The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 13, 2001
Filed:
Apr. 24, 2000
Tadahiro Ohmi, Miyagi 980-0813, JP;
Satoshi Kagatsume, Yamanashi, JP;
Jun Hirose, Yamanashi, JP;
Kouji Nishino, Osaka, JP;
Other;
Abstract
A fluid-switchable flow rate control system that permits free changing of the full scale flow rate and which can control a plurality of kinds of fluids with high precision. The fluid-switchable flow rate control system controls the flow rate of fluid with the pressure P,on the upstream side of the orifice member held about twice or more higher than the downstream pressure P,, the fluid-switchable flow rate control system comprising an orifice member,replaceable with another to provide a suitable orifice diameter according to the kind of fluid and the flow rate range, a control valve,provided on the upstream side thereof, a pressure detector,provided between the control valve,and the orifice member,, a flow rate calculation circuit,where from the pressure P,detected by the pressure detector, the flow rate Qc is calculated with the equation Qc=KP,(K=constant), a flow rate-setting circuit,for outputting flow rate setting signal Qe, a flow rate conversion circuit,for multiplying the calculated flow rate signal Qc by the flow rate conversion rate k into switch-over calculated flow rate signal Qf (Qf=kQc) to change the full scale flow rate, and a calculation control circuit,to output the difference between the switch-over calculation flow rate signal Qf and the flow rate setting signal Qe as control signal Qy to the drive,of the control valve,, thereby opening or closing the control valve to bring the control signal Qy to zero, thus controlling the flow rate on the downstream side of the orifice member.