JPH062109Y2 - Detector for ultrasonic flowmeter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to, for example, a detector for an ultrasonic flow meter that measures the flow rate of gas flowing in a pipeline using ultrasonic waves, and in particular, the flow rate value of the gas to be measured. The present invention relates to compounding a pressure sensor for pressure calibration.

[Prior Art] For example, FIG. 4 is a layout view of a conventional detector for an ultrasonic flow meter, in which 1 is for an ultrasonic flow meter that includes a piezoelectric vibrator and transmits and receives ultrasonic waves. A detector, 20 is a pipeline through which the gas to be measured flows, and 21 is an ultrasonic flowmeter detector 1
Is attached to the pipe 20. 22 is a pressure sensor for measuring the pressure of gas in the pipe 20. 23 is a pressure sensor seat for attaching the pressure sensor 22 to the pipe 20. 24 is a cable.
25 is a terminal box, and the arrow shows the direction of gas flow.

The conventional ultrasonic flowmeter detector is configured as described above,
In measuring the flow rate of the gas in the pipe 20, the crossing angle θ with the pipe 20 is set to about 60 °, and the mounting seats 21 are arranged on both sides of the pipe 20 in a plane including the pipe axis. A pair of ultrasonic flowmeter detectors 1 is attached. The ultrasonic flowmeter detector 1 transmits ultrasonic waves into the gas, and the ultrasonic waves propagated in the gas are received by the corresponding ultrasonic flowmeter detector 1 . The operations of the wave transmission and the wave reception are alternately switched periodically. However, when measuring the flow rate, the gas exhibits various properties depending on its state, and therefore, when evaluating the measured amount, the measured amount is calibrated to a unified standard state.

That is, at the same time as the flow rate measurement, the temperature and pressure of the gas in the pipeline 20 are simultaneously measured in order to obtain the physical properties such as the density, thermal expansion coefficient, and compression coefficient of the gas in the pipeline 20 that are related to the flow rate measurement.

In particular, the pressure of the gas in the pipe 20 may fluctuate due to pressurization, pulsation and sometimes sudden attack, so that the measured quantity is calibrated by the pressure of the gas. Since the ultrasonic flowmeter detector 1 and the pressure sensor 22 are different in the time response of the fluctuation value depending on the arrangement in the pipe 20, the ultrasonic flowmeter detector 1 is close to the installation position in the pipe 20. Then, the pressure sensor seat 23 is provided, and the pressure sensor 22 and the cable 24 are attached to supply power and transmit signals.

[Problems to be Solved by the Invention] In the ultrasonic flowmeter detector 1 as described above, a pair of ultrasonic flowmeter detectors 1 are mounted on the mounting seats 21 that are arranged to face each other with respect to the conduit 20. In order to evaluate the measured quantity obtained by measuring the gas flow rate in various states of temperature and pressure, calibration to the measured quantity in the standard state is performed. Therefore, a pressure sensor seat 23 is provided in the pipe line 20 in the vicinity of the installation position of the ultrasonic flowmeter detector 1 , and a cable 24 for supplying power and transmitting a signal is installed in the pressure sensor 22. I won't.

Further, due to the difference in the installation positions of the ultrasonic flowmeter detector 1 and the pressure sensor 22, the flow rate signal and the pressure signal differ in time response due to pulsation of gas and sudden pressure fluctuations, and the measured amount of There is a problem that the calibration in the standard state cannot be performed accurately.

The present invention has been made in order to solve such a problem, and in the calibration of the measured amount of gas as the measurement fluid in the standard state, the pressure sensor seat 23 for mounting the pressure sensor 22 on the conduit 20 is provided. It is an object of the present invention to obtain a detector for an ultrasonic flowmeter that allows a measured flow rate signal and a pressure signal to simultaneously respond to various states of gas without installing or laying a cable 24 on the pressure sensor 22.

[Means for Solving Problems] An ultrasonic flowmeter detector according to the present invention is provided with a piezoelectric vibrator having a front plate in contact with a fluid to be measured on one side electrode, and the electrode is electrically connected. A first hollow cylindrical portion having a partition wall for holding the back surface of the piezoelectric vibrator in an airtight state, and a hole communicating with the outside for introducing a measurement fluid, and the inner surface having the first hollow cylindrical portion. A second hollow having a ring made of an acoustic blocking material to be attached, a ring fitted to an end portion, a pressure sensor sensitive to the pressure of a measurement fluid, and a terminal plate connected to each of the pressure sensor and the piezoelectric vibrator. A cylindrical portion is provided, and the first hollow cylindrical portion and the second hollow cylindrical portion are attached via a ring.

