, an electric-motor-operated air pump pumps atmospheric air through a flowpath providing communication between the pump and the vapor confinement space. A flowmeter has a thermistor in the flowpath. The thermistor has a predetermined temperature vs. electric current characteristic that enables it to provide a signal correlated to flow of air through the flowpath. An electric circuit supplies and measures the electric current drawn by the thermistor to create a signal representative of the pumped airflow. The test is conducted in accordance with an algorithm that pre-heats the thermistor to a stable state before the pump is turned on. The pump is then turned on to create a predefined superatmospheric target pressure in the vapor confinement space. Once the target pressure is reached, the airflow measured by the flowmeter provides a leakage measurement. The pump is then shut off and the vapor space vented to atmosphere through the flowmeter and pump. The thermistor current draw is once again measured to detect any drift in its characteristic.

    摘要翻译: 一种泄漏检测系统,用于检测来自罐排放阀的入口相对于发动机的上游的蒸汽限制空间的一部分的泄漏。 在测试期间,电动机操作的空气泵通过提供泵和蒸汽限制空间之间的连通的流动路径泵送大气。 流量计在流路中具有热敏电阻。 热敏电阻具有预定的温度对电流特性,使其能够提供与通过流路的空气流相关的信号。 电路提供并测量由热敏电阻吸引的电流,以产生代表泵送气流的信号。 该测试根据在泵打开之前将热敏电阻预热到稳定状态的算法进行。 然后将泵打开以在蒸汽限制空间中产生预定的超大气压目标压力。 一旦达到目标压力,流量计测量的气流就会提供泄漏测量。 然后关闭泵,蒸汽空间通过流量计和泵排放到大气中。 再次测量热敏电阻电流消耗以检测其特性中的任何漂移。

    Automotive evaporative emission leak detection system and method
    2.
    发明授权
    Automotive evaporative emission leak detection system and method 失效
    汽车蒸发排放物泄漏检测系统及方法

    公开(公告)号:US6016690A

    公开(公告)日:2000-01-25

    申请号:US36128

    申请日:1998-03-06

    IPC分类号: G01M3/02 G01M3/32

    CPC分类号: G01M3/025

    摘要: 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.

    摘要翻译: 一种用于检测来自机动车辆的燃料系统的蒸发排放空间的泄漏的车载蒸发排放泄漏检测系统的泄漏检测方法。 在泄漏检测测试期间,排气阀关闭,并且将选择性地将蒸发发射空间与发动机进气歧管连通的排气阀打开,从而在蒸发发射空间内吸引真空。 真空调节阀将蒸发发射空间真空调节至确定的真空。 随后,清洗阀关闭。 通过压力传感器发出指示泄漏的真空损失。 算法检测基本上恒定的真空度损失率,然后在规定的时间间隔内测量损失量。 然后,该测量值补偿蒸发发射空间的体积和燃料挥发速率,以达到形成泄漏确定基础的值。

    Temperature correction method and subsystem for automotive evaporative leak detection systems
    4.
    发明授权
    Temperature correction method and subsystem for automotive evaporative leak detection systems 有权
    汽车蒸发泄漏检测系统的温度校正方法和子系统

    公开(公告)号:US07194893B2

    公开(公告)日:2007-03-27

    申请号:US09165772

    申请日:1998-10-02

    IPC分类号: G01M3/34

    CPC分类号: F02M25/0818 F02M25/0809

    摘要: A method and sensor or sensor subsystem permit improved evaporative leak detection in an automotive fuel system. The sensor or sensor subsystem computes temperature-compensated pressure values, thereby eliminating or reducing false positive or other adverse results triggered by temperature changes in the fuel tank. The temperature-compensated pressure measurement is then available for drawing an inference regarding the existence of a leak with reduced or eliminated false detection arising as a result of temperature fluctuations.

    摘要翻译: 一种方法和传感器或传感器子系统允许在汽车燃料系统中改进蒸发泄漏检测。 传感器或传感器子系统计算温度补偿压力值,从而消除或减少由燃料箱温度变化触发的假阳性或其他不利结果。 然后,温度补偿压力测量可用于绘制关于由于温度波动引起的减少或消除的错误检测的泄漏的存在的推断。

    Method of managing pressure in a fuel system
    5.
    发明授权
    Method of managing pressure in a fuel system 失效
    管理燃油系统压力的方法

    公开(公告)号:US06983641B1

    公开(公告)日:2006-01-10

    申请号:US09565028

    申请日:2000-05-05

    IPC分类号: G01M3/02

    摘要: An integrated pressure management system manages pressure and detects leaks in a fuel system. The integrated pressure management system also performs a leak diagnostic for the headspace in a fuel tank, a canister that collects volatile fuel vapors from the headspace, a purge valve, and all associated hoses and connections.

