초록 ▼

An apparatus detects an opening in a fluid flow passageway such as occurs when a resistance welding cap which is cooled by the fluid flow becomes accidently detached from a welding machine. Upon detection of an opening, an air-actuated pinch lever is activated to quickly pinch shut flexible fluid in

An apparatus detects an opening in a fluid flow passageway such as occurs when a resistance welding cap which is cooled by the fluid flow becomes accidently detached from a welding machine. Upon detection of an opening, an air-actuated pinch lever is activated to quickly pinch shut flexible fluid inlet and outlet hoses and thereby shut off the fluid flow. Inlet and outlet flow rate sensors provide periodic outputs to a digital computer which determines directions of inlet and outlet flow acceleration. If either the inlet or outlet acceleration changes direction, a baseline inlet or outlet flow rate is set equal to the corresponding current flow rate value to prevent erroneous opening detection due to normal flow fluctuations. If the inlet and outlet accelerations are in the same direction, the baseline values are similarly updated. If the inlet acceleration is positive and the outlet acceleration is negative, it indicates a probable opening. Another test is made to preclude an erroneous detection by determining if the inlet and outlet flow rates are different from the baseline values by more than a predetermined percentage. If so, a valid opening is indicated and the fluid flow is shut off.

대표청구항 ▼

[ What is claimed is:] [1.] An apparatus for detecting an opening in a fluid flow passageway having an inlet and an outlet, comprising:an inlet sensor for sensing an inlet flow rate;an outlet sensor for sensing an outlet flow rate; anda computer which is responsive to the inlet and outlet sensors an

[ What is claimed is:] [1.] An apparatus for detecting an opening in a fluid flow passageway having an inlet and an outlet, comprising:an inlet sensor for sensing an inlet flow rate;an outlet sensor for sensing an outlet flow rate; anda computer which is responsive to the inlet and outlet sensors and is programmed to determine a direction of an inlet flow acceleration and an outlet flow acceleration; determine if a first condition is present in which the inlet flow acceleration and outlet flow acceleration are in different directions; determine if a second condition is present in which the inlet flow rate is different from an inlet baseline value by more than a first predetermined value, and the outlet flow rate is different from an outlet baseline value by more than a second predetermined value; and generate an opening detection indication in response to presence of both the first and second conditions.