US 12,140,135 B2
Fluid control device
Kenjiro Okaguchi, Kyoto (JP); and Nobuhira Tanaka, Kyoto (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Kyoto (JP)
Filed on Feb. 25, 2022, as Appl. No. 17/652,534.
Application 17/652,534 is a division of application No. 16/538,962, filed on Aug. 13, 2019, granted, now 11,293,429.
Application 16/538,962 is a continuation of application No. PCT/JP2018/006672, filed on Feb. 23, 2018.
Claims priority of application No. 2017-034269 (JP), filed on Feb. 27, 2017; application No. 2017-094527 (JP), filed on May 11, 2017; and application No. 2018-013503 (JP), filed on Jan. 30, 2018.
Prior Publication US 2022/0178363 A1, Jun. 9, 2022
Int. Cl. F04B 45/047 (2006.01); F04B 17/00 (2006.01); F04B 43/04 (2006.01); F04B 49/06 (2006.01); F04B 49/10 (2006.01)
CPC F04B 45/047 (2013.01) [F04B 17/003 (2013.01); F04B 43/046 (2013.01); F04B 49/06 (2013.01); F04B 49/103 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A fluid control device comprising:
a piezoelectric pump that includes a pump chamber having a piezoelectric element and a valve chamber communicating with the pump chamber and having a valve, a pump chamber opening which allows the pump chamber to communicate with an outside-pump-chamber space and a valve chamber opening which allows the valve chamber to communicate with an outside-valve-chamber space;
a driving circuit that receives a driving power supply voltage applied thereto and drives the piezoelectric element; and
a drive control circuit that is connected between the driving circuit and an input terminal for the driving power supply voltage and outputs the driving power supply voltage to the driving circuit,
wherein the drive control circuit adjusts the driving power supply voltage or a driving current corresponding to the driving power supply voltage in accordance with a differential pressure between the outside-pump-chamber space and the outside-valve-chamber space or in accordance with a time elapsed from a supply start time of the driving power supply voltage,
wherein the drive control circuit performs control so that the driving power supply voltage or the driving current at a maximum value of the differential pressure becomes lower than the driving power supply voltage or the driving current at a predetermined first differential pressure smaller than the maximum value of the differential pressure, and
wherein the predetermined first differential pressure is an average of a minimum value of the differential pressure and the maximum value of the differential pressure.