JPH067019U - Fluidic flow meter - Google Patents

Abstract

(57) [Summary] [Purpose] I would like to obtain a high-precision fluidic flowmeter that can be manufactured at low cost. [Structure] A condenser bidirectional microphone 7 is used as a fluid vibration detection sensor 6. [Effect] The inexpensive condenser bidirectional microphone 7 can detect fluid vibration with high sensitivity. Therefore, it is possible to improve the performance of the fluidic flow meter and reduce the manufacturing cost.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fluidic flow meter used for measuring the flow rate of fluid such as gas.

[0002]

[Prior art]

 A fluidic flow meter is one that converts the fluid vibration generated by the fluidic element into an electrical signal using a piezoelectric membrane sensor, and uses this electrical signal as an input to calculate and measure the flow rate by a computing unit (for example, Japanese Utility Model Application Laid-Open No. 57-66313) and a method of converting fluid vibration into an electric signal by a condenser type microphone to calculate a flow rate (Japanese Utility Model Application Laid-Open No. 57-92121) are known.

[0003]

[Problems to be solved by the device]

 The former piezoelectric film sensor type is currently put into practical use as a gas meter, but since the piezoelectric film is expensive to manufacture and high technology is required to assemble the piezoelectric film as a sensor, the flow meter itself There is a problem that the price will increase. On the other hand, since the latter microphone type has directivity in the microphone itself, if it is used as it is due to this directivity, in-phase vibration generated due to factors such as pipe noise and pressure fluctuation will be detected. However, it has the drawback of causing measurement errors and has not yet been put to practical use.

An object of the present invention is to improve the accuracy of a fluidic flowmeter that detects fluid vibration (converts into an electric signal) with a microphone.

[0005]

[Means for Solving the Problems]

 The structure of the fluidic flow meter according to the present invention is as follows.

A fluidic flow meter configured to detect a fluid vibration generated by a fluidic element by a bidirectional microphone to calculate a flow rate.

[0007]

[Action]

 The fluid ejected from the fluidic element nozzle alternately adheres to the left and right adhering walls due to the Coanda effect, causing fluid vibration. This fluid vibration is guided to a bidirectional microphone as a fluid vibration detection sensor using a conduit or the like, and is introduced before and after the diaphragm. As a result, the diaphragm vibrates, and this vibration outputs an electric signal. The flow rate calculator calculates the flow rate based on the electric signal from the bidirectional microphone, and the calculated value can be displayed on the display circuit or integrated and the integrated value can be read and read at any time. Or

[0008]

【Example】

 In FIG. 1, 1 is a fluidic element, 2 is a nozzle, 3 and 3a are pressure detection holes, and the fluid ejected from the nozzle 2 is alternately adhered to the adhering walls 4, 4a by the Coanda effect. Fluid vibration can be detected from the pressure detection holes 3 and 3a. The detected fluid vibration is introduced into the fluid vibration detection sensor 6 incorporating the condenser type bidirectional microphone 7 via the conduits 5 and 5a, and the diaphragm of the microphone 7 (not shown). Acts as pressure before and after. As a result, the diaphragm vibrates in synchronism with the fluid vibration, causing a change in the capacitance between the counter electrodes, and this change can be extracted as an electric signal. The extracted electric signal is input to the flow rate calculation circuit 8 to calculate the flow rate, and the calculated value is displayed on the display circuit 9.

[0009]

[Effect of device]

 As described above, the present invention uses the bidirectional microphone as the fluid vibration detection sensor, and thus has the following effects.

A. The bidirectional microphone as a fluid vibration detection sensor is cheaper than the piezoelectric membrane sensor and has less assembly problems, so the manufacturing cost of the fluidic flowmeter can be reduced.

B. By using a bidirectional microphone, it does not work with vibrations in the same phase generated by noise in the pipe or pressure fluctuations, but can detect only fluid vibrations entering in the opposite phase, so it is a highly sensitive and high-performance fluidic flow meter. Can be obtained.

C. Since it is more resistant to acoustic and vibration noise than a piezoelectric film sensor, accuracy is improved.

[Brief description of drawings]

FIG. 1 is an explanatory view of a fluidic flow meter embodying the present invention.

[Explanation of symbols] 1 Fluidic element 2 Nozzle 3, 3a Fluid vibration detection hole 4, 4a Adhesion wall 5, 5a Conduit 6 Fluid vibration detection sensor 7 Condenser type bidirectional microphone 8 Flow rate calculation circuit 9 Display circuit

Claims (2)

[Scope of utility model registration request] 1. A fluidic flow meter configured to calculate a flow rate by detecting fluid vibration generated by a fluidic element with a bidirectional microphone. 2. The fluidic flowmeter according to claim 1, wherein the fluidic flowmeter is a condenser type bidirectional microphone.