JPS602624B2 - Flow rate measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow velocity measuring device for measuring wind velocity and the like.

Conventional flow velocity measurement devices have difficulty measuring average wind velocity over a wide range.

Therefore, when measuring the average wind speed in a duct, the inside of the duct is divided equally in a direction perpendicular to the wind direction, the wind speed at each location is measured, and the average wind speed is calculated from this wind speed value.

For this reason, the process was troublesome and time-consuming, and it also had the disadvantage of lack of reproducibility. This invention was made in view of these points, and includes a conductive elastic member that expands and contracts according to the flow velocity of a fluid, and a measurement method that measures the electrical resistance of this elastic member and outputs an output according to the measured value. It is an object of the present invention to provide a flow rate measuring device that does not have the above-mentioned drawbacks.

Hereinafter, a flow rate measuring device according to an embodiment of the present invention shown in FIGS. 1 to 3 will be described.

In the figure, 1 and 2 are wind tunnels with a rectangular cross section that are spaced apart from each other, and 3 is a square mounting frame inserted between the wind tunnels 1 and 2, which is a hollow part that allows the wind tunnels 1 and 2 to pass through each other. 3a
is formed.

Reference numeral 4 denotes a metal wire which is an expandable member, and both ends thereof are fixed to one end of the mounting frame 3 via fixed terminals 5 .

Four metal wires 4 are arranged parallel to each other at equal intervals so as to divide the hollow portion 3a into five equal parts. The metal wire 4 has a small diameter so that it expands and contracts according to wind resistance, that is, wind speed. Reference numeral 6 denotes a connection conductor that connects the metal wires 4 in series by making the fixed terminals 5 tangent to each other, and 7 is a lead wire that connects the fixed terminals 5 that are the ends of the series electrical circuit formed by the metal wires 4. It is connected to the.

Reference numeral 8 denotes metal wires having both ends fixed to the other end of the mounting frame 3 by fixed terminals 5, and four metal wires 8 are arranged parallel to the metal wires 4 at the same positions as the metal wires 4 in the side direction.

The material of the metal wire 8 is the same as that of the metal wire 4, but its diameter is much larger than that of the metal wire 4 so as not to expand or contract due to wind resistance. In addition, the metal wire 8 has
Although not shown, the connection conductor 6 and the lead wire 7 are connected in the same way as the metal wire 4. Numeral 9 is provided at each end of the mounting frame 3 to prevent the air in the wind tunnels 1 and 2 from leaking. Numeral 10 is a mounting hole, which is provided through the mounting hole 3b, and which connects the mounting frame 3 to the wind tunnels 1 and 2. This is the bolt that secures it.

Reference numerals 11 and 12 refer to a constant current power supply that supplies a constant current to each of the metal wires 4 and 8. Reference numeral 13 refers to a correction device that detects the pressure in accordance with the electrical resistance of the metal wire 8 and outputs a temperature correction signal in accordance with this detected value. The signal derivator 14 is a detector that detects a voltage according to the electrical resistance of the metal wire 4 and corrects this detected value using a temperature correction signal, assuming that the temperature of the metal wire 4 does not change. It is composed of an arithmetic device that outputs an output according to the electrical resistance of the

The constant current power supply 12 and the detector 14 constitute a measuring device 15. Reference numeral 16 denotes a display that converts the output of the detector 14 into wind speed and displays it.

When measuring the average wind speed of wind tunnels 1 and 2, the constant current power supply 11
, 12 to cause a constant current to flow through each of the metal wires 4 and 8.

When a constant current flows through the metal wires 4 and 8, a voltage is generated between the ends of the metal wires 4 and 8 according to their respective electrical resistances, and these voltages are transmitted to the detector 14 and the correction signal derivator 1.
Detected by 3. By the way, the metal wire 4 changes as the wind speed changes, but since the metal wire 8 has a large diameter, its length remains constant even if the wind speed changes.

Further, both the metal wires 4 and 8 expand and contract as the temperature changes. Naturally, the electrical resistance of the metal wires 4 and 8 changes depending on the expansion and contraction of the metal wires 4 and 8, respectively. Therefore, the electrical resistance of the metal wire 4 is determined by the wind speed and temperature in the wind tunnels 1 and 2, and the electrical resistance of the metal wire 8 is determined only by the temperature. From this, it can be understood that the output of the detector 14 can be corrected by the output of the correction signal deriving device 13 to a value corresponding to the electrical resistance of the metal wire 4 assuming that the temperature does not change.

Since a plurality of metal wires 4 and 8 are arranged almost equally within the wind tunnels 1 and 2, the wind speed displayed by the display 16 is the average wind speed within the wind tunnels 1 and 2.

Note that since the cross-sectional area of the honor frame 3 is known, the average air volume can also be measured.

In the above-mentioned embodiment of the present invention, a plurality of metal wires are provided, but if the wind speed distribution in the wind tunnel is known, one metal wire may be provided at any position on the mounting frame. Only the average wind speed can be measured.

Note that the current velocity measuring device of the present invention can measure the average wind velocity not only in a wind tunnel but also in any arbitrary location such as in the atmosphere.

As described above, the flow rate measuring device of the present invention includes a conductive member that is placed in a flow path through which a fluid flows and expands and contracts according to the flow rate of the fluid, and an output that measures the electrical resistance of this member and outputs an output according to the measured value. Since a measuring device for emitting the fluid is provided, it is possible to easily measure the average flow velocity of the fluid.

[Brief explanation of the drawing]

1 to 3 show a flow rate measuring device according to an embodiment of the present invention, FIG. 1 is a side sectional view thereof, FIG. 2 is a plan view thereof, and FIG. 3 is a circuit diagram thereof. In the figure, 1 and 2 are wind tunnels, 3 is a mounting frame, 4 and 8 are metal wires, 1
2 is a constant current power supply, 14 is a detector, 15 is a measuring device, and 16 is a display device. In the figures, the same reference numerals indicate the same or corresponding parts. Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. An elastic member having electrical conductivity that is arranged in a flow path through which a fluid flows and expands and contracts according to the flow rate of the fluid, and measures the electrical resistance of this elastic member and outputs an output according to the measured value. Flow rate measuring device with measuring device. 2. The flow rate measuring device according to claim 1, wherein the expandable member is formed of a metal wire. 3. According to claim 1 or 2, the measuring device is comprised of a constant current power source that flows a constant current through the elastic member and a detector that detects a potential difference between both ends of the upper elastic member. flow rate measuring device.