Vacuum-based leak detection
AssigneeRobert Bosch GmbH
InventorsWilliam Brown, Chad Samp
Life of this patent
Estimating the term…
Abstract
A system and method for detecting leaks in an enclosure having a port and intended to prevent liquid material from exchanging into or out of the enclosure. A vacuum pump is coupled to the port and the enclosure is subjected to an applied vacuum pressure. Measurements of the mass and pressure within the enclosure while subject to the applied vacuum pressure are compared to expected values to detect a leak. In some embodiments, the physical arrangement of a valve of the enclosure is measured and compared to expected values to detect a leak.
Claims18
A method of leak detection for an automotive battery enclosure having a seal, an internal chamber, and a plurality of ports in fluid communication with the internal chamber including a first port with a valve, wherein the method comprises:
- applying a vacuum pump having a mass airflow sensor to a first port;
- sealing the other ports of the plurality of ports;
- activating the vacuum pump to apply a predetermined fixed vacuum pressure to the internal chamber;
- generating, with the mass airflow sensor, mass exchange rate data indicating a rate of mass exchange within the enclosure;
- generating, with the mass airflow sensor, mass exchange rate data indicating a rate of data indicating a pressure within the internal chamber;
- measuring the displacement of the valve while the vacuum pump is activated;
- and
- outputting a leak indication signal indicating that at least one leak in the seal is present when the mass exchange rate data indicates that the rate of mass exchange is greater than an expected threshold rate value or when the measured displacement of the valve deviates from an expected displacement value by an amount greater than an expected threshold displacement value,
- wherein
- the seal of the enclosure is suitable to prevent an exchange of liquid material and permit an exchange of gaseous material.
A method of leak detection for an automotive battery enclosure having a seal, an internal chamber, and a plurality of ports including a first port with a valve, the first port being in fluid communication with the internal chamber, wherein the method comprises:
- applying a vacuum pump having a mass airflow sensor to the first port;
- sealing the other ports of the plurality of ports;
- activating the vacuum pump to apply a predetermined fixed vacuum pressure to the internal chamber;
- generating, with the mass airflow sensor while the vacuum pump is activated, pressure data indicating a pressure within the internal chamber;
- measuring the displacement of the valve while the vacuum pump is activated;
- outputting a leak indication signal indicating that at least one leak in the seal is present when the measured displacement of the valve deviates from an expected displacement value by an amount greater than an expected threshold displacement value,
- wherein
- the seal of the enclosure is suitable to prevent an exchange of liquid material and permit an exchange of gaseous material.
A method of leak detection for an automotive battery enclosure having a seal, an internal chamber, and a plurality of ports including a first port with a valve, the plurality of ports being in fluid communication with the internal chamber, wherein the method comprises:
- applying a vacuum pump having a mass airflow sensor to the first port;
- sealing the other ports of the plurality of ports;
- activating the vacuum pump to apply a predetermined fixed vacuum pressure to the internal chamber;
- generating, with the mass airflow sensor while the vacuum pump is activated, pressure data indicating a pressure within the internal chamber;
- generating, with the mass airflow sensor while the vacuum pump is activated, mass exchange rate data indicating a rate of mass exchange within the enclosure;
- increasing the pressure applied by the vacuum pump after activation until the mass airflow sensor indicates a predetermined pressure value;
- measuring a time datum indicating how long from the activation of the vacuum pump it takes for the internal chamber to reach the predetermined pressure value;
- measuring the displacement of the valve while the vacuum pump is activated;
- measuring the applied pressure of the vacuum pump when the mass airflow sensor indicates the predetermined pressure value;
- and
- outputting a leak indication signal indicating at least one leak in the seal is present when the time datum is greater than an expected threshold time value, the applied pressure of the vacuum pump is greater than an expected threshold pump pressure value, when the mass exchange rate data indicates that the rate of mass exchange is greater than an expected threshold rate value, or the measured displacement of the valve deviates from an expected displacement value by an amount greater than an expected threshold displacement value.
Dependencies are inferred from the claim text.