[Operation] In the present invention, in a hollow cylinder provided with a piezoelectric vibrator having a front plate for transmitting and receiving ultrasonic waves,
A pressure sensor for measuring the pressure of gas as a measurement fluid is provided, and the first and second hollow cylindrical portions are attached via a ring provided with a gas introduction hole communicating with the outside, and are connected to the piezoelectric vibrator. The pressure sensor can be operated by a single cable that shares its power supply and signal transmission.

Therefore, it is not necessary to install a pressure sensor or a pressure sensor seat on the conduit and to lay a cable, and the piezoelectric vibrator and the pressure sensor are combined in a hollow cylinder to form an integral structure and are installed at the same conduit position. Therefore, it is possible to suppress a difference in the time response of the flow signal and the pressure signal.

[Embodiment] An embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view of a sensor part of a detector for an ultrasonic flowmeter showing an embodiment of the present invention, in which 22 is the same as the conventional detector, 3 is a sensor part, and 4 is a first part. Reference numeral 1 denotes a hollow cylindrical portion, 5 is a piezoelectric vibrator in which ultrasonic waves are transmitted and received and one electrode is connected to the first hollow cylindrical portion 4, and 6 is a measurement fluid fixed to one electrode of the piezoelectric vibrator 5. A front plate 7 for impedance matching with the first hollow cylindrical portion 4 for holding the piezoelectric vibrator 5 in an airtight state.
A partition wall made of an insulating material fixed to the inner peripheral surface of the device, 8 is a hole communicating with the outside to introduce a measurement fluid, 10 is a terminal, 11 is an electric wire for electrical connection, 13 is a second hollow cylindrical portion, and 14 is For example, a pressure sensitive element that uses a semiconductor strain gauge, which is sensitive to the pressure of the measurement fluid, 15 is a signal converter that converts the output of the pressure sensitive element 14 into a pressure signal, and 17 is the piezoelectric vibrator 5 and the signal converter 1.
A terminal board having terminals 10 to which the output signals of 5 are connected, 1
Reference numeral 8 is a ring made of a cylindrical acoustic blocking material having a screw which is engaged with the first hollow cylindrical portion 4 on the inner peripheral surface thereof.

In the ultrasonic flowmeter detector configured as described above, the piezoelectric vibrator 5 having the front plate 6 used for flow rate measurement is fixed to the end face of the measurement fluid that comes into contact with the gas, and the back surface thereof is in an airtight state. The second hollow cylindrical portion 13 provided with the first hollow cylindrical portion 4 held by the pressure sensor 22 and the pressure sensor 22 including the pressure sensitive element 14 and the signal converter 15 is provided with a ring 18 by, for example, respective screws. The sensor part 3 is formed by being attached. The measurement fluid is introduced into the cylinder through a hole 8 provided in parallel with the peripheral surface of the ring 18, and a gas pressure signal is obtained from a pressure sensor 22 which is sensitive to the pressure of the measurement fluid. At the same time, one electrode of the piezoelectric vibrator 5 is connected to the terminal 10 of the terminal plate 17 via the conductive path of the first hollow cylindrical portion 4 made of, for example, a stainless material. The other electrode of the piezoelectric vibrator 5 is connected to the terminal 10 of the terminal plate 17 through the partition wall 7 to obtain a gas flow rate signal.

Since the first and second hollow cylindrical portions 4 and 13 are attached to each other via the ring 18 of the acoustic blocking material made of polyimide or the like and are coupled to the pipeline 20, the pipeline is acoustically blocked from the pipeline 20.
The influence of acoustic noise propagating through the conduit 20 can be avoided.

FIG. 2 shows an outline view of a detector for an ultrasonic flow meter according to the present invention, in which 1 , 1 , 3 , 8, 19, 24, and 25 are the same as those of the conventional device, and 2 is a pipe to a pipe 20. A piezoelectric vibrator 5 and a pressure sensor 22 are provided in a mounting screw for fixing the sonic flow meter detector 1 and the sensor unit 3. Terminal board 1
The signals of flow rate and pressure from 7 are sent out by the cable 24 via the terminal box 25.

