Leakage sensor apparatus for fluid passageway
First Claim
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1. An apparatus for measuring a degree of leakage from a fluid passageway, comprising:
- pressure sensor means connected to the passageway for producing an electric sensor signal corresponding to fluid pressure in the passageway;
pressure source means for applying fluid pressure of at least an upper predetermined value to the passageway;
valve means for disconnecting the source from the passageway when the pressure in the passageway is at least equal to the upper predetermined value;
comparator means responsive to the sensor means for comparing the sensor signal with first and second reference signals corresponding to the upper predetermined value of pressure and a lower predetermined value of pressure and producing first and second output signals respectively in response to coincidence thereof; and
timer means for measuring a length of time between generation of the first and second output signals by the comparator means.
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Abstract
A fluid pressure passageway (14) such as a high pressure fuel line in a fuel injection system is pressurized to an upper predetermined value. Then, the passageway (14) is isolated and the length of time for the pressure to drop to a lower predetermined value is measured. The greater the degree of leakage, the shorter the measured length of time. An alarm (24) is energized when the measured length of time is shorter than a predetermined length of time.
43 Citations
12 Claims
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1. An apparatus for measuring a degree of leakage from a fluid passageway, comprising:
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pressure sensor means connected to the passageway for producing an electric sensor signal corresponding to fluid pressure in the passageway; pressure source means for applying fluid pressure of at least an upper predetermined value to the passageway; valve means for disconnecting the source from the passageway when the pressure in the passageway is at least equal to the upper predetermined value; comparator means responsive to the sensor means for comparing the sensor signal with first and second reference signals corresponding to the upper predetermined value of pressure and a lower predetermined value of pressure and producing first and second output signals respectively in response to coincidence thereof; and timer means for measuring a length of time between generation of the first and second output signals by the comparator means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for measuring a degree of leakage from a fluid passageway, comprising:
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pressure sensor means connected to the passageway for producing an electric sensor signal corresponding to fluid pressure in the passageway; pressure source means for applying fluid pressure of at least an upper predetermined value to the passageway; valve means for disconnecting the source from the passageway when the pressure in the passageway is at least equal to the upper predetermined value; comparator means responsive to the sensor means for comparing the sensor signal with first and second reference signal corresponding to the upper predetermined value of pressure and a lower predetermined value of pressure and producing first and second output signals respectively in response to coincidence thereof; and timer means for measuring a length of time between generation of the first and second output signals by the comparator means; the timer means comprising a down counter, means for setting a predetermined number into the counter in response to the first output signal, clock pulse generator means for generating clock pulses, gate means connected between the clock pulse generator means and a clock input of the counter and means responsive to the first and second output signals for enabling the gate means only for the length of time between generation of the first and second output signals. - View Dependent Claims (11)
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12. An apparatus for measuring a degree of leakage from a fluid passageway, comprising:
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pressure sensor means connected to the passageway for producing an electric sensor signal corresponding to fluid pressure in the passageway; pressure source means for applying fluid pressure of at least an upper predetermined value to the passageway; valve means for disconnecting the source from the passageway when the pressure in the passageway is at least equal to the upper predetermined value; comparator means responsive to the sensor means for comparing the sensor signal with first and second reference signals corresponding to the upper predetermined value of pressure and a lower predetermined value of pressure and producing first and second output signals respectively in response to coincidence thereof; and timer means for measuring a length of time between generation of the first and second output signals by the comparator means; the sensor means comprising a sensor for producing an electric current corresponding to fluid pressure in the passageway and a current to voltage converter for converting the electric current into an electric voltage; the sensor means further comprising an analog to digital converter for converting the electric voltage into a digital signal, the digital signal constituting the sensor signal.
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Specification