    摘要翻译: 集成的压力管理系统管理压力并检测燃料系统中的泄漏。 集成压力管理系统还对燃料箱中的顶部空间进行泄漏诊断,从顶部空间收集挥发性燃料蒸气的罐,净化阀以及所有相关联的软管和连接。

    Temperature correction method and subsystem for automotive evaporative leak detection systems
    7.
    发明授权
    Temperature correction method and subsystem for automotive evaporative leak detection systems 有权
    汽车蒸发泄漏检测系统的温度校正方法和子系统

    公开(公告)号:US06672138B2

    公开(公告)日:2004-01-06

    申请号:US10024280

    申请日:2001-12-21

    IPC分类号: G01M308

    CPC分类号: F02M25/0818 F02M25/0809

    摘要: A method and sensor or sensor subsystem permit improved evaporative leak detection in an automotive fuel system. The sensor or sensor subsystem computes temperature-compensated pressure values, thereby eliminating or reducing false positive or other adverse results triggered by temperature changes in the fuel tank. The temperature-compensated pressure measurement is then available for drawing an inference regarding the existence of a leak with reduced or eliminated false detection arising as a result of temperature fluctuations.

    摘要翻译: 一种方法和传感器或传感器子系统允许在汽车燃料系统中改进蒸发泄漏检测。 传感器或传感器子系统计算温度补偿压力值,从而消除或减少由燃料箱温度变化触发的假阳性或其他不利结果。 然后,温度补偿压力测量可用于绘制关于由于温度波动引起的减少或消除的错误检测的泄漏的存在的推断。

    Pulse interval leak detection system
    8.
    发明授权
    Pulse interval leak detection system 失效
    脉冲间隔泄漏检测系统

    公开(公告)号:US5957115A

    公开(公告)日:1999-09-28

    申请号:US798819

    申请日:1997-02-12

    IPC分类号: F02M25/08 F02M37/04

    CPC分类号: F02M25/0809

    摘要: A system and method for an engine-powered automotive vehicle evaporative emission control system having an evaporative emission space for containing volatile fuel vapors, and a leak detection system for detecting leakage from the evaporative emission space. At the beginning of a test, an initial test pressure that differs sufficiently from atmospheric pressure to allow a leak to be detected is created in the evaporative emission space. After attainment of the initial test pressure in the evaporative emission space, the initial test pressure is restored whenever the pressure changes by a predetermined amount due to a leak. The test includes measuring at least one of: a time interval required for pressure in the evaporative emission space to change from the initial test pressure by the predetermined amount; and b) a time interval required to restore the initial test pressure in the evaporative emission space.

    摘要翻译: 一种用于具有用于容纳挥发性燃料蒸气的蒸发发射空间的发动机动力汽车蒸发排放控制系统的系统和方法,以及用于检测来自蒸发发射空间的泄漏的泄漏检测系统。 在测试开始时,在蒸发发射空间中产生初始测试压力,该初始测试压力与大气压力充分差异以允许检测泄漏。 在达到蒸发发射空间中的初始测试压力之后,只要压力由于泄漏而改变预定量就恢复初始测试压力。 该测试包括测量以下中的至少一个:蒸发发射空间中的压力所需的时间间隔从初始测试压力改变预定量; 和b)恢复蒸发发射空间中的初始测试压力所需的时间间隔。

    Canister vent valve having electric pressure sensor and valve actuator
    9.
    发明授权
    Canister vent valve having electric pressure sensor and valve actuator 失效
    罐式排气阀具有电压传感器和阀门执行器

    公开(公告)号:US5803056A

    公开(公告)日:1998-09-08

    申请号:US798818

    申请日:1997-02-12

    IPC分类号: F02B23/10 F02M25/08 F02M37/04

    摘要: A vapor collection canister vent valve contains both an electric pressure sensor for measuring evaporative emission space pressure during a diagnostic test and an electric actuator for operating the vent valve closed during a diagnostic test. Use of the valve in an evaporative emission control system reduces the number of connections, both electrical and fluid, that are required to install the valve in a system. The remote location of the pressure sensor damps the effect of pressure transients, such as those due to tank fuel slosh, on the sensor.

    摘要翻译: 蒸气收集罐排气阀包含用于在诊断测试期间测量蒸发排放空间压力的电压传感器和用于在诊断测试期间关闭排气阀的电致动器。 在蒸发排放控制系统中使用阀门减少了将阀安装在系统中所需的电气和液体的连接数量。 压力传感器的偏远位置可以抑制压力瞬变的影响,例如由于油箱燃油而产生的压力瞬变对传感器的影响。

    Fuel vapor leak detection system
    10.
    发明授权
    Fuel vapor leak detection system 失效
    燃油蒸汽泄漏检测系统

    公开(公告)号:US5390645A

    公开(公告)日:1995-02-21

    申请号:US205983

    申请日:1994-03-04

    CPC分类号: F02M25/0818

    摘要: Leakage from a portion of a canister purge system which includes a fuel tank and a vapor collection canister is detected by closing off that portion and then positively pressurizing it by means of an air pump. The air that is pumped by the air pump is split into two separate paths, one to pressurize the closed-off portion of the system, and the other to flow through a known orifice. A differential flow meter compares the flow through one path with that through the other to determine if there is leakage.

    摘要翻译: 通过关闭该部分然后通过空气泵对其进行正面加压来检测包括燃料箱和蒸气收集罐的一部分罐式清洗系统的泄漏。 由空气泵泵送的空气被分成两个独立的路径,一个用于对系统的关闭部分加压,另一个流经已知孔。 差分流量计将通过一条通道的流量与另一条流量进行比较,以确定是否存在泄漏。