According to the present invention, the piezoelectric vibrator 5 having the front plate 6 and the pressure sensor 22 in the sensor part 3 in which the first hollow cylindrical part 4 and the second hollow cylindrical part 13 are engaged with each other with the ring 18 interposed therebetween form the partition wall 7. Since the piezoelectric vibrator 5 is disposed through the holes, the measurement fluid gas is introduced from the hole 8 provided in the ring 18 by only slightly increasing the size of the sensor portion 3 without impairing its operation. Since the flow rate measurement and the pressure measurement can be performed at the same position of the pipe line 20, a simultaneous response can be obtained and the accuracy of the calibration of the flow rate value to the standard state is improved, and the cable 24 is also used for the flow rate measurement and the pressure measurement. As a result, the equipment configuration for ultrasonic flow rate measurement is significantly simplified. The ultrasonic flowmeter detector 1 can be applied to air and various fuel gases.

As described above, since it is unnecessary to lay the pressure sensor seat 23 and the cable 24 for separately installing the pressure sensor 22, it is possible to contribute to cost reduction of equipment and efficiency improvement of equipment.

[Advantage of the Invention] As described above, the present invention provides the piezoelectric vibrator having the front plate in the first hollow cylindrical portion together with the partition wall for maintaining the airtight state, and the pressure sensitive element and the signal in the second hollow cylindrical portion. A simple structure in which a pressure sensor including a transducer is provided, the first hollow cylindrical portion and the second hollow cylindrical portion are engaged with each other with a ring interposed, and a hole for introducing a measurement fluid is provided in parallel with the peripheral surface of the ring. As a result, both the piezoelectric vibrator for measuring the flow rate and the pressure sensor for measuring the pressure are arranged in the first and second hollow cylindrical portions, and both cylindrical portions are connected to obtain the flow rate signal and the pressure signal from the output terminal. By installing a pair of mounting seats for the ultrasonic flowmeter detector in the conduit and laying a cable that transmits both flow rate and pressure signals, the pressure sensor and the seat for the pressure sensor in the conduit can also be installed. No cable laying required Since equipment configuration is also simplified the equipment is considerably simplified in the measuring, instrument cost and equipment cost can be significantly reduced.

Furthermore, since flow rate measurement and pressure measurement can be performed at the same position in the pipeline at the same time, simultaneity of both signals is ensured even for fluid pulsation and sudden pressure fluctuation, and the flow rate value can be calibrated to the standard state with high accuracy. The effect is that it can be done.

[Brief description of drawings]

FIG. 1 is a sectional view of an ultrasonic flowmeter detector sensor portion showing an embodiment of the present invention, FIG. 2 is an external view of an ultrasonic flowmeter detector according to the present invention, and FIG. It is a layout of a detector for an acoustic flow meter. In the figure, 1 is a detector for an ultrasonic flow meter, 2 is a mounting screw, 3 is a sensor part, 4 is a first hollow cylindrical part, 5 is a piezoelectric vibrator, 6 is a front plate, 7 is a partition wall, 8 is a hole, 10 is a terminal, 11
Is an electric wire, 13 is a second hollow cylindrical portion, 14 is a pressure-sensitive element, 15
Is a signal converter, 17 is a terminal plate, 18 is a ring, and 22 is a pressure sensor. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] 1. A hollow cylinder to which a front plate in contact with a measurement fluid is provided at one end of a front plate and which is electrically connected to the electrode, and the other end of the hollow cylinder is provided with a ring for acoustic isolation. In the detector for an ultrasonic flowmeter mounted on a mounting seat provided in a pipe, the piezoelectric vibrator provided at the end of the hollow cylinder and a partition for holding the back surface of the piezoelectric vibrator in an airtight state. The inner surface has a hollow cylindrical portion and a hole communicating with the outside for introducing the measurement fluid.
A ring made of an acoustic blocking material that is attached to the hollow cylindrical portion,
A first hollow cylinder including a pressure sensor that is sensitive to the pressure of the measurement fluid introduced from the hole of the ring, and a second hollow cylindrical portion having a terminal plate connected to the pressure sensor and the piezoelectric vibrator. A detector for an ultrasonic flowmeter, in which the second portion and the second hollow cylindrical portion are attached via a ring.