Smc Kabushiki Kaisha

Shogo Kurisaki

Kuniko Suzuki

Masao Kataoka

Tomonobu Endou

Takashi Takebayashi

Atsushi Asai

Pinghou Ge

Koichi Katsumata

Ge Pinghou

A rectifying module is arranged on an upstream side of a flow passage containing a flow velocity sensor. The rectifying module includes mesh members each having a plurality of circular small holes and ring-shaped spacers, wherein the mesh members and the spacers are alternately stacked in an axial direction and integrally joined to one another by means of thermal diffusion bonding. The mesh members have identical structures, in which the plurality of small holes are arranged concentrically at angles of separation of 60 degrees in the circumferential direction about the center of a reference small hole. The small holes are formed over the entire surface of the mesh member continuous with adjoining other small holes. The small holes of one mesh member and another mesh member adjacent thereto in the axial direction are arranged so as to have a phase angle difference of 90 degrees in the circumferential direction.

Flow meter with a rectifying module having a plurality of mesh members

Flow amount detector

A threshold value is stored in a CPU using setting switches. When a fluid is introduced into a flow passage, a rod disposed in the flow passage sheds Karman vortexes downstream thereof in the fluid as it flows through the flow passage. A piezoelectric device generates an electric signal depending on pressure fluctuations of the Karman vortexes, and the electric signal is applied through a comparator to the CPU. The CPU refers to a data table stored in a memory to determine a flow rate of the fluid based on the period of the electric signal. When the determined flow rate is greater than the threshold value, the CPU turns on transistors to energize loads as external devices. When the determined flow rate is smaller than the threshold value, the CPU turns off transistors to de-energize loads.

Flow rate detector

A threshold value is stored in a CPU using setting switches. When a fluid is introduced into a flow passage, it lowers the temperature of a first thermistor heated by a regulated constant-current source, increasing the output voltage of the first thermistor. A second thermistor outputs a voltage corresponding to the temperature of the fluid. A differential amplifier outputs a differential voltage between the output voltages of the first and second thermistors, and the differential voltage is converted by an A/D converter into a digital voltage that is applied to a CPU. The CPU refers to a data table stored in a memory to determine a flow rate of the fluid based on the digital differential voltage. When the determined flow rate is greater than the threshold value, the CPU turns on transistors to energize loads as external devices. When the determined flow rate is smaller than the threshold value, the CPU turns off transistors to de-energize loads.

A pressure detector includes a pressure introducer formed in a pipe with a through-hole defined therein and connected to a pressure sensor at one end. A tube fitting is mounted in advance to a fluid passage to which the pressure detector is connected. The other end of the pressure introducer of the pressure detector is inserted axially into an opening of the tube fitting. Thus, the pressure detector is easily connected to the fluid passage without requiring rotating of the pressure detector about the axis of the pressure introducer.

Growing community of inventors

Ibaraki-ken, Japan

Shogo Kurisaki