JP2735678B2 - Flow sensor type flow meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a flow meter in which a flow velocity sensor and a fluidic element are combined.

[Prior Art] A flow meter for measuring a small flow rate region in which a flow rate sensor and a fluidic element are combined with a fluidic element to cause a measurement error or cannot be measured by a flow sensor is disclosed in Japanese Utility Model Application Laid-Open No. 1-58118. I have.

[Problems of the Related Art] The above-mentioned flowmeter uses a fluidic element as a main sensor. However, the fluidic element has difficulty in rectifying the internal flow path shape and the nozzle upstream side, and there is a limit to miniaturization. .

On the other hand, one of the major issues required for flow meters is a demand for miniaturization.

[Means for Solving the Problems] The present invention has been proposed in view of the above points, and has the following configuration.

1.A flow rate sensor and a fluidic element are combined, and the measurement as a flow meter is performed by an arithmetic circuit that measures the flow rate based on the flow rate signal output from the flow rate sensor, and the flow rate signal output from the fluidic element is:
When a predetermined flow rate is output, it is compared with a flow rate signal output from the flow rate sensor, and when the flow rate is within a predetermined error range, the flow rate is directly calculated. A flow rate measurement type flow meter comprising: a flow rate measurement check circuit for performing an arithmetic adjustment for making an error between the flow rate signal output from the Dick element and the error to be zero or close to this.

Although the flow velocity sensor is basically inserted into the nozzle of the fluidic element, it may be located at any other location where the flow velocity can be detected.

Next, although the configuration of the fluidic element is not particularly limited in the present invention, in order to enable easy design and downsizing, a target is arranged in front of the ejection side of the nozzle in the vibration generating chamber, The outlet of the chamber may be configured to have a narrowed shape.

[Operation] The flow rate sensor measures all flow rates as a flow meter, for example, 0 to 3,000 / h, and this flow rate signal is input to an arithmetic circuit, and the arithmetic circuit performs a flow rate calculation based on the flow coefficient.

On the other hand, the fluidic element is designed in advance so that the most accurate flow rate can be measured at a certain flow rate, for example, 250 / h. When the flow signal has an error of, for example, 1.5% or more, the flow rate operation coefficient is updated (calibrated) so as to match the flow signal on the fluidic element side (error is set to 0).

In this way, the output of the flow velocity sensor is constantly checked when the flow rate is 250 / h, and the use as an appropriate flow meter can be continued.

Embodiment FIG. 1 shows an embodiment of the present invention. 1 is a fluidic element, 2 is a nozzle unit, 3 is a flow rate sensor for measuring 0 to 3,000 / h inserted in the nozzle unit 2, and a flow rate signal output from the flow rate sensor 3 is a flow rate calculation circuit. 4 and is calculated based on the flow coefficient by the flow calculation circuit 4, and the integrated value is output to the display circuit 5.

Reference numerals 6 and 6a denote pressure detection ports inserted on both sides of the target 7 of the fluidic element 1, and the pressure detection ports 6, 6a
The differential pressure signal detected in step (1) is input to the fluid vibration detection circuit 8, converted into a flow rate signal, and input to the check circuit 9 in the flow rate calculation circuit 4.

In the case of the embodiment, the fluidic element 1 includes the nozzle 2, the target 7, the pressure detection ports 6, 6a, the aperture 10, and the like.
It is designed to be the best that can accurately measure the flow rate of 250 / h.

The check circuit 9 is 250 m from the fluidic element 1 side.
When the flow rate signal of / h is input, the flow rate signal from the flow velocity sensor 3 is read, and it is assumed that this indicates 258 / h, for example. At this time, it can be determined that the difference between the two is greater than the preset error of 1.5%, so at this time, the flow coefficient in the arithmetic circuit 4 is updated to 250 / h. Adjust so that

When the error is within 1.5%, the flow rate is calculated with the same coefficient.

[Effects of the Present Invention] As described above, the present invention uses the flow rate sensor for measuring the flow rate, and uses the fluidic element as a sensor for detecting the flow rate for checking at a certain flow rate.

As a result, the design of the fluidic element only needs to measure an accurate flow rate at a certain flow rate, so that the design is very easy and the size can be reduced as much as possible.

Therefore, the present invention is effective as a gas meter particularly required to be accurate and downsized.

[Brief description of the drawings]

 The figure is an embodiment diagram of the present invention. DESCRIPTION OF SYMBOLS 1 ... Fluidic element 2 ... Nozzle 3 ... Flow velocity sensor 4 ... Flow rate calculation circuit 5 ... Display circuit 6, 6a ... Pressure detection port 7 ... Target 8 ... Fluid vibration detection circuit 9 ... Check circuit 10 …… Aperture

Claims (3)

(57) [Claims] An arithmetic circuit for measuring a flow rate based on a flow rate signal output from a flow rate sensor for all measurements as a flow meter by combining a flow rate sensor and a fluidic element, and a flow rate signal output from the fluidic element. However, when a predetermined flow rate is output, the flow rate signal output from the flow velocity sensor is compared, and when the flow rate is within a predetermined error range, the flow rate is directly calculated, and when the flow rate is out of the range, the flow rate coefficient is updated. A flow measurement check circuit for performing arithmetic adjustment to make an error between the flow signal output from the fluidic element and the flow signal equal to or close to zero. 2. The flow meter according to claim 1, wherein the flow sensor is inserted into a nozzle of the fluidic element. 3. The flow sensor type as claimed in claim 1, wherein the fluidic element has a structure in which a target is disposed in front of the ejection side of the nozzle in the vibration generation chamber, and the outlet of the vibration generation chamber is narrowed. Flowmeter.