Flow rate sensor
First Claim
1. A flow rate sensor comprising a chamber with first and second diaphragms arranged therein, in an opposed relation to each other,wherein said chamber is divided into a primary chamber facing said first diaphragm and a secondary chamber facing said second diaphragm, wherein a fluid is passed from said primary chamber to said secondary chamber through a bypass having an orifice member thereby to generate a differential pressure between said primary chamber and said secondary chamber, wherein the load difference generated by the fluid pressure fluctuations received by said first diaphragm and said second diaphragm is detected as a displacement by a load difference sensor arranged between said first diaphragm and said second diaphragm thereby to detect the flow rate of said fluid, and wherein a selected one of said diaphragm pair and said load difference sensor includes at least a displacement limiting member for preventing the displacement generated by the fluid pressure fluctuations received by said diaphragms from increasing beyond a predetermined amount.
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Accused Products
Abstract
A flow rate sensor high in pressure resistance has a structure to facilitate the measurement of a minuscule differential pressure for measurement of a very small flow rate. A chamber (20) is defined into a primary chamber (21) and a secondary chamber (25) by two diaphragms (31, 32) arranged in an opposed relation to each other. A fluid is passed from the primary chamber to the secondary chamber through a bypass (35) having an orifice portion (40) thereby to generate a differential pressure. The load generated by the fluid pressure fluctuations received by the first and second diaphragms is detected as a difference of displacement by a load difference sensor (50) arranged between the first and second diaphragms thereby to detect the flow rate of the fluid. Displacement limiting members (61, 62) are provided for the diaphragms or the load difference sensor so that the displacement due to the fluid pressure fluctuations received by the first and second diaphragms may not exceed a predetermined amount.
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Citations
7 Claims
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1. A flow rate sensor comprising a chamber with first and second diaphragms arranged therein, in an opposed relation to each other,
wherein said chamber is divided into a primary chamber facing said first diaphragm and a secondary chamber facing said second diaphragm, wherein a fluid is passed from said primary chamber to said secondary chamber through a bypass having an orifice member thereby to generate a differential pressure between said primary chamber and said secondary chamber, wherein the load difference generated by the fluid pressure fluctuations received by said first diaphragm and said second diaphragm is detected as a displacement by a load difference sensor arranged between said first diaphragm and said second diaphragm thereby to detect the flow rate of said fluid, and wherein a selected one of said diaphragm pair and said load difference sensor includes at least a displacement limiting member for preventing the displacement generated by the fluid pressure fluctuations received by said diaphragms from increasing beyond a predetermined amount.
Specification